JPH11170505A - Ink-jet type recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink-jet type recording head which can limit a decrease in displacement amount of a piezoelectric active part and maintain durability. SOLUTION: In an ink-jet type recording head provided with a piezoelectric vibrator comprising a diaphragm constituting part of a pressure generation chamber 12 communicated with a nozzle opening and having at least an upper face act as a lower electrode 60, and a piezoelectric active part 320 including a piezoelectric layer 70 formed on a front face of the diaphragm and an upper electrode 80 formed on a front face of the piezoelectric layer 70, a contact part 90a as a connection part between a lead electrode 100 for impressing a voltage to the piezoelectric active part 320 and the piezoelectric active part 320 is set at a nearly central part of an area opposite to the pressure generation chamber 12, thereby restricting a resistance to the supply of a current, so that a decrease in displacement amount of the piezoelectric active part 320 is limited.

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, which uses a longitudinal vibration mode piezoelectric vibrator, in which a piezoelectric vibrator expands and contracts in the axial direction, and a flexural vibration mode piezoelectric vibrator. Has been put to practical use.

[0003] In the former case, the volume of the pressure generating chamber can be changed by bringing the end face of the piezoelectric vibrator into contact with an elastic plate, and 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 operation of attaching the piezoelectric vibrator to the elastic plate 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 elastic 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, if the area of the contact hole is formed relatively large with respect to the area of the upper electrode, durability can be obtained, but the displacement of the piezoelectric active portion cannot be increased. There is a problem. This is because the current density in the contact hole portion during driving can be relatively small, but the rigidity of the piezoelectric active portion increases. On the other hand, if the area of the contact hole is made relatively small with respect to the area of the upper electrode, the displacement of the piezoelectric active part can be increased, but the current density in the contact hole increases and the contact hole is broken. In addition, there is a problem that the piezoelectric layer suffers insulation breakdown due to migration due to overcurrent and lacks durability.

[0010] 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 forming technique is very thin, and therefore has lower rigidity and lower piezoelectric characteristics than those to which a piezoelectric vibrator is attached.

In view of such circumstances, an object of the present invention is to provide an ink jet recording head capable of suppressing a decrease in displacement of a piezoelectric active portion and maintaining durability.

[0012]

According to a first aspect of the present invention, there is provided a vibration plate which forms a part of a pressure generating chamber communicating with a nozzle opening and at least an upper surface of which functions as a lower electrode. In an ink jet recording head including a piezoelectric vibrator including a piezoelectric layer formed on the surface of the vibration plate and a piezoelectric active portion including an upper electrode formed on the surface of the piezoelectric layer, the pressure generating chamber is Ink-jet recording, wherein a contact portion serving as a connection portion between a lead electrode for applying a voltage to the piezoelectric body active portion and the piezoelectric body active portion is provided at a substantially central portion of the opposed region. In the head.

In the first aspect, the contact portion is located substantially at the center, and the resistance to current supply via the contact portion is small, so that the response speed is not greatly reduced and the number of contact portions is one. Therefore, the influence on the displacement amount is small.

According to a second aspect of the present invention, there is provided the ink jet recording head according to the first aspect, wherein an insulating layer is provided below the lead electrode.

In the second aspect, insulation between the lead electrode and the lower layer is performed via the insulator layer.

According to a third aspect of the present invention, in the first or second aspect, the lead electrode from the contact portion is:
An ink jet recording head is drawn to one side in the width direction of the piezoelectric active portion.

In the third aspect, the current is supplied via the lead electrode drawn to one side.

According to a fourth aspect of the present invention, in the first or second aspect, the width direction of the piezoelectric active portions is inclined from a direction orthogonal to the longitudinal direction, and the adjacent piezoelectric active portions are inclined. Wherein the lead electrode from the contact portion is drawn out to a position where the lead electrode does not interfere in the longitudinal direction of a region facing the partition wall therebetween.

In the fourth aspect, the lead electrodes can be drawn on both sides without interfering with the lead electrodes drawn from the adjacent piezoelectric active portions.

According to a fifth aspect of the present invention, in the fourth aspect, the lead electrode is drawn out on both sides in the width direction of the piezoelectric active portion and each extends in a direction opposite to the longitudinal direction. The feature is the ink jet recording head.

In the fifth aspect, the lead electrode can be drawn out on the same peripheral wall without interfering with the lead electrode drawn out from the adjacent piezoelectric active portion.

According to a sixth aspect of the present invention, in the fourth aspect, the lead electrode is drawn out to one side in the width direction of the piezoelectric active portion, and a partition wall between the adjacent piezoelectric active portions is formed. The lead electrodes are drawn out from the piezoelectric active portions on both sides in a region opposed to a part thereof and are respectively extended in the opposite direction of the longitudinal direction, and the lead electrodes are drawn out in a region opposed to other partition walls. The ink jet recording head is characterized in that it is not provided.

In the sixth aspect, a cap member or the like that covers the piezoelectric active portion can be bonded to the partition wall from which the lead electrode is not drawn out, and the durability of the piezoelectric active portion is improved. Further, the rigidity of the partition is improved.

According to a seventh aspect of the present invention, in the sixth aspect, the insulator layer is not formed on a region facing the partition from which the lead electrodes are not drawn out. In the ink jet recording head.

According to the seventh aspect, when a cap member or the like covering the piezoelectric active portion is bonded to the partition wall from which the lead electrode is not drawn out, the adhesion with the cap member or the like is improved.

According to an eighth aspect of the present invention, in the inkjet method according to the seventh aspect, the lower electrode film is removed on a region facing the partition from which the lead electrode is not drawn out. In the recording head.

In the eighth aspect, when a cap member or the like covering the piezoelectric active portion is bonded to the partition wall from which the lead electrode is not drawn out, the adhesion with the cap member or the like is further improved.

According to a ninth aspect of the present invention, in the seventh aspect, after the lead electrode is extended to the outside in the longitudinal direction of the piezoelectric active portion, the lead electrode is connected to the partition wall from which the lead electrode is not drawn out. An ink jet recording head is characterized in that the ink jet recording head has a wide portion that is widened in the direction of the facing region.

According to the ninth aspect, when mounting, it is possible to connect to the outside via the wide portion, and various mounting methods can be used.

According to a tenth aspect of the present invention, in any one of the first to ninth aspects, the pressure generating 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.

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

[0032]

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 a single crystal silicon 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 formed in advance by thermal oxidation.

On the other hand, a 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 a 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 to be 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.

Each of the pressure generating chambers 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 and has a thickness of, for example, 0.1 to 1 mm and a coefficient of linear expansion of 300 ° C. or less. , For example, 2.5-4.5 [× 10 ⁻⁶ / ° C.]. In addition, the ink supply communication port 21
May be a single slit or a plurality of slits crossing the vicinity of the ink supply side end of each pressure generating chamber 12. 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. The other surface of the sealing plate 20 forms 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 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 has one surface constituting 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.

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. 3A, first, a wafer of a silicon single crystal substrate 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. 3B, 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 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. 3C, 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. 3D, 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.
The piezoelectric film 70 and the upper electrode film 80 are patterned.

First, as shown in FIG. 4A, only the piezoelectric film 70 and the upper electrode film 80 are etched to pattern the piezoelectric active portion 320. Next, as shown in FIG. 4B, each pressure generation chamber 12 (in FIG.
(Before formation, but shown by a broken line) by removing the lower electrode film 60 at the portions corresponding to the arms of the vibration plate on both sides of the piezoelectric active portion 320, which are regions opposed to both sides in the width direction. The film removal part 350 is formed. By providing the lower electrode film removing unit 350 in this manner, the amount of displacement due to voltage application to the piezoelectric active unit 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.

Next, as shown in FIG. 4C, the lower electrode film 60 is etched to pattern the entire pattern of the lower electrode film 60.

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. 2).

Then, each piezoelectric active portion 3 of the insulator layer 90
A contact hole 90a is formed in a part of a portion corresponding to a substantially central portion 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. 5 shows a process of forming such an insulator layer and a lead electrode.

First, as shown in FIG. 5A, an insulator layer 90 is formed so as to cover the peripheral portion 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. 5B, 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 a substantially central portion of the contact hole 90a.

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

The above is the film forming process. After forming the film in this manner, as shown in FIG. 5C, the silicon single crystal substrate is anisotropically etched with the above-described alkali solution to form the pressure generating chamber 12 and the like.

FIG. 6 is a plan view and a sectional view of the ink jet recording head formed as described above.

As shown in FIG. 6A, the piezoelectric active portion 320 composed of the piezoelectric film 70 and the upper electrode film 80 is provided in a region facing the pressure generating chamber 12.
A lead electrode 100 is formed on the upper surface with an insulator layer 90 interposed therebetween. As shown in FIG. 6B, the upper electrode film 80 and the lead electrode 100 are connected by a contact hole 90 a formed in a region of the insulator layer 90 corresponding to a substantially central portion of the piezoelectric active portion 320. ing. Further, each pressure generating chamber 12 is formed along a direction orthogonal to the longitudinal direction, and each lead electrode 100 facing each piezoelectric active portion 320 has the same width from the contact hole 90a in this embodiment. It is pulled out to a region facing the direction peripheral wall, and extends to the connection terminal portion in the same direction on the peripheral wall.

As described above, the contact hole 90a is provided substantially at the center of the piezoelectric active portion 320, and by applying a voltage through the contact hole 90a, the resistance to current supply is reduced and the reduction in response speed is reduced. Further, since only one contact hole 90a is required, the influence on the decrease in the displacement amount is small, and the decrease in the ink weight and the ink ejection speed can be suppressed.

In such an ink jet recording head, a large number of chips are simultaneously formed on one wafer by the above-described series of film formation and anisotropic etching. It is divided into each flow path forming substrate 10 of one chip size. In addition, the divided flow path forming substrate 1
0 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 ink jet recording head thus constructed takes in ink from an ink inlet 42 connected to an external ink supply means (not shown) and fills the interior from the common ink chamber 31 to the nozzle opening 11 with ink. After that, a voltage is applied between the lower electrode film 60 and the upper electrode film 80 via the lead electrode 100 according to a recording signal from an external drive circuit (not shown), and the elastic film 50, the lower electrode film 60, and the piezoelectric body By flexing and deforming the film 70, the pressure in the pressure generating chamber 12 increases, and ink droplets are ejected from the nozzle openings 11.

(Embodiment 2) FIG. 7 shows a planar positional relationship and a cross section of a pressure generating chamber and a lead electrode of Embodiment 2.

As shown in FIG. 7A, in this embodiment, the widthwise direction of the piezoelectric active portions 320 is inclined from the direction orthogonal to the longitudinal direction, and the adjacent piezoelectric active portions 320 are inclined. Is the same as that of the first embodiment except that each of the lead electrodes 100 corresponding to the above is drawn out to one partition in the width direction in the opposite direction, and is extended on the partition in the opposite direction.

That is, the region between the pressure generating chambers 12 opposed to every other partition 13A is connected to the contact hole 90a of the adjacent piezoelectric active portion 320 through each lead electrode 1A.
00 is drawn out so as not to interfere. Therefore, the lead electrode 100 is not drawn out to the region facing the other every other partition 13B. Thereby, for example, the rigidity of the entire flow path forming substrate 10 is increased by fixing, for example, a cap member covering the piezoelectric active portion 320 to a region facing the partition 13B on which the lead electrode 100 is not formed by bonding or the like. Can be raised. Further, by using a cap member having a concave portion that seals the piezoelectric active portion 320, the piezoelectric active portion 320 is shielded from the outside air, and the film surface of the piezoelectric active portion 320 and the like is sealed in a dry atmosphere, thereby improving durability. Can be improved.

The lead electrodes 100 corresponding to the respective piezoelectric active portions 320 are drawn out to positions which do not interfere in the longitudinal direction of the region facing the partition wall therebetween, and extend on the partition wall to the connection terminal portion. It should be done.

The area facing the partition from which the lead electrode 100 has not been drawn out is not particularly limited. In the present embodiment, as shown in FIG. 7B, the insulator layer 90 is removed. A member bonding portion 390 is provided. Furthermore, as described above, since the lower electrode film 60 of the member bonding portion 390 has been removed, the lower electrode film 60 that is relatively easily peeled off.
A cap member or the like can be directly fixed to the elastic film 50 instead of the above, and the sealing performance can be improved.

It should be noted that the insulator layer removing section 390 does not have to be formed, and the pressure generating chamber 12 is provided in the present embodiment.
Although it is inclined from the direction perpendicular to the longitudinal direction, it goes without saying that it may be formed along the direction perpendicular to the longitudinal direction as in the first embodiment.

(Embodiment 3) FIG. 8 shows a planar positional relationship between a pressure generating chamber and a lead electrode according to Embodiment 3.

In this embodiment, as shown in FIG. 8, the lead electrode 100 is not formed after extending to a predetermined width on one partition in the width direction and extending to the outside of the pressure generating chamber 12. A lead electrode 1 adjacent to the region facing the partition
The second embodiment is the same as the second embodiment except that the wide portion 110 expanded to a size that does not interfere with 00 is formed.

In this way, connection can be made with the outside via the wide portion 110 at the time of mounting, and various mounting methods can be executed. Further, the mounting strength can be improved, and in particular, the higher the density, the more effective.

(Embodiment 4) FIG. 9 shows a planar positional relationship between the pressure generating chamber and the lead electrode according to Embodiment 4.

In the present embodiment, as shown in FIG. 9, the width direction of the piezoelectric active portion 320 is inclined from the direction orthogonal to the longitudinal direction, and each lead electrode 100A is connected to the piezoelectric active portion 320. This embodiment is the same as the first embodiment except that it is pulled out on the partition walls on both sides in the width direction so as not to interfere with each other and extends in the opposite direction to the longitudinal direction.

Therefore, since the lead electrode 100 is connected to the connection terminals in two directions, there is an effect that a current can easily flow through the piezoelectric active portion 320.

(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.

Further, although the example in which the flow path forming substrate is formed of a silicon single crystal substrate has been described, for example, it may be formed of ceramics.

FIG. 10 is an exploded perspective view of the embodiment configured as described above, and FIG. 11 is a cross-sectional view of the flow path.

As shown in the figure, in the present embodiment, a flow path forming substrate 210 in which the pressure generating chamber 12 is formed, and an elastic film 215 provided on one surface of the flow path forming substrate 210 to close the pressure generating chamber 12. A sealing plate 220 provided on the other surface of the flow path forming substrate 210, and a common ink chamber forming plate 230
The thin plate 241, the ink chamber side plate 240, and the nozzle substrate 250 are formed by integral molding of ceramics. Specifically, ceramic raw materials,
From the slurry prepared from the binder and the solvent, a green sheet as a material of each member is manufactured, and a precursor of each member is manufactured by processing each green sheet, and these are laminated and fired to be integrally molded. Manufacturing things.

The pressure generating chamber 12 is formed in the flow path forming substrate 210, and the ink supply communication port 221, the nozzle communication port 222, and the ink introduction port 22 are formed in the sealing plate 220.
3, a common ink chamber 231 communicating with each pressure generating chamber 12 via an ink supply communication port 221 and a nozzle communication port 222 are formed on the common ink chamber forming substrate 230, and the thin plate 241 is formed on the thin plate 241. A nozzle communication port 222 is formed, an opening 240 a and a nozzle communication port 222 are formed in the ink chamber side plate 240, and a nozzle opening communicating with each pressure generating chamber 12 through each nozzle communication port 222 is formed in the nozzle substrate 250. 211 are formed.

The ceramic material constituting each member is not particularly limited, and may be selected in view of formability, workability, and the like, and zirconium oxide, alumina, and the like are preferably used. In particular, as the elastic film 215, partially stabilized or fully stabilized zirconia is preferably used.

The lower electrode film 60, the piezoelectric film 70 and the upper electrode film 80 formed on the elastic film 215,
The insulator film 90 and the lead electrode 100 can be formed by a film formation and a lithography process as in the above-described embodiment.

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 the embodiment described above, a pressure generating chamber is formed by laminating a thin-film type ink jet recording head and a substrate which can be manufactured by applying a film forming and lithography process, and a green sheet is attached by bonding or the like. Although an example in which a piezoelectric film is formed has been described as an example, the present invention is not limited to this. For example, the present invention is applied to an ink jet recording head having various structures such as a method in which a piezoelectric film is formed by crystal growth. can do.

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.

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.

[0092]

As described above, according to the present invention, the contact hole is provided substantially at the center of the piezoelectric active portion, and the lead electrode extends on the partition wall in the width direction. A sufficient voltage can be applied to the portion, and a decrease in the ink discharge amount and the ink discharge speed can be suppressed.

[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 thin film manufacturing process according to the first embodiment of the present invention.

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 plan view and a cross-sectional view illustrating a main part of the inkjet recording head according to the first embodiment of the present invention.

FIGS. 7A and 7B are a plan view and a cross-sectional view illustrating a main part of an inkjet recording head according to a second embodiment of the invention.

FIG. 8 is a plan view showing a main part of an ink jet recording head according to Embodiment 3 of the present invention.

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

FIG. 10 is an exploded perspective view of an ink jet recording head according to another embodiment of the present invention.

FIG. 11 is a cross-sectional view showing 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 13A, 13B partition 50 elastic film 60 lower electrode film 70 piezoelectric film 80 upper electrode film 90 insulator layer 100 lead electrode 320 piezoelectric active portion 350 lower electrode removing portion 390 member Bonded part

Claims (10)

[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 serving as a lower electrode, a piezoelectric layer formed on the surface of the vibrating plate, and a piezoelectric layer formed on the surface of the vibrating plate. In an ink jet recording head including a piezoelectric vibrator including a piezoelectric active portion formed of an upper electrode formed on the surface, a voltage is applied to the piezoelectric active portion at a substantially central portion of a region facing the pressure generation chamber. An ink jet type recording head provided with a contact portion serving as a connecting portion between a lead electrode and a piezoelectric active portion. 2. The ink jet recording head according to claim 1, wherein an insulating layer is provided below the lead electrode. 3. The ink jet recording head according to claim 1, wherein the lead electrode from the contact portion is drawn to one side in the width direction of the piezoelectric active portion. 4. The lead from the contact portion of an adjacent piezoelectric active part according to claim 1 or 2, wherein the direction in which the piezoelectric active parts are arranged in the width direction is inclined from a direction orthogonal to the longitudinal direction. An ink jet recording head, wherein the electrode is drawn out to a position not interfering with a longitudinal direction of a region facing the partition wall between them. 5. The method according to claim 4, wherein the lead electrode comprises:
An ink jet recording head, which is drawn out on both sides in the width direction of the piezoelectric active portion and extends in a direction opposite to the longitudinal direction, respectively. 6. The method according to claim 4, wherein the lead electrode comprises:
The lead electrodes are drawn out to one side in the width direction of the piezoelectric body active portion, and the lead electrodes from the piezoelectric body active portions on both sides are drawn out in a region facing a part of the partition wall between the adjacent piezoelectric body active portions. An ink jet recording head, wherein the lead electrode is not extended to a region facing each other and extending in a direction opposite to the longitudinal direction. 7. The ink jet recording head according to claim 6, wherein the insulator layer is not formed on a region facing the partition from which the lead electrodes are not drawn out. 8. The ink jet recording head according to claim 7, wherein the lower electrode film is removed on a region facing the partition from which the lead electrode is not drawn out. 9. The lead electrode according to claim 7, wherein:
An ink jet recording head, comprising: a wide portion extending to the outside in the longitudinal direction of the piezoelectric active portion, and then expanded in a region facing the partition from which the lead electrode is not drawn out. 10. 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: