JPH11157062A - Ink jet type recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent cracks or the like to be generated in the vicinity of a peripheral wall of a pressure generating chamber of a piezoelectric body active section and secure durability. SOLUTION: An ink jet type recording head is provided with a piezoelectric vibrator with a piezoelectric body active section 320 constituted of a piezoelectric body layer 70 and an upper electrode 80 on a vibration plate surface constituting a part of a pressure generating chamber 12 communicated with a nozzle hole, and the piezoelectric body active section 320 is provided with a connecting section 321 across the boundary between an area facing the pressure generating chamber 12 and an area facing the peripheral wall of a longitudinal direction end of the pressure generating chamber 12 formed at least on one end section, and vibration control layer coating at least the piezoelectric body active section 320 and controlling the vibration of the vibration plate is formed on the side, on which at least the connecting section 321 formed, of the longitudinal direction end of the pressure generating chamber 12. The vibration of the vibration plate in an area facing the vicinity of the boundary of the pressure generating chamber 12 is controlled by the arrangement to prevent the breakdown generated by cracks and improve durability.

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 driving voltage and the stress applied to the piezoelectric layer at the part facing the pressure generating chamber and the part straddling the outside, the piezoelectric active part consisting of the piezoelectric layer and the upper electrode is However, it is desirable that at least one end be formed so as not to go outside the pressure generating chamber.

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

[0009]

However, in the above-described recording head using the flexural mode piezoelectric vibrator, the piezoelectric active portion crosses the boundary between the pressure generating chamber and its peripheral wall, and cracks in the piezoelectric layer. There is a problem that is easily generated.

Incidentally, in the above-mentioned ink jet recording head as described above, in order to improve the displacement efficiency of the diaphragm by driving the piezoelectric vibrator, a structure in which portions of the diaphragm corresponding to both sides of the piezoelectric vibrator are thinned. Proposed.
However, such a large displacement promotes the tendency of breakage such as cracks to occur particularly near the peripheral wall of the pressure generating chamber or near the contact hole as described above.

[0011] These problems tend to occur particularly when the piezoelectric material layer is formed by a film forming technique. This is because the piezoelectric material layer formed by the film formation technique is extremely thin, and therefore has lower rigidity than a piezoelectric vibrator attached thereto.

In view of such circumstances, the present invention can prevent the peeling and cracking near the peripheral wall of the pressure generating chamber of the piezoelectric active portion, the cracking of the diaphragm, etc., and can ensure the durability of the ink jet type. It is an object to provide a recording head.

[0013]

According to a first aspect of the present invention, there is provided a diaphragm which forms a part of a pressure generating chamber which communicates with a nozzle opening and has at least an upper surface serving as a lower electrode. A piezoelectric vibrator comprising: a piezoelectric layer formed on the surface of the vibration plate; and 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. An ink jet recording head having a connecting portion at at least one end of the piezoelectric active portion, which crosses a boundary between a region facing the pressure generating chamber and a region facing a peripheral wall at a longitudinal end of the pressure generating chamber. , A vibration regulating layer that is laminated on at least the piezoelectric active portion near the end of the longitudinal end of the pressure generating chamber at the side where the connecting portion is provided and regulates the vibration of the diaphragm. To In an ink jet recording head, characterized by.

In the first aspect, the vibration of the vibration plate at the end portion or the connection portion of the piezoelectric active portion is regulated, and peeling and cracking of the piezoelectric active portion and cracking of the diaphragm are prevented.

According to a second aspect of the present invention, in the first aspect, the insulating layer formed so as to cover at least the vicinity of the longitudinal end of the pressure generating chamber constitutes the vibration regulating layer. The feature is the ink jet recording head.

In the second aspect, the insulating layer provides
Peeling and cracking of the piezoelectric active portion near the longitudinal end of the pressure generating chamber and cracking of the diaphragm are prevented.

According to a third aspect of the present invention, in the first or second aspect, a layer provided on at least the connecting portion of the piezoelectric active portion constitutes the vibration regulating layer. In the ink jet recording head.

In the third aspect, peeling and cracking of the piezoelectric active portion at a portion corresponding to the connecting portion and cracking of the diaphragm are prevented.

According to a fourth aspect of the present invention, there is provided an ink jet recording head according to the third aspect, wherein the vibration regulating layer is formed by making the upper electrode thicker than other portions. is there.

In the fourth aspect, the vibration is regulated by making the thickness of the upper electrode larger than that of the other portions, and peeling and cracking of the piezoelectric active portion and cracking of the diaphragm are prevented.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, at least portions of the vibrating plate along the edge of the pressure generating chamber on both sides in the width direction of the piezoelectric active portion are provided. And a thin portion thinner than a thickness of the diaphragm at a portion corresponding to the piezoelectric active portion.

In the fifth aspect, the amount of displacement caused by applying a voltage to the piezoelectric active portion in the region facing the pressure generating chamber is improved.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the connecting portion is formed such that both the piezoelectric layer and the upper electrode are formed narrower than other portions. An ink jet recording head is characterized in that:

[0024] In the sixth aspect, the stress at the connecting portion is reduced, and breakage such as cracks is prevented.

According to a seventh aspect of the present invention, in any one of the first to fifth aspects, the connection portion is formed such that only the upper electrode is formed narrower than other portions. Ink-jet recording head.

In the seventh aspect, the stress at the connecting portion is reduced, breakage such as cracks is prevented, and durability is improved.

According to an eighth aspect of the present invention, in any one of the first to seventh aspects, a contact portion for connecting a lead electrode for applying a voltage to the piezoelectric active portion to the upper electrode is provided. An ink jet recording head is provided at a portion facing a peripheral wall of the pressure generating chamber.

In the eighth aspect, breakage of a crack or the like at the contact portion is prevented.

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

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

[0031]

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

(Embodiment 1) FIG. 1 is an assembled perspective view showing an ink jet recording head according to Embodiment 1 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 made 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 a 0.1 to 2 μm thick elastic film 50 made of silicon dioxide previously formed by thermal oxidation.

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, the substrate is gradually eroded and the first (111) plane perpendicular to the (110) plane and the first (111) plane are formed. 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, has a thickness of, for example, 0.1 to 1 mm, and has 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 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, the thickness of the elastic film 50 on the opposite side of the opening surface of the flow path forming substrate 10 is, 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 region facing each pressure generating chamber 12, a piezoelectric vibrator is provided independently for each pressure generating chamber 12, and 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 film 70 is connected to each pressure generating chamber 12.
However, the piezoelectric film may be provided as a whole, and the upper electrode film 80 may be separately provided so as to correspond to each pressure generating chamber 12. In any case, each pressure generating chamber 1
That is, a piezoelectric active portion is formed every two.

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
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 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. 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. The lower electrode film removing unit 350 does not completely remove the lower electrode film 60,
The thickness may be made relatively thin, or a part of the elastic film 50 in the thickness direction may be removed.

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. 1). At this time, as will be described later, both ends of the piezoelectric active portion 320 are provided with the insulating layer 90 of another portion.
Is formed thicker than the thickness of the insulator layer 95.

In this embodiment, a part of the insulating layer thick film portion 95 that covers the upper surface of the portion corresponding to one end of each piezoelectric active portion 320 has a lead electrode 100 described later.
A contact hole 90a exposing a part of the upper electrode film 80 is formed to connect with the contact hole 90a. One end is connected to each upper electrode film 80 via the contact hole 90a, and the other end is connected to the lead electrode 10 extending to the connection terminal portion.
0 is formed. The lead electrode 100 is formed so as to be as narrow as possible so as to reliably supply a drive signal to the upper electrode film 80.

FIG. 6 shows a process for forming such an insulator layer.
Shown in

First, as shown in FIG. 6A, an insulator layer 90 is formed so as to cover the peripheral portion of the upper electrode film 80 and the side surfaces of the piezoelectric film 70 and the lower electrode film 60. An insulator layer is laminated on both ends of the active portion 320, and an insulator layer thick film portion 95 thicker than other portions is formed. In this embodiment, a negative photosensitive polyimide is used for the insulator layer 90 and the insulator layer thick part 95.

Next, as shown in FIG. 6B, a contact hole 90a is formed in a portion of each of the pressure generating chambers 12 facing the ink supply side peripheral wall by patterning the insulator layer thick film portion 95. I do. Subsequently, for example, Cr-A
After a conductor such as u is formed on the entire surface, patterning is performed to form the lead electrode 100 connected to the upper electrode film 80 via the contact hole 90a. In addition,
FIG. 6B shows a cross section of the contact hole 90a in a region facing the peripheral wall outside the pressure generating chamber 12 for convenience of explanation.

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 the process is completed, the flow path forming substrate 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.

The thus formed piezoelectric active portion 320
FIG. 7 shows a planar positional relationship and a cross section between the insulator layer thick film portion 95 and the pressure generating chamber 12.

As shown in FIG. 7A, the piezoelectric active portion 320 including the piezoelectric film 70 and the upper electrode film 80 is basically provided in a region facing the pressure generating chamber 12,
The width of the pressure generation chamber 12 is slightly smaller than the width of the pressure generation chamber 12.
In addition, at one end of the pressure generation chamber 12, the area continuously extends from the area facing the pressure generation chamber 12 to the area facing the peripheral wall, and the area facing the pressure generation chamber 12 and the area facing the peripheral wall. The vicinity of the boundary with is referred to as a connecting portion 321.

On the piezoelectric active portion 320 in a region facing the pressure generating chamber 12, an insulator layer 90 having a normal thickness is formed as shown in a BB 'section of FIG. 7B. However, on both ends of the piezoelectric active part 320 and on the connecting part 321, as shown in the cross section CC ′ of FIG. 95 are formed to form a vibration regulation layer 325 for regulating the vibration of the diaphragm. A contact hole 90 a for connecting the lead electrode 100 and the upper electrode film 80 is formed at a position corresponding to the piezoelectric active portion 320 in a region facing the peripheral wall.

Further, the lower electrode film 60 facing the vicinity of the boundary with the peripheral walls on both sides in the width direction of the pressure generating chamber 12 and on both sides of the piezoelectric active portion 320, ie, the arm portion of the diaphragm is removed. An electrode film removing part 350 is formed.

With this configuration, when the piezoelectric active portion 320 is driven by applying a voltage, the drive of both ends and the connecting portion 321 is restricted, and the displacement amount is reduced only in the vicinity of this portion. It is relatively small, and the amount of displacement at the end can be suppressed without greatly reducing the amount of displacement as a whole, and peeling and cracking of the end of the piezoelectric active portion 320 and cracking of the diaphragm are prevented. can do.

In this embodiment, the insulator layer thick film portion 95 is provided on both ends of the piezoelectric active portion 320 and on the connecting portion 321, but may be provided only on the connecting portion 321 side. Also, the insulator layer thick film portion 95 may be thicker relatively than other portions. Therefore, another layer may be stacked on the insulator layer 90, or an insulator layer having a normal thickness may be provided only on the insulator layer thick portion 95.

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.

(Embodiment 2) FIG. 8 shows a planar positional relationship and a cross section of a piezoelectric active portion and the like near a pressure generating chamber of an ink jet recording head according to Embodiment 2 of the present invention.

In this embodiment, a thick film portion 85 thicker than the upper electrode film 80 of the other portion is formed on the piezoelectric film 70 in a region opposed to the boundary and the peripheral wall of the pressure generating chamber 12 to form the vibration regulating layer 325A. In a region opposed to the region of the pressure generating chamber 12, the vibration of the diaphragm is regulated.

As shown in FIG. 8A, the piezoelectric active portion 3
20 is basically the same as the first embodiment.
At one end of the pressure generating chamber 12, and is continuously extended from the area facing the pressure generating chamber 12 to the area facing the peripheral wall via a connecting portion 321 that crosses over the peripheral wall. ing. An insulator layer 90 is formed on the piezoelectric active portion 320, and a lead electrode 100 is provided at a position corresponding to the piezoelectric active portion 320 in a region facing the peripheral wall.
Hole 9 for connecting the electrode with upper electrode film 80
0a is formed. In addition, the lower electrode film 60 at the arm portion of the diaphragm is removed to form a lower electrode film removing portion 350.

The upper electrode film 80 has a normal thickness in a region facing the pressure generating chamber 12 as shown in a section DD ′ of FIG. 321 and the region facing the peripheral wall, as shown in the EE ′ cross section of FIG. 8C, becomes a thick film portion 85 thicker than other portions.
It constitutes the vibration regulation layer 325A.

With this configuration, the same effects as in the first embodiment can be obtained.

In the present embodiment, the thick film portion 85 is formed on the piezoelectric film 70 in a region opposed to the connecting portion 321 and the peripheral wall, but at least on the piezoelectric film 70 of the connecting portion 321. If so, a similar effect can be obtained.

Further, the structure of the present embodiment may be further provided with an insulator layer thick film portion 95 as in the first embodiment, whereby a more remarkable effect is exerted.

(Embodiment 3) FIG. 9 shows a pattern shape of a piezoelectric active portion and the like near a pressure generating chamber of an ink jet recording head according to Embodiment 3 of the present invention.

In the present embodiment, as shown in FIG. 9, the connecting portion 322, which is a portion crossing from the region facing the pressure generating chamber 12 of the piezoelectric active portion 320 to the region facing the peripheral wall, is narrower than other portions. It is the same as the first embodiment except for the following. Note that the connecting portion 322 of the present embodiment is
And both the upper electrode film 80 and the upper electrode film 80 are formed narrow.

In such a configuration, the piezoelectric active section 320
Is driven, the connecting portion 32 is formed by the insulator layer thick film portion 95.
In addition to the fact that the vibration of the diaphragm is suppressed in the region facing the peripheral wall 2 and the peripheral wall, furthermore, the bending is gradually generated in the pressure generating chamber 12 and from the boundary of the peripheral wall toward the pressure generating chamber 12. Stress is reduced, breakage such as cracks is prevented, and durability is improved.

(Embodiment 4) FIG. 10 shows a pattern shape of a piezoelectric active portion and the like near a pressure generating chamber of an ink jet recording head according to Embodiment 4 of the present invention.

In this embodiment, as shown in FIG. 10, the connecting portion 323 of the piezoelectric active portion 320 is formed so that only the upper electrode film 80 is narrow, and the piezoelectric layer 70 has the same thickness as the other portions. The third embodiment is the same as the third embodiment except for the following.

With such a configuration, the same effect as in the third embodiment can be obtained.

(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.

In this embodiment, as in the above-described embodiments, a vibration regulating layer is provided to regulate the vibration of the piezoelectric active portion, and to prevent cracks near the boundary with the periphery of the pressure generating chamber. Can be prevented.

Further, needless to say, the present invention can be similarly applied to an ink jet recording head of a type in which a common ink chamber is formed in 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. However, 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 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 gist of the present invention is not contradicted.

[0089]

As described above, according to the present invention, the vibration regulating layer for relatively regulating the vibration of the diaphragm accompanying the driving of the piezoelectric active portion is provided near the boundary of the pressure generating chamber. The flexure of this portion is smaller than that of the other portions, so that cracks and the like are prevented from being broken and the durability is 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.

7A and 7B are a plan view and a cross-sectional view illustrating a main part of the first embodiment of the present invention.

8A and 8B are a plan view and a cross-sectional view of a main part illustrating a second embodiment of the present invention.

FIG. 9 is a main part plan view for explaining Embodiment 3 of the present invention.

FIG. 10 is a main part plan view for explaining Embodiment 4 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 insulating layer 90a contact hole 100 lead electrode 320 piezoelectric active portion 321, 322, 323 connecting portion 325 , 325A Vibration control layer 350 Lower electrode film removal part

Claims (9)

[Claims] 1. A vibrating plate constituting a part of a pressure generating chamber communicating with a nozzle opening and having at least an upper surface acting 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 a surface thereof and a piezoelectric active portion formed in a region opposed to the pressure generating chamber, wherein at least one end of the piezoelectric active portion is provided in the pressure generating chamber. In an ink jet recording head having a connecting portion that crosses a boundary between a facing region and a region facing a peripheral wall at a longitudinal end of the pressure generating chamber, at least the connecting portion at a longitudinal end of the pressure generating chamber is provided. An ink jet recording head, comprising a vibration regulation layer laminated on at least the piezoelectric active portion near the end and regulating the vibration of the diaphragm on the side of the recording medium. 2. The ink jet recording head according to claim 1, wherein an insulator layer laminated so as to cover at least a vicinity of an end in the longitudinal direction of the pressure generating chamber constitutes the vibration regulating layer. 3. The ink jet recording head according to claim 1, wherein a layer provided on at least the connecting portion of the piezoelectric active portion constitutes the vibration regulating layer. 4. The ink jet recording head according to claim 3, wherein the vibration regulating layer is formed by making the upper electrode thicker than other portions. 5. The piezoelectric element according to claim 1, wherein at least a portion of the diaphragm along the edge of the pressure generating chamber on both sides in the width direction of the piezoelectric element corresponds to the piezoelectric element. An ink jet recording head, wherein the thin portion is thinner than the thickness of the vibrating plate. 6. The ink jet printer according to claim 1, wherein the connecting portion is formed such that both the piezoelectric layer and the upper electrode are formed narrower than other portions. Type recording head. 7. The ink jet recording head according to claim 1, wherein the connection portion is formed such that only the upper electrode is formed narrower than other portions. 8. The pressure generating chamber according to claim 1, wherein a contact portion for connecting a lead electrode for applying a voltage to the piezoelectric active portion and the upper electrode faces a peripheral wall of the pressure generating chamber. An ink jet recording head provided in a portion to be formed. 9. 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: