JP2001096744A - Ink-jet recording head, its manufacturing method and ink-jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink-jet recording head which can be formed highly accurately and simplified in manufacture process, and its manufacturing method and an ink-jet recording apparatus. SOLUTION: The ink-jet recording head has pressure generation chambers 11 communicating with nozzle openings and piezoelectric elements 300 each comprised of a lower electrode 60, a piezoelectric layer 70 and an upper electrode 80 set via an insulating layer 50 in a region corresponding to the pressure generation chamber 11. A channel form layer 12 for forming a peripheral wall of the pressure generation chamber 11 is set on a substrate 13. Moreover, the piezoelectric element 300 is formed on the channel form layer 12 via the insulating layer 50. Each layer of the channel form layer 12, the insulating layer 50 and the piezoelectric element 300 is formed of a thin film by a film forming and lithography method without interposing an adhesive layer. Therefore, the pressure generation chambers 11 and the piezoelectric elements 300 can be highly accurately and highly densely formed.

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 a 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 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 such an ink jet type recording head, since the pressure generating chamber penetrates in the thickness direction by, for example, etching from the surface of the substrate opposite to the piezoelectric element, the dimensional accuracy is reduced. High pressure generating chambers can be relatively easily and densely arranged.

[0008]

However, such an ink jet recording head has a problem in that the number of parts is large, the assembling process is complicated, the manufacturing efficiency is low, and the cost is high. Although high positional accuracy is required for assembling these components, there is also a problem that since many components are joined via an adhesive layer, the positional accuracy is low and the yield is poor.

In view of such circumstances, an object of the present invention is to provide an ink jet recording head, a method of manufacturing the same, and an ink jet recording apparatus which can be formed with high precision and can simplify the manufacturing process.

[0010]

According to a first aspect of the present invention, there is provided a pressure generating chamber communicating with a nozzle opening, and a pressure generating chamber provided in a region corresponding to the pressure generating chamber via an insulating layer. In the ink jet recording head having a lower electrode, a piezoelectric layer, and a piezoelectric element including an upper electrode, a flow path forming layer that forms a peripheral wall of the pressure generating chamber is provided on a substrate, and the flow path forming layer The piezoelectric element is formed through the insulating layer, and each of the flow path forming layer, the insulating layer and the piezoelectric element is formed by a thin film formed by film formation and lithography without an adhesive layer. An ink jet recording head is characterized in that:

In the first aspect, the pressure generating chamber is formed by the flow path forming layer provided on the substrate, and each of the flow path forming layer, the insulating layer, and the piezoelectric element is formed by a thin film. Therefore, the pressure generating chamber and the piezoelectric element can be formed with high precision and high density.

According to a second aspect of the present invention, there is provided the ink jet recording head according to the first aspect, wherein the piezoelectric layer has crystals oriented preferentially.

In the second aspect, as a result of forming the piezoelectric layer in the thin film process, the crystals are preferentially oriented.

According to a third aspect of the present invention, there is provided an ink jet recording head according to the second aspect, wherein the piezoelectric layer has a columnar crystal.

In the third aspect, as a result of the piezoelectric layer being formed in the thin film process, the crystal has a columnar shape.

According to a fourth aspect of the present invention, in any one of the first to third aspects, each layer constituting the piezoelectric element is provided on the sacrificial layer which is provided in the pressure generating chamber and finally removed. An ink jet recording head characterized in that it is a formed thin film.

In the fourth aspect, the sacrifice layer is filled in the pressure generating chamber, so that the piezoelectric element can be easily formed in a region facing the pressure generating chamber by a thin film process.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the flow path forming layer and the piezoelectric element
An ink jet recording head is formed on both surfaces of the substrate.

In the fifth aspect, the rows of nozzle openings are provided on both sides of the substrate, so that the rows of nozzle openings can be arranged at a high density.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the flow path forming layer forms a reservoir communicating with each pressure generating chamber together with the pressure generating chamber. The feature is the ink jet recording head.

In the sixth aspect, since the reservoir can be formed with high precision and is formed in the same layer as the pressure generating chamber, the size of the head can be reduced.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the nozzle opening is formed to penetrate the piezoelectric element in a region facing the pressure generating chamber. And an ink jet recording head.

In the seventh aspect, a nozzle opening for discharging ink droplets in a direction substantially perpendicular to the substrate is formed.

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 head in which pressure generating chambers and piezoelectric elements are arranged with high precision and high density.

A ninth aspect of the present invention comprises a pressure generating chamber communicating with a nozzle opening, and a lower electrode, a piezoelectric layer and an upper electrode provided in a region corresponding to the pressure generating chamber via an insulating layer. A piezoelectric element, wherein the pressure generating chamber is formed in a flow path forming layer provided on a substrate, and the piezoelectric element is formed on the flow path forming layer. Forming the pressure forming chamber by forming and patterning the flow path forming layer on a substrate, filling the pressure generating chamber with a sacrificial layer, and forming the insulating layer on the flow path forming layer And a step of forming the piezoelectric element in a region facing the pressure generating chamber and a step of removing the sacrificial layer filled in the pressure generating chamber. is there.

According to the ninth aspect, the pressure generating chamber and the piezoelectric element can be formed relatively easily with high precision and high density.

According to a tenth aspect of the present invention, in the ninth aspect, the flow path forming layer, the insulating layer, and the respective layers constituting the piezoelectric element are formed as thin films by film formation and lithography. To manufacture an ink jet recording head.

In the tenth aspect, since the respective layers of the flow path forming layer, the insulating layer, and the piezoelectric element can be formed without the interposition of the adhesive layer, they can be formed more reliably with high precision and high density.

According to an eleventh aspect of the present invention, in the ninth or tenth aspect, in the step of forming the piezoelectric element, the piezoelectric element is provided on the piezoelectric element in a region facing the pressure generating chamber in the thickness direction. And forming the nozzle opening by penetrating the ink jet recording head.

In the eleventh aspect, a nozzle opening for ejecting ink droplets in a substantially vertical direction can be easily formed on the substrate.

[0032]

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 cross-sectional structure in a longitudinal direction of a pressure generating chamber of the ink jet recording head. FIG.

As shown in the drawing, in the ink jet type recording head 10 of this embodiment, the flow path forming layer 12 in which the ink flow path such as the pressure generating chamber 11 is formed has a thickness of, for example, 0.5 to 0.5 mm. It is formed on a base substrate 13 made of a 6 mm silicon single crystal substrate. In the present embodiment, the flow path forming layers 12 are provided on both surfaces of the base substrate 13, respectively.

The flow path forming layer 12 provided on the base substrate 13 is made of, for example, silicon nitride (SiN) having a thickness of 50 to 100 μm. The row of the pressure generating chambers 11 partitioned by the plurality of partition walls is formed by etching.
Further, a nozzle opening 14 for discharging ink in communication with each pressure generating chamber 11 is formed in the flow path forming layer 12 on one end side in the longitudinal direction of the pressure generating chamber 11, and each nozzle opening 14 is formed on the other end side. A reservoir 15 serving as a common ink chamber for the pressure generating chamber 11 is formed and communicates with the pressure generating chamber 11 via a communication path 16.

On the opposite side of the communication path 16 of the reservoir 15, an ink supply means such as an ink cartridge is connected to an ink supply path of a fixed plate which will be described later.
An ink introduction path 17 for supplying ink to the ink supply path is formed. In the present embodiment, the ink introduction path 17 also
It is formed by etching the channel forming layer 12 in the same manner as the pressure generating chamber 11 and the like.

Here, the pressure generating chamber 11 and the reservoir 15
Is formed by etching substantially through the flow path forming layer 12. On the other hand, the nozzle opening 14 and the communication path 16 are formed shallower than the pressure generating chamber 11 by etching (half etching) partway in the thickness direction. Note that the half etching is performed by adjusting the etching time.

The size of the pressure generating chamber 11 for applying the ink droplet ejection pressure to the ink and the size of the nozzle opening 14 for ejecting the ink droplet are optimal according to the amount of the ejected ink droplet, the ejection speed, and the ejection frequency. Be transformed into For example, 1
When recording 360 ink droplets per inch, the nozzle openings 14 need to be formed with a groove width of several tens μm with high accuracy.

On the flow path forming layer 12 in which the pressure generating chambers 11 and the like are formed, for example, a silicon nitride (SiN) or zirconium oxide (ZrO ₂ ) having a thickness of 0.1 mm is used.
An elastic film 50 having a thickness of 3 to 0.6 μm is provided. The elastic film 50 forms one wall surface of the pressure generating chamber 11 on one surface.

In a region on the elastic film 50 facing each pressure generating chamber 11, the thickness is, for example, about 0.1 to 0.1.
The lower electrode film 60 having a thickness of about 0.5 μm
And a thickness of about 0.1 to 3 μm, for example.
The upper electrode film 80 having a thickness of 0.2 μm is formed by lamination in a process described later to form the piezoelectric element 300. 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 of the pressure generating chambers 11. 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 the piezoelectric element 30.
Although the number of the individual electrodes is 0, there is no problem even if this is reversed for convenience of the drive circuit and wiring. In any case, the piezoelectric active portion is formed for each pressure generating chamber. Also, here, the piezoelectric element 300 and the piezoelectric element 3
The elastic film that is displaced by the driving of 00 is collectively referred to as a piezoelectric actuator.

The lower electrode film 60, which is a common electrode of each piezoelectric element 300, is provided continuously in a region corresponding to the pressure generating chambers 11 arranged in parallel, and functions as a diaphragm together with the elastic film 50. . Of course, the lower electrode film may also serve as the elastic film. On the other hand, a connection wiring 110 such as a flexible printed circuit (FPC) is connected to one end of the upper electrode film 80 as an individual electrode of each piezoelectric element 300 via an adhesive layer 100 made of ACF or the like.

On the surface of such a piezoelectric element 300, for example, a protective film 90 made of silicon nitride or the like having a thickness of 0.1 to 0.3 μm is formed. The destruction of 300 is prevented.

Here, the pressure generating chamber 11 is formed in the flow path forming layer 12.
A process for forming the piezoelectric element 300 in a region corresponding to the pressure generating chamber 11 will be described with reference to FIGS. 3 and 4 are cross-sectional views in the longitudinal direction of the pressure generating chamber.

First, as shown in FIG. 3A, a flow path forming layer 12 is formed and patterned on both surfaces of a wafer of a base substrate 13 composed of a silicon single crystal substrate, and the pressure generating chamber 11 and the nozzle are formed. The opening 14, the reservoir 15, the communication path 16, and the ink introduction path 17 are formed simultaneously.

Here, the pressure generating chamber 11 and the reservoir 15
Is formed by etching until it substantially penetrates the flow path forming layer 12, and a part of the flow path forming layer 12 is formed on the surface of the base substrate 13, for example, with a thickness of about It is preferable to provide the remaining portion 12a that has been left. Note that the remaining portion 12a is formed by a sacrificial layer 20 described later.
Plays a role in stopping the etching when removing.

In this embodiment, a silicon single crystal substrate is used as the base substrate 13 on which the flow path forming layer 12 is formed. However, the present invention is not limited to this, and the flatness and the adhesion to the thin film are good. And any material having heat resistance that can withstand firing of the piezoelectric layer described below, for example,
An inorganic material such as glass or a metal plate may be used.

Next, as shown in FIG. 3B, a sacrifice layer 20 is filled in a portion that becomes an ink flow path, such as the pressure generating chamber 11. In the present embodiment, after forming the sacrificial layer 20 over the entire surface of the flow path forming layer 12, the sacrificial layer 20 other than the ink flow path such as the pressure generating chamber 11 is removed and flattened by chemical mechanical polishing (CMP). It has become.

Although the material of the sacrificial layer 20 is not particularly limited, for example, polysilicon or phosphorus-doped silicon oxide (PSG) may be used. In this embodiment, PSG having a relatively high etching rate is used. .

The method of forming the sacrificial layer 20 is not particularly limited. For example, ultra-fine particles of 1 μm or less are converted into helium (He).
For example, a method called a gas deposition method or a jet molding method in which a film is formed by colliding with a substrate at a high speed by the pressure of a gas such as that described above may be used.
According to this method, the sacrifice layer 20 can be partially formed only in a region corresponding to the pressure generating chamber 11 or the like.

Next, as shown in FIG. 3C, an elastic film 50 is formed on the flow path forming layer 12 and the sacrificial layer 20, and a lower electrode film constituting a piezoelectric element is formed on the elastic film 50. 6
0, a piezoelectric layer 70 and an upper electrode film 80 are sequentially laminated.

Here, the elastic film 50 is made of, for example, zirconium oxide (ZrO ₂ ). In this embodiment, after the zirconium layer is formed on the flow path forming layer 12, for example,
The elastic film 50 made of zirconium oxide was thermally oxidized in a diffusion furnace at 0 to 1200 ° C. The material of the elastic film 50 is not particularly limited as long as the material is not etched when the sacrificial layer 20 is removed.
iN).

As a material of the lower electrode film 60, iridium, platinum, or the like is preferable. This is because a piezoelectric layer 70 described later, which is formed by a sputtering method or a sol-gel method,
After film formation, 600 to 10 in an air atmosphere or an oxygen atmosphere
This is because it is necessary to perform crystallization by firing at a temperature of about 00 ° 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, iridium or platinum is preferable.

The crystal of the piezoelectric layer 70 is preferably oriented. Examples of the material include a lead zirconate titanate (PZT) -based material and barium titanate (BT).
O), a mixed crystal of barium titanate and strontium titanate [(Ba, Sr) TiO ₃ (BST)] and the like are preferable. In the present embodiment, a PZT-based material is used, a so-called sol in which a metal organic substance is dissolved and dispersed in a catalyst is applied, dried and gelled, and further fired at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide. , Using a so-called sol-gel method. The method for forming the piezoelectric layer 70 is as follows.
There is no particular limitation, for example, sputtering method or MOD
The film may be formed by a spin coating method such as a method (organic metal thermal coating decomposition method).

Further, 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 in this manner, crystals are preferentially oriented differently from bulk piezoelectrics, and in the present embodiment, the piezoelectric layer 70 is composed of crystals. 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.

As a material of the upper electrode film 80, for example, a metal such as iridium and platinum and an oxide thereof, which have high conductivity and hardly cause electromigration, are preferable. In this embodiment, the upper electrode film 80 is formed by depositing iridium by a sputtering method.

Next, as shown in FIG. 3D, the lower electrode film 60, the piezoelectric layer 70 and the upper electrode film 80 are patterned to form the piezoelectric element 300, and the elastic film 50 is formed into a predetermined shape. Perform patterning. In the present embodiment, the piezoelectric element 300 is formed in a region facing the communication passage 16 from the nozzle opening 14.

Next, as shown in FIG. 3E, a protective film 90 is formed to cover the surface of the piezoelectric element 300. At this time, an exposed portion 80a whose surface is exposed is formed in a region facing the communication passage 16 at one longitudinal end of the upper electrode film 80.

The protective film 90 prevents the piezoelectric element 300 from being destroyed due to the attachment of ink droplets and the like.
The material is not particularly limited as long as the material can protect the piezoelectric element 300 from ink droplets. For example, in this embodiment, silicon nitride is used. Also, this protective film 90
The piezoelectric element 300 is preferably formed to be relatively thin so as not to hinder the driving of the piezoelectric element 300, for example, to have a thickness of about 0.1 to 0.3 μm.

Thereafter, as shown in FIG. 4A, the sacrificial layer 20 is removed from the nozzle opening 14 and the ink introduction path 17 by, for example, wet etching.
An ink flow path such as the pressure generating chamber 11 is formed. At this time, the remaining portion 1 of the flow path forming layer 12 is formed on the base substrate 13.
Since 2a is present, etching is stopped by the remaining portion 12a. In the present embodiment, since the sacrificial layer 20 is made of PSG, the sacrificial layer 20 is etched with a hydrofluoric acid aqueous solution. When polysilicon is used, etching can be performed with a mixed aqueous solution of hydrofluoric acid and nitric acid or an aqueous solution of potassium hydroxide. The method of removing the sacrificial layer 20 is not limited to wet etching, but may be, for example, etching with hydrofluoric acid vapor.

The above is the film forming process. By such a series of film forming processes, piezoelectric elements and the like are formed on a single wafer at the same time by forming a large number of chips.
It is divided into one chip size by dicing or the like.

Thereafter, as shown in FIG. 4B, one end of the connection wiring 110 is connected to the exposed portion 80a of the upper electrode film 80 via the adhesive layer 100. At this time, the other end of the connection wiring 110 is bent at a substantially right angle to the side opposite to the base substrate 13. This facilitates connection with the drive circuit 34 described later.

In the ink jet recording head thus formed, a fixing member 30 is bonded and fixed to the base substrate 13 and the channel forming layer 12 on the side of the reservoir 15, as shown in FIGS. FIG. 5 is a sectional view showing an assembly state of the head and the fixing member, and FIG.
It is a side view on the nozzle opening side and the fixing member side.

As shown in the figure, the fixing member 30 has an ink supply path 31 communicating with ink supply means such as an ink cartridge. An ink supply needle 32 connected to the ink cartridge or the like is provided at one end. It is fixed across the filter 33. Further, the other end of the ink supply path 31 of the fixing member 30 is branched into two, and is connected to the reservoirs 15 provided on both sides of the base substrate 13, respectively. Further, a circuit board 35 to which a drive circuit 34 such as a drive IC for driving the piezoelectric elements 300 is fixed is fixed to the fixing member 30 corresponding to the rows of the piezoelectric elements 300 on both sides of the base substrate 13. ing.

The fixing member 30 and the ink supply needle 3
2 and the circuit board 35 are assembled in a pre-assembled assembly 40.
As a result, the positioning is facilitated. Further, as described above, the connection wiring 110 connected to the upper electrode film 80 of each piezoelectric element 300 can be easily and electrically connected to the drive circuit 34 by, for example, thermocompression bonding, thereby simplifying the manufacturing process. be able to. Therefore, the rows of the nozzle openings 14 can be easily formed on both sides of the base substrate 13. That is, the rows of nozzle openings can be arranged at a high density, and the head can be downsized.

In the ink jet recording head of this embodiment, ink is taken into the head via an ink supply needle 32 and an ink supply path 31 connected to an external ink supply means (not shown), and the ink is supplied from the reservoir 15 to the nozzle opening 14. After filling the inside with ink up to
4, a voltage is applied between the lower electrode film 60 and the upper electrode film 80 corresponding to each pressure generating chamber 11 to deflect the elastic film 50, the lower electrode film 60, and the piezoelectric layer 70. By the deformation, the pressure in each pressure generating chamber 11 increases, and ink droplets are ejected from the nozzle openings 14.

As described above, in the configuration of the present embodiment, each layer of the flow path forming layer 12 in which the pressure generating chamber 11 is formed, the elastic film 50 and the piezoelectric element 300 is formed by so-called surface micromachining using the sacrifice layer 20. It is formed without the interposition of the adhesive layer by the technique described above. Accordingly, the piezoelectric element 300 and the like can be formed with high precision and high density, and the head can be relatively easily reduced in size. Also,
Since the head assembling process is simplified, the yield can be improved and the manufacturing cost can be reduced.

Further, since it is not necessary to etch the single crystal silicon substrate, a head having a free shape can be manufactured without being affected by the orientation of the crystal orientation plane. Further, since there is no influence of the crystal orientation plane, the chips can be relatively freely arranged on the wafer, so that the number of chips per wafer can be increased and the manufacturing cost can be reduced.

(Embodiment 2) FIG. 7 is a sectional view of an essential part of an ink jet recording head according to Embodiment 2. 7A is a cross-sectional view of the pressure generating chamber in the longitudinal direction, and FIG. 7B is a cross-sectional view of the nozzle opening in FIG. 7A in the width direction of the pressure generating chamber.

In this embodiment, as shown in FIG. 7, the flow path forming layer 12 in which the pressure generating chamber 11 is formed is provided only on one side of the base substrate 13, and the flow path forming layer 12 For example, the piezoelectric element 300 is formed via the insulating layer 120 made of silicon nitride or the like and the elastic film 50A. Further, a protective film 90 is formed on the upper electrode film 80 of the piezoelectric element 300.

In this embodiment, the nozzle opening 14A
Is formed by penetrating the piezoelectric element 300 in the thickness direction in a region facing the vicinity of the end of the pressure generating chamber 11 opposite to the reservoir 15 instead of being formed in the flow path forming layer 12. . In addition, a protective film 90 is formed on the inner surface of the nozzle opening 14A continuously from the surface of the piezoelectric element 300, thereby preventing the piezoelectric element 300 from being broken due to the attachment of ink droplets.

As described above, by providing a through hole in the piezoelectric element 300 and using the through hole as the nozzle opening 14A,
There is no need to separately provide a nozzle plate, and a nozzle opening can be easily formed.

The position where the nozzle opening 14A is formed may be any position as long as the piezoelectric element 300 is located in a region facing the pressure generating chamber 11, but when a voltage is applied to the piezoelectric element 300, it is relatively deformed. It is preferable to be in the vicinity of the end in the longitudinal direction where there is little difference.

In the ink jet recording head having the configuration of the present embodiment, when a voltage is applied to the piezoelectric element 300, the piezoelectric element 300 is deformed in a direction in which the volume of the pressure generating chamber 11 is increased, and the application of the voltage is released. As a result, the deformation of the piezoelectric element 300 is released, and ink droplets are ejected from the nozzle opening 14A.

The method of manufacturing the ink jet recording head having such a configuration is not particularly limited, but it can be formed as follows.

The method of manufacturing the ink jet recording head of this embodiment is basically the same as that of the first embodiment. First, as in the steps shown in FIGS. The pressure generating chamber 11, the reservoir 15, and the communication path 1
6 and the ink introduction path 17 are formed, and the sacrifice layer 20 is filled in the ink flow paths such as the pressure generating chambers 11 and the like.

Next, as shown in FIG. 8A, an insulating layer 120 serving as a part of the pressure generating chamber 11 is formed on the flow path forming layer 12.
Is formed on the entire surface, and an elastic film 50A serving as a diaphragm is formed on the insulating layer 120. Further, a lower electrode film 60, a piezoelectric layer 70, and an upper electrode film 80 are sequentially formed.

Here, the material of the insulating layer 120 is not particularly limited as long as the material can protect the piezoelectric element 300 from the ink droplets in the pressure generating chamber 11, but for example, in the present embodiment, the thickness is 0.1-0.2 μm silicon nitride (S
iN).

Next, as shown in FIG. 8B, the upper electrode film 80, the piezoelectric layer 70, the lower electrode film 60, and the elastic film 50A are patterned to form the piezoelectric element 300, and each of these layers and Nozzle opening 14 penetrating insulating layer 120
Form A.

Next, as shown in FIG. 8C, a protective film 90 is formed along with the shape of the piezoelectric element 300 and is patterned to form the surface of the piezoelectric element 300 and the nozzle opening 1.
A protective film 90 is formed on the inner surface of 4A. In the region facing the peripheral wall of the pressure generating chamber 11, as in the first embodiment,
An exposed portion 80a for connecting the connection wiring 110 is formed by exposing a part of the surface of the upper electrode film 80.

The following steps are the same as in the first embodiment.
After the sacrificial layer 20 is removed, the chip is cut into each chip size, and then the connection wiring 110 is connected to the exposed portion 80a of the upper electrode film 80.

The ink jet recording head thus formed is then provided with a fixing member 3 as shown in FIG.
OA is adhesively fixed.

The fixing member 30A of this embodiment has a substantially L-shaped cross section, and is bonded to the surface of the base substrate 13 opposite to the flow path forming layer 12 and the end surface of the piezoelectric element 300 on the reservoir 15 side. It is adhesively fixed with an agent or the like. Further, the fixing member 30A of the present embodiment has an ink supply path 31 on the lower surface near the end of the base substrate 13 on the side of the reservoir 15 and the ink supply needle 32 is fixed, so that the end surface of the base substrate 13 is fixed to the fixing member 30A. An ink supply path 31 </ b> A communicating with the reservoir 15 is defined between them.

The ink supply path 3 of the fixing member 30A
A circuit board 35 having a drive circuit 34 is fixed to the end opposite to the end 31A, and the upper electrode film 80 and the drive circuit 34 are electrically connected via the connection wiring 110. .

The fixing member 30A, the ink supply needle 32, and the circuit board 35 are bonded and fixed to the head 10 as an assembly 40A as in the first embodiment.

With such a configuration, as in the first embodiment, the piezoelectric element 300 and the like can be formed with high accuracy and high density, and the size of the head can be relatively easily reduced. Further, since the head assembling process is simplified, the yield can be improved and the manufacturing cost can be reduced.

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

For example, the fixing member 30 and its assembly 40
Is not particularly limited, and may be any structure.

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. 1 is a schematic view showing an example of the ink jet recording apparatus.

As shown in FIG. 10, recording head units 1A and 1B having an ink jet recording head are
Cartridges 2A and 2B constituting ink supply means are detachably provided. A carriage 3 on which the recording head units 1A and 1B are mounted is provided on a carriage shaft 5 attached to the apparatus main body 4 so as to be movable in the axial direction. I have. 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.

[0092]

As described above, according to the present invention, each layer of the flow path forming layer in which the pressure generating chamber is formed, the insulating layer, and the piezoelectric element is formed by a so-called surface micromachining technique without using an adhesive layer. Therefore, the piezoelectric element and the like can be formed with high precision and high density, and the size of the head can be relatively easily reduced.
Further, since it is not necessary to etch the single crystal silicon substrate, there is an effect that a head having a free shape can be manufactured without being affected by the orientation of the crystal orientation plane.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of a main part of the inkjet recording head according to the first embodiment of the invention.

FIG. 3 is a sectional view illustrating a manufacturing process of the ink jet recording head according to the first embodiment of the 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 an assembly state of the inkjet recording head and the fixing member according to the first embodiment of the present invention.

FIG. 6 is a side view showing an assembly state of the inkjet recording head and the fixing member according to the first embodiment of the present invention.

FIG. 7 is a sectional view of a main part of an ink jet recording head according to a second embodiment of the invention.

FIG. 8 is a cross-sectional view illustrating a manufacturing process of the ink jet recording head according to Embodiment 2 of the present invention.

FIG. 9 is a sectional view showing an assembly state of an ink jet recording head and a fixing member according to a second embodiment of the present invention.

FIG. 10 is a sectional view of an ink jet recording apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 11 pressure generating chamber 12 flow path forming layer 13 base substrate 14 nozzle opening 15 reservoir 16 communication path 17 ink introduction path 60 lower electrode film 70 piezoelectric layer 80 upper electrode film 300 piezoelectric element

Claims (11)

[Claims] 1. An ink jet type comprising: a pressure generating chamber communicating with a nozzle opening; and a piezoelectric element including a lower electrode, a piezoelectric layer, and an upper electrode provided in a region corresponding to the pressure generating chamber via an insulating layer. In the recording head, a flow path forming layer forming a peripheral wall of the pressure generation chamber is provided on a substrate, and the piezoelectric element is formed on the flow path forming layer via the insulating layer, and the flow path forming layer An ink-jet recording head, wherein each of the insulating layer and each layer of the piezoelectric element is formed by a thin film formed by film formation and lithography without using an adhesive layer. 2. The ink jet recording head according to claim 1, wherein crystals of the piezoelectric layer are preferentially oriented. 3. The ink-jet recording head according to claim 2, wherein the piezoelectric layer has a columnar crystal. 4. The method according to claim 1, wherein each of the layers constituting the piezoelectric element is a thin film formed on a sacrificial layer provided in the pressure generating chamber and finally removed. Characteristic inkjet recording head. 5. The ink jet recording head according to claim 1, wherein the flow path forming layer and the piezoelectric element are formed on both surfaces of the substrate. 6. The ink jet recording head according to claim 1, wherein the flow path forming layer forms a reservoir communicating with each pressure generating chamber together with the pressure generating chamber. 7. An ink jet recording head according to claim 1, wherein said nozzle opening is formed through said piezoelectric element in a region facing said pressure generating chamber. 8. An ink jet recording apparatus comprising the ink jet recording head according to claim 1. 9. A pressure generating chamber communicating with a nozzle opening, and a piezoelectric element including a lower electrode, a piezoelectric layer, and an upper electrode provided in a region corresponding to the pressure generating chamber via an insulating layer, A method for manufacturing an ink jet type recording head, wherein the pressure generating chamber is formed in a flow path forming layer provided on a substrate and the piezoelectric element is formed on the flow path forming layer, wherein the flow path forming on the substrate is performed. Forming a layer and patterning to form the pressure generating chamber, filling the pressure generating chamber with a sacrificial layer, and forming the insulating layer on the flow path forming layer and forming the pressure generating chamber in the pressure generating chamber. A method for manufacturing an ink jet recording head, comprising: forming a piezoelectric element in a region opposed to the piezoelectric element; and removing the sacrificial layer filled in the pressure generating chamber. 10. The flow path forming layer according to claim 9, wherein
A method for manufacturing an ink jet recording head, wherein the insulating layer and each layer constituting the piezoelectric element are formed as a thin film by film formation and lithography. 11. The method according to claim 9, wherein in the step of forming the piezoelectric element, the nozzle opening penetrates the piezoelectric element in a region facing the pressure generating chamber in a thickness direction. A method for producing an ink jet recording head, comprising: