JPH11300961A - Ink jet recording head and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance an exclusion volume without lowering head characteristics. SOLUTION: A recording head is equipped with an elastic film constituting a part of the pressure generation chamber 12 communicating with a nozzle orifice, the vibration plate containing a lower electrode 60 provided on the elastic film 50, the piezoelectric layer 70 formed on the vibration plate and the upper electrode 80 formed on the surface of the piezoelectric layer 70 and a piezoelectric element active part 320 is formed on the region opposed to the pressure generation chamber 12. In this case, membrane parts 61 are formed to the peripheral walls on both sides in at least the lateral direction of the region opposed at least to the pressure generation chamber 12 of the vibration plate and a thick-walled part 62 is patterned on the inside of each membrane part 61 and the piezoelectric element active part 320 consisting of the piezoelectric layer 70 and the upper electrode 80 is patterned on the thick-walled part 62 and the width thereof is made narrower than the thick-walled part 62 to enhance an exclusion volume.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure generating chamber which is in communication with a nozzle opening for ejecting ink droplets, which is constituted by an elastic film. The present invention relates to an ink jet recording head that ejects ink droplets by displacement of layers.

[0002]

2. Description of the Related Art A part of a pressure generating chamber which communicates with a nozzle opening for discharging ink droplets is constituted by a diaphragm, and the elastic film is deformed by a piezoelectric vibrator to pressurize ink in the pressure generating chamber to open the nozzle opening. There are two types of ink-jet recording heads that eject ink droplets from a piezoelectric vibrator, one that uses a longitudinal vibration mode piezoelectric vibrator that expands and contracts in the axial direction of the piezoelectric vibrator, and the other that uses a flexural vibration mode piezoelectric vibrator. Has been put to practical use.

In the former method, the volume of the pressure generating chamber can be changed by bringing the end face of the piezoelectric vibrator into contact with an elastic film, so that a head suitable for high-density printing can be manufactured. A complicated process of cutting the piezoelectric vibrators into a comb-tooth shape in accordance with the arrangement pitch of the nozzle openings, and a work of positioning and fixing the separated piezoelectric vibrators in the pressure generating chambers, which complicates the manufacturing process. There is.

On the other hand, in the latter, a piezoelectric vibrator can be formed on an elastic film by a relatively simple process of sticking a green sheet of a piezoelectric material according to the shape of the pressure generating chamber and firing the green sheet. However, due to the use of flexural vibration, a certain area is required, and there is a problem that high-density arrangement is difficult.

On the other hand, in order to solve the latter disadvantage of the recording head, a uniform piezoelectric material layer is formed over the entire surface of the elastic film by a film forming technique as disclosed in Japanese Patent Application Laid-Open No. 5-286131. A proposal has been made in which this piezoelectric material layer is cut into a shape corresponding to the pressure generating chambers by lithography, and a piezoelectric vibrator is formed so as to be independent for each pressure generating chamber.

According to this, the work of attaching the piezoelectric vibrator to the elastic film becomes unnecessary, and the precision of the lithography method is eliminated.
In addition to the fact that the piezoelectric vibrator can be manufactured by a simple and simple method, there is an advantage that the thickness of the piezoelectric vibrator can be reduced and high-speed driving is possible. In this case, the piezoelectric vibrator corresponding to each pressure generating chamber can be driven by providing at least only the upper electrode for each pressure generating chamber while the piezoelectric material layer is provided on the entire surface of the elastic film.

In a recording head using such a flexural mode piezoelectric vibrator, a piezoelectric material layer and an upper electrode are generally patterned on a lower electrode uniformly formed on an elastic film, thereby obtaining a piezoelectric element. A vibrator was formed.
In the case of such a piezoelectric vibrator, calculation characteristics can be obtained, but since the characteristics themselves are insufficient for practical use, there is a problem that the characteristics need to be further improved.

[0008]

In order to solve this problem, a part of the lower electrode near the boundary with the peripheral wall on both sides in the width direction of the pressure generating chamber is removed with the same width as the piezoelectric material layer and the upper electrode. Although a piezoelectric vibrator with an improved excluded volume has been proposed, there is a problem in that it is not possible to actually obtain a calculated characteristic.

This is because the piezoelectric material layer and the lower electrode are processed by the same process using the same mask.
It is conceivable that the piezoelectric material layer is damaged from the side during ion milling, or strong stress acts on the interface between the piezoelectric material layer and the lower electrode by removing the lower electrode, thereby deteriorating the characteristics of the head. Presumed.

Therefore, the present invention has been made in view of such circumstances,
It is an object of the present invention to provide an ink jet type recording head in which the excluded volume is improved without deteriorating the head characteristics, and a method of manufacturing the same.

[0011]

According to a first aspect of the present invention, there is provided an elastic film forming a part of a pressure generating chamber communicating with a nozzle opening, and a lower electrode provided on the elastic film. And a piezoelectric layer formed on the diaphragm, and an upper electrode formed on the surface of the piezoelectric layer, and a piezoelectric active portion is formed in a region facing the pressure generating chamber. In the ink jet recording head, a thin film portion is formed on at least the peripheral walls on both sides in the width direction of at least a region facing the pressure generating chamber of the vibration plate, and a thick portion is patterned inside the thin film portion. The piezoelectric body active portion consisting of the piezoelectric layer and the upper electrode is patterned,
The width of the piezoelectric active portion is smaller than the width of the thick portion.

According to the first aspect, the thin film portion can be formed on the diaphragm without damaging the piezoelectric layer, and the excluded volume can be improved.

According to a second aspect of the present invention, in the first aspect, the displacement in the width direction between one end in the width direction of the thick part and the end of the piezoelectric active part is 2 μm. The above is an ink jet type recording head.

According to the second aspect, damage to the piezoelectric layer is more reliably prevented.

According to a third aspect of the present invention, in the first or second aspect, the widthwise misalignment between one end of the thick portion in the width direction and the end of the piezoelectric active portion is different. And a width of the piezoelectric active portion is 5 to 10% of the width of the piezoelectric active portion.

In the third aspect, damage to the piezoelectric layer is more reliably prevented, and a desired amount of deformation of the diaphragm due to driving of the piezoelectric active section is ensured.

According to a fourth aspect of the present invention, in any one of the first to third aspects, a lead electrode for applying a voltage to the piezoelectric active portion and the upper electrode are provided on an upper surface of the piezoelectric active portion. An ink jet recording head having a contact portion for making a connection with the ink jet recording head.

In the fourth aspect, a voltage is applied to the piezoelectric active section via the contact section.

According to a fifth aspect of the present invention, in any one of the first to third aspects, the piezoelectric layer and the upper electrode constituting the piezoelectric active portion are provided at least at one end in a longitudinal direction of the pressure generating chamber. And an ink jet type recording head which extends from the top to the peripheral wall.

In the fifth aspect, a voltage is applied to the piezoelectric active portion via the upper electrode on the peripheral wall.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the pressure generation chamber is formed on a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric vibrator is formed by film formation and lithography. An ink jet recording head characterized by being formed by a method.

In the sixth aspect, an ink jet recording head having high-density nozzle openings can be manufactured in a large amount and relatively easily.

According to a seventh aspect of the present invention, a lower electrode layer, a piezoelectric layer, and an upper electrode layer are sequentially laminated on an elastic film provided on one surface of a substrate on which a pressure generating chamber is formed, and each layer is patterned. In a method for manufacturing an ink jet recording head in which a piezoelectric active portion including the piezoelectric layer and the upper electrode is formed in a region opposed to the pressure generating chamber, the upper electrode and the piezoelectric layer are connected to the pressure generating chamber. A first step of forming the piezoelectric active part by patterning with a width smaller than the width of the lower electrode, and patterning and removing at least a part of the lower electrode in the thickness direction outside the width direction of the piezoelectric active part. Forming a thick portion that is wider than the piezoelectric active portion and narrower than the pressure generating chamber inside the portion. Lies in the way.

In the seventh aspect, when a part of the lower electrode is removed by patterning, a thick portion wider than the piezoelectric active portion and narrower than the pressure generating chamber is formed, thereby forming the piezoelectric layer. The thin film portion can be formed without damaging the semiconductor device.

According to an eighth aspect of the present invention, in the seventh aspect, when patterning the lower electrode in the second step, an end face in a width direction of the piezoelectric active portion is protected by a resist pattern. A method for manufacturing an ink jet recording head.

In the eighth aspect, the resist pattern prevents the piezoelectric layer from being damaged when the thin film portion is formed on the lower electrode.

A ninth aspect of the present invention is the method of manufacturing an ink jet recording head according to the seventh or eighth aspect, wherein the patterning of each layer is performed by dry etching.

In the ninth aspect, an ink jet recording head can be manufactured relatively easily by dry etching.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments.

(Embodiment 1) FIG. 1 is an exploded perspective view showing an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 shows a sectional structure of one of the pressure generating chambers in the longitudinal direction. FIG.

As shown in the figure, the flow path forming substrate 10 is a silicon single crystal substrate having a plane orientation of (110) in this embodiment. As the flow path forming substrate 10, usually 150 to 3
A thickness of about 00 μm is used.
Those having a thickness of about 0 to 280 μm, more preferably about 220 μm are suitable. This is because the arrangement density can be increased while maintaining the rigidity of the partition wall between the adjacent pressure generating chambers.

One surface of the flow path forming substrate 10 is an opening surface, and the other surface is formed with an elastic film 50 of 1-2 μm in thickness made of silicon dioxide formed by thermal oxidation in advance.

On the other hand, the opening surface of the flow path forming substrate 10 is anisotropically etched on a silicon single crystal substrate,
A nozzle opening 11 and a pressure generating chamber 12 are formed.

Here, in the anisotropic etching, when the silicon single crystal substrate is immersed in an alkaline solution such as KOH, it is gradually eroded and the first (111) plane perpendicular to the (110) plane and the first (111) plane A second (1) which forms an angle of about 70 degrees with the (111) plane and forms an angle of about 35 degrees with the (110) plane.
11) plane, and the etching rate of the (111) plane is about 1/1 compared to the etching rate of the (110) plane.
This is performed using the property of being 80.
By such anisotropic etching, two first (11
Precision processing can be performed based on depth processing of a parallelogram formed by the 1) plane and two oblique second (111) planes, and the pressure generating chambers 12 can be arranged at high density. it can.

In this embodiment, the long side of each pressure generating chamber 12 is formed by the first (111) plane, and the short side is formed by the second (111) plane. The pressure generating chamber 12 is provided on the flow path forming substrate 1.
It is formed by etching until it reaches the elastic film 50 almost through 0. The amount of the elastic film 50 that is attacked by the alkaline solution for etching the silicon single crystal substrate is extremely small.

On the other hand, each nozzle opening 11 communicating with one end of each pressure generating chamber 12 is formed narrower and shallower than the pressure generating chamber 12. That is, the nozzle opening 11 is formed by partially etching (half-etching) the silicon single crystal substrate in the thickness direction. In addition,
Half etching is performed by adjusting the etching time.

Here, the size of the pressure generating chamber 12 for applying the ink droplet ejection pressure to the ink and the size of the nozzle opening 11 for ejecting the ink droplet depend on the amount of the ejected ink droplet, the ejection speed, and the ejection frequency. Optimized. For example,
When recording 360 ink droplets per inch, the nozzle openings 11 need to be formed with a groove width of several tens of μm with high accuracy.

Further, each pressure generating chamber 12 and a common ink chamber 31 described later are connected to each pressure generating chamber 1 of the sealing plate 20 described later.
The ink is supplied from a common ink chamber 31 through the ink supply communication port 21 formed at a position corresponding to one end of the pressure generation chamber 12. Distributed to

The sealing plate 20 is provided with an ink supply communication port 21 corresponding to each of the pressure generating chambers 12 described above, and has a thickness of, for example, 0.1 to 1 mm and a linear expansion coefficient of 300 ° C. or less. , For example, 2.5-4.5 [× 10 ⁻⁶ / ° C.]. In addition, the ink supply communication port 21
Each of the pressure generating chambers 1 is, as shown in FIGS.
It may be one slit hole 21A crossing the vicinity of the second ink supply side end or a plurality of slit holes 21B. The sealing plate 20 entirely covers one surface of the flow path forming substrate 10 on one surface, and also serves as a reinforcing plate for protecting the silicon single crystal substrate from impact and external force. In addition, the sealing plate 20
The other surface constitutes one wall surface of the common ink chamber 31.

The common ink chamber forming substrate 30 forms the peripheral wall of the common ink chamber 31, and is formed by punching a stainless steel plate having an appropriate thickness in accordance with the number of nozzles and the ink droplet ejection frequency. . In the present embodiment, the thickness of the common ink chamber forming substrate 30 is 0.2 mm.

The ink chamber side plate 40 is made of a stainless steel substrate, and one surface of the ink chamber side plate 40 constitutes one wall surface of the common ink chamber 31. In the ink chamber side plate 40, a thin wall 41 is formed by forming a concave portion 40a by half etching on a part of the other surface, and an ink introduction port 42 for receiving ink supply from the outside is punched and formed. ing. The thin wall 41 is for absorbing pressure generated at the time of ink droplet ejection toward the side opposite to the nozzle opening 11, and is unnecessary for the other pressure generating chambers 12 via the common ink chamber 31. Prevents positive or negative pressure from being applied.
In the present embodiment, the ink chamber side plate 40 is made 0.2 mm in consideration of rigidity required at the time of connection between the ink introduction port 42 and an external ink supply means, and a part of the thickness is 0.02 mm.
The thickness of the ink chamber side plate 40 may be 0.02 mm from the beginning in order to omit the formation of the thin wall 41 by half etching.

On the other hand, on the elastic film 50 on the side opposite to the opening surface of the flow path forming substrate 10, for example, a thickness of about 0.5 μm
A lower electrode film 60, a piezoelectric film 70 having a thickness of, for example, about 1 μm, and an upper electrode film 80 having a thickness of, for example, about 0.1 μm are formed by lamination in a process to be described later. (Piezoelectric element) 300 is constituted. Here, the piezoelectric vibrator 300 refers to a portion including the lower electrode film 60, the piezoelectric film 70, and the upper electrode film 80. Generally, the piezoelectric vibrator 30
0 is used as a common electrode, and the other electrode and the piezoelectric film 70 are patterned for each pressure generating chamber 12. Here, a portion which is constituted by one of the patterned electrodes and the piezoelectric film 70 and in which a piezoelectric strain is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion 320. In the present embodiment, the lower electrode film 60 is used as a common electrode of the piezoelectric vibrator 300, and the upper electrode film 80 is used as an individual electrode of the piezoelectric vibrator 300. Absent. In any case, the piezoelectric active portion is formed for each pressure generating chamber.

An insulating layer 90 having electrical insulation is formed so as to cover at least the periphery of the upper surface of each of the upper electrode films 80 and the side surfaces of the piezoelectric film 70. The insulator layer 90 is formed of a material that can be formed by a film formation method or shaped by etching, for example, silicon oxide, silicon nitride, or an organic material, preferably photosensitive polyimide having low rigidity and excellent electrical insulation. Is preferred.

At a part of the insulator layer 90 which covers the upper surface of a part corresponding to one end of each upper electrode film 80, a part of the upper electrode film 80 is exposed for connection with a lead electrode 100 described later. A contact hole 90a is formed. One end is connected to each upper electrode film 80 via the contact hole 90a, and the other end is formed with a lead electrode 100 extending to the connection terminal portion. Lead electrode 100
Are formed so as to be as narrow as possible so as to reliably supply the drive signal to the upper electrode film 80.

Here, a process for forming the piezoelectric film 70 and the like on the flow path forming substrate 10 made of a silicon single crystal substrate will be described with reference to FIG.

As shown in FIG. 4A, first, a silicon single crystal substrate wafer serving as the flow path forming substrate 10 is
Thermal oxidation is performed in a diffusion furnace at 0 ° C. to form an elastic film 50 made of silicon dioxide.

Next, as shown in FIG. 4B, a lower electrode film 60 is formed by sputtering. Pt or the like is preferable as the material of the lower electrode film 60. This is because a piezoelectric film 70 to be described later, which is formed by sputtering or a sol-gel method, has a thickness of 600 to 100 in an air atmosphere or an oxygen atmosphere after the film formation.
This is because it is necessary to perform crystallization by firing at a temperature of about 0 ° C. That is, the material of the lower electrode film 60 must be able to maintain conductivity at such a high temperature and in an oxidizing atmosphere. In particular, when PZT is used for the piezoelectric film 70, the conductivity of the material by diffusion of PbO is increased. It is desirable that there is little change in sex, and Pt is preferred for these reasons.

Next, as shown in FIG. 4C, a piezoelectric film 70 is formed. The piezoelectric film 70 can be formed by sputtering, but in this embodiment, a so-called sol in which a metal organic substance is dissolved and dispersed in a solvent is applied, dried and gelled, and further baked at a high temperature. A so-called sol-gel method for obtaining a piezoelectric film 70 made of an oxide is used. As a material for the piezoelectric film 70, a lead zirconate titanate (PZT) -based material is suitable when used in an ink jet recording head.

Next, as shown in FIG. 4D, an upper electrode film 80 is formed. The upper electrode film 80 only needs to be a material having high conductivity, and many metals such as Al, Au, Ni, and Pt, and a conductive oxide can be used. In the present embodiment, P
t is formed by sputtering.

Next, as shown in FIG. 5, the lower electrode film 60,
The piezoelectric film 70 and the upper electrode film 80 are patterned.

First, as shown in FIG. 5A, the lower electrode film 60, the piezoelectric film 70 and the upper electrode film 80 are etched together to pattern the entire pattern of the lower electrode film 60. Next, as shown in FIG. 5B, only the piezoelectric film 70 and the upper electrode film 80 are etched to form the piezoelectric active portion 32.
0 patterning is performed. Next, as shown in FIG. 5C, the lower electrode film 60 in a region opposed to both sides in the width direction of each pressure generating chamber 12 (in FIG. 5, the pressure generating chamber 12 is not formed yet but is shown by a broken line). Is patterned. In this embodiment,
The pressure generating chamber 12 is wider than the width of the piezoelectric
The remaining portion of the lower electrode film 60 is partially removed by half-etching or the like, leaving a region smaller than the width of the lower electrode film 60, so that the lower electrode film 60 corresponding to the piezoelectric active portion 320 is removed.
The thin film portion 61 having a smaller thickness is formed. That is, by forming the thin film portion 61, the piezoelectric active portion 32 is formed.
A thick portion 62 thicker than the thin film portion 61 is formed on the diaphragm corresponding to 0. By providing such a thin film portion 61, the amount of displacement of the diaphragm due to application of a voltage to the piezoelectric active portion 320 is improved.

After patterning the lower electrode film 60 and the like as described above, preferably, at least the periphery of the upper surface of each upper electrode film 80, and the piezoelectric film 70 and the lower electrode film 60 are preferably formed.
Is formed so as to cover the side surfaces of the substrate (see FIG. 2).

Then, each piezoelectric active portion 3 of the insulator layer 90
A contact hole 90a is formed in a part of the portion corresponding to the vicinity of the end of 20. One end is connected to each upper electrode film 80 through the contact hole 90a, and the other end is formed with a lead electrode 100 extending to a connection terminal portion such as an AFC (anisotropic conductive film).

FIG. 6 shows a process of forming such an insulator layer and a lead electrode.

First, as shown in FIG. 6A, an insulator layer 90 is formed so as to cover the periphery of the upper electrode film 80, the side surfaces of the piezoelectric film 70 and the lower electrode film 60. This insulator layer 9
In this embodiment, 0 is a negative photosensitive polyimide.

Next, as shown in FIG. 6B, by patterning the insulator layer 90, each of the pressure generating chambers 12 is formed.
Contact hole 90a
To form

Next, a lead electrode 100 is formed by depositing a conductor such as Cr-Au on the entire surface and patterning the conductor.

The above is the film forming process. After forming the film in this manner, as shown in FIG. 6C, the silicon single crystal substrate is subjected to anisotropic etching with the above-described alkali solution to form the pressure generating chamber 12 and the like. In addition,
In the series of film formation and anisotropic etching described above, a number of chips are simultaneously formed on one wafer, and after completion of the process, each of the flow path forming substrates 10 having one chip size as shown in FIG. To divide. Further, the divided flow path forming substrate 10 is sequentially adhered and integrated with the sealing plate 20, the common ink chamber forming substrate 30, and the ink chamber side plate 40 to form an ink jet recording head.

FIG. 7 shows a plan view and a cross section of a main part of the ink jet recording head thus formed.

As shown in FIG. 7, in this embodiment, the piezoelectric active portion 32 composed of the piezoelectric film 70 and the upper electrode film 80 is used.
0 is provided in a region facing the pressure generating chamber 12. In the vicinity of the longitudinal end of the piezoelectric active part 320, an insulator layer 9 provided on the piezoelectric active part 320 is provided.
The upper electrode film 80 and the lead electrode 100 are connected via the 0 contact hole 90a.

Further, a thin film portion 61 having a smaller thickness than other portions is formed on the diaphragm in a region opposed to both sides in the width direction of the pressure generating chamber 12. Therefore, the piezoelectric active part 3
As a result, the diaphragm at the portion corresponding to 20
The thick portion 62 is thicker than the thick portion 62.

The thick portion 62 has a width larger than the width of the piezoelectric body active portion 320 and smaller than the width of the pressure generating chamber 12. That is, the thick portion 62 is formed such that one end in the width direction is separated from the one end in the width direction of the piezoelectric film 70 by the distance L. That is, as shown in FIGS. 8A and 8B, when patterning the lower electrode film 60, the both sides in the width direction of the piezoelectric active portion 320 are covered and protected by the resist 110. Thereby, damage to the piezoelectric film 70 when patterning the lower electrode film 60 is suppressed. Therefore,
Distance L between the ends in the width direction of thick portion 62 and piezoelectric film 70
Is at least 2 μm in consideration of the thickness of the resist 110.
m or more. Furthermore, if the distance L is made longer than necessary, the amount of deformation of the diaphragm decreases, and the characteristics of the head deteriorate. Therefore, the distance L is set to
Is preferably 5 to 10% of the width W. For example, in the present embodiment, while W = 30 μm, L = 2
μm.

As described above, by forming the diaphragm corresponding to the piezoelectric active portion 320 as the thick portion 62 having a width larger than the width of the piezoelectric active portion 320, By providing the end in the width direction by a predetermined distance outside the end in the width direction of the piezoelectric active portion 320, when patterning the lower electrode film 60 by ion milling or the like,
Damage to the piezoelectric film 70 from the side surface can be suppressed. Further, the stress acting on the interface between the piezoelectric film 70 and the lower electrode film 60 is suppressed. Further, since the diaphragm in the region opposed to both sides in the width direction of the pressure generating chamber 12 is provided with the thin film portion 61 from which a part of the lower electrode film 60 is removed, the driving of the piezoelectric active portion 320 is substantially performed. As a result, the amount of deformation of the vibration plate is improved. Therefore, the characteristics of the head can be sufficiently improved, and the reliability of the head can be improved.

The ink jet head thus configured takes in ink from an ink inlet 42 connected to external ink supply means (not shown), fills the interior from the common ink chamber 31 to the nozzle opening 11 with ink, and
In accordance with a recording signal from an external drive circuit (not shown), a voltage is applied between the lower electrode film 60 and the upper electrode film 80 via the lead electrode 100, and the elastic film 50, the lower electrode film 60, and the piezoelectric film 70 The pressure generating chamber 1 is deformed by bending.
The pressure in 2 increases, and ink droplets are ejected from nozzle opening 11.

In this embodiment, the thin film portion 61 is formed by partially removing the lower electrode film 60 in the thickness direction without completely removing the lower electrode film 60. However, the present invention is not limited to this.
As shown in FIG. 9A, the lower electrode film 60 may be completely removed. For example, as shown in FIG. 9B, a part of the elastic film 50 may be removed. Is also good.

In this embodiment, all the lower electrode films 60 between the pressure generating chamber 12 and the adjacent pressure generating chamber 12 are partially removed. However, the present invention is not limited to this.
As shown in FIG. 10, the same effect as described above can be obtained by forming the thin film portion 61 only in a region facing at least the vicinity of the end in the width direction of the pressure generating chamber 12.

Further, in the present embodiment, the contact hole 90a is provided at a position facing the pressure generating chamber 12, but for example, as shown in FIG.
Alternatively, the upper electrode film 80 may be extended to the peripheral wall of the pressure generating chamber 12.

(Other Embodiments) The embodiments of the present invention have been described above, but the basic configuration of the ink jet recording head is not limited to the above.

For example, in addition to the sealing plate 20 described above, the common ink chamber forming plate 30 may be made of glass ceramic, and the thin film 41 may be made of glass ceramic as a separate member. Changes are free.

Further, in the above-described embodiment, the nozzle openings are formed on the end surface of the flow path forming substrate 10. However, the nozzle openings protruding in a direction perpendicular to the surface may be formed.

FIG. 12 is an exploded perspective view of the embodiment configured as described above, and FIG. 13 is a cross-sectional view of the flow path. In this embodiment, the nozzle openings 11 are drilled in the nozzle substrate 120 opposite to the piezoelectric vibrator, and these nozzle openings 11
A nozzle communication port 22 for communicating the pressure generating chamber 12 with the pressure generating chamber 12 is provided so as to penetrate the sealing plate 20, the common ink chamber forming plate 30, the thin plate 41A, and the ink chamber side plate 40A.

In this embodiment, the thin plate 41
A is basically the same as the above-described embodiment except that the ink chamber side plate 40A and the ink chamber side plate 40A are separate members, and the opening is formed in the ink chamber side plate 40. Is omitted.

Here, also in this embodiment, as in the above-described embodiment, the width of the thick portion provided on the diaphragm in the region facing the piezoelectric active portion is made larger than the width of the piezoelectric active portion. By making the width wider and smaller than the width of the pressure generating chamber, the characteristics and reliability of the head can be improved.

In the embodiment described above, a thin-film type ink jet recording head which can be manufactured by applying a film forming and lithography process has been described as an example. However, the present invention is not limited to this. Ink-jet recording of various structures, such as forming a pressure generating chamber by laminating, or forming a piezoelectric film by pasting a green sheet or screen printing, or forming a piezoelectric film by crystal growth The present invention can be adopted for a head.

Further, the example in which the insulator layer is provided between the piezoelectric vibrator and the lead electrode has been described. However, the present invention is not limited to this. The conductive film may be thermally welded, and the anisotropic conductive film may be connected to the lead electrode, or may be connected using various bonding techniques such as wire bonding.

As described above, the present invention can be applied to ink-jet recording heads having various structures, as long as the spirit of the present invention is not contradicted.

[0077]

As described above, according to the present invention, a thick part thicker than other parts is provided on the diaphragm corresponding to the piezoelectric active part, and the width of the thick part is reduced. By forming the width wider than the width of the piezoelectric active portion and narrower than the width of the pressure generating chamber, damage to the piezoelectric layer when patterning the lower electrode can be suppressed, and the amount of deformation of the diaphragm can be improved. it can. Therefore, there is an effect that the characteristics of the head can be substantially improved and the reliability can be improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an ink jet recording head according to an embodiment of the present invention.

FIG. 2 is a plan view and a cross-sectional view of the inkjet recording head according to the first embodiment of the present invention, showing the same.

FIG. 3 is a view showing a modification of the sealing plate of FIG. 1;

FIG. 4 is a diagram showing a thin film manufacturing process according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a thin film manufacturing process according to the first embodiment of the present invention.

FIG. 6 is a view showing a thin film manufacturing process according to the first embodiment of the present invention.

FIG. 7 is a plan view and a cross-sectional view illustrating Embodiment 1 of the present invention.

FIG. 8 is a diagram showing a thin film manufacturing process according to the first embodiment of the present invention.

FIG. 9 is a sectional view showing a modification of the first embodiment of the present invention.

FIG. 10 is a sectional view showing a modification of the first embodiment of the present invention.

FIG. 11 is a plan view showing a modification of the first embodiment of the present invention.

FIG. 12 is an exploded perspective view of an ink jet recording head according to another embodiment of the present invention.

FIG. 13 is a cross-sectional view illustrating an ink jet recording head according to another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 flow path forming substrate 11 nozzle opening 12 pressure generating chamber 50 elastic film 60 lower electrode film 61 thin film portion 62 thick portion 70 piezoelectric film 80 upper electrode film 90 insulator layer 100 lead electrode 110 resist 300 piezoelectric vibrator 320 piezoelectric body Active part

Claims (9)

[Claims] 1. A diaphragm including an elastic film constituting a part of a pressure generating chamber communicating with a nozzle opening, a lower electrode provided on the elastic film, and a piezoelectric layer formed on the diaphragm. ,
An ink jet recording head comprising: an upper electrode formed on the surface of the piezoelectric layer; and a piezoelectric active portion formed in a region facing the pressure generating chamber, wherein the inkjet recording head faces at least the pressure generating chamber of the vibration plate. A thin film portion is formed on at least the peripheral walls on both sides in the width direction of the region, and a thick portion is patterned inside the thin film portion, and a piezoelectric active portion including the piezoelectric layer and the upper electrode is patterned on the thick portion, An ink jet recording head, wherein the width of the piezoelectric active portion is smaller than the width of the thick portion. 2. The device according to claim 1, wherein a displacement in a width direction between one end of the thick portion in the width direction and an end of the piezoelectric active portion is 2 μm or more. Ink jet recording head. 3. The piezoelectric active part according to claim 1, wherein a displacement in the width direction between one end of the thick part in the width direction and an end of the piezoelectric active part is the width of the piezoelectric active part. 5-10% of
An ink jet recording head, characterized in that: 4. A contact part for connecting a lead electrode for applying a voltage to said piezoelectric active part and said upper electrode on an upper surface of said piezoelectric active part according to claim 1. An ink jet recording head comprising: 5. The piezoelectric device according to claim 1, wherein the piezoelectric layer and the upper electrode constituting the piezoelectric active part are:
An ink jet recording head extending from at least one end in the longitudinal direction of the pressure generating chamber to a peripheral wall thereof. 6. The pressure generating chamber according to claim 1, wherein the pressure generating chamber is formed on a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric vibrator is formed by film formation and lithography. An ink jet recording head, characterized in that: 7. The pressure generating chamber is formed by sequentially laminating a lower electrode layer, a piezoelectric layer, and an upper electrode layer on an elastic film provided on one surface of a substrate forming the pressure generating chamber and patterning each layer. In a method of manufacturing an ink jet recording head in which a piezoelectric active portion including the piezoelectric layer and the upper electrode is formed in an opposed region, the upper electrode and the piezoelectric layer are patterned with a width smaller than a width of the pressure generating chamber. A first step of forming the piezoelectric body active section, and patterning and removing at least a part of the lower electrode in the thickness direction outside the width direction of the piezoelectric body active section to form a thin film section, Forming a thick portion wider than the piezoelectric active portion and narrower than the pressure generating chamber. 8. The ink-jet method according to claim 7, wherein when patterning the lower electrode in the second step, an end face in a width direction of the piezoelectric active portion is protected by a resist pattern. Method of manufacturing a recording head. 9. The method according to claim 7, wherein patterning of each layer is performed by dry etching.