JP2002046281A - Ink jet recording head and its manufacturing method and ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording head in which pressure generating chambers can be arranged with high density while enhancing the rigidity of a barrier wall, its manufacturing method and an ink jet recorder. SOLUTION: The ink jet recording head comprises a channel forming substrate 10 of single crystal silicon in which pressure generating chambers 12 communicating with nozzle openings are defined, and a piezoelectric element 300 comprising a lower electrode 60, a piezoelectric layer 70 and an upper electrode 80 provided on one face side of the channel forming substrate 10 through a diaphragm. A bonding substrate 30 of single crystal silicon being bonded to the piezoelectric element 300 side of the channel forming substrate 10 through a sealing member 40 is provided and an integrated circuit 31 is formed integrally in a region facing the piezoelectric element 300 on the side of the substrate 30 being bonded to the channel forming substrate 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure generating chamber which communicates with a nozzle opening for discharging ink droplets, which is constituted by a vibrating plate. TECHNICAL FIELD The present invention relates to an ink jet recording head for ejecting ink droplets by using the method, a method for manufacturing the same, and an ink jet recording apparatus.

[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.

[0007]

However, when a relatively large substrate having a diameter of, for example, about 6 to 12 inches is to be used as a substrate for forming the pressure generating chamber, the thickness of the substrate may be reduced due to problems such as handling. Therefore, the pressure generating chamber must be made deeper.
Therefore, sufficient rigidity cannot be obtained unless the thickness of the partition wall that partitions each pressure generation chamber is increased, and crosstalk occurs,
There is a problem that desired ejection characteristics cannot be obtained.

In view of such circumstances, the present invention provides an ink jet recording head, a method of manufacturing the same, and an ink jet recording apparatus capable of improving the rigidity of the partition wall and arranging the pressure generating chambers at a high density. That is the task.

[0009]

According to a first aspect of the present invention, there is provided a flow path forming substrate made of single-crystal silicon, in which a pressure generating chamber communicating with a nozzle opening is defined; In an ink jet recording head including a lower electrode provided on one surface side of a formation substrate via a vibration plate, a piezoelectric element including a piezoelectric layer and an upper electrode, sealing is provided on the piezoelectric element side of the flow path formation substrate. An integrated circuit is integrally formed in a region opposed to the piezoelectric element on a bonding surface side of the bonding substrate with the flow path forming substrate, the bonding substrate including a single crystal silicon bonded through a member. An ink jet recording head is characterized in that:

In the first aspect, the piezoelectric element and the integrated circuit can be connected relatively easily, and the size of the head can be reduced. Further, since the joining substrate on which the integrated circuit is integrally formed is joined to the flow path forming substrate, the thickness of the flow path forming substrate can be reduced, and the height of the pressure generating chamber can be reduced.

According to a second aspect of the present invention, in the first aspect, a conductive member is connected to one of the lower electrode and the upper electrode constituting the piezoelectric element, and the conductive member is integrated with the integrated device. The ink jet recording head is characterized in that the piezoelectric element and the integrated circuit are electrically connected by contacting a connection wire of a circuit.

In the second aspect, since the conductive member and the connection wiring of the integrated circuit can be brought into contact by joining the flow path forming substrate and the joining substrate, the piezoelectric element and the integrated circuit are electrically connected. Can be easily connected.

According to a third aspect of the present invention, in the first or second aspect, the piezoelectric element is sealed in a space defined by the bonding substrate and the sealing member. Ink-jet recording head.

In the third aspect, since the piezoelectric element is isolated from the external environment, the piezoelectric element is prevented from being broken due to the external environment such as moisture in the atmosphere.

A fourth aspect of the present invention is the ink jet recording head according to any one of the first to third aspects, wherein the sealing member is an adhesive.

In the fourth aspect, the flow path forming substrate and the bonding substrate can be easily bonded by the adhesive.

According to a fifth aspect of the present invention, in any one of the first to third aspects, the sealing member is made of silicon oxide or glass, and the flow path forming substrate and the joining substrate are formed of the sealing member. Characterized in that they are joined by anodic joining via an ink jet recording head.

In the fifth aspect, the flow path forming substrate and the bonding substrate can be easily and reliably bonded.

According to a sixth aspect of the present invention, in any one of the second to fifth aspects, the conductive member has one end connected to the one electrode and the other end fixed to the flow path forming substrate. And a bonding wire.

In the sixth aspect, the piezoelectric element and the integrated circuit are electrically connected via the bonding wire.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the pressure generating chamber is formed by anisotropic etching, and each of the layers constituting the diaphragm and the piezoelectric element is formed. And an ink jet recording head formed by a lithography method.

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 comprising the ink jet recording head according to any one of the first to seventh aspects.

According to the eighth aspect, it is possible to realize an ink jet recording apparatus in which the ink ejection characteristics of the head are improved.

According to a ninth aspect of the present invention, there is provided a flow path forming substrate formed of single crystal silicon and defining a pressure generating chamber communicating with a nozzle opening, and a vibrating plate provided on one side of the flow path forming substrate. For manufacturing an ink jet type recording head, comprising: a piezoelectric element comprising a lower electrode, a piezoelectric layer and an upper electrode provided by way of example; and a bonding substrate made of single crystal silicon bonded to the piezoelectric element side of the flow path forming substrate. A step of laminating and patterning the lower electrode, the piezoelectric layer and the upper electrode via the vibration plate on the flow path forming substrate to form the piezoelectric element, and forming the piezoelectric element on one surface of the bonding substrate. A step of integrally forming an integrated circuit in a region facing the piezoelectric element, and a step of joining the piezoelectric element side of the flow path forming substrate and the integrated circuit side of the joining substrate via a sealing member, The channel type A step of processing the substrate and the bonded substrate to a predetermined thickness, in the manufacturing method of the ink jet recording head, characterized by a step of forming the pressure generating chamber.

In the ninth aspect, the bonding substrate is bonded to the flow path forming substrate, and then the flow path forming substrate is processed to a predetermined thickness. Can be made thinner.

According to a tenth aspect of the present invention, in the ninth aspect, in the step of forming the pressure generating chamber, the pressure generating chamber is formed by etching the flow path forming substrate, and the bonding substrate is formed. And forming a flow path for supplying ink to the pressure generating chamber by etching the pressure generating chamber.

In the tenth aspect, since the pressure generating chamber and the flow path for supplying ink to the pressure generating chamber are formed at the same time, the manufacturing process is simplified.

According to an eleventh aspect of the present invention, in the ninth or tenth aspect, a conductive member having conductivity and having one end connected to one of the lower electrode and the upper electrode constituting the piezoelectric element. When the flow path forming substrate and the bonding substrate are bonded, the piezoelectric element and the integrated circuit are electrically connected by contacting the conductive member and a connection wiring of the integrated circuit. A method for manufacturing an ink jet recording head, characterized in that:

In the eleventh aspect, since the piezoelectric element and the drive circuit are electrically connected at the same time by joining the flow path forming substrate and the joining substrate, the manufacturing process can be simplified. .

According to a twelfth aspect of the present invention, in the eleventh aspect, in the step of forming the pressure generating chamber, the pressure generating chamber is formed by etching the flow path forming substrate, and the bonding substrate is formed. And forming a connection port for connecting the other electrode constituting the piezoelectric element and an external wiring by etching the piezoelectric element.

In the twelfth aspect, since the connection port for connecting the electrode of the piezoelectric element and the external wiring is formed simultaneously with the pressure generating chamber, the manufacturing process is simplified.

According to a thirteenth aspect of the present invention, in any one of the ninth to twelfth aspects, the sealing member is provided on glass, or on a joint surface side of each of the flow path forming substrate and the joint substrate. A method for manufacturing an ink jet recording head, comprising a silicon oxide layer, wherein the flow path forming substrate and the bonding substrate are bonded by anodic bonding via the sealing member.

In the thirteenth aspect, the flow path forming substrate and the bonding substrate can be easily and reliably bonded.

[0035]

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

(Embodiment 1) FIG. 1 is an exploded perspective view showing an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 is a longitudinal view of one pressure generating chamber of the ink jet recording head. It is a figure showing a section structure.

As shown in the figure, the flow path forming substrate 10 is composed of, for example, a single crystal silicon substrate having a thickness of 50 to 150 μm, one surface of which is an opening surface, and the other surface of which is formed of a dioxide previously formed by thermal oxidation. It is made of silicon and has a thickness of 0.
An elastic film 50 having a thickness of 1 to 2 μm is formed.

A pressure generating chamber 12 partitioned by a plurality of partition walls 11 is formed on the opening surface of the flow path forming substrate 10 by anisotropic etching. Further, each pressure generating chamber 12
A reservoir 13, which is a common ink chamber of each pressure generating chamber 12, is formed at one longitudinal end of the ink supply path 14.
Are communicated with the respective pressure generating chambers 12 through the air.

The reservoir 13 and the ink supply path 14 are formed together with the pressure generating chamber 12 by anisotropic etching. The ink supply path 14 is for controlling the flow of ink into and out of the pressure generation chamber 12 and is formed shallower than the pressure generation chamber 12 and the reservoir 13.

Here, in the anisotropic etching, when the single crystal silicon substrate is immersed in an alkaline solution such as KOH, the substrate is gradually eroded and the first (111) plane perpendicular to the (110) plane and the first (111) plane are formed. 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. The amount of the elastic film 50 that is attacked by the alkaline solution for etching the silicon single crystal substrate is extremely small.

A nozzle plate 20 having a nozzle opening 21 communicating with the pressure supply chamber 12 on the opposite side of 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 thickness of the nozzle plate 20 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 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. Further, the nozzle plate 20 is connected to the flow path forming substrate 10.
May be formed of a material having substantially the same thermal expansion coefficient as that of the material. In this case, since the deformation of the flow path forming substrate 10 and the nozzle plate 20 due to heat become substantially the same, it is possible to easily join them using a thermosetting adhesive or the like.

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 21 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 21 need to be formed with a diameter of several tens of μm with high accuracy.

On the other hand, the lower electrode film 6 having a thickness of, for example, about 0.2 to 0.5 μm is formed on the elastic film 50 of the flow path forming substrate 10.
0, a piezoelectric layer 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 described later to form the piezoelectric element 300. I have. 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. In general, 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 of the pressure generating chambers 12. Here, a portion which is constituted by one of the patterned electrodes and the piezoelectric layer 70 and in which a 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 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. Further, here, the piezoelectric element 300 and the elastic film whose displacement is generated 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 60 function as a diaphragm, but the lower electrode film may also serve as the elastic film.

The piezoelectric element 300 of the flow path forming substrate 10
On the side, in the present embodiment, the bonding substrate 30 is formed on the elastic film 50 and the lower electrode film 60 via the sealing member 40.

The bonding substrate 30 is made of a single crystal silicon substrate having a thickness of 150 μm or more.
A predetermined integrated circuit (IC), for example, a drive circuit 31 for driving the piezoelectric element 300 in the present embodiment is integrally formed in a region facing 0. In the present embodiment, the drive circuit 31 is a semiconductor integrated circuit formed integrally with a bonding substrate 30 made of a single crystal silicon substrate by a semiconductor process.

The driving circuit 31 and the piezoelectric element 300
The upper electrode film 80 is electrically connected via a lead electrode 90 provided on the upper electrode film 80. That is, the flow path forming substrate 10 and the bonding substrate 30 are sealed with the sealing member 40.
When joining via the lead electrode 90 and the drive circuit 31
And the upper electrode film 80 and the drive circuit 3
1 are electrically connected via a lead electrode 90.

The bonding substrate 30 and the sealing member 40
Accordingly, in a region opposed to the piezoelectric element 300, a space that does not hinder the movement of the piezoelectric element 300 is secured, and the reservoir 13 is a common ink chamber for the piezoelectric element holding portion 41 and the pressure generating chamber 12 that can seal this space. An ink introduction path 42 for supplying ink to the piezoelectric element 3 is formed.
A connection port 43 for connecting the lower electrode film 60 as a common electrode of 00 and a driving signal line of the driving circuit 31 to an external wiring is defined.

In the present embodiment, for example, as shown in FIG. 3, the driving surface of the bonding substrate 30 on the bonding surface side with the flow path forming substrate 10 is located near the end of the piezoelectric element 300 in the juxtaposition direction. A connection wiring 32 for connecting a circuit 31 and an external wiring 100 such as an FPC is formed. The connection wiring 32 and the external wiring are connected to a connection layer 3 made of an anisotropic conductive material (ACF) or the like.
3 are electrically connected. In addition, connection wiring 3
2 may be formed by extending a wiring at the connection port 43. In this case, the lower electrode film 60 and the signal line for the driving circuit can be mounted collectively, so that the mounting process can be simplified and the head can be downsized.

Here, the manufacturing process of the ink jet recording head of this embodiment will be described. 4 to 6 are cross-sectional views of the pressure generating chamber 12 in the longitudinal direction. 4A to 4C are cross-sectional views of the flow path forming substrate 10, and FIG. 4D is a cross-sectional view of the bonding substrate 30.

First, as shown in FIG. 4A, the flow path forming substrate 1 having a predetermined thickness, in this embodiment, about 220 μm.
The elastic film 50 made of silicon dioxide is obtained by thermally oxidizing a single crystal silicon substrate wafer which becomes zero in a diffusion furnace at about 1100 ° C.
To form

Next, as shown in FIG. 4B, the lower electrode film 60, the piezoelectric layer 70 and the upper electrode film 8 are formed on the elastic film 50.
The piezoelectric elements 300 are formed by sequentially laminating and patterning 0s.

That is, first, the lower electrode film 60 is formed on the elastic film 50 by sputtering. As a material of the lower electrode film 60, platinum or the like is preferable. This is because a piezoelectric layer 70 described later formed by a sputtering method or a sol-gel method is formed.
Is from 600 to 600 ° C. in an air atmosphere or an oxygen atmosphere after film formation.
This is because it is necessary to perform crystallization by firing at a temperature of about 1000 ° C. That is, the material of the lower electrode film 60 must be able to maintain conductivity under such a high temperature and oxidizing atmosphere. In particular, when the piezoelectric layer 70 is made of lead zirconate titanate (PZT), It is desirable that the change in conductivity due to the diffusion of lead oxide is small, and for these reasons, platinum is preferred.

Next, a piezoelectric layer 70 is formed on the lower electrode film 60. For example, in the present embodiment, a so-called sol in which a metal organic material is dissolved and dispersed in a catalyst is applied, dried and gelled,
The piezoelectric layer 70 made of a metal oxide is obtained by firing at a higher temperature, that is, by using a so-called sol-gel method. As a material for the piezoelectric layer 70, a PZT-based material is suitable when used in an ink jet recording head. The method for forming the piezoelectric layer 70 is not particularly limited. For example, the piezoelectric layer 70 may be formed by a spin coating method such as a sputtering method or a MOD method (organic metal thermal coating decomposition method).

Furthermore, a method of forming a precursor film of lead zirconate titanate by a sol-gel method, a sputtering method, a MOD method, or the like, and then growing the crystal at a low temperature by a high-pressure treatment in an alkaline aqueous solution may be used. Good.

In any case, in the piezoelectric layer 70 formed as described above, the crystal is preferentially oriented unlike the bulk piezoelectric, and in the present embodiment, the crystal is formed in the piezoelectric layer 70. It is formed in a column shape. Note that the preferential orientation refers to a state in which a crystal orientation direction is not disordered and a specific crystal plane is oriented in a substantially constant direction. In addition, a crystal having a columnar thin film refers to a state in which substantially columnar crystals are gathered in a plane direction with their central axes substantially aligned in the thickness direction to form a thin film. Of course, it may be a thin film formed of preferentially oriented granular crystals. The thickness of the piezoelectric layer manufactured in the thin film process is generally 0.2 to 5 μm.

Further, an upper electrode film 80 is formed on the piezoelectric layer 70. The upper electrode film 80 only needs to be a material having high conductivity, and can use many metals such as aluminum, gold, nickel, and platinum, and a conductive oxide. In this embodiment,
Platinum is formed by sputtering.

Next, the piezoelectric element 300 is patterned by etching only the piezoelectric layer 70 and the upper electrode film 80.

Next, as shown in FIG. 4C, a lead electrode 90 is formed over the entire surface of the flow path forming substrate 10 and the upper electrode film 80 on one end side in the longitudinal direction of each piezoelectric element 300 is formed.
Pattern on top.

Next, as shown in FIG. 4D, the single crystal silicon substrate which becomes the bonding substrate 30 having a predetermined thickness, in this embodiment, about 220 μm, on the bonding surface side with the flow path forming substrate 10. Then, the drive circuit 31 is integrally formed in a region corresponding to the piezoelectric element 300. The method for forming the drive circuit 31 is not particularly limited. For example, the drive circuit 31 may be formed integrally by a semiconductor process.

Next, as shown in FIG. 5A, the piezoelectric element 300 side of the flow path forming substrate 10 and the drive circuit 31 side of the bonding substrate 30 are bonded via the sealing member 40. At this time,
The piezoelectric element holding portion 41 is defined in a region facing the piezoelectric element 300, and an ink introduction path 42 is defined in a region facing the reservoir 13. Further, a connection port 43 is defined outside the ink introduction path 42. In the present embodiment, the sealing member 40 is an adhesive, and a predetermined amount of an adhesive is applied to a predetermined area to form the flow path forming substrate 10 and the bonding substrate 30.
And the piezoelectric element holding portion 41,
An ink introduction path 42 and a connection port 43 are defined.

Further, when the flow path forming substrate 10 and the bonding substrate 30 are bonded, the lead electrode 90 and the driving circuit 3
By contacting the piezoelectric element 1, the upper electrode film 80, which is an individual electrode of each piezoelectric element 300, is electrically connected to the drive circuit 31. At this time, it is preferable that the lead electrode 90 is provided outside a region to be the pressure generating chamber 12. Thereby, it is possible to prevent the deformation of the diaphragm from being hindered by the driving of the piezoelectric element 300.

Next, as shown in FIG. 5B, the flow path forming substrate 10 and the bonding substrate 30 thus bonded are processed to a predetermined thickness. Specifically, the surfaces of the flow path forming substrate 10 and the bonding substrate 30 are processed to a predetermined thickness by polishing or etching. In the present embodiment, as described above, the flow path forming substrate 10 has a thickness of 50 μm to 150 μm, and the bonding substrate 30 has a thickness of about 150 μm.

Next, as shown in FIG. 5C, mask layers 55A and 55B made of silicon dioxide are formed on the respective surfaces of the flow path forming substrate 10 and the bonding substrate 30 in predetermined regions by sputtering or CVD. To form a film.

Next, as shown in FIG. 6A, the pressure generating chamber 12, the reservoir 13, and the ink supply path 14 are formed by etching the flow path forming substrate 10 through the mask layer 55A. At the same time, by etching the bonding substrate 30 via the mask layer 55B, the ink introduction path 42 is opened and the connection port 43 is opened. Further, the elastic film 5 in a region corresponding to the reservoir 13
The ink communication hole 51 that connects the reservoir 13 and the ink introduction path 42 is formed by removing the 0 and lower electrode films 60.

Thereafter, as shown in FIG. 6B, a nozzle plate having a nozzle opening 21 formed on the opening side of the flow path forming substrate 10 is joined.

A large number of chips are simultaneously formed on one wafer by a series of film formation and anisotropic etching described above, and after the process is completed, a flow path of one chip size as shown in FIG. The ink jet recording head is divided for each forming substrate 10.

The ink jet recording head of the present embodiment manufactured as described above takes in ink from the external ink supply means (not shown) into the reservoir 13 via the ink introduction path 42, and supplies ink from the reservoir 13 to the nozzle opening 21. Is filled with ink, and the lower electrode film 60 and the upper electrode film 8 corresponding to the pressure generating chambers 12 are formed according to the recording signal output from the external wiring 100 via the drive circuit 31.
By applying a voltage between 0 and 0 to bend and deform the elastic film 50, the lower electrode film 60, and the piezoelectric layer 70, the pressure in each pressure generating chamber 12 increases, and ink droplets are ejected from the nozzle openings 21.

In the ink jet recording head having such a configuration, the flow path forming substrate 1 on which the piezoelectric element 300 is formed
0 and the bonding substrate 30 in which the drive circuit 31 is integrally formed in a region facing the piezoelectric element 300, so that the thicknesses of the flow path forming substrate 10 and the bonding substrate 30 can be reduced. The size of the head can be reduced, and the plurality of pressure generating chambers 12 can be arranged at a high density. In addition, the rigidity of the partition walls 11 that partition the pressure generating chambers 12 can be increased, and the compliance of the partition walls 11 can be reduced, thereby improving the ink ejection characteristics.

Since the flow path forming substrate 10 and the bonding substrate 30 are each processed to be thin after bonding, the handling is easy even for a large-sized wafer. Therefore, the number of chips per wafer can be increased, and the manufacturing cost can be reduced. Further, since the chip size can be increased, a long head can be manufactured.

In this embodiment, the upper electrode film 80 of the piezoelectric element 300 and the drive circuit 31 are electrically connected via the lead electrode 90. However, the present invention is not limited to this.
For example, as shown in FIG. 7, a wiring 110 such as a bonding wire having one end connected to the upper electrode film 80 and the other end fixed on the flow path forming substrate 10 is provided.
Joins the flow path forming substrate 10 and the joining substrate 30 so as to press a part of the curved wiring 110, so that the upper electrode film 80 and the driving circuit 31 are connected via the wiring 110. You may make it electrically connect. Note that the other end of the wiring 110 needs to be fixed so as not to be electrically connected to the lower electrode film 60.
Is removed, and the other end of the wiring 110 is fixed to the removed portion. However, the fixing method is not particularly limited as long as it is not electrically connected to the lower electrode film 60.

In this embodiment, an adhesive is used as the sealing member 40. However, the present invention is not limited to this. For example, silicon oxide (SiO ₂ ) or glass may be used. In this case, the flow path forming substrate and the bonding substrate can be bonded by anodic bonding via the sealing member. For example, as shown in FIG. 8, when the sealing member 40A made of glass is used,
By heating to about 0 ° C. and applying a potential of about 200 to 1000 V between each of the flow path forming substrate 10 and the bonding substrate 30 made of single crystal silicon and the sealing member 40, that is, anodic bonding is performed. Thereby, each of the flow path forming substrate 10 and the bonding substrate 30 and the sealing member 40 are chemically bonded. In this case, the lower electrode film 60 and the elastic film 50 need to be removed from the region of the flow path forming substrate 10 where the sealing member 40 is bonded.

When a sealing member made of silicon oxide is used, sputtering or CV is applied to a predetermined region of each of the joint surfaces of the flow path forming substrate 10 and the joining substrate 30.
A sealing member is provided by a method D or the like. Then, the sealing members are brought into contact with each other, and a potential is applied between the flow path forming substrate 10 and the bonding substrate 30 under predetermined conditions to perform anodic bonding under the same conditions as described above, thereby forming the flow path forming substrate 10. And the bonding substrate 30 can be bonded via the sealing member.

(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, as the sealing member, in addition to the above-described example, each layer constituting the piezoelectric element 300 may be constituted by a discontinuous lower electrode film, a piezoelectric layer, and an upper electrode film.

Further, for example, in each of the above-described embodiments, 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 formed by a method such as attaching a green sheet.

The ink jet recording head of each of the embodiments 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 diagram illustrating an example of the ink jet recording apparatus.

As shown in FIG. 9, 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, the apparatus main body 4 is provided with a platen 8 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.

[0080]

As described above, according to the present invention, the flow path forming substrate on which the piezoelectric element is formed and the bonding substrate on which an integrated circuit is integrally formed in a region facing the piezoelectric element are bonded. Therefore, the thickness of the flow path forming substrate and the joining substrate can be reduced, the size of the head can be reduced, and a plurality of pressure generating chambers can be arranged at high density. Further, the rigidity of the partition can be increased and the compliance of the partition can be reduced, so that the ink ejection characteristics can be improved.

[Brief description of the drawings]

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

FIG. 4 is a cross-sectional view illustrating a manufacturing process of the ink jet recording head according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a manufacturing process of the ink jet recording head according to Embodiment 1 of the present invention.

FIG. 6 is a cross-sectional view illustrating a manufacturing process of the ink jet recording head according to Embodiment 1 of the present invention.

FIG. 7 is a cross-sectional view showing a modification of the ink jet recording head according to the first embodiment of the present invention.

FIG. 8 is a sectional view showing a modification of the ink jet recording head according to the first embodiment of the present invention.

FIG. 9 is a schematic view 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 11 partition wall 12 pressure generating chamber 13 reservoir 14 ink supply path 20 nozzle plate 21 nozzle opening 30 bonding substrate 31 drive circuit 40 sealing member 50 elastic film 60 lower electrode film 70 piezoelectric layer 80 upper electrode film 300 piezoelectric element

Claims (13)

[Claims] 1. A flow path forming substrate made of single crystal silicon in which a pressure generating chamber communicating with a nozzle opening is defined, a lower electrode provided on one side of the flow path forming substrate via a diaphragm, and a piezoelectric element. An ink jet recording head comprising a body element and a piezoelectric element comprising an upper electrode, comprising: a bonding substrate made of single crystal silicon bonded to the piezoelectric element side of the flow path forming substrate via a sealing member; An ink jet recording head, wherein an integrated circuit is integrally formed in a region of the bonding substrate facing the piezoelectric element on a bonding surface side with the flow path forming substrate. 2. The device according to claim 1, wherein a conductive member is connected to one of the lower electrode and the upper electrode constituting the piezoelectric element, and the conductive member contacts a connection wiring of the integrated circuit. Wherein the piezoelectric element and the integrated circuit are electrically connected to each other. 3. The ink jet recording head according to claim 1, wherein the piezoelectric element is sealed in a space defined by the bonding substrate and the sealing member. 4. The ink jet recording head according to claim 1, wherein the sealing member is an adhesive. 5. The sealing member according to claim 1, wherein the sealing member is made of silicon oxide or glass, and the flow path forming substrate and the bonding substrate are bonded by anodic bonding via the sealing member. An ink jet recording head characterized in that: 6. The method according to claim 2, wherein the conductive member is a bonding wire having one end connected to the upper electrode and the other end fixed to the flow path forming substrate. Inkjet recording head. 7. The pressure generating chamber according to claim 1, wherein the pressure generating chamber is formed by anisotropic etching, and the respective layers constituting the diaphragm and the piezoelectric element are formed by film formation and lithography. An ink jet recording head, characterized in that: 8. An ink jet recording apparatus comprising the ink jet recording head according to claim 1. 9. A flow path forming substrate formed of single crystal silicon and defining a pressure generating chamber communicating with a nozzle opening, a lower electrode provided on one side of the flow path forming substrate via a diaphragm, and a piezoelectric element. A method for manufacturing an ink jet recording head, comprising: a piezoelectric element comprising a body layer and an upper electrode; and a bonding substrate made of single crystal silicon bonded to the piezoelectric element side of the flow path forming substrate, wherein the flow path forming substrate The lower electrode through the diaphragm above,
Laminating and patterning the piezoelectric layer and the upper electrode to form the piezoelectric element, and integrally forming an integrated circuit in a region of the one surface of the bonding substrate facing the piezoelectric element, Bonding the piezoelectric element side of the flow path forming substrate and the integrated circuit side of the bonding substrate via a sealing member, and processing the flow path forming substrate and the bonding substrate to a predetermined thickness; Forming the pressure generating chamber. 10. The pressure generating chamber according to claim 9, wherein, in the step of forming the pressure generating chamber, the pressure generating chamber is formed by etching the flow path forming substrate and the pressure generating chamber is etched by etching the bonding substrate. A method for manufacturing an ink jet recording head, comprising forming a flow path for supplying ink to a chamber. 11. The flow path forming substrate according to claim 9, wherein a conductive member having conductivity and one end of which is connected to one of the lower electrode and the upper electrode constituting the piezoelectric element is provided. An ink jet recording method for electrically connecting the piezoelectric element and the integrated circuit by bringing the conductive member into contact with the connection wiring of the integrated circuit when bonding the substrate and the bonding substrate. Head manufacturing method. 12. The piezoelectric element according to claim 11, wherein, in the step of forming the pressure generating chamber, the pressure generating chamber is formed by etching the flow path forming substrate and the bonding substrate is etched. Forming a connection port for connecting the other electrode and the external wiring constituting the ink jet recording head. 13. The sealing member according to claim 9, wherein the sealing member is glass or a silicon oxide layer provided on a bonding surface side of each of the flow path forming substrate and the bonding substrate. A method of manufacturing an ink jet type recording head, wherein the flow path forming substrate and the bonding substrate are bonded by anodic bonding via a stopper member.