JPH1191103A - Ink-jet type recording head, its manufacture, and ink-jet type recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink-jet type recording head and its manufacture whereby the head can be formed with a minimum of patterning, increased in shift amount and discharge speed and lowered in driving voltage. SOLUTION: This ink-jet type recording head has a piezoelectric actuator including a piezoelectric element 300 comprising a lower electrode 60, a piezoelectric body layer 70 and an upper electrode 80. The piezoelectric body layer 70 and upper electrode 80 are formed for every area confronting to a pressure generation chamber 12 not to exceed the area excluding at least a pair of thin arm parts 70a, 80a extending to the outside the area confronting to the pressure generation chamber 12. In the lower electrode 60, an area part confronting to each pressure generation chamber 12 and a wiring pattern part connecting the area parts are continuously formed. Moreover, a part of the lower electrode within the confronting area part where a piezoelectric element 300 is not formed is removed except at least between the pair of thin arm parts 70a and 80a. The confronting area part and the wiring pattern part connecting the area parts continue between the pair of the thin arm parts 70a and 80a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a part of a pressure generating chamber which communicates with a nozzle opening for discharging ink droplets, which is constituted by a vibrating plate. The present invention relates to an ink jet recording head for ejecting ink droplets by displacement, 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. An ink jet recording head for ejecting ink droplets uses a longitudinal vibration mode piezoelectric actuator that expands and contracts in the axial direction of the piezoelectric element, and a flexural vibration mode piezoelectric actuator.
The types have been put to practical use.

In the former method, the volume of the pressure generating chamber can be changed by bringing the end face of the piezoelectric 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 over the entire surface of the diaphragm by a film forming technique 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.

[0006] According to this, the operation of attaching the piezoelectric element to the diaphragm becomes unnecessary, and not only can the piezoelectric element be manufactured by a precise and simple method such as lithography, but also the thickness of the piezoelectric element can be reduced. There is an advantage that it can be made thin and can be driven at high speed. In this case, the piezoelectric actuator corresponding to each pressure generating chamber can be driven by providing at least the upper electrode only for each pressure generating chamber while the piezoelectric material layer is provided on the entire surface of the vibration plate. Due to the problem of the amount of displacement per unit drive voltage and the stress applied to the piezoelectric layer at the part facing the pressure generating chamber and the part that crosses the outside, the piezoelectric active part consisting of the piezoelectric layer and the upper electrode is located outside the pressure generating chamber. It is desirable to form it so that it does not come out.

[0007]

In general, the piezoelectric constant of a piezoelectric thin film is only one-half to one-third that of a thick thin film, so that it is difficult to obtain an effective ink discharge amount. is there.

Therefore, in order to increase the amount of displacement caused by driving the piezoelectric actuator, it is desirable to increase the compliance by reducing the thickness of the lower electrode acting as a vibration plate. There's a problem.

On the other hand, if the lower electrode is patterned while leaving at least a portion corresponding to the piezoelectric active portion, the displacement can be increased while maintaining proper compliance, but the wiring for functioning as a common electrode is not sufficient. In addition, there is a problem that if both are to be realized, the number of patterning steps is increased and the cost is increased.

In view of such circumstances, the present invention provides an ink jet recording head which can be formed with minimum patterning, increases displacement, increases discharge speed and lowers drive voltage, a method of manufacturing the same, and an ink jet recording head. It is an object to provide an expression recording device.

[0011]

According to a first aspect of the present invention for solving the above-mentioned problems, an elastic film forming a part of a pressure generating chamber communicating with a nozzle opening and a region corresponding to the pressure generating chamber are provided. In an ink jet recording head provided on the elastic film and provided with a lower electrode, a piezoelectric layer, and a piezoelectric element including an upper electrode, the piezoelectric layer and the upper electrode constituting the piezoelectric element are configured such that the pressure generation Each region facing the chamber and other than at least a pair of narrow arms extending to the outside of the region facing the pressure generating chamber are formed without extending outside the region, and the lower electrode is formed in each of the pressure generating chambers. Opposing region portions and wiring pattern portions connecting these region portions to each other are formed continuously, and a small number of portions in the facing region portion where the piezoelectric layer constituting the piezoelectric element is not formed are formed. With other between the pair of Hosoude portion is removed, in an ink jet recording head, characterized in that said wiring pattern portion and the opposing area portion between the pair of Hosoude portions are continuous.

In the first aspect, the pattern of the piezoelectric element facing the pressure generating chamber does not extend outside the region facing the pressure generating chamber except for at least a pair of narrow arms, and the lower electrode is formed of the pressure generating chamber. Since most of the area facing the edge is removed, the displacement is greatly improved. In addition, since the narrow arm portion of the piezoelectric element, in which stress is generated by driving, has a small width, it is difficult for cracks or the like to occur, and even if it occurs, it does not affect the main body.

According to a second aspect of the present invention, in the first aspect, an outer edge portion of a region of the peripheral portion of the pressure generating chamber opposite to the portion from which the lower electrode has been removed is opposite to the pressure generating chamber side. On the outside, a narrow band-like layer composed of the piezoelectric layer and the upper electrode is formed along the outer edge without being continuous with the narrow arm of the piezoelectric element. In the recording head.

In the second aspect, when the lower electrode removing portion near the peripheral portion of the pressure generating chamber and the piezoelectric layer of the piezoelectric element and the upper electrode are patterned, a strip-like layer outside the lower electrode removing portion is used. It cuts off the piezoelectric element in the pressure generating chamber and eliminates waste of the driving voltage. This patterning occurs, for example, when two steps are performed while protecting the silicon dioxide film.

According to a third aspect of the present invention, an elastic film forming a part of a pressure generating chamber communicating with a nozzle opening, a lower electrode provided on the elastic film in a region corresponding to the pressure generating chamber, In an ink jet recording head including a piezoelectric layer and a piezoelectric element including an upper electrode, the piezoelectric layer and the upper electrode constituting the piezoelectric element are arranged in each of the regions facing the pressure generating chamber and the pressure generation is performed. The lower electrode is formed so as not to extend outside the region except for at least a pair of narrow arms extending to the outside of the region facing the chamber, and the lower electrode includes a facing region facing the pressure generating chamber and a portion of these regions. And a wiring pattern portion that connects them to each other is continuously formed, and except for at least a portion of the facing region where the piezoelectric layer constituting the piezoelectric element is not formed, except between at least the pair of thin arms. The opposed region portion and the wiring pattern portion are continuous between the pair of thin arm portions, and the piezoelectric layer and the piezoelectric layer along the outer edge portion on the outer edge portion of the wiring pattern portion of the lower electrode. An ink jet recording head is characterized in that a strip-shaped layer comprising the upper electrode is formed.

In the third aspect, the pattern of the piezoelectric element facing the pressure generating chamber does not extend outside the area facing the pressure generating chamber except for at least a pair of narrow arms, and the lower electrode is formed of the pressure generating chamber. Since most of the area facing the edge is removed, the displacement is greatly improved. In addition, since the narrow arm portion of the piezoelectric element, in which stress is generated by driving, has a small width, it is difficult for cracks or the like to occur, and even if it occurs, it does not affect the main body. Further, when removing unnecessary piezoelectric layers and upper electrodes from the entire pattern of the lower electrode, for example, if the patterning is performed twice while protecting the silicon dioxide film, a strip-shaped layer is generated.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the piezoelectric layer constituting the piezoelectric element and the pair of narrow arms of the upper electrode are formed in a longitudinal direction of the piezoelectric element. An ink jet recording head extending from at least one end in the width direction to both sides in the width direction intersecting the longitudinal direction and extending outside a region facing the pressure generating chamber.

In the fourth aspect, a pair of narrow arms are provided at one end in the longitudinal direction of the piezoelectric element, and the lower electrode is connected to the entire pattern between the arms. The inconvenience due to stress on the element is minimized.

According to a fifth aspect of the present invention, in any one of the first to third aspects, the piezoelectric layer constituting the piezoelectric element and the pair of narrow arms of the upper electrode are formed in a longitudinal direction of the piezoelectric element. An ink jet recording head is characterized in that the ink jet recording head is arranged at one side in the width direction crossing the direction and is extended outward and extends outside a region facing the pressure generating chamber.

In the fifth aspect, a pair of narrow arms is provided on one side in the width direction of the piezoelectric element, and the lower electrode is connected to the entire pattern between the narrow arms. This is to minimize inconvenience due to stress on the substrate.

According to a sixth aspect of the present invention, in any one of the first to third aspects, the piezoelectric layer constituting the piezoelectric element and the pair of narrow arms of the upper electrode are provided at a corner of the piezoelectric element. An ink jet recording head is characterized in that the ink jet recording head is arranged so as to sandwich the portion, extends in a direction substantially orthogonal to each other, and extends outside a region facing the pressure generating chamber.

In the sixth aspect, a pair of narrow arms are provided at the corners of the piezoelectric element, and the lower electrode is connected to the entire pattern between the thin arms. The inconvenience caused by stress is reduced as much as possible.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the pressure generating chamber is formed on a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric element is formed of a thin film and a lithographic element. An ink jet recording head characterized by being formed by a 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, in any one of the first to seventh aspects, an insulator layer is formed on an upper surface of the upper electrode, and a lead electrode and the upper electrode are formed on the insulator layer. An ink jet type recording head having a contact hole portion which is a window for forming the contact portion.

In the eighth aspect, each piezoelectric element and the lead electrode are connected through the contact hole.

According to a ninth 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 eighth aspects.

According to the ninth aspect, it is possible to realize an ink jet recording apparatus in which the driving efficiency of the head is improved and the ink can be discharged satisfactorily.

According to a tenth aspect of the present invention, a first step of forming a first layer on a substrate and then sequentially forming a plurality of second and subsequent layers is provided. Patterning all of the layers simultaneously to form an entire pattern of the second layer on the first layer and the second pattern in the entire pattern;
A second step of forming a removed portion to be removed to the layer;
Using the resist pattern that substantially covers the removed portion and the portion substantially surrounded by the removed portion, only the second layer is continuous at at least one location on the boundary between the portion substantially surrounded by the removed portion and another portion. The third and subsequent layers are removed so that the third and subsequent layers are not substantially continuous, and the pattern of the third and subsequent layers in the portion surrounded by the removed portion is the same as the portion where the second layer is continuous. And a third step of performing patterning so as to be substantially surrounded by the portion.

In the tenth aspect, the entire pattern of the second layer formed on the first layer, the removed portion of the second layer formed in the entire pattern, and at least one portion in the removed portion are provided. A plurality of layers including a second layer formed in a part surrounded and excluded, and the part surrounded by the removed part except for one part and the entire pattern are the at least one part. A pattern in which only the second layer is continuous can be formed in two steps using two types of resist patterns. Further, by using a resist pattern that substantially covers the removed portion and a portion substantially surrounded by the removed portion as the two types of resist patterns, the silicon dioxide film at the removed portion can be protected, and the third layer can be protected. It is possible to minimize the continuity between the portion surrounded by the removed portions of the subsequent plural layers and other portions.

According to an eleventh aspect of the present invention, there is provided a first step of sequentially forming an elastic film, a lower electrode, a piezoelectric layer and an upper electrode on a flow path forming substrate in this order, the lower electrode and the piezoelectric layer. And a second step of simultaneously patterning the upper electrode to form an entire wiring pattern of the lower electrode and a removed portion in the wiring pattern that is removed to the lower electrode, and is substantially surrounded by the removed portion. The piezoelectric layer and the upper electrode are removed so that only the lower electrode is continuous and the piezoelectric layer and the upper electrode are not substantially continuous at at least one location on the boundary between the separated portion and the other portion. A third step of patterning the pattern of the piezoelectric layer and the upper electrode in a portion substantially surrounded by the removed portion so as to be substantially surrounded by the portion where the lower electrode is continuous and the removed portion. Characterized by having That in the manufacturing method of the ink jet recording head.

In the eleventh aspect, the entire pattern of the lower electrode formed on the elastic film, the removed portion of the lower electrode formed in the entire pattern, and the removed portion are surrounded except for at least one portion. Lower electrode formed on the part
A pattern having a piezoelectric layer and a pattern of an upper electrode, and a pattern in which only the lower electrode is continuous at a portion surrounded by the removed portion except for one portion and the entire pattern is at least one portion, It can be formed in two steps using two types of resist patterns.

According to a twelfth aspect of the present invention, in the eleventh aspect, the exposed portion is exposed at the removed portion by using a resist pattern substantially covering the portion substantially surrounded by the removed portion and other portions in the third step. A method for manufacturing an ink jet recording head, wherein the vibration film is protected.

In the twelfth aspect, in the third step, the portion where the elastic film is exposed can be protected.

A thirteenth aspect of the present invention is directed to the eleventh or twelfth aspect.
In the aspect, in the third step, a resist pattern shape for forming a pattern of a portion substantially surrounded by the removed portion includes a portion substantially surrounded by the removed portion, a removed portion, and the substantially enclosed portion of the removed portion. And cover a part of the removed portion to cut a continuation of the piezoelectric layer and the upper electrode between the opposite end and the substantially enclosed portion. The present invention provides a method for manufacturing an ink jet type recording head, characterized by having a portion which does not have a portion.

In the thirteenth aspect, the lower electrode, the piezoelectric layer, and the upper electrode are each patterned in the region facing the pressure generating chamber, and the piezoelectric layer and the upper electrode are provided continuously to other portions. It is possible to form a pattern in which only the lower electrode is continuous with the wiring pattern at least at one place with the other part by two-step patterning.

According to a fourteenth aspect of the present invention, in any one of the first to thirteenth aspects, a portion substantially surrounded by the removed portion is a region facing the pressure generating chamber, and faces the pressure generating chamber. In the region, the lower electrode, the piezoelectric layer and the upper electrode are each patterned, and the piezoelectric layer and the upper electrode are not provided continuously to the other portions, and only the lower electrode is provided. Is connected to the wiring pattern at least at one location continuously with the other portions.

[0038] In the fourteenth aspect, an elongated strip-shaped portion of the piezoelectric layer and the upper electrode is formed at the end of the removed portion opposite to the substantially enclosed portion, and the piezoelectric layer and the upper portion of this portion are removed. The continuity between the electrode and the portion of the piezoelectric layer and the upper electrode substantially surrounded by the removed portion is cut, and the protection of the elastic film is maximized.

[0039]

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 shows a cross-sectional structure of one of the pressure generating chambers in the longitudinal direction. FIG.

As shown in the figure, the flow path forming substrate 10 is a silicon single crystal substrate having a plane orientation (110) in this embodiment. As the flow path forming substrate 10, usually 150 to 3
A thickness of about 00 μm is used.
Those having a thickness of about 0 to 280 μm, more preferably about 220 μm are suitable. This is because the arrangement density can be increased while maintaining the rigidity of the partition wall between the adjacent pressure generating chambers.

One surface of the flow path forming substrate 10 is an opening surface, and the other surface is formed with an elastic film 50 having a thickness of 1 to 2 μm and made of silicon dioxide previously formed by thermal oxidation.

On the other hand, the silicon single crystal substrate is anisotropically etched on the opening surface of the flow path forming substrate
A nozzle opening 11 and a pressure generating chamber 12 are formed.

Here, in the anisotropic etching, when a silicon single crystal substrate is immersed in an alkaline solution such as KOH, the substrate is gradually eroded, and the first (111) plane perpendicular to the (110) plane is 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.

On the other hand, each nozzle opening 11 communicating with one end of each pressure generating chamber 12 is formed narrower and shallower than the pressure generating chamber 12. That is, the nozzle opening 11 is formed by partially etching (half-etching) the silicon single crystal substrate in the thickness direction. In addition,
Half etching is performed by adjusting the etching time.

Here, the size of the pressure generating chamber 12 for applying the ink droplet ejection pressure to the ink and the size of the nozzle opening 11 for ejecting the ink droplet depend on the amount of the ejected ink droplet, the ejection speed, and the ejection frequency. Optimized. For example,
When recording 360 ink droplets per inch, the nozzle openings 11 need to be formed with a groove width of several tens of μm with high accuracy.

Further, each pressure generating chamber 12 and a common ink chamber 31 described later are connected to each pressure generating chamber 1 of the sealing plate 20 described later.
The ink is supplied from a common ink chamber 31 through the ink supply communication port 21 formed at a position corresponding to one end of the pressure generation chamber 12. Distributed to

The sealing plate 20 is provided with an ink supply communication port 21 corresponding to each of the pressure generating chambers 12 and has a thickness of, for example, 0.1 to 1 mm and a linear expansion coefficient of 300 ° C. or less. , For example, 2.5-4.5 [× 10 ⁻⁶ / ° C.]. In addition, the ink supply communication port 21
Each of the pressure generating chambers 1 is, as shown in FIGS.
It may be one slit hole 21A crossing the vicinity of the second ink supply side end or a plurality of slit holes 21B. The sealing plate 20 entirely covers one surface of the flow path forming substrate 10 on one surface, and also serves as a reinforcing plate for protecting the silicon single crystal substrate from impact and external force. In addition, the sealing plate 20
The other surface constitutes one wall surface of the common ink chamber 31.

The common ink chamber forming substrate 30 forms the peripheral wall of the common ink chamber 31, and is formed by punching a stainless steel plate having an appropriate thickness according to the number of nozzles and the ink droplet ejection frequency. . In the present embodiment, the thickness of the common ink chamber forming substrate 30 is 0.2 mm.

The ink chamber side plate 40 is made of a stainless steel substrate, and one surface of the ink chamber side plate 40 constitutes one wall of the common ink chamber 31. In the ink chamber side plate 40, a thin wall 41 is formed by forming a concave portion 40a by half etching on a part of the other surface, and an ink introduction port 42 for receiving ink supply from the outside is punched and formed. ing. The thin wall 41 is for absorbing pressure generated at the time of ink droplet ejection toward the side opposite to the nozzle opening 11, and is unnecessary for the other pressure generating chambers 12 via the common ink chamber 31. Prevents positive or negative pressure from being applied.
In the present embodiment, the ink chamber side plate 40 is made 0.2 mm in consideration of rigidity required at the time of connection between the ink introduction port 42 and an external ink supply means, and a part of the thickness is 0.02 mm.
The thickness of the ink chamber side plate 40 may be 0.02 mm from the beginning in order to omit the formation of the thin wall 41 by half etching.

On the other hand, a thickness of, for example, about 0.5 μm
A lower electrode film 60, a piezoelectric film 70 having a thickness of, for example, about 1 μm, and an upper electrode film 80 having a thickness of, for example, about 0.1 μm are formed by lamination in a process to be described later.
0. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric film 70, and the upper electrode film 80. Generally, one of the electrodes of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric film 70 are patterned for each pressure generating chamber 12. Here, a portion which is constituted by one of the patterned electrodes and the piezoelectric film 70 and in which a piezoelectric strain is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion 320. In the present embodiment, the lower electrode film 60 is used as a common electrode of the piezoelectric element 300 and the upper electrode film 80 is used as an individual electrode of the piezoelectric element 300. In any case, the piezoelectric active portion is formed for each pressure generating chamber. Also, here
The combination of the piezoelectric element 300 and the vibration plate whose displacement is generated by driving the piezoelectric element 300 is referred to as a piezoelectric actuator.

In this embodiment, as will be described in detail later,
The piezoelectric film 70 and the upper electrode film 80 are formed for each pressure generating chamber 12, and the lower electrode film 60 of the arm portion of the piezoelectric actuator on both sides in the width direction of the pressure generating chamber 12 is removed to increase the displacement. However, these patterns are devised so that they can be formed in two patterning steps. Along with this, narrow arms 70a and 80a extending outward from the region facing the pressure generating chamber 12 are formed at both ends in the longitudinal direction of the piezoelectric film 70 and the upper electrode film 80 facing each pressure generating chamber 12, respectively. At both ends, the lower electrode film 60
The connection between the portion corresponding to each pressure generating chamber 12 and the entire pattern is achieved.

Here, a process for forming the piezoelectric film 70 and the like on the flow path forming substrate 10 made of a silicon single crystal substrate will be described with reference to FIGS.

As shown in FIG. 4A, first, a wafer of a silicon single crystal substrate serving as the flow path forming substrate 10 is
Thermal oxidation is performed in a diffusion furnace at 0 ° C. to form an elastic film 50 made of silicon dioxide.

Next, as shown in FIG. 4B, a lower electrode film 60 is formed by sputtering. Pt or the like is preferable as the material of the lower electrode film 60. This is because a piezoelectric film 70 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 at such a high temperature and in an oxidizing atmosphere. In particular, when PZT is used for the piezoelectric film 70, the conductivity of the material by diffusion of PbO is increased. It is desirable that there is little change in sex, and Pt is preferred for these reasons.

Next, as shown in FIG. 4C, a piezoelectric film 70 is formed. The piezoelectric film 70 can be formed by a sputtering method, but in the present embodiment, a so-called sol in which a metal organic substance is dissolved and dispersed in a solvent is applied, dried, gelled, and further baked at a high temperature. A so-called sol-gel method for obtaining a piezoelectric film 70 made of a metal oxide is used. As a material for the piezoelectric film 70, a lead zirconate titanate (PZT) -based material is suitable when used in an ink jet recording head.

Next, as shown in FIG. 4D, an upper electrode film 80 is formed. The upper electrode film 80 only needs to be a material having high conductivity, and many metals such as Al, Au, Ni, and Pt, and a conductive oxide can be used. In the present embodiment, P
t is formed by sputtering.

Next, as shown in FIG.
The piezoelectric film 70 and the upper electrode film 80 are patterned.

First, after forming a resist pattern 210 as shown in FIG. 5A, the lower electrode film 60 and the piezoelectric film 7 are formed.
0 and the upper electrode film 80 are etched together, and FIG.
As shown in (1), the entire pattern of the lower electrode film 60 and the lower electrode film removal part 310 are patterned.

Here, the resist pattern 210 is formed, for example, by applying a negative resist HR-100 (manufactured by Fuji Hunt) by spin coating or the like, and performing exposure, development and baking using a mask having a predetermined shape. . Of course, a positive resist may be used instead of the negative resist.

The etching is performed using a dry etching apparatus, for example, an ion milling apparatus, until the elastic film 50 is exposed. In addition, the resist pattern 210
It is removed using an ashing device or the like.

As the dry etching method, a reactive etching method or the like may be used other than the ion milling method.
It is also possible to use wet etching instead of dry etching, but it is preferable to use dry etching because patterning accuracy is somewhat inferior to dry etching and the material of the upper electrode film 80 is limited. .

The lower electrode film removing section 310 is provided in each of the pressure generating chambers 1.
2 (in FIG. 5, before the pressure generating chamber 12 is formed, but indicated by a broken line), the piezoelectric active portion 320
The lower electrode film 60 is removed to remove the lower electrode film 60.
The purpose is to improve the amount of displacement by applying a voltage to zero.

Next, as shown in FIG. 5C, a portion where the elastic film 50 is exposed in a portion other than the entire lower electrode pattern, a region facing the pressure generating chamber 12 and the lower electrode film removing portion 310. Using the resist pattern 220 covering the part,
Only the piezoelectric film 70 and the upper electrode film 80 are etched, and the piezoelectric active portion 320 is patterned as shown in FIG. Cut off. Note that the formation and etching of the resist pattern 220 can be performed in the same manner as in the above-described steps.

The resist pattern 220 used in this step
5 (e) shows an enlarged main part of FIG. Here, the resist pattern 220 basically covers the piezoelectric active portion 320 and the lower electrode film removed portion 310 in a region sandwiched by the lower electrode film removed portion 310, but covers the lower side of the piezoelectric active portion 320. Outside the electrode film removing section 310, the piezoelectric active section 320 is formed so as not to cover the corners 311 at both ends in the longitudinal direction, and to extend to the outside of both longitudinal ends of the lower electrode film removing section 310. ing.

The piezoelectric active portion 3 thus formed
FIG. 6 shows a schematic shape of No. 20. Both ends in the longitudinal direction of the piezoelectric body active portion 320 are widened to form a thin arm portion 321 and have a shape extending to both sides. The piezoelectric film 70 and the upper electrode film 80 constituting the thin arm portion 321 extend to the outside of the pressure generating chamber 12, but the other piezoelectric film 70 and the upper electrode film 80 constituting the piezoelectric active portion 320 are Pressure generating chamber 12
It does not extend outside. The lower electrode film 6 is formed at both ends of the pressure generating chamber 12 between the narrow arms 321.
0 extends to the outside of the pressure generating chamber 12 and is continuous with the entire pattern. Thereby, wiring required for applying a voltage for driving the piezoelectric active section 320 corresponding to each pressure generating chamber 12 can be formed.

The thin arm portion 321 of the piezoelectric active portion 320 extends to the outside of the pressure generating chamber 12, so that it is difficult for cracks or the like to be generated by driving. The crack does not extend to the main body of the piezoelectric active portion 320.

On the other hand, when the piezoelectric active portion 320 is patterned, since the elastic film 50 is exposed in the lower electrode film removing portion 310, it is necessary to protect the elastic film 50 preferably from etching. Therefore, since the resist pattern 220 covers the lower electrode film removing portion 310 in the width direction outside, the narrow band composed of the piezoelectric film 70 and the upper electrode film 80 is provided on both sides of the lower electrode film removing portion 310 in the width direction. Although the portion 330 remains, the piezoelectric active portion 320 and the narrow band portion 330 are separated from each other at the corner 311 of the lower electrode film removing portion 310 to prevent a reduction in efficiency when the piezoelectric active portion 320 is driven. ing.

Although the piezoelectric film 70 and the upper electrode film 80 other than the piezoelectric active portion 320 are basically removed, the elastic film 50 is exposed in a portion other than the entire pattern of the lower electrode film 60. Similarly, in order to protect this portion from etching, the resist pattern 220 is formed so as to cover the outer peripheral portion of the entire pattern of the lower electrode film 60. Therefore, as shown in FIG. 7A, a narrow band portion 350 including the piezoelectric film 70 and the upper electrode film 80 is formed on the outer peripheral portion of the entire lower electrode film pattern 340. Note that the upper electrode film 80 on the narrow band portion 350 may be removed.

Further, the narrow band portion 330 and the piezoelectric active portion 320
7 need not be cut off from the thin arm portion 321 of FIG.
As shown in (b), the periphery of the lower electrode film removing section 310 may be surrounded by the piezoelectric active section 320 and the narrow band section 330. In this case, the upper electrode film 80 on the narrow band 330 may be removed in consideration of a reduction in efficiency during driving.

As described above, first, the lower electrode film 60
Is patterned in two steps by simultaneously patterning the entire pattern of the lower electrode film removing portion 310 and the lower electrode film removing portion 310 and a resist pattern covering a region facing the pressure generating chamber 12. Is completed.

As described above, after patterning the lower electrode film 60 and the like, it is preferable to provide electrical insulation so as to cover at least the periphery of the upper surface of each upper electrode film 80 and the side surfaces of the piezoelectric film 70. An insulator layer 90 is formed (see FIG. 1). Here, the insulator layer 90 is made of a material that can be formed by a film forming method or shaped by etching, for example, silicon oxide, silicon nitride, an organic material, preferably a photosensitive polyimide having low rigidity and excellent electrical insulation. It is preferred to form with.

Then, each piezoelectric active portion 3 of the insulator layer 90
A contact hole 90a that exposes a part of the upper electrode film 80 for connecting to a lead electrode 100 described later is formed in a part of the part that covers the upper surface of the part corresponding to one end of 20. One end is connected to each upper electrode film 80 via the contact hole 90a, and the other end is formed with a lead electrode 100 extending to the connection terminal portion. The lead electrode 100 is formed so as to be as narrow as possible so as to reliably supply a drive signal to the upper electrode film 80.

FIG. 8 shows a process of forming such an insulator layer.
Shown in

First, as shown in FIG. 8A, an insulator layer 90 is formed so as to cover the periphery of the upper electrode film 80, the side surfaces of the piezoelectric film 70, and the side surfaces of the lower electrode film 60. Suitable materials for the insulator layer 90 are as described above, but in the present embodiment, a negative photosensitive polyimide is used.

Next, as shown in FIG. 8B, by patterning the insulator layer 90, each of the pressure generating chambers 12 is formed.
A contact hole 90a is formed in a portion corresponding to the vicinity of the end on the ink supply side. This contact hole 90a
Is for connecting a lead electrode 100 and an upper electrode film 80 described later. The contact hole 90
“a” may be provided at another part of the pressure generating chamber 12, for example, at the center or the end on the nozzle side.

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

The above is the film forming process. After forming the film in this manner, as shown in FIG. 8C, the silicon single crystal substrate is subjected to anisotropic etching with the above-described alkali solution to form the pressure generating chamber 12 and the like. In addition,
In the series of film formation and anisotropic etching described above, a number of chips are simultaneously formed on one wafer, and after completion of the process, each of the flow path forming substrates 10 having one chip size as shown in FIG. To divide. Further, the divided flow path forming substrate 10 is sequentially adhered and integrated with the sealing plate 20, the common ink chamber forming substrate 30, and the ink chamber side plate 40 to form an ink jet recording head.

The ink jet head thus configured takes in ink from an ink inlet 42 connected to an external ink supply means (not shown), fills the interior from the common ink chamber 31 to the nozzle opening 11 with ink, and
In accordance with a recording signal from an external drive circuit (not shown), a voltage is applied between the lower electrode film 60 and the upper electrode film 80 via the lead electrode 100, and the elastic film 50, the lower electrode film 60, and the piezoelectric film 70 The pressure generating chamber 1 is deformed by bending.
The pressure in 2 increases, and ink droplets are ejected from nozzle opening 11.

(Embodiment 2) FIG. 9 shows the shapes of a piezoelectric active portion and a pressure generating chamber of an ink jet recording head according to Embodiment 2 of the present invention.

In this embodiment, the piezoelectric active portion 320 has a narrow arm portion 321A only at one end, and the U-shaped lower electrode film removing portion is provided at a portion other than between the narrow arm portions 321A of the piezoelectric active portion 320. This embodiment differs from the first embodiment in that 310A is formed. In this embodiment, the lower electrode film 60 in a region facing the pressure generating chamber 12 and the lower electrode film 60 of the entire wiring pattern are continuous only between the narrow arms 321A. The U-shaped narrow band portion 33 is provided outside the lower electrode film removing portion 310A.
0A is formed separately from the piezoelectric active portion 320.

The manufacture of the ink jet recording head of this embodiment can be performed by the same process as that of the first embodiment, and the operation and effect are the same as those of the first embodiment.

(Embodiment 3) FIG. 10 shows the shapes of a piezoelectric active portion and a pressure generating chamber of an ink jet recording head according to Embodiment 3 of the present invention.

This embodiment is the same as Embodiment 2 except that the narrow arm 321B of the piezoelectric active section 320 is provided on one side in the width direction of the pressure generating chamber 12, and the narrow arm 321B of the piezoelectric active section 320 is provided. The lower electrode film removing portion 31
0B is formed. Also in this embodiment, the lower electrode film 60 facing the pressure generating chamber 12 and the lower electrode film 60 of the entire wiring pattern are continuous only between the narrow arms 321B. Note that a narrow band portion 330B is formed outside the lower electrode film removing portion 310B separately from the piezoelectric active portion 320.

The manufacture of the ink jet recording head of this embodiment can be performed by the same process as that of the first embodiment, and the operation and effect are the same as those of the first embodiment. In addition,
In the present embodiment, the thin arm portion 321B of the piezoelectric body active portion 320 is used.
Is provided on the side of the pressure generating chamber 12 where the deformation is relatively large. However, since the width of the narrow arm portion 321B is small, cracks and the like hardly occur due to stress. There is no danger of affecting.

(Embodiment 4) FIG. 11 shows the shapes of a piezoelectric active portion and a pressure generating chamber of an ink jet recording head according to Embodiment 4 of the present invention.

The present embodiment is the same as the second embodiment except that the narrow arm 321C of the piezoelectric active section 320 is provided at one corner of the pressure generating chamber 12, and the thin arm 3 of the piezoelectric active section 320 is provided.
The lower electrode film removed portion 310C is formed in a portion other than the portion between 21C. Also in this embodiment, the lower electrode film 60 facing the pressure generating chamber 12 and the lower electrode film 60 of the entire wiring pattern are continuous only between the narrow arms 321B.
Note that the narrow band portion 33 is provided outside the lower electrode film removal portion 310C.
OC is formed separately from the piezoelectric active portion 320.

The manufacture of the ink jet recording head of this embodiment can be performed by the same process as that of the first embodiment, and the operation and effect are the same as those of the first embodiment. In addition,
In this embodiment, the thin arm portion 321C of the piezoelectric body active portion 320 is used.
Is provided at the corner with the least amount of deformation,
The stress applied to C is reduced, and the possibility of occurrence of cracks and the like is reduced.

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

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

In the above-described embodiment, the nozzle openings are formed on the end surface of the flow path forming substrate 10. However, the nozzle openings may be formed to project in a direction perpendicular to the surface.

FIG. 12 is an exploded perspective view of the embodiment configured as described above, and FIG. 13 is a cross-sectional view of the flow path thereof. In this embodiment, the nozzle opening 11 is formed in the nozzle substrate 120 opposite to the piezoelectric element, and the nozzle communication port 22 that connects the nozzle opening 11 and the pressure generating chamber 12 is formed with the sealing plate 20 and the common ink chamber. It is arranged so as to penetrate the forming plate 30, the thin plate 41A, and the ink chamber side plate 40A.

The present embodiment is different from the first embodiment in that
A is basically the same as the above-described embodiment except that the ink chamber side plate 40A and the ink chamber side plate 40A are separate members, and the opening is formed in the ink chamber side plate 40. Is omitted.

In each of the embodiments described above, a thin film type ink jet recording head which can be manufactured by applying a film forming and lithography process is described as an example.
Of course, the present invention is not limited to this. For example, a piezoelectric film is formed by laminating substrates to form a pressure generating chamber, or a piezoelectric film is formed by attaching a green sheet or by screen printing, or a piezoelectric film formed by crystal growth. The present invention can be applied to ink jet recording heads having various structures, such as those that form a recording medium.

Further, in the above embodiment, the example in which the insulator layer is provided between the piezoelectric element and the lead electrode has been described.
The present invention is not limited to this. For example, without providing an insulator layer, an anisotropic conductive film is thermally welded to each upper electrode, and this anisotropic conductive film is connected to a lead electrode. The connection may be made using various bonding techniques.

As described above, the present invention can be applied to ink-jet recording heads having various structures, as long as the gist of the present invention is not contradicted.

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 or 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. 14, recording head units 1A and 1B having an ink jet recording head are
Cartridges 2A and 2B constituting ink supply means are provided detachably, and 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, 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.

[0101]

As described above, in the present invention,
The portion of the piezoelectric element that extends beyond the region facing the pressure generating chamber is a pair of narrow arms formed to be thin, and the lower electrode film in the region facing the pressure generating chamber other than the portion facing the piezoelectric element is the largest. Since the lower electrode film, which is partially removed and faces the pressure generating chamber, and the lower electrode film of the entire wiring pattern are continuous between the narrow arms, the amount of deformation can be maximized. There is an effect that the device can be manufactured without a risk of destruction or the like and without increasing the number of patterning steps.

[Brief description of the drawings]

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

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

FIG. 3 is a view showing a modification of the sealing plate of FIG. 1;

FIG. 4 is a diagram showing a thin film manufacturing process according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a thin film manufacturing process according to the first embodiment of the present invention.

FIG. 6 is a plan view showing a main part of the first embodiment of the present invention.

FIG. 7 is a plan view showing a main part of the first embodiment of the present invention.

FIG. 8 is a diagram illustrating a process of forming an insulator layer and a pressure generating chamber according to the first embodiment of the present invention.

FIG. 9 is a plan view showing a main part of a second embodiment of the present invention.

FIG. 10 is a plan view showing a main part of a third embodiment of the present invention.

FIG. 11 is a plan view showing a main part of a fourth embodiment of the present invention.

FIG. 12 is an exploded perspective view of an ink jet recording head according to another embodiment of the present invention.

FIG. 13 is a cross-sectional view illustrating an ink jet recording head according to another embodiment of the present invention.

FIG. 14 is a perspective view schematically showing 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 nozzle opening 12 pressure generating chamber 50 elastic film 60 lower electrode film 70 piezoelectric film 80 upper electrode film 90 insulating layer 90a contact hole 100 lead electrode 300 piezoelectric element 310 lower electrode film removing portion 320 piezoelectric active Part 321 thin arm part

Claims (14)

[Claims] 1. An elastic film forming a part of a pressure generating chamber communicating with a nozzle opening, and a lower electrode, a piezoelectric layer, and an upper electrode provided on the elastic film in a region corresponding to the pressure generating chamber. In the ink jet type recording head provided with a piezoelectric element, the piezoelectric layer and the upper electrode constituting the piezoelectric element are provided for each region facing the pressure generation chamber and to the outside of the region facing the pressure generation chamber. The lower electrode is formed so as not to extend outside the region except at least a pair of narrow arms, and the lower electrode is a wiring pattern portion connecting the opposing region portions facing the pressure generating chambers and the portions of these regions to each other. Are continuously formed, and a portion of the opposing region where the piezoelectric layer constituting the piezoelectric element is not formed is removed except at least between the pair of narrow arms, and the pair of narrow arms are removed. An ink jet recording head, characterized in that said facing region portion and the wiring pattern portion is continuous between parts. 2. The pressure generating chamber according to claim 1, wherein a peripheral portion of the peripheral portion of the pressure generating chamber opposite to a portion from which the lower electrode is removed has an outer peripheral portion opposite to the pressure generating chamber side. An ink-jet recording head, wherein a narrow band-like layer comprising the piezoelectric layer and the upper electrode is formed along and without being continuous with the narrow arm portion of the piezoelectric element. 3. An elastic film forming a part of a pressure generating chamber communicating with a nozzle opening, and a lower electrode, a piezoelectric layer, and an upper electrode provided on the elastic film in a region corresponding to the pressure generating chamber. In the ink jet type recording head including the piezoelectric element, the piezoelectric layer and the upper electrode forming the piezoelectric element are provided for each area facing the pressure generating chamber and outside the area facing the pressure generating chamber. The lower electrode is formed so as not to extend outside the region except at least a pair of narrow arms, and the lower electrode is a wiring pattern portion connecting the opposing region portions facing the pressure generating chambers and the portions of these regions to each other. Are continuously formed, and a portion of the opposing region where the piezoelectric layer constituting the piezoelectric element is not formed is removed except at least between the pair of narrow arms, and the pair of narrow arms are removed. The opposed region portion and the wiring pattern portion are continuous between the portions, and a thin layer formed of the piezoelectric layer and the upper electrode on the outer edge portion of the wiring pattern portion of the lower electrode along the outer edge portion. An ink jet recording head comprising a band-like layer. 4. The piezoelectric element according to claim 1, wherein the pair of narrow arms of the piezoelectric layer and the upper electrode forming the piezoelectric element are arranged at least from one end in the longitudinal direction of the piezoelectric element. An ink jet recording head, which extends to both sides in the width direction crossing the direction and extends outside a region facing the pressure generating chamber. 5. The piezoelectric element according to claim 1, wherein the pair of narrow arms of the piezoelectric layer and the upper electrode constituting the piezoelectric element are arranged in a width direction crossing a longitudinal direction of the piezoelectric element. An ink jet recording head, which is arranged at one side with an interval, extends outward, and extends outside a region facing the pressure generating chamber. 6. The piezoelectric element according to claim 1, wherein the pair of narrow arms of the piezoelectric layer and the upper electrode constituting the piezoelectric element are disposed with a corner of the piezoelectric element interposed therebetween. An ink jet recording head extending in a direction substantially orthogonal to and extending outside a region facing the pressure generating chamber. 7. The pressure generating chamber according to claim 1, wherein the pressure generating chamber is formed on a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric element is formed by a thin film and a lithography method. An ink jet recording head, characterized in that: 8. The semiconductor device according to claim 1, wherein an insulator layer is formed on an upper surface of the upper electrode, and the insulator layer has a contact portion for forming a contact portion between a lead electrode and the upper electrode. An ink jet recording head having a contact hole portion serving as a window. 9. An ink jet recording apparatus comprising the ink jet recording head according to claim 1. 10. A first step of forming a first layer on a substrate and further forming a plurality of layers subsequent to a second layer,
All of the plurality of layers on the first layer are simultaneously patterned to form an entire pattern of the second layer on the first layer, and a removed portion in the entire pattern and removed to the second layer. A second step of forming at least one portion of a boundary between the portion substantially surrounded by the removed portion and another portion by using a resist pattern substantially covering the removed portion and the portion substantially surrounded by the removed portion. So that only the second layer is continuous and the third and subsequent layers are not substantially continuous.
The third and subsequent layers are removed so that the pattern after the third layer in the portion surrounded by the removed portion is substantially surrounded by the portion where the second layer is continuous and the removed portion. A patterning method comprising the steps of: 11. A first step of sequentially forming an elastic film, a lower electrode, a piezoelectric layer and an upper electrode on a flow path forming substrate in this order, and simultaneously patterning the lower electrode, the piezoelectric layer and the upper electrode. And the entire wiring pattern of the lower electrode,
A second step of forming a removed portion in the wiring pattern to be removed to the lower electrode; and forming the lower electrode at at least one position on a boundary between a portion substantially surrounded by the removed portion and another portion. Only the piezoelectric layer and the upper electrode are removed so that the piezoelectric layer and the upper electrode are not substantially continuous, and the piezoelectric layer and the upper portion of the portion substantially surrounded by the removed portion are removed. A third step of patterning an electrode pattern such that the electrode pattern is substantially surrounded by a portion where the lower electrode is continuous and the removed portion. 12. The method according to claim 11, wherein in the third step, the elastic film exposed at the removed portion is protected by using a resist pattern substantially covering the portion substantially surrounded by the removed portion and other portions. A method for manufacturing an ink jet recording head. 13. The resist pattern shape according to claim 11, wherein a resist pattern shape for forming a pattern of a portion substantially surrounded by the removed portion in the third step includes a portion substantially surrounded by the removed portion and a removed portion. In order to cover the end of the removed portion opposite to the substantially enclosed portion and to cut off the continuity of the piezoelectric layer and the upper electrode between the opposite end and the substantially enclosed portion. A method for manufacturing an ink jet recording head, comprising a part that does not cover a part of the removed part. 14. The method according to claim 11, wherein
A portion substantially surrounded by the removed portion is a region facing the pressure generating chamber, and the lower electrode, the piezoelectric layer, and the upper electrode are patterned in the region facing the pressure generating chamber, The body layer and the upper electrode are not provided continuously up to the other portion, and only the lower electrode is connected to the wiring pattern at least at one location continuously with the other portion. A method for manufacturing an ink jet recording head, which is characterized by the following.