JPH1177999A - Ink jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording apparatus capable of preventing not only the crack, destruction or the like by the concn. of stress in a contact part but also the lowering of the displacement efficiency of the contact part. SOLUTION: An ink jet recording head includes a piezoelectric vibrator consisting of the piezoelectric element layer 70 formed on the surface of a vibration plate and a piezoelectric element active part composed of the upper electrodes 80 formed on the surface of the piezoelectric element layer 70 and formed on the regions opposed to pressure generation chambers 12 and contact parts 90a are provided in the regions opposed to the pressure generation chambers 12. In this case, a conductor film 100 contains the contact parts 90a in a planar state and is extended to peripheral walls in at least two directions of the pressure generation chambers 12.

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 discharging ink droplets, and which is constituted by a vibrating plate. The present invention relates to an ink jet recording head that ejects ink droplets by displacement of a layer.

[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 vibrating plate. 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 the vibrating plate, 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 a diaphragm by a relatively simple process of sticking a green sheet of a piezoelectric material according to the shape of a 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 by a film forming technique over the entire surface of the diaphragm 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.

[0006] According to this, the work of attaching the piezoelectric vibrator to the diaphragm is not required, and the precision of the lithography method is used.
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 is 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 vibration plate. However, due to the problem of the amount of displacement per unit drive voltage and the stress applied to the piezoelectric layer at the portion facing the pressure generating chamber and the portion straddling the outside thereof, the piezoelectric active portion composed of the piezoelectric layer and the upper electrode is required. It is desirable that the pressure sensor be provided in a region facing the pressure generating chamber or be formed so that at least one end portion does not come out of the region facing the pressure generating chamber.

Further, in a recording head using such a flexural mode piezoelectric vibrator, the piezoelectric vibrators corresponding to the respective pressure generating chambers are covered with an insulator layer, and each of the piezoelectric vibrators is covered with the insulator layer. A window (hereinafter, referred to as a contact hole) is provided corresponding to each pressure generating chamber to form a connection portion with a conductive film for supplying a driving voltage, and each piezoelectric vibrator and the conductive film are provided. Is formed in the contact hole.

[0009]

However, cracks may occur in the piezoelectric layer around the contact portion, probably because the stress generated when the pattern of the conductive film is formed is transmitted to the piezoelectric film via the contact portion. There is a problem that it is easy.

Further, as described above, a large stress is easily generated by driving the piezoelectric vibrator in the contact hole portion where the connection portion between the piezoelectric active portion and the conductive film corresponding to each pressure generating chamber is formed. In addition, there is a problem that the stress of the conductive film acts on the piezoelectric active portion, which may cause cracks, breakage, and the like.

[0011] These problems become particularly problematic when the piezoelectric material layer is formed by a film forming technique. That is, since the piezoelectric material layer formed by the film forming technique is very thin, the rigidity thereof is lower than that of the piezoelectric material layer attached.

In view of such circumstances, an object of the present invention is to provide an ink jet recording head capable of preventing cracks, breakage, and the like due to stress concentration at a contact portion, and preventing a reduction in displacement efficiency of the contact portion. And

[0013]

According to a first aspect of the present invention, a part of a pressure generating chamber communicating with a nozzle opening is formed.
A vibrating plate having at least an upper surface serving as a lower electrode, a piezoelectric layer formed on the surface of the vibrating plate, and an upper electrode formed on the surface of the piezoelectric layer, and formed in a region facing the pressure generating chamber. A piezoelectric vibrator comprising a selected piezoelectric active portion, and a connecting portion between the conductive film for applying a voltage to the piezoelectric active portion and the piezoelectric active portion in a region facing the pressure generating chamber. In the ink jet recording head provided with a contact portion, the conductor film includes the contact portion in a plane and extends to at least two peripheral walls of the pressure generating chamber. In the ink jet recording head.

In the first aspect, the stress of the lead portion is received by the plurality of peripheral walls, and the stress applied to the piezoelectric active portion around the contact portion is reduced.

According to a second aspect of the present invention, in the first aspect, an insulating layer is formed on an upper surface of the piezoelectric active portion;
The contact portion is formed in a contact hole formed in the insulator layer.

In the second aspect, a voltage is applied to the piezoelectric active portion in the contact hole, but the breakage of the piezoelectric layer around the contact hole is prevented.

According to a third aspect of the present invention, in the first or second aspect, the conductive film is wider than the width of the pressure generating chamber and extends from a longitudinal end of the pressure generating chamber to above the contact portion. Provided in the ink jet recording head.

In the third aspect, the stress of the conductor film is received by the plurality of peripheral walls of the pressure generating chamber, and the stress applied to the piezoelectric active portion around the contact portion is reduced.

According to a fourth aspect of the present invention, in the first or second aspect, the conductive film is wider than a dimension of the contact portion along a longitudinal direction of the pressure generating chamber, and is formed on both sides of the pressure generating chamber. An ink jet recording head is formed so as to straddle a wall.

In the fourth aspect, the stress of the conductor film is received by the peripheral walls on both sides in the width direction of the pressure generating chamber, and the stress applied to the piezoelectric active portion around the contact portion is reduced.

According to a fifth aspect of the present invention, in any one of the first to fourth 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 as a film. And an ink jet recording head formed by a lithography method.

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

[0023]

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

(Embodiment 1) FIG. 1 is an assembled perspective view showing an ink jet recording head according to an embodiment of the present invention. FIG. 2 is a plan view and a cross section of one of the pressure generating chambers in the longitudinal direction. It is a figure showing a structure.

As shown in the figure, the flow path forming substrate 10 is formed of a silicon single crystal substrate having a plane orientation (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 having a thickness of 1 to 2 μm and made of silicon dioxide previously formed by thermal oxidation.

On the other hand, the silicon single crystal substrate is anisotropically etched on the opening surface of the flow path forming 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, the substrate is gradually eroded and the first (111) plane perpendicular to the (110) plane and the first (111) plane The second (11) which forms an angle of about 70 degrees with the (111) plane and forms an angle of about 35 degrees with the above (110).
1) plane appears, and the etching rate of the (111) plane is about 1/18 as compared with the etching rate of the (110) plane.
This is performed using the property of being 0. By such anisotropic etching, two first (111)
Precision processing can be performed based on the depth processing of a parallelogram formed by two surfaces and two oblique second (111) surfaces, and the pressure generating chambers 12 can be arranged at high density.

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 to 4.5 [× 10 ⁻⁶ / ° C.]. The ink supply communication port 2
As shown in FIGS. 3A and 3B, 1 is a single slit hole 21A or a plurality of slit holes 21B crossing the vicinity of the ink supply side end of each pressure generating chamber 12. Good. The sealing plate 20 is provided on one side with the flow path forming substrate 10.
, And also serves as a reinforcing plate for protecting the silicon single crystal substrate from impacts and external forces. Also, sealing plate 2
0 forms one wall surface of the common ink chamber 31 on the other surface.

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 according to 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 thereof 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, a thickness of, for example, 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). Thus, the elastic film 50
In the area facing each pressure generating chamber 12, a piezoelectric vibrator is provided independently for each pressure generating chamber 12, but in the present embodiment, the lower electrode film 60 is a common electrode of the piezoelectric vibrator. Although the upper electrode film 80 is used as an individual electrode of the piezoelectric vibrator, there is no problem even if the upper electrode film 80 is reversed for convenience of a drive circuit and wiring. In the present embodiment, the piezoelectric films 70 are individually provided corresponding to the respective pressure generating chambers 12. However, the piezoelectric films are provided entirely, and the upper electrode film 80 is provided corresponding to each of the pressure generating chambers 12. They may be provided individually. In any case, a pressure active portion is formed for each pressure generating chamber 12.

An insulator 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.

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 70 must be able to maintain conductivity at such a high temperature and in an oxidizing atmosphere. In particular, when PZT is used as the piezoelectric film 70, the conductivity due to the diffusion of PbO 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. 5 (c), the piezoelectric active region is a region opposed to both sides in the width direction of each pressure generating chamber 12 (in FIG. 5, the pressure generating chamber 12 has not been formed yet but is indicated by a broken line). By removing portions of the lower electrode film 60 corresponding to the arms of the diaphragm on both sides of the portion 320, a lower electrode film removing portion 350 is formed. Thus, the lower electrode film removing section 3
By providing 50, the amount of displacement due to application of a voltage to the piezoelectric body active section 320 is improved.

It should be noted that the lower electrode removing section 350 is provided with the lower electrode film 6.
The thickness may be reduced without completely removing 0.
Further, the lower electrode removing portion 350 is formed in a portion corresponding to the arm portion of the piezoelectric active portion 320, but is not limited thereto.
For example, it may be formed to the outer side in the longitudinal direction from both ends of the piezoelectric body active portion 320, or may be formed over substantially the entire peripheral portion of the pressure generating chamber 12. Needless to say, the lower electrode removing section 350 is not necessarily provided.

As described above, after patterning the lower electrode film 60 and the like, 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. 1).

Then, each piezoelectric active portion 3 of the insulator layer 90
An upper electrode film 8 is formed on a portion of the portion covering the upper surface of the portion corresponding to one end of the upper electrode film 20 to connect to a conductor film 100 described later.
A contact hole 90a exposing a part of 0 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 conductor film 100 extending to the connection terminal portion.

FIG. 6 shows a process of forming such an insulator layer and a conductor film.

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

Next, as shown in FIG. 6B, by patterning the insulator layer 90, each of the pressure generating chambers 12 is formed.
A contact hole 90a is formed in a portion corresponding to the vicinity of the end on the ink supply side. This contact hole 90a
Is for connecting a conductive film 100 and an upper electrode film 80 described later. The contact hole 90a
May be provided at a portion corresponding to the piezoelectric active portion 320 of the pressure generating chamber 12, and may be provided at, for example, a central portion or a nozzle-side end portion.

Next, for example, a conductor such as Cr-Au is formed on the entire surface and then patterned to form the conductor film 100.

FIG. 7 shows the positional relationship between the thus formed conductive film 100 and the piezoelectric active portion 320.

As shown in FIG. 7, the piezoelectric active portion 320 including the piezoelectric film 70 and the upper electrode film 80 is provided in a region facing the pressure generating chamber 12, and
0 is wider than the width of the pressure generation chamber 12 and the pressure generation chamber 1
2 extends from the longitudinal end to above the contact hole 90a. That is, the conductor film 100 is formed so as to cover regions facing the peripheral walls of the pressure generating chamber 12 in three directions.

With such a structure, the stress generated in the conductive film 100 is received by the plurality of peripheral walls of the pressure generating chamber 12, in this embodiment, the three-directional peripheral walls. Body active part 320
Is reduced, and peeling and cracking of the piezoelectric active portion 320 can be prevented. Further, since the conductor film 100 is formed so as to cover the vicinity of the contact hole 90a, the current flows from the entire outer edge portion of the contact hole 90a to the upper electrode 80, the concentration of current density is reduced, and the insulation caused by migration is reduced. It is considered that destruction and the like can be prevented.

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 such an ink jet recording head, a number of chips are simultaneously formed on one wafer by the above-described series of film formation and anisotropic etching, and after the process is completed, as shown in FIG. The substrate is divided for each of the flow path forming substrates 10 having one chip size. Further, the divided flow path forming substrate 10 is divided into a sealing plate 20 and a common ink chamber forming substrate 3.
0 and the ink chamber side plate 40 are sequentially bonded and integrated to form an ink jet recording head.

The ink jet recording head thus configured takes in ink from an ink inlet 42 connected to external ink supply means (not shown),
After filling the inside with ink from 1 to the nozzle opening 11, according to a recording signal from an external driving circuit (not shown),
A voltage is applied between the lower electrode film 60 and the upper electrode film 80 via the conductor film 100 to cause the elastic film 50, the lower electrode film 60, and the piezoelectric film 70 to bend and deform. Is increased, and ink droplets are ejected from the nozzle opening 11.

(Embodiment 2) FIG. 8 shows a positional relationship between a conductive film and a piezoelectric active portion of an ink jet recording head according to Embodiment 2.

This embodiment is the same as the first embodiment except that the conductive film 100A is patterned so as to extend in two directions, one side wall and one end of the pressure generating chamber 12. In this embodiment, the piezoelectric layer and the upper electrode are provided so as to extend from one end of the pressure generating chamber 12 to the peripheral wall, but this is not directly related to the gist of the present invention.

Therefore, by adopting such a structure, similarly to the first embodiment, the stress generated in the conductive film 100A is received by the plurality of peripheral walls, in this embodiment, the two-directional peripheral wall, and the piezoelectric active portion is formed. The stress applied to the vicinity of the end of 320 can be reduced, and peeling and cracking can be prevented. Further, since the stress of the conductive film 100 is received by the peripheral walls in two directions, a large decrease in the displacement amount of the piezoelectric active portion 320 can be suppressed. Further, the conductor film 1
Since 00 is formed so as to cover the entire vicinity of the contact hole 90a, the current flows from the entire outer edge of the contact hole 90a to the upper electrode 80, so that the concentration of the current density is reduced.

(Embodiment 3) FIG. 9 shows the positional relationship between a conductive film and a piezoelectric active portion of an ink jet recording head according to Embodiment 3.

In this embodiment, the conductive film 100B is formed so as to be wider than the dimension of the contact hole 90a along the longitudinal direction of the pressure generating chamber 12 and to straddle both side walls of the pressure generating chamber 12, and furthermore, both ends thereof The portion is the same as that of the first embodiment except that the portion extends along both side walls. The effects of this embodiment are the same as those of the second embodiment. In this embodiment, a desired high voltage can be easily applied by providing a pattern connected to the outside on both side walls of the pressure generating chamber 12.

(Embodiment 4) FIG. 10 shows a positional relationship between a conductive film and a piezoelectric active portion of an ink jet recording head according to Embodiment 4.

This embodiment is the same as the third embodiment except that the contact hole 90a is formed substantially at the center of the piezoelectric active portion 320 in the longitudinal direction. The conductive film 100C is formed on the upper surface of the contact hole 90a and in the pressure generating chamber. 12 are formed so as to straddle both side walls. Note that the pattern serving as a connection portion with the outside is different from that of the third embodiment and extends along one side wall. However, in other respects, the same effect as that of the third embodiment is exerted.

(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.

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 may be formed to project in a direction perpendicular to the surface.

FIG. 11 is an exploded perspective view of the embodiment configured as described above, and FIG. 12 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, in this embodiment, as in the first to fourth embodiments, the conductive film is formed so as to cover a plurality of peripheral walls of the pressure generating chamber, so that the stress acting on the piezoelectric active portion is increased. And the occurrence of cracks and the like can be prevented.

Of course, the present invention can be similarly applied to an ink jet recording head of a type in which a common ink chamber is formed on a flow path forming substrate.

In each of the embodiments described above, a thin film type ink jet recording head which can be manufactured by applying a film forming and lithography process is described as an example.
Of course, the present invention is not limited to this. For example, a piezoelectric film is formed by laminating substrates to form a pressure generating chamber, or a piezoelectric film is formed by attaching a green sheet or by screen printing, or a piezoelectric film formed by crystal growth. The present invention can be applied to ink jet recording heads having various structures, such as those that form a recording medium.

Further, in each of the above-described embodiments, the elastic film is provided separately from the lower electrode film as the vibration plate, but the lower electrode film may also serve as the elastic film.

Further, the example in which the insulator layer is provided between the piezoelectric vibrator and the conductor film has been described. However, the present invention is not limited to this. For example, without providing the insulator layer, each upper electrode is anisotropically formed. Thermal conductive welding of the conductive film, connecting this anisotropic conductive film to the conductive film,
In addition, the connection may be made 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.

[0076]

As described above, according to the present invention, the stress applied to the conductor film is reduced by forming the conductor film so as to cover the regions facing the plurality of peripheral portions of the pressure generating chamber. And the stress acting on the piezoelectric active portion near the contact hole is reduced, and since the conductive film is formed with a relatively large width, the conductive film in the contact hole is The density of the current flowing into the connection with the upper electrode is reduced, and the occurrence of cracks and the like can be prevented.

[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 illustrating a main part of the ink jet recording head according to the first embodiment of the present invention.

FIG. 8 is a plan view showing a main part of an ink jet recording head according to Embodiment 2 of the present invention.

FIG. 9 is a plan view illustrating a main part of an ink jet recording head according to a third embodiment of the invention.

FIG. 10 is a plan view illustrating a main part of an ink jet recording head according to a fourth embodiment of the present invention.

FIG. 11 is an exploded perspective view of an ink jet recording head according to another embodiment of the present invention.

FIG. 12 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 70 piezoelectric film 80 upper electrode film 90 insulator layer 100 conductor film 320 piezoelectric active part 350 lower electrode removing part

Claims (5)

[Claims] 1. A vibrating plate constituting a part of a pressure generating chamber communicating with a nozzle opening, at least an upper surface of which functions as a lower electrode, a piezoelectric layer formed on the surface of the vibrating plate, and a piezoelectric layer A piezoelectric vibrator comprising an upper electrode formed on the surface and a piezoelectric active portion formed in a region facing the pressure generating chamber; and a piezoelectric active portion formed in a region facing the pressure generating chamber. An ink jet recording head provided with a contact portion serving as a connection portion between a conductive film for applying a voltage to the piezoelectric active portion and the conductive film, wherein the conductive film includes the contact portion in a planar manner, and An ink jet recording head extending to at least two peripheral walls of the pressure generating chamber. 2. The piezoelectric element according to claim 1, wherein an insulating layer is formed on an upper surface of the piezoelectric active portion, and the contact portion is formed in a contact hole formed in the insulating layer. Inkjet recording head. 3. The pressure sensor according to claim 1, wherein the conductive film is wider than a width of the pressure generating chamber and extends from a longitudinal end of the pressure generating chamber to a position above a contact portion. Inkjet recording head. 4. The pressure sensor according to claim 1, wherein the conductive film is wider than a dimension of the contact portion along a longitudinal direction of the pressure generating chamber, and is formed so as to straddle both side walls of the pressure generating chamber. An ink jet recording head characterized in that: 5. 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: