JP2014069483A - Ink jet head and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet head capable of normally discharging ink and a method of manufacturing the ink jet head.SOLUTION: An ink jet head includes a cavity unit 30 forming a pressure chamber 303. A separation layer 32 is laminated on the cavity unit 30. The separation layer 32 comes into contact with the pressure chamber 303. A piezoelectric actuator element 34 is disposed on the separation layer 32. The piezoelectric actuator element 34 has: a laminate 343 including piezoelectric layers 343A-343D; and a first external electrode 341 and a second external electrode 342 that are installed at ends of the laminate 343. The cavity unit 30 has first hole portions 301, 302. The first hole portions 301, 302 are arranged to oppose to a first projecting portion 341A of the first external electrode 341 and a second projecting portion 342A of the second external electrode 342.

Description

  The present invention relates to an inkjet head that ejects ink and a method of manufacturing the same.

  2. Description of the Related Art Conventionally, inkjet heads that eject ink and methods for manufacturing the same are known. For example, the inkjet head described in Patent Document 1 includes a flow path unit in which a plurality of plates are stacked, and a piezoelectric actuator that is overlapped and bonded to the flow path unit. The flow path unit forms a pressure chamber and a nozzle. The actuator includes several piezoelectric sheets stacked. A large number of common electrodes and individual electrodes are formed on the piezoelectric sheet so as to correspond to the pressure chambers. When a voltage is selectively applied to the individual electrodes to cause a potential difference with the common electrode, an electric field acts on the active portion of the piezoelectric sheet, causing distortion in the stacking direction. That is, the actuator operates. When the actuator operates, ink in the pressure chamber is ejected from the nozzle.

  Various forms of the inkjet head actuator are possible. For example, a configuration is possible in which each actuator is formed as a separate chip-type element, and the chip-type actuator is mounted on the upper side of the layered member disposed on the upper side of the pressure chamber. The chip-type actuator includes a laminate in which a plurality of piezoelectric layers that are layers of piezoelectric material are laminated. A common electrode and individual electrodes for operating the actuator by applying a voltage to the piezoelectric layer are provided inside the laminate. The common electrode is connected to an external electrode provided at one end of the laminate. The individual electrode is connected to an external electrode provided at the other end of the laminate. When a voltage is applied to the pair of external electrodes, the piezoelectric layer is deformed and the actuator operates. As a result, the layered member vibrates and ink is ejected.

JP 2012-106513 A

  However, the pair of external electrodes provided at the ends of the actuator laminate may be formed by dipping the laminate in a material liquid for forming the external electrode. In this case, since a material for forming the external electrode adheres around the stacked body, the pair of external electrodes may protrude outward from the stacked body. When the external electrode protrudes from the laminate, the actuator laminate may float from the layered member by the protruding external electrode, and a space may be formed between the actuator laminate and the layered member. Due to the effect of this space, the operation of the actuator becomes difficult to propagate to the layered member, and ink may not be ejected normally.

  An object of the present invention is to provide an ink jet head capable of normally ejecting ink and a method for manufacturing the same.

  An inkjet head according to a first aspect of the present invention is an inkjet head having a plurality of channels each including a plurality of nozzles that eject ink and an ink chamber that stores the ink ejected from the nozzle. An ink chamber forming member which is a member having a hole or a groove forming the ink chamber, a layered member stacked on the ink chamber forming member and in contact with the ink chamber, and a piezoelectric actuator element disposed on the layered member The actuator element includes a stacked body in which a plurality of piezoelectric layers are stacked, and a first internal electrode disposed between two adjacent piezoelectric layers of the stacked body and extending to a first end of the stacked body And between the two adjacent piezoelectric layers of the multilayer body, opposed to the first internal electrode with at least one piezoelectric layer interposed therebetween, A second internal electrode extending to a second end located at a position, and an electrode provided at the first end and connected to the first internal electrode, the first internal electrode protruding in the stacking direction of the stacked body A first external electrode having one protrusion and an electrode provided at the second end and connected to the second internal electrode, the second external electrode protruding in the stacking direction of the stacked body. And at least one of the ink forming member and the layered member has a first hole provided at a position facing the first projecting portion and the second projecting portion.

  The first protrusion of the first external electrode and the second protrusion of the second external electrode protrude outward in the stacking direction of the multilayer body of piezoelectric actuator elements. Since the first hole is provided at a position facing the first protrusion of the first external electrode and the second protrusion of the second external electrode, compared to the case where the first hole is not provided, The first protrusion of the first external electrode and the second protrusion of the second external electrode can be further arranged on the ink chamber forming member side. Therefore, the laminated body of piezoelectric actuator elements comes closer to the layered member. For this reason, the operation of the piezoelectric actuator element easily propagates to the layered member, and ink can be ejected normally.

  In the inkjet head, the first hole portion may be formed in the ink chamber forming member, and the first hole portion formed in the ink chamber forming member may be covered with the layered member. In this case, the first hole is not formed in the layered member stacked in the first hole, and the first hole formed in the ink chamber forming member is covered with the layered member. For this reason, it is possible to prevent ink from leaking from the first hole.

  In the ink jet head, the layered member has conductivity, and the first external electrodes of the piezoelectric actuator elements of the respective channels are electrically connected to each other via the layered member, and the second external electrode And the layered member may be insulated by an insulating layer laminated on the layered member. In this case, a layered member can be used as a common wiring for connecting the first external electrodes of the piezoelectric actuator element. For this reason, it is not necessary to provide wiring separately. Therefore, the manufacturing cost of the inkjet head can be reduced.

  The inkjet head includes a wiring member provided with a bump connected to the second external electrode, and the insulating layer extends over the layered member, and a plurality of the insulating layers are stacked on the layered member. Each of the piezoelectric actuator elements may be arranged so that the second external electrodes of the two rows of the piezoelectric actuator elements face each other. For example, when the conductive connection material that electrically connects the second external electrode and the electrode of the flexible printed wiring that connects the piezoelectric actuator element to the external device collapses from the second external electrode during manufacturing, the connection material Falls on the insulating layer. For this reason, it is possible to prevent the second external electrode and the layered member from being short-circuited via the conductive connection material.

  In the ink jet head, the layered member does not have conductivity, and the first external electrodes of the actuator elements of the respective channels are electrically connected to each other via wiring formed on the layered member. Also good. In this case, it is not necessary to provide wiring for connecting the first external electrodes to the flexible printed wiring or the like. This eliminates the need for a conductive connection material for connecting the first external electrode and the flexible printed wiring, and can reduce the manufacturing cost of the inkjet head.

  In the ink jet head, the layered member has conductivity, the first external electrode is electrically connected to the layered member, and the second external electrode is provided in the first hole provided in the layered member. The portion may be insulated from the layered member. In this case, since the second external electrode and the layered member are separated by the first hole provided in the layered member, the second external electrode and the layered member can be reliably insulated.

  In the ink jet head, the first hole portion facing the second projecting portion of the second external electrode may be filled with an elastic member having an insulating property. In this case, since the first hole facing the second external electrode is filled with the insulating member, the second external electrode and the layered member can be more reliably insulated. In addition, since the member filling the first hole portion has elasticity, when the piezoelectric actuator element is arranged, the second protruding portion protruding from the laminate of the piezoelectric actuator elements is buried in the elastic member, and the piezoelectric actuator element The laminate approaches the layered member. For this reason, the operation of the piezoelectric actuator element easily propagates to the layered member, and ink can be ejected normally.

  In the ink jet head, the layered member is provided on the ink chamber side from the first hole so as to face the first hole in a direction in which the first external electrode and the second external electrode face each other. At least one groove portion may be provided. In this case, when the laminated body of piezoelectric actuator elements and the layered member are bonded with an adhesive, excess adhesive enters the groove. For this reason, the laminated body of piezoelectric actuator elements and the layered member are closer to each other than when excess adhesive remains between the laminated body of piezoelectric actuator elements and the layered member. Therefore, the operation of the piezoelectric actuator element is more easily propagated to the layered member, and ink can be ejected normally.

  In the inkjet head, the first protrusion and the second protrusion that protrude in the stacking direction from the stacked body may be positioned by the first hole. In this case, since the first projecting portion and the second projecting portion are positioned by the first hole portion, variation in the arrangement position of the piezoelectric actuator elements is reduced as compared with the case where the first projecting portion is not positioned by the first hole portion. Therefore, the piezoelectric actuator element is disposed at a normal position, and ink can be discharged normally.

  An inkjet head manufacturing method according to a second aspect of the present invention is an inkjet head having a plurality of channels each including a plurality of nozzles that eject ink and ink chambers that store the ink ejected from the nozzles. An ink chamber forming member forming step for forming an ink chamber forming member, which is a member having a hole or a groove for forming the ink chamber, and the ink chamber forming formed by the ink chamber forming member forming step. A first hole forming step for forming a pair of first holes in at least one of the member and the layered member disposed on the ink chamber forming member; and the ink chamber forming member is in contact with the ink chamber A layered member laminating step of laminating the layered member; and an actuator disposing step of disposing a piezoelectric actuator element on the layered member. The tutor element includes a laminate in which a plurality of piezoelectric layers are laminated, a first internal electrode disposed between two adjacent piezoelectric layers of the laminate, and extending to a first end of the laminate, and at least one A second end portion opposed to the first internal electrode across two piezoelectric layers and disposed between two adjacent piezoelectric layers of the multilayer body and located at a position different from the first end portion of the multilayer body A second internal electrode extending to the first end electrode, the first external electrode provided at the first end and connected to the first internal electrode, the first external electrode protruding in the stacking direction of the stacked body And a second external electrode provided at the second end portion and connected to the second internal electrode, the second external electrode having a second protruding portion protruding in the stacking direction of the stacked body, The actuator arranging step includes the first projecting portion and the second projecting portion. There arranging the piezoelectric actuator element in a position facing the first hole.

  In the piezoelectric actuator element manufactured by this manufacturing method, the first hole is provided at a position facing the first protrusion of the first external electrode and the second protrusion of the second external electrode. Compared to the case where no hole is provided, the first protrusion of the first external electrode and the second protrusion of the second external electrode can be arranged closer to the ink chamber forming member. Therefore, the laminated body of piezoelectric actuator elements comes closer to the layered member. For this reason, the operation of the piezoelectric actuator element easily propagates to the layered member, and ink can be ejected normally.

  In the method of manufacturing an inkjet head, the first hole forming step forms the first hole in the ink chamber forming member, and the layered member stacking step includes the first hole formed in the ink chamber forming member. The layered member may be laminated so as to cover one hole. In this case, the piezoelectric actuator element can prevent ink from leaking from the first hole.

  The inkjet head manufacturing method includes an insulating layer forming step of forming an insulating layer on the layered member stacked by the layered member stacking step, and the layered member stacked by the layered member stacking step has conductivity. And the actuator placement step electrically connects the first external electrode of the piezoelectric actuator element of each channel to the layered member, and on the insulation layer formed by the insulation layer formation step. A second external electrode may be arranged. In this case, a layered member can be used as a common wiring for connecting the first external electrodes of the piezoelectric actuator element. For this reason, it is not necessary to provide wiring separately. Therefore, the manufacturing cost of the inkjet head can be reduced.

  In the method for manufacturing an ink jet head, the insulating layer forming step forms a plurality of the insulating layers so as to extend on the layered member, and the actuator arranging step includes the second external of the actuator elements in two rows. The actuator element may be arranged on each of the plurality of insulating layers formed by the insulating layer forming step so that the electrodes face each other. In this case, for example, when the conductive connection material collapses from the second external electrode during manufacturing, the connection material falls on the insulating layer. For this reason, it is possible to prevent the second external electrode and the layered member from being short-circuited via the conductive connection material.

  The manufacturing method of the inkjet head includes a wiring forming step of forming a wiring on the layered member, and the actuator arranging step includes forming the first external electrode of the actuator element of each channel by the wiring forming step. The layered member does not have to be electrically connected. In this case, a conductive connection material for connecting the first external electrode and the flexible printed wiring or the like is not necessary, and the manufacturing cost of the inkjet head can be reduced.

  In the inkjet head manufacturing method, the first hole forming step forms at least the first hole in the layered member, and the actuator arranging step electrically connects the first external electrode to the layered member. The second external electrode may be connected to the first hole formed in the layered member, and the layered member may have conductivity. In this case, since the second external electrode and the layered member are separated by the first hole provided in the layered member, the second external electrode and the layered member can be reliably insulated.

  The method for manufacturing the inkjet head may include an embedding step of filling the first hole portion facing the second projecting portion of the second external electrode with an insulating elastic member. In this case, since the 1st hole part facing the 2nd protrusion part of a 2nd external electrode is filled with the member which has insulation, a 2nd external electrode and a layered member can be insulated further more reliably. In addition, since the member filling the first hole portion has elasticity, when the piezoelectric actuator element is arranged, the second protruding portion protruding from the laminate of the piezoelectric actuator elements is buried in the elastic member, and the piezoelectric actuator element The laminate approaches the layered member. For this reason, the operation of the piezoelectric actuator element easily propagates to the layered member, and ink can be ejected normally.

  The method for manufacturing the ink-jet head includes at least the first external electrode and the second external electrode facing each other in the direction corresponding to the first external electrode, and provided at least on the ink chamber side from the first external hole. You may provide the groove part formation process which forms one groove part in the said layered member. In this case, when the laminated body of piezoelectric actuator elements and the layered member are bonded with an adhesive, excess adhesive enters the groove. For this reason, the laminated body of piezoelectric actuator elements and the layered member are closer to each other than when excess adhesive remains between the laminated body of piezoelectric actuator elements and the layered member. Therefore, the operation of the piezoelectric actuator element is more easily propagated to the layered member, and ink can be ejected normally.

  In the method of manufacturing an inkjet head, when the actuator arranging step arranges the piezoelectric actuator element, the first projecting portion and the second projecting portion projecting in the stacking direction from the stacked body are the first projecting portion and the second projecting portion. It may be positioned by the hole. In this case, as compared with the case where the first protrusion and the second protrusion are not positioned in the first hole, variations in the arrangement position of the piezoelectric actuator elements are reduced. Therefore, the piezoelectric actuator element is disposed at a normal position, and ink can be ejected normally.

  In the ink jet head manufacturing method, the actuator arranging step includes a plurality of second holes provided at positions corresponding to the ink chambers of the ink chamber forming member formed by the ink chamber forming member forming step. A first disposing step of disposing the piezoelectric actuator element in the second hole of the first plate member; and the piezoelectric actuator element disposed in the second hole of the first plate member by the first disposing step. An adhesion step for adhering the second actuator to the second plate member, and a second arrangement step for arranging the piezoelectric actuator element adhered to the second plate member by the adhesion step on the ink chamber. . In this case, since a plurality of piezoelectric actuator elements can be arranged at a time, the arrangement time can be shortened as compared with the case where the piezoelectric actuator elements are mounted by a mounting machine.

2 is a perspective view of an internal structure of the printer 1. FIG. 2 is a plan view of the inkjet head 3. FIG. FIG. 3 is a cross-sectional view of the channel 70 in the direction of arrows II in FIG. FIG. 3 is a diagram illustrating a connection mode between a control board 60 and the inkjet head 3. It is a flowchart of a manufacturing process. It is a flowchart of an actuator arrangement | positioning process. FIG. 4 is a diagram illustrating a manufacturing process of the inkjet head 3. FIG. 6 is a diagram showing a process of bonding a piezoelectric actuator element 34 to a second plate member 91. It is sectional drawing of the channel 70 which concerns on 2nd embodiment. It is sectional drawing of the channel 70 which concerns on 3rd embodiment. It is sectional drawing of the channel 70 which concerns on 4th embodiment. It is sectional drawing of the channel 70 which concerns on 5th embodiment. It is sectional drawing which shows the state by which the elastic member 73 and the elastic member 74 were embedded. It is sectional drawing of the channel 70 which concerns on 6th embodiment. It is sectional drawing of the channel 70 which concerns on 7th embodiment.

  DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described with reference to the drawings. A first embodiment of the present invention will be described. First, the schematic structure of the printer 1 will be described with reference to FIG. The printer 1 is an ink jet printer including a carriage 2, an ink jet head 3, a transport roller 4, and the like. The carriage 2 reciprocates in the scanning direction (left and right direction in FIG. 1). An ink jet head 3 capable of ejecting ink is attached to the lower surface of the carriage 2. The transport roller 4 transports the recording paper P in the paper feed direction (front side in FIG. 1).

  The printer 1 is detachable from a cartridge (not shown) containing ink. Ink is supplied to the inkjet head 3 from a cartridge mounted on the printer 1. In the printer 1, the recording paper P is conveyed in the paper feeding direction by the conveying roller 4, and at the same time, the inkjet head 3 is reciprocated in the scanning direction by the carriage 2. At this time, an image, characters, or the like is recorded on the recording paper P by ejecting ink from the inkjet head 3. The recording paper P on which images, characters, etc. are recorded is discharged by the transport roller 4 in the paper feeding direction.

  The detailed structure of the inkjet head 3 is demonstrated with reference to FIGS. As shown in FIGS. 2 and 3, the ink jet head 3 includes a cavity unit 30, a piezoelectric actuator element 34, a separation layer 32, and a wiring board unit 50 (see FIGS. 3 and 4). The cavity unit 30 forms a nozzle 35 (see FIG. 2) that discharges ink and a pressure chamber 303 that stores the ink and supplies the stored ink to the nozzle 35. The separation layer 32 separates the ink in the pressure chamber 303 and the piezoelectric actuator element 34. The piezoelectric actuator element 34 vibrates the separation layer 32 and applies an ejection pressure to the ink in the pressure chamber 303. The wiring board unit 50 sends a signal from the control board 60 to the piezoelectric actuator element 34.

  The detailed structure of the cavity unit 30 will be described. As shown in FIG. 2, the cavity unit 30 includes four ink supply ports 38, four manifolds 39, a plurality of pressure chambers 303, a plurality of nozzles 35, and a plurality of throttle holes 40. The four ink supply ports 38 are respectively connected to four cartridges (not shown). Magenta, cyan, yellow, and black ink cartridges are connected in order from the ink supply port 38 belonging to the left side of FIG.

  The four manifolds 39 branch from the respective ink supply ports 38 and extend along the paper feed direction. The plurality of pressure chambers 303 communicate with the manifolds 39 through the throttle holes 40. The nozzle 35 communicates with each pressure chamber 303. The plurality of nozzles 35 and the plurality of pressure chambers 303 are arranged in the paper feeding direction to form a row of nozzles 35 and a row of pressure chambers 303. Eight rows of nozzles 35 and pressure chambers 303 are arranged in the scanning direction. In the following description, a configuration that can eject ink from the nozzle 35, including the nozzle 35 and the pressure chamber 303, is referred to as a “channel 70”.

  As shown in FIGS. 2 and 3, the cavity unit 30 includes a pair of first holes 301 and 302 outside the pressure chamber 303 (outside in the left-right direction in FIG. 2). As shown in FIG. 3, the pair of first holes 301 and 302 includes a first protrusion 341 </ b> A (described later) of the first external electrode 341 of the piezoelectric actuator element 34 and a second protrusion 342 </ b> A of the second external electrode 342. It is provided in the position which opposes each. The pair of first hole portions 301 and 302 are hole portions that are recessed downward from the first external electrode 341 and the second external electrode 342.

  The separation layer 32 is stacked on the cavity unit 30. A part of the separation layer 32 is in contact with the pressure chamber 303. The separation layer 32 is formed of a conductive member (for example, stainless steel). Upper portions of the first hole portions 301 and 302 of the separation layer 32 are concave portions 321 and 322 that are recessed downward toward the inside of the first hole portions 301 and 302.

  A piezoelectric actuator element 34 is disposed on the separation layer 32. As shown in FIG. 3, the piezoelectric actuator element 34 is a chip-type element including a rectangular laminated body 343. The stacked body 343 is located above the pressure chamber 303. The piezoelectric actuator element 34 includes a first external electrode 341 and a second external electrode 342. The first external electrode 341 is provided at the first end 347 on the left side of the multilayer body 343. The second external electrode 342 is provided at the second end 348 of the multilayer body 343. The second end 348 is located at a position different from the first end 347 (in the present embodiment, the right end of the stacked body 343). The first external electrode 341 and the second external electrode 342 are located above the first holes 301 and 302 of the cavity unit 30. The first external electrode 341 and the second external electrode 342 protrude outside the multilayer body 343 of the piezoelectric actuator element 34. For this reason, the first external electrode 341 includes first protrusions 341A and 341B that protrude in the stacking direction (vertical direction) of the stacked body 343. The second external electrode 342 includes second projecting portions 342A and 342B that project in the stacking direction of the stacked body 343. In addition, when the first external electrode 341 and the second external electrode 342 are formed on the laminated body 343 of the piezoelectric actuator element 34, the material for forming the first external electrode 341 and the second external electrode 342 is used. The laminate 343 is dipped into the liquid, and the material is attached around the laminate 343. For this reason, when the first external electrode 341 and the second external electrode 342 are formed, each of the first external electrode 341 and the second external electrode 342 protrudes outward from the stacked body 343. is there.

  The lower end portions (first projecting portion 341 </ b> A and second projecting portion 342 </ b> A) of each of the first external electrode 341 and the second external electrode 342 are located above the recesses 321 and 322 of the separation layer 32. Although details will be described later, when the inkjet head 3 is formed, the first protrusion 341A of the first external electrode 341 and the second protrusion 342B of the second external electrode 342 push the separation layer 32 downward to form the recess 321. , 322 are formed.

  The first external electrode 341 is electrically connected to the separation layer 32 having conductivity. For this reason, the first external electrodes 341 of the piezoelectric actuator elements 34 of the respective channels 70 are electrically connected to each other via the separation layer 32. An insulating layer 36 is disposed between the second external electrode 342 and the recess 322 of the separation layer 32. The second external electrode 342 and the separation layer 32 are insulated by the insulating layer 36.

  The stacked body 343 of the piezoelectric actuator elements 34 includes a plurality (four in this embodiment) of piezoelectric layers 343A to 343D stacked in the stacking direction (vertical direction). The piezoelectric layers 343A to 343D are stacked in the upward direction in order from the bottom. In addition, the multilayer body 343 of the piezoelectric actuator element 34 includes two first internal electrodes 344 and 345 and one second internal electrode 346. The piezoelectric layers 343A to 343D are formed of a soft magnetic material that is a piezoelectric material (for example, a piezoelectric material mainly composed of lead zirconate titanate that is a mixed crystal of lead titanate and lead zirconate).

  The first internal electrode 345 is disposed between two adjacent piezoelectric layers 343A and 343B. The first internal electrode 344 is disposed between two adjacent piezoelectric layers 343C and 343D. The first internal electrodes 344 and 345 extend to the first end 347 on the left side of the multilayer body 343. The first internal electrodes 344 and 345 are connected to the first external electrode 341 provided at the first end 347.

The second internal electrode 346 is disposed between the two adjacent piezoelectric layers 343B and 343C. The second internal electrode 346 faces the first internal electrode 345 through the piezoelectric layer 343B. The second internal electrode 346 is opposed to the first internal electrode 344 with the piezoelectric layer 343C interposed therebetween. The second internal electrode 346 extends to the second end 348 of the multilayer body 343. The second internal electrode 346 is connected to the second external electrode 342 provided at the second end 348. Piezoelectric layers 343B and 343C between the first internal electrodes 344 and 345 and the second internal electrode 346 are polarized in a direction from the second internal electrode 346 toward the first internal electrodes 344 and 345 (arrows in FIG. 3). 200 and arrow 201).

  On the upper side of the piezoelectric actuator element 34, a flexible wiring board 52 (Chip On Film: hereinafter, COF 52) of the wiring board unit 50 (see FIGS. 3 and 4) is disposed. As shown in FIG. 4, a driver IC 53 is mounted on the COF 52. The driver IC 53 is connected to the control unit 61 of the control board 60 via a flexible printed circuit board 51 connected to the COF 52. As shown in FIG. 3, the plurality of bumps 522 that are the electrodes of the COF 52 are connected to the second external electrode 342 of each channel 70. Further, the bumps 521 that are the electrodes of the COF 52 are connected to the separation layer 32. That is, the bump 521 of the COF 52 is connected to the first external electrode 341 through the separation layer 32. The bumps 521 and 522 are connected to the driver IC.

  The operation of the inkjet head 3 will be described. The controller 61 controls the driver IC 53 and controls the piezoelectric actuator element 34 of each channel 70 to vibrate the separation layer and eject ink. The voltage of the bump 521 of the COF 52 is always held at the ground level. That is, the first external electrode 341 and the first internal electrodes 344 and 345 that are electrically connected to the bumps 521 through the separation layer 32 are always held at the ground level. Further, the control unit 61 applies a drive signal for driving the piezoelectric actuator element 34 to the bump 522 via the driver IC 53. That is, a drive signal is applied to the second external electrode 342 and the second internal electrode 346 that are electrically connected to the bump 522. Thus, the first external electrode 341 and the first internal electrodes 344 and 345 of each channel 70 are held at the ground level in common. Each of the first external electrode 341 and the first internal electrodes 344 and 345 is also referred to as a common electrode. A drive signal is individually applied to the second external electrode 342 and the second internal electrode 346 of each channel 70. Each of the second external electrode 342 and the second internal electrode 346 is also referred to as an individual electrode.

  As described above, the piezoelectric layers 343B and 343C between the first internal electrodes 344 and 345 and the second internal electrode 346 are polarized. Therefore, when a drive signal is applied to the second internal electrode 346, the piezoelectric layers 343B and 343C contract toward the inner side in the left-right direction (see arrow 203). When the piezoelectric layers 343B and 343C contract inward in the left-right direction, the lower end of the multilayer body 343 and the separation layer 32 are bent so as to protrude downward. When the separation layer 32 is bent, pressure is applied to the ink in the pressure chamber 303, and the ink is ejected to the outside via the nozzle 35 (see FIG. 2).

  The arrangement of the piezoelectric actuator element 34 will be described in more detail. As shown in FIG. 2, a plurality of insulating layers 36 are stacked on the separation layer 32. The insulating layer 36 extends in the paper feeding direction on the separation layer 32. Two rows of piezoelectric actuator elements 34 are arranged on each of the plurality of insulating layers 36. The second external electrodes 342 of the two rows of piezoelectric actuator elements 34 face each other.

  The manufacturing process of the inkjet head 3 will be described with reference to FIGS. As shown in FIG. 5, in the manufacturing process of the inkjet head 3, a cavity unit forming process is first performed (S1). In the cavity unit forming step, for example, a plurality of silicon (Si) substrates are processed by etching or the like, and the processed plurality of silicon substrates are stacked. As a result, as shown in FIG. 7A, the cavity unit 30 in which the four ink supply ports 38, the four manifolds 39, the plurality of pressure chambers 303, the plurality of nozzles 35, and the plurality of throttle holes 40 are formed. It is formed. In FIG. 7A, only the periphery of the pressure chamber 303 formed in a groove shape or a hole shape is illustrated.

  Next, a first hole forming process is performed (S2). In the first hole forming step, as shown in FIG. 7B, a pair of first holes 301 and 302 are formed outside the pressure chamber 303 of the cavity unit 30 by, for example, half etching.

  Next, a separation layer stacking step is performed (S3). In the separation layer laminating step, one separation layer 32 formed in a layer shape (plate shape) in advance is laminated (arranged) on the upper side of the cavity unit 30. The separation layer 32 is laminated on the upper side of the cavity unit 30 with, for example, an adhesive. As a result, the separation layer 32 comes into contact with the pressure chamber 303 as shown in FIG.

  Next, an insulating layer forming step is performed (S4). In the insulating layer formation step, as shown in FIG. 7D, the insulating layer 36 is formed on the separation layer 32 laminated in the separation layer lamination step (S3). The insulating layer 36 is formed by, for example, applying a resist layer on the separation layer 32 by screen printing, ink jet, or the like and heating the resist layer to thermally cure. In the present embodiment, as shown in FIG. 2, a plurality of (four in this embodiment) insulating layers 36 are formed so as to extend on the separation layer 32 in the cloth feeding direction.

  Next, an actuator placement step is performed (S5). In the actuator arranging step, the piezoelectric actuator element 34 is placed on the separation layer 32, and the first projecting portion 341A of the first external electrode 341 and the second projecting portion 342A of the second external electrode 342 are opposed to the first holes 301 and 302. It is the process of arrange | positioning.

  The details of the actuator placement step will be described with reference to FIG. As shown in FIG. 6, in the actuator placement step, first, the first placement step is performed (S51). As shown in FIG. 8A, in the first arrangement process, the piezoelectric actuator elements 34 are arranged in the plurality of second holes 901 of the first plate member 90. The first plate member 90 is a plate member having a rectangular shape in plan view. The second hole 901 of the first plate-like member 90 is provided corresponding to the arrangement of the piezoelectric actuator elements 34 arranged in the inkjet head 3 (see FIG. 2). In the first arrangement step, a plurality of piezoelectric actuator elements 34 are supplied on the first plate-like member 90. Then, the first plate member 90 is vibrated and the piezoelectric actuator element 34 is disposed in the second hole 901. At this time, the upper surface of the piezoelectric actuator element 34 protrudes upward from the upper surface of the first plate member 90 (see FIG. 8A).

  Next, an adhesion process is performed (S52). In the bonding step, the piezoelectric actuator element 34 disposed in the second hole 901 of the first plate member 90 is bonded to the second plate member 91. An adhesive is applied to the bottom surface of the second plate-shaped member 91. When the piezoelectric actuator element 34 is bonded to the second plate-shaped member 91, the bottom surface of the second plate-shaped member 91 is brought into contact with the upper surface of the piezoelectric actuator element 34 (see FIG. 8B). Then, the second plate member 91 is lifted upward in a state where the piezoelectric actuator element 34 is bonded to the bottom surface of the second plate member 91 (see FIG. 8C).

  Next, a conductive adhesive application step is performed (S53). In the conductive adhesive application step, first, a conductive adhesive is applied on the separation layer 32 other than the portion where the insulating layer 36 is disposed. Application of the adhesive is performed, for example, by screen printing.

  Next, a second arrangement step is performed (S54). In the second arrangement step, the piezoelectric actuator element 34 (see FIG. 8C) bonded to the second plate-shaped member 91 in the bonding step (S52) is arranged on the separation layer 32 and above the pressure chamber 303. The second plate member 91 is pressed downward. At this time, the first external electrode 341 and the second external electrode 342 are disposed above the first holes 301 and 302. The first protrusion 341A of the first external electrode 341 of the piezoelectric actuator element 34 and the second protrusion 342B of the second external electrode 342 protrude outward from the stacked body 343. For this reason, when the piezoelectric actuator element 34 is disposed, the first protrusion 341A of the first external electrode 341 and the second protrusion 342A of the second external electrode 342 are separated above the first holes 301 and 302. The part of the layer 32 is pushed downward. Since the separation layer 32 has flexibility, the separation layer 32 pushed by the first projecting portion 341A of the first external electrode 341 and the second projecting portion 342A of the second external electrode 342 has the first hole 301, It dents downward toward the inside of 302. As a result, recesses 321 and 322 are formed (see FIG. 7E). The first protrusion 341A of the first external electrode 341 and the second protrusion 342A of the second external electrode 342 are positioned by the recesses 321 and 322 that are recessed by the shapes of the first holes 301 and 302. In other words, the first protrusion 341A of the first external electrode 341 and the second protrusion 342A of the second external electrode 342 are positioned by the first holes 301 and 302. As a result, as shown in FIG. 3, the piezoelectric actuator element 34 has a cavity on the separation layer 32 by the first holes 301 and 302 provided at positions facing the first protrusion 341A and the second protrusion 342A. The unit 30 and the separation layer 32 are bonded so as to be fitted.

  Then, the second plate member 91 is moved upward. The adhesive force of the adhesive on the bottom surface of the second plate-shaped member 91 is smaller than the adhesive force of the adhesive applied to the separation layer 32 in S53. Therefore, when the second plate-shaped member 91 moves upward, the piezoelectric actuator element 54 is peeled off from the second plate-shaped member 91 and bonded to the separation layer 32 side. When the heat treatment is performed in this state, the piezoelectric actuator element 34 is fixed by the adhesive applied in S53. In addition, the polarization directions of the piezoelectric layers 343B and 343C of the multilayer body 343 of the piezoelectric actuator element 34 are not determined.

  Next, the actuator placement step is completed, and a wiring connection step is performed (S6). In the wiring connection process, first, a conductive adhesive is applied to the upper portion of the second external electrode 342 to which the bump 522 is connected and the portion 328 of the separation layer 32 to which the bump 521 is connected. Bumps 521 and 522 are formed in advance on the COF 52. Then, the COF 52 is pushed from the upper side in a state where the bump 522 is disposed on the portion 328 and the bump 521 is disposed above the second external electrode 342. Thus, the bump 522 is bonded to the upper side of the second external electrode 342 via the conductive adhesive, and the bump 521 is bonded to the separation layer 32 (see FIG. 3). Thereby, a completed body (see FIG. 3) of the inkjet head 3 is obtained. The completed inkjet head 3 is connected to the control board 60, and the first internal electrodes 344 and 345 and the second internal electrodes 346 are controlled by the control board 60 through the first external electrode 341 and the second external electrode 342. When a voltage is applied between the piezoelectric layers 343B and 343C, the piezoelectric layers 343B and 343C are polarized. Next, the manufacturing process is finished.

  As described above, the ink jet head 3 of the present embodiment is manufactured. In the present embodiment, the first external electrode 341 and the second external electrode 342 protrude outside the stacked body 343 of the piezoelectric actuator element 34. If the first holes 301 and 302 are not provided, the recesses 321 and 322 of the separation layer 32 are not formed. Therefore, when the piezoelectric actuator element 34 is disposed on the upper side of the separation layer 32, the stacked body 343 is separated from the separation layer 32 by the thickness of the first external electrode 341 and the second external electrode 342. For this reason, the operation of the piezoelectric actuator element 34 is difficult to propagate to the separation layer 32. Therefore, there are cases where ink cannot be ejected normally.

  In the present embodiment, the first holes 301 and 302 are provided at positions facing the first protrusion 341A of the first external electrode 341 and the second protrusion 342A of the second external electrode 342. For this reason, compared with the case where the 1st hole parts 301 and 302 are not provided, the 1st protrusion part 341A of the 1st external electrode 341 and the 2nd protrusion part 342A of the 2nd external electrode 342 are made into the cavity unit 30 side more. (Lower side). Therefore, the stacked body 343 of the piezoelectric actuator elements 34 approaches the separation layer 32. For this reason, the operation of the piezoelectric actuator element 34 easily propagates to the separation layer 32, and ink can be ejected normally.

  In the present embodiment, the first hole portions 301 and 302 are formed in the cavity unit 30, and the first hole portions 301 and 302 formed in the cavity unit 30 are covered with the separation layer 32. For this reason, even if the ink in the pressure chamber 303 leaks from between the cavity unit 30 and the separation layer 32 and reaches the first holes 301 and 302, the ink is separated from the first holes 301 and 302 by the separation layer 32. Ink can be prevented from leaking outside.

  Further, the separation layer 32 has conductivity, and the first external electrodes 341 of the piezoelectric actuator elements 34 of each channel 70 are electrically connected to each other through the separation layer 32. That is, the separation layer 32 can be used as a common wiring for connecting the first external electrodes 341 of the piezoelectric actuator element 34 to each other. Therefore, it is not necessary to separately provide wiring for connecting the first external electrodes 341 to each other. Therefore, the manufacturing cost of the inkjet head 3 can be reduced.

  Further, the piezoelectric actuator elements 34 are arranged on each of the plurality of insulating layers 36 so that the second external electrodes 342 of the two rows of piezoelectric actuator elements 34 face each other. For this reason, as shown in FIG. 2, the insulating layer 36 is always located on the direction side of the second external electrode 342 of the piezoelectric actuator element 34 in one row toward the other row. Therefore, when the conductive adhesive connecting the second external electrode 342 and the bump 522 applied in the conductive adhesive application step (S53 in FIG. 6) collapses from the second external electrode 342, the conductive adhesive The adhesive falls on the insulating layer 36. For this reason, it is possible to prevent the second external electrode 342 and the separation layer 32 from being short-circuited via the conductive adhesive.

  Further, the piezoelectric actuator element 34 arranged in the actuator arranging step (S5) is positioned by the first holes 301 and 302. For this reason, the variation in the arrangement position of the piezoelectric actuator element 34 is reduced as compared with the case where the first hole portions 301 and 302 are not positioned. Therefore, the piezoelectric actuator element 34 is disposed at a normal position. Therefore, ink can be ejected normally.

  Further, the plurality of piezoelectric actuator elements 34 are bonded to the second plate-shaped member 91, and the plurality of piezoelectric actuator elements 34 are arranged on the pressure chamber 303 (on the separation layer 32) in the second arrangement step (S4). . Since a plurality of piezoelectric actuator elements 34 are disposed on the separation layer 32 at a time, the time for disposing the piezoelectric actuator elements 34 is shortened compared to the case where the individual piezoelectric actuator elements 34 are sequentially disposed by, for example, a mounting machine. can do.

  In the above embodiment, the pressure chamber 303 corresponds to the “ink chamber” of the present invention. The cavity unit 30 corresponds to the “ink chamber forming member” of the present invention. The separation layer 32 corresponds to the “layered member” of the present invention. The COF 50 corresponds to the “wiring member” of the present invention. The bump 522 corresponds to the “bump” of the present invention. The cavity unit forming step (S1) corresponds to the “ink chamber forming step” of the present invention. The separation layer laminating step (S3) corresponds to the “layered member laminating step” of the present invention.

  In addition, this invention is not limited to said embodiment, A various change is possible. For example, the first plate-like member 90, the second plate-like member 91, and the like are used and the piezoelectric actuator element 34 is disposed. However, the present invention is not limited to this. For example, the piezoelectric actuator element 34 may be disposed on the separation layer 32 by a mounting machine for mounting components.

  In the present embodiment, as shown in FIG. 3, the first internal electrodes 344 and 345 and the second internal electrode 346 are vertically symmetrical. The first external electrode 341 and the second external electrode 342 are also vertically symmetric. For this reason, for example, the piezoelectric actuator element 34 may be arranged on the separation layer 32 by turning upside down. Even in this case, the arrangement of the piezoelectric actuator elements 34 is the same as in the case of FIG. Therefore, ink can be ejected as in the above embodiment. In this case, the first holes 301 and 302 face the first protrusion 341B and the second protrusion 342B.

  Further, the piezoelectric actuator element 34 may be disposed on the separation layer 32 so as to be horizontally reversed. In this case, the second external electrode 342 is electrically connected to the separation layer 32, and the first external electrode 341 is connected to the bump 522. Therefore, one second internal electrode 346 connected to the second external electrode 342 is held at the ground level. A drive signal is applied to the first external electrode 341 and the two first internal electrodes 344 and 345. Further, after the wiring connection step (S6), the completed inkjet head 3 is connected to the control board 60, and the first internal electrode 344 is connected via the first external electrode 341 and the second external electrode 342 under the control of the control board 60. , 345 and the second internal electrode 346, the piezoelectric layers 343B and 343C are polarized. At this time, the polarization direction is opposite to the arrows 200 and 201. In this state, when the second external electrode 342 is held at the ground level and a drive signal is applied to the first external electrode 341, the piezoelectric layers 343B and 343C are moved inward in the left-right direction as in the case of the above embodiment. (See arrow 203). Therefore, ink can be ejected as in the above embodiment. In the case of this modification, the first external electrode 341 corresponds to the “second external electrode” of the present invention, and the second external electrode 342 corresponds to the “first external electrode” of the present invention. The first internal electrodes 344 and 345 correspond to the “second internal electrode” of the present invention, and the second internal electrode 346 corresponds to the “first internal electrode” of the present invention.

  Thus, the piezoelectric actuator element 34 of the present embodiment may be inverted vertically and horizontally. Therefore, when the piezoelectric actuator element 34 is disposed in the second hole portion 901 of the first plate-like member 90 in the first arrangement step (S51), the piezoelectric actuator element 34 may be inverted vertically and horizontally. Therefore, the process of arranging the piezoelectric actuator element 34 in the second hole 901 of the first plate-like member 90 can be simplified as compared with the case where the direction of the piezoelectric actuator element 34 needs to be aligned.

  Further, the number of the first internal electrodes 344 and 345 and the second internal electrodes 346 is not limited. For example, only one of the first internal electrodes 344 and 345 may be provided. Moreover, you may increase the number of a 1st internal electrode and a 2nd internal electrode.

  Moreover, in 1st embodiment, although the separation layer 32 had electroconductivity, it is not limited to this. For example, as in the second embodiment shown in FIG. 9, a separation layer 32A having no conductivity may be used. In this case, a wiring 72 that electrically connects the first external electrodes 341 of the piezoelectric actuator elements 34 of the respective channels 70 may be provided on the separation layer 32. The wiring forming process, which is a process for forming the wiring 72, is performed between the separation layer stacking process (S3) and the insulating layer forming process (S4) in FIG. 5 or between the insulating layer forming process (S4) and the actuator arranging process. (S5) may be performed. In the wiring formation step, the conductive wiring 72 is formed by, for example, sputtering or vapor deposition. The wiring 72 is also formed on the part 328, and the wiring 72 and the bump 521 are connected in the wiring connection step (S6).

  In the case of the second embodiment, it is not necessary to provide wiring for connecting the first external electrodes 341 to the COF 52 or the like. Therefore, a conductive adhesive is unnecessary as compared with the case where wiring for connecting the first external electrodes 341 is provided in the COF 52 and the wiring of the COF 52 and the first external electrode 341 are connected with a conductive adhesive. Therefore, the manufacturing cost of the inkjet head 3 can be reduced. The wiring 72 corresponds to the “wiring” of the present invention.

  In the first embodiment, the second external electrode 342 is insulated from the separation layer 32 by the insulating layer 36, but is not limited thereto. For example, as in the third embodiment shown in FIG. 10, the separation layer 32 is separated in a direction (downward) facing the second protrusion 342A of the second external electrode 342 and away from the second external electrode 342. A first hole 324 that penetrates the layer 32 may be provided. Then, the conductive separation layer 32 and the second external electrode 342 may be insulated by the first hole 324. In this case, the insulating layer forming step (S4) may not be performed. Moreover, you may provide the process of forming the 1st hole part 324 following a separated layer lamination process (S3). In addition to the manufacturing process shown in FIG. 5, a process of previously forming the first hole 324 in the separation layer 32 before being stacked in S3 may be provided. Then, the separation layer 32 in which the first hole 324 is formed in S3 may be laminated on the cavity unit 30.

  In the case of the third embodiment, the second external electrode 342 and the separation layer 32 are separated by the first hole 324 provided in the separation layer 32. Therefore, the second external electrode 342 and the separation layer 32 can be reliably insulated.

  Note that, as in the fourth embodiment shown in FIG. 11, the first hole 302 (see FIG. 10) may not be provided in the cavity unit 30, and the first hole 324 of the separation layer 32 may be provided. Even in this case, the second external electrode 342 and the separation layer 32 can be reliably insulated by the first hole 324.

  Further, as in the fifth embodiment shown in FIG. 12, the first holes 302 and 324 may be filled with an elastic member 74 having insulating properties (for example, epoxy resin or the like). In addition, a first hole 323 that faces the first protrusion 341A of the first external electrode 341 and penetrates the separation layer 32 in a direction away from the first external electrode 341 (downward) may be provided. And the 1st hole parts 301 and 323 may be filled up with the elastic member 73 (for example, conductive adhesive etc.) which has electroconductivity.

  In this case, for example, the first hole 323 is formed in the same manner as the case of forming the first hole 324 in the third embodiment (see FIG. 10). Further, the insulating layer forming step (S4) is not executed. In addition, before the actuator placement step (S5) is performed, the first embedding step of filling the first holes 301 and 323 with the elastic member 73 having conductivity, and the first with the elastic member 74 having no conductivity. A second embedding step of filling the holes 302 and 324 is performed. Through the first embedding step and the second embedding step, the first hole portions 301 and 323 are filled with the elastic member 73 and the first hole portions 302 and 324 are filled with the elastic member 74 as shown in FIG. It becomes a state. When the piezoelectric actuator element 34 is arranged in the second arrangement step (S54) of the actuator arrangement step (S5), the first protrusion 341A of the first external electrode 341 and the second protrusion of the second external electrode 342 are arranged. The elastic members 73 and 74 are bent downward by being pushed by 342B. As a result, as shown in FIG. 12, the first protrusion 341 </ b> A of the first external electrode 341 and the second protrusion 342 </ b> A of the second external electrode 342 are buried in the elastic members 73 and 74.

  In the case of the fifth embodiment, since the first hole portions 302 and 324 are filled with the elastic member 74 having insulating properties, the second external electrode 342 and the separation layer 32 can be further reliably insulated. In addition, since the elastic member 74 filling the first holes 302 and 324 has elasticity, the second protrusion 342A of the second external electrode 342 is buried in the elastic member 74 (see FIG. 12). For this reason, the stacked body 343 approaches the separation layer 32. Therefore, the operation of the piezoelectric actuator element 34 is easily propagated to the separation layer, and ink can be ejected normally.

  Further, since the first holes 301 and 323 are filled with the elastic member 73 having conductivity, the first external electrode 341 and the separation layer 32 can be electrically connected via the elastic member 73. Further, since the elastic member 73 filling the first hole portions 301 and 323 has elasticity, the first protruding portion 341A of the first external electrode 341 is buried in the elastic member 73 (see FIG. 12). For this reason, the stacked body 343 approaches the separation layer 32. Therefore, the operation of the piezoelectric actuator element 34 is easily propagated to the separation layer, and ink can be ejected normally. As in the case of the first hole 324 shown in FIG. 11, the first hole 301 may not be provided among the first holes 301 and 323. In this case, the elastic member 73 may be disposed in the first hole 323. As described above, the first hole portion only needs to be provided in at least one of the cavity unit 30 and the separation layer 32.

  Moreover, you may provide the groove parts 751 and 752 in the isolation | separation layer 32 like 6th embodiment shown in FIG. The groove 751 is provided on the pressure chamber 303 side of the first hole 301 so as to face the first hole 301 in the direction in which the first external electrode 341 and the second external electrode 342 face each other (the left-right direction in FIG. 14). It has been. The groove 752 is provided on the pressure chamber 303 side of the first hole 302 so as to face the first hole 302 in the direction in which the first external electrode 341 and the second external electrode 342 face each other. The groove portions 751 and 752 are located above the end portion of the pressure chamber 303. Further, the width of the groove portions 751 and 752 in the paper feeding direction (see FIG. 2) is substantially the same as that of the first external electrode 341 and the second external electrode.

  In the case of the sixth embodiment, a groove part forming process for forming the groove parts 751 and 752 is performed after the separation layer stacking process (S3). In the groove portion forming step, for example, the groove portions 751 and 752 are formed by half etching.

  The stacked body 343 of the piezoelectric actuator element 34 and the separation layer 32 are bonded by the conductive adhesive applied in S53. In the sixth embodiment, since the groove portions 751 and 752 are provided, when the stacked body 343 and the separation layer 32 are bonded, excess conductive adhesive enters the groove portions 751 and 752. For this reason, the laminated body 343 and the separation layer 32 come closer as compared with the case where excess adhesive remains between the laminated body 343 of the piezoelectric actuator element 34 and the separation layer 32. Therefore, the operation of the piezoelectric actuator element 34 is more easily propagated to the separation layer 32, and ink can be ejected normally.

  Further, the portion of the separation layer 32 where the groove portions 751 and 752 are provided is thinner than the portion where the groove portions 751 and 752 are not provided. For this reason, the separation layer 32 is easily bent in the groove portions 751 and 752. Therefore, the separation layer 32 is easily vibrated, and ink can be ejected more normally.

  When the separation layer 32 vibrates, the vibration of the separation layer 32 on the upper side of the pressure chamber 303 may propagate to the adjacent channel 70 via the separation layer 32, the elastic member 73, the elastic member 74, and the like ( So-called crosstalk). As described above, the separation layer 32 is easily bent in the groove portions 751 and 752. When the separation layer 32 is easy to bend, it is easier to reduce vibration propagating toward the adjacent channel 70 than when the separation layer 32 is difficult to bend. Therefore, it is possible to prevent vibration from propagating to the adjacent channel 70.

  In the sixth embodiment, the two groove portions 751 and 752 are provided, but the present invention is not limited to this. For example, at least one of the groove portions 751 and 752 may be provided. Further, the elastic member 73 having conductivity often includes a metal or the like. For this reason, the elastic member 73 having conductivity may be harder than the elastic member 74 having no conductivity. For this reason, the vibration of the separation layer 32 easily propagates through the elastic member 73 that is harder than the elastic member 74. Therefore, only the groove 751 on the side where the elastic member 74 that easily propagates the vibration is provided may be provided to prevent the vibration from propagating to the adjacent channel 70.

  Further, the bump 522 of the COF 52 and the second external electrode 342 are connected, and the bump 521 and the first external electrode 341 are connected via the separation layer 32 (see FIG. 12 and the like), but the present invention is not limited to this. For example, it is not necessary to use the bumps 521 and 522 of the COF 52 as in the seventh embodiment shown in FIG. In this case, the first external electrode 341 may be connected to the wiring 76 and the second external electrode 342 may be connected to the wiring 77. In the example shown in FIG. 15, a separation layer 32A having no conductivity is used. The first hole portions 301 and 323 and the first hole portions 302 and 324 are both embedded with an elastic member 73 having conductivity. The wiring 76 is formed on the separation layer 32. The wiring 76 is a wiring for connecting the first external electrodes 341 that are common electrodes of the channels 70. The wiring 76 is electrically connected to the first external electrode 341 via the elastic member 73 of the first hole portions 301 and 323. The wiring 77 is a wiring for connecting the second external electrode 342 that is an individual electrode. The wiring 77 is electrically connected to the second external electrode 342 through the elastic member 73 of the first hole portions 302 and 324. In the case of the seventh embodiment, since it is not necessary to form the bumps 521 and 522 on the COF 52, the cost can be reduced.

DESCRIPTION OF SYMBOLS 1 Printer 3 Inkjet head 30 Cavity unit 32, 32A Diaphragm 34 Piezoelectric actuator element 35 Nozzle 36 Insulating layer 52 COF
70 Channels 72, 76, 77 Wiring 90 First plate member 91 Second plate members 301, 302, 323, 324 First hole 303 Pressure chamber 321, 322 Recess 341 First external electrodes 341A, 341B First protrusion 342 Second external electrodes 342A, 342B Second protrusion 343 Laminated bodies 343A, 343B, 343C, 343D Piezoelectric layers 344, 345 First internal electrode 346 Second internal electrode 347 First end 348 Second end 521, 522 Bump 751, 752 Groove 901 Second hole

Claims (19)

An inkjet head having a plurality of channels each including a plurality of nozzles that eject ink and an ink chamber that stores the ink ejected from the nozzle,
An ink chamber forming member which is a member having a hole or a groove forming the ink chamber;
A layered member stacked on the ink chamber forming member and in contact with the ink chamber;
A piezoelectric actuator element disposed on the layered member,
The actuator element is:
A laminate in which a plurality of piezoelectric layers are laminated;
A first internal electrode disposed between two adjacent piezoelectric layers of the laminate and extending to a first end of the laminate;
A second electrode that is opposed to the first internal electrode with at least one piezoelectric layer interposed therebetween, is disposed between two adjacent piezoelectric layers of the multilayer body, and is located at a position different from the first end of the multilayer body. A second internal electrode extending to the end;
A first external electrode provided at the first end and connected to the first internal electrode, the first external electrode having a first protrusion protruding in the stacking direction of the stacked body;
An electrode provided at the second end and connected to the second internal electrode, the second external electrode having a second protruding portion protruding in the stacking direction of the stacked body;
At least one of the ink forming member and the layered member has a first hole portion provided at a position facing the first projecting portion and the second projecting portion. The first hole is formed in the ink chamber forming member,
The inkjet head according to claim 1, wherein the first hole formed in the ink chamber forming member is covered with the layered member. The layered member has conductivity,
The first external electrodes of the piezoelectric actuator elements of the channels are electrically connected to each other via the layered member;
The inkjet head according to claim 2, wherein the second external electrode and the layered member are insulated by an insulating layer laminated on the layered member. A wiring member provided with a bump connected to the second external electrode;
The insulating layer extends over the layered member, and a plurality of the insulating layers are stacked on the layered member,
The piezoelectric actuator element is disposed on each of the plurality of insulating layers so that the second external electrodes of the two rows of the piezoelectric actuator elements are opposed to each other. Inkjet head. The layered member does not have conductivity,
The inkjet head according to claim 2, wherein the first external electrodes of the actuator elements of the channels are electrically connected to each other through a wiring formed on the layered member. The layered member has conductivity,
The first external electrode is electrically connected to the layered member,
The inkjet head according to claim 1, wherein the second external electrode is insulated from the layered member by the first hole provided in the layered member.   The inkjet head according to claim 6, wherein the first hole portion facing the second projecting portion of the second external electrode is filled with an elastic member having an insulating property.   The layered member has at least one provided on the ink chamber side from the first hole so as to face the first hole in a direction in which the first external electrode and the second external electrode face each other. The ink jet head according to claim 1, wherein a groove is provided.   9. The inkjet head according to claim 1, wherein the first protrusion and the second protrusion protruding from the stacked body in the stacking direction are positioned by the first hole. A method of manufacturing an ink jet head having a plurality of channels each including a plurality of nozzles for discharging ink and an ink chamber for storing the ink discharged from the nozzles,
An ink chamber forming member forming step of forming an ink chamber forming member which is a member having a hole or a groove forming the ink chamber;
A first hole forming step for forming a pair of first holes in at least one of the ink chamber forming member formed by the ink chamber forming member forming step and the layered member disposed on the ink chamber forming member. When,
A layered member stacking step of stacking the layered member in contact with the ink chamber on the ink chamber forming member;
An actuator placement step of placing a piezoelectric actuator element on the layered member,
The actuator element is:
A laminate in which a plurality of piezoelectric layers are laminated;
A first internal electrode disposed between two adjacent piezoelectric layers of the laminate and extending to a first end of the laminate;
A second electrode that is opposed to the first internal electrode with at least one piezoelectric layer interposed therebetween, is disposed between two adjacent piezoelectric layers of the multilayer body, and is located at a position different from the first end of the multilayer body. A second internal electrode extending to the end;
A first external electrode provided at the first end and connected to the first internal electrode, the first external electrode having a first protrusion protruding in the stacking direction of the stacked body;
An electrode provided at the second end and connected to the second internal electrode, the second external electrode having a second protruding portion protruding in the stacking direction of the stacked body;
In the method of manufacturing an ink jet head, the actuator arranging step arranges the piezoelectric actuator element at a position where the first projecting portion and the second projecting portion are opposed to the first hole portion. The first hole forming step forms the first hole in the ink chamber forming member,
The method for manufacturing an ink jet head according to claim 10, wherein the layered member stacking step stacks the layered member so as to cover the first hole formed in the ink chamber forming member. An insulating layer forming step of forming an insulating layer on the layered member stacked by the layered member stacking step;
The layered member laminated by the layered member lamination step has conductivity,
In the actuator arranging step, the first external electrode of the piezoelectric actuator element of each channel is electrically connected to the layered member, and the second external electrode is formed on the insulating layer formed by the insulating layer forming step. The method of manufacturing an ink jet head according to claim 10, wherein the ink jet head is disposed. The insulating layer forming step forms a plurality of the insulating layers so as to extend on the layered member,
In the actuator arranging step, the actuator elements are arranged on each of the plurality of insulating layers formed by the insulating layer forming step so that the second external electrodes of the actuator elements in two rows face each other. The method of manufacturing an ink-jet head according to claim 12. A wiring forming step of forming wiring on the layered member;
The actuator placement step electrically connects the first external electrode of the actuator element of each channel to the wiring formed by the wiring formation step,
The method of manufacturing an ink jet head according to claim 10, wherein the layered member does not have conductivity. The first hole forming step forms the first hole at least in the layered member,
The actuator placement step electrically connects the first external electrode to the layered member, and places the second external electrode in the first hole formed in the layered member,
The method for manufacturing an ink jet head according to claim 9, wherein the layered member has conductivity.   The method of manufacturing an ink jet head according to claim 15, further comprising an embedding step of filling the first hole facing the second external electrode with an insulating elastic member.   In the direction in which the first external electrode and the second external electrode correspond to each other, at least one groove provided on the ink chamber side from the first hole so as to face the first hole is formed in the layered member. The method for manufacturing an ink jet head according to claim 10, further comprising a groove forming step to be formed.   When the actuator arranging step arranges the piezoelectric actuator element, the first projecting portion of the first external electrode and the second projecting portion of the second external electrode projecting in the stacking direction from the stacked body are the first projecting portion. The method of manufacturing an ink jet head according to claim 9, wherein the ink jet head is positioned by one hole portion. The actuator placement step includes
The piezoelectric member is formed in the second hole portion of the first plate member having a plurality of second hole portions provided at positions corresponding to the ink chambers of the ink chamber forming member formed by the ink chamber forming member forming step. A first arrangement step of arranging actuator elements;
An adhesion step of adhering the piezoelectric actuator element arranged in the second hole of the first plate-like member to the second plate-like member by the first arrangement step;
The second arrangement step of arranging the piezoelectric actuator element bonded to the second plate-shaped member by the bonding step on the ink chamber. Manufacturing method of the inkjet head.

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