JP2003182069A - Ink jet head and method of manufacturing the same - Google Patents

Abstract

(57) [Problem] To improve the reliability of electrical connection between an electrode and a flexible substrate without significantly increasing the production cost, thereby improving the production yield of an ink jet head. SOLUTION: An ink jet head 100 of the present invention.
Comprises a base member 1 made of a piezoelectric material and having a plurality of grooves for forming an ink flow path, and a metal film electrically connected to a metal electrode 13 formed on a side surface of the groove in the base member 1. Is formed on the upper surface of the side wall 11 between the grooves, and the flexible substrate 41 is connected to the metal film with an anisotropic conductive resin or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure and a manufacturing method of an electrode film used in an ink jet head, and more particularly to a structure for drawing out an electrode film.

[0002]

2. Description of the Related Art In recent years, non-impact printing apparatuses such as ink jet systems, which are suitable for colorization and multi-gradation, have rapidly spread in place of impact printing apparatuses. Above all,
The drop-on-demand type, which discharges the ink required only during printing, is drawing attention because of its good printing efficiency, low cost, and low running cost. Method and thermal jet method are the mainstream.

However, the Kaiser system has a drawback that it is difficult to miniaturize and is not suitable for high density. Further, although the thermal jet method is suitable for high density, it generates bubbles in the ink by heating the heater and uses the energy of the bubbles to eject the ink. There is a problem in that the requirement for the heat resistance is strict, it is difficult to extend the life of the heater, and the power consumption is increased.

In order to solve such a drawback, an ink jet method utilizing a shear mode of a piezoelectric material has been proposed. In this method, an electrode formed on the ink channel wall made of a piezoelectric material applies an electric field in a direction orthogonal to the polarization direction of the piezoelectric material to deform the channel wall in shear mode and use the pressure wave fluctuations that occur at that time. Ink droplets are then ejected, which is suitable for high density nozzles, low power consumption, and high driving frequency.

An example of the structure of an ink jet head using such a shear mode will be described with reference to FIGS. 8 (a) and 8 (b). This structure is a structure separately proposed by the same applicant as the present application, and is characterized in that the ink jet head is electrically connected to the outside through a conductive resin embedded in the ink channel.

The ink jet head 100 includes a base member 1 in which a plurality of grooves 4 are formed in a piezoelectric body polarized in the vertical direction in the figure, a cover member 2 in which an ink supply port and a common ink chamber are formed, and a nozzle. The ink channel 16 is formed by laminating the nozzle plate 9 provided with the holes 10. An electrode for applying an electric field is formed in the upper half of the channel wall.

An insulating film is formed in the ink channel 16 in order to avoid contact between the electrode 5 and the ink. The conductive member 2 is provided at the rear end of the ink channel 16.
6 is embedded, and the conductive member 26 is provided in the ink channel 1.
6 is exposed on the rear end face. A flexible substrate 41 is bonded to the rear end surface of the ink channel 16 where the conductive member 26 is exposed by an anisotropic conductive adhesive, and the wiring of the flexible substrate 41 and the electrode 5 are electrically connected.

A method for forming the electrode 5 in the ink jet head having the above structure will be described with reference to FIGS.

With reference to FIG. 9 (a), vapor deposition particles are made incident on a base member 1 having a plurality of grooves 4 formed therein from a first direction 53 inclined from the normal direction, and self-forming of walls forming the grooves is performed. Due to the shadowing effect, only the first wall above the first wall
The electrode film 51 is formed.

Next, referring to FIG. 9B, the vapor deposition particles are incident from a second direction 54 which is substantially mirror-symmetrical with respect to the normal to the base member from the incident direction of the vapor deposition particles, and the vapor deposition particles are above the other wall surface. The second electrode film 52 is formed only on the above.

Next, referring to FIG. 9C, the electrode film formed on the upper end of the wall is removed by a method such as etching or grinding to form an electrode 5.

In driving the ink jet head, since the same potential is applied to the electrodes 5 facing each other through the groove 4, it is necessary that the electrodes 5 are electrically connected through the groove 4. Conventionally, the conductive member 26 is buried in the groove 4 as described above in order to secure the conduction.

On the other hand, as a method of forming electrodes, instead of obliquely depositing as described above, Japanese Patent Laid-Open No. 10-2446 is used.
Japanese Patent No. 68 discloses a method of forming an electrode film on the entire surfaces of a wall and a groove and then removing only the upper surface of the side wall by photolithography.

[0014]

The ink jet head having the conventional structure as described above has the following problems.

That is, in the conventional head having the above-mentioned structure, the flexible substrate 41 is electrically connected to the conductive member 26 exposed on the rear end surface of the ink channel with an anisotropic conductive resin or the like. Although silver paste was used as the conductive member 26, the exposed surface is damaged by mechanical processing such as dicing to expose the rear end surface, and the conductive member 26 has fine cracks, which increases the resistance value. Was causing poor continuity. Further, the natural oxide film formed on the surface of the electrode film prevents contact between the conductive member 26 and the electrode film, causing an increase in resistance value and poor conduction. Therefore, the reliability of the electrical connection between the flexible substrate 41 and the conductive member 26 or between the conductive member 26 and the electrode 5 is low. As a result, there has been a problem that defective connections occur in some channels, malfunctions in the ink channels, and a consequent reduction in yield.

Furthermore, in the method of manufacturing the conventional head having the above structure, the electrode 5 is formed by utilizing the self-shadowing effect by oblique vapor deposition, so that the reproducibility of the electrode width is unstable, which causes ink jetting. There is a problem that the ejection characteristics of the head change.

The present invention has been made in order to solve the above problems, and does not cause a significant increase in manufacturing cost.
The purpose of the present invention is to improve the reliability of the electrical connection between the electrode in the ink channel and the flexible substrate, thereby improving the manufacturing yield of the inkjet head.

[0018]

An ink jet head of the present invention comprises a substrate having a plurality of grooves and made of a piezoelectric material, a first conductive film portion such as a metal film formed on a side surface of the groove, and a space between the grooves. A second conductive film portion such as a metal film formed on the upper surface of the partition wall (side wall) and electrically connected to the first conductive film portion.

In this structure, the first conductive film portion serving as an electrode can be connected to the conductive layer pattern on the flexible substrate via the second conductive film portion formed on the upper surface of the partition wall (side wall). At this time, there is no mechanical damage to the flexible substrate and the conductive film portion, and even if a natural oxide film is formed on the surface of the conductive film portion, it is possible to easily set the pressure when connecting the flexible substrate to a high level. The flexible substrate and the conductive film portion can be connected by breaking through the natural oxide film. Therefore, the electrical reliability is increased.

It is preferable to provide a gap for separating the second conductive film portions formed on the adjacent partition walls on the side surface of the groove or the upper surface of the partition wall.

According to this structure, the first conductive film portion serving as an electrode can be easily separated for each channel.

It is preferable that the first conductive film portions formed on the opposite side surfaces of the groove are electrically connected via the third conductive film portion such as a metal film formed on the bottom surface of the groove.

According to this structure, the first conductive film portions facing each other through the groove can be electrically connected without using a conductive member such as paste, so that the first conductive film portions are electrically connected to each other. In this case, the reliability of the connecting portion can be improved. .

It is preferable to integrally form the first conductive film portion and the third conductive film portion. According to this configuration, since it is not necessary to form the conductive member in a separate step in order to electrically connect the first conductive film portions facing each other through the groove, it is possible to increase the number of steps of the inkjet head without increasing. The first conductive film portions can be electrically connected to each other.

The first, second and third conductive film portions are formed of A
It is preferably made of a metal film containing 1, Cu or Ni as a main component.

According to this structure, since simple wet etching can be used when forming the electrodes, the manufacturing process of the head can be simplified.

The method of manufacturing an ink jet head of the present invention comprises a step of forming a conductive film so as to cover the grooves and partition walls of a substrate having a plurality of grooves and partition walls between the grooves and made of a piezoelectric material. Of photoresist on the surface, a step of selectively exposing the photoresist to form a photoresist pattern, and a conductive film is processed using the photoresist pattern to select on the side surface of the groove and on the partition wall. And leaving a conductive film, while forming a gap for separating the conductive films formed on the adjacent partition walls.

In this ink jet head manufacturing method, the conductive film pattern including the electrode pattern and the gap pattern can be formed by photolithography, so that the manufacturing throughput can be improved as compared with the mechanical processing such as the dicing method. .

The step of forming the photoresist pattern includes the step of forming the photoresist pattern by irradiating the photoresist with exposure light such as ultraviolet rays from a direction oblique to the direction normal to the substrate.

Thus, by irradiating the photoresist with the exposure light obliquely, the shadow of the wall between the grooves is projected on the side surface of the opposing wall, that is, the self-shadowing effect by the wall is utilized to make the electrode. A shaped photoresist pattern can be formed. As a result, the electrode pattern can be formed reproducibly with less wraparound during the pattern formation, as compared with the case where the electrode pattern is formed by utilizing the self-shadowing effect of the wall during vapor deposition. In addition, since a special mask pattern is not formed on the side wall, alignment work between the mask and the substrate is not required, and workability is very good.

In the photoresist pattern forming step, the exposure light is obliquely applied to the photoresist on the second portion while blocking the exposure light on the photoresist on the first portion of the substrate. Step, and the photoresist on the first portion is selectively exposed to the exposure light from a direction that is substantially mirror-symmetrical to the irradiation direction of the exposure light in the first exposure step with respect to the normal direction of the substrate (opposite side with respect to the normal direction of the substrate). And a second exposure step of irradiating the photoresist on the second portion with the exposure light.

According to this, the photoresist applied on the second portion (for example, the portion on the nozzle plate 9 side in FIG. 1) is exposed obliquely from two directions which are substantially mirror-symmetrical with respect to the normal line direction of the substrate. Can be performed to form a photoresist pattern for forming an electrode pattern, and the exposure light is selectively applied to the photoresist applied on the first portion (for example, the portion opposite to the nozzle plate 9 in FIG. 1). Can be irradiated to form a photoresist pattern for the gap pattern. Therefore, the exposure for forming the photoresist pattern for forming the electrode pattern and the photoresist pattern for forming the gap pattern can be performed at the same time, so that the throughput can be improved and the manufacturing cost can be reduced.

The conductive film is preferably processed by a wet etching method. According to this method, since the etching proceeds isotropically, it is possible to uniformly process a conductive film such as a metal film formed on a side surface of a groove of a member having an uneven surface such as an inkjet head.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
It will be described in detail with reference to FIG.

(Embodiment 1) FIG. 1 shows an ink jet head (ink jet printer head) 1 according to the present invention.
00 shows a perspective view of a part of the No. 00 in the channel direction. That is, as shown in FIG. 1, the inkjet printer head 100 includes a base member (substrate) 1, a cover member 3,
The nozzle plate 9 and the flexible substrate 41 are provided.

The base member 1 is made of a lead zirconate titanate (PZT) -based ceramic material having ferroelectricity. The base member 1 is, as shown in FIG.
The plate has a thickness of about 1 mm and is polarized in the direction of arrow 7.

The base member 1 is provided with a plurality of grooves 4 serving as ink flow paths, which are formed by cutting by rotating a diamond cutting disk. Each groove 4 is parallel and has the same depth. Each groove 4 has a depth of about 300 μm, a width of about 79 μm, and a pitch of 169 μm. And groove 4
Lower half and bottom of both side surfaces and side wall (partition wall) 11
The metal electrode 13 is formed in a predetermined shape on a part of the upper surface of the.

FIG. 3A is a sectional view of IIIA-IIIA of FIG.
It is a line sectional view. As shown in FIG. 3A, in the IIIA-IIIA line cross section on the side closer to the nozzle plate 9 that ejects ink, the metal electrodes 13 are formed on the lower half and the bottom portion 15 of both side surfaces of the groove 4.
It is formed only on.

FIG. 3B is a sectional view taken along line IIIB-IIIB in FIG. In the figure, the metal electrode 13 is the base member 1.
Is formed on almost the entire surface of the groove 4, but a slit 27 is formed on a part of one side surface of the groove 4. Thereby,
The electrodes in each ink flow path are separated and electrically separated.

Here, it is desirable that the position of the slit 27 is as close to the upper end of the side surface of the groove 4 as possible. Further, in the present embodiment, the width of the slit 27 is 10
Although the width is set to μm, it is desirable that the width of the slit 27 is as small as possible.

As shown in FIG. 3 (c), the slit 27
May be disposed on the upper surface 14 of the side wall within a range in which the connection reliability between the metal electrode 13 and the electrode of the flexible substrate 41 is not significantly deteriorated and the electrode of the adjacent channel is not short-circuited.

The slit 27 is formed so as to remove a part of the metal film on the side surface of the groove 4 or a part of the metal film on the upper surface 14 of the side wall.

As described above, the metal electrode (first conductive film portion) 13 formed on the side wall facing the groove 4 is the metal electrode (third conductive film portion) 13 formed on the bottom portion 15 of the groove 4. Since the electrodes are electrically connected via, the reliability of the connection is higher than that in the case where both electrodes are connected using a conductive paste, for example. As a material of the metal electrode 13, aluminum, nickel, copper or the like is used.

As described above, the electrode films formed on both side surfaces of the groove 4 and the bottom portion 15 extend to the upper surface of the side wall 11, and the metal film portion (second conductive film portion) on the upper surface of the side wall 11 is formed. The metal electrodes 13 on each side wall 11 are connected to each other.
The slit 27 is provided in a part of the electrode film as shown in FIG.
Is divided by. As a result, the electrodes of the adjacent ink flow paths are separated from each other and electrically separated.

Therefore, it is possible to apply the same electric potential to the electrodes in one ink flow path and apply the opposite electric potential to the electrodes of the adjacent ink flow paths to deform the side wall in the shear mode.

Next, referring again to FIG. 1, of the parts which are in contact with each other when the base member 1 and the cover member 3 are joined, the part which is not the attaching surface of the nozzle plate 9 (first part)
An insulating resin 22 such as an epoxy resin is embedded in the groove 4 of the portion) by a method such as a dispenser or printing. This resin 22 prevents the ink from leaking from the opposite side of the nozzle when the inkjet head is operated, and restricts the movement of the walls on both sides of the groove 4 to ensure a stable ink ejection operation. Buried.

Further, in the present embodiment, it is described in the drawings that the region where the metal electrode 13 is provided on the upper surface of the side wall 11 and the region where the resin 22 is embedded do not overlap with each other.
For the purpose of the present invention, the metal electrode 13 is the side wall 11
There is no problem even if the region provided on the upper surface of the and the region where the resin 22 is embedded overlap each other.

Then, the surface of the base member 1 on the side where the groove 4 is processed and the cover member 3 are adhered to each other with an adhesive such as an epoxy-based adhesive (not shown) to form an ink flow path.

Further, as shown in FIG. 3D, a flexible substrate 41 having a conductive layer pattern 42 formed on the metal electrode 13 formed on the upper surface 14 of the side wall corresponding to the position of each ink flow path is formed. Connecting. The conductive layer pattern 4
2 and the metal electrode 13 formed on the upper surface 14 of the side wall,
It is electrically connected using an anisotropic conductive adhesive or solder (not shown).

FIG. 4 is a perspective view of the head of FIG. 1 when viewed from the opposite side. The nozzle plate 9 is bonded to an end surface (an end surface on the second portion side) which is composed of the base member 1 and the cover member 3 and to which the flexible substrate 41 is not connected. Nozzle holes 10 are provided in the nozzle plate 9 at positions corresponding to the positions of the ink channels. Then, a manifold (not shown) is joined to the ink inflow hole 34 provided in the cover member 3.

Further, referring to FIG. 1, resin (not shown) is injected into the ink channel from the end surface (end surface on the first portion side) 35 of the base member 1 to which the flexible substrate 41 is connected to prevent double ink leakage. It is desirable to do.

In the first embodiment described above, the first conductive film portion formed on the side surface of the groove 4 on the surface of the base member 1 and the second conductive film portion formed on the side wall 11 between the grooves 4, The example in which the third conductive film portion formed on the bottom surface of the groove 4 is formed of an integral metal film has been described, but each conductive film portion may be formed of a separate member. Further, as each conductive film portion, a conductive film other than a metal film can be used, and conductive films of different materials can also be used in combination.

(Embodiment 2) Next, a method of manufacturing an ink jet head according to the present invention, in particular, a method of forming an electrode pattern will be described with reference to FIGS.

FIGS. 5A to 5E show IIIA-I in FIG.
It is a process drawing of a IIA line section. In addition, FIG.
(E) is a process drawing of a section taken along line IIIB-IIIB in FIG. 1.

First, referring to FIGS. 5A and 6A,
A metal electrode film 12 made of Cu and having a thickness of 1 μm is formed by vapor deposition on the base member 1 on which the groove 4 having a width of 79 μm and a depth of 300 μm is processed.

At this time, the base member 1 is inclined during the vapor deposition operation so that the metal film is sufficiently formed even on the bottom of the groove 4, and the deposition is performed while changing the flying direction of the vapor deposition particles with respect to the base member 1. .

In the present embodiment, the metal electrode film 12 is formed by the vapor deposition method, but other than this, a plating method, a sputtering method, a CVD (Chemical Vapor Deposition) method.
The method etc. can be used.

In the present embodiment, the metal electrode film (first conductive film portion) formed on the opposite side surfaces of the groove 4 and the metal electrode film at the bottom of the groove 4 for electrically connecting these electrode films ( Third
Since the conductive film portion) is manufactured in the same process, a process such as burying a conductive paste is not necessary.

Next, after applying the positive photoresist 20, ultraviolet rays 21 are irradiated from an oblique direction inclined by about 21 ° from the normal direction of the base member 1 to perform the first exposure step.

The positive photoresist 20 is applied by a spray method and dried in an oven at 90 ° C. for 20 minutes. Normally, when a resist is applied to such a groove-shaped member, it is applied thickly to the bottom of the groove 4 and the side wall 11
There is a tendency to be applied thinly on the upper surface of, which causes uneven exposure.

However, in this step, the resist 20 on the upper surface of the side wall 11 is removed by development as will be described later, so that the resist 20 on the upper surface of the side wall 11 becomes thin and the resist 20 is easily exposed. , Resist 2
It becomes easy to remove 0.

Further, as can be seen from the comparison between FIG. 5A and FIG. 6A, when performing the above-mentioned exposure, III of FIG.
In the vicinity of the section taken along the line A-IIIA (the second portion of the base member 1), a photomask having no light-shielding pattern is used, and the entire surface of the portion is irradiated with the ultraviolet rays 21. This causes the shadows of all the walls to be projected through the grooves 4 onto the opposing wall surfaces, exposing an area of about 200 μm above.

On the other hand, referring to FIG. 6A, II of FIG.
Near IB-IIIB line cross section (first portion of base member 1)
Then, the first photomask 18 having a mask pattern (light-shielding pattern) that completely blocks the ultraviolet rays 21 is used, and the exposed region is not formed.

In the present embodiment, the ultraviolet rays 21 are irradiated from a direction inclined by about 21 ° from the normal line direction of the base member 1, but this angle can be changed according to the width of the electrode pattern.

Next, referring to FIGS. 5 (b) and 6 (b), with respect to the normal direction of the base member 1, a direction substantially mirror-symmetrical to the irradiation direction of the ultraviolet rays 21 in the first exposure step (opposite direction). Then, the second exposure step is performed by irradiating ultraviolet rays 21 'from the side).

As shown in FIG. 5B, IIIA-III
A photomask having no light-shielding pattern is used for the portion in the vicinity of the line A section, and the entire surface is irradiated with the ultraviolet ray 21 '. As a result, the shadows of all the walls are projected onto the opposing wall surfaces through the groove, and the upper region of about 200 μm of the side wall opposed to the side wall exposed in the first exposure step is exposed.

On the other hand, as shown in FIG. 6 (b), IIIB-
In a portion near the IIIB line cross section, a second photomask 19 having an opening in a portion thereof is used, and alignment is performed so that a part of the right side surface of the groove 4 is irradiated with the ultraviolet ray 21 ′. The slit pattern (gap pattern) 17, which will be described later, is exposed.

Here, it is desirable that the slit pattern 17 is formed at the upper end of the groove side surface as much as possible. This is when the drive signal is input to the inkjet head,
This is to prevent the deformation of the wall of the slit forming portion from giving noise to ink ejection, and to prevent the pattern from spreading due to the diffraction of the ultraviolet rays 21 'as the slit pattern forming portion is closer to the photomask.

In the present embodiment, the slit pattern 17
Although the arrangement position of is set on the wall surface on the right side, it may be on the wall surface on the left side. Further, the slit pattern 17 can be arranged at the top of the wall within a range in which the reliability of the connecting portion between the electrode of the flexible substrate 41 and the electrode of the nozzle plate, which will be described later, is ensured.

However, at this time, as shown in FIG. 7A, it is desirable that a part of the slit pattern 17 be on the side surface of the groove. This means that when all of the slit patterns 17 are arranged on the top of the wall as shown in FIG. 7B, the electrodes of the adjacent ink flow paths are present on the same top of the wall.
This is because when connecting to the electrode of the flexible substrate 41 with the above-mentioned anisotropic conductive adhesive or solder, there is a high risk of short-circuiting the electrodes of the adjacent ink flow paths via the electrode of the flexible substrate 41.

Further, by simultaneously performing the exposure process for forming the electrode pattern and the exposure process for forming the slit pattern 17, the processing process can be simplified.

Next, referring to FIGS. 5 (c) and 6 (c), a photoresist 20 is used with a photoresist developer.
The exposed portion of is removed to form a photoresist pattern including a slit pattern 17 forming pattern.

Next, referring to FIGS. 5D and 6D, the metal electrode film 12 exposed from the photoresist 20 is etched (wet type) using an aqueous solution containing nitric acid or an ammonium persulfate aqueous solution. Etching).

By etching the metal electrode film 12 using an aqueous solution of nitric acid, ammonium persulfate or the like, the etching becomes isotropic and even on a surface having a large unevenness such as the groove 4 on the base member 1. Therefore, the etching process can be performed uniformly. In addition, since the electrodes can be processed by a batch process by a wet etching method, it is possible to perform manufacturing with higher throughput than mechanical processing such as grinding and polishing.

By this step, the metal electrode film 12 remains on the lower halves on both sides of the groove 4 and on the bottom of the groove 4, and the metal electrode film 12 facing the other side of the groove 4 is formed on the bottom.
Is electrically connected via. As a result, the metal electrode films 13 facing each other through the groove 4 can be electrically connected without using a conductive member such as paste.
The reliability of the electrical connection between the metal electrodes 13 can be improved.

Next, referring to FIGS. 5 (e) and 6 (e), the photoresist 20 is removed with a solvent such as acetone or a resist stripper to obtain a metal electrode 13 as an electrode pattern.

As described above, since the electrode pattern is formed by photolithography in the present embodiment, the reproducibility of the electrode pattern is high, and the ejection characteristics of the ink jet head are stabilized.

Although Cu is used as the metal electrode film 12 in this embodiment, a metal soluble in an acid or an alkali such as Al or Ni, or an alloy containing these as the main components is also used. be able to.

Although the embodiments of the present invention have been described above, it should be considered that the embodiments disclosed this time are exemplifications in all points and not restrictive. The scope of the present invention is defined by the claims, and includes meanings equivalent to the claims and all modifications within the scope.

[0080]

According to the present invention, the reliability of electrical connection between the flexible substrate and the electrodes of the ink jet head is dramatically improved, and the yield is improved. Further, since the reproducibility of the electrode width is improved, the ejection characteristics of the inkjet heads between heads and between manufacturing lots are stable.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of an inkjet head according to the present invention.

FIG. 2 is a perspective view showing a configuration of a base member of the present invention.

3 (a) to (d) are IIIA of FIG. 1, respectively.
-IIIB-I sectional drawing for demonstrating a IIIA cross section
11B is a cross-sectional view for explaining the IIB cross-section, a cross-sectional view for explaining the arrangement positions of the slits for separating the electrodes, and a cross-sectional view for explaining the connection part of the flexible substrate and a part of the metal electrode formed on the upper surface of the side wall. is there.

FIG. 4 is a perspective view of the head of FIG. 1 when viewed from the opposite side.

5A to 5E are cross-sectional views illustrating a manufacturing process of a cross-sectional portion taken along line IIIA-IIIA of the inkjet head according to the second embodiment of the present invention.

6A to 6E are cross-sectional views illustrating a manufacturing process of a cross-sectional portion taken along line IIIB-IIIB of the inkjet head according to the second embodiment of the present invention.

7 (a) and 7 (b) are cross-sectional views for explaining an appropriate region of an arrangement position of a slit separating electrodes.

8A and 8B are perspective views showing a structure of an ink jet head using a general shearing mode.

9A to 9C are process diagrams illustrating a method of forming an electrode film of a conventional inkjet head.

[Explanation of symbols]

1 base member, 2, 3 cover member, 4 groove, 5 electrode (metal film), 6 insulating film, 7 polarization direction, 9 nozzle plate, 10 nozzle hole, 11 side wall (partition wall), 12 metal electrode film, 13 metal electrode , 14 top surface, 15 bottom part (bottom surface), 16 ink channel, 17 slit pattern, 18 first photomask, 19 second photomask, 20 positive photoresist, 22 resin, 26
Conductive member, 34 ink inflow hole, 35 end face, 41
Flexible substrate, 42 conductive pattern, 51 1st
Electrode film, 52 second electrode film, 53 first vapor deposition direction, 5
4 Second vapor deposition direction, 100 inkjet head.

Claims (9)

[Claims] 1. A substrate made of a piezoelectric material having a plurality of grooves, a first conductive film portion formed on a side surface of the groove, and a first conductive film portion formed on an upper surface of a partition between the grooves. And a second conductive film portion electrically connected to the inkjet head. 2. The ink jet head according to claim 1, wherein a gap for separating the second conductive film portions formed on the adjacent partition walls is provided on a side surface of the groove or an upper surface of the partition wall. 3. The first conductive film portion formed on side surfaces facing each other in the groove is electrically connected via a third conductive film portion formed on a bottom surface of the groove. The inkjet head according to claim 2. 4. The ink jet head according to claim 3, wherein the first conductive film portion and the third conductive film portion are integrally formed. 5. The first, second and third conductive film portions are formed by:
A metal film containing Al, Cu or Ni as a main component,
The inkjet head according to any one of claims 1 to 4. 6. A step of forming a conductive film so as to cover the grooves and partition walls of a substrate having a plurality of grooves and partition walls between the grooves and made of a piezoelectric material, and a step of applying a photoresist on the conductive film. And a step of selectively exposing the photoresist to form a photoresist pattern, and processing the conductive film using the photoresist pattern to selectively form a side surface of the groove and a partition wall. And a step of forming a gap for separating the conductive films formed on the adjacent partition walls while leaving the conductive film on. 7. The step of forming the photoresist pattern includes the step of forming the photoresist pattern by irradiating the photoresist with exposure light obliquely with respect to the normal direction of the substrate. A method for manufacturing the inkjet head described. 8. The photoresist pattern forming step comprises obliquely exposing the exposure light to the photoresist on the second portion while blocking the exposure light to the photoresist on the first portion of the substrate. A first exposure step of irradiating from a direction, and the photoresist on the first portion is selectively exposed from a direction symmetrical to an irradiation direction of the exposure light in the first exposure step with respect to a normal direction of the substrate. 7. A method for manufacturing an inkjet head according to claim 6, further comprising: a second exposure step of irradiating the photoresist on the second portion with irradiating the light. 9. The method for manufacturing an ink jet head according to claim 6, wherein the conductive film is processed by a wet etching method.