JP2003136714A - Liquid ejection head and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid ejection head capable of highly reliable high speed ejection comprising a high density multi-nozzle long head in which corrosion resistance of an ejection liquid pressure chamber is enhanced. SOLUTION: The liquid ejection head comprises a diaphragm provided with a piezoelectric element, a nozzle plate having a nozzle hole and a liquid pressure chamber surrounded by a barrier wall wherein the barrier wall is composed of a corrosion resistant metallic material, e.g. SUS, an Ni alloy or a Cu alloy, and the diaphragm is composed of an oxide of metallic material, e.g. ZrO2 , Al2 O3 , MgO, TiO2 , Ta2 O5 , Nb2 O5 , or the like. Corrosion resistance of the pressure chamber is enhanced, a long high density multi-nozzle liquid ejection head can be manufactured readily, and highly reliable high speed ejection is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid ejection head and a method of manufacturing the same, and more particularly to a liquid having a large number of nozzles and a long length, and at the same time, having high corrosion resistance of a liquid pressure chamber and capable of high-reliability and high-speed printing. The present invention relates to a discharge head and a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, with the development of information-oriented society, remarkable progress has been made in miniaturization and high precision of equipment used in information equipment. Higher density and higher definition are also required for the performance of a typical liquid ejection device. Since this inkjet printer can obtain high-definition print output, the apparatus main body is small and lightweight, and the price is relatively low, it has become the mainstream of liquid ejection apparatuses today.

It is no exaggeration to say that the quality of the ink jet printer output largely depends on the performance of the ink jet printer head (hereinafter referred to as the head), and the mounted head influences the performance of the ink jet printer device. In particular, as the image quality becomes higher, one ink droplet becomes finer, and a large number of ink droplets must be ejected to form one screen with this fine ink, and in this case, the printing speed becomes a major issue. Inkjet printers include a piezoelectric method in which the vibration plate of the ink pressure chamber filled with ink is deformed by a piezoelectric element and ink drops are ejected by the pressure, and the heat of a heater installed in the ink chamber causes bubbles in the ink. A bubble jet method for generating ink and ejecting ink droplets, and an electrostatic method for attracting ink and ejecting ink droplets by the electrostatic force of electrodes installed in the ink liquid chamber have been proposed. Has been attracting attention.

FIG. 6 shows a typical configuration example of a piezoelectric ink jet printer. This configuration diagram is shown in Japanese Patent Laid-Open No. 10-
The inkjet printer 100 is configured to include an inkjet printer head 101, a main body 102, a tray 103, and the like. The inkjet printer head 101 is configured to be driven in the direction of the arrow in the drawing when the paper 105 is fed, and to print on the paper 105 with ink droplets ejected from its nozzle (not shown). Has been done. The main body 102 includes a tray 103, and the inkjet printer head 101 is provided inside the tray 103.
Are arranged so that they can be driven. Further, when print information is transmitted from a computer (not shown), the inkjet printer head 101 prints on the paper 105 supplied from the tray 103, and the printed paper can be discharged to the discharge port 104. . The tray 103 is a sheet of paper 10.
5 is a table on which the sheet 105 is placed and the sheet 105
It is configured to be able to supply into 02.

However, as the image quality becomes higher, one ink droplet becomes finer, and a large number of ink droplets must be ejected to form one screen with this fine ink droplet.
In this case, the printing speed becomes a big issue. Therefore, a method of ejecting ink droplets from a large number of nozzles at the same time is a solution to the problem of high-speed printing. Therefore, in the current inkjet printer head, a large number of nozzles are arranged in the direction of the arrow in the drawing and arranged in high density (for example, 48 Nozzle / row, 130d
pi) Further, a head in which 4 to 6 sets of this set are arranged in the direction perpendicular to the arrow to form a multistage structure is generally used.
However, since the total length of the head in the arrow direction is short and the number of nozzles is only 48 nozzles, the head is forced to reciprocate in the arrow direction, which limits the printing speed. Therefore, if the total length of the head can be increased, the movement in the arrow direction is reduced and high-speed printing becomes possible. For example, the short side dimension of A4 size, which is the most frequently used printing paper, 2
If a head corresponding to a length of 10 mm is used, the movement in the direction of the arrow becomes minute and the printing speed is dramatically improved.

The structure of the head portion in a piezoelectric ink jet printer is an ink liquid chamber containing ink and the like, a piezoelectric element as a driving force source when ejecting ink from a nozzle toward recording paper, and an ink ejection nozzle. The ink replenishment mechanism including is the three main constituent requirements. As a typical inkjet printer, Japanese Patent Laid-Open No. 10-2
FIG. 7 shows the configuration described in Japanese Patent No. 64384. Although the ink liquid chamber and the peripheral portion of the piezoelectric element as the actuator are shown in the figure, the head is actually provided with an ink supply mechanism and the like. The ink liquid chamber 10 in FIG. 7 has a structure in which it is partitioned by a partition wall 11 and is covered with a vibration plate 12 and a noise plate 16 from above and below. However, in the actual structure, the partition wall 1
Although an ink replenishing mechanism is configured between the nozzle 1 and the nozzle plate 16, it is omitted in the drawing for the sake of simplicity of description. A piezoelectric film 13 is arranged directly above the ink liquid chamber via a vibration plate,
The piezoelectric element 131 is configured with the lower electrode 14 and the upper electrode 15 of the piezoelectric film. When a voltage is applied between the two electrodes, the piezoelectric element 131 deforms and distorts the diaphragm.
At this time, since the ink liquid chamber is filled with ink or the like, the volume of the ink liquid chamber changes due to the deformation of the vibrating plate, and the ink is supplied to the nozzle 161 provided on the noise plate.
And is pushed out of the ink liquid chamber. The ejected minute ink droplets are attached after reaching the recording paper.

In the above-mentioned known technique, a silicon substrate having a thickness of about 200 μm is used for forming the ink liquid chamber. According to the manufacturing method described, after forming an oxide film on the surface of a silicon substrate, a lower electrode, a piezoelectric layer, and an upper electrode film are sequentially laminated and patterned into a required dimension to form a piezoelectric element. Further, a cavity of the ink liquid chamber is punched on the back surface of the silicon substrate by anisotropic etching. As is clear from the manufacturing process, the partition walls are made of silicon, the diaphragm forming the ceiling part is made of silicon oxide film, and both the partition walls and the diaphragm have an integrated structure, but the nozzle plate on the floor side is fixed with an adhesive or the like. It Since this diaphragm has a thickness of about 10 μm, it takes a considerable amount of time to form an oxide film on the silicon substrate, and high manufacturing technology and management are required to control the variation to a predetermined thickness. It is necessary and has become a manufacturing problem.

On the other hand, in JP-A-6-40035 and JP-A-7-148921, a piezoelectric element is formed by a screen printing method after an ink liquid chamber is laminated and formed by ceramic green sheets such as zirconia and integrally fired. An inkjet printer head provided with is proposed. Since the ink liquid chamber in this case is made of zirconia ceramics, the ink liquid chamber has excellent corrosion resistance, but due to the restrictions of the manufacturing method, the head cannot be miniaturized (high density molding of the ink liquid chamber) and lengthened. Have difficulty. That is, according to the description of Japanese Patent Application Laid-Open No. 7-148921, the ink chamber is formed by laminating and press-bonding three kinds of zirconia grin sheets and then firing and integrating them at a temperature of 800 ° C to 1500 ° C or more. However, the ink liquid chamber is one of the three types of green sheets, which is formed in a sheet located in the middle, and has a minimum processing dimension of about 100 μm, which limits the high density of the ink liquid chamber. Moreover, the dimensional reproducibility of the total length due to firing shrinkage of ceramics is
The limit is about 0.5%, and the total length of the ceramics sintered body is at most 12 to 13 m considering the reproducibility of the positions of the ink chamber and the nozzle and the warpage during sintering of the ceramics sintered body.
It is clear that the limit is about m and that a long head of 200 mm or more cannot be produced.

Further, in the manufacturing method described in JP-A-10-264383, the surface of the ink liquid chamber is 0.2 μm.
There is disclosed a technique of covering with a nickel oxide film of about m to improve the corrosion resistance of the ink liquid chamber. The nickel oxide film has hydrophilicity and is particularly excellent in alkali resistance.
Compared with the case of No. 64384, it is possible to prevent corrosion of the silicon partition wall forming the ink liquid chamber from the alkaline ink liquid,
It is said that it is possible to significantly extend the usable period. Further, there is a description that since the inner wall of the ink liquid chamber is chemically inactive, the quality of the ink liquid does not change and a high quality print output can be obtained. In addition, Japanese Patent Laid-Open No.
Japanese Patent Laid-Open No. 000-37877 discloses a technique in which an ink liquid chamber is processed on a metal substrate and then introduced into an oxidizing atmosphere to heat-treat the surface at a high temperature to form an oxidation resistant metal film on the inner surface of the ink liquid chamber. . Like the above-mentioned Japanese Patent Application Laid-Open No. 10-264383, the technology described in this known example is also a method of protecting the ink liquid chamber with a corrosion-resistant film, which not only complicates the manufacturing method but also relates to the life or reliability. There's a problem.

[0010]

The conventional liquid ejecting apparatus typified by an ink jet printer has the above-described configuration. For example, if the ink liquid chamber is made of silicon, the problem of corrosion is reduced. In order to oxidize the silicon surface and use the oxide film as a diaphragm, a high level manufacturing technology is required. Further, a long head exceeding 200 mm can be produced by using a large-diameter silicon wafer, but this leads to high cost. On the other hand, when the ink liquid chamber is made of ceramics such as zirconia, the ink liquid chamber does not corrode. However, it is necessary to sinter the ceramics at a high temperature of several thousand and several hundred degrees, and not only the position of the ink chamber changes due to the variation in shrinkage during sintering, but also the long length of the zirconia ceramics warps during sintering. It is difficult to make a head, and the length of about 10 mm (48 nozzles / row) is the limit of the element length.

Further, if the ink liquid chamber is made of a metal material, it is relatively easy to lengthen the head, but a problem of corrosion newly occurs. In other words, the corrosion of the ink liquid chamber causes a problem such as deterioration of image quality or inoperability. Such a problem is a basic problem to be solved in terms of reliability and life. A close examination of a conventional inkjet printer head reveals the concentration of corrosion in the corners of the ink chamber. The direct cause of the occurrence of corrosion is pinholes, cracks, and corrosion holes originating from film formation unevenness of the corrosion resistant film formed on the inner surface of the ink liquid chamber. As the thickness of the above-mentioned corrosion-resistant film is smaller, defects are more likely to occur in the recesses from the end side closer to the center or from the flat surface. FIG. 8 is an enlarged schematic view of the vicinity of the vibration plate of the ink liquid chamber. Film defect 171 such as pinhole
Occurs mainly around the joint between the diaphragm and the partition. Further, the ink liquid chamber has a fine sectional shape (for example, a height of 0.1
mm, width 0.12 mm, length 3 mm),
Many defects of the corrosion-resistant film 17 occur nearer to the corner than the central part of the ink liquid chamber, further accelerating the above-mentioned state. In addition, there are several hundreds or more ink liquid chambers in one printer, and even if a problem occurs in one of the ink liquid chambers, it cannot be used as an apparatus. As described above, it is considered impossible to uniformly form a corrosion-resistant film in the ink liquid chamber to eliminate pinholes, cracks, or unevenness, but even if a feasible technique is established, it is very difficult. It will take time and cost.

Further, when the corrosion resistant film is made of a metal material different from the partition wall material, due to the difference in ionization tendency between different metals, the metal material having a large ionization tendency is eluted into the ink liquid through the above defects and the performance of the ink liquid is improved. Deteriorate. Further, as this phenomenon progresses, holes are formed in the metal material having a large ionization tendency, and the ink liquid chamber can no longer be formed. Further, also in the case where the diaphragm is an ink liquid chamber composed of a partition wall material or a metal material different from the corrosion resistant film, the same problem as described above will occur. In other words, 2 ink chambers
If it is composed of more than one kind of metal material, the reliability will be significantly reduced. In addition to the problems described above, demands for higher density, longer size, and lower cost for inkjet printer heads are becoming stronger and stronger, and in order to satisfy these conflicting demands at the same time, it is difficult to solve them by an extension of the conventional technology. Yes, there is a need for drastic measures that can solve essential problems.

[0013]

A liquid discharge head of the present invention is a liquid discharge head having a vibrating plate provided with a piezoelectric element, a nozzle plate having nozzles, and a liquid pressure chamber surrounded by a partition, wherein the partition is The vibrating plate is made of a corrosion-resistant metal material, and the diaphragm is made of a metal material oxide. Further, it is desirable that the diaphragm and the partition wall be directly joined without an adhesive or the like.

In the above invention, the metal material oxide is formed by an aerosol type gas deposition method. Further, the corrosion resistant metal material is SUS, N
It is composed of either an i alloy or a Cu alloy, and the metal material oxide is ZrO ₂ , Al ₂ O ₃ , MgO, or TiO 2.
It is characterized by comprising at least one of ₂ , Ta ₂ O ₅ , and Nb ₂ O ₅ . The width of the partition wall is 10 μm.
To 50 μm, and the thickness of the diaphragm is 1 μm
It is desirable to be in the range of m to 20 μm. The width of the partition wall refers to the dimension of the wall thickness of the partition wall joined to the diaphragm. In addition, the total length of the liquid discharge head is 200 mm to 30 mm.
It is characterized by being in the range of 0 mm. The total length corresponds to the dimension of the liquid ejection head in the arrangement direction of the piezoelectric elements. Further, a reinforcing member is joined to the peripheral portion of the head substrate. The head substrate corresponds to a base body composed of a vibrating plate, a nozzle plate, and partition walls, and the head peripheral portion refers to the vicinity of the outer periphery of the head substrate.

The method of manufacturing a liquid discharge head according to the present invention is a method of manufacturing a liquid discharge head having a vibration plate provided with a piezoelectric element, a nozzle plate having nozzles, and a liquid pressure chamber composed of a partition wall. A step of forming a metal material oxide layer on the material and forming a piezoelectric element on the metal material oxide layer; and a step of forming a liquid pressure chamber in the corrosion resistant metal material plate. . Further, it is preferable that the method further includes the step of forming the metal material oxide layer by an aerosol gas deposition method.

(Function) In the present application, in order to improve the corrosion resistance of the ink liquid chamber and at the same time realize a liquid ejection head having a long head with multiple nozzles and capable of high-speed printing, first, the ink liquid chamber In order to improve the corrosion resistance of the ink chamber, we examined not only the conventional method of using a corrosion resistant protective film but also the method of making the ink chamber itself corrosion resistant, and at the same time, the composition and material of the ink chamber suitable for multiple nozzles and elongated heads. And the present invention has been completed. Next, the technical idea and the solving means of the present invention will be described in detail.

As a result of investigating various configurations in forming the partition wall and the vibration plate which form the ink liquid chamber, in consideration of the reliability regarding corrosion, the ease of carrying out the manufacturing process, and the securing of the processing accuracy, first of all, A composite substrate composed of two layers (or a plurality of layers) constituting the partition wall and the diaphragm is prepared.
Then, it was found that the next step using this composite substrate as a starting material, for example, a method of processing the composite substrate to form an ink liquid chamber or a method of forming a piezoelectric element on the composite substrate was found to be most suitable. Naturally, the point of the present invention is to bond the layers of the composite substrate by direct bonding without using an adhesive or the like. If the adhesive is interposed between the layers, not only the performance will vary, but also the reliability of the liquid ejection device cannot be improved due to the complicated structure.

In the prior art, the partition walls of the ink liquid chamber and the vibrating plate are plates made of different materials, and they are first processed in different steps and then attached to each other.
As described in Japanese Patent No. 264384, a method of modifying a part of a substrate and diverting the modified layer to a diaphragm has been adopted. The former method requires precision in the bonding process, and has a problem in reliability regarding the bonding material. On the other hand, the latter method has excellent corrosion resistance and has the feature that selective etching can be used for perforating the ink liquid chamber, but the silicon single crystal is expensive and has a problem in lengthening. In addition, JP-A-6-40035
In the ink liquid chamber of the zirconia ceramics structure described in Japanese Patent Laid-Open No. 7-148921 and Japanese Patent Application Laid-Open No. 7-148921, the positional accuracy of the ink liquid chamber fluctuates due to variations in shrinkage rate during sintering, which makes it difficult to increase the length.

In the present invention, a method of forming a composite substrate by applying a technique of directly joining different kinds of materials, and forming an ink liquid chamber or the like on the composite substrate by perforation or forming a piezoelectric element is adopted. . That is, the present invention provides a constitution and performance which have not been obtained by applying the composite substrate to the liquid ejection head. Further, in the configuration of the present invention, the thickness of the diaphragm is set to 1 μm in order to ensure the bonding of the diaphragm and the partition wall.
m to 20 μm, preferably 1 μm to 10 μm
It has been found that when the thickness is within the range of m, the manufacturing can be performed with high yield. The reason why the thickness is preferably 10 μm or less is considered to be due to the film thickness uniformity of the metal material oxide forming the diaphragm. On the other hand, in order to efficiently transmit the vibration energy of the piezoelectric element to the diaphragm, it is desirable that the thickness of the diaphragm be substantially equal to the thickness of the piezoelectric element. From this viewpoint, the upper limit of the thickness of the diaphragm is set to the upper limit of the piezoelectric element. The thickness was set to 20 μm in consideration of the thickness setting. The width of the partition wall is in the range of 10 μm to 50 μm, preferably 20 μm
It was also found that it is preferable to set the thickness within the range from 40 μm to 40 μm. This is because when the wall thickness is smaller than 10 μm, pressure crosstalk occurs between the adjacent ink liquid chambers, and the printing characteristics are extremely deteriorated. When the wall thickness is 50 μm or more, the ink liquid chamber has a large dimensional pitch. It becomes impossible to achieve high density.

In the manufacturing method of the present invention, when the liquid pressure chamber is perforated in the corrosion resistant metal material plate, the metal material oxide layer functions as a stopper for perforation (or etching). It is possible to accurately form the dimension in the direction (that is, the length direction of the partition wall).

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a configuration diagram of a main part for explaining an embodiment of a head part of a liquid ejection device according to the present invention. In the figure, 11 is a partition of an ink liquid chamber made of a corrosion-resistant alloy material, 12 is a diaphragm made of a metal oxide, 13 is a piezoelectric material, and 14 and 15 are lower electrodes and upper electrodes for driving the piezoelectric material, respectively. Is. Partition of ink chamber 1
No. 1 is made of a metal material that is resistant to the maximum temperature during the manufacturing process and is excellent in corrosion resistance against ink, and is excellent in piercing processability of the ink liquid chamber, such as SUS, Ni alloy or Cu.
Alloys are preferred. Similar to the partition wall 11, the vibration plate 12 is not particularly limited as long as it is a metal material oxide that can withstand the maximum temperature during the manufacturing process and has excellent corrosion resistance to ink, but the film formation is easy. ZrO ₂ , Al ₂ O
₃ , MgO, TiO ₂ , Ta ₂ O ₅ or Nb ₂ O ₅
Either is desirable. The piezoelectric material 13 includes barium titanate or a lead-free material group having a tungsten bronze structure, etc., but a lead-based piezoelectric ceramic having good deformation efficiency by applying an electric field,
Particularly, lead zirconate titanate Pb (Zr, Ti) O ₃ so-called PZT ceramics is preferable. Also, the electrode 14
And 15 are preferably platinum alloy films (for example, platinum-rhodium alloys) or platinum-titanium, chromium-gold, etc., which are difficult to react with the lead element of the lead-based piezoelectric material at the maximum temperature during the manufacturing process, and more preferably strontium ruthenium. An oxide conductive material such as an oxide may be used. Hereinafter, examples will be described in detail.

First, the composite substrate will be described. As a substrate material for the partition wall of the ink liquid chamber, a corrosion-resistant metal material (for example, SUS plate) that is inexpensive, has a large area required for lengthening, and is easily available, and is easy to perforate is selected. A metal oxide serving as a vibration plate is directly formed thereon by an aerosol gas deposition method or a sol-gel method to form a composite substrate. These manufacturing methods will be briefly described here, and will be specifically described in detail in Examples.

FIG. 2 shows a process of forming an ink liquid chamber and a piezoelectric element of an ink jet printer head using a composite substrate. First, (a) selecting the corrosion resistant metal material substrate 1,
(B) The metal material oxide 2 (which eventually becomes the vibrating plate 12) is formed on this substrate by a method such as an aerosol gas deposition method or a sol-gel method, and the composite substrate 100 is prepared. (C) The electrode 4 (as a result, the lower portion or the common electrode 14) is sequentially formed on the composite substrate by a normal sputtering method.
The piezoelectric film 3 (as a result, the piezoelectric portion 1 of the piezoelectric element 131 is formed by the aerosol gas deposition method or the sol-gel method).
3), the electrode 5 (and consequently the upper electrode 15) is formed.
(D) Next, the piezoelectric film 3 and the electrode 5 are patterned by reactive ion etching (RIE) processing to form the piezoelectric element 131. (E) Further, in order to form the ink liquid chamber 10, the corrosion-resistant metal material substrate is perforated by etching. The ink liquid chamber 10 is perforated at a position corresponding to the piezoelectric element, and at this time, the corrosion-resistant metal material substrate 1 is processed into the partition wall 11. (F) Finally, the ink supply mechanism (not shown) and the nozzle plate 16 having the nozzle 161 are joined.

[0024]

Example 1 As a substrate forming a partition of an ink liquid chamber, a plate thickness is 100 μm, a long side is 110 mm, and a short side is 33 m.
A rectangular SUS304 of m is selected, and ZrO partially stabilized with yttria over almost the entire area of one side of this SUS plate.
Approximately 1 particle of ₂ by aerosol type gas deposition method
It was formed to a thickness of 0 μm. Regarding the aerosol gas deposition method, refer to "Journal of Applied Physics Vol. 68, No. 1".
No. ”on page 44 (1999) and Japan Society for the Promotion of Science Amorphous and Nanomaterials 147 Committee 65th Research Group Sample 3
A detailed explanation is given in the literature on page 1 (October 12, 1999). FIG. 3 schematically shows the principle of the aerosol gas deposition method. When blowing a carrier gas such as argon into ZrO ₂ powder ultrafine state of aerosolized chamber (raw material powder), ZrO ₂ rolled up into a gas
The fine particles of (3) are sprayed with a carrier gas through a spray nozzle onto a SUS substrate installed in a substrate holder of a vacuum film forming chamber at high speed to form a ZrO ₂ film (deposited film). During formation, the position of the spray nozzle with respect to the substrate holder is moved by moving the substrate holder on the stage. At this time, in the case where the ZrO ₂ powder is ultrafine particles having a particle size of 1 μm or less, the film formation rate is increased and at the same time the adhesion strength with the substrate is improved. Further, after sintering in air at 600 ° C. for 1 hour, a Ti film (about 0.1 μm) is formed as a lower electrode 14 on the ZrO ₂ film 12 by sputtering.
m) and a Pt film (about 0.3 μm) are laminated and deposited on almost the entire surface of the ZrO ₂ film 12. Further, a PZT film 13 is formed thereon to have a thickness of about 10 μm by an aerosol gas deposition method similar to the method for manufacturing the ZrO ₂ film,
Heat treatment is performed at 500 ° C. for 1 hour to obtain a desired PZT film.

Next, as a patterning treatment of the PZT film, first, a mask material having a desired shape on the upper surface of the PZT film, for example, a liquid film such as a liquid resist by a photolithography method, a resin film such as a film resist, or an N by a sputtering method.
A metal film of i, Cr or the like is formed. The mask-formed product is fixed to a stage of an RIE (reactive ion etching) apparatus, and PZT is selectively removed by etching in a gas atmosphere of CF4 and CF6. The etching rate varies depending on various conditions such as the atmospheric gas inside the chamber, but PZ is performed at a rate of 0.15 to 0.5 μm / min.
The T is etched, and the etching is stopped by the underlying Ti film or Pt film on which the PZT is formed.

After the PZT etching is completed as described above,
The liquid resist is filled between the PZTs, the resist on the upper surface of the PZT is removed by the squeegee method, and ultraviolet rays are applied to the contact aligner to fix the resist filled between the PZTs. After the above process is completed, an electrode 15 is formed on the upper surface of PZT.
Cr film (0.05 μm) and Au film (0.3 μm)
m) is laminated with PZT over the entire surface of the resist. After that, the resist and the one laminated on the resist upper surface are removed and washed by immersing in a resist stripping solution (such as an alkaline solvent) and brushing. The shape of the island-shaped patterned piezoelectric element is shown in FIG. 4 as a top view seen from the piezoelectric element side. Here, the size of one rectangular piezoelectric element is, as shown in FIG. 4A, for example, the short side w1 is 60 μm and the long side w2 is 2 mm.
Then, about 1250 short sides w1 are formed in the long side direction (110 mm) of the SUS plate at a pitch p1 (for example, 85 μm), and similarly 2 mm in the short side direction (33 mm) of the SUS plate.
5 long sides w2 are formed with a pitch p2 (for example, 5 mm). After perforating the ink liquid chamber (liquid pressure chamber) shown below, it is cut into a size of 110 mm × 5 mmn as shown in FIG. Alternatively, the figure (a) may be used as it is as a head of five stages (five rows). However, in this case, if the pitch p2 is smaller than 5 mm, the head can be downsized.

The patterning formation of the PZT film is as follows.
After forming a PZT film on almost the entire surface of the ZrO ₂ film 12, RIE is performed.
Each of them was patterned into an independent shape by the method described above, but a desired PZT film was directly formed on the ZrO ₂ film 12 by using a mask having an opening at the time of forming the PZT film by the aerosol gas deposition method. It is also possible to deposit the upper electrode 15 (Cr + Au) after the heat treatment, in which case the process is simplified. Also, after forming a Ti film (about 0.1 μm) and a Pt film (about 0.3 μm) as the lower electrode 14 over the entire surface of the ZrO 2 film 12 by sputtering, a resist film pattern is formed on the surface of the electrode in a desired shape. After molding by the photolithography method, a PZT film having a thickness of about 10 μm is formed by the aerosol gas deposition method, and the upper electrode 15 (Cr + Au) is further formed thereon. Then, the resist is removed by a resist stripping solution (alkaline solvent or the like) and washed. After that, it is also possible to perform heat treatment at 500 ° C. for 1 hour to characterize the PZT film formed above.

Next, a SUS plate was perforated to form an ink liquid chamber (liquid pressure chamber). First, a photoresist is applied to one surface of the SUS plate (opposite surface on which the PZT film is formed), dried, exposed, developed and etched using an emulsion mask, and finally the photoresist is peeled off to remove PZT. An ink liquid chamber was created at a predetermined position corresponding to the film. The perforated portion of the ink liquid chamber has a substantially rectangular shape, the long side dimension is about 1 to 3 mm, and the short side dimension is about 0.04 to 0.15.
mm. In addition, the opening diameter (0.02 to 0.07 mm) of the photomask is designed so that the wall thickness of the partition wall portion is 0.03 to 0.08 mm in the short side direction of the perforated portion, and the etching solution (ferric chloride is used). Liquid spray pressure (0.5-5 kgf / cm
² ) was adjusted. In the above examples, the ZrO ₂ film was used as the vibration plate 12, but Al ₂ O was used instead of the ZrO ₂ film.
_A similar head can be produced by using a film of ₃ , MgO, TiO ₂ , Ta ₂ O ₅ , and Nb ₂ O ₅ , and Ni alloy and Cu alloy are used instead of the corrosion-resistant metal material SUS304. Even if it used, the head which was almost the same could be produced.

(Embodiment 2) FIG. 5 is a top view of the essential structure of a liquid ejection head portion of another embodiment according to the present invention as viewed from the piezoelectric element side. The configuration of this example is substantially the same as that of the example 1, and the embodiments partially overlap, so only the main differences will be described. Particularly, in this embodiment, the total length of the head was lengthened in the range of 200 mm to 300 mm, and a reinforcing member was joined to the peripheral portion of the SUS substrate to prevent warpage of the head. The details will be described below.

The top view shown in FIG. 5A corresponds to FIG. 4A shown in the first embodiment. The difference from FIG. 4A is that the long side of the SUS substrate is 200 mm to 300 mm. The point is that the reinforcing member is joined to the peripheral portion of the SUS substrate in order to prevent the bending (warpage or bending) of the entire head from being elongated in the range. That is, as shown in FIG.
A reinforcing member made of a SUS thick plate was installed in the peripheral portion of the SUS plate, and a head portion was prepared in the same process as in Example 1. A substrate having a thickness of 100 μm and a long side of 23 is used as a substrate forming the partition of the ink liquid chamber.
Rectangular SUS30 with 0 mm to 330 mm and short side 33 mm
As in Example 1, ZrO ₂ fine particles partially stabilized by yttria were formed in a thickness of about 10 μm by the aerosol gas deposition method over almost the entire area of one surface of the four plates. Further, a lower electrode and a piezoelectric film PZT were formed, and after patterning into a predetermined shape, an upper electrode was formed. Further, after heat treatment at 500 ° C. for 1 hour, the SUS plate was perforated to form an ink liquid chamber. The reinforcing member is shown in FIG.
As shown in Fig. 5, the reinforcing member was fixed with screws using the screw holes provided in the periphery of the SUS plate. However, if the structure is such that the SUS plate is sandwiched by the reinforcing members as shown in Fig. 5 (c), a stronger reinforcement can be achieved. The effect is obtained.

In the present embodiment, the SUS thick plate was used as the reinforcing member, but a metal other than SUS or ceramics such as alumina or the like is sufficient as the reinforcing member as long as the material has mechanical rigidity and can withstand the heat treatment process of the manufacturing process. Can be used. The reinforcing member may be removed and only the head portion may be attached to the liquid ejecting apparatus, but if it is built in the liquid ejecting apparatus as it is, the process can be further simplified.

[0032]

According to the present invention, it is possible to solve the problem of corrosion of the ink liquid chamber, which has been a problem in the past, and to provide a highly reliable liquid ejection head. Further, the structure is suitable for a multi-nozzle, long head and the cost can be reduced by simplifying the manufacturing process. Furthermore, as an application other than the printer, the method can be opened to the use as a gene analysis device, a flat display device, a medical analysis device, or the like. Further, according to the method of manufacturing the liquid discharge head of the present invention, the liquid discharge head of the present invention can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a main part configuration diagram showing an example of a liquid ejection head unit according to an embodiment of the present invention.

FIG. 2 is a process drawing showing a process of forming a liquid ejection head unit according to an example of the present invention.

FIG. 3 is a schematic configuration diagram of a main part for explaining a configuration diagram of a gas deposition apparatus.

FIG. 4 is a top view of the main configuration of a liquid ejection head unit according to an embodiment of the present invention.

FIG. 5 is a top view of the main configuration of a liquid ejection head unit according to another embodiment of the present invention.

FIG. 6 is a main part configuration diagram for explaining a representative configuration example of a conventional inkjet printer.

FIG. 7 is a main part configuration diagram showing an example of a head unit of a conventional inkjet printer.

FIG. 8 is a main part configuration diagram showing an example of a head unit of a conventional inkjet printer.

[Explanation of symbols]

1 ... Corrosion resistant metal material substrate, 2 ... Metal material oxide, 3 ... Piezoelectric film, 45 ... Electrode, 10 ... Ink liquid chamber, 11 ... Ink liquid chamber partition wall, 12 ... Vibration plate, 13 ... Piezoelectric part, 14 ... Lower electrode, 15 ...
.... Upper electrode, 16 ... Nozzle plate, 100 ...
-Composite substrate, 131 ... Piezoelectric element, 161, ... Nozzle.

Continued front page    (72) Inventor Hiroyuki Tsunematsu             6010 Mikkajiri, Kumagaya City, Saitama Hitachi Metals Co., Ltd.             Inside the production system research institute (72) Inventor Kohei Ito             5200 Mikkajiri, Kumagaya-shi, Saitama Hitachi Metals Co., Ltd.             Inside the Advanced Electronics Research Laboratory F-term (reference) 2C057 AF01 AF70 AG44 AP26 AP31                       AP35 AP43 AP51 AP52 AP54                       AQ06

Claims (9)

[Claims] 1. A liquid discharge head having a diaphragm provided with a piezoelectric element, a nozzle plate having nozzles, and a liquid pressure chamber surrounded by a partition, wherein the partition is made of a corrosion-resistant metal material, and the diaphragm is made of metal. A liquid ejection head comprising a material oxide. 2. The liquid ejection head according to claim 1, wherein the vibrating plate and the partition wall are directly joined to each other without an adhesive or the like. 3. The method according to claim 1, wherein
A liquid ejection head, wherein the metal material oxide is formed by an aerosol gas deposition method. 4. The corrosion resistant metal material according to claim 1, which is made of SUS, Ni alloy or Cu alloy, and the metal material oxide is ZrO ₂ or A.
l ₂ O ₃ , MgO, TiO ₂ , Ta ₂ O ₅ , Nb ₂ O ₅
And a liquid discharge head. 5. The liquid according to claim 1, wherein the partition wall has a width of 10 μm to 50 μm, and the diaphragm has a thickness of 1 μm to 20 μm. Discharge head. 6. The liquid ejection head according to claim 1, wherein the total length of the liquid ejection head is in the range of 200 mm to 300 mm. 7. The liquid ejection head according to claim 1, wherein a reinforcing member is bonded to a peripheral portion of the head substrate. 8. A method of manufacturing a liquid discharge head having a vibration plate provided with a piezoelectric element, a nozzle plate having nozzles, and a liquid pressure chamber including a partition wall, wherein a metal material oxide layer is provided on a plate-shaped corrosion-resistant metal material. Formed,
A method of manufacturing a liquid ejection head, comprising: a step of forming a piezoelectric element on the metal material oxide layer; and a step of boring a liquid pressure chamber in the corrosion resistant metal material plate. 9. The method for manufacturing a liquid discharge head according to claim 8, further comprising a step of forming the metal material oxide layer by an aerosol gas deposition method.