JPWO2011062061A1 - Inkjet head manufacturing method - Google Patents

Abstract

A plurality of first electrodes for applying an electric signal to each pressure generating element are arranged in a plurality of rows on one surface of the head chip, and each of the first electrodes of the head chip is arranged. A method of manufacturing an inkjet head, wherein the second electrodes for connecting to the drive circuit are electrically connected to each other, wherein the second electrodes correspond to the first electrodes in one row. The second electrode corresponding to the row of the first electrodes via an insulating layer between the second electrode and the second electrode corresponding to the other first electrode adjacent to the row of the first electrodes. The electrodes are sequentially formed on the first electrode forming surface side of the head chip while being laminated in the thickness direction of the insulating layer for each electrode, and one end of each of the second electrode and the insulating layer is formed on the head. Form so that it protrudes to the same end side of the chip A method of manufacturing an ink jet head, characterized in that.

Description

  The present invention relates to a method for manufacturing an inkjet head, and more particularly, an inkjet head that can easily perform electrical connection between an electrode formed on one end face of a head chip in which a large number of pressure chambers are arranged and a drive circuit. It relates to the manufacturing method.

  Ink jet heads enable high-resolution and high-speed recording, so that ejected liquid droplets are miniaturized and nozzles tend to be arranged at high density. For this reason, in the ink jet head, a large number of pressure chambers and a large number of pressure generating elements that change the pressure in each pressure chamber are arranged in a plurality of rows on the head chip to increase the density of the nozzles. In such a head chip, a large number of electrodes for applying an electric signal to each pressure generating element are arranged on a single end face over a plurality of rows. Therefore, the electrical connection with the drive circuit is performed using this end face.

  Conventionally, as an ink-jet head having such a head chip, a groove serving as a channel (pressure chamber) is ground on a piezoelectric element substrate, a drive electrode is formed on a partition partitioning the channel, and a voltage is applied to the drive electrode. A shear mode type head chip that shears and deforms the partition walls and discharges ink in the channels from the nozzles, a so-called harmonica structure head in which the opening of the channel is arranged to face the front end face and the rear end face of the head chip. An inkjet head using a chip is known. In such a harmonica head chip, electrodes electrically connected to drive electrodes arranged in each pressure chamber are arranged on the rear end face of the head chip.

  As a method for electrically connecting the electrodes arranged on the rear end surface of the head chip having such a harmonica structure and the drive circuit, the electrodes are arranged at the same pitch as the pitch of the electrodes on the rear end surface of the head chip. By connecting an external wiring substrate made of a hard material such as glass or ceramics on which the formed wiring electrodes are formed so that the end of the wiring substrate protrudes to the side of the head chip, the electrode connected to each drive electrode is connected to the head chip. Each drive electrode and drive circuit are connected to the FPC and the external wiring board by pulling out to the end of the external wiring board projecting sideways and connecting an FPC (flexible printed circuit) to the end of the external wiring board. A method of electrical connection via electrodes is known (Patent Document 1).

  In this method, even if the head chip has two channel rows, both ends of the external wiring board are formed by forming the external wiring board so as to protrude from the opposite ends of the head chip. Each can be connected to the FPC using the unit.

  However, in the case of a head chip in which three or more channel rows are formed in order to increase the density of the nozzles, the FPC is connected to each drive electrode of the inner channel row sandwiched between the channel rows at both ends. Will be difficult.

  In FIG. 9 of Patent Document 1, in order to connect each drive electrode of the inner channel row sandwiched between the channel rows at both ends and the FPC, a through hole is provided in the external wiring board, and the inside is provided with a conductive material. In this method, a through electrode is formed by filling it with each other, and each drive electrode of the inner channel row is drawn out to the surface opposite to the bonding surface with the head chip in the external wiring substrate through this through electrode. In addition, it is necessary to previously form the through electrode on the external wiring board, and there is a problem that the production of the external wiring board is complicated.

  In this method, the FPC must be connected to both sides of the end portion of the external wiring board. Therefore, after connecting the FPC to one surface of the end portion of the external wiring board, the head chip to which the FPC is connected is repeated, and another FPC is connected to the other surface of the end portion of the external wiring substrate. Therefore, there is also a problem that the FPC connection work is complicated.

  As one of the methods for solving such a problem, an electrode corresponding to the inner channel row of the plurality of channel rows is arranged between each channel of the outer channel row adjacent thereto and each electrode corresponding to the channel. There is known a method of drawing out to the end of the head chip by passing between the two (Patent Document 2).

  However, this method forms all the electrodes corresponding to all the channel rows directly on the rear end face of the head chip. Therefore, as the nozzle density increases, that is, as the number of channel rows increases, Since the area where other electrodes can be formed becomes narrower and the width of the electrode itself is inevitably narrowed, there is a problem that the risk of disconnection and short-circuiting of the electrode is increased, which is applicable. There is a limit to the number of valid channel strings.

  In addition, when connecting with the FPC only on one end side of the head chip in order to bring the FPC pull-out directions from the head chip into the same direction, any of the above methods can be applied to two channel columns. This is a limit and cannot be applied to a head chip having three or more channel rows.

  Incidentally, Patent Document 3 proposes a method of forming wirings on a substrate with high density. In this method, wiring on the surface of the substrate is extended in the thickness direction of the substrate through a through hole, and a large number of such substrates are stacked to form a multilayer substrate in which the wiring on the surface of each substrate is drawn out on one surface. . Accordingly, by using such a multilayer substrate instead of the above-described external wiring substrate, each electrode arranged on the rear end surface of the head chip having three or more channel rows can be connected to the FPC. Can be considered.

  However, the method of extending the wiring in the thickness direction of the substrate through the through hole requires formation of a land having a diameter larger than the wiring width around the through hole. For this reason, there is a limit to narrowing the wiring pitch per substrate due to the large-diameter land. Further, since the wiring of this multilayer substrate is a multilayer wiring through a through hole, it is difficult and expensive to manufacture. In addition, when connecting each electrode of this multilayer substrate to each electrode formed in a plurality of rows on the end face of the head chip, positional displacement between the electrodes occurs due to the expansion and contraction of the substrate material due to heat, and all the electrodes are There is a problem that it is difficult to connect with high reliability. Since such a problem becomes more prominent as the density of the multi-row nozzle becomes higher, each multi-layer substrate is used in place of the external wiring substrate described above, and each of the head chips is formed in a plurality of rows. In practice, it is extremely difficult to make electrical connection with the electrodes.

JP 2006-82396 A JP 2002-283560 A JP 2006-103117 A

  Therefore, the present invention can easily connect an external electrode to be connected to a drive circuit to each of a plurality of rows of electrodes arranged on one end face of the head chip without causing a positional shift. Even if the number of rows of electrodes arranged on the end surface of the head chip increases, there is no risk of disconnection or short-circuiting of the external electrodes, and all of the external electrodes can be pulled out to the same end side of the head chip. An object of the present invention is to provide a method for manufacturing an ink jet head.

  The above problems are solved by the following inventions.

  The invention according to claim 1 has a head chip comprising a plurality of pressure chambers to which ink is supplied and a plurality of pressure generating elements for generating a pressure change in each of the pressure chambers. The plurality of first electrodes for applying an electric signal to each of the pressure generating elements are arranged in a plurality of rows, and each of the first electrodes of the head chip is driven. A method of manufacturing an inkjet head, wherein second electrodes for connecting to a circuit are formed so as to be electrically connected to each other, wherein the second electrodes correspond to the first electrodes in one row. For each of the second electrodes corresponding to the first electrode row, an insulating layer is interposed between the first electrode and the second electrode corresponding to the other one of the first electrodes adjacent to the first electrode row. While stacking in the thickness direction of the insulating layer, the head It is formed sequentially on the first electrode forming surface side of the chip, and one end portion of each of the second electrode and the insulating layer is formed so as to protrude to the same end portion side of the head chip. This is a method for manufacturing an inkjet head.

  According to a second aspect of the present invention, the second electrodes respectively corresponding to the adjacent rows of the first electrodes are overlapped with each other in the thickness direction of the insulating layer at a portion protruding to the same end portion side of the head chip. The inkjet head manufacturing method according to claim 1, wherein the inkjet head is formed as follows.

  According to a third aspect of the present invention, each of the rows of the first electrodes is formed on a surface of the insulating layer that is first formed with respect to the first electrode forming surface side of the head chip and in contact with the first electrode forming surface. A second electrode corresponding to the first electrode is formed in advance, and the insulating layer is bonded to the head chip, whereby each first electrode in the row of the first electrodes and the second electrode formed in advance The method for manufacturing an ink jet head according to claim 1, wherein the two are electrically connected.

  According to a fourth aspect of the present invention, the second electrode of the insulating layer is formed on the surface of the insulating layer opposite to the first electrode forming surface side of the head chip. 4. The inkjet head manufacturing method according to claim 1, wherein the inkjet head is formed so as to be electrically connected to the corresponding first electrode via an end surface adjacent to the surface from the back surface. 5. Is the method.

  According to a fifth aspect of the present invention, the second electrode formed on the surface of the insulating layer opposite to the first electrode forming surface side of the head chip passes through a through hole formed in the insulating layer. The inkjet head manufacturing method according to claim 1, wherein the inkjet head is formed so as to be electrically connected to the corresponding first electrode.

  The invention according to claim 6 has a removing step of removing an unnecessary portion of the insulating layer on which the second electrode is formed. Manufacturing an inkjet head according to any one of claims 1 to 5 Is the method.

In the invention according to claim 7, the insulating layer is made of an organic film,
The inkjet head manufacturing method according to claim 6, wherein the removing step is performed by removing unnecessary regions of the insulating layer by etching or laser.

  The invention according to claim 8 is the method of manufacturing an ink jet head according to claim 7, wherein the insulating layer has a thickness of 20 μm or less.

  According to a ninth aspect of the present invention, the pressure generating element is a piezoelectric element, and the head chip includes a plurality of pressure chambers formed in a groove shape, and a partition wall formed of the piezoelectric elements between adjacent pressure chambers. Alternatingly arranged rows are arranged over a plurality of rows, the pressure chambers open to the front end surface and the rear end surface of the head chip, nozzles are disposed on the front end surfaces, and the pressure chambers are arranged in the pressure chambers. A drive electrode is formed on the facing partition, and the partition is deformed by applying an electric signal to the drive electrode, and ink in the pressure chamber is ejected from the nozzle. The method of manufacturing an ink jet head according to claim 1, wherein the first electrodes are arranged in a plurality of rows.

  According to the present invention, it is possible to easily connect external electrodes to be connected to a drive circuit to each of a plurality of rows of electrodes arranged on one end face of the head chip without causing a positional shift. Even if the number of rows of electrodes arranged on the end surface of the head chip increases, there is no risk of disconnection or short-circuiting of the external electrodes, and all of the external electrodes can be pulled out to the same end side of the head chip. A method for manufacturing an ink jet head can be provided.

  In particular, according to the present invention, the head chip can be easily connected to each electrode formed in three or more rows on the end face of the head chip without causing any positional displacement, and all the external electrodes can be connected. The head chip can be pulled out to the same end side, and a high-resolution and high-speed inkjet head can be easily manufactured.

The figure explaining an example of the method of manufacturing a head chip The figure explaining the method of forming the 1st electrode in a head chip The figure which looked at the head chip in which the 1st electrode was formed from the rear end face side The figure explaining the method of laminating the first insulating layer on the rear end face of the head chip (A) is sectional drawing which follows the (i)-(i) line of FIG. 4, (b) is sectional drawing which follows the (ii)-(ii) line of FIG. The figure explaining the method of forming the 2nd electrode in the rear end face of a head chip (A) is sectional drawing which follows the (iii)-(iii) line of FIG. 6, (b) is sectional drawing which follows the (iv)-(iv) line of FIG. The figure which looked at the head chip in which the 2nd electrode was formed from the rear end face side. (A) is sectional drawing which follows the (v)-(v) line of FIG. 8, (b) is sectional drawing which follows the (vi)-(vi) line of FIG. View of the head chip from which the unnecessary area of the first insulating layer has been removed viewed from the rear end face side (A) is sectional drawing which follows the (vii)-(vii) line of FIG. 10, (b) is sectional drawing which follows the (viii)-(viii) line of FIG. The figure explaining the method of laminating | stacking the insulating layer of the 2nd time on the rear-end surface of a head chip. (A) is sectional drawing which follows the (ix)-(ix) line of FIG. 12, (b) is sectional drawing which follows the (x)-(x) line of FIG. A view of the head chip from which the unnecessary region of the second insulating layer has been removed viewed from the rear end surface side (A) is sectional drawing which follows the (xi)-(xi) line of FIG. 14, (b) is sectional drawing which follows the (xii)-(xii) line of FIG. Exploded perspective view of inkjet head FIG. 6 is a view for explaining a method of laminating a second insulating layer on the rear end face of a head chip having three channel rows according to the second embodiment. (A) is a sectional view taken along line (xiii)-(xiii) in FIG. 17, (b) is a sectional view taken along line (xiv)-(xiv) in FIG. 17, and (c) is (xv) in FIG. -Cross section along line (xv) The figure explaining the method of forming a 2nd electrode on the insulating layer of the 2nd time in the rear-end surface of a head chip. (A) is a sectional view taken along line (xvi)-(xvi) in FIG. 19, (b) is a sectional view taken along line (xvii)-(xvii) in FIG. 19, and (c) is (xviii) in FIG. -Cross section along line (xviii) A view of the head chip from which the unnecessary region of the second insulating layer has been removed viewed from the rear end surface side (A) is a sectional view taken along line (xix)-(xix) in FIG. 21, (b) is a sectional view taken along line (xx)-(xx) in FIG. 21, and (c) is (xxi) in FIG. -Cross section along line (xxi) The figure explaining the method of laminating | stacking the 3rd insulating layer on the rear-end surface of a head chip (A) is a sectional view taken along line (xxii)-(xxii) in FIG. 23, (b) is a sectional view taken along line (xxiii)-(xxiii) in FIG. 23, and (c) is (xxiv) in FIG. -Cross section along line (xxiv) A view of the head chip from which the unnecessary region of the third insulating layer has been removed viewed from the rear end face side (A) is a sectional view taken along line (xxii)-(xxii) in FIG. 25, (b) is a sectional view taken along line (xxiii)-(xxiii) in FIG. 25, and (c) is (xxiv) in FIG. -Cross section along line (xxiv) The figure which looked at the head chip which has three rows of channel rows concerning another channel arrangement form from the back end face side Sectional drawing which shows the aspect which formed the through-hole in the insulating layer which concerns on 4th Embodiment The figure which shows the inkjet head which concerns on 5th Embodiment.

  In the present invention, the ink jet head has a head chip including a large number of pressure chambers to which ink is supplied and a large number of pressure generating elements for generating a pressure change in each pressure chamber. A plurality of first electrodes for applying an electric signal to each pressure generating element are arranged in a plurality of rows on one end face of the head chip, and each head electrode has a first electrode. On the other hand, in order to form the second electrodes, which are external electrodes for connecting to the drive circuit, so as to be electrically connected to each other, the second electrodes are arranged on the end face of the head chip. It is formed sequentially every time and all the second electrodes are drawn out to the same end side of the head chip.

  That is, according to the present invention, the second electrode is provided between the second electrode corresponding to the first electrode in one column and the second electrode corresponding to the other first electrode adjacent to the first electrode column. The first electrode is formed in order on the first electrode formation surface of the head chip while being laminated in the thickness direction of the insulating layer for each row of the first electrode via the insulating layer, and one of each of the second electrode and the insulating layer. The end portion is formed so as to protrude to the same end portion side of the head chip. Thus, a laminated structure of the second electrode and the insulating layer is formed on the first electrode formation surface of the head chip corresponding to the number of rows of the first electrodes. The end portion of the head chip is an end portion in the arrangement direction of the first electrodes when the head chip is viewed from the first electrode formation surface side.

  According to the present invention, with respect to the end surface of the head chip in which the first electrodes are arranged and formed over a plurality of rows, it is preferably arranged for each row of the first electrodes, at either one end of the head chip. A second electrode corresponding to the first electrode column is formed by wiring for each first electrode column that is sequentially adjacent to the first electrode column. For this reason, as in the prior art, separate substrates, such as external wiring boards, in which electrodes are previously formed over a plurality of rows are electrically connected to each other while being aligned with the electrodes of the plurality of rows of the head chip. Compared to the case, the complexity of the connection work is reduced.

  In addition, since all the second electrodes are formed so as to protrude from one end side of the head chip, even when an external substrate such as an FPC is connected to the second electrode, only the one end side of the head chip is provided. However, it is only necessary to work from one direction, and the connection work is simplified.

  The means for forming the second electrode on the insulating layer is not particularly limited, but in general, a metal material to be an electrode is applied on the insulating layer by a vapor deposition method or a sputtering method to form a metal film. The second electrode can be patterned using a technique for forming a pattern by exposure and development using a mask on the metal film.

  In addition, according to the present invention, the second electrodes that are electrically connected corresponding to the first electrodes in different rows among the plurality of rows of the first electrodes arranged in the head chip are provided between the insulating layers. Therefore, even if the number of first electrodes is increased, the pitch between the second electrodes does not become narrower. Accordingly, since it is not necessary to reduce the width of the second electrode as the number of first electrodes arranged increases, there is no possibility that the second electrode is disconnected or short-circuited.

  In particular, in the present invention, the head chip is preferably formed by forming three or more rows of the first electrodes. In the present invention, even if the head chip is formed by forming three or more rows of the first electrodes, the second electrode is also applied to the inner rows of the first electrodes sandwiched between the rows of the first electrodes at both ends. The electrodes can be easily connected and formed without fear of displacement, disconnection, or short circuit.

  In the present invention, it is preferable that the second electrodes respectively corresponding to the adjacent first electrode rows are formed so as to overlap each other in the thickness direction of the insulating layer at a portion protruding to the same end side of the head chip. Since all the second electrodes protruding from the same end side of the head chip can be arranged at the same pitch, even when an external substrate such as an FPC is connected to the protruding portion, the connection work is easily performed. Will be able to.

  Further, according to the present invention, the first insulating layer formed first with respect to the first electrode forming surface of the head chip is arranged on the surface in contact with the first electrode forming surface, and is arranged at one end of the head chip. A second electrode corresponding to each first electrode in one electrode row is formed in advance, and the insulating layer is bonded to the head chip, so that each first electrode in the first electrode row is formed in advance. The second electrode can be electrically connected.

  According to this method, in addition to the effects described above, the surface of the second electrode can be exposed toward the surface opposite to the first electrode formation surface of the head chip, so that the head chip is placed on the work table. Then, when connecting an external substrate such as an FPC to the second electrode, the connection work is performed from one direction to all the second electrodes in a stable state with the first electrode forming surface side of the head chip as the lower surface. It will be more workable.

  In addition, at the time of joining the first insulating layer in which the second electrode is formed in advance, 1 corresponding to each of the first electrodes in one row arranged at one end portion of the head chip. Since it is only necessary to align the second electrodes of the rows, there is no need for the trouble of aligning the first electrodes of the rows and the second electrodes of the rows.

  By the way, when the second electrode formed on the surface opposite to the first electrode forming surface side of the head chip in the insulating layer is electrically connected to the first electrode on the end surface of the head chip, the second electrode is formed. It is necessary to wire the second electrode also in the thickness direction of the insulating layer orthogonal to the surface. For this reason, in the present invention, the second electrode formed on the surface of the insulating layer opposite to the first electrode forming surface side of the head chip is moved from the surface of the insulating layer on which the second electrode is formed to the surface. It is preferable to form it so as to be electrically connected to the corresponding first electrode via the adjacent end face.

  According to this method, the second electrode on the insulating layer is bent in the thickness direction of the insulating layer from the surface of the insulating layer (the surface on which the second electrode is formed) through its edge toward the head chip side, Since it is electrically connected to the first electrode via an end face extending in the thickness direction adjacent to the surface of the insulating layer, there is no need to form a land as in the case of using a through hole, and the insulating layer 1 The wiring pitch of the second electrode per layer does not increase. For this reason, even when the pitch between the first electrodes in one row is narrow, the corresponding second electrode can be easily formed.

  The present invention also provides a second electrode formed on the surface of the insulating layer opposite to the first electrode forming surface side of the head chip in order to wire the second electrode also in the thickness direction of the insulating layer. It can also be formed so as to be electrically connected to the corresponding first electrode via a through hole formed in the layer.

  The through hole can be formed by etching or laser processing a portion of the insulating layer bonded to the end face of the head chip that overlaps the corresponding first electrode therebelow. The through hole is filled with the metal material at the same time that the metal material at the time of forming the second electrode is filled on the insulating layer, and the second electrode on the surface of the insulating layer is filled with the second electrode. Unlike the through hole that requires a land having a diameter larger than the electrode width, wiring is performed in the thickness direction of the insulating layer and conduction with the corresponding first electrode. Two electrodes can be wired in the thickness direction of the insulating layer.

  Therefore, as in the above method, this method has an effect that the second electrode corresponding to this can be easily formed even when the pitch between the first electrodes in one row is narrow, Since the end face of the insulating layer is not used, when the insulating layer is stacked on the head chip, it is not necessary to precisely align the end of the insulating layer where the end face of the insulating layer is positioned with respect to the first electrode. There is an effect that the electrode forming operation becomes easier.

  The present invention preferably includes a removing step of removing unnecessary portions of the insulating layer on which the second electrode is formed. This removal step can be performed every time a laminated structure in which the second electrode is formed on the insulating layer on the end face of the head chip is formed. The unnecessary insulating layer is a portion of the insulating layer that does not need to fulfill the function of reinforcing the second electrode and the function of preventing the short circuit between the second electrodes laminated in the thickness direction of the insulating layer, and the second electrode is an external substrate such as an FPC. This is a portion of an insulating layer that covers an electrical connection portion with the external substrate when connecting the external substrate. The removal of the insulating layer is appropriately determined according to the material used for the insulating layer.

  In the present invention, the insulating layer is preferably made of an organic film. An insulating layer made of an organic film is easy to fabricate and easy to stack, and in the removal process, an unnecessary region of the insulating layer can be removed by etching or laser. It can be easily removed.

Examples of the organic film include various resin films such as polyimide, liquid crystal polymer, aramid, and polyethylene terephthalate. Among these, a polyimide film having good etching properties is preferable. In order to facilitate dry etching, it is desirable to use a film that is as thin as possible. In this case, an aramid film that has high strength and can maintain strength even when thin is suitable. A silicon substrate that can be dry-etched can be used for the insulating layer. However, it is necessary to use a special gas such as CF ₄ or SF ₆ for dry etching of silicon, and the apparatus is also special, so that it is generally used. Cost increases.

  The thickness of the insulating layer is preferably set to 20 μm or less in consideration of swelling in contact with ink and ease of removal work in the removal process. The lower limit is preferably 3 μm or more from the viewpoint of maintaining strength.

  In the head chip according to the present invention, the head chip has a plurality of rows in which a large number of pressure chambers formed in a groove shape and partition walls made of piezoelectric elements are alternately arranged between adjacent pressure chambers. In addition to the arrangement, the pressure chambers are opened on the front end surface and the rear end surface of the head chip, nozzles are arranged on the front end surface, a drive electrode is formed on the partition wall facing the pressure chamber, and an electric signal is applied to the drive electrode. Accordingly, it is preferable that the partition wall is deformed and the head chip has a harmonica structure in which the ink in the pressure chamber is ejected from the ejection port, and the first electrode is formed on the rear end surface of the head chip.

  In general, it is difficult for such a head chip having a harmonica structure to electrically connect each drive electrode facing the pressure chamber to the drive circuit. However, according to the present invention, each head electrode formed on the rear end surface of the head chip is provided. The second electrode, which is an external electrode for connecting to the drive circuit, can be easily connected to one electrode without causing a positional shift, and the number of pressure chambers is increased so that the first electrode Even if the number of arrangements increases, there is no fear of disconnection or short-circuiting of the second electrode, and furthermore, all of the second electrode can be easily pulled out to the same end portion side of the head chip.

  The pressure generating element in the present invention is not particularly limited as long as it generates a pressure change for ejecting ink in the pressure chamber. For example, in addition to a piezoelectric element such as PZT which is an electromechanical conversion element, a heater or the like for discharging ink by a bubble bursting action of ink may be used.

  Hereinafter, an ink jet head manufacturing method according to the present invention will be described with reference to the drawings.

<First Embodiment>
(Head chip manufacturing process)
An example of a method for manufacturing a head chip will be described with reference to FIG. Here, a head chip having a harmonica structure in which two channel rows are formed is shown.

  First, a piezoelectric element substrate 101 made of PZT or the like that has been subjected to polarization treatment (the direction of polarization is indicated by an arrow in the figure) is bonded to one substrate 100 made of ceramics using an epoxy-based adhesive. Then, a dry film 102 is attached to the surface of the piezoelectric element substrate 101 (FIG. 1A).

  Next, a plurality of parallel grooves 103 are ground from the dry film 102 side using a grinding means such as a dicing blade. Each groove 103 is ground from one end to the other end of the piezoelectric element substrate 101 and is ground at a certain depth to reach the substrate 100, so that the size and shape of the groove 103 are not substantially changed in the length direction. (FIG. 1B).

  Next, a metal material for electrode formation such as Ni, Au, Cu, and Al is applied from the ground side of the groove 103 by a sputtering method, a vapor deposition method, or the like. A metal film 104 is formed on the inner surface (FIG. 1C).

  Thereafter, the dry film 102 is removed together with the metal film 104 formed on the surface thereof, whereby the substrate 105 having the metal film 104 formed only on the inner surface of each groove 103 is obtained. Then, two similarly formed substrates 105 are prepared, aligned so that the grooves 103 of each substrate 105 coincide with each other, and bonded using an epoxy adhesive or the like, so that one row of channels is formed. One chip substrate 106 having a row is manufactured (FIG. 1D).

  Next, two chip substrates 106 obtained in this way are prepared, and the channels (grooves 103) of each chip substrate 106 are aligned so as to be shifted by a half pitch, and in a direction orthogonal to the alignment direction of the channels. After overlapping and bonding, a plurality of head chips 1 having two channel rows in which two chips are stacked are formed at a time by cutting along a direction perpendicular to the channel length direction. Each groove 103 constitutes a channel 12 that is a pressure chamber of a harmonica-structured head chip, the metal film 104 in each groove 103 serves as a drive electrode 13, and a space 11 between adjacent channels 12 serves as a partition 11 made of a piezoelectric element. The width between the cut lines C, C... Determines the drive length (L length) of the channel 12 in the head chips 1, 1... Produced thereby (FIG. 1 (e)).

  In such a head chip 1, when a predetermined voltage from the drive circuit is applied to the drive electrodes 13 of both the partition walls 11 of the channel 12, the partition wall 11 is sheared and deformed into a V shape by the piezoelectric sliding effect. A pressure change is applied to the ink, and energy for ejection is applied to the ink supplied into the channel 12. A nozzle plate, which will be described later, is bonded to one end surface of the head chip 1, and the ink in the channel 12 is ejected as fine ink droplets from the nozzle formed on the nozzle plate.

  In the head chip 1 thus obtained, channel rows in which partition walls 11 made of piezoelectric elements and channels 12 as pressure chambers are alternately arranged in parallel are arranged in two rows vertically in the figure. The number of channels in each channel row is not limited at all, but preferably the number of channels in each channel row is 2 or more.

  Since the head chip 1 is a hexahedron, the names of the end faces are defined here. In the present invention, in the head chip 1, the end surface on the ink ejection side is referred to as “front end surface”, and the opposite surface is referred to as “rear end surface”. In addition, the outer end faces located in the stacking direction of the chip substrates 106, that is, the arrangement direction of the channel rows (the vertical direction in the drawing) across the rows of the channels 12 arranged in parallel in the head chip 1, respectively, are “upper end face” and “lower It is called “end face”.

  In the following description, the column of the channel 12A positioned on the lower side in the drawing may be referred to as column A, and the column of the channel 12B positioned on the upper side may be referred to as column B as needed.

(First electrode forming step)
Next, a method for forming the first electrode on the rear end face of the head chip 1 will be described with reference to FIGS. 2 and 3 are views of the head chip 1 as seen from the rear end face side.

  First, a dry film 200 is attached to the rear end surface of the head chip 1, and openings corresponding to the entire surfaces of the channels 12A and 12B, openings 201A for forming the first electrodes 14A in the A row, and the first in the B row. An opening 201B for forming the electrode 14B is formed by exposure and development corresponding to each of the channels 12A and 12B (FIG. 2).

  Next, from the dry film 200 side, for example, Al is applied as an electrode forming metal by vacuum deposition, and an Al film is selectively formed in each of the openings 201A and 201B. With this Al film, the first electrode 14A in the A row and the first electrode 14B in the B row are formed on the rear end surface of the head chip 1 corresponding to each of the channels 12A and 12B.

  In order to ensure electrical connection between each of the first electrodes 14A and 14B and the drive electrode 13 in each of the channels 12A and 12B, it is desirable to perform the vapor deposition twice while changing the direction. Specifically, it is desirable to carry out from a direction perpendicular to the drawing surface and from 30 degrees up and down. Furthermore, as shown in FIG. 1 (d), in order to ensure electrical connection between the metal films 104 that are vertically divided, it is desirable to perform vapor deposition from the direction of 30 degrees to the right or left.

  Further, the Al film forming method is not limited to vapor deposition, and a general thin film forming technique can be employed. Further, as a method for forming the Al film, a method of applying a conductive paste by ink jet can be employed. In particular, the sputtering method is preferable because the direction of the flying metal particles is random, and the metal film can be formed even inside the channel without changing the direction. After the Al film is formed, the Al film formed on the dry film 200 is removed by dissolving and peeling the dry film 200 with a solvent. As a result, only the first electrodes 14A in the A row and the first electrodes 14B in the B row remain on the rear end surface of the head chip 1, and the rows of the first electrodes 14A and the rows of the first electrodes 14B. Are arranged in parallel to the rear end surface of the head chip 1 in the vertical direction (FIG. 3).

  In consideration of the workability of the dry film 200 in the development process and the water washing process, it is desirable that the dry film 200 is opened on the entire surface of the channels 12A and 12B. The openings on the entire surfaces of the channels 12A and 12B facilitate the removal of the developer and the washing water in the channels 12A and 12B.

(Insulating layer lamination process-first layer)
Next, an insulating layer is laminated on the rear end surface of the head chip 1. This method will be described with reference to FIGS. 4 is a view of the head chip 1 as viewed from the rear end face side, FIG. 5A is a cross-sectional view taken along line (i)-(i) in FIG. 4, and FIG. 5B is a view in FIG. (Ii) It is sectional drawing which follows a line. In FIG. 5, the drive electrodes 13 formed on the upper surfaces of the channels 12A and 12B are not shown.

  An insulating layer 21 is attached to the rear end face of the head chip 1 on which the first electrodes 14A and 14B are formed on the rear end face.

  This insulating layer 21 is made of an organic film, and the length in the horizontal direction in the drawing along the alignment direction of the channels 12A or 12B is equal to or longer than the length of the channels 12A or 12B in the head chip 1 in the alignment direction. And the length in the vertical direction in the figure along the arrangement direction of the channel rows of the B row does not overlap with the channels 12B of the B row, and the first electrodes 14B of the B row and the first electrodes 14B It is formed to have a length that greatly protrudes from the end portion 1a on the A row side of the rear end surface of the head chip 1 beyond the first electrodes 14A in the A row from the overlapping position so as to expose a part. In this state, a part of each first electrode 14B on the side of the channel 12A in the A column, each channel 12 in the A column, and each first electrode 14A are all covered with the insulating layer 21.

  Here, the insulating layer 21 has the same pitch as the first electrodes 14A on one surface in advance, corresponding to the first electrodes 14A in the A row arranged at the lowermost end of the head chip 1. In this way, the second electrode 31 is patterned (formation of the second electrode of the first layer). When one end portion 31a of each second electrode 31 is aligned with the one end portion 21a of the insulating layer 21 so as to overlap with each first electrode 14B in the B row, each first end portion in the A row The other end 31 b of each second electrode 31 is located at a position overlapping with the electrode 14 A, and extends to the front of the other end 21 b of the insulating layer 21 protruding from the head chip 1. A non-electrode forming portion 31 c that does not have the second electrode 31 is formed between the end portion 31 b and the end portion 21 b of the insulating layer 21. For this reason, when the insulating layer 21 is aligned and joined to the rear end surface of the head chip 1, the end 31b of the second electrode 31 protrudes more outward than the end 1a on the A row side of the head chip 1. In addition, the end 21 b of the insulating layer 21 is exposed so as to protrude further outward from the end 31 b of the second electrode 31.

  Thereby, each 1st electrode 14A of A row of head chip 1 is pulled out of head chip 1 by the 2nd electrode 31 which is an external electrode.

  The formation method of the second electrode 31 can be formed on one surface of the insulating layer 21 in the same manner as the pattern formation of the first electrodes 14A and 14B. Precise alignment is required for electrical connection between each first electrode 14A and each second electrode 31, but only one column of electrodes needs to be aligned, so multiple columns should be aligned at once. No complicated work is required.

The bonding of the insulating layer 21 to the rear end surface of the head chip 1 is such that the surface on which the second electrode 31 is formed faces the rear end surface of the head chip 1, and each of the first electrodes 14A in the A row and each Positioning is performed so that the second electrode 31 is electrically connected, and bonding is performed using an adhesive. Here, an epoxy adhesive (Epotech 353ND, manufactured by Epoxy Technology Co., Ltd.) was used as the adhesive, and the curing conditions were a temperature of 100 ° C., 30 minutes, and a pressure of 10 kg / cm ² .

  When the insulating layer 21 is bonded, the conduction between the first electrode 14A in the A row and the second electrode 31 is an NCP method (Non Conductive Paste :) in which electrical connection is established by pressure-bonding metal films together with an adhesive. Non-conductive paste method). In this case, the epoxy adhesive functions as an adhesive when the insulating layer 21 is bonded, and also functions as an NCP. In the case of the NCP method, connection may be difficult if the surface of the metal film is oxidized. Therefore, the surfaces of the first electrode 14A and the second electrode 31 are preferably made of a metal that is difficult to oxidize, such as Au and Pt. This can be realized by making the metal film into multiple layers.

  An ACP method (Anisotropic Conductive Paste) using an adhesive in which metal particles are dispersed in an adhesive can also be used. In this case, since the metal particles break through the oxide film on the surface of the metal film and make a connection, even if the first electrode 14A and the second electrode 31 are a metal whose surface is easily oxidized such as Al, it is easy to obtain a reliable electrical connection. .

(Second electrode formation step-second layer)
Next, on the insulating layer 21 stacked on the rear end face of the head chip 1, second electrodes corresponding to the first electrodes 14B in the B row adjacent to the rows of the first electrodes 14A in the A row are formed. This method will be described with reference to FIGS. In FIGS. 7 and 9, the drive electrodes 13 formed on the upper surfaces of the channels 12A and 12B are not shown.

  First, the dry film 4 is applied to the entire surface of the surface of the insulating layer 21 first laminated on the rear end surface of the head chip 1 and the surface exposed without being covered with the insulating layer 21 on the rear end surface of the head chip 1. Are formed on the dry film 4 by exposure and development, and openings 41 serving as second electrode formation regions corresponding to the first electrodes 14B in the B row are formed (FIGS. 6 and 7).

  Each opening 41 has an insulating layer 21 that protrudes greatly from the end 1a of the head chip 1 from between each channel 12B in the B row and one end 21a of the insulating layer 21 that overlaps each first electrode 14B in the B row. The other end 21b is formed. Here, since the channels 12A and 12B in the A row and the B row are arranged with a half-pitch shift, the openings 41 are straight from the overlapping position with the first electrodes 14B in the B row toward the A row side. It extends, passes beside each channel 12A in row A or between each channel 12A, is bent in the same lateral direction so as to overlap each first electrode 14A in row A, and then again the other end of the insulating layer 21 It is formed in a crank shape (key shape) that extends straight up to 21b.

  Next, after a metal material is applied to the surface of the dry film 4 in which the opening 41 is formed by the same method as the method of forming the first electrodes 14A and 14B, and a metal film is formed in each opening 41, respectively. Then, the dry film 4 is removed (lifted off), and the second electrode 32 is formed on the insulating layer 21 (FIGS. 8 and 9).

  Since one end on the B row side of the opening 41 of the dry film 4 is located between each channel 12 of the B row and one end portion 21a of the insulating layer 21, each opening of the B row is provided in the opening 41. A boundary portion between the first electrode 14B and one end portion 21a of the insulating layer 21 is exposed. Therefore, the end portion 32a on the B-row side of the second electrode 32 formed by applying a metal material to the opening 41 extends from the surface of the insulating layer 21 to the end surface 21c of the insulating layer 21 adjacent to the surface. By passing through, the insulating layer 21 extends in the thickness direction, is stacked on the surface of the first electrode 14B in the B row, and is electrically connected to each first electrode 14B (FIG. 9B). The second electrode 32 of the second layer and the second electrode 31 of the first layer formed in advance are viewed from the rear end surface side of the head chip 1 from the first electrode 14A in the A row. Although they overlap each other in the thickness direction of the insulating layer 21 over the portion protruding to the end 1a side, no short circuit occurs because the insulating layer 21 is interposed therebetween.

(Insulating layer removal step-first time)
Next, unnecessary regions of the insulating layer 21 are removed. This method will be described with reference to FIGS. In FIG. 11, the drive electrodes 13 formed on the upper surfaces of the channels 12A and 12B are not shown.

  In the state (FIGS. 8 and 9) in which the dry film 4 is simply removed and the second electrode 32 is formed (FIGS. 8 and 9), each channel 12A in the A row opening on the rear end surface of the head chip 1 is blocked by the insulating layer 21. Since it is impossible to supply ink to each channel 12A in the A row, the unnecessary region of the insulating layer 21 including the opening region of each channel 12A in the A row is removed thereafter.

  Here, since an organic film that can be etched is used as the insulating layer 21, unnecessary etching is performed by performing dry etching from the rear end face side of the head chip 1 to be exposed to a region other than the region where the second electrode 32 is formed. Layer 21 is removed.

  Specific dry etching means can be appropriately selected according to the resin used for the insulating layer 21. For example, when a polyimide film is used, dry etching can be performed using oxygen plasma. At this time, since the second electrode 32 is not decomposed by oxygen plasma, as shown in FIGS. 10 and 11, the second electrode 32 becomes a mask, and the insulating layer 21 underneath is left without being etched, The other insulating layer 21 is removed.

(Insulating layer lamination process-second layer)
Next, the second insulating layer 22 is laminated on the surface of the second electrode 32 from the rear end face side of the head chip 1. This method will be described with reference to FIGS. In FIG. 13, the drive electrodes 13 formed on the upper surfaces of the channels 12A and 12B are not shown.

  This insulating layer 22 is also made of the same material as that of the insulating layer 21, and all the second electrodes 32 in the portion arranged on the end 1 a side of the head chip 1 with respect to the channel 12 A of the A row on the rear end face side of the head chip 1. The end portion 22a on the side close to the channel 12A in the A row is positioned so as not to cover the channel 12A in the A row, and the end portion on the opposite side thereof. 22b extends to the same position as the end portion 21b that protrudes to the outermost side in the first insulating layer 21 that is laminated first (FIGS. 12 and 13). The insulating layer 22 functions as a reinforcing layer that reinforces the end 21b side of the second electrode 32 later.

(Insulating layer removal step-second time)
Next, unnecessary regions of the insulating layer 22 are removed. This method will be described with reference to FIGS. In FIG. 15, the drive electrodes 13 formed on the upper surfaces of the channels 12A and 12B are not shown.

  After laminating the insulating layer 22, etching is performed from the front end face side (left side in FIG. 15) of the head chip 1, and a portion exposed on the front end face side of the insulating layers 21 and 22 (broken line portion in the figure). Is removed (FIGS. 14 and 15).

  By this etching, the portions of the insulating layers 21 and 22 that protrude from the end 1a of the head chip 1 are not masked by the second electrode 31 and the second electrode 32 (including the non-electrode forming portion 31c). As a result, the end portion 32b of each second electrode 32 protrudes further outward than the second electrode 31 and the insulating layer 21, and is exposed toward the front end face side of the head chip 1 in the same manner as the second electrode 31. . Then, on the opposite surface of each second electrode 32 to the insulating layer 21, the insulating layer 22 remaining without being etched functions as a reinforcing layer, and the end portion 32 b protruding outward is further reinforced.

(External substrate, nozzle plate, ink manifold joining process)
In the head chip 1 having two channel rows of the A row and the B row manufactured as described above, the first electrode 14A of both channel rows is provided on one end side which is the lower end portion in the drawing of the rear end face. , 14B, the second electrodes 31, 32, which are external electrodes electrically connected to each other, are drawn out together. Therefore, the connection to the external substrates (FPC) 5A and 5B corresponding to the A and B rows for connection with the drive circuit can be performed only on one end side (FIG. 15, FIG. 16).

  In addition, in the present embodiment, since the second electrodes 31 and 32 are both exposed toward the front end face side of the head chip 1, the connection to the external substrates 5A and 5B is also performed on the front end face of the head chip 1. This can be done only in one direction on the side, facilitating connection work. Since the back surfaces of the second electrodes 31 and 32 are reinforced by the insulating layers 21 and 22, there is no possibility that the second electrodes 31 and 32 are damaged or deformed during the connection work.

  A nozzle plate 6 having nozzles 61 corresponding to the respective channels 12 is joined to the front end surface of the head chip 1, and a common for supplying ink into the respective channels 12A and 12B on the rear end surface side. An ink manifold 7 that forms an ink chamber is joined from above the insulating layer 22. Thereby, the inkjet head H is completed (FIG. 16).

<Second Embodiment>
Each of the above embodiments is an example of manufacturing an ink-jet head having the head chip 1 in which the channel rows are two rows of the A row and the B row. However, the present invention has three channel rows (first electrode rows). Even in the ink jet head having the above-described head chip, the insulating layer stacking step, the second electrode forming step, and the insulating layer removing step are sequentially repeated for each channel row (each first electrode row). It is possible to pull out all the second electrodes to one end side of the chip.

  FIGS. 17 to 26 show an example in which the second electrode is formed on the rear surface side of the head chip 10 having three (A to C) channel rows, as in the first embodiment. Each channel row is arranged with a shift of 1/3 pitch. In FIG. 18, FIG. 20, FIG. 22, FIG. 24, and FIG. 26, the drive electrode 13 formed on the upper surface of the channels 12A, 12B, and 12C is not shown.

  The method of forming the first electrode corresponding to the head chip 10 and each channel row is based on the two chip substrates 106 and 106 for forming the head chip 1 having two channel rows in the first embodiment. Furthermore, another chip substrate 106 is stacked, a channel row (C row) is added for one row, and a corresponding first electrode 14C is added, and each first electrode 14A in the A row and the B row is added. After the second electrodes 31 and 32 corresponding to 14B are formed, the process up to the step of removing unnecessary regions of the insulating layer 21 (insulating layer removing step-first time) is the same as in the first embodiment. Here, a description will be given starting from a method of forming the second electrode 33 on the first electrode 14C in the C row corresponding to each channel 12C in the C row thereafter. Parts having the same reference numerals as those in the first embodiment indicate parts having the same configuration.

(Insulating layer lamination process-second layer)
The second electrodes 31 and 32 are formed for the first electrodes 14A and 14B in the A row and the B row, respectively, and unnecessary regions of the insulating layer 21 are removed, and then the second layer is formed on the rear end surface of the head chip 10. The insulating layer is laminated. This method will be described with reference to FIGS.

  An insulating layer 22 made of an organic film is laminated on the rear end surface of the head chip 10 on which the second electrodes 32 corresponding to the first electrodes 14B in the B row are formed.

  The insulating layer 22 has a length in the left-right direction in the drawing along the alignment direction of the channels 12A to 12C, which is equal to or longer than the length in the alignment direction of the channels 12A, 12B, or 12C of the head chip 10. The length in the vertical direction in the drawing along the arrangement direction of each channel row in the row does not overlap with each channel 12C in the C row, and each first electrode 14C in the C row and a part of the first electrode 14C From the end portions 32b of the second electrodes 32 that are electrically connected to the first electrodes 14B in the B row, beyond the end portion 10a on the A row side in the rear end surface of the head chip 10 from the overlapping position so as to expose the It is also formed in a length that protrudes outward. Therefore, a non-electrode forming portion 32 c that does not have the second electrode 32 of the second layer is formed between the end portion 32 b of each second electrode 32 and the end portion 22 b that protrudes greatly from the insulating layer 22.

  In this state, a part of each of the first electrodes 14B, 14A, and B columns of the B-column and A-column channels 12B, 12A, B-columns and A-columns from a part of the first electrode 14C of the C-column on the B-column side. The entire region extending to the second electrode 32 is covered with the insulating layer 22.

(Second electrode formation step-third layer)
Next, a second electrode of the third layer is formed on the insulating layer 22 laminated on the rear end surface of the head chip 10. This method will be described with reference to FIGS.

  The third layer second electrode can be formed in the same manner as in the first embodiment. That is, a dry film (not shown) is formed on the entire surface of the surface of the insulating layer 22 laminated on the rear end surface of the head chip 10 and the surface exposed without being covered with the insulating layer 22 on the rear end surface of the head chip 10. In the same manner as when the second electrode 32 corresponding to the first electrode 14B in the B row is formed, a metal material is applied, and each first electrode in the C row is formed on the insulating layer 22 respectively. A second electrode 33 electrically connected to 14C is formed (FIGS. 19 and 20).

  Similarly to the second electrode 32 of the second layer, the end 33a of the second electrode 33 on the channel row side of the C row extends from the surface of the insulating layer 22 to the end surface 22c on the channel 12C side of the C row of the insulating layer 22. Are stacked on the surface of the first electrode 14C in the C row and electrically connected to each first electrode 14C (FIG. 20C).

  The second electrodes 33 pass from the first electrodes 14C in the C row to the sides and between the channels 12B in the B row, and then bend in the same lateral direction between the B row and the A row channel rows. , A crank having two bent portions so as to be overlapped with the second electrode 32 formed in the second layer after being bent in the same horizontal direction again after passing through and between each channel 12A in the A row. It is formed in a shape (key shape).

  Also in this embodiment, when viewed from the rear end face side of the head chip 10, all of the second electrodes 31 to 33 overlap each other in the thickness direction of the insulating layers 21 and 22, but the insulating layers 21 and 22 are between them. Because of the intervening, no short circuit occurs.

  Furthermore, between each channel 12A of A column, it is wired so that two 2nd electrodes 32 and 33 may pass through, but these 2nd electrodes 32 and 33 pass through this insulating layer 21, 22 via the insulating layers 21 and 22. 22 are stacked in the thickness direction, the width necessary for wiring between the channels 12A is only the width of the second electrode for one line, and even if the number of wirings of the second electrode increases, the second electrode There is no need to reduce the width of the.

(Insulating layer removal step-second time)
Next, an unnecessary region of the insulating layer 22 is removed.

  Since this insulating layer 22 is also an organic film that can be etched, dry etching is performed from the rear end surface side of the head chip 10 and exposed to a region other than the region where the second electrode 33 is formed using the second electrode 33 as a mask. The unnecessary insulating layer 22 is removed. As a result, as shown in FIGS. 21 and 22, the insulating layer 22 below the second electrode 33 remains without being etched, and the other insulating layers 22 are removed.

(Insulating layer lamination process-third layer)
Next, the third insulating layer 23 is laminated on the surface of the second electrode 33 on the rear end surface of the head chip 10. This method will be described with reference to FIGS.

  The meaning of providing the third insulating layer 23 is to make it function as a reinforcing layer in the same way as the second insulating layer 22 is provided in the first embodiment.

  In this aspect, on the rear end face side of the head chip 10, the size that can cover the entire second electrode 33 of the portion arranged on the end 10 a side of the head chip 10 with respect to the channel 12 </ b> A of the A row. And the end 23a on the side close to the channel 12A of the A row is positioned so as not to cover the channel 12A of the A row, and the end 23b on the opposite side is the outermost portion of the second electrode 33. It extends to the same position as the protruding end 33b.

(Insulating layer removal step-third time)
Thereafter, etching is performed from the front end surface side of the head chip 10 to remove the insulating layers 21, 22, and 23 exposed to the front end surface side (broken line portions in the figure) (FIGS. 25 and 25). 26).

  By this etching, the portions of the insulating layers 21, 22, and 23 that protrude from the end 10a of the head chip 10 are not masked by the second electrodes 31, 32, and 33 including the non-electrode forming portions 31c and 32c. All the second electrodes 31 to 33 are exposed toward the front end face side of the head chip 10. And the insulating layer 23 which remains without being etched on the surface opposite to the insulating layer 22 of each second electrode 33 becomes a reinforcing layer, and the protruding end 33b side is reinforced.

  The etching from the front end face side can be performed only once through the manufacturing process of the inkjet head after forming all the second electrodes and insulating layers since the second electrode of each layer can be used as a mask. .

  The head chip 10 having the three channel rows manufactured as described above is also connected to the external substrates (FPC) 5A to 5C for connection to the drive circuit in the same manner as in the first embodiment. Can be easily performed from the front end face side of the head chip 10 only on one end side on the lower end side (FIG. 26).

  Also in this case, each of the second electrodes 31 to 33 is in a state where the back side is reinforced by the insulating layers 21, 22, and 23, so that each of the second electrodes 31 to 33 is damaged or deformed during connection work. It is not.

  In the above description, each channel row of the head chip 10 is arranged with a shift of 1/3 pitch, but as shown in FIG. 27, adjacent channel rows are arranged with a half pitch shift, Even if every other channel row (channel row A row and channel row C row) is formed so as to be at the same position in the arrangement direction of the channel rows (vertical direction in the figure). Good. In such a head chip 10, when nozzle clogging occurs in one of the nozzles, a channel in another channel row at the same pitch as this channel is used instead of the channel corresponding to the nozzle. Can be dealt with.

<Third Embodiment>
In each of the embodiments described above, the method of forming the second electrodes 32 and 33 is electrically connected to the corresponding first electrodes 14B and 14C via the end faces 21c and 22c of the insulating layers 21 and 22. The second electrodes 32 and 33 are formed. Next, a through hole is formed in the insulating layer, and the corresponding first electrode and second electrode are electrically connected via the through hole. A method will be described.

  FIG. 28 is a cross-sectional view showing an electrical connection portion between the first electrode 14B and the second electrode 32 in the B row of the head chip 1 shown in the first embodiment. In FIG. 28, the drive electrode 13 formed on the upper surface of the channel 12B is not shown.

  In this case, the through hole 21B is formed by penetrating through the insulating layer 21 with the first electrode 14B using etching or laser. The through hole 21B may be formed in a corresponding position before the insulating layer 21 is bonded to the head chip 1, but is formed after the insulating layer 21 is bonded to the rear end surface of the head chip 1. Is preferred. This is because there is no need to consider a positional shift due to elongation during bonding of the insulating layer 21, and the through hole 21B can be formed without a positional shift while confirming the corresponding relationship with the corresponding first electrode 14B.

  After the through hole 21B is formed, as described above, the second electrode 32 may be formed by vapor deposition or sputtering using a dry film. The metal material applied on the insulating layer 21 by vapor deposition or sputtering becomes a wiring that fills the through hole 21B and extends in the thickness direction of the insulating layer 21, and the second electrode 32 formed on the surface of the insulating layer 21 and the second electrode 32 are formed. A through electrode portion 32B of the second electrode 32 that conducts the first electrode 14B is formed.

  The through-hole 21B and the through-electrode portion 32B do not need to form a land having a diameter larger than the hole diameter around the hole as in the case of the through-hole. For this reason, even when the channels 12 are arranged in parallel at high density, the second electrodes can be wired at high density without fear of a short circuit.

  The method of electrically connecting the first electrode and the second electrode by the through-hole and the through-electrode portion inside the through-hole is the same as the method of passing through the end face of the insulating layer, and the first electrode at any position in the head chip And the second electrode corresponding thereto can also be used.

<Fourth Embodiment>
FIG. 29A shows the driving of the long laminated body 8 that is elongated by further extending the laminated structure composed of the insulating layer and the second electrode that protrudes to one end side of the head chips 1 and 10. An ink jet head H electrically connected to the circuit 9 is shown. Since the long laminated body 8 can fulfill the function of enabling flexible wiring similarly to the FPC by using a flexible organic film as an insulating layer, a connector 81 is provided at the tip of the long laminated body 8. Thus, the connector 81 can be connected to the drive circuit 9.

  Moreover, the inkjet head H in which the long laminated body 8 is formed can be configured such that the driving IC 91 is directly mounted on the long laminated body 8 as shown in FIG.

<Others>
In the present invention, each channel of the plurality of channel rows arranged on the head chip may be formed such that the pitch of each channel matches between the channel rows.

  Further, the head chip in the present invention is not limited to a shear mode type ink jet head that discharges ink in a channel by shearing a partition wall.

  Furthermore, the present invention is not limited to forming all the second electrodes so as to be exposed toward the front end face side of the head chip, but reverses the stacking order of the second electrode and the insulating layer from the end face of the head chip. By doing so, it is needless to say that all the second electrodes can be formed so as to be exposed toward the rear end face side of the head chip.

DESCRIPTION OF SYMBOLS 1, 10 Head chip 11 Partition 12A-12C Channel 13 Drive electrode 14A-14C 1st electrode 21-23 Insulating layer 31-33 2nd electrode 4 Dry film 5 External substrate (FPC)
6 Nozzle Plate 61 Nozzle Hole 7 Ink Manifold 8 Long Laminate 81 Connector 9 Drive Circuit 91 Drive IC

Claims (9)

A head chip comprising a plurality of pressure chambers to which ink is supplied and a plurality of pressure generating elements for generating a pressure change in each of the pressure chambers; A plurality of first electrodes for applying an electrical signal to a plurality of rows are arranged in a plurality of rows, and a second for connecting to a drive circuit for each of the first electrodes of the head chip. A method of manufacturing an ink-jet head for forming electrodes so as to be electrically connected to each other,
The second electrode is disposed between the second electrode corresponding to the first electrode in one row and the second electrode corresponding to the other first electrode adjacent to the first electrode row. The first electrodes are sequentially formed on the first electrode forming surface side of the head chip while being laminated in the thickness direction of the insulating layer for each of the second electrodes corresponding to the row of the first electrodes through an insulating layer, and A method of manufacturing an ink jet head, wherein one end of each of the second electrode and the insulating layer is formed so as to protrude from the same end of the head chip.   The second electrodes corresponding to the adjacent rows of the first electrodes are formed so as to overlap each other in the thickness direction of the insulating layer at a portion protruding to the same end side of the head chip. The method of manufacturing an ink jet head according to claim 1.   A second surface corresponding to each first electrode in the row of the first electrodes is formed on a surface of the insulating layer that is first formed with respect to the first electrode forming surface side of the head chip and in contact with the first electrode forming surface. An electrode is formed in advance, and the first electrode in the first electrode row is electrically connected to the pre-formed second electrode by bonding the insulating layer to the head chip. The method of manufacturing an ink jet head according to claim 1 or 2,   The second electrode formed on the surface of the insulating layer opposite to the first electrode forming surface side of the head chip is adjacent to the surface from the surface of the insulating layer on which the second electrode is formed. The method of manufacturing an ink jet head according to claim 1, wherein the ink jet head is formed so as to be electrically connected to the corresponding first electrode via an end face.   The second electrode formed on the surface of the insulating layer opposite to the first electrode forming surface side of the head chip corresponds to the corresponding first electrode via a through hole formed in the insulating layer. The ink jet head manufacturing method according to claim 1, wherein the ink jet head is formed so as to be electrically connected to the ink jet head.   The method for manufacturing an ink jet head according to claim 1, further comprising a removing step of removing an unnecessary portion of the insulating layer on which the second electrode is formed. The insulating layer is made of an organic film,
7. The method of manufacturing an ink jet head according to claim 6, wherein the removing step is performed by removing unnecessary regions of the insulating layer by etching or laser.   The method of manufacturing an ink jet head according to claim 7, wherein the insulating layer has a thickness of 20 μm or less. The pressure generating element is a piezoelectric element;
The head chip has a plurality of pressure chambers formed in a groove shape and a plurality of rows in which partition walls made of the piezoelectric elements are alternately arranged between adjacent pressure chambers. The pressure chambers are opened on the front end surface and the rear end surface of the head chip, nozzles are disposed on the front end surface, a drive electrode is formed on the partition wall facing the pressure chamber, and an electric signal is applied to the drive electrode. By doing so, the partition wall is deformed, and the ink in the pressure chamber is ejected from the nozzle, and the first electrodes are arranged in a plurality of rows on the rear end surface of the head chip. The method for manufacturing an ink-jet head according to claim 1, wherein the ink-jet head is manufactured according to claim 1.