JPH0929970A - Ink jet recording head and method of manufacturing the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To solve the deterioration of printing quality of satellites and the like at the time of printing due to the instability of the meniscus of the ink nozzles of an inkjet recording head. An ink flow path wall 29 and an orifice plate 23 are formed of a photosensitive resin material 4, and a developing residue 74 is formed on the surface of the substrate so as to taper from the center of the substrate to the side of the orifice plate. At the time of joining to the plate, the joining is performed so that the hanging portion 22 of the adhesive is formed on the lower surface of the top plate, and then the nozzle 6 is formed using an excimer laser. [Effect] The three-dimensional nozzle formed by the high-power excimer laser and the two-dimensional nozzle formed by the photolithography can be smoothly connected, the movement of the meniscus in the ink droplet ejection mechanism is stabilized, and the printing quality is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head that ejects ink droplets to form an image on a recording medium, and a method for manufacturing the same, and more specifically, a method for manufacturing an ink flow path and an ink ejection port. Regarding

[0002]

2. Description of the Related Art Generally, an ink jet recording head (hereinafter referred to as a "recording head") applied to an ink jet recording system has an ejection port for ejecting ink,
A liquid chamber that stores ink to be supplied to the ejection port, an ink channel that connects the ejection port and the liquid chamber, and energy for ejecting ink that is provided in a part of the ink channel An energy generating element for generating and an ink supply port for supplying ink to the liquid chamber from the outside are provided. The following is known as a typical method of manufacturing a conventional recording head.

(1) On a first substrate 1 made of silicon or the like on which a predetermined number of ink ejection energy generating elements are arranged,
A negative type (or positive type) photosensitive dry film is attached, and a pattern corresponding to the ink discharge nozzle, the ink flow path wall, and the ink liquid chamber wall in the photosensitive dry film is transmitted through the mask (or masked light is blocked). Exposure
After development, a solid layer 4 having a pattern corresponding to the ink discharge nozzle, the ink flow path wall, and the ink liquid chamber wall is provided on the first substrate. After that, an ultraviolet curable adhesive 20 is applied on the solid layer 4 to an appropriate thickness, and a concave portion corresponding to an ink liquid chamber or a through hole 10 corresponding to an ink supply port is formed on the upper portion thereof.
A second substrate (top plate) 11 made of glass or the like on which is formed
After being aligned in a predetermined position, heating and pressure bonding are performed, the second substrate is allowed to pass through, and ultraviolet rays are irradiated to cure and completely bond the adhesive. By cutting the laminated body in which a space to be the ink flow path and the ink liquid chamber 12 is formed at the position where the ink ejection port is formed, and the end face of the solid layer is exposed,
A method for forming the ink ejection port surface (face surface) and the ink ejection port 14 (see FIG. 1 and JP-A-2-25335).

(2) A second substrate (top plate) is provided with a first substrate on which a predetermined number of ink ejection energy generating elements are arranged.
Orifice plate 23 by injection molding 11
After the ink flow path 28 and the ink liquid chamber 12 are integrally formed of resin, the ink discharge port 1 is formed by using excimer laser light.
4 (see FIG. 3 (a)), and on the first substrate 1,
A method of fixing the second substrate 11 to a support plate (base plate) 27 by pressing and fixing the second substrate 11 with the ink ejection energy generating element and the ink flow path aligned with each other by a jig such as a pressing spring 26 (FIG. 3B and See Japanese Patent Laid-Open No. 3-110172).

On the other hand, there are known problems in the manufacturing method such as the above (1). That is, when the solid layer 4 is formed, the photolithography technique frequently used in the production of printed wiring boards and the production of semiconductor elements is used, and the photosensitive resist material, the exposure light source and the developing solution used,
In terms of accuracy, although it can be formed with high accuracy by using a resist coating device, exposure device, developing device, setting of various process conditions, etc., the ink ejection port of the finally obtained recording head is not determined by the photolithographic process. Are known.

That is, the thickness of the solid layer determined by the application of the liquid resist during the formation of the solid layer or the thickness distribution / variation at the time of laminating the dry film, and the reduction of the development film and the ashing film thereafter, and the like. In addition to the factors that are suppressed in the photolithography process, including variations in width, the first major factor is the pressure distribution at the time of joining the top plate and the ink flow passage cross-sectional area due to the jig flatness / top flatness. There are factors that must be managed in order to achieve the design dimension, such as variations and variations in the ink flow passage cross-sectional area due to variations in the amount of adhesive dripping. The second major factor is that the ejection element is divided into individual ejection elements after joining, and therefore the end of the ink ejection port such as the chipped edge of the solid layer of the cured photosensitive resin and the chipped edge of the substrate at the time of separation and cutting is finished. There are also factors that must be managed as accuracy. Here, the substrate edge is made of not only silicon as a substrate material but also SiO ₂ as an insulating layer for electrical wiring or the like.
And Si ₃ N ₄ are generally provided.

FIG. 2 (a) is a view for explaining this problem as seen from the face side, and 25 is a top plate 11 based on the pressure distribution and the jig flatness / top flatness at the time of joining the top plates, and the solid state. Layer 30
It shows sledges and swells. 2 (b) is a virtual representation of the top plate 61 (a laminate of the top plate substrate 11 and the ink liquid chamber forming resin layer 30) and the adhesive 20.
It is. Reference numeral 21 in this figure schematically represents a chipping of the end face of the solid layer and chipping of the substrate edge at the time of separation and cutting, and 22 schematically represents a sagging distribution cross section of the adhesive layer 20.

The first major factor is that when an ink ejection port is formed through a cutting process, the result is a variation in the ink ejection port area, which in turn results in a variation in the ejection volume at the time of ink ejection, and the dots that affect print quality. Although there are variations in diameter, as a proposal for this problem, a method for controlling the sagging of the adhesive by devising the shape of the upper surface of the ink flow path wall, that is, the upper surface of the solid layer, has been proposed.

The second major factor is that the edge of the peripheral member forming the ink ejection port is lacking, so that the direction of the ink ejection drop is deviated from the original direction (deterioration of print quality). However, as a proposal for suppressing the chipping at the time of cutting, a method of filling and cutting the ink flow path space sandwiched between the ink flow path wall, the top plate and the substrate has been proposed.

On the other hand, as a proposal that can obtain an effect far exceeding those proposals, a photosensitive resin formed with an ink flow path wall made of a photosensitive resin by using an excimer laser whose application is expanding for fine processing in recent years. It has also been proposed to drill holes in the orifice plate (see FIGS. 5 (a) and 5 (b)). This is special fair 4-5
This is an improved means compared to the method proposed in Japanese Patent No. 9144, and in order to manufacture a large number of recording heads at low cost, even the form of the conventional example (2) is put to practical use as an ink ejection nozzle forming method. That is the method used.

In this proposal, since ink ejection ports and ink ejection nozzles are formed by processing through holes in a resin orifice plate by utilizing ablation by an excimer laser, the ink ejection port area is basically an optical mask. Therefore, it is possible to achieve high accuracy, and it is a proposal that is essentially released from the problem of adhesive sagging when joining the solid layers, chipping when cutting, and the like.

[0012]

However, the above-mentioned conventional method of manufacturing a recording head has the following problems.

In the method of the conventional example (2), since the ink flow path walls of the top plate are mechanically pressure-bonded and fixed to the first substrate without being adhesively fixed, the top plate after injection molding is performed. An essential problem is that a floating portion 24 or the like appears on the ink flow path wall due to the degree of warpage, the distribution / variation of the pressure contact fixing strength, and the like, and adjacent ink flow paths leak. This is a phenomenon called crosstalk, and the kinetic energy required for ink ejection fluctuates depending on whether ink ejection from the adjacent ink flow path occurs or not, resulting in a large or small print dot diameter, or As the ink ejection speed decreases, the distortion increases,
This causes deterioration of print quality. At present, it is the actual situation that the drive pattern of each ink ejection energy generating element is devised so as to be as inconspicuous as possible, but as the number of nozzles increases to 64, 128, 256, it cannot be ignored. Has become a problem (see Fig. 4).

On the other hand, formation of the ink discharge nozzle using the excimer laser irradiation in the above-mentioned conventional example (1) has the following problems. That is, a three-dimensional nozzle processed by using ablation of excimer laser light and a two-dimensional flow path (horizontal pattern on the substrate surface) formed by photolithography are geometrically linked. However, in some cases, such as when driven at a high recording frequency, there is no matching due to the ink ejection mechanism.

That is, after the electric pulse is applied to the electrothermal converting element 2, the ink column is extended from the ink ejection port 14 as the bubble 71 is formed, and the ink droplet is formed due to the surface tension and is smoothly ejected. To meniscus 7
If the retreat / return of No. 5 is not performed, the sub-droplet 73 formed behind the main drop 72 becomes unstable and originally flies in the same direction as the main drop, catches up with the main drop, and becomes integral with the main drop. The sub-droplet that should land on the paper landed at a position different from that of the main drop, resulting in deterioration of printing quality such as satellite and splash. (See FIGS. 6A to 6F).

In such a case, character printing (printing of characters such as alphabets and kanji) may be acceptable in terms of print quality, but especially in image printing (hard copy of screen, shaded graph, image, etc.). However, because the print quality is quite noticeable, there are times when the fine mode, etc. is provided to make it inconspicuous with the unique variation factors of each nozzle. Naturally, the actual recording speed is lowered, and the control system for performing such processing is costly.

[0017]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has a high yield (yield, low cost, high accuracy, high reliability (high density recording). It is an object of the present invention to provide an inkjet recording head having a high-density ejection port arrangement which can be applied and a manufacturing method thereof, and has the following means.

(1) A substrate, and at least an ink discharge port, an ink flow path, an ink liquid chamber, an ink supply port, and an ink flow path wall made of a photosensitive resin, and then joined to a top plate. In an inkjet recording head that forms an ink ejection port surface (face surface) by cutting, an orifice plate on which an ink ejection nozzle is formed later is provided, and the orifice plate is made of a photosensitive material of the same material as the ink flow path wall. A method for manufacturing an ink jet recording head, characterized in that it is made of a resin and is formed at the same time as an ink flow path wall, and an ink discharge port is formed by using an excimer laser.

(2) A method for manufacturing an ink jet recording head, characterized in that the face surface is provided with positioning means for excimer laser processing of the orifice plate.

(3) A method for manufacturing an ink jet recording head, wherein the orifice plate has a thickness of 5 to 50 μm.

(4) At the joint surface between the upper surface of the ink flow path, the ink liquid chamber, the ceiling plate forming the ink supply port, etc., and the ink flow path wall made of a photosensitive resin, Using a photo-curable adhesive for joining, the adhesive from the bottom surface of the top plate in the ink flow path toward the orifice plate,
A method for manufacturing an ink jet recording head, characterized in that the ink jet recording head is adapted to fold down.

(5) At the joint surface between the ink flow path wall and the orifice plate and the substrate, the undeveloped portion is caused in the photosensitive resin as the orifice plate material, and the undeveloped portion is thermally cured to cause the orifice plate. A method for manufacturing an ink jet recording head, characterized in that

(6) The height of the lower end of the ink ejection port on the face surface (ink ejection port surface) of the recording head is a circle conversion diameter R of the ink ejection port area from the contact interface between the substrate and the orifice plate constituent material. 1/3 or more of the above.

(7) A method of manufacturing an ink jet recording head, wherein the recording head is subjected to water repellent treatment on the outer surface of the orifice plate before forming the discharge nozzle by the excimer laser light.

(8) A method for manufacturing an ink jet recording head, wherein the substrate has an ink discharge energy generating element integrally formed thereon.

(9) A method for manufacturing an ink jet recording head, wherein the ink ejection energy generating element is an electrothermal converting element.

(10) An ink jet recording head manufactured by the above method, or an ink jet recording cartridge in which an ink tank is integrated.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, a substrate having an ink flow path wall, an orifice plate and the like formed in advance with a photosensitive resin material is provided in a through hole corresponding to an ink supply port or a part of an ink liquid chamber. When the top plate with the corresponding digging recess is bonded and the through hole is processed using excimer laser at the part corresponding to the ink discharge nozzle of the orifice plate, then the ink discharge port is formed by the conventional cutting process. In addition to essentially solving the problem of lack of ink, ink ejection performance in a recording head in which an ink ejection port is formed by using an excimer laser, particularly printing quality problems such as satellite and splash can be solved. Moreover, according to the present invention, a recording head having a structure in which the ink flow path wall forming material and the ink flow path ceiling forming material are in close contact with the substrate is structurally obtained, and the ink ejection performance is greatly superior to that of the conventional example (2). It is a thing.

[0029]

【Example】

Embodiment 1 FIG. 17 is a block diagram showing the features of the present invention, and FIG.
16 to 16 are the means (1) to the present invention.
The outline of the configuration and manufacturing procedure of the ink jet recording head relating to the method of the present embodiment that best expresses the features (6) and (8) to (10) is shown. Hereinafter, description will be given with reference to these drawings.

In this embodiment, an ink jet recording head having up to five ejection ports is shown for convenience, but the same applies to a high density multi-array ink jet recording head having more ejection ports. Needless to say. Further, a recording head integrally provided with ink flow passages having different ink discharge droplet volumes, for example, 64 black ink nozzles having a discharge volume of 80 ng is provided, and yellow and magenta having a discharge volume of 40 ng are provided in the same row. Alternatively, a structure such as a 360-dpi recording head having a four-color integrated structure in which 24 nozzles for each cyan color are provided may be used.

First, a silicon wafer having a thickness of 0.625 mm is used as the substrate 1, and the electrothermal conversion element 2 is provided on the substrate 1.
(Heater made of material HfB ₂ ), wiring and electrode 3 (material Al) corresponding to the electrothermal conversion element are formed by a sputtering device, and then photosensitive resist coating / exposure
By a process similar to semiconductor manufacturing such as development and resist peeling, the electrothermal conversion elements 2 are arranged on the same surface of the substrate 1 at a predetermined interval (see FIG. 7, the following figures depict one ejection element). However, in reality, a large number of ejection element regions are provided on the substrate). Although not shown, an electric insulating film S is formed on the element surface including each electrode and each electrothermal conversion element for the purpose of improving durability.
Various functional layers such as iO ₂ , a protective film Ta, and an electrode oxidation preventing film Au were provided.

Subsequently, a negative photosensitive dry film SX-325 manufactured by Tokyo Ohka Kogyo Co., Ltd. is laminated on the substrate 1, and an ink flow path wall (29) facing each electrothermal conversion element and ink. Using the pattern mask of the liquid chamber wall (5) and the orifice plate (23), the solid layer 4 was formed through the steps of exposure and development with trichloroethane (see FIG. 8).

At this time, of the portion surrounded by the ink flow path wall 29 and the orifice plate 23, approximately 30 μm
The condition of the pattern arrangement and the developing process, so that the undeveloped development may occur smoothly on the substrate surface in the area of about m square.
The development method was selected. That is, the solid layer patterns of the respective discharge elements are arranged in the same direction in the substrate (not the opposed arrangement in which two rows face each other), and the paddle method and the spin method are not preferable as the developing method, and the shower developing method is not preferable. The shower is not a reciprocating showering but one-way, parallel to the ink flow path wall pattern and opposite to the ink discharge direction, and the shower nozzle spreads at right angles to the substrate in the operation direction. Was decided to be used. In fact, the undeveloped portion was tapered such that the ink flow path wall height was 32 μm, the ink flow path wall portion and the orifice plate surface portion were about 3 to 5 μm, and the ink flow path center portion was almost zero.

Dummy nozzles 62 having no orifice plate were simultaneously provided by the solid layer 4 on both sides of the flow path region in which the electrothermal conversion element 2 was provided. This is used as a reference marker when processing with an excimer laser beam later, and may be provided on one side or may not take the form of a dummy nozzle. The purpose is to provide a pattern on the face surface 15 which serves as a position determining means at the time of irradiation of excimer laser after separation and cutting in patterning the solid layer 4.

Next, a through hole 10 for supplying ink and a digging concave portion which is a part of the ink liquid chamber are formed (the digging concave portion is not shown), and the thickness is 1.0 mm.
Second substrate 11 made of Tempax glass (top substrate)
A photosensitive dry film of the same material as that of the ink flow path wall was laminated on the surface of the recessed portion, and the solid layer 30 was formed through the steps of exposure and development (see FIGS. 9 and 10).

The solid layer 30 improves the adhesion between the ink passage wall on the side of the substrate 1 and the ink chamber wall and the top plate, and the surface in three directions within the ink passage (the wall 2 excluding the substrate surface). The surface and one surface of the ceiling) are made of the same material to maintain the same wettability to ink and to stabilize the ink ejection. As a supplement, plasma ashing treatment and application of a silane coupling agent are performed from the viewpoint of improving adhesion reliability before forming the solid layer 4 on the substrate and before forming the solid layer 30 on the top plate.

Then, on the surface of the top plate on which the solid layer 30 is formed, a roll coater is used to coat the adhesive 20 with a thicker layer of 5 μm.
It was applied to a thickness of m (see FIG. 11). U as an adhesive
Nopco Cure CPA-made by San Nopco Co., Ltd. that contains urethane-based acrylic ester as a main component from among V-curable resins
4 (trade name) was selected.

The top plate 61 thus pretreated and the substrate 1 on which the solid layer 4 is previously formed face each other with the adhesive layer 20 sandwiched between them, and after predetermined alignment, temporary fixing is performed. (See FIG. 12). For temporary fixing, a two-component instantaneous elastic adhesive 66 (Peg α (trade name) manufactured by Cemedine Co., Ltd.) was used in the peripheral portion of the substrate where the ejection element could not be taken.

Subsequently, the laminated body 16 (substrate 1, solid layer 4, adhesive layer 20) temporarily fixed to the movable pressurizing jig 64 for joining is used.
・ The solid layer 30 / top plate substrate 11) is heated to form the top plate substrate 11
Fixing jig 6 made of ultraviolet-transparent material provided on the side
3 (here, made of glass) was pressed from below and joined (see FIG. 13). The conditions of heating and pressurization depend on the pattern width of the solid layer 4 forming the ink flow path wall, the curing conditions of the adhesive layer 20 to be selected, and the like, but in this embodiment, the inner surface of the orifice plate is positively affected. Since the conditions were set so that the adhesive drips, heating at 100 ° C and
The condition of kg / cm ² is the bonding state (see FIG. 14 (a))
It was also good in the adhesion reliability test thereafter (the amount of sagging after curing was about 5 μm at the central portion of the ink flow passage and about 10 μm at the ink passage wall portion, which was a natural sagging amount).

Qualitatively, when the heating temperature of the laminate 16 is high, that is, when the temperature of the adhesive layer 20 is high, low pressure pressurization is sufficient, and conversely, when the temperature is low, high pressurization is applied. Will be needed. On the other hand, if the bonding temperature is too low, the adhesive layer 20
The adhesive strength at the interface between the solid layer 4 and the solid layer 4 is weak, and when the adhesive layer 20 is subsequently cured using ultraviolet rays, peeling easily occurs at the interface. Further, if the adhesion temperature is too high, the viscosity of the adhesive decreases, so that even if pressure is applied at a controllable low pressure, the solid layer 3
The adhesive layer 20 between 0 and the solid layer 4 is entirely extruded, and as a result, the adhesive is adhered only at the portion of the ink flow path space that is hung down on the side surface of the solid layer 4 (see FIG. 14 (b)), the adhesive strength is weak and peeling is likely to occur.

With this, the substrate 1 on which the solid layer 4 is formed,
The top plate 61 provided with the solid layer 30 was joined, but the substrate was cooled to about 30 ° C. in this pressurized state, and the UV lamp provided on the top of the top plate was made to emit light to make the glass plate. Through the fixing jig 63, the elastic thin film 65 provided to reduce the load applied to the top plate 61 at the time of pressurization, the top plate substrate 11 and the solid layer 30 made of a photosensitive resin,
The adhesive layer 20 was irradiated with ultraviolet rays 41 to be cured (FIG. 1).
3). After that, heat curing was also performed for complete curing.

Thus, between the top plate substrate 11 and the substrate 1,
Integrated laminate 16 in which solid layer 4 and solid layer 30 are formed
An ultraviolet-curable adhesive tape for wafer dicing was attached to the back surface of the substrate 1. Next, the semiconductor wafer is set on a cutting table of a general blade dicing machine for dicing to form a face surface (in this embodiment, the orifice plate has a thickness of 20 μm).
Position), using a resin blade of # 2500 diamond abrasive grains and pure water as cutting fluid and cooling water, a half cut into the adhesive tape, that is, a full cut of the laminate 16 A cutting process was performed. At this point, the solid layer 4 forming the dummy nozzles 62 provided on both sides of the ink flow path 28 in which the electrothermal conversion element 2 is disposed.
The end face is exposed.

As described above, the ink ejection port surface (face surface) 1
5 was formed and divided into individual discharge elements 17 (form of FIG. 12). Inside the orifice plate 23 of this discharge element, not only the nozzle taper in the plane direction when the solid layer 4 is formed but also the nozzle taper in the vertical direction which is the point of the present invention is obtained. That is, on the substrate surface side, the taper due to the positive development residue during patterning of the ink flow path wall causes the adhesive to naturally stick around the orifice plate on the solid layer 30 surface side under the top plate substrate 11. The taper is formed by providing the structure that hangs down.

Next, after aligning the optical axis of the excimer laser with the workpiece with reference to the dummy nozzles 62 provided near both ends of the face surface 15, the ink is directed toward the orifice plate facing the ink flow path. The ink discharge nozzle 6 was formed by irradiating the excimer laser light 31 from the direction of 0 ° on the front surface and processing the through hole. FIG. 15 schematically shows the state of this processing, and 7 is a portion which has disappeared by being exposed to the excimer laser light. The height from the substrate surface to the nozzle was set so that the lower end of the nozzle was 5 μm above the substrate. This was determined in order to separate the nozzle from the interface of the orifice plate and the substrate on the face surface 15 and at the same time, to smoothly connect the taper due to the undeveloped residue and the excimer laser processed nozzle.

The structure of the excimer laser processing apparatus used here is as shown in FIG. 18, 32 is the excimer laser main body, 33 is a half mirror and power meter for monitoring the laser power, and 34 is a discharge port pattern. , An optical lens system for projecting excimer laser light onto a work (such as a cylindrical lens group, a fly's eye lens group, a field lens group, and a projection lens group), 35 is a quartz glass mask on which a projection pattern is formed, and 36 is a work. The moving stage and mounting base, 37 is an observation system for performing image processing, 38 is a control system for controlling laser oscillation timing, work positioning, and the like, and 39 is a device for circulating and refining excimer laser gas.

The processing conditions are as follows:
F excimer laser (wavelength 248 nm) light is applied to the solid layer 4
At a vertical cross section of 10 ° and a repetition frequency of 200P
Upon irradiation with PS and a pulse energy density of 1500 mJ / cm ² , the benzene ring sufficiently absorbs ultraviolet light, and thus a predetermined ablation process (through hole having a thickness of 20 μm) was performed within 100 pulses. Further, in order to prevent the by-products at the time of ablation from adhering to the inside of the ink flow path and the face surface, helium gas was sprayed at the same time as the processing. Until the through holes start to be made, contaminants due to ablation scatter on the excimer laser light irradiation side, that is, on the face side.However, in practice, cleaning can be performed before the water repellent treatment in the next step. In particular, no problem was observed in the adhesion reliability of the water repellent layer.

Further, from the moment the through hole begins to be formed, the contaminants are scattered in the space inside the ink flow path. However, when the resin is ablated as in this embodiment, the level of the pulse energy density is 1500 mJ / cm ² . Then about 1
Since an etching rate of about 0.2 to 0.5 μm can be obtained with a pulse, the target resin that actually scatters into the ink flow path is very small, and the ink flow path and ink ejection nozzles are not clogged, and there is no contamination. It was not observed that the wettability changed and the ink ejection became unstable due to the above. This is because the effect of helium gas is also obtained.

As a supplement, in the case of excimer laser light (wavelength 248 nm) of about 1500 mJ / cm ² , the hole area on both sides of the orifice plate 23 having a thickness of 20 μm is 4
% (Hole diameter is 2% or less), and since it is a substantially straight nozzle, even if it is used as an ink discharge nozzle of an inkjet recording head, there is no problem such as a decrease in discharge speed and poor print quality. On the other hand, in the example of the conventional example (2), the same wavelength of 248 nm is 100
At an energy density of 0 mJ / cm ² , in the orifice plate made of polysulfone of 40 μm, the ratio of the diameter on the incident side was 1.2 and the ratio on the incident side was 1.4 when the emission side (through hole side) was 1.

Using the ejection element 17 (see FIGS. 16 and 17) of the recording head thus manufactured, water repellent treatment (ink repellent treatment) of the face surface 15, electrical connection by wire bonding, etc., The ink supply system was connected and the ejection performance test and the printing durability test were performed on the printer. The performance as a recording head, for example, the ejection maximum frequency, the durability of the electrothermal conversion element that is the ink ejection means, In terms of printing performance, the accuracy of the landing point on the recording material, the dot diameter, etc. fully satisfied the performance required in the design, and the deterioration of printing quality due to the instability of the meniscus, which was a problem in the conventional example, was also improved. I was able to confirm. of course,
In this embodiment, the ink discharge nozzle has an example of a circular cross section, but the same applies to a nozzle having a rectangular or trapezoidal cross section similar to the cross section of the ink flow path.

Moreover, even if a crack or the like is generated at the interface between the substrate 1 and the orifice plate 23 during cutting, unlike the edge shooter type ink ejection port of the conventional example (1), the crack itself is the ink ejection port. Since the water repellent layer having a thickness of 0.1 μm or less is provided on the entire face surface, no adverse effect on ink ejection was observed. Of course, there was no problem in reliability such as peeling of the ink flow path wall even in a high temperature storage test under immersion in ink.

As a supplement, the thickness of the orifice plate on which the ink discharge nozzle is formed by the excimer laser of this embodiment is 20 μm, but the range of 5 to 50 μm is preferable for the ink jet recording head. This requires a cutting margin of at least 3 μm considering the cutting tolerance.
In addition, the lower limit of 5 μm is required considering the external force when the paper is jammed in the printer. On the other hand, in excimer laser processing, in order to obtain a nozzle that is almost straight,
As the thickness becomes thicker, the processing with higher energy density becomes necessary. Therefore, the upper limit is preferably 50 μm.

Second Embodiment Although details are omitted, FIG. 19 is a configuration diagram of the second embodiment.
Hereinafter, description will be given based on this figure. First, an electrothermal conversion element 2 (a heater made of TaN ₂ ) and an electrode (material Al) corresponding to the electrothermal conversion element are formed on a substrate 1 made of borosilicate glass by a sputtering apparatus and an electron beam film forming apparatus. After forming the film, patterning was performed in the same manner as in Example 1, and the electrothermal conversion elements were arranged on the same surface of the substrate with a predetermined interval.

In this embodiment, the recording head is integrally provided with the ink flow paths having different ink discharge droplet volumes,
64 black (BK) ink nozzles having a discharge volume of 80 ng are provided, and 24 nozzles for each color of yellow (Y), magenta (M), and cyan (C) having a discharge volume of 40 ng are provided in the same row. The electrothermal conversion element array for the recording head having the four-color integrated structure is formed.

Next, as in Example 1, the solid layer 4 was formed. Here, it is necessary to integrally provide the ink discharge nozzles having different ink discharge volumes, but the thickness of the solid layer 4 is the same even in the ink flow paths having different discharge volumes due to its forming method, and the solid layer 4 has already been arranged. A design method was used in which the size / shape / position of the electrothermal conversion element, the ink flow path width, and the ink ejection nozzle were controlled.

That is, regardless of the size of the ink discharge nozzles, the centers of the ink discharge nozzle rows are provided on the same line, and the width of the color (yellow, magenta, cyan) ink flow paths is wider than that of black. By making it narrower, more development residue and adhesive dripping,
An appropriate taper could be obtained from the resin layer 30 as well as from the substrate 1 with respect to the ink ejection nozzles farther than black. Even if they are not arranged on the same line by design, for example, by shifting the black and color discharge timings,
It is possible to land on the same line in printing, but it is also desirable to judge whether or not to select this, depending on the balance between the undeveloped portion and the dripping of the adhesive.

Subsequently, the top surface was subjected to water repellent treatment after joining the top plate and separating and cutting into each discharge element.
The water repellent treatment is not specified, but Asahi Glass Co., Ltd.
A fluorine-based resin film (thickness: about 0.05 μm) was formed using Cytop (trade name).

The orifice plate facing the ink flow path of this water-repellent discharge element was irradiated with an excimer laser to form an ink discharge nozzle as in Example 1. This example is different from Example 1 in that the water repellent treatment is performed before the nozzle processing, but since the water repellent treatment is performed before the ink ejection ports are formed, management of the water repellent agent entering the ink ejection nozzles is managed. Was unnecessary and could be easily processed. On the other hand, the water repellent used in this example is transparent (no absorption) to the excimer laser light, but ablation occurs under the water repellent thin film, which does not hinder the ink discharge nozzle processing. Has also been confirmed.

Color recording was carried out in the same manner as in Example 1 using the discharge element thus formed.
Due to the effect of the present invention, it is possible to obtain a recording head which does not have satellites and discharges ink smoothly.

Further, as a result of observing the ink ejection and face surface observation in various print patterns and all solid patterns, in order to eliminate the influence of the interface between the substrate 1 and the orifice plate 23, the lower end of the ink ejection port and the interface can be eliminated. It was also confirmed that the distance between and is preferably 1/3 or more of the circle equivalent diameter R of the ink ejection port (“ink ejection port area S / square root of pi”). As a supplement, it depends to some extent on the surface tension of the ink used and the state of the face surface (surface roughness, water repellency, etc.). Is generally performed, and the effect was confirmed in the above range.

Through the above Examples 1 and 2, the purpose of the present invention is to provide a photosensitive resin material in a recording head which is excellent in ejection characteristics such as no nozzle crosstalk due to the ink flow path wall being in close contact with the substrate. When forming the ink flow path wall and orifice plate with, develop so as to cause undeveloped residue on the substrate surface, and when joining the top plate, join so that the adhesive drips on the bottom surface of the top plate. The smooth connection between the 3D nozzle using the high-power excimer laser light and the 2D nozzle using the photolithography is possible, and the movement of the meniscus in the conventional ink droplet ejection mechanism is unstable, resulting in deterioration of the printing quality of satellites. There is a point to solve the problem.

Further, although the water repellent treatment is conventionally performed after the ink ejection port is formed, by performing the treatment before irradiating the excimer laser light of the present invention, the water repellent treatment can be performed more easily and at low cost with certainty. It enables the formation of a water film.

Further, according to the present invention, since the recording head can be provided with high yield, high productivity, high accuracy and low cost, the ink ejection energy generating element can be integrally formed on the substrate even in the ink jet recording system. This is particularly advantageous in a recording head of an inkjet recording system in which ink droplets are ejected by utilizing thermal energy and recording is easily performed. In that case, not only the black monochromatic recording head but also the color recording head or the serial scan type recording head, the full line having a length corresponding to the maximum width of the recording medium that can be recorded by the recording device is used. The effect is sufficiently exerted even in the case of a recording head of a type, or even if the ink used is not liquid at room temperature, that is, ink that is liquefied or softened during ejection. The color recording head and the full-line type recording head described above may be either one configured by combining a plurality of recording heads or one recording head integrally formed.

[0063]

As described above, according to the present invention, by forming the ink flow path wall and the orifice plate with the photosensitive resin material, the conventional problem of cracking or chipping at the time of division into each element is released. In addition, when forming the ink flow path wall and the orifice plate, the substrate surface is developed so as to cause an undeveloped residue, and when the top plate is joined, the adhesive is dripping on the bottom face of the top plate. This enables a smooth connection between the 3D nozzle using the high power excimer laser light and the 2D nozzle using the photolithography, and the movement of the meniscus in the conventional ink droplet ejection mechanism is unstable, resulting in deterioration of the printing quality of satellites and the like. You can solve the problems that you had.

Further, the combination with an ink jet recording system utilizing thermal energy, which allows the ink discharge energy generating element to be easily integrally formed on the substrate, is most effective when a recording head is provided with high productivity, high yield and low cost. The recording head that is effective, and is stable, has excellent ejection performance and high reliability.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a discharge element for explaining a conventional example (1).

FIG. 2A is a view of a face surface of a discharge element for explaining the problem of the conventional example (1). FIG. 9B is a perspective view of the adhesive dripping into the ink flow path for explaining the problem of the conventional example (1).

FIG. 3A is a diagram of a top plate integrally with an ink flow path for explaining a conventional example (2). (B) is a block diagram of the discharge element explaining the prior art example (2).

FIG. 4 is a sectional view of an ink flow path of an ejection element (a sectional view taken along the line AA in FIG. 3B) for explaining the problem of the conventional example (2).

FIG. 5 is a perspective view of an ink flow path and an orifice plate for explaining an improvement plan of the conventional example (1).

FIG. 6 is a horizontal sectional view of an ink ejection nozzle for explaining the problem of the improvement proposal of the conventional example (1). (A): Before application of driving electric pulse (b): During maximum bubble growth (c): Bubble contraction process (d): Ink main droplet flight process (e): Ink sub-drop flight process (f): Temporary meniscus vibration due to ink supply from the ink chamber

FIG. 7 is a perspective view illustrating formation of the electrothermal conversion element 2 on the substrate 1 according to the first embodiment of the present invention.

FIG. 8 is a perspective view illustrating formation of a solid layer 4 that forms an ink flow path wall, an orifice plate, and the like on the substrate 1 according to the first embodiment of the present invention.

FIG. 9 is a perspective view illustrating the top plate substrate 11 according to the first embodiment of the present invention.

FIG. 10 is a perspective view illustrating formation of a photosensitive resin layer 30 forming a part of an ink liquid chamber on the top plate substrate 11 in Example 1 of the present invention.

FIG. 11 is a diagram illustrating formation of the adhesive layer 22 on the top plate 61 (a laminated body of the top plate substrate 11 and the resin layer 30) according to the first embodiment of the present invention.

FIG. 12 is a perspective view illustrating temporary fixing, joining, and cutting of the substrate and the top plate according to the first embodiment of the present invention.

FIG. 13 is a perspective view illustrating joining and UV curing of the substrate and the top plate according to the first embodiment of the present invention.

FIG. 14 is an ink flow path wall 29 according to the first embodiment of the present invention.
FIG. 6 is a cross-sectional view of an ink flow path for explaining a joining state between the top plate and the top plate.

FIG. 15 is a diagram illustrating irradiation of excimer laser light in Example 1 of the present invention.

FIG. 16 is a perspective view illustrating an ink ejection element according to the first embodiment of the present invention.

FIG. 17 is a perspective view illustrating a nozzle taper state inside the orifice plate according to the first embodiment of the present invention.

FIG. 18 is a configuration diagram illustrating an excimer laser processing apparatus in Example 1 of the present invention.

FIG. 19 is a configuration diagram of an ink ejection element according to a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate (first substrate) 2 Ink ejection energy generation element such as electrothermal conversion element 3 Electrode for sending ejection signal from the outside to ink ejection energy generation element 4 Solid layer forming ink flow path wall 5 Ink liquid Chamber wall 6 Ink discharge nozzle 7 Part lost by ablation 10 Ink supply port 11 Top plate substrate (second substrate) 12 Ink liquid chamber 14 Ink discharge port 15 Face surface 16 Laminated body integrated with substrate 17 Discharge element 20 Top plate adhesive layer 21 Chips that occur during cutting 22 Top plate adhesive sag 23 Orifice plate 24 Floating part of ink flow path wall 25 Top plate warp, swell 26 Presser spring 27 Support plate (base plate) 28 Ink flow path 29 ink channel wall 30 solid layer 31 excimer laser light 32 excimer laser body 33 Power monitor system 34 Optical lens system 35 Optical mask 36 Work moving stage 37 Observation camera system 38 Excimer laser processing device control system 39 Laser gas refining device 41 Ultraviolet ray 61 Top plate (laminated body of top plate substrate 11 and resin layer 30) 62 Dummy nozzle 63 Fixing jig for joining 64 Movable pressing jig for joining 65 Elastic thin film 66 Adhesive for temporary fixing 71 Bubbles that grow and shrink on the electrothermal conversion element 72 Ink main droplet 73 Ink sub-drop 74 Solid layer Undeveloped area 4 No. 75 Meniscus

Claims (11)

[Claims] 1. A substrate, and at least an ink discharge port, an ink flow path, an ink liquid chamber, and an ink supply port,
Further, in the ink jet recording head in which the ink flow path wall is formed by the photosensitive resin, the top plate is joined, and the ink ejection port surface (face surface) is formed by cutting, the orifice in which the ink ejection port is formed later. A plate is provided, the orifice plate is made of a photosensitive resin of the same material as the ink flow path wall, and is formed at the same time as the ink flow path wall, and the ink discharge port is formed by using an excimer laser. A method for manufacturing an ink jet recording head, characterized in that 2. The face surface according to claim 1,
A method of manufacturing an ink jet recording head, characterized in that a positioning means for excimer laser processing of an orifice plate is provided. 3. A method for manufacturing an ink jet recording head, wherein the orifice plate according to claim 1 or 2 has a thickness of 5 to 50 μm. 4. An upper surface of the ink flow path according to claim 1, an ink liquid chamber, a top plate forming an ink supply port, and an ink flow path wall made of a photosensitive resin. A method for manufacturing an ink jet recording head, characterized in that a photo-curable adhesive is used for the joining on the joining surface, and the adhesive is drooped from the lower surface of the top plate in the ink flow path toward the orifice plate. . 5. The photosensitive resin, which is the orifice plate material, is left undeveloped on the ink flow path wall and the joint surface between the orifice plate and the substrate, and the undeveloped portion is heat-cured. A method for manufacturing an ink jet recording head, characterized in that it is formed as a part of the orifice plate. 6. The height of the lower end of the ink ejection port on the face surface (ink ejection port surface) of the recording head according to claim 1 is the area of the ink ejection port from the contact interface between the substrate and the orifice plate constituent member. A method for manufacturing an ink jet recording head, characterized in that the diameter is 1/3 or more of a circle conversion diameter R. 7. The method for manufacturing an ink jet recording head according to claim 1, wherein the outer surface of the orifice plate is subjected to a water repellent treatment before the discharge nozzle is formed by the excimer laser light. 8. A method of manufacturing an ink jet recording head, wherein the substrate according to claim 1 is integrally formed with an ink ejection energy generating element. 9. The method for manufacturing an inkjet recording head, wherein the ink ejection energy generating element according to claim 8 is an electrothermal conversion element. 10. An ink jet recording head manufactured by the method according to claim 1. 11. An ink jet recording cartridge comprising an ink jet recording head manufactured by the method according to any one of claims 1 to 9 and an ink tank.