JPH0373349A - Recording head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a head applied to an inkjet recording apparatus that forms recording liquid, generally called ink, into small droplets using various methods, and performs recording by adhering these ink droplets to a recording surface. Regarding the structure of the department.

Among the various recording methods currently known, the non-impact recording method generates almost no noise during recording, is capable of high-speed recording, and does not require special fixing treatment on plain paper. The so-called inkjet recording method, which can perform recording on images, is recognized as an extremely useful recording method. Regarding this inkjet recording method, various methods have been proposed so far, and some have been improved and commercialized, while efforts are still being made to put them into practical use. There is also.

In short, the inkjet recording method involves ejecting and flying droplets of a recording liquid called ink.
This inkjet recording method is a method in which recording is performed by attaching the ink to a recording material such as paper.0 This inkjet recording method uses a method of generating ink droplets and a control method for controlling the flight direction of the generated ink droplets. is broadly classified into several methods. Among them, one of the representative methods is, for example, USP3596
275 (Sweet method), USP 32980
30 (Lewis and Brown method), etc., in which an ink droplet flow with a controlled amount of charge is generated by a continuous vibration generation method, and this ink droplet flow with a controlled amount of charge is By causing the droplet to fly between deflection electrodes to which an electric field is applied, recording is performed on a recording member such as paper while controlling the trajectory of the droplet. This method is also generally referred to as a continuous method.

Other typical methods to be compared with this are, for example, USP3
747120 (S t emm
e method). This method applies an electrical recording signal to a piezoelectric vibrating element attached to a recording head that has an orifice for ejecting ink for recording, and converts this electrical recording signal into mechanical vibration of the piezoelectric vibrating element. Recording is performed by ejecting ink droplets from the oriice and adhering them to the recording member whenever necessary according to the mechanical vibrations.

This is the so-called on-day method.

In addition, a new recording method that differs in principle and idea from these methods was also proposed in the applicant's earlier application ('i-,?').
5. ! This method was proposed in No. 118798/1983). In short, this new method applies a thermal pulse as an information signal to the ink introduced into a working chamber, and according to the working force generated by the state change of the ink, the orifice attached to the previous working chamber is 1. A method in which the ink is ejected and made to fly in the form of small droplets, and the droplets are attached to a recording material such as paper to perform recording.By the way, among the various inkjet recording methods exemplified above, the following is common to all of them: Technical issues still remain to be resolved.

Among these, a particularly important issue is the establishment of multi-array recording heads and high-density integration technology for the purpose of higher-speed inkjet recording.

Moreover, in this case, it is considered important to configure a recording head such that the size, ejection speed, and ejection direction of ink droplets ejected from one ejection port are always negative.

However, it is not easy to satisfy all of these conditions required for such a recording head, especially from the viewpoint of manufacturing technology.

For example, originally one nozzle part was composed of pores,
To complete a multi-array recording head by combining a plurality of these pores, it requires a high degree of technical skill as they are extremely fine, and the pores must be arranged at a high density (e.g. 8 pores/hour). There are limits to how much people can gather together (more than a certain amount).

Furthermore, it is not easy to obtain a highly reliable high-density multi-array recording head with a good yield.

Therefore, the main object of the present invention is to provide a recording head that satisfies the above-mentioned technical problems. ) is to provide an output device.

Another object of the present invention is to provide a recording head with a new configuration that guarantees high-speed, high-resolution, high-quality recording over a long period of time. Another object is to provide a highly precisely machined recording head.

Therefore, the present invention that achieves these objects can be summarized as follows:
It has a flow path for recording liquid consisting of pores, and from an ejection port communicating with the pores, the recording liquid present in the flow path is ejected into small droplets and made to fly, and the droplets are directed to a recording surface. A recording head that performs recording by adhering to a predetermined number of ejection ports, in which a predetermined number of ejection ports are arranged in parallel, and the same number of pores are arranged in parallel at the same density as the ejection ports. This is a recording head characterized by the following.

That is, one feature of the present invention is that both the recording ink ejection opening and the acting part (the part that imparts an ejection force to the ink) in the ink flow path leading thereto have a high density. (For example, 8 pieces/battle or more) in a multi-array arrangement.

For reference, conventionally, even in this type of inkjet recording head, the number of ejection ports is 8/8, for example.
It was thought that such an arrangement would be possible even at a density similar to mine. However, with regard to the action parts, a high-density arrangement of 8 or more per unit, which is made possible by the present invention, has not yet been realized mainly due to functional limitations.

Another feature of the present invention is that the ink containing the action part
The Zi path is constructed using an unprecedentedly simple method in which another flat plate is press-fixed or adhered circumferentially on a substrate in which fine grooves are carved.

In the present invention, the method of carving the fine grooves is as follows:
There are two broad categories.

One of them is glass, quartz, and ceramics.

Using a micro cutter on a flat plate made of silicone, plastic, metal, etc.
Grooves with a size of about 0 μm to 250 μm, with a pitch of about 10
This is a method of arbitrarily cutting and forming in a range of μm or more.

Another method is to burn a desired pattern of fine grooves into photosensitive glass (for example, 7 Otoceram, etc.) and then etch the exposed areas with a so-called etching solution. Note that this method does not leave any defects such as chipping or microcraps that are normally found in the cut part, and as long as the burning pattern is uniform, the shape of the microgrooves is always uniform. has advantages over the former method.

In addition, when using the above-mentioned method of crimping and fixing the grooved substrate and another flat plate, the crimping surfaces of each other should have a surface roughness of approximately 1 μm.
It is preferable to use one of the following smooth surfaces. This smooths the crimping surface and allows both sides to be ′′! ! This is with the intention of sufficiently increasing adhesion and preventing the acting force generated therefrom from unnecessarily propagating from the obtained predetermined ink channel to other channels.

The present invention will now be described in detail according to an embodiment according to an illustrated example.

In this embodiment, a description will be given of the assembly process of a multi-array recording head.

FIG. 1 shows two types of
Two components A, B are depicted in a schematic perspective view. Fig. 1 depicts fal Fi part A, and Fig. 1bl depicts part B, respectively.

Component A is created according to the following procedure.

First, alkali metal fluoride photosensitive glass (81()2
r L1201 NtOl"zor A40s +
After polishing both sides of a flat plate of a composition containing Au + l'dZcl +CeO, 100 mm x 100 m
Cut into a size of m (thickness, 2ax). Commercial products of this type of photosensitive glass include Photoceram, Photoform (trade name: manufactured by Corning Incorporated), and any of them may be used. Next, an information laser (not shown) is applied to the photosensitive glass plate PG prepared in this way at 620 nm.
The 310 nm coupling wave of the dye laser beam excited at m was extracted, and the pitch was 10011 m, 501 Jm
This interference fringe ti90m has a width of 0.
It was uniform within the plane of x 9o #11. or,
The power of the laser light source is IOW, and since the photosensitive glass has an absorption of 310 μmK Ce"+, selective exposure was performed with a laser light of a wavelength corresponding to this absorption. 1 at about 600'Q after baking
The glass plate PG was heated for a period of time to effect crystallization. In order to make the surface of this glass plate PC even smoother, approximately 0.
．． After polishing to a thickness of 1 nm, the opposite side of the polished surface is further coated with a resin, and the glass plate PC is heated to approximately 5% H.
Etching was performed while immersing in an F aqueous solution and applying ultrasonic waves.

Incidentally, in this etching, the etching rate of the crystallized part in the glass plate PC is sufficiently faster than that of the amorphous part, and in fact, the difference in the bifurcating rate of 20: was there.

By the above process, a predetermined number of long grooves LV having a cross section of 50 μm and a width of 50 μm were formed on the glass plate PGVcU as shown in FIG. The groove LV is not limited to the embodiments described above, but can be freely formed with a cross-sectional area of 10 μm x 10 μm to 150 μm x 150 μm and a pitch of 30 μm to 200 μm by adjusting the exposure optical system etc. It is possible to do so.

Next, the glass plate P having the long grooves LV carved in this way is
Epoxy resin as a bonding agent is applied to the grooved surface of G by a dipping method.

At this time, if the glass plate PC is pulled up in a direction parallel to the axis of the groove LV, an uneven coating of epoxy resin can be obtained along the wall surface of the formed groove LV. Thereafter, this coating film was pre-dried at 100'0 for about 5 minutes to semi-cure, and then the glass plate PG was cut into a predetermined size to obtain Part A. Note that the bonding agent is not limited to the above-mentioned epoxy resin. The bonding agent used here is a material that produces a bonding effect when heated, such as epoxy resin adhesive, phenol resin adhesive, urethane resin adhesive, silicone resin adhesive, triazine resin, BT resin, etc. Examples include organic compound adhesives, molten silver salts described in Japanese Patent Publication No. 38-20227, and inorganic compounds such as low-melting glasses. Among these, the latter inorganic compounds are often used in the form of powder rather than liquid. Separately, component B as shown in FIG. 1) is also prepared. This part B is shown in Fig. 2 and Fig. 1 [
As shown in the cross-sectional view taken along the X-Y line of BL, there is a heat storage layer on one side of a substrate (thickness, about 0.6fl) made of metal such as ray, alumina, single crystal silicon, aluminum, iron, etc. (sio! Sputtered film 2-3 μm) 2. Heat generating resistor layer (
FIfB, sputtered film 500-100OA) 3. Electrode layer (aluminum evaporated layer 700-800A>4, protective layer (1μm of 5 loz sputtered film) 5. Filler Fii (sputtered film of parylene, silicone, Ta, O, etc.) 6
It is obtained by sequentially laminating the layers and then cutting them into a predetermined size.

At this time, the electrode layer 4 is etched into a predetermined pattern and separated into individual lead electrodes PE and common lead electrodes CE, as schematically shown in a perspective view in FIG. At the same time, a predetermined number of heating resistor layers 3Ili are exposed in a predetermined pattern HT. The width of this heating resistor pattern HT is the width of the groove LV! It is desirable to keep them at the same level.

Further, the protective layer 5 and the sealing layer 6 shown in FIG. 2 are not laminated depending on the case. Thereafter, the substrate 1B is cut into a predetermined size as a component B. Note that when configuring a recording head of a type in which signals are input from outside the groove LV, the component B may be a simple flat plate. Parts A and B created in this way are shown in FIG.
After alignment is performed so that the and heating resistor pattern HT are in corresponding positions, they are placed together. Next, these are heated at about 100°C for 10 minutes to further semi-cure the bonding agent layer (not shown).
Check for clogging υ, etc. No in this check
), after parts A and B are separated, part B is cleaned and reused. Part A will be discarded. Then, if there is no defect (YES), at 100'0 for 50 minutes,
The adhesive layer is completely cured by heating at 180'O for 2 hours. Thereafter, the presence or absence of clogging in the groove LV is checked again, and if there is no defect (YES), the assembled acting block C is moved to the next process.

In the following process, a relay chamber block D related to ink supply as shown in FIG. 4 is assembled.

First, a bonding agent having the following composition was applied to the side plate parts E and E' respectively, and after alignment with the action chamber block C as shown by the arrow in Fig. 4, the bonding agent was heated at approximately 60'0 for 1 minute. The adhesive is heated to semi-cure, and then it is checked to see if there is any misalignment or if the adhesive has flowed into other parts.

If this check is negative, parts E and E' are separated from block C, and then both are cleaned and reused. If there are no defects (YES), 30 at approximately 60'C.
The bonding agent is cured by heating for a few minutes.

Next, after applying a bonding agent to the rear end part F and performing alignment, the bonding agent is semi-cured by heating at approximately 60° C. for 1 minute.
Here, check the same as in the previous process, and if no (No), clean as in the previous process, and if there are no defects (YES), heat at approximately 60°C for 30 minutes to harden the bonding agent. .

Next, after applying GK bonding agent for the top plate parts and aligning, heat at approximately 60°0 for 1 minute to semi-harden the bonding agent, and check the same as in the previous step. If (NO), clean in the same way as the previous process, and if there are no defects (YES)
), the bonding agent is completely cured by heating at about 60°C for 30 minutes and then at about 100°C for 10 minutes.

Next, the tubular parts H and H' are inserted into the predetermined positions of the blocks assembled in step 1, and the gaps are filled with a bonding agent. In this case, the bonding agent must be cured slowly, so it is left at room temperature for 30 minutes.

Next, it is confirmed whether the bonding agent has flowed into the parts H and H' or whether the ink has flowed into the relay chamber.

If this check is negative (No), it is cleaned and reused in the same manner as in the previous step. If there are no defects (YES), heating is performed at about 60° C. for 30 minutes and then at ioo'o for 10 minutes to completely cure.

In this way, the connection of the relay chamber block D to the rear part of the action section block C is completed. After that, the action block C
Among them, the installation end face OF of the discharge orifice OR is polished using polishing sand (Φ1000 or more) to form a smooth surface. Next, during polishing, the thin groove L is removed from the orifice OR.
Cleaning is performed to remove abrasive sand and unnecessary materials that have gotten into the V. Here, the orifice installation end face O
Check whether F is completely flat and whether the inside of the narrow groove LV is completely cleaned. If the polishing is incomplete, re-polish it a little and then clean it. . Confirmation is performed in the same manner, and if no (No), this process is repeated, and if there is no defect (YES), the combined assembly of blocks C and D is dried.

Furthermore, the completed head is bonded to an aluminum plate, and the lead electrodes are connected to a flexible wiring board.Next, a specific example of inkjet recording performed using the recording head obtained above is shown in FIG. The explanation will be given according to an example. In FIG. 4, for convenience of explanation, each component block is depicted in a separated state. However, in reality, as described above, it goes without saying that each component and the blocks are integrated by joining.

First, in this illustrated example, first, through the part
Recording ink is introduced into each action chamber 4. Next, when an electric pulse signal is input to a heating resistor (not shown), a thermal pulse is generated there, and as a result, the state of the ink instantaneously changes. Due to this state change, a pressure wave (acting force) is applied to the ink, and as a result, the ink becomes small droplets and is ejected and flies from the ejection orifice OR provided in communication with the action chamber LV, which causes the ink to eject and fly. Recording is performed by adhering to the recording member shown in the figure.

In fact, when we conducted an ink ejection experiment using the recording head completed as described above using ink with the following composition under the following experimental conditions, stable ink droplets were ejected more than 101 times, and the resulting dots were It was like Y-.

Signal pulse conditions (per heating element) Ink composition Next, another example will be explained. In this embodiment as well, the explanation will be made according to the assembly process of the multi-array recording head.

In FIG. 5, two components I, J for forming the working chamber part of the recording head are depicted in a schematic perspective view. Figure 5 (Maro 1 depicts the parts worker, and Figure 5 fbl depicts the part J.

Component I is created according to the following procedure.

First, a total of five silicon wafers polished to a surface roughness of 0.5 μm or less were prepared, and a predetermined number of #LVs were cut into each of them using a semiconductor chip scrubber cutter. At this time, grooves of different sizes were cut into each silicon wafer.

Specifically, ■ grooves with a cross section of 10 μm square cut at a pitch of 20 μm, ■ 20, grooves with an am square cut at a pitch of 40 μm, ■ 30
40 μm square grooves at 80 μm pitch, (F) 60 μm square grooves at 120 μm pitch.
A plate SP consisting of a total of five silicon wafers each cut at a μm pitch was created. Then, each play) SP is cut to a predetermined size and parts are machined [Fig.
l) was obtained.

Separately, a component J is created using a method similar to that described in the illustrations of FIG. 1 1b+ and FIG. 2 above. In addition, here, the above five types of plays) SP groove L V
Heat generating resistor pattern IT corresponding to the shape and size of
A total of 5 parts J (the roughness of this surface is approximately 1
．． It is 0 μm or less. ) was created.

The corresponding parts machining and J obtained in this way are the 6th
As shown in the figure, each groove LV and the heating resistor pattern HT are aligned so that they are in corresponding positions, and then layered on each other. Thereafter, as shown in the figure, the laminated parts I and J are sandwiched between arbitrary flat plates PP, , PP and tightened from both sides, whereby both parts are properly fixed.

At this time, since both parts are extremely thin and easily damaged, care must be taken to adjust the tightening pressure appropriately.

In this way, 50P e e/Tomo H25Pe
l! /” +16.7Pee/11m, 12.5
Pe//m, 8.3 Pe/? / cage density, a total of five action block K having #LV serving as an ink flow path was constructed.

Thereafter, after assembling the recording head in the same manner as described in connection with the fourth example shown in FIG.

In the head of the present invention, the information signal human power means is not limited to the electrical/thermal converter represented by the heating resistor as shown in the above illustration, but may be replaced with a piezo vibrator, for example. , or other means capable of inputting thermal energy to the ink may be substituted. As an example, a radiation irradiation means (not shown) may be used in place of the electric/thermal converter. Among these, (semiconductor) laser irradiation means is particularly preferred because of its advantages such as high heat conversion efficiency, ease of transmission, supply, and control, and ability to reduce the size of the device.

As described above, in the type of laser irradiation in which a signal is applied to the ink, it can be performed from outside the ink flow path, so there is an advantage that the internal structure of the head is extremely simplified.

According to the present invention explained in detail above, great effects can be obtained as described below.

In other words, in the present invention, the fC recording head has excellent ink ejection characteristics, that is, ink droplet generation efficiency, energy consumption rate, stability of ink droplet generation, uniformity of generated ink droplets, and responsiveness to input No. 46. In addition, precision machining can be easily performed, and a high-density multi-layered recording head can be obtained by a simple procedure. Further, the recording head of the present invention is capable of forming extremely stable ink droplets during continuous ejection at high speed.

[Brief explanation of drawings]

FIG. 1 (BL, FIG. 2, FIG. 3, and FIG. 4 are explanatory diagrams of one embodiment of the head assembly process of the present invention,
FIG. 5(a), FIG. 1b+, and FIG. 6 are explanatory diagrams of other embodiments of the present invention. In the figure, 1 is the substrate, 3 is the heating resistor layer, and 4 is '1! Pole layer, PG is photosensitive glass plate, HT is heating resistor pattern, CE,
PE is the lead electrode, LV is the groove, OR is the discharge orifice,
SP is a silicon wafer plate, pp, , pp are flat plates, A, B, E, EE', F, G, H, I, I, J are component parts, and C and D are building blocks.

Claims (1)

[Claims] It has a flow path for recording liquid consisting of pores, and from an ejection port communicating with the pores, the recording liquid present in the flow path is ejected into small droplets and made to fly, and the droplets are directed to a recording surface. A recording head that performs recording by adhering the ejection ports, wherein a predetermined number of the ejection ports are arranged in parallel, and the same number of the pores are arranged in parallel at substantially the same density as the arrangement density of the ejection ports. A recording head characterized by: