JPH11170548A - Manufacture of print head for ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a print head of high dimensional accuracy by eliminating the bonding process. SOLUTION: The print head of an ink jet printer comprises a liquid chamber 6 defined by a nozzle plate 1, a liquid chamber barrier walk 3 and a diaphragm 5 and jets an ink drop from a nozzle hoe 9 made in the nozzle plate 1 by generating an inner pressure in an ink filling the liquid chamber 6 through deformation of the diaphragm 5 thus printing on a recording medium. The nozzle plate 1, the liquid chamber barrier wall 3 and the diaphragm 5 are formed integrally without passing through a bonding step at all.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention performs printing on a recording medium by generating an internal pressure in a liquid chamber by deforming a diaphragm constituting a part of the liquid chamber and discharging ink droplets from nozzle holes. The present invention relates to a method of manufacturing a print head of an on-demand type ink jet printer, and more particularly to a method of integrally forming a nozzle plate, a liquid chamber partition, and a vibration plate.

Here, as a method of deforming the diaphragm, it is conceivable to use, as a drive element, a material that generates some amount of displacement in response to an electric signal, such as a piezoelectric material, a dielectric material, a magnetic material, or a shape memory alloy. The demand type is a recording method in which ink is ejected in response only when an electric signal is input.

[0003] Further, the printer mentioned here is paper, cloth,
It is a recording device that prints on a recording medium such as wood, glass, metal, and the like. Today, it is widely used not only for peripheral devices of computers but also for industrial applications such as FAX, word processor, and POS. Obviously, the printing there includes not only characters and figures but also barcodes, wood grain, and other patterns that have no particular meaning.

[0004] In addition, the term "integral" here means that parts having different functions are formed simultaneously by a single process, or are processed to a target shape by the action of erosion or deposition, and steps such as bonding are used. It means that there is not.

[0005]

2. Description of the Related Art In order to realize and improve the performance required of a printer such as maintenance-free, high-speed printing, and high-resolution printing, it is necessary to increase the number of nozzles and the driving frequency of a print head having long-term reliability. thing,
It is necessary to improve the ink landing accuracy, etc. In connection with this, it is necessary to optimize the shape of the liquid chamber and the dimensional accuracy of the nozzle holes, optimize the rigidity of the diaphragm, etc., and perform water repellent treatment of the nozzle plate, etc. However, up to now, print heads have been manufactured by manufacturing each component such as the liquid chamber partition, diaphragm and nozzle plate independently to the optimum value, and joining them with adhesive with high alignment accuracy. Was.

FIG. 22 is a simple cross-sectional view of a print head using a piezoelectric element as a driving element, which is manufactured by a conventional method. From the relationship between the deformation direction of the diaphragm and the ink droplet ejection direction, FIG. 22A is called an end face ejection type, and FIG.
Is called a surface discharge type.

The nozzle plate 1 in FIG.
It is made by rolling a 0 μm stainless steel plate or by nickel electroforming using a plastic matrix. Water repellency is given to the nozzle plate front side by Teflon eutectoid plating or the like. The nozzle holes 9 have a diameter of about 40 μm and are arranged in accordance with the liquid chamber 6.

The liquid chamber partition 3 is manufactured in consideration of mechanical rigidity and the like in accordance with the performance of the printer, but is often manufactured by injection molding or laser processing of plastic or the like. In the case of injection molding, an epoxy-based thermoplastic resin is used, and in the case of laser processing, a material having a suitable light absorption wavelength such as polysulfone is selected to obtain good processing accuracy.

The vibrating plate 5 is manufactured by nickel electrocasting to a thickness of about 5 μm, and provided with a vibrating rod 21 having a projection shape corresponding to the position of each liquid chamber. This serves to transmit the deformation of the driving element 103 to the diaphragm 5 efficiently, loosen the tolerance of the alignment accuracy with the liquid chamber 6, and facilitate the adhesion between the diaphragm and the driving element.

The driving element 103 is made of lead zirconate titanate, and is formed by sintering a laminate of green sheets and electrodes alternately. In this example, the fired material is cut into a rectangular parallelepiped, joined to the base 107, and then subjected to groove cutting with a wire saw in accordance with the liquid chamber pitch. The drive element 103 is polarized in the direction from the base 107 to the diaphragm 5, and a common electrode and a drive electrode are alternately stacked inside the drive element. When a groove is formed by a wire saw, the internal electrodes are also separated, so that by applying a voltage in parallel with the polarization direction, each peak can be driven independently.

[0011] To what was made by bonding these parts,
Further, a driving circuit for giving an electric signal to the driving element,
An ink tank for supplying ink and a print head including a holder for combining them are called a print head, and an ink jet printer including a paper feed mechanism and a maintenance mechanism. Above all, since it relates to a method of forming a nozzle plate, a liquid chamber partition wall, and a diaphragm, a combination of only these three points is also referred to as a print head for convenience.

[0012]

Most of the components constituting these print heads are positioned with high precision, and a thermosetting resin is applied by a screen printing method or the like and joined. In the case of the adhesive, a temperature is applied to the component, so that thermal expansion occurs. Due to a difference in the coefficient of thermal expansion, a positional shift is likely to occur on the joint surface. In addition, the adhesive tends to break off during screen printing due to its own viscosity, or conversely, overflow of the adhesive due to a large amount of adhesion.If the adhesive is insufficient, the parts will peel due to insufficient strength, and ink will seep out. , Etc., and the protrusion of the adhesive causes a change in the natural frequency and the attachment of air bubbles in the liquid chamber, causing variations in characteristics between heads.

In other words, in the case of manufacturing a print head having high characteristics, the quality of the bonding technique is a major factor influencing the performance of the head, and the special devices required for that purpose increase the manufacturing cost. ing. Recently, due to the demand for improved printing performance, the nozzle spacing has been reduced and the number of nozzles has been increased accordingly.
If the head is designed with a resolution of 180 dpi (nozzle interval of 141 μm pitch), the width of the liquid chamber 6 is expected to be about 90 μm and the thickness of the wall is about 50 μm, which is approaching the limit of the bonding method using the screen printing method. Regarding the positioning accuracy of the parts, even if the processing accuracy of each part is improved, the method of superimposing the individually manufactured parts inevitably has a variation of several tens of μm. The energy of the element cannot be efficiently directed to ink ejection, and the original performance cannot be sufficiently exhibited.

In order to solve these problems, several methods have been disclosed in which a liquid chamber partition and a vibration plate or a nozzle plate are integrally formed to omit a bonding step. For example, JP-A-9-85
No. 949 discloses that in forming a liquid chamber using anisotropic etching of silicon, a diaphragm and a driving element are formed on a silicon wafer in advance, and then anisotropic etching is performed. (FIG. 23). In the present invention, there is an advantage that the drive elements can be integrated, but when the pitch of the liquid chambers is small, it becomes difficult to form the drive elements. In addition, since the problem of adhesion of the nozzle plate remains, it is not a sufficient method for integration at a narrow pitch.

In Japanese Patent Application Laid-Open No. 9-70964, the step of bonding the nozzle plate and the liquid chamber is avoided by using injection molding (FIG. 24). Injection molding is advantageous as an integration method because it has a high degree of freedom in shape and can significantly reduce processing costs, but it is also difficult to form deep grooves due to mold release properties when the liquid chamber has a narrow pitch. In the case of a thermoplastic resin, the liquid chamber partition wall becomes thinner, and the strength becomes gradually insufficient. Furthermore, the process of bonding the diaphragm cannot be avoided, and is not a sufficient solution to the problem.

[0016]

In order to solve the above-mentioned problems, the present invention employs the following configuration.

That is, a method of manufacturing a print head of an ink jet printer according to the present invention has a liquid chamber surrounded by a nozzle plate, a liquid chamber partition, and a vibration plate, and the deformation of the vibration plate is filled in the liquid chamber. A print head of an ink jet printer that generates internal pressure in ink and discharges ink droplets from nozzle holes formed in the nozzle plate to enable printing on a recording medium, wherein one surface of a single crystal silicon wafer is provided. Is a surface A, (1) a step of forming a first metal film composed of at least one layer over the entire surface A of the single crystal silicon wafer, and (2) a step of forming a first metal film on the surface opposite to the surface A of the single crystal silicon wafer. Forming a second metal film of at least one layer on the entire surface of a certain surface B; and (3) photolithography on the surface B of the single crystal silicon wafer. Forming a first photosensitive resist patterned by a luffy method, and using the first photosensitive resist as a first mask, forming a nozzle hole and a plurality of openings in the second metal film by an etching method; Removing the first photosensitive resist after forming the portion, and (4) a predetermined film required as the diaphragm over the entire surface of the first metal film on the surface A of the single crystal silicon wafer Forming a diaphragm film having a thickness; and (5) using the second metal film on the surface B of the single crystal silicon wafer as a part of the liquid chamber partition as a second mask, (6) a step of performing anisotropic etching of the wafer; and (6) applying a second photosensitive resist patterned by photolithography on the diaphragm film on the surface A of the single crystal silicon wafer. And (7) a step of forming a third metal film composed of at least one layer on the entire surface of both surfaces of the single-crystal silicon wafer, and stripping the second photosensitive resist. I do.

Alternatively, there is provided a liquid chamber surrounded by a nozzle plate, a liquid chamber partition wall, and a vibration plate, and the deformation of the vibration plate generates an internal pressure in the ink filled in the liquid chamber, and is formed on the nozzle plate. A print head of an ink jet printer that enables printing on a recording medium by ejecting ink droplets from a nozzle hole, wherein one surface of a single crystal silicon wafer is defined as a surface A. Forming a first metal film of at least one layer over the entire surface of the surface A; and (2) forming a first metal film patterned by photolithography on the surface B opposite to the surface A of the single crystal silicon wafer. (1) forming a photosensitive resist, and forming a second metal film composed of at least one layer on the entire surface of the surface B; Peeling the photosensitive resist, the surface B
Forming a nozzle hole and a plurality of openings in the second metal film, and (4) forming the vibration plate over the entire surface of the first metal film on the surface A of the single crystal silicon wafer. Forming a diaphragm film having a predetermined thickness; and (5) using the second metal film on the surface B of the single crystal silicon wafer as a mask as a part of the liquid chamber partition wall as a mask. A step of performing anisotropic etching of the wafer; and (6) a step of forming a second photosensitive resist patterned by photolithography on the diaphragm film on the surface A of the single crystal silicon wafer. And (7) a step of forming at least one third metal film on the entire surface of both surfaces of the single-crystal silicon wafer, and stripping the second photosensitive resist. That.

Alternatively, there is provided a liquid chamber surrounded by a nozzle plate, a liquid chamber partition wall, and a vibration plate, and the deformation of the vibration plate generates an internal pressure in the ink filled in the liquid chamber, and is formed on the nozzle plate. A print head of an ink jet printer that enables printing on a recording medium by ejecting ink droplets from a nozzle hole, wherein one surface of a single crystal silicon wafer is defined as a surface A. Forming a first metal film of at least one layer on the entire surface of the surface A; and (2) silicon nitride, oxide or carbide of silicon on the entire surface of the surface B opposite to the surface A of the single crystal silicon wafer. (3) forming a second metal film of at least one layer over the entire surface B of the single crystal silicon wafer. And (4) forming a patterned first photosensitive resist on the surface B of the single crystal silicon wafer by photolithography, and etching using the first photosensitive resist as a first mask. Forming a nozzle hole and a plurality of openings in the second metal film by a method, and removing the first photosensitive resist; and (5) photolithography on the surface B of the single crystal silicon wafer. A third photosensitive resist patterned by using a method is formed, and a nozzle hole and a plurality of openings are formed in the insulating film by etching using the third photosensitive resist as a third mask. Thereafter, a step of removing the third photosensitive resist,
(6) a step of forming a diaphragm film having a predetermined thickness required as the diaphragm on the entire surface of the first metal film on the surface A of the single crystal silicon wafer; and (7) the liquid chamber partition wall. Surface B of the single crystal silicon wafer as part of
Performing anisotropic etching of the single-crystal silicon wafer using the insulating film as a second mask,
(8) forming a second photosensitive resist patterned by photolithography on the diaphragm film on the surface A of the single-crystal silicon wafer;
(9) forming a third metal film composed of at least one layer on both surfaces of the single crystal silicon wafer, and removing the second photosensitive resist.

Alternatively, in the above-described method for manufacturing a print head, before the step of forming a first metal film comprising at least one layer on the entire surface A of the single crystal silicon wafer, (0) A step of forming an insulating film containing at least one of silicon nitride, oxide, and carbide on the entire surface of the surface A;

Alternatively, in the above-described method of manufacturing a print head, the anisotropic etching may be performed by adjusting the etching depth to include at least one of the silicon nitride, oxide and carbide on the surface A of the single crystal silicon wafer. The process is performed until the insulating film is reached.

Alternatively, in the above-described method for manufacturing a print head, the depth of etching in the anisotropic etching is set to the first depth on the surface A of the single crystal silicon wafer.
Until the metal film is reached.

Alternatively, in the above-described method for manufacturing a print head, the depth of etching in the anisotropic etching is set to the first depth on the surface A of the single crystal silicon wafer.
After arriving at the first metal film, the surface of the first metal film is oxidized.

Alternatively, in the above-described method for manufacturing a print head, the etching depth in the anisotropic etching is set to the first depth on the surface A of the single crystal silicon wafer.
Before reaching the metal film.

Alternatively, in the above-described method for manufacturing a print head, the depth of etching in the anisotropic etching is set to the first depth on the surface A of the single crystal silicon wafer.
After stopping before reaching the first metal film and forming the third metal film, anisotropic etching is performed again until the first metal film is reached.

Alternatively, in the above-described method for manufacturing a print head, the plurality of openings formed in the second metal film may be formed by forming a slit-shaped pattern having a combination of several widths, lengths, and angles into the liquid chamber partition wall. Are arranged in parallel in the same direction as the longitudinal direction.

Alternatively, in the above-described method of manufacturing a print head, the width of the slit-shaped pattern is regulated to be twice or less the thickness of the single-crystal silicon wafer.

Alternatively, in the above-described method of manufacturing a print head, the arrangement interval of the slit-shaped patterns is set to a distance that allows adjacent openings to communicate with each other by side etching that occurs when the anisotropic etching is performed. It is characterized by being set.

Alternatively, in the above-described method for manufacturing a print head, the diaphragm film is formed by an electrolytic plating method.

Alternatively, in the above-described method for manufacturing a print head, the diaphragm film is made of nickel or gold.

Alternatively, in the above-described method for manufacturing a print head, the third metal film is formed by an electrolytic plating method.

Alternatively, in the above-described method for manufacturing a print head, the third metal film is made of nickel or gold.

Alternatively, in the above-described method of manufacturing a print head, the third metal film is provided with a water-repellent surface.

Alternatively, in the above-described method of manufacturing a print head, the single crystal silicon wafer has a crystal orientation of (11
0) or (100), and both surfaces AB are mirror-polished.

(Function) According to the present invention, in a method of manufacturing a print head of an ink jet printer, a combination of anisotropic etching technology of a single crystal silicon wafer and electroforming technology utilizing a photolithography method is used.
Since the liquid chamber partition, diaphragm, and nozzle plate can be manufactured integrally, a print head can be manufactured without having to go through a bonding process that impairs the joining accuracy and printing characteristics. Since room processing can be performed, there is almost no dimensional error even if the nozzle holes have a high density, and it is possible to manufacture a print head of an ink jet printer having high characteristics.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to examples.

[0037]

(Embodiment 1) FIGS. 1 and 2 show a simple manufacturing process diagram of a print head made by the present invention. (A) ~
(L) represents the order of the steps. The process diagram is a cross-sectional view in which the liquid chamber portion of the print head is cut along the line XX ′ in FIG. In the single crystal silicon wafer, the side on which the diaphragm is formed is referred to as surface A, and the side on which a plurality of openings are formed is referred to as surface B. In the figure, the lower side is represented by surface A, and the upper side is represented by surface B.

First, both sides are polished to a thickness of about 300 μm.
A first metal film is formed on the surface A and a second metal film is formed on the surface B by vacuum deposition on the entire surface A and surface B of the single crystal silicon wafer 7 having a crystal orientation of (110) (FIG. 1 (a)). Each of the metal films is composed of a chromium film 51 having a thickness of about 400 Å as an adhesion layer and a gold film 53 having a thickness of about 2000 Å as a conductive layer and an etchant-resistant layer.

In this embodiment, the metal film is composed of chromium and gold for both the first metal film and the second metal film. However, it is possible to use titanium or platinum instead of chromium and nickel or platinum instead of gold. There is no problem in the invention. In addition, although the method of forming the metal film is also performed by vacuum deposition in this embodiment,
Instead, sputtering, chemical vapor deposition (hereinafter, referred to as CVD), plating, or the like may be used.

Next, a positive photosensitive resist 55 as a first photosensitive resist is applied to the entire surface B to a thickness of about 2 μm by a spin coater, and prebaked using a hot plate or the like. Similarly, FIG.
(B).

Using a quartz mask 57 on which a pattern as shown in FIG. 21A is drawn, the surface B is exposed to ultraviolet light as shown in FIG. When post-baking is performed after drying, the exposed portions are dissolved, and a pattern similar to a quartz mask is formed on the positive photosensitive resist 55 as shown in FIG.

Here, the positive photosensitive resist 55 on the surface A is used.
Was formed as a protective film for protecting the gold film 53 from an etchant in the next step.

Next, using the exposed and developed positive photosensitive resist 55 as a first mask, the gold film 53 is etched with aqua regia (mixed solution of nitric acid and hydrochloric acid, mixing ratio of 1: 1 to 1: 3). . Further, the chromium film 51 is coated with a mixed aqueous solution of cerium ammonium nitrate and perchloric acid (for example, 20 g of cerium ammonium nitrate and 20 ml of perchloric acid per 1 L of pure water).
The gold film 53 and the chromium film 5
1 is patterned into the same shape as the positive photosensitive resist 55, and a plurality of openings (A in FIG. 21 (a)) and nozzle holes (FIG. 21 (a)) for forming liquid chamber partitions are formed.
B) is formed on the surface B as shown in FIG. After the patterning of the chromium film and the gold film, the positive photosensitive resist 55 is removed with a dedicated stripper for the next step, and the shape becomes as shown in FIG.

Here, a plurality of openings are formed in the second metal film by wet etching, but sputter etching or reactive ion etching may be used.

In order to form a diaphragm film, the gold film 53, which is a part of the first metal film on the surface A, is sufficiently ashed by oxygen plasma or the like, and then this is used as an electrode to form a nickel 59
Is grown to a thickness of about 5 μm by electrolytic plating. This stage is a plating step for forming a diaphragm, and nickel is simultaneously grown on the surface B, as a result, as shown in FIG. 1 (g).

Since silicon and gold have significantly different specific resistance values, nickel 59 mostly grows on the gold film 53 and does not grow on the silicon wafer 7 during the electrolytic plating step, so that the dimensional accuracy of the patterned gold film is reduced. Does not affect

At this time, the surface B may be protected with a photosensitive resist or the like so that nickel does not grow.
At this time, since the thickness of the metal film is very thin, about 2400 angstroms, hydrogen gas or the like generated when performing anisotropic etching of the silicon wafer 7 using the second metal film as a second mask in the next step. It is also conceivable that a part of the second metal film is torn or deformed by stress. Since the second metal film has an important role in forming the nozzle plate in the present invention, it is possible to form nickel 59 on the second metal film at the same time as forming the diaphragm as in this embodiment. Strength can be supplemented and dimensional accuracy can be increased.

In this embodiment, nickel is used as the diaphragm by electrolytic plating. However, the material may be gold, platinum, etc. as long as the diaphragm has rigidity and resistance to the etchant of anisotropic etching. Also available. Also, the forming method is not limited to the electrolytic plating method, but also includes sputtering and CVD.
Also available.

The silicon wafer 7 having undergone the above steps is 3
When immersed in a 0 wt% aqueous solution of potassium hydroxide at about 70 ° C., silicon starts to be etched anisotropically from the nozzle hole and the plurality of openings (FIG. 1 (h)).
At this time, as shown in FIG. 21 (a), the plurality of openings have a structure in which a plurality of slit-like patterns each having a width of about 30 μm are arranged in parallel, and a process in which side etching proceeds from these openings. The spaces are communicated with each other, and a liquid chamber partition wall, a vibration plate, and a liquid chamber of the print head finally obtained are obtained.

At this time, since nickel 59 has strong resistance to the aqueous solution of potassium hydroxide, it does not erode without special protection.

FIG. 1 (i) shows the state when the anisotropic etching reaches the chromium film 51. When the anisotropic etching proceeds from the plurality of slit-shaped openings and penetrates the silicon wafer, the surface of the diaphragm seen from the liquid chamber 6 side looks like a chromium film 51 previously applied. Similarly, the side where the bridge-like structure, which is a part of the second metal film remaining on the surface B side, faces the liquid chamber 6, also has the chromium film 51. When the chromium film 51 is subjected to surface treatment in an atmosphere in which ozone is generated by irradiating ultraviolet rays to the atmosphere, a chromium oxide layer is obtained on the surface.

If the chromium film 51 is opened on the surface of the diaphragm viewed from the liquid chamber 6 at the time of electrolytic plating in the next step, nickel plating may grow there. It plays a role to avoid.

In this case, an ultraviolet irradiation type ozone washing machine is used to obtain a chromium oxide layer. However, heat treatment in an oxygen atmosphere or oxygen plasma treatment under a low pressure may be used. The method is conceivable.

Next, a positive photosensitive resist 55 as a second photosensitive resist is applied to a thickness of about 5 μm as a second photosensitive resist by a bar coater or the like, and is exposed and developed to form a pattern of a vibration transmission rod ( FIG. 2 (j)).

Thereafter, the nickel film 59 adhered to the surface of the second metal film when the diaphragm film was formed was used as an electrode.
Further, nickel electroplating is performed as a third metal film until the plurality of openings are closed. This step is referred to as a nozzle plate forming plating step.

Since the electrolytic plating has a feature of growing in all directions from the electrode to the space, the plating layer grows from the electrode on the bridge-like structure also in the in-plane direction of the silicon wafer to form a plurality of openings. Can be blocked. In the case of this embodiment, the width of the slit-shaped opening is set to 30 μm, so that the nickel plating layer as the third metal film has a thickness of 1 μm.
What is necessary is just to grow 5 micrometers or more.

Further, the nozzle hole which is expected to have a larger opening area than the opening does not close in this nozzle plate forming plating step. FIG. 2 (k) shows a state in which the opening is closed and the nickel film 59, which becomes a vibration transmission rod, has grown to an appropriate size thereafter.

Thereafter, the positive photosensitive resist 55 is removed, and after cleaning and surface treatment, a print head is obtained in which the desired nozzle plate 1, liquid chamber partition 3, vibration plate 5 and vibration transmission rod 21 are integrated. (FIG. 2 (l)).

At this time, the structure of the film of the diaphragm is a chromium film, a gold film, and a nickel film as viewed from the liquid chamber side.

In this embodiment, the vibration transmission rod and the third metal film are formed simultaneously by electrolytic plating, but may be formed separately. As one example of such a case, after forming the vibration plate 5, after protecting the surface B with a photosensitive resist, a second photosensitive resist is formed on the surface A, and a vibration transmission rod is formed by electrolytic plating. The anisotropic etching of the single crystal silicon wafer may be performed by removing the photosensitive resist.

FIGS. 27, 28, 29, and 30 show SEM images of samples actually formed by using this embodiment.
The samples of these SEM images are those in which the mask pattern is composed of only a plurality of openings (A in FIG. 21A), in which a nickel electrolytic plating layer serving as a nozzle plate is copied from the liquid chamber side. It is. Although the diaphragm is removed for photographing, it is integrally formed after manufacturing.

FIG. 27 shows a state where a plurality of openings are completely filled with a nickel plating layer. FIG. 28 is a partially enlarged view of FIG. FIG. 29 shows a state in which a plurality of openings are not yet completely filled in the middle of nickel plating. FIG. 30 is a partially enlarged view of FIG.

The above is one of the embodiments of the present invention. In the first embodiment, when forming the third metal film,
The diaphragm has a step of oxidizing the chromium film as a means for suppressing the formation of a metal film of the same material on the diaphragm. However, there are some other methods for dealing with the same problem. The following example shows a manufacturing method for obtaining a target print head without using an oxidation step.

(Embodiment 2) FIGS. 3 and 4 show a simple manufacturing process diagram of a print head made by the present invention. (A)
-(L) represents the order of the steps. The process diagram is a cross-sectional view in which the liquid chamber portion of the print head is cut along the line XX ′ in FIG. In the single crystal silicon wafer, the side on which the diaphragm is formed is referred to as surface A, and the side on which a plurality of openings are formed is referred to as surface B. In the figure, the lower side is represented by surface A, and the upper side is represented by surface B.

First, both sides are polished to a thickness of about 300 μm.
A first metal film is formed on the surface A and a second metal film is formed on the surface B by vacuum deposition on the entire surface A and surface B of the single crystal silicon wafer 7 having a crystal orientation of (110) (FIG. 3 (a)). Each of the metal films is composed of a chromium film 51 having a thickness of about 400 Å as an adhesion layer and a gold film 53 having a thickness of about 2000 Å as a conductive layer and an etchant-resistant layer.

In this embodiment, the metal film is composed of chromium and gold for both the first metal film and the second metal film. However, it is possible to use titanium or platinum instead of chromium and nickel or platinum instead of gold. There is no problem in the invention. In addition, although the method of forming the metal film is also performed by vacuum deposition in this embodiment,
Instead, sputtering, CVD, plating, or the like may be used.

Next, a positive photosensitive resist 55 as a first photosensitive resist is applied to the entire surface B to a thickness of about 2 μm by a spin coater, and prebaked using a hot plate or the like. Similarly, for the surface A, FIG.
(B).

The surface B is exposed to ultraviolet light as shown in FIG. 3C using a quartz mask 57 on which a pattern as shown in FIG. When post-baking is performed after drying, the exposed portions are dissolved, and a pattern similar to a quartz mask is formed on the positive photosensitive resist 55 as shown in FIG.

Here, the positive photosensitive resist 55 on the surface A is used.
Was formed as a protective film for protecting the gold film 53 from an etchant in the next step.

Next, using the exposed and developed positive photosensitive resist 55 as a first mask, the gold film 53 is etched with aqua regia (mixed solution of nitric acid and hydrochloric acid, mixing ratio of 1: 1 to 1: 3). . Further, the chromium film 51 is coated with a mixed aqueous solution of cerium ammonium nitrate and perchloric acid (for example, 20 g of cerium ammonium nitrate and 20 ml of perchloric acid per 1 L of pure water).
The gold film 53 and the chromium film 5
1 is patterned into the same shape as the positive photosensitive resist 55, and a plurality of openings (A in FIG. 21 (a)) and nozzle holes (FIG. 21 (a)) for forming liquid chamber partitions are formed.
B) is formed on the surface B as shown in FIG. After the patterning of the chromium film and the gold film, the positive photosensitive resist 55 is removed by a dedicated stripping solution for the next step, and the shape becomes as shown in FIG.

Here, a plurality of openings are formed in the second metal film by wet etching, but sputter etching or reactive ion etching may be used.

After a gold film 53 which is a part of the first metal film on the surface A is ashed sufficiently with oxygen plasma or the like to form a diaphragm film, the nickel film 5 is used as an electrode.
9 is grown by electrolytic plating to a thickness of about 5 μm. This step is referred to as a diaphragm forming plating step, and nickel is simultaneously grown on the surface B. As a result, the result is as shown in FIG.

Since the specific resistance values of silicon and gold are greatly different, the nickel film 59 grows mostly on the gold film 53 and does not grow on the silicon wafer 7 during the electrolytic plating step. It does not affect accuracy.

At this time, the surface B may be protected with a photosensitive resist or the like so that nickel does not grow.
At this time, since the thickness of the metal film is very thin, about 2400 angstroms, hydrogen gas or the like generated when performing anisotropic etching of the silicon wafer 7 using the second metal film as a second mask in the next step. It is also conceivable that a part of the second metal film is torn or deformed by stress. Since the second metal film plays an important role in forming the nozzle plate in the present invention, it is necessary to grow the nickel film 59 on the second metal film at the same time as forming the diaphragm as in this embodiment. Can supplement the strength and improve the dimensional accuracy.

In this embodiment, nickel is used as the diaphragm by electrolytic plating. However, the material may be gold, platinum or the like, as long as the diaphragm has rigidity and resistance to the etchant of anisotropic etching. Also available. Also, the forming method is not limited to the electrolytic plating method, but also includes sputtering and CVD.
Also available.

The silicon wafer 7 having undergone the above steps is 3
When immersed in a 0 wt% aqueous solution of potassium hydroxide at about 70 ° C., silicon starts to be etched anisotropically from the nozzle hole and the plurality of openings (FIG. 3 (h)).
At this time, as shown in FIG. 21A, the plurality of openings have a structure in which a plurality of slit-like patterns each having a width of about 30 μm are arranged in parallel, and a process in which side etching proceeds from these openings. Spaces communicate with each other in
Finally, the desired liquid chamber partition wall, diaphragm and liquid chamber of the print head are obtained.

At this time, since the nickel film 59 has a strong resistance to the aqueous solution of potassium hydroxide, it does not erode without special protection.

Here, in this embodiment, the anisotropic etching is interrupted once, and silicon is left several μm as viewed from the diaphragm. The state up to this point is shown in FIG.

This is because if the first metal film is opened on the surface of the diaphragm viewed from the liquid chamber 6 at the time of electrolytic plating in the next step, nickel plating may grow there. The role is to avoid.

Next, a positive photosensitive resist 55 is applied as a second photosensitive resist on the surface of the vibration plate to a thickness of about 5 μm with a bar coater or the like, and is exposed and developed to form a pattern of a vibration transmission rod ( FIG. 4 (j)).

Thereafter, the nickel film 59 adhered to the surface of the second metal film when the diaphragm film was formed was used as an electrode.
Further, nickel electroplating is performed as a third metal film until the plurality of openings are closed. This step is referred to as a nozzle plate forming plating step.

Since the electrolytic plating has a feature of growing in all directions from the electrode to the space, the plating layer grows from the electrode on the bridge-like structure also in the in-plane direction of the silicon wafer to form a plurality of openings. Can be blocked. In the case of this embodiment, the width of the slit-shaped opening is set to 30 μm, so that the nickel plating layer as the third metal film has a thickness of 1 μm.
What is necessary is just to grow 5 micrometers or more.

The nozzle hole whose opening area is expected to be larger than the opening does not close in the plating process for forming the nozzle plate. FIG. 4K shows a state where the opening is closed and the nickel film 59 has grown to an appropriate size.

Thereafter, after the positive photosensitive resist 55 is removed, washing and surface treatment are performed to obtain the desired nozzle plate 1,
A print head in which the liquid chamber partition 3, the vibration plate 5, and the vibration transmission rod 21 are integrated is obtained (FIG. 4 (l)).

At this time, the structure of the film of the diaphragm is a silicon, chromium film, gold film, and nickel film when viewed from the liquid chamber side. If the silicon portion does not have an appropriate thickness as a diaphragm, the positive photosensitive resist 55 is removed, and then the silicon wafer is again subjected to anisotropic etching with a potassium hydroxide aqueous solution.

In this embodiment, the vibration transmitting rod and the third metal film are formed simultaneously by electrolytic plating, but they may be formed separately as a matter of course. As one example of such a case, after forming the vibration plate 5, after protecting the surface B with a photosensitive resist, a second photosensitive resist is formed on the surface A, and a vibration transmission rod is formed by electrolytic plating. The anisotropic etching of the single crystal silicon wafer may be performed by removing the photosensitive resist.

The following is a manufacturing method for obtaining a target print head without using an oxidation step, following Example 2.

(Embodiment 3) FIGS. 5 and 6 show a simple manufacturing process diagram of a print head manufactured by the present invention. (A)
-(M) represents the order of the steps. The process diagram is a cross-sectional view in which the liquid chamber portion of the print head is cut along the line XX ′ in FIG. In the single crystal silicon wafer, the side on which the diaphragm is formed is referred to as surface A, and the side on which a plurality of openings are formed is referred to as surface B. In the figure, the lower side is represented by surface A, and the upper side is represented by surface B.

First, both sides are polished to a thickness of about 300 μm.
A silicon nitride film 63 having a thickness of 1000 angstroms is formed on the entire surface A of the single crystal silicon wafer 7 having a crystal orientation of (110) by CVD or the like (FIG. 5).
(A)).

Further, a first metal film is formed on the surface A and a second metal film is formed on the surface B by vacuum evaporation (FIG. 5B). Each of the metal films is composed of a chromium film 51 having a thickness of about 400 Å as an adhesion layer and a gold film 53 having a thickness of about 2000 Å as a conductive layer and an etchant-resistant layer.

In this embodiment, the metal film is composed of chromium and gold for both the first metal film and the second metal film. However, even if titanium is used instead of chromium and nickel or platinum is used instead of gold, the present invention is applicable. There is no problem in the invention. In addition, although the method of forming the metal film is also performed by vacuum deposition in this embodiment,
Instead, sputtering, CVD, plating, or the like may be used. In addition, silicon carbide, silicon oxide formed by a thermal oxidation method, or the like can be used for the silicon nitride portion.

Next, a positive photosensitive resist 55 as a first photosensitive resist is applied to the entire surface B to a thickness of about 2 μm by a spin coater, and prebaked using a hot plate or the like. FIG. 5 (c) shows the result obtained in the same manner on the entire surface A.
It is.

The surface B was exposed to ultraviolet light as shown in FIG. 5D using a quartz mask 57 on which a pattern as shown in FIG. 21A was drawn, and developed with a dedicated developer. When post-baking is performed after drying, the exposed portion is dissolved and a pattern similar to that of the quartz mask is formed on the positive photosensitive resist 55 as shown in FIG.

Here, the positive photosensitive resist 55 on the surface A is used.
Was formed as a protective film for protecting the gold film 53 from an etchant in the next step.

Next, using the exposed and developed positive photosensitive resist 55 as a first mask, the gold film 53 is etched with aqua regia (mixed solution of nitric acid and hydrochloric acid, mixing ratio of 1: 1 to 1: 3). . Further, the chromium film 51 is coated with a mixed aqueous solution of cerium ammonium nitrate and perchloric acid (for example, 20 g of cerium ammonium nitrate and 20 ml of perchloric acid per 1 L of pure water).
The gold film 53 and the chromium film 5
1 is patterned into the same shape as the positive photosensitive resist 55, and a plurality of openings (A in FIG. 21A) and nozzle holes (FIG. 21A) for forming liquid chamber partitions are formed.
B) is formed on the surface B as shown in FIG. After the patterning of the chromium film and the gold film, the positive photosensitive resist 55 is removed by a dedicated stripping solution for the next step, and the shape becomes as shown in FIG.

Here, a plurality of openings are formed in the second metal film by wet etching, but sputter etching or reactive ion etching may be used.

After a gold film 53 which is a part of the first metal film on the surface A is ashed sufficiently with oxygen plasma or the like to form a diaphragm film, the nickel film 5 is used as an electrode.
9 is grown by electrolytic plating to a thickness of about 5 μm. This step is referred to as a diaphragm forming plating step, and nickel is simultaneously grown on the surface B. As a result, the result is as shown in FIG.

Since the specific resistance values of silicon and gold are significantly different, the nickel film 59 almost grows on the gold film 53 and does not grow on the silicon wafer 7 during the electrolytic plating step. It does not affect accuracy.

At this time, the surface B may be protected by a photosensitive resist or the like so that nickel does not grow. However, since the second metal film has a very small thickness of about 2400 angstroms, When performing anisotropic etching of the silicon wafer 7 using the second metal film as a second mask in the process, a part of the second metal film is broken by a generated hydrogen gas or the like, or is deformed by stress. It is also possible. Since the second metal film plays an important role in forming the nozzle plate in the present invention, it is necessary to grow the nickel film 59 on the second metal film at the same time as forming the diaphragm as in this embodiment. Can supplement the strength and improve the dimensional accuracy.

In this embodiment, the diaphragm is made of nickel by electrolytic plating, but the diaphragm may be made of any material such as gold or platinum as long as the diaphragm has rigidity and resistance to the etchant of anisotropic etching. Also available. Also, the forming method is not limited to the electrolytic plating method, but also includes sputtering and CVD.
Also available.

In this embodiment, since the silicon nitride film is present, the thickness of nickel is adjusted in consideration of the rigidity of the diaphragm. In this case, the thickness of the silicon nitride is 100
Although it is 0 Å, nickel may not be particularly necessary when the thickness is about 1 μm. At this time,
The vibration plate forming plating step is a step for forming nickel on the second metal film.

The silicon wafer 7 having undergone the above steps is 3
When immersed in a 0 wt% aqueous solution of potassium hydroxide at about 70 ° C., silicon starts to be etched anisotropically from the nozzle hole and the opening formed of a plurality (FIG. 5 (i)).
At this time, the plurality of openings have a configuration in which a plurality of slit-like patterns each having a width of about 30 μm are arranged in parallel as shown in FIG. 21A, and the process in which the side etching proceeds from these openings. Spaces communicate with each other in
Finally, the desired liquid chamber partition wall, diaphragm and liquid chamber of the print head are obtained.

At this time, since the nickel film 59 has strong resistance to the aqueous solution of potassium hydroxide, it does not erode without special protection.

FIG. 6 (j) shows a state where the anisotropic etching reaches the silicon nitride film 63. When the anisotropic etching proceeds from the plurality of slit-shaped openings and penetrates the silicon wafer, the surface of the diaphragm seen from the liquid chamber 6 side becomes the silicon nitride film 63 previously formed.
Appears.

This is because if the first metal film is opened on the surface of the diaphragm viewed from the liquid chamber 6 at the time of electrolytic plating in the next step, nickel plating may grow there. The role is to avoid.

Next, a positive photosensitive resist 55 is applied as a second photosensitive resist on the surface of the vibration plate to a thickness of about 5 μm with a bar coater or the like, and is exposed and developed to form a pattern of a vibration transmission rod ( FIG. 6 (k)).

Thereafter, the nickel film 59 adhered to the surface of the second metal film when the diaphragm film was formed was used as an electrode.
Further, nickel electroplating is performed as a third metal film until the plurality of openings are closed. This step is referred to as a nozzle plate forming plating step.

Since the electrolytic plating has a feature of growing in all directions from the electrode to the space, the plating layer grows from the electrode on the bridge-like structure also in the in-plane direction of the silicon wafer to form a plurality of openings. Can be blocked. In the case of this embodiment, the width of the slit-shaped opening is set to 30 μm, so that the nickel plating layer as the third metal film has a thickness of 1 μm.
What is necessary is just to grow 5 micrometers or more.

Further, the nozzle hole whose opening area is expected to be larger than the opening does not close in the plating process for forming the nozzle plate. FIG. 6 (l) shows a state in which the opening is closed and the vibration transmission rod 21 has grown to an appropriate size.

Thereafter, the positive photosensitive resist 55 is removed, and after cleaning and surface treatment, a print head in which the desired nozzle plate 1, liquid chamber partition 3, vibration plate 5 and vibration transmission rod 21 are integrated is obtained. (FIG. 6 (m)).

At this time, the structure of the film of the diaphragm is a silicon nitride film, a chromium film, a gold film, and a nickel film when viewed from the liquid chamber side.

In this embodiment, the vibration transmission rod and the third metal film are formed simultaneously by electrolytic plating, but they may be formed separately as a matter of course. As one example of such a case, after forming the vibration plate 5, after protecting the surface B with a photosensitive resist, a second photosensitive resist is formed on the surface A, and a vibration transmission rod is formed by electrolytic plating. The anisotropic etching of the single crystal silicon wafer may be performed by removing the photosensitive resist.

Next, a process until a structure having a liquid chamber shape is obtained by a plurality of openings and points considered in designing a mask will be described with reference to FIGS. 19 and 20.

When a single crystal silicon wafer having a (110) plane on its surface is anisotropically etched,
The etching rate is significantly slower on the (111) plane than on the other planes. There are three (111) planes in the crystal in total, and two (111) planes are perpendicular to the silicon wafer surface.
There is one plane parallel to the <110> axis at an angle of 35.3 ° from the plane and the surface. In an etching opening closed inside like a circle or a square, basically six (11)
1) Etching is performed so as to be surrounded by the surface. FIG.
(A) is a top view showing the positional relationship between the (111) planes, and arrows X and Y in the figure represent two directions parallel to the (111) plane perpendicular to the paper surface. FIG. 19B is a perspective view of FIG. In the drawing, the liquid chamber designed parallel to the arrow X or Y is sandwiched between two (111) planes perpendicular to the paper surface, so that a deep groove shape can be obtained even in a narrow liquid chamber width. .

With such a rule, for example, FIG.
When anisotropic etching is performed using a rectangular opening PQRS having a width W parallel to the arrow X and a length H perpendicular to the arrow X as shown in FIG. , The dimensions and shape remain unchanged, and the (111) plane is formed perpendicular to the plane of the paper. However, the etching proceeds from the points P and R in parallel with the arrow Y to form a (111) plane parallel to the arrow Y. From points Q and S,
Etching proceeds in such a manner that a (111) plane existing parallel to the <110> axis is formed at a position inclined by 35.3 ° from the surface. Due to these actions, the etching proceeding from the points P and S intersects at the intersection T, and the etching proceeding from the points Q and R ends at the intersection U, and does not proceed any more than in the depth direction. Thus, the opening forms a hexagonal PQUARST with respect to the rectangular PQRS.

When two such openings are arranged in parallel along arrow X as shown in FIG. 20B, for example, if the distance D between the two rectangles is sufficiently long, two hexagons are formed at the end of etching. Square PQUARST and P'Q'U'R'S '
T ′ is formed, but this D is 0.354 ×
When the length is shorter than H, a state occurs in which the triangle QRU of the side-etched portion generated by the rectangle PQRS and the triangle P'S'T 'of the side-etched portion generated by the rectangle P'Q'R'S' overlap (FIG. 20). (C)). At this time, the intersection of the line segment QU and the line segment P'T 'is V, and the line segment RU and the line segment S'
Assuming that the intersection of T ′ is W, the angles QVP ′ and RWS ′ have a convex shape with respect to the space, and therefore the shapes are not maintained at the intersections V and W of the (111) planes (31).
3) An etched surface other than the (111) surface such as a surface appears,
The angle QVP 'and the angle RWS' are gradually etched, and finally disappear as shown in FIG.
Q'U'R'ST is formed.

By overlapping the side etches on both sides in this way, a larger area can be etched with a substantially smaller opening. At the same time, the bridge-like structure QR is placed on the hexagon PQ'U'R'ST.
You can also make S'P '. By arranging these in a large amount in the longitudinal direction of the liquid chamber as shown in FIG. 21 (a), a liquid chamber having a large area can be etched with a small opening, and at the same time, a number of bridge-like structures are formed on the liquid chamber. Can be left. By growing an electroplating layer on the basis of this bridge-like structure, a wide hollow structure can be obtained at the same time as forming the nozzle plate on the liquid chamber.

The size of the opening can theoretically be up to twice the thickness of the silicon wafer (300 μm in this embodiment) because the plating layer may be closed before the plating layer reaches the diaphragm. That is, the width of the opening is within twice (in this case, 6
With a design of (00 μm), a hollow structure can be obtained by the configuration of the present invention without using such a slit-shaped mask. However, this makes it difficult to form a nozzle hole, and the volume of available space is significantly reduced, which is not convenient. In a configuration like the present invention, the use of a slit-like pattern as shown in FIG. As a secondary effect, a weld line at the opening remains on the nozzle plate surface at the end of plating.
As shown in (1), it is also possible to form a line considering the flow of ink during maintenance of the nozzle plate.

In the above embodiment, the etching method is used when forming a plurality of openings in the second metal film. However, in the following embodiments, lift-off is performed to further improve the dimensional accuracy of the openings. An example in which the method is used will be described.

(Embodiment 4) FIGS. 7 and 8 show a simple manufacturing process diagram of a print head made by the present invention. (A)
-(L) represents the order of the steps. The process diagram is a cross-sectional view in which the liquid chamber portion of the print head is cut along the line XX ′ in FIG. In the single crystal silicon wafer, the side on which the diaphragm is formed is referred to as surface A, and the side on which a plurality of openings are formed is referred to as surface B. In the figure, the lower side is represented by surface A, and the upper side is represented by surface B.

First, both sides are polished to a thickness of about 300 μm.
A first metal film is formed on the entire surface A of the single crystal silicon wafer 7 having a crystal orientation of (110) by vacuum evaporation (FIG. 7A). The structure of the metal film is a chromium film 51 having a thickness of about 400 Å as an adhesion layer and a gold film 53 having a thickness of about 2,000 Å as a conductive layer and an etchant-resistant layer.

Next, a negative photosensitive resist 61 as a first photosensitive resist is applied to the entire surface B to a thickness of about 4 μm by a spin coater and prebaked with a hot plate or the like (FIG. 7 (b)). .

The surface B was exposed to ultraviolet light as shown in FIG. 7C using a quartz mask 57 on which a pattern as shown in FIG. 21A was drawn, and developed with a dedicated developer. When post-baking is performed after drying, the unexposed portions are lost and a pattern obtained by inverting the quartz mask is formed on the negative photosensitive resist 61 as shown in FIG.

Next, the surface B of the silicon wafer 7 is sufficiently ashed by oxygen plasma or the like, and a second metal film is formed by vacuum evaporation. Similar to the first metal film, the metal film includes a chromium film 51 having a thickness of about 400 Å as an adhesion layer and a gold film 53 having a thickness of about 2000 Å as a conductive layer and an etchant-resistant layer.

The second metal film is a negative photosensitive resist 61
Is thick enough to be separated into a second metal film attached to the surface of the negative photosensitive resist 61 and a second metal film attached to the surface of the silicon wafer 7 (FIG. 7).
(E)). When this is immersed in a dedicated stripping solution for the negative photosensitive resist 61 to dissolve the negative photosensitive resist 61, the silicon wafer 7 is formed on the silicon wafer 7 in the same manner as the quartz mask 57 to form a plurality of liquid chamber partition walls. Opening (FIG. 21)
21A, a second metal film having a nozzle hole (B in FIG. 21A) is formed, and the chromium film 51 and the gold film 53 on the negative photosensitive resist 61 are formed of a negative photosensitive film. It is peeled off together with the resist 61 (FIG. 7F).

In this embodiment, the structure of the metal film is made of chromium and gold for both the first metal film and the second metal film. However, it is possible to use titanium or platinum instead of chromium and nickel or platinum instead of gold. There is no problem in the invention. In addition, although the method of forming the metal film is also performed by vacuum deposition in this embodiment,
Instead, sputtering, CVD, plating, or the like may be used.

Here, after forming a first metal film on the surface A, a first photosensitive resist is formed, and then a second photosensitive resist is formed.
The formation of the metal film and the removal of the first photosensitive resist are performed. The first photosensitive resist is formed first, and then the first metal film and the second photosensitive resist are successively formed. Even if a metal film is formed, the structure does not change. However, in practice, in the step of forming the first photosensitive resist, the most dirt adheres to the single crystal silicon wafer. Therefore, selecting the latter step causes a reduction in yield and is not usually selected.

After a gold film 53 which is a part of the first metal film on the surface A is ashed sufficiently with oxygen plasma or the like to form a diaphragm film, the nickel film 5 is used as an electrode.
9 is grown by electrolytic plating to a thickness of about 5 μm. This step is referred to as a diaphragm forming plating step, and nickel is simultaneously grown on the surface B. As a result, the result is as shown in FIG.

Since the specific resistance of silicon differs greatly from that of gold, most of the nickel film 59 grows on the gold film 53 and does not grow on the silicon wafer 7 during the electrolytic plating step. It does not affect dimensional accuracy.

At this time, the surface B may be protected by a photosensitive resist or the like so that nickel does not grow. However, the second metal film has a very small thickness of about 2400 angstroms at this time. When performing anisotropic etching of the silicon wafer 7 using the second metal film as a second mask in the process, a part of the second metal film is broken by a generated hydrogen gas or the like, or is deformed by stress. It is also possible. Since the second metal film plays an important role in forming the nozzle plate in the present invention, it is necessary to grow the nickel film 59 on the second metal film at the same time as forming the diaphragm as in this embodiment. Can supplement the strength and improve the dimensional accuracy.

In this embodiment, nickel is used as the diaphragm by electrolytic plating, but the material may be gold, platinum, etc. as long as the diaphragm has rigidity and resistance to the etchant of anisotropic etching. Also available. Also, the forming method is not limited to the electrolytic plating method, but also includes sputtering and CVD.
Also available.

The silicon wafer 7 having undergone the above steps is 3
When immersed in a 0 wt% aqueous solution of potassium hydroxide at about 70 ° C., silicon starts to be etched anisotropically from the nozzle hole and the plurality of openings (FIG. 7 (h)).
At this time, as shown in FIG. 21A, the plurality of openings have a structure in which a plurality of slit-like patterns each having a width of about 30 μm are arranged in parallel, and a process in which side etching proceeds from these openings. Spaces communicate with each other in
Finally, the desired liquid chamber partition wall, diaphragm and liquid chamber of the print head are obtained.

At this time, since the nickel film 59 has a strong resistance to the aqueous solution of potassium hydroxide, it does not erode without special protection.

FIG. 7 (i) shows the state when the anisotropic etching reaches the chromium film 51. When the anisotropic etching proceeds from the plurality of slit-shaped openings and penetrates the silicon wafer, the surface of the diaphragm seen from the liquid chamber 6 side looks like a chromium film 51 previously applied. Similarly, the side where the bridge-like structure, which is a part of the second metal film remaining on the surface B side, faces the liquid chamber 6, also has the chromium film 51. When the chromium film 51 is subjected to surface treatment in an atmosphere in which ozone is generated by irradiating ultraviolet rays to the atmosphere, a chromium oxide layer is obtained on the surface.

If the chromium film 51 is opened on the surface of the diaphragm viewed from the liquid chamber 6 at the time of electrolytic plating in the next step, nickel plating may grow there. It plays a role to avoid.

Here, an ultraviolet irradiation type ozone washing machine is used to obtain a chromium oxide layer, but other methods such as heat treatment in an oxygen atmosphere or oxygen plasma treatment under a low pressure are used. The method is conceivable.

Next, a positive photosensitive resist 55 is applied as a second photosensitive resist to a thickness of about 5 μm as a second photosensitive resist on a surface of the vibration plate by a bar coater or the like, and is exposed and developed to form a pattern of a vibration transmission rod ( FIG. 8 (j)).

Thereafter, the nickel film 59 adhered to the surface of the second metal film when the diaphragm film was formed was used as an electrode.
Further, nickel electroplating is performed as a third metal film until the plurality of openings are closed. This step is referred to as a nozzle plate forming plating step.

Since the electroplating has a feature of growing in all directions from the electrode to the space, the plating layer grows from the electrode on the bridge-like structure also in the in-plane direction of the silicon wafer to form a plurality of openings. Can be blocked. In the case of this embodiment, the width of the slit-shaped opening is set to 30 μm, so that the nickel plating layer as the third metal film has a thickness of 1 μm.
What is necessary is just to grow 5 micrometers or more.

Further, the nozzle hole which is expected to have a larger opening area than the opening is not closed in the plating process for forming the nozzle plate. FIG. 8 (k) shows a state in which the opening is closed and the vibration transmission rod 21 has grown to an appropriate size.

Thereafter, the positive photosensitive resist 55 is removed, and after cleaning and surface treatment, a print head in which the desired nozzle plate 1, liquid chamber partition 3, vibration plate 5, and vibration transmission rod 21 are integrated is obtained. (FIG. 8 (l)).

At this time, the structure of the diaphragm film is a chromium film, a gold film, and a nickel film when viewed from the liquid chamber side.

In this embodiment, the vibration transmission rod and the third metal film are formed simultaneously by electrolytic plating, but they may be formed separately as a matter of course. As one example of such a case, after forming the vibration plate 5, after protecting the surface B with a photosensitive resist, a second photosensitive resist is formed on the surface A, and a vibration transmission rod is formed by electrolytic plating. The anisotropic etching of the single crystal silicon wafer may be performed by removing the photosensitive resist.

(Embodiment 5) FIGS. 9 and 10 show a simple manufacturing process diagram of a print head made by the present invention.
(A) to (l) indicate the order of the steps. The process diagram is shown in FIG.
FIG. 3A is a cross-sectional view of the print head taken along a line XX ′ in FIG. In the single crystal silicon wafer, the side on which the diaphragm is formed is referred to as surface A, and the side on which a plurality of openings are formed is referred to as surface B. In the figure, the lower side is surface A,
The upper side is represented by surface B.

First, both sides are polished to a thickness of about 300 μm.
A first metal film is formed on the entire surface A of the single crystal silicon wafer 7 having a crystal orientation of (110) by vacuum evaporation (FIG. 9A). The structure of the metal film is a chromium film 51 having a thickness of about 400 Å as an adhesion layer and a gold film 53 having a thickness of about 2,000 Å as a conductive layer and an etchant-resistant layer.

Next, a negative photosensitive resist 61 as a first photosensitive resist is applied to the entire surface B to a thickness of about 4 μm by a spin coater, and prebaked with a hot plate or the like (FIG. 9B). .

The surface B was exposed to ultraviolet light as shown in FIG. 9C using a quartz mask 57 on which a pattern as shown in FIG. 21A was drawn, and developed with a dedicated developer. When post-baking is performed after drying, the unexposed portions are dissolved away, and a pattern obtained by inverting the quartz mask is formed on the negative photosensitive resist 61 as shown in FIG.

Next, the surface B of the silicon wafer 7 is sufficiently ashed by oxygen plasma or the like, and a second metal film is formed by vacuum evaporation. Similar to the first metal film, the metal film includes a chromium film 51 having a thickness of about 400 Å as an adhesion layer and a gold film 53 having a thickness of about 2000 Å as a conductive layer and an etchant-resistant layer.

The second metal film is a negative photosensitive resist 61
9 is separated into a second metal film attached to the surface of the negative photosensitive resist 61 and a second metal film attached to the surface of the silicon wafer 7 (FIG. 9).
(E)). When this is immersed in a dedicated stripping solution for the negative photosensitive resist 61 to dissolve the negative photosensitive resist 61, the silicon wafer 7 is formed on the silicon wafer 7 in the same manner as the quartz mask 57 to form a plurality of liquid chamber partition walls. Opening (FIG. 21)
21A, a second metal film having a nozzle hole (B in FIG. 21A) is formed, and the chromium film 51 and the gold film 53 on the negative photosensitive resist 61 are formed of a negative photosensitive film. It is peeled off together with the resist 61 (FIG. 9F).

In this embodiment, the structure of the metal film is made of chromium and gold for both the first metal film and the second metal film. However, it is possible to use titanium or platinum instead of chromium and nickel or platinum instead of gold. There is no problem in the invention. In addition, although the method of forming the metal film is also performed by vacuum deposition in this embodiment,
Instead, sputtering, CVD, plating, or the like may be used.

Here, after forming the first metal film on the surface A, the first photosensitive resist is formed, and then the second photosensitive resist is formed.
The formation of the metal film and the removal of the first photosensitive resist are performed. The first photosensitive resist is formed first, and then the first metal film and the second photosensitive resist are successively formed. Even if a metal film is formed, the structure does not change. However, in practice, in the step of forming the first photosensitive resist, the most dirt adheres to the single crystal silicon wafer. Therefore, selecting the latter step causes a reduction in yield and is not usually selected.

After the gold film 53, which is a part of the first metal film on the surface A, is sufficiently ashed with oxygen plasma or the like to form a diaphragm film, the nickel film 5 is used as an electrode.
9 is grown by electrolytic plating to a thickness of about 5 μm. This step is a plating step for forming a diaphragm, and nickel also grows on the surface B at the same time. As a result, the result is as shown in FIG.

Since the specific resistance values of silicon and gold are greatly different, the nickel film 59 mostly grows on the gold film 53 during the electrolytic plating step, and does not grow on the silicon wafer 7. It does not affect dimensional accuracy.

At this time, the surface B may be protected by a photosensitive resist or the like so that nickel does not grow. However, since the second metal film has a very small thickness of about 2400 angstroms, When performing anisotropic etching of the silicon wafer 7 using the second metal film as a second mask in the process, a part of the second metal film is broken by a generated hydrogen gas or the like, or is deformed by stress. It is also possible. Since the second metal film plays an important role in forming the nozzle plate in the present invention, it is necessary to grow the nickel film 59 on the second metal film at the same time as forming the diaphragm as in this embodiment. Can supplement the strength and improve the dimensional accuracy.

In this embodiment, nickel is used as the diaphragm by electrolytic plating. However, the material may be gold, platinum or the like, as long as the diaphragm has rigidity and resistance to anisotropic etching etchant. Also available. Also, the forming method is not limited to the electrolytic plating method, but also includes sputtering and CVD.
Also available.

The silicon wafer 7 having undergone the above steps is 3
When immersed in a 0 wt% aqueous solution of potassium hydroxide at about 70 ° C., silicon starts to be etched anisotropically from the nozzle hole and the plurality of openings (FIG. 9H).
At this time, as shown in FIG. 21A, the plurality of openings have a structure in which a plurality of slit-like patterns each having a width of about 30 μm are arranged in parallel, and a process in which side etching proceeds from these openings. Spaces communicate with each other in
Finally, the desired liquid chamber partition wall, diaphragm and liquid chamber of the print head are obtained.

At this time, since the nickel film 59 has a strong resistance to the aqueous solution of potassium hydroxide, it does not erode without special protection.

Here, in this embodiment, once the anisotropic etching is interrupted, silicon is left several μm as viewed from the diaphragm. The state so far is shown in FIG.

This is because if the first metal film is opened on the surface of the diaphragm seen from the liquid chamber 6 at the time of electrolytic plating in the next step, nickel plating may grow there. The role is to avoid.

Next, a positive photosensitive resist 55 as a second photosensitive resist is applied to the surface of the diaphragm to a thickness of about 5 μm with a bar coater or the like, and is exposed and developed to form a pattern of a vibration transmitting rod ( FIG. 10 (j)).

Thereafter, the nickel film 59 adhered to the surface of the second metal film when the diaphragm film was formed was used as an electrode.
Further, nickel electroplating is performed as a third metal film until the plurality of openings are closed. This step is referred to as a nozzle plate forming plating step.

Since the electroplating has a feature of growing in all directions with respect to the space from the electrode, the plating layer grows from the electrode on the bridge-like structure also in the in-plane direction of the silicon wafer to form a plurality of openings. Can be blocked. In the case of this embodiment, the width of the slit-shaped opening is set to 30 μm, so that the nickel plating layer as the third metal film has a thickness of 1 μm.
What is necessary is just to grow 5 micrometers or more.

Further, the nozzle hole which is expected to have a larger opening area than the opening does not close in this nozzle plate forming plating step. FIG. 10 (k) shows a state where the opening is closed and the vibration transmission rod 21 has grown to an appropriate size.

Thereafter, after removing the positive photosensitive resist 55, washing and surface treatment are performed to obtain the desired nozzle plate 1,
A print head in which the liquid chamber partition 3, the vibration plate 5, and the vibration transmission rod 21 are integrated is obtained (FIG. 10 (l)).

At this time, the structure of the film of the diaphragm is a silicon, chromium film, gold film and nickel film when viewed from the liquid chamber side. If the silicon portion does not have an appropriate thickness as a diaphragm, the positive photosensitive resist 55 is removed, and then the silicon wafer is again subjected to anisotropic etching with a potassium hydroxide aqueous solution.

In this embodiment, the vibration transmission rod and the third metal film are formed simultaneously by electrolytic plating, but may be formed separately. As one example of such a case, after forming the vibration plate 5, after protecting the surface B with a photosensitive resist, a second photosensitive resist is formed on the surface A, and a vibration transmission rod is formed by electrolytic plating. The anisotropic etching of the single crystal silicon wafer may be performed by removing the photosensitive resist.

(Embodiment 6) FIGS. 11 and 12 show a simple manufacturing process diagram of a print head made by the present invention.
(A) to (l) indicate the order of the steps. The process diagram is shown in FIG.
FIG. 3A is a cross-sectional view of the print head taken along a line XX ′ in FIG. In the single crystal silicon wafer, the side on which the diaphragm is formed is referred to as surface A, and the side on which a plurality of openings are formed is referred to as surface B. In the figure, the lower side is surface A,
The upper side is represented by surface B.

First, both sides are polished to a thickness of about 300 μm.
A silicon nitride film 63 having a thickness of 1000 angstroms is formed on the entire surface A of the single crystal silicon wafer 7 having a crystal orientation of (110) by a CVD method or the like (FIG. 1).
1 (a)). A first metal film is further formed thereon by vacuum evaporation. The structure of the metal film is about 4
A chromium film 51 having a thickness of 00 Å and a gold film 53 having a thickness of about 2000 Å as a conductive layer and an etchant-resistant layer.

Next, a negative photosensitive resist 61 as a first photosensitive resist is applied to the entire surface B to a thickness of about 4 μm by a spin coater, and prebaked with a hot plate or the like (FIG. 11B). .

The surface B is exposed to ultraviolet light using a quartz mask 57 on which a pattern as shown in FIG. 21A is drawn as shown in FIG. When post-baking is performed after drying, the unexposed portions are lost and a pattern obtained by inverting the quartz mask is formed on the negative photosensitive resist 61 as shown in FIG.

Next, the surface B of the silicon wafer 7 is sufficiently ashed by oxygen plasma or the like, and a second metal film is formed by vacuum evaporation. Similar to the first metal film, the metal film includes a chromium film 51 having a thickness of about 400 Å as an adhesion layer and a gold film 53 having a thickness of about 2000 Å as a conductive layer and an etchant-resistant layer.

The second metal film is a negative photosensitive resist 61
Is sufficiently thick, it is separated into a second metal film attached to the surface of the negative photosensitive resist 61 and a second metal film attached to the surface of the silicon wafer 7 (FIG. 11).
(E)). When this is immersed in a dedicated stripping solution for the negative photosensitive resist 61 to dissolve the negative photosensitive resist 61, the silicon wafer 7 is formed on the silicon wafer 7 in the same manner as the quartz mask 57 to form a plurality of liquid chamber partition walls. Opening (FIG. 21)
21A, a second metal film having a nozzle hole (B in FIG. 21A) is formed, and the chromium film 51 and the gold film 53 on the negative photosensitive resist 61 are formed of a negative photosensitive film. It is peeled off together with the resist 61 (FIG. 11F).

In this embodiment, the metal film is composed of chromium and gold for both the first metal film and the second metal film. However, it is also possible to use titanium or platinum instead of chromium and nickel or platinum instead of gold. There is no problem in the invention. In addition, although the method of forming the metal film is also performed by vacuum deposition in this embodiment,
Instead, sputtering, CVD, plating, or the like may be used.

Here, after forming a first metal film on the surface A, a first photosensitive resist is formed, and then a second photosensitive resist is formed.
The formation of the metal film and the removal of the first photosensitive resist are performed. The first photosensitive resist is formed first, and then the first metal film and the second photosensitive resist are successively formed. Even if a metal film is formed, the structure does not change. However, in practice, in the step of forming the first photosensitive resist, the most dirt adheres to the single crystal silicon wafer. Therefore, selecting the latter step causes a reduction in yield and is not usually selected.

After a gold film 53, which is a part of the first metal film on the surface A, is sufficiently ashed with oxygen plasma or the like to form a diaphragm film, the nickel film 5 is used as an electrode.
9 is grown by electrolytic plating to a thickness of about 5 μm. This step is a diaphragm forming plating step, and nickel is simultaneously grown on the surface B. As a result, the result is as shown in FIG.

Since the specific resistance values of silicon and gold are greatly different, the nickel film 59 mostly grows on the gold film 53 during the electrolytic plating step, and does not grow on the silicon wafer 7. It does not affect dimensional accuracy.

At this time, the surface B may be protected by a photosensitive resist or the like so that nickel does not grow. However, the second metal film has a very small thickness of about 2400 angstroms at this time. When performing anisotropic etching of the silicon wafer 7 using the second metal film as a second mask in the process, a part of the second metal film is broken by a generated hydrogen gas or the like, or is deformed by stress. It is also possible. Since the second metal film plays an important role in forming the nozzle plate in the present invention, it is necessary to grow the nickel film 59 on the second metal film at the same time as forming the diaphragm as in this embodiment. Can supplement the strength and improve the dimensional accuracy.

In this embodiment, the diaphragm is formed by electrolytic plating using nickel as the diaphragm, but other materials such as gold and platinum may be used as long as the diaphragm has rigidity and resistance to the etchant of anisotropic etching. Also available. Also, the forming method is not limited to the electrolytic plating method, but also includes sputtering and CVD.
Also available.

In this embodiment, since the silicon nitride film exists, the thickness of nickel is adjusted in consideration of the rigidity of the diaphragm. In this case, the thickness of the silicon nitride is 100
Although it is 0 angstroms, when this is about 1 μm, nickel may not be particularly necessary in some cases. At this time,
The vibration plate forming plating step is a step for forming nickel on the second metal film.

The silicon wafer 7 having undergone the above steps is 3
When immersed in a 0 wt% aqueous potassium hydroxide solution at about 70 ° C., silicon starts to be etched anisotropically through the nozzle hole and the plurality of openings (FIG. 11).
(H)). At this time, a plurality of openings are formed as shown in FIG.
As shown in (a), a plurality of slit-like patterns each having a width of about 30 μm are arranged in parallel, and spaces are communicated with each other in the process of side etching from these openings, and finally, The required liquid chamber partition, diaphragm and liquid chamber of the print head are obtained.

At this time, since the nickel film 59 has a strong resistance to an aqueous solution of potassium hydroxide, it does not erode without special protection.

FIG. 11I shows the state when the anisotropic etching reaches the silicon nitride film 63. When the anisotropic etching proceeds from the plurality of slit-shaped openings and penetrates the silicon wafer, the surface of the vibration plate viewed from the liquid chamber 6 side becomes the silicon nitride film 63 previously formed.
Appears.

If the first metal film is opened on the surface of the diaphragm viewed from the liquid chamber 6 at the time of electrolytic plating in the next step, nickel plating may grow there. The role is to avoid this.

Next, a positive photosensitive resist 55 as a second photosensitive resist is applied to the surface of the diaphragm to a thickness of about 5 μm with a bar coater or the like, and is exposed and developed to form a pattern of a vibration transmission rod ( FIG. 12 (j).

Thereafter, the nickel film 59 adhered to the surface of the second metal film when the diaphragm film was formed was used as an electrode.
Further, nickel electroplating is performed as a third metal film until the plurality of openings are closed. This step is referred to as a nozzle plate forming plating step.

[0186] Since electrolytic plating has a feature of growing in all directions from the electrode to the space, the plating layer grows from the electrode on the bridge-like structure also in the in-plane direction of the silicon wafer to form a plurality of openings. Can be blocked. In the case of this embodiment, the width of the slit-shaped opening is set to 30 μm, so that the nickel plating layer as the third metal film has a thickness of 1 μm.
What is necessary is just to grow 5 micrometers or more.

The nozzle hole which is expected to have a larger opening area than the opening does not close in the nozzle plate forming plating step. FIG. 12 (k) shows a state in which the opening is closed and the vibration transmission rod 21 has grown to an appropriate size.

After that, the positive photosensitive resist 55 is removed, and after cleaning and surface treatment, a print head in which the desired nozzle plate 1, liquid chamber partition 3, vibration plate 5, and vibration transmission rod 21 are integrated is obtained. (FIG. 12 (l)).

At this time, the structure of the film of the diaphragm is a silicon nitride film, a chromium film, a gold film, and a nickel film when viewed from the liquid chamber side.

In this embodiment, the vibration transmission rod and the third metal film are formed simultaneously by electrolytic plating, but they may be formed separately as a matter of course. As one example of such a case, after forming the vibration plate 5, after protecting the surface B with a photosensitive resist, a second photosensitive resist is formed on the surface A, and a vibration transmission rod is formed by electrolytic plating. The anisotropic etching of the single crystal silicon wafer may be performed by removing the photosensitive resist.

In the above embodiments, the lift-off method is used when forming a plurality of openings in the second metal film. However, in the following embodiments, a plurality of openings are formed in order to further improve the dimensional accuracy of the openings. Surface B forming an opening composed of individual pieces
An example in which a silicon nitride film is formed to improve the adhesion to silicon and an opening is formed by dry etching. At this time, a silicon nitride film as a second mask and a second metal film as an electrode for forming a third metal film are present on the surface B, and the sizes of the openings of both are adjusted. Thus, the step accuracy of the nozzle hole can be dramatically improved.

(Embodiment 7) FIGS. 13 and 14 show simple manufacturing process diagrams of a print head made by the present invention.
(A) to (r) indicate the order of the steps. The process diagram is shown in FIG.
FIG. 3A is a cross-sectional view of the print head taken along a line XX ′ in FIG. In the single crystal silicon wafer, the side on which the diaphragm is formed is referred to as surface A, and the side on which a plurality of openings are formed is referred to as surface B. In the figure, the lower side is surface A,
The upper side is represented by surface B.

First, both sides are polished to a thickness of about 300 μm.
A silicon nitride film 63 having a thickness of 1000 angstroms is formed on the entire surface B of the single crystal silicon wafer 7 having a crystal orientation of (110) by CVD or the like (FIG. 1).
3 (a)).

Further, a first metal film is formed on the surface A and a second metal film is formed on the surface B by vacuum evaporation (FIG. 13B). Each of the metal films is composed of a chromium film 51 having a thickness of about 400 Å as an adhesion layer and a gold film 53 having a thickness of about 2000 Å as a conductive layer and an etchant-resistant layer.

In this embodiment, the structure of the metal film is made of chromium and gold for both the first metal film and the second metal film. However, it is possible to use titanium or platinum instead of chromium and nickel or platinum instead of gold. There is no problem in the invention. In addition, although the method of forming the metal film is also performed by vacuum deposition in this embodiment,
Instead, sputtering, CVD, plating, or the like may be used.

Next, a positive photosensitive resist 55 as a first photosensitive resist is applied to the entire surface B to a thickness of about 2 μm by a spin coater, and prebaked using a hot plate or the like. Similarly, FIG.
(C).

The surface B was exposed to ultraviolet light as shown in FIG. 13D using a quartz mask 57 on which a pattern as shown in FIG. 21A was drawn, and developed with a dedicated developer. When post-baking is performed after drying, the exposed portions are dissolved and a pattern similar to that of the quartz mask is formed on the positive photosensitive resist 55 as shown in FIG.

Here, the positive photosensitive resist 55 on the surface A is used.
Was formed as a protective film for protecting the gold film 53 from an etchant in the next step.

Next, using the exposed and developed positive photosensitive resist 55 as a first mask, the gold film 53 is etched with aqua regia (mixed solution of nitric acid and hydrochloric acid, mixing ratio of 1: 1 to 1: 3). . Further, the chromium film 51 is coated with a mixed aqueous solution of cerium ammonium nitrate and perchloric acid (for example, 20 g of cerium ammonium nitrate and 20 ml of perchloric acid per 1 L of pure water).
The gold film 53 and the chromium film 5
1 is patterned into the same shape as the positive photosensitive resist 55, and a plurality of openings (A in FIG. 21 (a)) and nozzle holes (FIG. 21 (a)) for forming liquid chamber partitions are formed.
B) is formed on the surface B as shown in FIG. After the patterning of the chromium film and the gold film, the positive photosensitive resist 55 is removed with a dedicated stripper for the next step, and the shape becomes as shown in FIG. 13 (g).

Here, a plurality of openings are formed in the second metal film by wet etching, but sputter etching or reactive ion etching may be used.

Next, as a third photosensitive resist, a positive photosensitive resist 55 is again applied to the entire surface B to a thickness of about 2 μm by a spin coater, and prebaked with a hot plate or the like (FIG. 13 (h)). ).

The surface B is similarly exposed to ultraviolet light as shown in FIG. 13 (i) using the quartz mask 57 having the nozzle hole designed to have a slightly smaller diameter than the quartz mask 57 described above. When post-baking is performed after development and drying with a liquid, the exposed portions are dissolved and a pattern similar to a quartz mask is formed on the positive photosensitive resist 55 as shown in FIG.

Next, the silicon nitride film 63 is etched with a dry etching apparatus using the exposed and developed positive photosensitive resist 55 as a third mask, so that the silicon nitride film 63 has the same shape as the third mask. A plurality of openings and nozzle holes for patterning and forming a liquid chamber partition are formed on the surface B as shown in FIG. After the patterning of the silicon nitride film 63, the positive photosensitive resist 55 is removed with a dedicated stripping solution for the next step, and the shape becomes as shown in FIG.

Here, a plurality of openings are formed in the silicon nitride film 63 by dry etching. However, the openings cannot be formed by wet etching using a mixed aqueous solution of hydrofluoric acid and nitric acid. It is possible. In this case, the dimensional accuracy is slightly lower than in the case of dry etching.

After a gold film 53 which is a part of the first metal film on the surface A is ashed sufficiently with oxygen plasma or the like to form a diaphragm film, the nickel film 5 is used as an electrode.
9 is grown by electrolytic plating to a thickness of about 5 μm. This stage is a diaphragm forming plating process, and nickel is simultaneously grown on the surface B. As a result, the result is as shown in FIG.

Since the specific resistance values of silicon and gold are greatly different from each other, during the electrolytic plating step, most of the nickel film 59 grows on the gold film 53 and does not grow on the silicon wafer 7 or the silicon nitride film 63. There is no influence on the dimensional accuracy of the gold film 53 thus obtained.

At this time, the surface B may be protected with a photosensitive resist or the like so that nickel does not grow.

In this embodiment, the diaphragm is formed by electrolytic plating using nickel as the diaphragm. However, other materials such as gold and platinum may be used as long as the diaphragm has rigidity and resistance to the etchant of anisotropic etching. Also available. Also, the forming method is not limited to the electrolytic plating method, but also includes sputtering and CVD.
Also available.

The silicon wafer 7 having undergone the above steps is 3
When immersed in a 0 wt% aqueous solution of potassium hydroxide at about 70 ° C., silicon starts to be etched anisotropically from the nozzle hole and the opening formed of a plurality (FIG. 14).
(N)). At this time, a plurality of openings are formed as shown in FIG.
As shown in (a), a plurality of slit-like patterns each having a width of about 30 μm are arranged in parallel, and spaces are communicated with each other in the process of side etching from these openings, and finally, The required liquid chamber partition, diaphragm and liquid chamber of the print head are obtained.

At this time, since the nickel film 59 has a strong resistance to the aqueous solution of potassium hydroxide, it does not erode without special protection.

FIG. 14 (o) shows a state when the anisotropic etching reaches the chromium film 51. When the anisotropic etching proceeds from the plurality of slit-shaped openings and penetrates the silicon wafer, the surface of the diaphragm seen from the liquid chamber 6 side looks like a chromium film 51 previously applied. Similarly, the side where the bridge-like structure, which is a part of the second metal film remaining on the surface B side, faces the liquid chamber 6, also has the chromium film 51. When the chromium film 51 is subjected to surface treatment in an atmosphere in which ozone is generated by irradiating ultraviolet rays to the atmosphere, a chromium oxide layer is obtained on the surface.

This is because if the chromium film 51 is opened on the surface of the diaphragm viewed from the liquid chamber 6 at the time of electrolytic plating in the next step, nickel plating may grow there, and this is avoided. Play a role.

Here, an ultraviolet irradiation type ozone washing machine is used to obtain a chromium oxide layer, but other methods such as heat treatment in an oxygen atmosphere or oxygen plasma treatment under a low pressure are used. The method is conceivable.

Next, a positive photosensitive resist 55 is applied as a second photosensitive resist on the surface of the vibration plate to a thickness of about 5 μm with a bar coater or the like, and is exposed and developed to form a pattern of a vibration transmission rod ( FIG. 14 (p)).

Thereafter, the nickel film 59 adhered to the surface of the second metal film when the diaphragm film was formed was used as an electrode.
Further, nickel electroplating is performed as a third metal film until the plurality of openings are closed. This step is referred to as a nozzle plate forming plating step.

Since the electrolytic plating has a feature of growing in all directions from the electrode to the space, the plating layer grows from the electrode on the bridge-like structure also in the in-plane direction of the silicon wafer to form a plurality of openings. Can be blocked. In the case of this embodiment, the width of the slit-shaped opening is set to 30 μm, so that the nickel plating layer as the third metal film has a thickness of 1 μm.
What is necessary is just to grow 5 micrometers or more.

Further, the nozzle hole whose opening area is expected to be larger than the opening does not close in the nozzle plate forming plating step. Further, in the present embodiment, since the nozzle hole diameters of the second metal film and the silicon nitride film are different from each other, it is possible to minimize the wraparound of the nickel plating layer in the nozzle hole portion. That is, since the silicon nitride film is insulative, no plating layer is formed thereon, and only the growth from the gold film is performed, so that the size and shape of the nozzle hole can be easily controlled.
FIG. 14 (q) shows a state in which the opening is closed and the vibration transmission rod 21 has grown to an appropriate size.

Thereafter, the positive photosensitive resist 55 is removed, and after cleaning and surface treatment, a print head in which the desired nozzle plate 1, liquid chamber partition 3, vibration plate 5, and vibration transmission rod 21 are integrated is obtained. (FIG. 14 (r)).

At this time, the structure of the film of the diaphragm is a chromium film, a gold film, and a nickel film when viewed from the liquid chamber side.

In the present embodiment, the vibration transmission rod and the third metal film are formed simultaneously by electrolytic plating, but they may be formed separately as a matter of course. As one example of such a case, after forming the vibration plate 5, after protecting the surface B with a photosensitive resist, a second photosensitive resist is formed on the surface A, and a vibration transmission rod is formed by electrolytic plating. The anisotropic etching of the single crystal silicon wafer may be performed by removing the photosensitive resist.

(Embodiment 8) FIGS. 15 and 16 show a simple manufacturing process diagram of a print head manufactured by the present invention.
(A) to (r) indicate the order of the steps. The process diagram is shown in FIG.
FIG. 3A is a cross-sectional view of the print head taken along a line XX ′ in FIG. In the single crystal silicon wafer, the side on which the diaphragm is formed is referred to as surface A, and the side on which a plurality of openings are formed is referred to as surface B. In the figure, the lower side is surface A,
The upper side is represented by surface B.

First, both sides are polished to a thickness of about 300 μm.
A silicon nitride film 63 having a thickness of 1000 angstroms is formed on the entire surface B of the single crystal silicon wafer 7 having a crystal orientation of (110) by CVD or the like (FIG. 1).
5 (a)).

Further, a first metal film is formed on the surface A and a second metal film is formed on the surface B by vacuum evaporation (FIG. 15B). Each of the metal films is composed of a chromium film 51 having a thickness of about 400 Å as an adhesion layer and a gold film 53 having a thickness of about 2000 Å as a conductive layer and an etchant-resistant layer.

In this embodiment, the structure of the metal film is made of chromium and gold for both the first metal film and the second metal film. However, it is possible to use titanium or platinum instead of chromium and nickel or platinum instead of gold. There is no problem in the invention. In addition, although the method of forming the metal film is also performed by vacuum deposition in this embodiment,
Instead, sputtering, CVD, plating, or the like may be used.

Next, a positive photosensitive resist 55 as a first photosensitive resist is applied to the entire surface of the surface B to a thickness of about 2 μm by a spin coater, and prebaked by a hot plate or the like. FIG. 15 shows the results obtained for the surface A in the same manner.
(C).

The surface B was exposed to ultraviolet light as shown in FIG. 15D using a quartz mask 57 on which a pattern as shown in FIG. 21A was drawn, and developed with a dedicated developer. When post-baking is performed after drying, the exposed portions are dissolved away, and a pattern similar to a quartz mask is formed on the positive photosensitive resist 55 as shown in FIG.

Here, the positive photosensitive resist 55 on the surface A is used.
Was formed as a protective film for protecting the gold film 53 from an etchant in the next step.

Next, using the exposed and developed positive photosensitive resist 55 as a first mask, the gold film 53 is etched with aqua regia (mixed solution of nitric acid and hydrochloric acid, mixing ratio of 1: 1 to 1: 3). . Further, the chromium film 51 is coated with a mixed aqueous solution of cerium ammonium nitrate and perchloric acid (for example, 20 g of cerium ammonium nitrate and 20 ml of perchloric acid per 1 L of pure water).
The gold film 53 and the chromium film 5
1 is patterned into the same shape as the positive photosensitive resist 55, and a plurality of openings (A in FIG. 21 (a)) and nozzle holes (FIG. 21 (a)) for forming liquid chamber partitions are formed.
B) is formed on the surface B as shown in FIG. After the patterning of the chromium film and the gold film, the positive photosensitive resist 55 is removed by a dedicated stripper for the next step, and the shape becomes as shown in FIG.

Here, a plurality of openings are formed in the second metal film by wet etching, but sputter etching or reactive ion etching may be used.

Next, a positive photosensitive resist 55 is applied as a third photosensitive resist to a thickness of about 2 μm again on the entire surface of the surface B by a spin coater, and prebaked with a hot plate or the like (FIG. 15 (h)). ).

The surface B was similarly exposed to ultraviolet light as shown in FIG. 15 (i) using the quartz mask 57 having the nozzle hole designed to have a slightly smaller diameter than the quartz mask 57 described above. When post-baking is performed through development and drying with a liquid, the exposed portions are dissolved and a pattern similar to a quartz mask is formed on the positive photosensitive resist 55 as shown in FIG.

Next, the silicon nitride film 63 is etched with a dry etching apparatus using the exposed and developed positive photosensitive resist 55 as a third mask, so that the silicon nitride film 63 has the same shape as the third mask. A plurality of openings and nozzle holes for patterning and forming a liquid chamber partition are formed on the surface B as shown in FIG. After the patterning of the silicon nitride film 63, the positive photosensitive resist 55 is removed by a dedicated stripping solution for the next step, and the shape becomes as shown in FIG.

Here, a plurality of openings are formed in the silicon nitride film 63 by dry etching. However, the openings may not be formed by wet etching using a mixed aqueous solution of hydrofluoric acid and nitric acid. It is possible. In this case, the dimensional accuracy is slightly lower than in the case of dry etching.

After a gold film 53, which is a part of the first metal film on the surface A, is sufficiently ashed with oxygen plasma or the like to form a diaphragm film, the nickel film 5 is used as an electrode.
9 is grown by electrolytic plating to a thickness of about 5 μm. This step is a diaphragm forming plating step, and nickel is simultaneously grown on the surface B. As a result, the result is as shown in FIG.

Since the specific resistance values of silicon and gold are significantly different, the nickel film 59 is mostly grown on the gold film 53 during the electrolytic plating step, but is not grown on the silicon wafer 7 or the silicon nitride film 63. The dimensional accuracy of the deposited gold film 53 is not affected.

At this time, the surface B may be protected with a photosensitive resist or the like so that nickel does not grow.

In this embodiment, the diaphragm is formed by electrolytic plating using nickel as the diaphragm. However, other materials such as gold and platinum may be used as long as the diaphragm has rigidity and resistance to the etchant of anisotropic etching. Also available. Also, the forming method is not limited to the electrolytic plating method, but also includes sputtering and CVD.
Also available.

The silicon wafer 7 having undergone the above steps is 3
When immersed in a 0 wt% aqueous potassium hydroxide solution at about 70 ° C., silicon begins to be anisotropically etched through the nozzle hole and the plurality of openings (FIG. 16).
(N)). At this time, a plurality of openings are formed as shown in FIG.
As shown in (a), a plurality of slit-like patterns each having a width of about 30 μm are arranged in parallel, and spaces are communicated with each other in the process of side etching from these openings, and finally, The required liquid chamber partition, diaphragm and liquid chamber of the print head are obtained.

At this time, since the nickel film 59 has a strong resistance to the aqueous solution of potassium hydroxide, it does not erode without special protection.

Here, in this embodiment, the anisotropic etching is interrupted once, and silicon is left several μm as viewed from the diaphragm. The state so far is shown in FIG.

This is because if the first metal film is opened on the surface of the diaphragm viewed from the liquid chamber 6 at the time of electrolytic plating in the next step, nickel plating may grow there. The role is to avoid.

Next, a positive photosensitive resist 55 is applied as a second photosensitive resist on the surface of the diaphragm to a thickness of about 5 μm with a bar coater or the like, and is exposed and developed to form a pattern of a vibration transmission rod ( FIG. 16 (p)).

Thereafter, the nickel film 59 adhered to the surface of the second metal film when the diaphragm film was formed was used as an electrode.
Further, nickel electroplating is performed as a third metal film until the plurality of openings are closed. This step is referred to as a nozzle plate forming plating step.

[0244] Since electrolytic plating has the characteristic of growing in all directions from the electrode to the space, the plating layer grows from the electrode on the bridge-like structure also in the in-plane direction of the silicon wafer to form a plurality of openings. Can be blocked. In the case of this embodiment, the width of the slit-shaped opening is set to 30 μm, so that the nickel plating layer as the third metal film has a thickness of 1 μm.
What is necessary is just to grow 5 micrometers or more.

Further, the nozzle hole which is expected to have a larger opening area than the opening does not close in the nozzle plate forming plating step. Further, in the present embodiment, since the nozzle hole diameters of the second metal film and the silicon nitride film are different from each other, it is possible to minimize the wraparound of the nickel plating layer in the nozzle hole portion. That is, since the silicon nitride film is insulative, no plating layer is formed thereon, and the growth is limited only to the growth from the gold film, so that the size and shape of the nozzle hole can be easily controlled. FIG. 16 (q) shows a state where the opening is closed and the vibration transmission rod 21 has grown to an appropriate size.

Thereafter, the positive photosensitive resist 55 is removed, and after cleaning and surface treatment, a print head in which the desired nozzle plate 1, liquid chamber partition 3, vibration plate 5, and vibration transmission rod 21 are integrated is obtained. (FIG. 16 (r)).

At this time, the structure of the film of the diaphragm is a silicon, chromium film, gold film, and nickel film when viewed from the liquid chamber side. If the silicon portion does not have an appropriate thickness as a diaphragm, the positive photosensitive resist 55 is removed, and then the silicon wafer is again subjected to anisotropic etching with a potassium hydroxide aqueous solution.

In this embodiment, the vibration transmission rod and the third metal film are formed simultaneously by electrolytic plating, but they may be formed separately as a matter of course. As one example of such a case, after forming the vibration plate 5, after protecting the surface B with a photosensitive resist, a second photosensitive resist is formed on the surface A, and a vibration transmission rod is formed by electrolytic plating. The anisotropic etching of the single crystal silicon wafer may be performed by removing the photosensitive resist.

(Embodiment 9) FIGS. 17 and 18 show a simple manufacturing process diagram of a print head manufactured according to the present invention.
(A) to (r) indicate the order of the steps. The process diagram is shown in FIG.
FIG. 3A is a cross-sectional view of the print head taken along a line XX ′ in FIG. In the single crystal silicon wafer, the side on which the diaphragm is formed is referred to as surface A, and the side on which a plurality of openings are formed is referred to as surface B. In the figure, the lower side is surface A,
The upper side is represented by surface B.

First, both sides were polished to a thickness of about 300 μm.
Is formed on the entire surface A and surface B of the single crystal silicon wafer 7 having a crystal orientation of (110) by the CVD method or the like.
A 2,000 Å silicon nitride film 63 is formed (FIG. 17A).

A first metal film is formed on the surface A and a second metal film is formed on the surface B by vacuum evaporation (FIG. 17B). Each of the metal films is composed of a chromium film 51 having a thickness of about 400 Å as an adhesion layer and a gold film 53 having a thickness of about 2000 Å as a conductive layer and an etchant-resistant layer.

In this embodiment, the structure of the metal film is made of chromium and gold for both the first metal film and the second metal film. However, it is also possible to use titanium or platinum instead of chromium and nickel or platinum instead of gold. There is no problem in the invention. In addition, although the method of forming the metal film is also performed by vacuum deposition in this embodiment,
Instead, sputtering, CVD, plating, or the like may be used.

Next, a positive photosensitive resist 55 as a first photosensitive resist is applied to the entire surface B to a thickness of about 2 μm by a spin coater, and prebaked by a hot plate or the like. Similarly, FIG.
(C).

The surface B is exposed to ultraviolet light as shown in FIG. 17D using a quartz mask 57 on which a pattern as shown in FIG. When post-baking is performed after drying, the exposed portions are dissolved and a pattern similar to the quartz mask is formed on the positive photosensitive resist 55 as shown in FIG.

Here, the positive photosensitive resist 55 on the surface A is used.
Was formed as a protective film for protecting the gold film 53 from an etchant in the next step.

Next, using the exposed and developed positive photosensitive resist 55 as a first mask, the gold film 53 is etched with aqua regia (mixed solution of nitric acid and hydrochloric acid, mixing ratio of 1: 1 to 1: 3). . Further, the chromium film 51 is coated with a mixed aqueous solution of cerium ammonium nitrate and perchloric acid (for example, 20 g of cerium ammonium nitrate and 20 ml of perchloric acid per 1 L of pure water).
The gold film 53 and the chromium film 5
1 is patterned into the same shape as the positive photosensitive resist 55, and a plurality of openings (A in FIG. 21 (a)) and nozzle holes (FIG. 21 (a)) for forming liquid chamber partitions are formed.
B) is formed on the surface B as shown in FIG. After the patterning of the chromium film and the gold film, the positive photosensitive resist 55 is removed with a dedicated stripper for the next step, and the shape becomes as shown in FIG. 17 (g).

Although a plurality of openings are formed in the second metal film by wet etching here, sputter etching or reactive ion etching may be used.

Next, a positive photosensitive resist 55 is applied as a third photosensitive resist to a thickness of about 2 μm again on the entire surface of the surface B by a spin coater, and prebaked with a hot plate or the like (FIG. 17 (h)). ).

The surface B is similarly exposed to ultraviolet light as shown in FIG. 17 (i) using the quartz mask 57 having a nozzle hole designed to have a slightly smaller diameter than that of the quartz mask 57 described above. When post-baking is performed through development and drying with a liquid, the exposed portions are dissolved and a pattern similar to a quartz mask is formed on the positive photosensitive resist 55 as shown in FIG.

Next, the silicon nitride film 63 is etched with a dry etching apparatus using the exposed and developed positive photosensitive resist 55 as a third mask, so that the silicon nitride film 63 has the same shape as the third mask. A plurality of openings and nozzle holes for patterning and forming the liquid chamber partition are formed on the surface B as shown in FIG. After the patterning of the silicon nitride film 63, the positive photosensitive resist 55 is removed with a dedicated stripping solution for the next step, and the shape becomes as shown in FIG.

Here, a plurality of openings are formed in the silicon nitride film 63 by dry etching. However, the openings may not be formed by wet etching using a mixed aqueous solution of hydrofluoric acid and nitric acid. It is possible. In this case, the dimensional accuracy is slightly lower than in the case of dry etching.

After a gold film 53 which is a part of the first metal film on the surface A is ashed sufficiently with oxygen plasma or the like to form a diaphragm film, the nickel film 5 is used as an electrode.
9 is grown by electrolytic plating to a thickness of about 5 μm. This stage is a plating step for forming a diaphragm, and nickel is simultaneously grown on the surface B, as a result, as shown in FIG.

Since the specific resistance values of silicon and gold are significantly different, the nickel film 59 is mostly grown on the gold film 53 during the electrolytic plating step, but is not grown on the silicon wafer 7 or the silicon nitride film 63. The dimensional accuracy of the deposited gold film 53 is not affected.

At this time, the surface B may be protected with a photosensitive resist or the like so that nickel does not grow.

In this embodiment, nickel is used as the diaphragm by electrolytic plating. However, any material may be used as long as the diaphragm has the rigidity and the resistance to the etchant of anisotropic etching. Also available. Also, the forming method is not limited to the electrolytic plating method, but also includes sputtering and CVD.
Also available.

The silicon wafer 7 having undergone the above steps is 3
When immersed in a 0 wt% aqueous solution of potassium hydroxide at about 70 ° C., silicon starts to be anisotropically etched from the nozzle hole and the opening formed of plural pieces (FIG. 18).
(N)). At this time, a plurality of openings are formed as shown in FIG.
As shown in (a), a plurality of slit-like patterns each having a width of about 30 μm are arranged in parallel, and spaces are communicated with each other in the process of side etching from these openings, and finally, The required liquid chamber partition, diaphragm and liquid chamber of the print head are obtained.

At this time, since the nickel film 59 has a strong resistance to the aqueous solution of potassium hydroxide, it does not erode without special protection.

FIG. 18 (o) shows the state when the anisotropic etching reaches the silicon nitride film 63. When the anisotropic etching proceeds from the plurality of slit-shaped openings and penetrates the silicon wafer, the surface of the vibration plate viewed from the liquid chamber 6 side becomes the silicon nitride film 6 previously formed.
3 appears.

This is because if the first metal film is opened on the surface of the diaphragm viewed from the liquid chamber 6 at the time of electrolytic plating in the next step, nickel plating may grow there. The role is to avoid.

Next, a positive photosensitive resist 55 as a second photosensitive resist is applied to the surface of the diaphragm to a thickness of about 5 μm with a bar coater or the like, and is exposed and developed to form a pattern of a vibration transmission rod ( FIG. 18 (p)).

Thereafter, the nickel film 59 adhered to the surface of the second metal film when the diaphragm film was formed was used as an electrode.
Further, nickel electroplating is performed as a third metal film until the plurality of openings are closed. This step is referred to as a nozzle plate forming plating step.

Since electrolytic plating has a feature of growing omnidirectionally from the electrode to the space, the plating layer grows from the electrode on the bridge-like structure also in the in-plane direction of the silicon wafer to form a plurality of openings. Can be blocked. In the case of this embodiment, the width of the slit-shaped opening is set to 30 μm, so that the nickel plating layer as the third metal film has a thickness of 1 μm.
What is necessary is just to grow 5 micrometers or more.

The nozzle hole which is expected to have a larger opening area than the opening is not closed in the plating process for forming the nozzle plate. Further, in the present embodiment, since the nozzle hole diameters of the second metal film and the silicon nitride film are different from each other, it is possible to minimize the wraparound of the nickel plating layer in the nozzle hole portion. That is, since the silicon nitride film is insulative, no plating layer is formed thereon, and the growth is limited only to the growth from the gold film, so that the size and shape of the nozzle hole can be easily controlled. FIG. 18 (q) shows a state where the opening is closed and the vibration transmission rod 21 has grown to an appropriate size.

Thereafter, the positive photosensitive resist 55 is removed, and after cleaning and surface treatment, a print head in which the required nozzle plate 1, liquid chamber partition 3, vibration plate 5, and vibration transmission rod 21 are integrated is obtained. (FIG. 18 (r)).

At this time, the structure of the film of the diaphragm is a silicon nitride film, a chromium film, a gold film, and a nickel film when viewed from the liquid chamber side.

In this embodiment, the vibration transmission rod and the third metal film are formed simultaneously by electrolytic plating, but they may be formed separately as a matter of course. As one example of such a case, after forming the vibration plate 5, after protecting the surface B with a photosensitive resist, a second photosensitive resist is formed on the surface A, and a vibration transmission rod is formed by electrolytic plating. The anisotropic etching of the single crystal silicon wafer may be performed by removing the photosensitive resist.

(Other Embodiments) A method of manufacturing a print head which can be preferably applied to the above-described embodiments will be described below.

(Formation of Vibration Plate) In each of the above-described embodiments, the vibration plate 5 is formed by plating nickel with a film by electrolytic plating. It is only required to have corrosion resistance to alkalis and to have sufficient rigidity in function, so other materials such as silver, gold, iron, cobalt, titanium, tungsten, platinum, tantalum, stainless steel, and alloys thereof In addition to silicon nitride, silicon oxide, silicon carbide, zirconia, alumina, titania, and the like can be used as the ceramic material. As a film forming method, not only electrolytic plating in the embodiment but also sputtering, CVD, thermal oxidation and the like can be used.

(Formation of Vibration Transmission Rod) In each of the above-described embodiments, the vibration transmission rod 21 need not be provided if the space between the liquid chambers of the print head is sufficiently large as compared with the drive element. In that case,
After the silicon wafer 7 is anisotropically etched, a photosensitive resist 55 is applied to the entire surface of the vibration plate 5 with a bar coater or the like, or a dry film resist is attached to the entire surface, and is not exposed and developed as it is. Post bake. After that, a nozzle plate forming plating step is performed to close the plurality of openings. After the completion of the plating process for forming the nozzle plate, the photosensitive resist 55 is removed, and after washing and surface treatment, a print head in which the desired nozzle plate 1, liquid chamber partition wall 3, and vibration plate 5 are integrated is obtained. FIG. 25 is a cross-sectional view of the liquid chamber of the print head cut perpendicularly to the line XX ′ in FIG. 21 (a), and FIG. FIG. 25B is a diagram in which the drive element 103 is bonded to the diaphragm 5 without forming the vibration transmission rod 21.

(Formation of Water-Repellent Film) In each of the above-described embodiments, nickel plating was used for the plating process for forming the nozzle plate. At this time, the plating process was performed using Teflon eutectoid plating in which fine particles of Teflon were mixed in a plating bath. By performing the nozzle plate forming plating step, Teflon fine particles precipitate on the surface of the final nozzle plate, and water repellency can be imparted to the surface. This is not necessary for the entire plating process of forming the nozzle plate, and normal nickel electrolytic plating is performed until a plurality of openings are closed, and after the closing, nickel plating is performed at a stage where the nozzle hole is adjusted to an optimum diameter as a nozzle hole. Change to Teflon eutectoid nickel plating, and form a water-repellent film layer about 5 μm from the outermost surface.

(Application to Silicon Wafer Having Another Crystal Plane) In each of the above-described embodiments, the single crystal silicon wafer has a crystal plane consisting of (110) planes. The present invention can be applied to a silicon wafer having a crystal plane. For example, when the crystal plane is a (100) plane, a nozzle plate, a liquid chamber partition, and a vibration plate are formed by forming an etching mask in consideration of the (111) plane forming the liquid chamber partition and the direction in which side etching proceeds. Can be manufactured integrally with the print head. FIG. 26 shows an example of a mask pattern for that purpose.

[0282]

As described above, according to the present invention, since the bonding step is not required, it is possible to manufacture a print head with high dimensional accuracy. In addition, the joining strength and sealing performance of each component are improved, and interference vibration between liquid chambers is reduced. Further, since a weld line is formed on the nozzle plate surface along the opening formed by the plurality of etching masks, there is also an effect that the ink is easily cut off during the wiping operation for removing the ink attached to the nozzle plate surface. It is also possible to design an etching mask in consideration of the above.

[Brief description of the drawings]

FIG. 1 (a) to (i) of the first half of a simplified process drawing of Example 1.

FIG. 2 shows the latter half (j) to (l) of a simple process chart of Example 1.

FIG. 3 (a) to (i) of the first half of a simplified process drawing of Example 2.

FIG. 4 is the latter half (j) to (l) of a simple process chart of Example 2.

FIG. 5 (a) to (i) of the first half of a simplified process drawing of Example 3.

FIG. 6 is the latter half (j) to (m) of a simple process chart of Example 3.

FIG. 7 (a) to (i) of the first half of a simplified process drawing of Example 4.

FIG. 8 is the latter half (j) to (l) of a simple process chart of Example 4.

9 shows the first half (a) to (i) of a simple process chart of Example 5. FIG.

10 is the latter half (j) of a simple process chart of Example 5. FIG.
(L)

FIG. 11 (a) to (a) of the first half of a simplified process drawing of Example 6;
(I)

FIG. 12 is the latter half (j) of a simple process chart of Example 6.
(L)

FIG. 13 is a first half (a) to a simple process drawing of Example 7;
(I)

FIG. 14 is the latter half (j) of the simple process chart of Example 7;
(R)

FIG. 15 is the first half (a) of the simple process drawing of Example 8;
(I)

FIG. 16 is the latter half (j) of a simple process chart of Example 8.
(R)

FIG. 17 (a) to (a) in the first half of a simplified process drawing of Example 9;
(I)

FIG. 18 is the latter half (j) of the simple process chart of Example 9;
(R)

FIG. 19 is a diagram showing a relation of a (111) plane in a single crystal silicon wafer having a (110) plane on the surface.

FIG. 20 is a diagram showing a basic rule of etching and a concept of an etching mask based on the rule.

FIG. 21 is a diagram showing an example of an etching mask pattern near a nozzle hole;

FIG. 22 is a simplified cross-sectional view of a print head made by a conventional method.

FIG. 23 is a simple cross-sectional view of a print head made by a conventional method (example in Japanese Patent Application Laid-Open No. 9-85949).

FIG. 24 is a simple cross-sectional view of a print head produced by a conventional method (example in JP-A-9-70964).

FIG. 25 is a diagram showing a state of bonding between the driving element and the diaphragm when the vibration transmission rod is formed and not formed.

FIG. 26 is a diagram showing an example of an etching mask pattern near a nozzle hole when a crystal plane is a (100) plane.

FIG. 27 is an SEM image showing the nozzle plate of the print head using Example 1 as viewed from the liquid chamber side.

FIG. 28 is an SE showing a partially enlarged view of FIG. 27;
M image

FIG. 29 is an SEM image showing that a plurality of openings are not completely closed in a print head using Example 1.

FIG. 30 is an SE showing a partially enlarged view of FIG. 29;
M image

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle plate 3 Liquid chamber partition 5 Vibration plate 6 Liquid chamber 7 Single crystal silicon wafer 9 Nozzle hole 21 Vibration transmission rod 51 Chromium layer 53 Gold film 55 Positive photosensitive resist 57 Quartz mask 59 Nickel film 61 Negative photosensitive resist 63 Silicon nitride 103 drive element 105 ink inlet 107 base

Claims (18)

[Claims] A liquid chamber surrounded by a nozzle plate, a liquid chamber partition wall, and a vibration plate, wherein deformation of the vibration plate generates internal pressure in ink filled in the liquid chamber and forms the internal pressure on the nozzle plate. A print head of an ink jet printer which enables printing on a recording medium by ejecting ink droplets from a nozzle hole formed, wherein one surface of a single crystal silicon wafer is designated as surface A, and (1) a single crystal silicon wafer Forming a first metal film composed of at least one layer on the entire surface of the surface A, and (2) forming a second metal layer composed of at least one layer on the entire surface of the surface B opposite to the surface A of the single crystal silicon wafer. Forming a metal film of
(3) A first photosensitive resist patterned by photolithography is formed on the surface B of the single-crystal silicon wafer, and the first photosensitive resist is used as a first mask to form the first photosensitive resist. Forming a nozzle hole and a plurality of openings in the second metal film, and then removing the first photosensitive resist; and (4) the first metal on the surface A of the single crystal silicon wafer. Forming a diaphragm film having a predetermined thickness required as the diaphragm on the entire surface of the film; and (5) forming the diaphragm on the surface B of the single crystal silicon wafer as a part of the liquid chamber partition wall.
Performing anisotropic etching of the single-crystal silicon wafer using the metal film as a second mask; and (6) using photolithography on the diaphragm film on the surface A of the single-crystal silicon wafer. Forming a patterned second photosensitive resist, and (7) forming a third metal film of at least one layer on the entire surface of both surfaces of the single-crystal silicon wafer, and forming the second photosensitive resist. And a step of peeling off the print head. 2. A liquid chamber having a liquid chamber surrounded by a nozzle plate, a liquid chamber partition wall, and a vibration plate, wherein the deformation of the vibration plate generates an internal pressure in ink filled in the liquid chamber and forms the ink plate on the nozzle plate. A print head of an ink jet printer which enables printing on a recording medium by ejecting ink droplets from a nozzle hole formed, wherein one surface of a single crystal silicon wafer is designated as surface A, and (1) a single crystal silicon wafer Forming a first metal film of at least one layer on the entire surface of the surface A, and (2) patterning the surface B, which is the opposite surface of the surface A of the single crystal silicon wafer, by using a photolithography method. Forming a first photosensitive resist and forming a second metal film composed of at least one layer on the entire surface of the surface B; and (3) forming the patterned first photosensitive resist. Forming a nozzle hole and a plurality of openings in the second metal film on the surface B by removing the conductive resist; and (4) the first metal film on the surface A of the single crystal silicon wafer. Forming a diaphragm film having a required thickness as the diaphragm on the entire surface of the substrate; and (5) forming the second metal on the surface B of the single crystal silicon wafer as a part of the liquid chamber partition wall. (6) performing anisotropic etching of the single crystal silicon wafer using the film as a mask, and (6) forming a second pattern formed on the diaphragm film on the surface A of the single crystal silicon wafer by using a photolithography method. (7) forming a third metal film composed of at least one layer on the entire surface of both surfaces of the single-crystal silicon wafer, and removing the second photosensitive resist. Method for producing a printing head of an ink jet printer characterized by having a degree. 3. A liquid chamber surrounded by a nozzle plate, a liquid chamber partition, and a vibration plate, wherein deformation of the vibration plate generates internal pressure in ink filled in the liquid chamber and forms the ink plate on the nozzle plate. A print head of an ink jet printer which enables printing on a recording medium by ejecting ink droplets from a nozzle hole formed, wherein one surface of a single crystal silicon wafer is designated as surface A, and (1) a single crystal silicon wafer Forming a first metal film made of at least one layer on the entire surface of the surface A, and (2) silicon nitride, oxide or silicon on the entire surface of the surface B opposite to the surface A of the single crystal silicon wafer. A step of forming an insulating film containing at least one of carbides; and (3) a step of forming a second metal film of at least one layer over the entire surface B of the single crystal silicon wafer. (4) forming a patterned first photosensitive resist on the surface B of the single-crystal silicon wafer by photolithography, and etching the first photosensitive resist using the first photosensitive resist as a first mask; Forming a nozzle hole and a plurality of openings in the second metal film and then removing the first photosensitive resist; and (5) photolithography on the surface B of the single crystal silicon wafer. Forming a third photosensitive resist patterned by using the third photosensitive resist as a third mask, forming a nozzle hole and a plurality of openings in the insulating film by an etching method using the third photosensitive resist as a third mask; Stripping a third photosensitive resist; and (6) forming a predetermined diaphragm required as the diaphragm over the entire surface of the first metal film on the surface A of the single crystal silicon wafer. Forming a diaphragm film having a thickness, and (7) using the insulating film on the surface B of the single crystal silicon wafer as a part of the liquid chamber partition as a second mask, (8) a step of performing anisotropic etching, and (8) a step of forming a second photosensitive resist patterned by photolithography on the diaphragm film on the surface A of the single crystal silicon wafer, 9) forming a third metal film composed of at least one layer on both surfaces of the single-crystal silicon wafer, and stripping the second photosensitive resist. Manufacturing method. 4. Prior to the step of forming at least one first metal film on the entire surface A of the single-crystal silicon wafer, (0) nitriding silicon on the entire surface A of the single-crystal silicon wafer 4. The method according to claim 1, further comprising a step of forming an insulating film containing at least one of a substance, an oxide, and a carbide. 5. The method according to claim 1, wherein the anisotropic etching is performed until the etching depth reaches an insulating film on the surface A of the single crystal silicon wafer containing at least one of a nitride, an oxide and a carbide of silicon. The method for manufacturing a print head of an ink jet printer according to claim 4, wherein: 6. The method according to claim 1, wherein the anisotropic etching is performed until the etching depth reaches the first metal film on the surface A of the single crystal silicon wafer. A method for manufacturing a print head for an inkjet printer according to claim 3. 7. In the anisotropic etching, after the etching depth reaches the first metal film on the surface A of the single crystal silicon wafer, the surface of the first metal film is oxidized. Claim 1, characterized in that
A method for manufacturing a print head for an ink jet printer according to claim 2. 8. The anisotropic etching according to claim 1, wherein the etching depth is stopped before reaching the first metal film on the surface A of the single crystal silicon wafer. A method for manufacturing a print head for an ink jet printer according to claim 3. 9. After forming the third metal film by stopping the etching depth in the anisotropic etching before reaching the first metal film on the surface A of the single crystal silicon wafer, 4. The method according to claim 1, wherein the anisotropic etching is performed again until the first metal film is reached. 10. A plurality of openings formed in the second metal film are formed by forming a slit-shaped pattern having a combination of several widths, lengths, and angles in the same direction as the longitudinal direction of the liquid chamber partition wall. 5. The method for manufacturing a print head for an ink-jet printer according to claim 1, wherein the print head is configured by the following. 11. The method according to claim 1, wherein the width of the slit-shaped pattern is restricted to twice or less the thickness of the single crystal silicon wafer. The method for producing a print head of an inkjet printer according to the above. 12. An arrangement interval of the slit-shaped patterns is equal to or less than a length that allows adjacent openings to communicate with each other by side etching generated when performing the anisotropic etching. 5. The method for manufacturing a print head of an ink jet printer according to claim 1, wherein 13. The method according to claim 1, wherein the diaphragm film is formed by an electrolytic plating method. 14. The vibration film according to claim 1, wherein the vibration film is made of nickel or gold.
A method for manufacturing a print head for an inkjet printer according to claim 4 or claim 13. 15. The method according to claim 1, wherein the third metal film is formed by an electrolytic plating method. . 16. The print head according to claim 1, wherein the third metal film is made of nickel or gold. Production method. 17. The method according to claim 1, wherein the third metal film has a water repellent surface. The method for producing a print head of an inkjet printer according to the above. 18. The single crystal silicon wafer according to claim 1, wherein the crystal orientation is (110) or (100), and both the surface A and the surface B are mirror-polished. A method for manufacturing a print head for an inkjet printer according to claim 3.