JPH11115186A - Ink-jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink-jet recording head which alleviates the initial defect of a channel forming substrate and can prevent the deterioration of piezoelectric properties and the dispersion of the piezoelectric properties in a chip. SOLUTION: In an ink-jet recording head equipped with a channel forming substrate 10 which is equipped with, on one side, a line of pressure generation chambers 12 which communicate with a nozzle opening and are divided by partition walls and, on the other side, a piezoelectric vibrator consisting of a piezoelectric material active part formed in an area opposed to the chamber 12 and a vibration plate constituting a part of the chamber 12 and a joining member 110 to be joined with the other side of the substrate 10. The substrate 10 is joined with the member 110 with one side bent in the direction to be a projected surface in the direction of the line of the chambers 12, the initial stress of the substrate 10 is alleviated.

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 communicating with a nozzle opening for discharging ink droplets, wherein the pressure generating chamber is partially constituted by a vibrating plate, and a piezoelectric layer on the surface of the vibrating plate is formed. 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.

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.

Further, in this case, for example, a silicon single crystal substrate is used as a substrate, and flow paths such as a pressure generation chamber and a reservoir are formed by anisotropic etching to reduce the opening area of the pressure generation chamber as much as possible. Thus, the recording density can be improved.

[0008]

However, when a piezoelectric active portion facing each pressure generating chamber is formed on such a silicon single crystal substrate by forming a thin film and patterning, a stress during film formation remains. To the initial stress,
There is a problem that the characteristics of the piezoelectric vibrator are deteriorated. Also,
A member such as a communication plate or a sealing plate to be joined to such a flow path forming substrate is usually made of stainless steel or glass, and thus has a different coefficient of linear expansion. Therefore, since heat is applied at the time of bonding, warpage occurs after bonding, which increases the stress remaining on the piezoelectric vibrator, further reducing the piezoelectric characteristics and increasing the variation in characteristics within the chip. There is a fear.

In order to increase the recording density, it is necessary to reduce the wall thickness of the partition wall for partitioning the pressure generating chamber, thereby reducing the rigidity of the partition wall for partitioning the pressure generating chamber. Encourage.

In view of such circumstances, the present invention provides an ink jet recording head capable of alleviating initial failure of a flow path forming substrate and preventing a decrease in piezoelectric characteristics and a variation in piezoelectric characteristics in a chip. That is the task.

[0011]

According to a first aspect of the present invention, there is provided:
On one surface, a row of pressure generating chambers which are communicated with the nozzle openings and are partitioned by a plurality of partitions are provided, and on the other surface, a diaphragm constituting a part of the pressure generating chamber and a region opposed to the pressure generating chamber are formed. A flow path forming substrate provided with a piezoelectric vibrator made of a separated piezoelectric active portion; and a joining member joined to the other surface of the flow path forming substrate. Is joined to the joining member in a state where the one surface is bent in a direction in which the one surface becomes a convex surface along the row direction of the pressure generating chambers.

In the first aspect, the initial stress of the flow path forming substrate is reduced by bonding the flow path forming substrate to the bonding member in a bent state.

According to a second aspect of the present invention, in the first aspect, a joining surface of the joining member with the flow path forming substrate is a convex surface along a row direction of the pressure generating chambers. An ink jet recording head is characterized in that a concave portion is formed in a region opposed to the portion so as to allow the driving of the piezoelectric active portion.

[0014] In the second aspect, the flow path forming substrate is joined along the convex surface, so that the substrate is held in a bent state and the initial stress is relaxed, while the piezoelectric active portion is accommodated in the concave portion. Is done.

A third aspect of the present invention is the ink jet recording head according to the second aspect, wherein the recess is formed in a shape corresponding to each of the piezoelectric active portions.

In the third aspect, each of the piezoelectric active portions is located in the corresponding concave portion, and its driving is allowed.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the flow path forming substrate is attached to the joining member in a state where the stress of the piezoelectric active portion before the joining is reduced. An ink jet type recording head is characterized by being joined.

In the fourth aspect, the initial stress of the flow path forming substrate is reduced, and the piezoelectric characteristics are improved.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the flow path forming substrate is joined to the joining member in a state in which warpage before joining is further increased. The feature is the ink jet recording head.

In the fifth aspect, the initial stress is reduced by further increasing the bending of the flow path forming substrate.

According to a sixth aspect of the present invention, in any one of the first to fifth 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 sixth 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 embodiments.

(Embodiment 1) FIG. 1 is an assembled perspective view showing an ink jet recording head according to Embodiment 1 of the present invention, and 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, 2.5-4.5 [× 10 ⁻⁶ / ° C.]. In addition, the ink supply communication port 21
Each of the pressure generating chambers 1 is, as shown in FIGS.
It may be one slit hole 21A crossing the vicinity of the second ink supply side end or a plurality of slit holes 21B. The sealing plate 20 entirely covers one surface of the flow path forming substrate 10 on one surface, and also serves as a reinforcing plate for protecting the silicon single crystal substrate from impact and external force. In addition, the sealing plate 20
The other surface constitutes one wall surface of the common ink chamber 31.

The common ink chamber forming substrate 30 forms the peripheral wall of the common ink chamber 31, and is formed by punching a stainless steel plate having an appropriate thickness 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
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.

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
A contact hole 90a that exposes a part of the upper electrode film 80 for connecting to a lead electrode 100 described later is formed in a part of the part that covers the upper surface of the part corresponding to one end of 20. One end is connected to each upper electrode film 80 via the contact hole 90a, and the other end is formed with a lead electrode 100 extending to the connection terminal portion.

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

First, as shown in FIG. 6A, an insulator layer 90 is formed so as to cover the periphery of the upper electrode film 80 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 lead electrode 100 and an upper electrode film 80 described later. The contact hole 90
a may be provided at a portion of the pressure generating chamber 12 corresponding to the piezoelectric active portion 320, and may be provided at, for example, a central portion or a nozzle-side end portion.

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

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, as shown in FIG. It is divided into each flow path forming substrate 10 having a single chip size.

The flow path forming substrate 10 has an initial stress remaining due to shrinkage of the formed film and the like, and warps, though slightly, the surface on which the pressure generating chamber 12 is formed on the convex side.
In the present embodiment, the film forming surface of the flow path forming substrate 10 is joined to the holding member 110.

The holding member 110 of the present embodiment also serves as a case for finally holding the entire ink jet recording head, and the bonding surface with the flow path forming substrate 10 has a convex surface 111.
And a concave portion 112 for allowing the piezoelectric active portion formed by the above-described film formation to escape.

Here, the convex surface 111 is bent so that the above-described warpage of the flow path forming substrate 10 is further promoted by tightly joining the flow path forming substrate 10 to the convex surface 111.

The holding member 110 needs to have such a rigidity that the holding member 110 is not deformed even if it receives the reaction force of the flow path forming substrate 10 which is tightly joined. However,
It may have a convex surface having a larger bend than a required bend, and may be deformed by the reaction force of the flow path forming substrate 10 after joining, resulting in an appropriate bend.

The recess 112 may be a groove having a predetermined depth or a through-hole as long as it can allow the driving of the piezoelectric active portion. The through holes are used because of wiring and the like.

As described above, the flow path forming substrate 10 is connected to the joining member 1.
When joined to the convex surface 111 of 10, the film-forming portion of the flow path forming substrate 10 is further subjected to stress in the compression direction, and the initial stress can be eliminated or reduced.

Here, the degree of bending of the convex surface 111 is not particularly limited as long as the initial stress can be relieved as described above. For example, when the dimension of the pressure generating chamber 12 in the row direction is about 10 mm, the maximum The protrusion amount of the protrusion is several μm
To about several tens μm.

The material of the joining member 110 is not particularly limited. For example, the resin may be integrally molded by injection molding or the like, or may be made of metal and the convex surface is formed by laser processing or polishing.

The joining means is not particularly limited, and the joining can be conveniently performed using an adhesive.

The flow path forming substrate 10 thus bonded to the bonding member 110 is further bonded and integrated with the sealing plate 20, the common ink chamber forming substrate 30, and the ink chamber side plate 40 in this order to form an ink jet recording head. And The order of joining the flow path forming substrate 10 and each member is not particularly limited. For example, the joining with the joining member 110 may be performed last.

The ink jet recording head has an ink inlet 4 connected to an external ink supply means (not shown).
2 is filled with ink from the common ink chamber 31 to the nozzle opening 11, and the lower electrode film 60 and the upper electrode 60 are connected via the lead electrode 100 in accordance with a recording signal from an external driving circuit (not shown). A voltage is applied between the elastic film 50, the lower electrode film 60, and the piezoelectric film 7.
By deforming 0, the pressure in the pressure generating chamber 12 increases, and ink droplets are ejected from the nozzle opening 11.

(Embodiment 2) FIG. 7 is an exploded perspective view of an ink jet recording head according to Embodiment 2, and FIG.

The bonding member 110A of this embodiment is basically the same as the bonding member 110 described above, and has a convex surface 111A.
However, the concave portion 112A has a shape corresponding to each piezoelectric active portion. That is, in the concave portion 112A, substantially half of the end side is the penetrating portion 112a, but the other half is the groove portion 112b for each piezoelectric active portion. Therefore, the support portion 113 is provided between the groove portions 112b, and the support portion 113 comes into contact with a non-active portion between the piezoelectric active portions.

By adopting such a shape, the effect of alleviating the initial stress is the same, but the flow path forming substrate 10 is securely held by the joining member 110A, and the variation of the piezoelectric characteristics is suppressed. You.

In the above-described embodiment, the nozzle openings are formed on the end surface of the flow path forming substrate 10, but in the present embodiment, the nozzle openings are formed to project in a direction perpendicular to the surface. That is, in the present embodiment, the nozzle openings 11 are formed in the nozzle substrate 120 opposite to the piezoelectric vibrator, and the nozzle communication ports 22 that communicate the nozzle openings 11 and the pressure generating chambers 12 are formed by the sealing plates 20 and Common ink chamber forming plate 30
And, it is arranged so as to penetrate 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 40A. Is omitted.

The joining member 110A may be, for example, an integrally molded resin or a metal block processed, or may be formed by combining a plurality of members. That is, as shown in FIG. 9, the first joining member 210a having a through hole 212 corresponding to the through portion 112a.
And the through-hole 222a and the groove 11 communicating with the through-hole 212
2b for forming a groove corresponding to 2b
and a second joining member 210b having the same shape as the joining member 110A described above.

Here, in this embodiment, the first joining member 210a has a convex surface 211a having a predetermined bend,
On the other hand, the second joining member 210b has a flat plate shape,
The second bonding member 210b has a convex surface 211b having a predetermined curvature by being bonded to the convex surface 211b of the first bonding member 210a.

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

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

Further, 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 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. However, the present invention is not limited to this. Ink jet recording heads of various structures, such as one that forms a pressure generating chamber by laminating, one that forms a piezoelectric film by pasting a green sheet or screen printing, or one that forms a piezoelectric film by crystal growth The present invention can be adopted for the present invention.

Further, in each of the above-described embodiments, an elastic film is provided as a diaphragm in addition to the lower electrode film, 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 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.

[0079]

As described above, in the present invention,
By joining the flow path forming substrate to the joining member in a bent state, the initial stress is alleviated, and the effect of preventing the deterioration or variation in the piezoelectric characteristics is prevented.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of the ink jet recording head according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a modification of 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 view showing a thin film manufacturing process according to the first embodiment of the present invention.

FIG. 7 is an exploded perspective view of an ink jet recording head according to Embodiment 2 of the present invention.

FIG. 8 is a sectional view of an ink jet recording head according to a second embodiment of the present invention.

FIG. 9 is an exploded perspective view of an ink jet recording head according to another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 flow path forming substrate 12 pressure generating chamber 14 reservoir 15 ink supply port 16 ink introduction port 17 nozzle opening 18 nozzle plate 21, 21A, 21B slit 50 elastic film 60 lower electrode film 70 piezoelectric film 80 upper electrode film 90 insulator layer 90a Contact hole 100 Lead electrode 110, 110A Joint member 111, 111A Convex surface 112, 112A Concave portion

Claims (6)

[Claims] A pressure generating chamber is provided on one side with a row of pressure generating chambers communicating with a nozzle opening and divided by a plurality of partitions, and on the other side, a diaphragm and a part of the pressure generating chamber are provided. A flow path forming substrate including a piezoelectric vibrator formed of a piezoelectric active portion formed in an opposed region, and an ink jet recording head including a bonding member bonded to the other surface of the flow path forming substrate, The ink jet recording head according to claim 1, wherein the flow path forming substrate is joined to the joining member in a state where the one surface is bent in a direction in which the one surface becomes a convex surface along the row direction of the pressure generating chambers. 2. The pressure generating chamber according to claim 1, wherein a bonding surface of the bonding member with the flow path forming substrate is a convex surface along a row direction of the pressure generating chamber, and a region facing the piezoelectric active portion is provided. An ink jet recording head, wherein a concave portion allowing driving of the piezoelectric body active portion is formed. 3. The ink jet recording head according to claim 2, wherein the recess is formed in a shape corresponding to each of the piezoelectric active portions. 4. The flow channel forming substrate according to claim 1, wherein the flow path forming substrate is bonded to the bonding member in a state where stress of the piezoelectric active portion before bonding is reduced. Inkjet recording head. 5. The ink jet recording head according to claim 1, wherein the flow path forming substrate is bonded to the bonding member in a state where warpage before bonding is further increased. 6. The pressure generating chamber according to claim 1, wherein the pressure generating chamber is formed on a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric vibrator is formed by film formation and lithography. An ink jet recording head, characterized in that: