JP2000263778A - Actuator apparatus, ink jet recording head and ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an apparatus small by saving a space for a mount part. SOLUTION: An area of a piezoelectric element 300 of a substrate 10 at the side of one end in a longitudinal direction is a mount part 130 where a connecting part 120 for electrically connecting an electrode wiring 110 extending from the piezoelectric element 300 and an external wiring 40 is set and the external wiring 40 is secured on the substrate 10. A recessed part 140 is formed by removing part of the substrate 10 on the substrate 10 corresponding to the mount part 130. The recessed part 140 is an escape for an adhesive for securing the external wiring 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator device in which a part of a cavity is formed by a diaphragm, a piezoelectric element is provided through the diaphragm, and the diaphragm is deformed by displacement of the piezoelectric element. The present invention relates to an ink jet recording head and an ink jet recording apparatus that eject ink droplets by displacement of a piezoelectric element.

[0002]

2. Description of the Related Art A part of a pressure generating chamber communicating with a nozzle opening for discharging ink droplets is constituted by a vibrating plate, and the vibrating plate is deformed by a piezoelectric element to pressurize the ink in the pressure generating chamber to pass through the nozzle opening. Two types of ink jet recording heads that eject ink droplets have been commercialized, one using a longitudinal vibration mode piezoelectric actuator that expands and contracts in the axial direction of the piezoelectric element, and the other using a flexural vibration mode piezoelectric actuator. ing.

In the former method, the volume of the pressure generating chamber can be changed by bringing the end face of the piezoelectric element into contact with the diaphragm, so that a head suitable for high-density printing can be manufactured. There is a problem in that a difficult process of cutting into a comb shape in accordance with the arrangement pitch of the openings and an operation of positioning and fixing the cut piezoelectric element in the pressure generating chamber are required, and the manufacturing process is complicated.

On the other hand, in the latter, a piezoelectric element 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. In addition, there is a problem that a certain area is required due to the use of flexural vibration, and 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 the piezoelectric material layer is cut into a shape corresponding to the pressure generating chambers by a lithography method, and a piezoelectric element is formed so as to be independent for each pressure generating chamber.

This eliminates the need for attaching the piezoelectric element to the vibration plate, which not only allows the piezoelectric element to be manufactured by a precise and simple method such as lithography, but also reduces the thickness of the piezoelectric element. There is an advantage that it can be made thin and can be driven at high speed.

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.

In any case, such an ink jet recording head requires a semiconductor integrated circuit (IC) or the like for driving a piezoelectric element, and is mounted near the ink jet recording head. A mounting portion for connecting an external wiring extending from the IC is provided at an end of the electrode wiring extending from the piezoelectric element, and the external wiring is connected to the mounting portion with an adhesive or the like. Thus, the piezoelectric element and the IC are connected.

[0009]

However, when an external wiring is connected to the mounting portion with an adhesive, the area of the mounting portion becomes large because the adhesive is protruded in a large amount.
The space for the mounting portion is a problem in reducing the size of the recording head.

[0010] Such a problem also exists in any device equipped with an actuator having a similar piezoelectric element.

In view of such circumstances, an object of the present invention is to provide an actuator device, an ink jet recording head, and an ink jet recording device which are miniaturized by saving space in a mounting portion.

[0012]

According to a first aspect of the present invention for solving the above-mentioned problems, a lower electrode is provided on one surface of a substrate having a cavity formed thereon via a diaphragm, and the lower electrode is provided on the lower electrode. In an actuator device including a piezoelectric layer and a piezoelectric element having an upper electrode provided on a surface of the piezoelectric layer, a region of the substrate on one side in a longitudinal direction of the piezoelectric element is extended from the piezoelectric element. A connection portion for electrically connecting the electrode wiring and the external wiring is provided, and the external wiring is a mounting portion fixed to the substrate, and the mounting portion is provided on the substrate in a region corresponding to the mounting portion. Is an actuator device provided with a concave portion obtained by removing a part of the substrate.

In the first aspect, when the external wiring is fixed to the mounting portion with an adhesive or the like, the adhesive does not enter the concave portion and does not spread unnecessarily, so that the area of the mounting portion is reduced.

A second aspect of the present invention is the actuator device according to the first aspect, wherein the recess is provided at an end of the surface of the substrate on the mounting portion side.

In the second aspect, the adhesive enters the concave portion particularly at the end of the substrate, and the area of the mounting portion is reduced.

According to a third aspect of the present invention, in the second aspect, the concave portion is formed in a region not corresponding to the connection portion at substantially the same pitch as an adjacent connection portion. Actuator device.

According to the third aspect, since no concave portion is formed in the region corresponding to the connection portion, the external wiring and the electrode wiring are electrically reliably connected.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the concave portion is provided in a region corresponding to both sides in the width direction of the connecting portion. It is in.

In the fourth aspect, since the concave portion is provided at the center of the mounting portion, the spread of the adhesive is suppressed as a whole, and the area of the mounting portion is reduced.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the concave portion is provided in a region corresponding to both widthwise sides near the end of the electrode wiring on the connection portion side. The actuator device is characterized in that:

In the fifth aspect, the spread of the adhesive is suppressed particularly on the tip end side of the external wiring, and the area of the mounting portion is reduced.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, a nozzle forming member having a nozzle opening communicating with the cavity is joined to the other surface of the substrate. The feature is the ink jet recording head.

In the sixth aspect, since the area of the mounting portion is reduced, it is possible to realize an ink jet recording head that is reduced in size and cost.

According to a seventh aspect of the present invention, in the sixth aspect, the cavity is formed in a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric element is formed by a thin film and a lithography method. An ink jet recording head is provided.

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

According to an eighth aspect of the present invention, there is provided an ink jet recording apparatus including the ink jet recording head according to the sixth or seventh aspect.

According to the eighth aspect, it is possible to realize an ink jet recording apparatus in which the cost is reduced by downsizing the head.

[0028]

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

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

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,
The pressure generating chambers 12 divided by the plurality of partition walls 11 are arranged in parallel in the width direction, and communicate with a reservoir portion of a reservoir forming substrate described later on the outside in the longitudinal direction to become a common ink chamber of each pressure generating chamber 12. A communication portion 13 that forms a part of the reservoir 100 is formed, and an ink supply port 14 that connects the pressure generating chambers 12 and the communication portion 13 with a constant fluid resistance is formed between the pressure generation chambers 12 and the communication portion 13.

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

In this embodiment, the long side of each pressure generating chamber 12 is formed by the first (111) plane, and the short side is formed by the second (111) plane. The pressure generating chamber 12 is provided on the flow path forming substrate 1.
It is formed by etching until it reaches the elastic film 50 almost through 0. Here, the elastic film 50 is
The amount attacked by the alkaline solution for etching the silicon single crystal substrate is extremely small. Each ink supply port 14 communicating with one end of each pressure generating chamber 12 is formed shallower than the pressure generating chamber 12. That is, the ink supply port 14
Is formed by etching (half-etching) the silicon single crystal substrate halfway in the thickness direction. Note that the half etching is performed by adjusting the etching time.

On the opening side of the flow path forming substrate 10,
A nozzle plate 16 in which a nozzle opening 15 communicating with the ink supply port 14 of each pressure generating chamber 12 is formed is fixed through an adhesive or a heat welding film. The thickness of the nozzle plate 16 is, for example, 0.1 to 1
mm, the coefficient of linear expansion is 300 ° C. or less, for example, 2.5 to
It is made of 4.5 [× 10 ⁻⁶ / ° C.] glass ceramic or non-rusting steel. The nozzle plate 16 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 nozzle plate 16 is used to
And may be formed of a material having substantially the same thermal expansion coefficient. In this case, since the deformation of the flow path forming substrate 10 and the nozzle plate 16 due to heat becomes substantially the same, a thermosetting adhesive or the like can be used, and the two can be easily joined.

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 15 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 15 need to be formed with a diameter of several tens of μm with high accuracy.

On the other hand, the lower electrode film 60 having a thickness of, for example, about 0.2 μm and the piezoelectric film having a thickness of, for example, about 1 μm are formed on the elastic film 50 on the side opposite to the opening surface of the flow path forming substrate 10. Body membrane 7
0 and an upper electrode film 80 having a thickness of, for example, about 0.1 μm,
0. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric film 70, and the upper electrode film 80. Generally, one of the electrodes of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric film 70 are patterned for each pressure generating chamber 12. Here, a portion which is constituted by one of the patterned electrodes and the piezoelectric film 70 and in which a piezoelectric strain is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion 320. In the present embodiment, the lower electrode film 60 is used as a common electrode of the piezoelectric element 300 and the upper electrode film 80 is used as an individual electrode of the piezoelectric element 300. In any case, the piezoelectric active portion is formed for each pressure generating chamber. Here, the piezoelectric element 300 and a vibration plate that generates displacement by driving the piezoelectric element 300 are collectively referred to as a piezoelectric actuator. In the example described above, the elastic film 50 and the lower electrode film 6
Although 0 functions as a diaphragm, the lower electrode film may also serve as an elastic film.

The piezoelectric element 300 of the flow path forming substrate 10
On the side, a reservoir forming substrate 20 having a reservoir portion 21 constituting at least a part of the reservoir 100 is joined. This reservoir portion 21 is basically formed in the width direction of the pressure generating chamber 12 so as to penetrate the reservoir forming substrate 20 in the thickness direction, and as described above, the communication portion of the flow path forming substrate 10. The reservoir 100 communicates with the pressure generating chamber 13 and serves as a common ink chamber for each of the pressure generating chambers 12.

As the reservoir forming substrate 20, it is preferable to use a material having substantially the same coefficient of thermal expansion as that of the flow path forming substrate 10, such as glass or ceramic material. It was formed using a silicon single crystal substrate of the same material as that of No. 10. As a result, as in the case of the nozzle plate 16 described above, even when both are bonded at a high temperature using a thermosetting adhesive, both can be securely bonded, and the manufacturing process can be simplified. Can be.

Further, a sealing film 3 is formed on the surface of the reservoir forming substrate 20 opposite to the surface on which the reservoir forming substrate 20 is bonded to the flow path forming substrate 10.
1 and a fixed board 32, a compliance board 30
Are joined. Here, the sealing film 31 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm), and one side of the reservoir 21 is sealed by the sealing film 31. Has been stopped. The fixing plate 32 is formed of a hard material such as a metal (for example, stainless steel (SUS) having a thickness of 30 μm). Since a region of the fixing plate 32 facing the reservoir 100 is an opening 33 completely removed in the thickness direction, one surface of the reservoir 100 is sealed with only the sealing film 31 having flexibility. The flexible portion 23 is deformable by a change in internal pressure, and the flexible portion 23 maintains the internal pressure of the reservoir 100 uniformly.

An ink inlet 25 for supplying ink to the reservoir 100 is formed on the compliance substrate 30 substantially outside the longitudinal center of the reservoir 100. Further, the reservoir forming substrate 20 is provided with an ink introduction path 26 that communicates the ink introduction port 25 with the side wall of the reservoir 100. In the present embodiment, the ink is supplied to the reservoir 100 by one ink inlet 25 and the ink inlet path 26. However, the present invention is not limited to this. For example, according to a desired ink supply amount, A plurality of ink introduction ports and ink introduction paths may be provided, or the opening area of the ink introduction ports may be increased to enlarge the ink flow path.

The piezoelectric element 3 of the reservoir forming substrate 20
In a region opposed to the piezoelectric element 300, a piezoelectric element holding portion 24 capable of sealing the space is provided with a space that does not hinder the movement of the piezoelectric element 300, and at least the piezoelectric active portion 320 of the piezoelectric element 300 is provided. Are sealed in the piezoelectric element holding portion 24. Note that, in the present embodiment, the piezoelectric element holding section 24 includes a plurality of piezoelectric elements 3 arranged in parallel in the width direction.
It is formed in a size to cover 00.

In the present embodiment, the piezoelectric film 70 and the upper electrode film 80 of the piezoelectric element 300 sealed by the piezoelectric element holding section 24 are basically the pressure generating chambers 1.
2 are patterned. On the other hand, the lower electrode film 60
Is provided over a region corresponding to the plurality of pressure generating chambers 12 arranged in parallel, and is patterned on one end side in the longitudinal direction of the pressure generating chamber 12 inside the region corresponding to the pressure generating chamber 12. The upper electrode film 80 of the piezoelectric active portion 320
Is connected to one end of a lead electrode 110 for applying a voltage to the upper electrode film 80.
Numeral 0 is a portion that extends on the flow path forming substrate 10 to the outside of the reservoir forming substrate 20 and is a portion where the surface of the flow path forming substrate 10 on the bonding side with the reservoir forming substrate 20 is exposed, for example,
It is connected to an external wiring 40 such as a flexible printed cable (FPC).

Here, as shown in FIG. 3, in the present embodiment, near the end of the flow path forming substrate 10, there is provided a connecting portion 120 to which the external wiring 40 is electrically connected to the lead electrode 110. The vicinity of the connection part 120 is a mounting part 130 to which the external wiring 40 is fixed by an adhesive 41 such as an anisotropic conductive film (ACF). Note that, here, the mounting portion 130 includes the connecting portion 120 to which the lead electrode 110 and the external wiring 40 are electrically connected, and the area covered by the adhesive 41 for fixing the external wiring 40 around the connecting portion 120.
Called.

A plurality of recesses 140 are formed on the flow path forming substrate 10 in areas corresponding to the mounting portions 130 so as to escape the adhesive 41 for fixing the external wiring 40. For example, in the present embodiment, a plurality of recesses 140 are formed by removing a part of the elastic film 50 and a part of the flow path forming substrate 10 at the end on the side where the external wiring 40 is fixed on the flow path forming substrate 10. Have been. In addition, it is preferable that the plurality of recesses 140 are not formed in a region corresponding to the connection portion 120 from the viewpoint of strength or the like. Are provided at substantially the same pitch. That is, the concave portions 140 are formed so as to be located on both sides in the width direction of each connecting portion 120.

The size and shape of the recess 140 are not particularly limited, and may be appropriately determined in consideration of conditions such as the size and shape of the head and the amount of adhesive used. Further, in the present embodiment, one concave portion 140 is provided between the connection portions 120, but the number is not particularly limited. For example, two or more concave portions may be provided between the connection portions 120.

The method of forming the concave portion 140 is not particularly limited. For example, after the piezoelectric element 300 and the pressure generating chamber 12 are formed, a predetermined position of the flow path forming substrate 10 is thickened by a laser or the like. It can be formed by removing a part of the direction.

As described above, by providing the concave portion 140 on the flow path forming substrate 10 in a region corresponding to the mounting portion 130, the external wiring 40 is bonded to the flow path forming substrate 1
When the adhesive 40 is fixed to the upper side, the adhesive 40 does not enter the recess 140, so that the adhesive 40 does not needlessly spread. In particular, in the present embodiment, the spread of the adhesive 41 on the end side of the flow path forming substrate 10 is suppressed. Accordingly, the area of the mounting section 130 is reduced, and the size and cost of the head can be reduced. In addition, since the formation of the concave portion 140 increases the bonding area of the flow path forming substrate 10, the external wiring 40
Can be improved in bonding strength.

The ink jet recording head of this embodiment takes in ink from the ink inlet 25 connected to an external ink supply means (not shown),
After filling the inside from 00 to the nozzle opening 15 with ink, the upper electrode film 80 and the lower electrode corresponding to the pressure generating chamber 12 via the lead electrode 110 in accordance with a recording signal from an external drive circuit (not shown). A voltage is applied between the film 60 and the elastic film 50, the lower electrode film 60, and the piezoelectric film 70.
Is deformed, the pressure in each pressure generating chamber 12 increases, and ink droplets are ejected from the nozzle opening 15.

In this embodiment, a plurality of recesses 14 are provided at the end of the flow path forming substrate 10 in the region corresponding to the mounting portion 130.
Although 0 is provided, the present invention is not limited to this. For example,
As shown in FIG. 4, the connecting portions 120 may be provided on the flow path forming substrate 10 in regions opposed to both sides in the width direction. As described above, the concave portion 14 is provided near the center of the mounting portion 130.
By forming 0, the spread of the adhesive 41 over the entire mounting portion 130 is suppressed. Further, for example, as shown in FIG. 5, the lead electrode 110 may be provided in a region in the vicinity of both ends in the width direction in the vicinity of the end portion on the connection portion 120 side.
This suppresses the spread of the adhesive 41 particularly on the tip end side of the external wiring.

In any case, the concave portion 140 is
In this case, the adhesive 41 for fixing the external wiring 40 flows into these recesses 140,
Useless spreading of the adhesive 41 is suppressed.

(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 the above-described embodiment, the type in which the reservoir forming substrate 20 having the reservoir 100 together with the pressure generating chamber 12 is joined to the flow path forming substrate 10 has been described. However, the present invention is not limited to this. May be joined to the flow path forming substrate 10 by forming a flow path unit formed of a separate member.

In the above-described embodiment, a thin-film type ink jet recording head manufactured by applying a film forming and lithography process has been described as an example. However, the present invention is not limited to this. The present invention can also be applied to a thick-film type ink jet recording head or the like formed by a method such as sticking.

The ink jet recording head of the embodiment described above constitutes a part of a recording head unit having an ink flow path communicating with an ink cartridge and the like, and is mounted on an ink jet recording apparatus. FIG.
FIG. 2 is a schematic view illustrating an example of the ink jet recording apparatus.

As shown in FIG. 6, the recording head units 1A and 1B having ink jet recording heads are provided with detachable cartridges 2A and 2B constituting ink supply means.
The carriage 3 on which B is mounted is provided movably in the axial direction on a carriage shaft 5 attached to the apparatus main body 4. The recording head units 1A and 1B are, for example,
Each of them ejects a black ink composition and a color ink composition.

The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and a timing belt 7 (not shown), so that the carriage 3 on which the recording head units 1A and 1B are mounted moves along the carriage shaft 5. Moved. On the other hand, a platen 8 is provided on the apparatus main body 4 along the carriage shaft 5, and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller (not shown), is wound around the platen 8. It is designed to be transported.

[0058]

As described above, according to the present invention, the adhesive for fixing the external wiring is formed on the flow path forming substrate in the region corresponding to the mounting portion for connecting the lead electrode extended from the piezoelectric element and the external wiring. A concave portion is provided to allow the agent to escape. As a result, wasteful spread of the adhesive is suppressed, the area of the mounting portion is reduced, and the size and cost of an actuator such as an ink jet recording head can be reduced. In addition, since the bonding area is increased by the concave portion, there is an effect that the bonding strength can be improved.

[Brief description of the drawings]

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

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

FIGS. 3A and 3B are a perspective view and a cross-sectional view illustrating a mounting portion of the inkjet recording head according to the first embodiment of the present invention.

FIG. 4 is a plan view and a cross-sectional view illustrating another example of the inkjet recording head according to the first embodiment of the present invention.

FIG. 5 is a plan view and a cross-sectional view illustrating another example of the inkjet recording head according to the first embodiment of the present invention.

FIG. 6 is a schematic diagram of an ink jet recording apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 flow path forming substrate 12 pressure generating chamber 15 nozzle opening 16 nozzle plate 20 reservoir forming substrate 24 piezoelectric element holding unit 30 compliance substrate 40 external wiring 41 adhesive 60 lower electrode film 70 piezoelectric film 80 upper electrode film 100 reservoir 110 lead electrode Reference Signs List 120 connection part 130 mounting part 140 concave part 300 piezoelectric element 320 piezoelectric active part

Claims (8)

[Claims] 1. A substrate having a cavity, on one surface of which a lower electrode is provided via a diaphragm, a piezoelectric layer provided on the lower electrode, and an upper electrode provided on the surface of the piezoelectric layer. In an actuator device including a piezoelectric element, a region of the substrate on one side in a longitudinal direction of the piezoelectric element is:
A connection portion is provided for electrically connecting an electrode wire and an external wire extended from the piezoelectric element, and the external wire is a mounting portion fixed on the substrate, and the mounting portion corresponds to the mounting portion. An actuator device, characterized in that a concave portion obtained by removing a part of the substrate is provided on the substrate in a region where the actuator is to be operated. 2. The actuator device according to claim 1, wherein the recess is provided at an end of the surface of the substrate on the mounting portion side. 3. The actuator device according to claim 2, wherein the concave portion is formed in a region not corresponding to the connection portion at a pitch substantially equal to a pitch between adjacent connection portions. 4. The actuator device according to claim 1, wherein the concave portion is provided in a region corresponding to both sides in the width direction of the connecting portion. 5. The actuator according to claim 1, wherein the recess is provided in a region corresponding to both widthwise sides near an end of the electrode wiring on the connection portion side. apparatus. 6. The ink jet recording head according to claim 1, wherein a nozzle forming member having a nozzle opening communicating with the cavity is joined to the other surface of the substrate. 7. The method according to claim 6, wherein the cavity is formed in the silicon single crystal substrate by anisotropic etching.
An ink jet recording head, wherein each layer of the piezoelectric element is formed by a thin film and a lithography method. 8. An ink jet recording apparatus comprising the ink jet recording head according to claim 6.