JPH11348276A - Ink-jet recording head and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a superior print quality by eliminating crosstalks and to form an ink-jet recording head in a high-density, compact-structure with many nozzles performing at high speed with a low power and reduced costs by improving an electromechanical conversion efficiency (transmission efficiency for a pressure to an ink in a pressure chamber). SOLUTION: In the ink-jet recording head, a plurality of piezoelectric elements 7a, 7b, 7c are separated from each other, each having an active area and an inactive area and fixed to a pressure chamber unit 25 at the inactive area. A notch part is formed to an inactive part to improve an electromechanical conversion efficiency. According to a manufacture for this ink-jet recording head, after a piezoelectric element block is united to the pressure chamber unit 25, the piezoelectric element block is cut thereby forming piezoelectric elements 7a, 7b, 7c corresponding to respective pressure chambers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head and a method of manufacturing the same, and more particularly to an ink jet recording head used in a printer, a facsimile, a copying machine, and the like, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, this type of ink jet recording head is disclosed in, for example, Japanese Patent Application Laid-Open No. 9-174837.

FIG. 13 is a sectional view of a conventional ink jet recording head.

In a conventional ink jet recording head, pressure chambers 2a, 2b, 2c filled with ink 1 are
The upper wall is composed of diaphragms 3a, 3b, 3c.
a, 3b, 3c are the piezoelectric elements 101a, 101b, 10
1c. Piezoelectric elements 101a, 1
01b and 101c are joined to and integrated with the base portion 102 on the surface opposite to the joint surface with the diaphragm.

FIG. 14 is a sectional view taken along the line DD of FIG.

The pressure chamber 2a communicates with the nozzle 4a and communicates with the ink pool 6 via the ink supply port 5a. The piezoelectric element 101a has an inactive area (an area in which no distortion occurs even when a drive voltage is applied to the electrode) 2
01a and 202a are fixed to a member constituting the pressure chamber 2a, and are connected to the diaphragm 3a at an active region (region where strain is generated) 203a. The same applies to the other pressure chambers 2b and 2c.

By selectively applying a voltage to the piezoelectric element during printing, the generated displacement of the piezoelectric element is transmitted to the pressure chamber via the diaphragm, and the ink in the pressure chamber is compressed.
Ink droplets can be ejected from the nozzle.

[0008]

In the conventional example of the above-described system in which the pressure chamber is compressed by the expansion and contraction operation of the piezoelectric element, each of the piezoelectric elements 101a, 101b and 101c is integrated by the base portion 102. , Each piezoelectric element 101
a, 101b and 101c are inactive areas 201a and 202
Although a is fixed to the pressure chambers 2a, 2b, and 2c at a, the displacement of the driving piezoelectric element causes the non-driven piezoelectric element to vibrate in the piezoelectric element displacement direction via the base portion 102, and is adjacent to the piezoelectric element. The crosstalk is transmitted to the non-driven pressure chamber and causes a problem. By crosstalk,
The greater the number of simultaneously driven nozzles (the number of piezoelectric elements), the smaller the droplet speed and droplet diameter of the ejected ink droplets. In other words, the droplet speed and the droplet diameter of the ejected ink droplets fluctuate depending on the number of nozzles (the number of piezoelectric elements) that are driven at the same time. As described above, the crosstalk causes a deterioration in print quality.

The piezoelectric element 101a is connected to the active region 20.
Since the inactive regions 201a and 202a are integrated on both sides of 3a, the displacement generated by the active region 203a is restricted by the inactive regions 201a and 202a, and the electromechanical conversion efficiency (the efficiency of transmitting pressure to the ink in the pressure chamber) is reduced. bad.

An object of the present invention is to improve the printing quality by eliminating crosstalk and improve the electromechanical conversion efficiency (efficiency of transmitting pressure to the ink in the pressure chamber) to increase the density and reduce the size. An object of the present invention is to provide an ink jet recording head capable of increasing the number of nozzles, increasing the speed, reducing power consumption, and reducing costs, and a method for manufacturing the same.

[0011]

According to the present invention, there is provided an ink jet recording head according to the present invention, wherein a plurality of pressure chambers each having one vibrating wall which is in communication with a nozzle and an ink supply port and vibrates in the same direction are provided. Pressure chamber unit including a chamber, 2
And a plurality of piezoelectric elements each having one external electrode and joined to the plurality of vibrating walls, wherein each of the plurality of piezoelectric elements has an activity in which a strain is generated internally when a voltage is applied between the external electrodes. Ink jets joined to the corresponding pressure chambers in an inactive area which is joined to the vibrating wall of the corresponding pressure chamber in each area and in which no distortion occurs inside even when a voltage is applied between the external electrodes. In the recording head, the inactive areas are joined only to the corresponding pressure chambers.

According to the present invention, the plurality of piezoelectric elements are joined only to the corresponding pressure chambers in the inactive region, and have no other means for fixing the positional relationship between the piezoelectric elements. Therefore, the displacement due to the driving piezoelectric element is not transmitted to the non-driven piezoelectric element, and the non-driven piezoelectric element does not vibrate in the displacement direction, and no crosstalk occurs.

[0013] The present invention described in claim 2 provides the present invention.
In addition to the configuration of 1, the piezoelectric element further includes a plurality of layers of piezoelectric materials and a plurality of layers of internal electrodes alternately stacked, and the internal electrodes are alternately layer by layer in one direction perpendicular to the stacking direction. However, a predetermined width is overlapped and stacked at a position shifted to two external electrodes provided on both side surfaces of the piezoelectric element in the shift direction of the internal electrode, and the piezoelectric element is connected to the internal electrode. Are joined to the vibrating wall in an active area that is stacked with the predetermined width in an overlapped manner.
An inactive region near one of the outer electrodes and in which every other layer of the inner electrode is stacked one on top of another, and joined to the pressure chamber.

According to the present invention, a sufficient displacement can be given to the vibrating wall even if the width in the direction perpendicular to the laminating direction is reduced.
Therefore, the pressure chambers can be arranged at a high density.

[0015] The present invention described in claim 3 provides the present invention.
In addition to the configuration of 1, the piezoelectric element further includes a piezoelectric material, a non-piezoelectric material joined to both sides of the piezoelectric material in a direction perpendicular to a row direction of the pressure chambers, and at least a part of the piezoelectric material. 2 facing in a direction parallel to the row direction of the pressure chambers
And two external electrodes formed on one surface, the piezoelectric element is joined to the vibration wall with the piezoelectric material, and joined to the pressure chamber with the non-piezoelectric materials on both sides of the piezoelectric material. ing.

According to the present invention, the pressure chambers can be arranged at a high density, and a low-cost ink jet recording head can be obtained because a single-layer piezoelectric element is used instead of an expensive laminated piezoelectric element.

The present invention described in claim 4 provides the present invention.
In addition to the configuration of 1, 2, or 3, the piezoelectric element further includes:
A cut portion is provided in an inactive region between a portion joined to the vibration wall and a portion joined to the pressure chamber.

According to the present invention, since the cut portion is provided between the portion joined to the vibration wall and the portion joined to the pressure chamber, the active area of the piezoelectric element is reduced. The generated displacement is hardly restricted, and the electromechanical conversion efficiency (pressure transmission efficiency to the ink in the pressure chamber) is good.

According to a sixth aspect of the present invention, there is provided a method of manufacturing an ink jet recording head according to the first or second aspect, wherein a plurality of pressure chambers are arranged in a row direction of the pressure chambers. 2 which is formed continuously over the entire length in the column direction.
A first step of forming a piezoelectric element block having two external electrodes, the active area and the inactive area, a second step of joining the piezoelectric element block to the pressure chamber unit, and joining to the pressure chamber unit Cutting the separated piezoelectric element block to form a plurality of piezoelectric elements respectively corresponding to the plurality of pressure chambers.

According to the present invention, since each piezoelectric element is formed separately after the piezoelectric element block and the pressure chamber unit are joined, the positioning accuracy of each pressure chamber and each piezoelectric element is good.

[0021]

FIG. 1 is a sectional view showing a first embodiment of an ink jet recording head according to the present invention. FIG. 2 is a sectional view taken along line AA of FIG.

In FIG. 1, pressure chambers 2a, 2b and 2c filled with ink 1 are easily deformed into a plate-like substrate member having a plurality of recesses of the same shape formed in a line at regular intervals. The plate-shaped diaphragm 3 is joined and formed. As shown in FIG. 2, the pressure chambers 2a, 2b, 2
c communicates with the nozzles 4a, 4b, 4c for ejecting ink droplets toward the print medium, and all communicates with the ink pool 6, which supplies the ink 1 via the ink supply ports 5a, 5b, 5c, respectively. .

The diaphragm 3 has completely separated piezoelectric elements 7a, 7a corresponding to the pressure chambers 2a, 2b, 2c.
b and 7c are joined.

The piezoelectric element 7a is a so-called laminated piezoelectric element, and has a plurality of internal electrodes alternately connected to two external electrodes 8a and 9a. External electrode 8
When a voltage is applied to the electrodes a and 9a, an electric field is applied to the active region 12a in which the internal electrodes connected to the respective external electrodes alternately overlap each other with the piezoelectric ceramic layer interposed therebetween, thereby causing distortion. In other areas, only the internal electrodes connected to one of the external electrodes exist with the piezoelectric ceramic layer interposed therebetween.
a, 9a, this region, the inactive region 10
Since no electric field is applied to a and 11a, the structure does not generate distortion. The piezoelectric element 7a is a piezoelectric element 7a
The lower surfaces of the inactive regions 10a and 11a are joined to a portion of the diaphragm 3 fixed to the substrate member, and the piezoelectric elements 7a
The lower surface of the active region 12a is connected to the projection 3a corresponding to the pressure chamber 2a of the diaphragm 3.

The same applies to the other piezoelectric elements 7b and 7c.

By selectively applying a voltage to the external electrodes of the piezoelectric element during printing, the piezoelectric element is displaced in the laminating direction of the internal electrodes, and the generated displacement of the piezoelectric element is transmitted to the pressure chamber via the diaphragm 3. Since the ink in the pressure chamber is compressed, an ink droplet can be ejected from the nozzle.

In the first embodiment of the present invention, the piezoelectric elements 7a, 7b, and 7c are provided on the vibration plate at portions joined to the substrate member at two places on the lower surface of the inactive region on both sides of the active region. And each piezoelectric element 7
Since a, 7b, and 7c are completely separated, vibration is directly transmitted to the non-driven piezoelectric element due to the generated displacement of the driven piezoelectric element, and the non-driven piezoelectric element vibrates in the displacement direction in which pressure is applied to the pressure chamber. There is nothing to do. Further, a force in a direction of bending is applied to the substrate member by the generated displacement of the driven piezoelectric element, and the substrate member vibrates, but due to the vibration in this direction, almost no pressure is generated in the non-driven pressure chamber, No crosstalk occurs.

Therefore, the drop speed and drop diameter of the ink droplets to be ejected do not vary depending on the number of nozzles (the number of piezoelectric elements) driven at the same time, stable ink droplets can be ejected, and ink jet recording with good print quality can be achieved. The head is obtained.

Next, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a sectional view showing a second embodiment of the ink jet recording head of the present invention. FIG.
FIG. 4 is a sectional view taken along line BB of FIG. 3.

The first embodiment is different from the first embodiment in that
The difference is that notches are provided in the inactive regions on both sides of the active regions a, 13b, and 13c.

As shown in FIG. 4, the piezoelectric element 13a has cutouts 17a and 18a in the inactive regions 14a and 15a on both sides of the active region 16a. Notch 17
The surface of the active region 16a on the side of the active region 16a
Are located at a predetermined distance from. Therefore, the laminated electrode is formed on the inner surfaces of the cut portions 17a and 18a.
Every other is exposed.

On the other side of the piezoelectric element 13a opposite to the side joined to the vibration plate 3, a non-laminated portion where no internal electrode is laminated occupies at least 20% of the thickness in the laminating direction. I have. The cut depth is preferably such that the thickness of the non-laminated portion is substantially left, that is, approximately equal to the thickness of the laminated portion. This is wasteful because the displacement of the active region 16a is limited by the inactive regions 14a and 15a even if the internal electrodes are laminated, and the thickness is reduced if the internal electrode is laminated. This is because the cost can be reduced as compared with the case of using a laminated structure. Further, it is desirable that the corners of the cuts 17a and 18a have curved surfaces with an appropriate curvature to avoid stress concentration.

Intermediate electrodes 19a and 20a are formed on substantially the entire inner surfaces of the cut portions 17a and 18a by plating or sputtering, and connect a plurality of internal electrodes in an inactive region to each other. Piezoelectric element 13a
External electrodes 21a and 22a are provided on both end surfaces of the intermediate electrode 1.
It is formed by plating or sputtering similarly to 9a and 20a. The internal electrodes of the active region 16a of the piezoelectric element 13a are alternately connected to the intermediate electrodes 19a and 20a, and further connected to the external electrodes 21a and 22a via the internal electrodes of the inactive regions 14a and 15a. Therefore, when a voltage is applied to the external electrodes 21a and 22a, the internal electrodes and the intermediate electrodes 19 of the inactive regions 15a and 16a
A voltage is applied to the internal electrodes of the active region 16a of the piezoelectric element 13a via the electrodes a and 20a, and an electric field is applied to the active region 16a, but no electric field is applied to the inactive regions 14a and 15a.

The piezoelectric element 13a is connected to the active region 16a.
Are fixed to the diaphragm 3 at the lower surfaces of the inactive regions 14a and 15a separated by the notches 17a and 18a.
The fixed portion is a portion fixed to the substrate member forming the pressure chamber.

On the other hand, the active region 16a of the piezoelectric element is connected to the projection 3a corresponding to the pressure chamber 2a of the diaphragm. The same applies to the other piezoelectric elements 13b and 13c.

In the second embodiment of the present invention, not only the same effects as in the first embodiment described above can be obtained, but also
Since the cut portion is provided in the inactive region near the active region of the piezoelectric element, the displacement generated in the active region of the piezoelectric element is hardly restricted by the inactive region,
Electromechanical conversion efficiency (pressure transmission efficiency to pressure chamber ink)
Will be better.

Next, a method for manufacturing the ink jet recording head of the present invention will be described.

FIG. 5 is an exploded perspective view showing the manufacturing method of the first embodiment of the present invention shown in FIGS. 1 and 2.

The first pressure chamber plate 23 having a space serving as a pressure chamber is joined to the nozzle plate 4 in which the nozzles 4a, 4b, 4c are formed. The ink supply port plates 5 in which the portions to be pressure chambers are lined up in a line at regular intervals are joined,
Further, a second pressure chamber plate 24 having a space serving as a pressure chamber as a space is joined, and the diaphragms 3a, 3b, 3
The diaphragm module 3 on which c is formed is joined, and
Piezoelectric element block 7 on which two external electrodes 8 and 9 are formed
To join. The piezoelectric element block 7 has a structure in which all the internal electrodes alternately overlap with the piezoelectric ceramics at a predetermined width in the central portion between the pair of side surfaces, and alternately overlap with every other internal electrode near the side surfaces with two layers of piezoelectric ceramics therebetween. Internal electrodes and piezoelectric ceramic layers are alternately laminated, sintered and integrated, and two external electrodes 8 and 9 extending from both end surfaces to the upper surface are formed.

The nozzle plate 4 is manufactured by forming the nozzles 4a, 4b, 4c by pressing on a stainless steel plate or the like, or by forming the nozzles 4a, 4c by electroforming.
A nozzle plate 4 made of a nickel material having b and 4c is formed.

The first pressure chamber plate 23, the ink supply port plate 5, and the second pressure chamber plate 24 are formed by pressing a stainless steel plate or the like, or by photolithography using a photosensitive dry film. I do.

The vibrating plate 3 has a shape in which the periphery of the projections 3a, 3b, 3c to which the respective piezoelectric elements are joined is thinner than other portions. The diaphragm 3 is formed by nickel electroforming, or by half-etching a stainless plate or the like.

[0044] In the case of joining stainless steels, the respective joinings can be made by thermal diffusion joining or joining using an adhesive, and the joining of dry films can be made by heat fusion.

The bonding between the piezoelectric element block 7 and the diaphragm 3 is performed using an adhesive.

Thus, the pressure chamber unit 25 including the nozzle plate 4, the first pressure chamber plate 23, the ink supply port plate 5, the second pressure chamber plate 24, and the diaphragm module 3, and the piezoelectric element block 7 And join.

FIG. 6A is a perspective view showing a state where these are joined.

Next, from this state, the piezoelectric element block 7 is cut beyond the joint surface with the pressure chamber unit 25 until the diaphragm 3 is cut to a predetermined depth. At this time, based on the outer shape of the pressure chamber unit 25, the cutting position is determined so that the piezoelectric element is formed while being accurately aligned with each pressure chamber, and the piezoelectric element block 7 is cut. 2), the piezoelectric elements 7a, 7b, 7c are separately formed. The cutting of the piezoelectric element block 7 can be performed by a dicing saw or a wire saw.

According to the manufacturing method of the present invention, after the piezoelectric element block and the pressure chamber unit 25 are joined, each piezoelectric element is aligned with and separated from each pressure chamber, so that the positioning accuracy of each pressure chamber and each piezoelectric element is adjusted. Is good. Therefore, it is possible to obtain an ink jet recording head having less variation in characteristics for each pressure chamber.

Next, a manufacturing method according to a second embodiment of the present invention will be described.

The manufacturing method according to the second embodiment of the present invention is different from the manufacturing method according to the first embodiment in that a notch is formed in the piezoelectric element block 13 and then joined to the pressure chamber unit 25. Is the same as the method of manufacturing.

FIG. 7 is a view for explaining a method of manufacturing the piezoelectric element block 13 according to the second embodiment.

In FIG. 7, a piezoelectric element block 13 similar to that of the first embodiment is prepared (FIG. 7A). In the second embodiment, the piezoelectric element block 13 is configured as shown in FIG.
In the upper part of (a), 20% or more of the thickness in the laminating direction is formed so that the non-laminated part which is the part where the internal electrode is not laminated is occupied.

On the lower surface of the piezoelectric element block 13 opposite to the non-laminated portion, the internal electrodes and the piezoelectric ceramic layers are alternately laminated so that every other internal electrode overlaps with two piezoelectric ceramic layers therebetween. Cut portions 17 and 18 are provided in the inactive region portion by using a dicing saw or a wire saw (FIG. 7B). The cuts 17 and 18 are provided at a predetermined distance in the width direction of the active region, and are formed at a uniform depth over the entire length of the block. Here, the cut depth is formed so as to substantially leave the thickness of the non-laminated portion, that is, substantially equal to the thickness of the laminated portion.

Next, the intermediate electrodes 19 and 20 are formed on the inner surfaces of the cut portions 17 and 18 and the external electrodes 21 and 22 are formed on both end surfaces of the piezoelectric element block 13 by plating or sputtering (FIG. 7C). At this time, a portion where the external electrode and the internal electrode are not formed is masked with a resist or the like, and the masking member is peeled off after forming the electrode.

In this manner, the piezoelectric element block 13 as shown in FIG. 7C is manufactured, joined to the pressure chamber unit 25, and positioned and cut into each pressure chamber as in the first embodiment. To separate.

According to the manufacturing method of the present invention, the cut portion is provided in the inactive area near the active area of the piezoelectric element, whereby an ink jet recording head having good electromechanical conversion efficiency (efficiency of transmitting pressure to ink in the pressure chamber) can be obtained. In addition, it is possible to easily manufacture each pressure chamber and each piezoelectric element with high positioning accuracy.

Next, a third embodiment of the present invention will be described.

FIG. 8 is a perspective view showing a third embodiment of the ink jet recording head of the present invention. FIG.
FIG. 9 is a sectional view taken along line CC of FIG. 8.

The structure of the second embodiment is that the piezoelectric elements 26a, 26b and 26c are single-layer piezoelectric elements in which a pair of external electrodes facing each other in the column direction of the pressure chambers are formed. Is different.

The piezoelectric element 26a of this embodiment is a single-layer piezoelectric element, and as shown in FIG. 9, a non-piezoelectric material part 27 which is not deformed even when an electric field is applied to both sides of a piezoelectric material part 28. The piezoelectric material portion 28 becomes an active region and the non-piezoelectric material portion becomes an inactive region. The cut depth is determined by a balance between the fact that the displacement of the active region is limited by the inactive region and that the rigidity of the cut portion is reduced. Further, it is desirable that the corner of the cut portion has a curved surface with an appropriate curvature to avoid stress concentration, as in the second embodiment.

The piezoelectric element 26a has external electrodes 29 covering a pair of surfaces opposed to each other in the column direction of the pressure chambers so as to cover at least all or a part of the piezoelectric material portion 28.
a and 30a are formed by plating or sputtering. Pad portions 31a and 32a for connecting the respective external electrodes 29a and 30a to a drive circuit (not shown) are formed on the upper surface of the piezoelectric element 26a.

With this configuration, when a voltage is applied to the external electrodes 29a and 30a, the non-piezoelectric material portion 27 is not deformed even when a voltage is applied between the external electrodes. Deforms when a voltage is applied between the external electrodes, and applies pressure to the pressure chamber 2a.

As in the second embodiment, the piezoelectric element 26a is fixed to the vibration plate 3 on the lower surface of the active region and the inactive region separated by the cutouts 17a and 18a. , Which are fixed to a substrate member constituting the pressure chamber.

On the other hand, the active region 16a of the piezoelectric element is connected to the projection 3a corresponding to the pressure chamber 2a of the diaphragm.

The same applies to the other piezoelectric elements 26b and 26c.

In the third embodiment of the present invention, similar to the second embodiment, not only crosstalk does not occur but printing quality is good, and not only electromechanical conversion efficiency is good, but also an expensive laminated piezoelectric element is used. Thus, an ink jet recording head that can be manufactured at low cost without using the same is obtained.

Next, a manufacturing method according to the third embodiment will be described.

FIG. 10 is a perspective view showing a method for manufacturing a piezoelectric element block according to the third embodiment. FIG.
FIG. 1 is a perspective view illustrating a method for manufacturing an ink jet recording head according to a third embodiment.

In FIG. 10, a piezoelectric element block 26 formed by joining non-piezoelectric material portions 27 to a pair of side surfaces of a piezoelectric material portion 28 is prepared.
Cut portions 17 and 18 are provided on the lower surface of the inactive region made of the non-piezoelectric material portion 27 with a dicing saw or a wire saw, respectively (FIG. 10A).
The cuts 17 and 18 are provided at a predetermined distance from the active region, and the cuts 17 and 18 are formed at a uniform depth over the entire length of the block.

Next, a photosensitive resin layer 33 for forming a pattern to be used as a mask when forming external electrodes is formed on the entire upper surface and side surfaces of the piezoelectric element block 26 and the entire inner surfaces of the cutouts 17 and 18. (FIG. 10B).

Next, the piezoelectric element block 26 having the photosensitive resin layer 33 formed thereon is joined to the pressure chamber unit 25.

Then, a portion 36 of the photosensitive resin layer 33 where the pad portion of the external electrode is to be formed after the block is cut.
Exposure is performed by aligning with the pressure chamber so as to remove the unexposed portions (FIG. 11A). Then, it is aligned with each pressure chamber and cut and separated by a dicing saw or the like as in the first and second embodiments (FIG. 11).
(B)).

Then, an external electrode is formed on a portion not covered with the photosensitive resin layer 33 by plating or sputtering, and after forming the electrode, the photosensitive resin layer 33 is peeled off.

According to the manufacturing method of the present invention, since a single-layer piezoelectric element having a pair of counter electrodes is joined to each pressure chamber in the direction of the row of pressure chambers, the pressure chambers are arranged at high density. Therefore, it is possible to easily manufacture an ink jet recording head which not only has good electromechanical conversion efficiency but also can reduce the cost without using an expensive laminated piezoelectric element.

Next, a fourth embodiment of the present invention will be described.

FIG. 12 is a perspective view showing an ink jet recording head according to a fourth embodiment of the present invention.

In the present embodiment, similar to the configuration of the third embodiment described above, the piezoelectric elements 34a, 34b, and 34c are formed of a single layer in which a pair of external electrodes facing each other in the row direction of the pressure chambers is formed. Are different in that they have no cut.

The piezoelectric element 34a of the present embodiment is also a single-layer piezoelectric element, and is similar to the third embodiment in that a non-piezoelectric material part which does not deform even when an electric field is applied to both sides of the piezoelectric material part is joined. The piezoelectric material portion becomes an active region and the non-piezoelectric material portion becomes an inactive region.

Next, a method for manufacturing the ink jet recording head of the present embodiment will be described.

As in the third embodiment, a piezoelectric element block formed by joining non-piezoelectric material portions to a pair of side surfaces of a piezoelectric material portion is prepared.

Next, in this embodiment, a photosensitive resin layer for forming a pattern to be used as a mask when forming external electrodes is formed on the entire upper surface and side surfaces of the piezoelectric element block without providing a cut portion. Then, the piezoelectric element block on which the photosensitive resin layer is formed is joined to the pressure chamber unit 25.

Then, the photosensitive resin layer is exposed to light by aligning it with the pressure chamber so as to remove the portion where the pad portion of the external electrode is to be formed after the block is cut, and the non-exposed portion is removed.

Then, each of the pressure chambers is positioned and cut and separated by a dicing saw or the like as in the first, second and third embodiments.

Then, an external electrode is formed on a portion not covered with the photosensitive resin layer 33 by plating or sputtering, and after forming the electrode, the photosensitive resin layer 33 is peeled off.

According to the present embodiment, the step of forming the cut portion in the piezoelectric element block and the step of forming the photosensitive resin layer in the cut portion are unnecessary, so that the ink jet recording head can be easily manufactured at low cost. be able to.

The positional relationship among the pressure chambers, the nozzles, and the ink supply holes in the pressure chamber unit is not limited to this, and the pressure chambers are arranged in a line and the diaphragm is provided on the same surface. It does not matter if it is.

[0088]

According to the present invention, there is no crosstalk,
Superior printing quality and improved electromechanical conversion efficiency (pressure transmission efficiency to pressure chamber ink) enable high density, small size, multiple nozzles, high speed, low power, and low cost. As a result, a stable ink jet recording head with little variation and a method for manufacturing the same can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view showing a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is an exploded perspective view showing the manufacturing method according to the first embodiment of the present invention.

FIG. 6 is a perspective view illustrating a manufacturing method according to the first embodiment of the present invention. (A) is a perspective view of a state where the pressure chamber unit 25 and the piezoelectric element block 7 are joined. (B)
FIG. 3 is a perspective view of a state where a piezoelectric element block joined to a pressure chamber unit 25 is cut and separated.

FIG. 7 is a perspective view illustrating a method for manufacturing a piezoelectric element block according to a second embodiment of the present invention.

FIG. 8 is a perspective view showing a third embodiment of the present invention.

FIG. 9 is a sectional view taken along the line CC in FIG. 8;

FIG. 10 is a perspective view illustrating a method for manufacturing a piezoelectric element block according to a third embodiment of the present invention.

FIG. 11 is a perspective view illustrating a method for manufacturing an ink jet recording head according to a third embodiment of the present invention.

FIG. 12 is a perspective view showing a fourth embodiment of the present invention.

FIG. 13 is a sectional view showing a conventional example.

FIG. 14 is a sectional view taken along line DD of FIG. 13;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink 2a, 2b, 2c Pressure chamber 3a, 3b, 3c Vibrating plate 3 Vibrating plate module 4a, 4b, 4c Nozzle 4 Nozzle plate 5a, 5b, 5c Ink supply port 5 Ink supply plate 6 Ink pool 7a, 7b, 7c Piezoelectric element 7 Piezoelectric element block 8, 8a, 8b, 8c External electrode 9, 9a, 9b, 9c External electrode 10a, 10b, 10c Inactive area 11a, 11b, 11c Inactive area 12a, 12b, 12c Active area 13a, 13b , 13c Piezoelectric element 13 Piezoelectric element block 14a, 14b, 14c Inactive area 15a, 15b, 15c Inactive area 16a, 16b, 16c Active area 17, 17a, 17b, 17c Cut section 18, 18a, 18b, 18c Cut section 19 , 19a, 19b, 19c Intermediate electrodes 20, 20a, 0b, 20c Intermediate electrode 21, 21a, 21b, 21c External electrode 22, 22a, 22b, 22c External electrode 23 First pressure chamber plate 24 Second pressure chamber plate 25 Pressure chamber units 26a, 26b, 26c Piezoelectric element 26 Piezoelectric Element block 27 Non-piezoelectric material part 28 Piezoelectric material part 29a, 30a External electrode 31a, 32a Pad part 33 Photosensitive resin layer 34a, 34b, 34c Piezoelectric element 34 Piezoelectric element block 101a, 101b, 101c Piezoelectric element 102 Base part 201a, 202a Inactive area 203a Active area

Claims (9)

[Claims] 1. A pressure chamber unit including a plurality of pressure chambers each communicating with a nozzle and an ink supply port and having one vibrating wall vibrating in the same direction, and two external electrodes, respectively. A plurality of piezoelectric elements respectively joined to the vibrating wall, wherein each of the plurality of piezoelectric elements has a corresponding one of the pressure chambers in an active region in which an internal strain occurs when a voltage is applied between the external electrodes. In an ink jet recording head joined to the corresponding pressure chamber in an inactive region which is joined to the vibrating wall and in which no distortion occurs inside even when a voltage is applied between the external electrodes, the inactive region is An ink jet recording head which is joined only to each of the corresponding pressure chambers. 2. The piezoelectric element according to claim 1, wherein a plurality of piezoelectric material layers and a plurality of internal electrode layers are alternately laminated, and the internal electrodes are alternately shifted by one layer in one direction perpendicular to the laminating direction. However, a predetermined width is overlapped and stacked at the position, and the piezoelectric elements are alternately connected to two external electrodes provided on both side surfaces of the internal electrodes in the direction of displacement of the internal electrodes, and the piezoelectric elements are all of the internal electrodes. Are bonded to the vibrating wall in an active region that is stacked and stacked with the predetermined width, and in an inactive region near the two external electrodes and in which every other layer of the internal electrode is stacked and stacked. The ink jet recording head according to claim 1, wherein the ink jet recording head is joined to the pressure chamber. 3. The piezoelectric element is provided on at least a part of the piezoelectric material, a non-piezoelectric material joined to both sides of the piezoelectric material in a direction perpendicular to a row direction of the pressure chambers, and at least a part of the piezoelectric material. And two external electrodes formed on two surfaces facing each other in a direction parallel to the row direction of the pressure chambers. The piezoelectric element is joined to the vibration wall with the piezoelectric material,
The ink jet recording head according to claim 1, wherein the non-piezoelectric material on both sides of the piezoelectric material is joined to the pressure chamber. 4. The piezoelectric element according to claim 1, wherein the piezoelectric element has a cut portion between a portion joined to the vibration wall and a portion joined to the pressure chamber. 4. The inkjet recording head according to 2 or 3. 5. The piezoelectric element according to claim 1, wherein said piezoelectric element has a thickness of 20%
Having the above non-laminated portion, a cut portion that separates the entire thickness of the laminated portion of the piezoelectric element between a portion bonded to the vibration wall and a portion bonded to the pressure chamber. The inkjet recording head according to claim 2, wherein the inkjet recording head has: 6. The method for manufacturing an ink jet recording head according to claim 1, wherein the plurality of pressure chambers have a length in a column direction of the pressure chambers, and are continuous over the entire length in the column direction. A first step of forming a piezoelectric element block having two external electrodes formed as described above, the active area and the inactive area, and a second step of joining the piezoelectric element block to the pressure chamber unit. A third step of cutting and separating the piezoelectric element block joined to the pressure chamber unit to form a plurality of piezoelectric elements corresponding to the plurality of pressure chambers, respectively. Production method. 7. The method of manufacturing an ink jet recording head according to claim 3, wherein the piezoelectric material has a length corresponding to a plurality of pressure chambers in a row direction of the pressure chambers. A first step of forming a piezoelectric element block in which a non-piezoelectric material having the same length as that of the piezoelectric element block is joined; a second step of joining the piezoelectric element block to the pressure chamber unit; and a step of joining the pressure chamber unit. Cutting the piezoelectric element block to form a plurality of piezoelectric elements respectively corresponding to the plurality of pressure chambers. 8. The first step further comprises: a portion of the piezoelectric element block having a length corresponding to a plurality of pressure chambers joined to the vibration wall; and a portion joined to the pressure chamber. 8. The method according to claim 6, further comprising the step of forming a cut portion over the entire length of the block. 9. A method for manufacturing an ink jet recording head according to claim 3, wherein said two external electrodes have a pad portion extending to an upper surface of said piezoelectric element. A first step of forming a photosensitive resin layer on the entire top and side surfaces of a piezoelectric element block having a width of 2 mm, and a second step of joining the piezoelectric element block formed with the photosensitive resin layer to the pressure chamber unit And a third step of exposing the photosensitive resin layer to the pressure chamber and exposing the photosensitive resin layer to remove a portion of the photosensitive resin layer where the pad portion is to be formed after cutting the piezoelectric element block. A fourth step of cutting the piezoelectric element block joined to the pressure chamber unit to form a plurality of piezoelectric elements respectively corresponding to the plurality of pressure chambers; A fifth step of forming an external electrode having the pad portion on the cut surface of the element and the portion removed in the third step.