JP2003251801A - Inkjet recording head, its manufacturing method and inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording head which can prevent failure of piezoelectric element due to the external environment such as moisture, and provide a manufacturing method therefor and an inkjet recorder. <P>SOLUTION: In the inkjet recording head which has a channel forming substrate 10 where pressure generation chambers 12 are to be formed to communicate with nozzle openings, and piezoelectric elements 300 set to one face of the channel forming substrate 10 for generating a pressure change inside the pressure generation chambers 12, there is provided a sealing substrate 30 which has a piezoelectric element holding part 31 joined to the piezoelectric elements 300 side of the channel forming substrate 10 for securing a space such that the motion of the piezoelectric elements 300 is not hindered, and at least one communication hole 32 for making the piezoelectric element holding part 31 communicate with the outside. A driving IC 110 for driving piezoelectric elements 300 is joined to a region including an opening of the communication hole 32 of the sealing substrate 30, and moreover, the communication hole 32 is sealed by this driving IC 110, whereby the piezoelectric element holding part 31 is kept surely in a sealing state. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a vibrating plate which constitutes a part of a pressure generating chamber communicating with a nozzle opening for ejecting ink droplets. The present invention relates to an inkjet recording head that ejects ink droplets by a method, a method for manufacturing the same, and an inkjet recording device.

[0002]

2. Description of the Related Art A part of a pressure generating chamber that communicates with a nozzle opening for ejecting ink droplets is composed of a vibrating plate, and the vibrating plate is deformed by a piezoelectric element to pressurize ink in the pressure generating chamber to eject it from the nozzle opening. Two types of inkjet recording heads that eject ink droplets have been put into practical use: one that uses a longitudinal vibration mode piezoelectric actuator that expands and contracts in the axial direction of a piezoelectric element, and one that uses a flexural vibration mode piezoelectric actuator. ing.

The former allows the volume of the pressure generating chamber to be changed by bringing the end face of the piezoelectric element into contact with the vibrating plate, and a head suitable for high-density printing can be manufactured. There is a problem in that the manufacturing process is complicated because a difficult process of matching the array pitch of the openings and cutting into comb teeth or a work of positioning and fixing the cut piezoelectric element in the pressure generating chamber are required.

On the other hand, in the latter, the piezoelectric element can be formed on the vibration plate by a relatively simple process of sticking a green sheet of a piezoelectric material in conformity with the shape of the pressure generating chamber and firing it. 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 eliminate the disadvantage of the latter recording head, a uniform piezoelectric material layer is formed over the entire surface of the diaphragm by a film forming technique as disclosed in Japanese Patent Laid-Open No. 5-286131. It has been proposed that the piezoelectric material layer is cut into a shape corresponding to the pressure generating chamber by a lithographic method and a piezoelectric element is formed so as to be independent for each pressure generating chamber.

According to this, the work of attaching the piezoelectric element to the diaphragm becomes unnecessary, and not only the piezoelectric element can be built by a precise and simple method such as a lithography method, but also the thickness of the piezoelectric element can be reduced. It has the advantage that it can be made thin and can be driven at high speed.

[0007]

However, in the case where the piezoelectric element is formed by sputtering the piezoelectric material as described above, the piezoelectric element is thin when it is driven at substantially the same voltage as that formed by firing the green sheet. When a high electric field is applied to absorb moisture in the atmosphere, the leak current between the drive electrodes is apt to increase, which eventually leads to dielectric breakdown.

In view of such circumstances, it is an object of the present invention to provide an ink jet recording head, a method of manufacturing the same, and an ink jet recording apparatus in which malfunctions caused by the external environment such as moisture of the piezoelectric element are prevented. To do.

[0009]

According to a first aspect of the present invention for solving the above-mentioned problems, there is provided a flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening is formed, and one surface side of the flow path forming substrate. In an ink jet recording head provided with a piezoelectric element for generating a pressure change in the pressure generating chamber, the ink jet recording head is bonded to the piezoelectric element side of the flow path forming substrate and does not hinder the movement of the piezoelectric element. A sealing substrate having a piezoelectric element holding portion that secures a space and at least one communication hole that connects the piezoelectric element holding portion and the outside;
A drive IC for driving the piezoelectric element is bonded to a region including an opening of the communication hole of the sealing substrate, and the drive IC.
According to another aspect of the invention, there is provided an ink jet recording head, wherein the communication hole is sealed.

According to the first aspect, the piezoelectric element can be relatively easily sealed in the piezoelectric element holding portion, and the ink jet recording head can be realized in which the malfunction of the piezoelectric element due to the external environment is prevented. Further, since the communication hole may be formed in a region of the sealing substrate where the drive IC is joined,
The head can be downsized.

According to a second aspect of the present invention, in the first aspect, the drive IC is bonded to the sealing substrate with an adhesive, and the adhesive is filled in the communication hole. And an inkjet recording head.

In the second aspect, since the communication hole is reliably sealed by the adhesive, the inside of the piezoelectric element holding portion can be easily and surely sealed.

A third aspect of the present invention is the ink jet recording head according to the second aspect, characterized in that the piezoelectric element holding portion is sealed at an atmospheric pressure lower than atmospheric pressure.

In the third aspect, since a part of the sealing member that seals the communication hole is drawn into the communication hole, the piezoelectric element holding portion can be sealed more reliably.

According to a fourth aspect of the present invention, in the third aspect, a part of the communication hole is constituted by a groove portion formed on a joint surface of the sealing substrate with the flow path forming substrate. An inkjet recording head characterized by the above.

In the fourth aspect, the amount of the sealing member drawn into the communication hole is controlled by adjusting the shape and length of the groove.

A fifth aspect of the present invention is the ink jet recording head according to any one of the first to fourth aspects, characterized in that the piezoelectric element holding portion is filled with a dry fluid.

In the fifth aspect, since the piezoelectric element is held in a dry fluid atmosphere, malfunctions due to changes in the external environment can be prevented more reliably.

A sixth aspect of the present invention is the ink jet recording head according to the fifth aspect, characterized in that the dry fluid is an inert gas.

In the sixth aspect, the piezoelectric element is held in an inert gas atmosphere and is not affected by changes in the external environment.

A seventh aspect of the present invention is the ink jet recording head according to the fifth aspect, characterized in that the dry fluid contains an oxidizing gas.

In the seventh aspect, deterioration of the piezoelectric layer mainly formed of oxide is prevented.

According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the pressure generating chamber is formed in a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric element is formed and formed. The inkjet recording head is characterized by being formed by a lithography method.

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

A ninth aspect of the present invention is an ink jet recording apparatus including the ink jet recording head according to any one of the first to eighth aspects.

According to the ninth aspect, it is possible to realize an ink jet recording apparatus with improved head reliability.

A tenth aspect of the present invention is a flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening is formed, and a pressure change in the pressure generating chamber provided on one surface side of the flow path forming substrate. In a method of manufacturing an ink jet recording head including a piezoelectric element for generating a piezoelectric element, a piezoelectric element holding portion that secures a space on the piezoelectric element side of the flow path forming substrate that does not hinder the movement of the piezoelectric element, and the piezoelectric element. A first step of forming a bonded body by bonding a bonded substrate having a communication hole that communicates the element holding portion with the outside, and arranging the bonded body in a predetermined sealed space and reducing the humidity of this sealed space. In the second step, a drive IC for driving the piezoelectric element is adhered to a region including the opening of the communication hole on the sealing substrate forming the bonded body, and the opening of the communication hole is formed by the drive IC. Sealed In the manufacturing method of the ink jet recording head characterized in that it comprises a third step of.

In the tenth aspect, since the communication hole is sealed at the same time as the driving IC is bonded, the piezoelectric element holding portion is easily and surely sealed, and the manufacturing process is simplified.

An eleventh aspect of the present invention is the method of manufacturing an ink jet recording head according to the tenth aspect, characterized in that the sealed space is evacuated in the second step.

In the eleventh aspect, the inside of the piezoelectric element holding portion is held at low humidity. Moreover, since the adhesive is drawn into the communication hole when the drive IC is bonded, the communication hole is more reliably sealed.

The twelfth aspect of the present invention is the tenth or eleventh aspect.
In the above aspect, in the second step, there is provided a method for manufacturing an ink jet recording head, characterized in that the sealed space is filled with a dry fluid.

According to the twelfth aspect, since the piezoelectric element holding portion is filled with the dry fluid, the piezoelectric element is held in the dry fluid atmosphere, and malfunction of the piezoelectric element due to the external environment is prevented.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on embodiments.

(Embodiment 1) FIG. 1 is an exploded perspective view showing an outline of an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 is a plan view and a sectional view of 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, and one surface thereof is made of silicon dioxide previously formed by thermal oxidation. An elastic film 50 of 1 to 2 μm is formed.

In this flow path forming substrate 10, a pressure generating chamber 1 defined by a plurality of partition walls 11 is formed by anisotropically etching a silicon single crystal substrate from one side thereof.
2 are juxtaposed in the width direction. Further, a communication portion 13 that communicates with a reservoir portion 35 of the sealing substrate 30 described later is formed on the outer side in the longitudinal direction. Also, this communication part 1
3 is connected to one end of each pressure generating chamber 12 in the longitudinal direction via an ink supply passage 14.

Here, the anisotropic etching is performed by utilizing the difference in etching rate of the silicon single crystal substrate. For example, in this embodiment, the silicon single crystal substrate is set to K.
When it is dipped in an alkaline solution such as OH, it is gradually eroded and the first (111) plane perpendicular to the (110) plane and the first (111) plane
Forms an angle of about 70 degrees with the (111) plane of
A second (111) plane that makes an angle of about 35 degrees with the (0) plane appears, and the etching rate of the (111) plane is about 1/180 of the etching rate of the (110) plane. Is done using. By such anisotropic etching, it is possible to perform precision machining based on the depth machining of the parallelogram shape formed by the two first (111) planes and the two diagonal second (111) planes. The pressure generating chambers 12 can be arranged in 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 in the flow path forming substrate 1
It is formed by etching through almost 0 to reach the elastic film 50. Here, the elastic film 50 is
The amount of the alkaline solution that etches the silicon single crystal substrate is extremely small. Further, each ink supply passage 14 communicating with one end of each pressure generation chamber 12 is formed shallower than the pressure generation chamber 12, and keeps the flow resistance of the ink flowing into the pressure generation chamber 12 constant. That is, the ink supply path 14 is formed by etching the silicon single crystal substrate halfway in the thickness direction (half etching). The half etching is performed by adjusting the etching time.

The thickness of the flow path forming substrate 10 in which the pressure generating chambers 12 and the like are formed is preferably selected in accordance with the density at which the pressure generating chambers 12 are arranged. For example, 180 per inch (180dp
When arranging the pressure generating chambers 12 to about i), the thickness of the flow path forming substrate 10 is preferably about 180 to 280 μm, and more preferably about 220 μm. Further, when the pressure generating chambers 12 are arranged at a relatively high density of, for example, about 360 dpi, the thickness of the flow path forming substrate 10 is preferably 100 μm or less. This is because the array density can be increased while maintaining the rigidity of the partition walls 11 between the adjacent pressure generating chambers 12.

A nozzle plate 20 having a nozzle opening 21 communicating with each pressure generating chamber 12 on the side opposite to the ink supply path 14 is provided on the opening side of the flow path forming substrate 10 with an adhesive or heat welding. It is fixed via a film or the like. The nozzle plate 20 has a thickness of, for example, 0.1 to 1
mm, a coefficient of linear expansion of 300 ° C. or less, for example, 2.5 to
It is made of glass ceramics of 4.5 [× 10 ⁻⁶ / ° C.] or rust-free steel. The nozzle plate 20 entirely covers one surface of the flow path forming substrate 10 with one surface, and also serves as a reinforcing plate that protects the silicon single crystal substrate from impact and external force. Further, the nozzle plate 20 is used as the flow path forming substrate 10.
It may be made of a material having substantially the same thermal expansion coefficient. In this case, since the flow path forming substrate 10 and the nozzle plate 20 have substantially the same deformation due to heat, they can be easily joined using a thermosetting adhesive or the like.

Here, the size of the pressure generating chamber 12 that applies the ink drop ejection pressure to the ink and the size of the nozzle opening 21 that ejects the ink drop depend on the amount of the ejected ink drop, the ejection speed, and the ejection frequency. Optimized. For example,
When recording 360 ink drops per inch, it is necessary to accurately form the nozzle openings 21 with a diameter of several tens of μm.

On the other hand, a thickness of, for example, about 0.2 μm is formed on the elastic film 50 on the side opposite to the opening surface of the flow path forming substrate 10.
The lower electrode film 60, the piezoelectric layer 70 having a thickness of, for example, about 1 μm, and the upper electrode film 80 having a thickness of, for example, about 0.1 μm are laminated in a process described below to form the piezoelectric element 30.
Configures 0. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 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 layer 70 are patterned for each pressure generating chamber 12. Further, here, a portion which is composed of one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric strain is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. In the present embodiment, the lower electrode film 60 is the common electrode of the piezoelectric element 300, and the upper electrode film 80 is the individual electrode of the piezoelectric element 300.
There is no problem in reversing this due to the driving circuit and wiring.
In any case, the piezoelectric active portion is formed for each pressure generating chamber. Further, here, the piezoelectric element 300 and the vibration plate that is displaced by the driving of the piezoelectric element 300 are collectively referred to as a piezoelectric actuator.

Further, a lead electrode 90 made of, for example, gold (Au) is extended from the vicinity of one end in the longitudinal direction of the upper electrode film 80 of the piezoelectric element 300 to the vicinity of the end of the flow path forming substrate 10. The lead electrode 90 is electrically connected to a drive IC, which will be described later, in the vicinity of the end of the lead electrode 90.

Further, the piezoelectric element 300 of the flow path forming substrate 10
On the side, a sealing substrate 30 having a piezoelectric element holding portion 31 capable of sealing the space in a state in which a space that does not hinder the movement of the piezoelectric element 300 is secured is adhered.

As the sealing substrate 30, for example, glass,
It is preferable to use a material having substantially the same coefficient of thermal expansion as the flow path forming substrate 10 such as a ceramic material. In the present embodiment, a silicon single crystal substrate made of the same material as the flow path forming substrate 10 is used.

On this sealing substrate 30, the piezoelectric element holding portion 3 is provided.
1 is provided with a communication hole 32 that communicates with the outside, and in the present embodiment, a part of the communication hole 32 is configured by a groove portion 33 provided on the joint surface of the sealing substrate 30 with the flow path forming substrate 10. Has been done.

The piezoelectric element 30 is provided on the sealing substrate 30.
A drive IC 110 for driving 0 is fixed by an adhesive 120, and the opening of the communication hole 32 is sealed by the drive IC 110. This drive I
C110 is electrically connected to each lead electrode 90 by a drive wiring (not shown) formed of a bonding wire or the like extended through a through hole 34 provided outside the piezoelectric element holding portion 31 of the sealing substrate 30. Connected to.

In the communication hole 32 thus sealed by the drive IC 110, the drive IC will be described in detail later.
An adhesive 120 for adhering 110 to the sealing substrate 30 has entered, and the communication hole 32 is completely sealed by this adhesive 120.

The piezoelectric element holding portion 31 is filled with a dry fluid such as an inert gas, and is sealed at a pressure lower than atmospheric pressure. As a result, the piezoelectric element 300 is reliably sealed in the dry fluid atmosphere in the piezoelectric element holding portion 31 and completely shielded from the external environment.

As the dry fluid, a reducing gas can be used in addition to the inert gas, but conversely, by containing an oxidizing gas, an environment for preventing the deterioration of the piezoelectric layer can be formed. it can. Moreover, when using such an inert gas, it is desirable to make the vapor pressure (partial pressure) of the water in the inert gas as low as possible.

Now, the procedure for filling the piezoelectric element holding portion 31 with the dry fluid and sealing the communication hole 32 will be described.

First, the head is placed in a sealed space filled with a predetermined dry fluid 130 and the space is depressurized. At this time, the pressure inside the piezoelectric element holding portion 31 is also reduced, and as shown in FIG. 3A, the air 140 inside the piezoelectric element holding portion 31 is discharged to the outside through the communication hole 32. Then, by further introducing the drying fluid 130 into the sealed space, as shown in FIG.
As shown in (b), the drying fluid 13 is passed through the communication hole 32.
0 flows into the piezoelectric element holding portion 31 and is filled therein. That is, the air 140 in the piezoelectric element holding portion 31 and the dry fluid 1
30 is replaced.

Next, as shown in FIG. 4A, the drive IC 110 is bonded onto the sealing substrate 30 with the adhesive 120. Then, by returning the inside of the sealed space to normal pressure, as shown in FIG.
As shown in (b), a part of the adhesive (uncured resin) 120 is drawn into the communication hole 32. The adhesive 120
The amount of pulling in can be controlled by adjusting the shape and length of the groove 33.

Then, by curing the adhesive 120, the drive IC 110 is fixed on the sealing substrate 30 and the communication hole 32 is completely sealed. This allows
The piezoelectric element holding portion 31 is securely sealed while being filled with a dry fluid.

In the configuration of the present embodiment described above, the communication hole 32 that connects the piezoelectric element holding portion 31 and the outside is sealed by the drive IC 110 bonded to the sealing substrate 30, so the communication hole 32 is formed. Can be reliably sealed. That is, since the drive IC 110 seals a relatively wide range of the peripheral portion of the communication hole 32, the communication hole 32 can be reliably sealed. Therefore, the piezoelectric element 3
00, in particular, destruction of the piezoelectric layer 70 due to the external environment can be reliably prevented.

In addition, the opening of the communication hole 32 is the sealing substrate 30.
It suffices that it is provided in a region to which the drive IC 110 of FIG. 2 is joined, and it is not necessary to secure a region for forming the communication hole 32 other than a region of the sealing substrate 30 to which the drive IC 110 is joined. Can be downsized, and the head can be downsized.

Furthermore, since the step of bonding the drive IC 110 to the sealing substrate 30 and the step of sealing the communication hole 32 can be performed simultaneously, the manufacturing process can be simplified and the manufacturing cost can be reduced. .

A plurality of pressure generating chambers 12 are provided in a region of the sealing substrate 30 corresponding to the communicating portion 13 of the flow path forming substrate 10.
A reservoir portion 35 that forms at least a part of the reservoir 100 that is a common ink chamber is formed. In this embodiment, the reservoir portion 35 penetrates the sealing substrate 30 in the thickness direction and is formed in the width direction of the pressure generating chamber 12. Then, the reservoir portion 35 becomes the flow path forming substrate 1.
The reservoir 100 is formed by communicating with the communication portion 13 of 0 through the through hole 51 formed in the elastic film 50.

Further, the sealing film 4 is formed on the sealing substrate 30.
Compliance board 40 consisting of 1 and fixing plate 42
Are joined. Here, the sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm), and the sealing film 41 seals one surface of the reservoir portion 35. It has been stopped. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm).
Etc.). The area of the fixing plate 42 facing the reservoir 100 is the opening 4 completely removed in the thickness direction.
Therefore, the one surface of the reservoir 100 is sealed only by the flexible sealing film 41.

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

For example, in the above embodiment, the piezoelectric element holding portion 31 was filled with the dry fluid, but of course,
Air may be present without being filled with dry fluid,
It is preferable to reduce the water content in the air.

Further, for example, in the above-described embodiment, one communication hole 32 that communicates the piezoelectric element holding portion 31 and the outside is provided, but the present invention is not limited to this, and, of course, a plurality of communication holes may be provided. Good.

Further, for example, in the above-mentioned embodiment, the thin film type ink jet recording head manufactured by applying the film formation and the lithographic process is taken as an example, but the present invention is not limited to this and, for example, The present invention can also be applied to a thick film type ink jet recording head formed by a method such as attaching a green sheet.

The ink jet recording head of each of these embodiments constitutes a part of a recording head unit having an ink flow path communicating with an ink cartridge or the like, and is mounted on an ink jet recording apparatus. Figure 5
It is a schematic diagram showing an example of the ink jet type recording device.

As shown in FIG. 5, in the recording head units 1A and 1B having an ink jet recording head, the cartridges 2A and 2B constituting the ink supply means are detachably provided, and the recording head units 1A and 1B.
The carriage 3 on which B is mounted is provided on a carriage shaft 5 attached to the apparatus body 4 so as to be movable in the axial direction. The recording head units 1A and 1B are, for example,
The black ink composition and the color ink composition are respectively discharged.

The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears (not shown) and the timing belt 7, so that the carriage 3 having the recording head units 1A and 1B mounted thereon follows the carriage shaft 5. Be 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 feed roller (not shown), is conveyed on the platen 8. It is like this.

[0067]

As described above, according to the present invention, since the piezoelectric element is sealed in the piezoelectric element holding portion filled with the dry fluid, the piezoelectric element, particularly the piezoelectric layer, is prevented from being damaged due to the external environment. can do. Further, since the communication hole communicating with the piezoelectric element holding portion is sealed with the uncured resin, the piezoelectric element holding portion can be relatively easily and reliably sealed.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing an inkjet recording head according to a first embodiment of the invention.

2A and 2B are a plan view and a sectional view of the ink jet recording head according to the first embodiment of the invention.

FIG. 3 is a cross-sectional view showing the manufacturing process of the ink jet recording head according to the first embodiment of the invention.

FIG. 4 is a cross-sectional view showing the manufacturing process of the inkjet recording head according to the first embodiment of the invention.

FIG. 5 is a schematic diagram of an inkjet recording apparatus according to an embodiment of the present invention.

[Explanation of symbols]

10 Flow path forming substrate 12 Pressure generation chamber 13 Communication 14 Ink supply path 20 nozzle plate 21 nozzle opening 30 sealing substrate 31 Piezoelectric element holder 32 communication holes 33 Groove 35 Reservoir section 40 compliance board 50 elastic membrane 60 Lower electrode film 70 Piezoelectric layer 80 Upper electrode film 300 Piezoelectric element 110 drive IC 120 adhesive

Claims (12)

[Claims] 1. A flow passage forming substrate in which a pressure generating chamber communicating with a nozzle opening is formed, and a piezoelectric element provided on one surface side of the flow passage forming substrate to generate a pressure change in the pressure generating chamber. In an ink jet recording head provided with, a piezoelectric element holding part that is joined to the piezoelectric element side of the flow path forming substrate to secure a space that does not hinder the movement of the piezoelectric element, the piezoelectric element holding part, and the outside. A sealing substrate having at least one communication hole communicating therewith, and a drive IC for driving the piezoelectric element is bonded to a region including an opening of the communication hole of the sealing substrate, and the drive IC causes An ink jet recording head having a communication hole sealed. 2. The ink jet recording head according to claim 1, wherein the drive IC is bonded to the sealing substrate with an adhesive, and the adhesive is filled in the communication hole. 3. The ink jet recording head according to claim 2, wherein the piezoelectric element holding portion is sealed at a pressure lower than atmospheric pressure. 4. The ink jet recording according to claim 3, wherein a part of the communication hole is formed by a groove formed on a joint surface of the sealing substrate with the flow path forming substrate. head. 5. The ink jet recording head according to claim 1, wherein the piezoelectric element holding portion is filled with a dry fluid. 6. The ink jet recording head according to claim 5, wherein the dry fluid is an inert gas. 7. The ink jet recording head according to claim 5, wherein the dry fluid contains an oxidizing gas. 8. The pressure generating chamber according to claim 1, wherein the pressure generating chamber is formed in a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric element is formed by film formation and a lithography method. An ink jet recording head characterized by being present. 9. An ink jet recording apparatus comprising the ink jet recording head according to claim 1. 10. A flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening is formed, and a piezoelectric element provided on one surface side of the flow path forming substrate to generate a pressure change in the pressure generating chamber. In the method for manufacturing an ink jet recording head provided with, a piezoelectric element holding portion that secures a space on the piezoelectric element side of the flow path forming substrate that does not hinder the movement of the piezoelectric element, the piezoelectric element holding portion, and the outside. A first step of forming a joined body by joining joined substrates having communicating holes communicating with each other, a second step of arranging the joined body in a predetermined sealed space and lowering the humidity of the sealed space, A drive IC for driving the piezoelectric element is adhered to a region including an opening of the communication hole on the sealing substrate forming a bonded body, and the drive I
C. The third step of sealing the opening of the communication hole with C, the method for manufacturing an ink jet recording head. 11. The method of manufacturing an ink jet recording head according to claim 10, wherein in the second step, the sealed space is evacuated. 12. The method for manufacturing an ink jet recording head according to claim 10, wherein the sealed space is filled with a dry fluid in the second step.