JP2010260187A - Wiring unit, manufacturing method for wiring unit, liquid ejection head, and manufacturing method for liquid ejection head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joining structure of a wiring unit in which a molten conductive material is less extruded and a distance is provided between a piezoelectric actuator and a wiring member when the wiring member is bonded with the piezoelectric actuator. <P>SOLUTION: A land 52 is formed on one surface of a base material 51 of a COF 50. A plate-like member equipped with a projection 101, which has a first protrusion 101a and a second protrusion 101b with smaller protrusion amount than the first protrusion, is adhesively bonded to the base material 51 at a position corresponding to the land 52 while being pressed from the other surface side to the one surface side of the base material. As the result, a first convex electrode part 52a and a second convex electrode part 52b with smaller protrusion amount than the first convex electrode part are formed on the land part 52 corresponding to the projection. The conductive material 46 is applied onto the second convex electrode part 52b. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wiring unit bonded to a substrate such as a piezoelectric actuator included in a droplet discharge head, a method for manufacturing the wiring unit, a droplet discharge head, and a method for manufacturing a droplet head.

  As an example of a droplet discharge device, an ink jet printer includes an ink jet head that discharges ink. The inkjet head includes a plurality of nozzles that eject ink, a flow path unit having a plurality of pressure chambers corresponding to the nozzles, and a stacked piezoelectric actuator in which piezoelectric layers are stacked. A plurality of surface electrodes corresponding to the pressure chambers are formed on the surface of the piezoelectric actuator. A printed circuit board (FPC) having a plurality of wirings and terminal portions for supplying a driving voltage for driving the piezoelectric actuator to the surface electrode is overlapped on the piezoelectric actuator and joined to each surface electrode and the terminal portion. And are electrically connected. In the inkjet head, a driving voltage is selectively supplied to the surface electrode via the FPC, the piezoelectric layer corresponding to the surface electrode is deformed, and discharge pressure is applied to the ink in the corresponding pressure chamber, so that the ink from the nozzle Can be discharged.

  Conventionally, according to Patent Document 1, the solder melted by heating to the solder melting point and crimping both to the solder melting point via the bump electrode of the conductive brazing material such as solder between the terminal portion and the surface electrode, Electrically and mechanically connected by alloying with the terminal portion and the electrode interposed. At this time, the molten solder flows out to the periphery of the surface electrode due to the variation in the amount of solder, causing an electrical short circuit with the adjacent adjacent electrode, or the solder is cured on the surface of the region corresponding to the active portion of the piezoelectric layer. This may affect the ink ejection operation. Further, since the distance between the piezoelectric layer and the FPC cannot be obtained by protruding, the surface of the piezoelectric layer and the FPC are likely to come into contact with each other. Such protrusion is caused not only by the conductive brazing material but also by using a meltable conductive material.

  Further, according to Patent Document 2, an FPC bonding structure that does not require a conductive material to be melted is disclosed. In the area where the terminal part of the base film of the FPC is formed, the wiring and the terminal part are covered, and a synthetic resin paste having thermosetting and insulating properties is applied and heated to be in a semi-cured state. The synthetic resin layer is formed. The piezoelectric actuator is provided with a conductive resin bump electrode on the surface electrode, the FPC is thermocompression bonded to the piezoelectric unit, and the terminal portion of the FPC is pressed against the bump electrode of the piezoelectric actuator. As a result, the bump passes through the uncured synthetic resin layer and comes into contact with the corresponding terminal portion, and the uncured synthetic resin material flows along the surface so as to surround the surface of the bump. Cures in contact with In this way, the synthetic resin surrounds the bumps and hardens in an integrated state in contact with the surface electrode, and the terminal portion is in direct contact with and electrically connected to the corresponding bump. In the joint structure as in Patent Document 2, the melted conductive brazing material does not protrude from between the surface electrode and the terminal electrode as in Patent Document 1, and the distance between the piezoelectric layer and the FPC is gained by the bump. It is possible to prevent electrical short-circuits and obstruction of the active part.

JP 2005-313335 A JP 2005-305847 A

  However, since the joint portion of the FPC as in Patent Document 2 is in a state in which the surface electrode and the terminal electrode are mechanically joined by the synthetic resin, it is alloyed with each electrode by a conductive brazing material such as solder. Compared with the joint, the joint strength is weak and the FPC is easily peeled off from the piezoelectric actuator. And since the conduction | electrical_connection state of a surface electrode and a terminal part is ensured in the state which the bump and the terminal part are contacting directly, if such peeling arises, it will become easy to generate | occur | produce an electrical malfunction. Moreover, the bump electrode of patent document 2 is a resin-made bump electrode which has electroconductivity, and when the FPC is thermocompression bonded to the piezoelectric actuator, the bump electrode provided on the piezoelectric layer is an uncured synthetic resin layer. Since the leading end is in direct contact with the terminal electrode to conduct through, the applied pressure generated in the piezoelectric layer is larger than that in the case where the molten solder as in Patent Document 1 is pressed and bonded to the surface electrode. (In Patent Document 1, a large pressing force cannot be applied because the solder must be pressed to such an extent that it does not protrude beyond the surface electrode.) Therefore, a minute amount around the position where the bump electrode of the piezoelectric layer is provided. Cracks and chips are easily generated, and it becomes fragile as compared with a portion where no bump electrode is provided. In particular, in the case of a piezoelectric actuator formed by laminating a small number of piezoelectric layers, the strength of the piezoelectric layer is weak so that the piezoelectric layer may be damaged, and the ink ejection characteristics are likely to be greatly affected. Further, the internal electrode in the piezoelectric actuator may be damaged and cause an electrical disconnection.

  Therefore, when it is considered that the FPC and the piezoelectric actuator have a bonding strength to prevent the peeling between the two while preventing cracks in the piezoelectric layer, a bonding structure using a conductive brazing material such as solder is used. Although it is preferable, there is a problem in that the electrical short circuit due to the protrusion of the molten solder and the piezoelectric layer are obstructed.

  Accordingly, the present invention has been made to solve such a problem, and suppresses the protrusion of the conductive brazing material when the wiring member and the base material such as the piezoelectric actuator are joined by the conductive brazing material such as solder. Then, it aims at providing the wiring unit which can earn the distance of a base material and a wiring board, the manufacturing method of a wiring unit, the droplet discharge head, and the manufacturing method of a droplet discharge head.

The wiring unit according to the present invention is
A plate-like member having a protruding portion on one surface; and an insulating flexible layer bonded to the one surface of the plate-like member, wherein the insulating flexible layer is a surface opposite to the plate-like member. In the insulating flexible layer, the region where the conductive layer is formed is pressed by the protruding portion of the plate-like member to form the plate-like member. By projecting to the opposite side of the member, a convex electrode having at least a tip covered with the conductive layer is formed.

  Since such a wiring unit is provided with a projecting portion serving as a core inside the convex electrode, the convex electrode is not crushed too much by pressing when the wiring unit is joined to the connection object. It can be joined in a state having a certain distance between the base material to be joined, and it is possible to prevent the connection object from being damaged.

  In addition, the protrusion has a first protrusion and a second discharge part whose protrusion is smaller than that of the first protrusion, and the convex electrode corresponds to the first protrusion. It is preferable to have a convex electrode part and a second convex electrode part corresponding to the second protruding part.

  According to this, by having the 2nd convex electrode part, when it joins with the base material side, when the 1st protrusion part with high protrusion amount contacts the base material side, it is 2nd. The convex electrode part of can have a space between the base material. Since the conductive material can be held and accommodated in this space, the conductive material can be bonded while being prevented from protruding.

  As described above, the present invention secures the distance between the base material and the wiring board by suppressing the collapse of the convex electrode even when the connection object such as the wiring member and the piezoelectric actuator is joined so as to be conductive. Can do.

1 is a schematic configuration diagram of a printer according to an embodiment of the present invention. It is a disassembled perspective view of the inkjet head of FIG. FIG. 3 is a plan view of FIG. 2. (A) is the elements on larger scale of FIG. 3, (b)-(d) is a figure of the surface of the diaphragm of (a) and each piezoelectric layer. It is the VV sectional view taken on the line of FIG. It is the VI-VI sectional view taken on the line of FIG. It is process drawing which shows the manufacturing process of an inkjet head. It is the elements on larger scale of FIG.7 (d).

  Hereinafter, preferred embodiments of the present invention will be described.

  FIG. 1 is a schematic configuration diagram of a printer 1 as a droplet discharge device having a piezoelectric actuator according to the present embodiment. The printer 1 may be applied to a single printer device, or may be applied to a multi-function printer device having a plurality of functions such as a facsimile function and a copy function. As shown in FIG. 1, the printer 1 includes a carriage 2, an inkjet head 3, a paper transport roller 4 and the like in the apparatus main body. In the following description, the direction in which the liquid is ejected from the nozzle is the downward direction, and the opposite direction is the upward direction. Moreover, when determining the direction in a figure as needed, description is provided suitably.

  The carriage 2 is a substantially box-shaped resin case whose upper surface is opened. The carriage 2 is movably mounted on a guide shaft 5 extending in the left-right direction (scanning direction) in FIG. It is configured to reciprocate in the left-right direction). In the apparatus main body, replaceable ink cartridges (not shown) for supplying a plurality of types of ink (for example, four types of black, yellow, cyan, and magenta) are left standing. It is connected to an ink jet head 3 mounted in the carriage 2 via an ink tube (not shown). Further, a sheet conveying roller 4 and a platen 6 are arranged facing the lower side of the carriage 2, and the recording sheet P is conveyed in the forward direction (paper feeding direction) in FIG. The ink jet head 3 is disposed on the lower surface of the carriage 2, and a plurality of nozzles are mounted on the surface of the carriage 2 so as to be exposed. In the printer 1, printing is performed on the recording paper P by ejecting ink from the inkjet head 3 that reciprocates in the scanning direction together with the carriage 2 onto the recording paper P that is transported in the paper feeding direction by the paper transporting roller 4. Do.

  Next, the inkjet head 3 will be described with reference to FIGS. For easy understanding of the drawing, FIG. 2 shows a land 52 and a wiring 53 (described later) in a transparent state. 3 and 4, illustration of a part of an ink flow path of the flow path unit 31 described later is omitted, and in FIG. 3, the peeling prevention plate 100 is indicated by a dotted line, and the lower electrode 43 and the intermediate electrode 44 of the piezoelectric actuator 32 are illustrated. Is omitted. In FIG. 4A, the lower electrode 43 and the intermediate electrode 44, both of which are to be illustrated by dotted lines, are illustrated by two-dot chain lines and one-dot chain lines, respectively. 4B to 4D show the positional relationship between the pressure chamber 10 and a lower electrode 43, an intermediate electrode 44, and an upper electrode 45, which will be described later, in a plan view, and the electrodes 43, 44, 45 is hatched.

  As shown in FIG. 2 to FIG. 6, the inkjet head 3 is disposed on the upper surface of the flow path unit 31 and the flow path unit 31 in which a plurality of ink flow paths such as a plurality of nozzles 15 and a plurality of pressure chambers 10 are formed. A piezoelectric actuator 32 for applying pressure for ejection from the nozzle 16 to the ink filled in the pressure chamber 10, and a drive circuit electrically and mechanically connected to the piezoelectric actuator 32 to drive the piezoelectric actuator 32. It comprises a COF 50 (Chip On Film) (wiring member) on which the provided driver IC 54 is mounted. The flow path unit 31 includes a manifold flow path 11 through which ink is supplied from the ink supply port 9 by laminating a plurality of plates 21 to 24 each having a plurality of through holes serving as ink flow paths, and An ink flow path having a plurality of individual ink flow paths from the outlet of the manifold flow path 11 to the pressure chamber 10 via the flow path 12 and further to the nozzle 15 via the flow paths 13 and 14 is formed. Yes. When the pressure is applied to the ink in the pressure chamber 10 by the piezoelectric actuator 32, the ink is ejected from the nozzle 15 communicating with the pressure chamber 10. The three plates 21 to 23 excluding the nozzle plate 24 are made of a metal material such as a stainless steel plate or a nickel alloy steel plate, and the nozzle plate 24 is made of a synthetic resin material such as polyimide.

  A plurality of pressure chambers 10 are formed through the plate thickness corresponding to the plurality of nozzles 15 in the uppermost plate 21 of the flow path unit 31, and the pressure chambers 10 are arranged in the scanning direction (left-right direction in FIG. 3). Is formed in such a manner that one end thereof communicates with the flow path 12 and the other end communicates with the nozzle 15. One pressure chamber row 8 is arranged along the paper feeding direction (vertical direction in FIG. 3), and one such pressure chamber row 8 is arranged in two rows in the scanning direction. A pressure chamber group 7 is configured. Further, five such pressure chamber groups 7 are arranged along the scanning direction. Here, the pressure chambers 10 constituting the two pressure chamber rows 8 included in one pressure chamber group 7 are arranged so as to be shifted from each other in the paper feeding direction. In addition, a plurality of nozzles 15 communicating with one end in the longitudinal direction of the plurality of pressure chambers 10 are formed in the lowermost nozzle plate 24 of the flow path unit 31 so as to open downward and penetrate therethrough. Similarly to the pressure chambers 10, the nozzles are arranged in the feed direction, form a nozzle row group, and form five nozzle row groups in the scanning direction.

Of the five pressure chamber groups 7, ink (black ink or the like) that is frequently used is ejected from the nozzles 15 corresponding to the pressure chambers 10 constituting the two on the right side of FIG. Ink is ejected from the nozzles 15 corresponding to the pressure chambers 10 of the three pressure chamber groups 7 in order from the nozzles arranged on the right side of FIG. Further, the plate 22 is formed with through holes to be the flow paths 12 and 13 at positions overlapping with both ends in the longitudinal direction of the pressure chamber 10 in plan view, and the plate 23 is a through hole to be the manifold flow path 11. Extends in the paper feeding direction corresponding to the rows of the pressure chambers 10 and overlaps with the longitudinal direction of the pressure chambers 10 in plan view and extends to a position communicating with the ink supply port 9. Next, the piezoelectric actuator 32 is A diaphragm 40, piezoelectric layers 41 and 42, a lower electrode 43, an intermediate electrode 44, and an upper electrode 45 are provided. The diaphragm 40 is made of a piezoelectric material mainly composed of lead zirconate titanate, which is a mixed crystal of lead titanate and lead zirconate, and is formed on the upper surface of the flow path unit 31 so as to cover the plurality of pressure chambers 10. Has been placed. The thickness of the diaphragm 40 is about 20 μm. The diaphragm 40 does not necessarily need to be made of a piezoelectric material. The piezoelectric layers 41 and 42 are made of the same piezoelectric material as that of the vibration plate 40, and are stacked on the upper surface of the vibration plate 40. The thicknesses of the piezoelectric layers 41 and 42 are each about 20 μm.

  The lower electrode 43 is arranged between the diaphragm 40 and the piezoelectric layer 41, and corresponds to each pressure chamber group 7 as shown in FIG. It extends in the paper feed direction along the pressure chamber row 8 and faces the plurality of pressure chambers 10 constituting the two pressure chamber rows 8 so as to overlap in plan view. Although not shown, the portions extending in the paper feeding direction corresponding to each pressure chamber group 7 are connected to each other, and a connection terminal (not shown) is provided. The connection terminal is connected to a land of a wiring (not shown) on the COF 50, and the lower electrode 43 is always held at the ground potential via the wiring.

  The intermediate electrode 44 is disposed between the piezoelectric layer 41 and the piezoelectric layer 42, and each of the pressure chamber groups 7 has a plurality of facing portions 44a and connection portions 44b and 44c as shown in FIG. 4C. have. The plurality of facing portions 44a have a substantially rectangular planar shape whose length in the paper feeding direction is shorter than that of the pressure chamber 10, and is disposed so as to face a substantially central portion in the paper feeding direction of the plurality of pressure chambers 10. Has been.

  The connecting portion 44b extends in the paper feeding direction, and among the two pressure chamber rows 8 constituting each pressure chamber group 7, a plurality of pressure chambers 10 constituting the pressure chamber row 8 arranged on the right side in FIG. 4 are connected to each other on the right side in FIG. 4. The connecting portion 44c extends in the paper feeding direction, and among the two pressure chamber rows 8 constituting each pressure chamber group 7, a plurality of pressure chambers 10 constituting the pressure chamber row 8 arranged on the left side in FIG. 4 are connected to each other on the left side in FIG. The intermediate electrode 44 is connected to a connection terminal (not shown) and a land of the intermediate electrode wiring on the COF 50, and is always held at a predetermined positive potential (for example, about 20 V) via the wiring. .

The plurality of upper electrodes 45 (surface electrodes) correspond to the plurality of pressure chambers 10 on the upper surface of the piezoelectric layer 42 (the surface of the piezoelectric actuator) as shown in FIGS. 3 and 4D. Are arranged in the paper feed direction, and form an upper electrode row group, and two rows of upper electrodes 45 included in one upper electrode row group in the scanning direction are arranged. The constituting upper electrodes 45 are arranged so as to be shifted from each other in the paper feeding direction.
Further, the upper electrode 45 has a substantially rectangular planar shape whose length in the paper feed direction is longer than the facing portion 44 a of the intermediate electrode 44, and the upper electrode 45 is a main electrode facing substantially the entire area of the pressure chamber 10. A portion of the portion 45b and the main electrode portion 45b at the end opposite to the nozzle 15 in the scanning direction extend to a portion that does not face the pressure chamber 10 in the scanning direction, and this portion is a land 52 of the wiring 53 described later of the COF 50. It becomes the connection terminal part 45a connected to. The electrodes 43, 44, 45 and the connection terminal portion 45a are formed by printing with a thin Ag-Pd material (about 1 to 2 μm), and the surface of the connection terminal portion 45a includes glass frit. An external electrode 47 made of an Ag paste material is disposed.

  On the surface of the external electrode 47, a conductive brazing material 46 such as solder provided on the land 52 of the COF 50 (in this embodiment, solder is used, hereinafter referred to as solder 46) is joined. The external electrode 47 is provided in order to improve the bonding strength with the conductive brazing material 46, and is printed and formed so as to be thick (about 10 to 20 μm). Since the upper electrode 45 and the connection terminal portion 45 a provided with the solder 46 are made of an Ag—Pd-based material that is compatible with the solder 46, so-called “silver erosion” in which silver is diffused into the molten solder 46. May occur and electrical disconnection may occur. Therefore, it is preferable that the external electrode 47 is disposed on the connection terminal portion 45a, and electrical disconnection is prevented by making contact with the solder 46 on the surface thereof. The upper electrode 45 is electrically connected to the wiring 53 on the COF 50 via the solder 46 and connected to the driver IC 54, and the potential between the ground potential and the predetermined potential (for example, 20V) is low. Can be switched. Note that the connection terminals (not shown) of the intermediate electrode 44 and the lower electrode 43 described above are also electrically connected to the wiring via the solder 46 in the same manner as the upper electrode 43.

  In addition to the upper electrode 45, the connection terminal portion 45 a and the external electrode 47, a circular alignment mark 48 in a plan view used for alignment with the COF 50 is printed on the surface of the piezoelectric layer 42. The alignment marks 48 are each formed in a circular shape in plan view at the center of both side edges along the scanning direction of the piezoelectric actuator 23. Since the alignment mark 48 is formed of the same Ag—Pd conductive material as the electrodes 43, 44, 45, it is printed on a piezoelectric ceramic material sheet to form the electrodes 43, 44, 45. It is formed by printing and baking at the same time in the process. The alignment mark 48 is arranged in a predetermined positional relationship with the upper electrode 45, and the positional relationship can be ensured with high accuracy by simultaneously printing (using the same mask).

In addition, the piezoelectric layer 42 described above is polarized in an upward direction in advance between the upper electrode 45 and the intermediate electrode 44, and the piezoelectric layers 41 and 42 are sandwiched between the upper electrode 45 and the lower electrode 43. The portion is polarized downward from the upper electrode 45 toward the lower electrode 43. A portion of the piezoelectric layer 41 sandwiched between the intermediate electrode 44 and the lower electrode 43 is polarized downward from the intermediate electrode 44 toward the lower electrode 43.
Here, the operation of the piezoelectric actuator 32 will be described. First, in the standby state before the piezoelectric actuator 32 performs the operation of ejecting ink, as described above, the lower electrode 43 and the intermediate electrode 44 are always held at the ground potential and the predetermined potential (for example, 20 V), respectively. In addition, the potential of the upper electrode 45 is previously held at the ground potential. In this state, the upper electrode 45 is at a lower potential than the intermediate electrode 44 and is at the same potential as the lower electrode 43.

  As a result, a potential difference between the upper electrode 45 and the intermediate electrode 44 is generated, and an upward electric field that is the same as the polarization direction is generated in a portion sandwiched between these electrodes of the piezoelectric layer 42, and this portion of the piezoelectric layer 42 is Shrink in the horizontal direction orthogonal to this electric field. As a result, so-called unimorph deformation occurs, and the piezoelectric layers 41 and 42 and the portion (active part) of the diaphragm 40 facing the pressure chamber 10 are deformed so as to protrude toward the pressure chamber 10 as a whole. In this state, the volume of the pressure chamber 10 is smaller than when the piezoelectric layers 41 and 42 and the diaphragm 40 are not deformed.

  When the piezoelectric actuator 32 is driven to eject ink, the potential of the upper electrode 45 is once switched to the predetermined potential and then returned to the ground potential. When the potential of the upper electrode 45 is switched to the predetermined potential, the upper electrode 45 becomes the same potential as the intermediate electrode 44 and at a higher potential than the lower electrode 43. Thereby, the contraction of the piezoelectric layer 42 is restored. At the same time, a potential difference is generated between the upper electrode 45 and the lower electrode 43, and a downward electric field that is the same as the polarization direction is generated in the portion sandwiched between these electrodes of the piezoelectric layers 41 and 42. This portion of 41, 42 contracts in the horizontal direction. Thereby, the portions of the piezoelectric layers 41 and 42 and the diaphragm 40 facing the pressure chamber 10 as a whole are deformed so as to protrude toward the opposite side of the pressure chamber 10, and the volume of the pressure chamber 10 increases. As a result, the pressure of the ink in the pressure chamber 10 decreases, and the ink flows from the manifold channel 11 into the pressure chamber 10.

  Thereafter, when the potential of the upper electrode 45 is returned to the ground potential, the portions facing the pressure chambers 10 of the piezoelectric layers 41 and 42 and the diaphragm 40 become convex toward the pressure chamber 10 as a whole as described above. The volume of the pressure chamber 10 becomes small. As a result, the pressure of the ink in the pressure chamber 10 rises, and the ink is ejected from the nozzle 15 communicating with the pressure chamber 10.

Further, when the piezoelectric actuator 32 is driven as described above, when the potential of the upper electrode 45 is switched from the ground potential to a predetermined potential, the portion of the piezoelectric layer 42 sandwiched between the upper electrode 45 and the intermediate electrode 44 is Since the portion sandwiched between the upper electrode 45 and the lower electrode 43 of the piezoelectric layers 41 and 42 contracts simultaneously with the expansion from the contracted state to the state before contraction, the above-described expansion of the piezoelectric layer 42 causes the piezoelectric layers 41 and 42 to 42 is partly absorbed by the above contraction.
On the other hand, when the potential of the upper electrode 45 is returned from the predetermined potential to the ground potential, the portion sandwiched between the upper electrode 45 and the intermediate electrode 44 of the piezoelectric layer 42 contracts and the upper electrode 45 of the piezoelectric layers 41 and 42 contracts. The portion sandwiched between the piezoelectric layer 42 and the lower electrode 43 expands to a state before contraction, so that the contraction of the piezoelectric layer 42 is partially absorbed by the expansion of the piezoelectric layers 41 and 42.

  From the above, the deformation of the portion of the piezoelectric layers 41, 42 facing the pressure chamber 10 is transmitted to the portion facing the other pressure chamber 10, and ink is discharged from the nozzle 15 communicating with the other pressure chamber 10. So-called crosstalk, in which the characteristics fluctuate, is suppressed.

  Note that a potential difference is always generated in the portion between the intermediate electrode 44 and the lower electrode 43 of the piezoelectric layer 41 during the standby state and while the piezoelectric actuator 32 is being driven. Has an electric field in the same direction as the polarization direction. Thereby, this portion of the piezoelectric layer 41 is always contracted. The configuration and driving method of the actuator can be applied to the present invention as long as the pressure for discharging the ink filled in the pressure chamber from the nozzle can be applied.

  Next, the COF 50 (wiring member) that applies a potential to the piezoelectric actuator 32 will be described. The COF 50 includes a base material (flexible layer) 51, a plurality of lands 52 (conductive layers / joining portions), a plurality of wirings 53 and 53z, a driver IC 54, and a protective layer 55. The COF 50 is disposed above the piezoelectric actuator 32 and connected thereto. And pulled out in the scanning direction. And the base material 51 is connected to the peeling prevention board 100 mentioned later through the contact bonding layer 59. FIG.

  The base material 51 is made of a resin material having transparency such as polyimide, and has a strip shape having insulation and flexibility, and has a larger linear expansion coefficient than the piezoelectric material. The wiring 53 is formed of a conductive material such as copper on the substrate 51 by printing or the like. The substrate 51 is disposed on the piezoelectric actuator 32 with the surface (lower surface) on which the wiring 53 is formed facing the piezoelectric layer 42. The A protective layer 55 that protects the wiring 53 covers the surface on which the wiring 53 is formed. The driver IC 54 incorporates a drive circuit for supplying a drive signal to be applied to the piezoelectric actuator 32, and is arranged on the upper surface of the portion where the COF 50 is drawn. The driver IC 54 is connected to an input wiring 53z for inputting a driving signal from the printer on the main body side and an output wiring 53 for outputting a driving signal from the driver IC 54 to each electrode 43.

  The land 52 is disposed in a portion overlapping the connection terminal portion 45a in a plan view of the surface of the base member 51 facing the piezoelectric layer 42, and contacts the solder 46 when the piezoelectric actuator 32 and the COF 50 are connected to each other and an electrical connection point. Become. The land 52 is provided at the end of a plurality of output wirings 53 extending from the driver IC 54 and is connected to the driver IC 54. Although not shown, wiring and lands connected to the intermediate electrode 44 and the lower electrode 43 are wired to the COF 50 without passing through the driver IC 54. The driver IC 54 formed on the upper surface of the substrate 51 opposite to the piezoelectric layer 42 and the wiring 53 formed on the lower surface of the substrate 51 are connected through a through hole (not shown) formed in the substrate 51. Connected.

  The COF 50 is arranged with the surface of the base 51 on which the land 52 and the wiring 53 are formed facing the piezoelectric layer 42, and a protective layer 55 such as a solder resist covering the wiring 53 is formed on the surface. . The land 52 is configured such that the wiring 53 is exposed to the piezoelectric layer 42 side by opening the protective layer 55 on the piezoelectric layer 42 side by etching or the like at a position facing the external electrode 47 on the piezoelectric layer 42. The land 52 is formed by opening the protective layer 55 so that the land 52 has a larger area in plan view than the external electrode 47 and a larger area in plan view than the protrusion 101 of the peeling prevention plate 100 described later.

  The land 52 is formed on the convex electrode 52 protruding toward the piezoelectric layer 42 in the manufacturing process described later. (In the following description, the land 52 is referred to as the convex electrode 52, and the description will be supplemented as appropriate when it is necessary to use it properly.) As shown in FIG. 8, the convex electrode 52 is a first convex electrode portion. 52a and a second convex electrode portion 52b having a smaller protruding amount than that, and are formed in a concavo-convex shape having a gently continuous slope. That is, the tip end of the convex electrode 52 becomes the first convex electrode portion 52a. Then, the solder 46 arranged on the second convex electrode portion 52b side in the sectional view is melted and electrically and mechanically joined to the external electrode 47 of the piezoelectric layer 42, and the piezoelectric actuator 32 and the COF 50 are connected. It is joined. The protective layer 55 is provided with a distance between the piezoelectric layer 42 and the lower surface of the COF 50 at a portion other than the portion where the convex electrode portion 52 is opened to the piezoelectric layer 42 side. Do not touch.

  As shown in FIG. 2, the COF 50 is provided with alignment marks 58 used for alignment with the piezoelectric actuator 32 at the center of both side edges parallel to the direction in which the substrate 51 is pulled out. The alignment mark 58 is formed of a conductive material in a circular shape that is slightly smaller than the circular shape of the alignment mark 48 of the piezoelectric actuator 23, and is etched simultaneously with the formation of the conductive wire 53, so that the land 52 and the predetermined mark are formed. It is arranged in the positional relationship. At the position where the alignment mark 58 is provided, the protective layer 55 is removed with an area slightly larger than the alignment mark 548 of the piezoelectric actuator 23, and the alignment mark 58 is exposed on the upper surface.

In addition, in the inkjet head 3, a peeling prevention plate 100 (a plate-like body) is disposed on the upper surface of the substrate 51 of the COF 50. Since the COF 50 joined to the piezoelectric actuator 32 is easily subjected to mechanical force by an operator such as an operation of mounting the ink jet head 3 in the carriage in a later process, the connection portion with the COF 50 on the outer peripheral edge of the piezoelectric actuator 32 May easily peel off, and the connecting portion between the solder 46 and the land 52 may be peeled off to cause an electrical disconnection. Therefore, the peeling of the COF 50 is suppressed by bonding the peeling preventing plate 100 of the COF 50 onto the base material 51.
The peeling prevention plate 100 is a plate material such as a substantially rectangular ABS resin or a PBT / ABS polymer alloy having a substantially the same area as the piezoelectric actuator 32 in a plan view and long in the paper feed direction. A through-hole portion 108 for alignment provided for aligning the COF 50 and the piezoelectric actuator 32 is notched in the center portion. The through portion 108 may be formed as a hole instead of a notch.

  The lower surface (opposing surface) 100c of the peeling prevention plate 100 of the present invention is disposed so as to oppose the surface (the other surface) opposite to the wiring side surface (one surface) of the substrate 51, and the opposing surface 100c. The plurality of protruding portions 101 are formed so as to protrude toward the base material 51 side. The plurality of protruding portions 101 are disposed at positions facing the plurality of external electrodes 47 of the piezoelectric actuator 23 on the facing surface 100 c of the peeling prevention plate 100. That is, the same number of the plurality of protruding portions 101 is provided on the adhesive surface of the peeling prevention plate 100 with the base material 51 corresponding to the positions of the plurality of external electrodes 47 and the lands 52 (see FIG. 5). The through portion 108 of the peeling prevention plate 100 is formed with a predetermined positional relationship with respect to the protruding portion 101.

  The protrusion 101 is substantially circular in a plan view, and the first protrusion 101a and the second protrusion 101b are integrated in a cross-sectional view, and has a concavo-convex shape having a gently continuous slope (see FIG. 8). The first protruding portion 101a is formed such that the protruding amount from the flat surface on the base material 51 side of the peeling prevention plate 100 to the base material 51 side is higher than that of the second protruding portion 101b. Yes. The protruding portion 101 is also formed of ABS resin, PBT / ABS polymer alloy, conductive adhesive, etc., and is integrally formed on the peeling prevention plate 100 by pressing or aligned with the peeling prevention plate 100 by a dispenser or the like. And then bonded. The land 52 has a large area in plan view so that the width W1 of the protrusion 56 is smaller than the width W2 of the external electrode, and the width W2 of the external electrode is smaller than the width W3 of the land 52.

  Further, as shown in FIG. 5, the protruding portion 101 has a first protruding portion 101 a having a large protruding amount opposed to the pressure chamber 10 in the piezoelectric actuator 32 in a sectional view at the connection terminal portion 45 a of the piezoelectric actuator 23. The piezoelectric layer is disposed so as to be on the deformed portion (active portion) side, and the second projecting portion 101b is disposed on the opposite side to the active portion in the scanning direction.

  In the manufacturing process of the inkjet head 3 to be described later, the peeling prevention plate 100 is overlapped with the surface on which the protruding portion 101 protrudes facing the upper surface of the substrate 51, and the protruding portion 101 is overlapped with the opposing substrate 51. While pressing from the upper surface side to make direct contact, the facing portion of the base material 51 is bent and deformed, and on a flat surface that does not face the protruding portion 101, the gap between the upper surface of the base material 51 and the peeling prevention plate 58. The wiring unit 150 joined by the adhesive 59 filled in is formed. The adhesive 59 is a general-purpose adhesive such as an adhesive sheet. That is, in the wiring unit 150, the flat surface of the peeling prevention plate 100 is bonded and fixed to the upper surface of the base material 51, and the base material 51 protrudes on the opposite side (piezoelectric layer 23 side) from the peeling prevention plate 100. A convex electrode 52 having a portion 101 is provided.

  Since the convex electrode 52 is formed following the shape of the protruding portion 101, the convex electrode 52 includes the first protruding electrode portion 52a and the second protruding portion corresponding to the first protruding portion 101a. The second convex electrode portion 52b corresponding to the portion 101b is provided, and the first convex electrode portion 52a has a larger protruding amount toward the piezoelectric layer 23 than the second convex electrode 52b. . And the 1st convex electrode part 52a is arrange | positioned at the active part side in the connection terminal part 45a, and the 2nd convex electrode part 52b is arrange | positioned in the scanning direction and the other side. Further, as shown in FIG. 8, when the second convex electrode portion 52b is bonded to the piezoelectric layer 42 because the projection amount is lower than that of the first convex electrode portion 52a, the first convex electrode is formed. When the portion 52a comes into contact with the external electromotive force 47, a space A that can hold the solder 46 therein can be formed between the second convex electrode portion 52b.

  The wiring unit 150 having the convex electrode 52 and the piezoelectric layer 42 are bonded by thermocompression bonding, the first convex electrode portion 52a is in contact with the external electrode 47, and the second convex shape. The molten solder 46 disposed on the land portion 52b flows along a gentle slope, is held in the space A, and is hardened to be joined together.

  Since the convex electrode 52 of the wiring unit 150 includes the core portion 101, the convex electrode 52 is not excessively crushed by the pressing during bonding with the piezoelectric actuator 23. Can be joined with a certain distance between them. In addition, the wiring unit 150 is joined to the piezoelectric actuator 23 in a state where the peeling prevention plate 100 that is more rigid than the base material 51 is joined.

  Therefore, for example, in the conventional case, the base material 51 of the COF 50 is bent toward the piezoelectric layer 42 side by heat at the time of thermocompression bonding, and the piezoelectric layer 42 is touched and damaged, thereby inhibiting the driving of the actuator 32. It is prevented. Even when an unexpected impact or pressing force is applied to the inkjet head 3 in an assembly process such as when the inkjet head 3 is mounted on the carriage 2, the space between the piezoelectric layer 42 and the base material 51 remains. In addition to being widened, since the peeling prevention plate 100 is disposed on the base material 51, the piezoelectric layer 42 can be prevented from being damaged.

  Next, a method for manufacturing the inkjet head 3 will be described. FIG. 7 is a process diagram showing the manufacturing process of the inkjet head 3. In FIG. 7, in order to make the drawing easy to understand, the length in the left-right direction is drawn with respect to the length in the vertical direction. Prior to FIG. 7A, a laminated body of the flow path unit 31 and the piezoelectric actuator 23 is formed in advance. Specifically, the flow path unit 31 and the piezoelectric actuator 23 have an adhesive sheet (not shown) attached to the entire lower surface (the wide surface facing the pressure chamber 10) of the piezoelectric actuator 23, and then The piezoelectric actuator 23 is bonded and fixed to the flow path unit 31 so that the electrode 45 corresponds to each pressure chamber 10 in the flow path unit 31. Thereby, a laminated body of the flow path unit 31 and the piezoelectric actuator 23 is formed. And the manufacturing method demonstrated based on FIG. 7 below is made | formed with respect to this laminated body, However, In FIG. 7, description of the flow-path unit 31 is abbreviate | omitted.

  First, as shown in FIG. 7A, the protruding portion 101 is formed in advance on the resin peeling prevention plate 100. At this time, the protrusion 101 is integrally formed by pressing or the like on a plate-like member formed of an ABS resin material that is a material of the peeling prevention plate 100, and the first protrusion 101a and the second protrusion having a height lower than the first protrusion 101a. It is formed to have a concavo-convex shape having a portion 101b. In addition, the protrusion part 101 should just be a material with high hardness with respect to the base material 51 of COF50. Further, the protruding portion 101 may be aligned and applied to the plate-like member by a dispenser or a discharge device. Further, a notch 50a for alignment when laminating on the COF 50 is formed in the central portion on both short sides of the peeling prevention plate 100. (Plate-shaped member forming process)

  On the other hand, in FIG. 7B, an opening wider than the external electrode 47 is formed by etching at a position corresponding to the external electrode 47 on the side where the protective layer 55 covering the wiring of the base material 51 of the COF 50 is formed. Then, the land portion 52 is formed by exposing the wiring. Then, the solder 46 is accurately arranged by a plating method in a region corresponding to the second protrusion 101b of the peeling prevention plate 100 by the mask. (Conductive material placement process)

  Then, as shown in FIG. 7C, after the adhesive sheet 59 is adhered to the surface of the substrate 52 opposite to the wiring side, the peeling prevention plate 100 having the protrusions 100 formed thereon is protruded. The surface on which the portion 100 is formed is overlaid on the surface of the base member 52 opposite to the surface on the wiring side, the alignment mark 58 and the through hole 108 are aligned, and the land 52 and the protruding portion 100 face each other. After the peeling prevention plate 100 and the COF 50 are aligned, the two are laminated. At this time, while pressing the protruding portion 101 toward the base material 51 by a pressing means (not shown), the flat surface on the protruding portion 101 side of the peeling prevention plate 100 and the flat surface on the opposite side to the wiring side of the base material 52. When pressed so as to be bonded to the surface, the protruding portion 101 is harder than the flexible base material 52, so that it is pressed in the surface direction on the wiring side to bend and deform to protrude toward the wiring side. Since the land portion 52 of the base material 51 is formed in W3 wider than the width W1 of the protruding portion 101, the land portion 52 bends and deforms along with the deformation of the base material 51 as the base material 51 is deformed. In order to securely cover the deformed portion, the deformed portion is deformed into a gentle protrusion having a skirt. Then, since the adhesive sheet 59 is cured in such a state, the convex electrode 52 protruding toward the wiring side in a state where at least the tip portion is covered with the land portion 52 is formed. At this time, since the convex electrode 52 is deformed against the shape of the protruding portion 101, the first convex electrode portion 52a and the second convex electrode portion 52b are connected to the first protruding portion 101a and the second protruding electrode 101b. It is formed corresponding to the protrusion 101b. (Convex electrode forming step)

  The land 52 only needs to have at least an area that can form the first convex electrode portion 52a at the tip portion that comes into contact with the external electrode 47 in a later step when the land 52 becomes the convex electrode portion 52. As shown in FIG. 8, it is desirable to have an area that gently protrudes from the base. Further, since the solder 46 is disposed in a region corresponding to the second protruding portion 101b, the solder 46 is disposed on the second convex electrode portion 52b. In addition, the peeling prevention plate 100 is bonded and fixed to the back side of the COF 50, and the wiring unit 150 having the convex electrode 52 on the wiring side is formed. (FIG. 7D / Wiring unit forming process)

  As shown in FIG. 7E, the side where the convex electrode 52 of the wiring unit 150 protrudes from the laminated body of the flow path unit 31 and the piezoelectric actuator 23 and the external electrode 47 of the piezoelectric actuator 23 are arranged. The through hole 108, the alignment mark 58, and the alignment mark 48 are aligned so that the convex electrode 52 and the external electrode 47 are opposed to each other. The wiring unit 150 is overlapped.

  At this time, the alignment mark 58 of the COF 50 and the alignment mark 48 of the piezoelectric actuator 23 are aligned. In the region including the alignment mark 58, the peeling prevention plate 100 is provided with a through portion 108. , The protective layer 55 of the COF 50 is removed, and the base material 51 has translucency, so that as shown in FIGS. When viewed, not only the alignment mark 58 of the COF 50 but also the alignment mark 48 of the piezoelectric actuator 23 can be visually recognized through the substrate 51.

  Since the alignment mark 48 of the piezoelectric actuator 23 has a larger circular shape than the alignment mark 58 of the COF 50 positioned on the upper side, these centers can be easily overlapped with the land 52 of the COF 50 with high accuracy. The external electrode 47 of the piezoelectric actuator 23 can be aligned. Therefore, the convex electrode 52 previously formed on the COF 50 can correspond to the position of the external electrode 47. Note that the marks 48 and 55 may be respectively imaged by a camera and enlarged and displayed on the image display device to be aligned, or the marks 48 and 55 may be aligned by image processing.

  Returning to FIG. 7E, the heating and pressing means H (for example, a bar heater) is applied from above the peeling prevention plate 100 of the wiring unit 150 toward the piezoelectric actuator 23 to apply pressure and heat. At this time, the heat of the bar heater H is transmitted to the convex electrode 52 of the COF 50 through the protruding portion 101 of the peeling prevention plate 100, and the solder 46 disposed on the second convex electrode portion 52b is melted. At this time, the first convex electrode portion 52 a is in direct contact with the external electrode 47, and the second convex electrode portion 52 b having a lower protrusion amount forms a space A between the first convex electrode portion 52 a and the external electrode 47. ing. The melted solder 46 reaches the outer electrode 47 along the gentle slope from the second convex electrode portion 52a, is held in the space A, and the first convex electrode 52a and the external electrode 47 are in contact with each other. The state can be fixed by alloying with the molten solder 46. Therefore, the wiring unit 150 and the piezoelectric actuator 23 are joined electrically and mechanically. (FIG. 7 (f) (connection process))

  In the plate-like member forming step, the protruding portion 100 is arranged such that the first protruding portion 101a having a large protruding amount is on the active portion side in the sectional view in the connection terminal portion 45a of the piezoelectric actuator 23. The second protruding portion 101b is arranged so as to be opposite to the active portion in the scanning direction. Corresponding to this positional relationship, in the protruding electrode forming step, the first protruding electrode portion having a large protruding amount is provided. 52a is formed on the active part side, and a second convex electrode part 52b smaller than that is formed on the side opposite to the active part in the scanning direction. And the solder | pewter 46 is arrange | positioned on the 2nd convex-shaped electrode part 52b.

  In the conductive disposing step, the solder 46 may be disposed by applying a solder paste to the second convex electrode portion 52 with a dispenser after the convex electrode 52 is formed. Therefore, in such joining of the wiring unit 150 and the piezoelectric actuator 23, the solder 46 is disposed on the second convex electrode portion on the side opposite to the active portion side, so that the molten solder 46 is the first. It is blocked by the convex electrode portion 52a and cannot enter the active portion side. Even if the connecting terminal portion 45a and the upper electrode 45 are joined using a solder material that is familiar to the connection terminal portion 45a, it does not spread to the active portion side, so that inhibition of the active portion due to solder can be suppressed.

  Moreover, since the land 52 forms the convex electrode 52 as compared with the conventional case where the solder bump is formed on the flat land portion, the amount of solder for forming the solder bump may be reduced. it can. In general, the protruding electrode of the present invention has a first protruding electrode portion 52a and a second protruding electrode portion 52b having a protruding amount lower than that of the electrode formed in one protruding shape. A space A narrower than the gap between the piezoelectric layer 42 and the COF is formed between the external electrode 47 and the solder disposed on the second convex electrode portion 52b is melted by the capillary force generated in the space A. Is held in the space A with the external electrode 47. Therefore, compared to the case of applying and bonding a meltable conductive material such as solder to a general protruding electrode, it can be held in the space A even with a small amount of solder. It is possible to ensure the bonding between the external electrode and the protruding electrode. Further, since the convex electrode 52 has the core portion 101, even if a pressing force is applied at the time of joining, the convex electrode 52 can maintain its shape, and thus a space formed between the external electrode 47 and the convex electrode 52. Since A can also hold the region, the solder 46 can be kept in the space A even if the pressing force at the time of joining is more than necessary.

  Furthermore, in the present invention, since the solder 46 is disposed on the second convex electrode side opposite to the active portion in the scanning direction, the amount of solder is blocked by the first convex electrode portion. The solder 46 melted to the active part side due to variations in the active part does not wrap around, and the risk of obstructing the active part is reduced.

  In particular, in the piezoelectric actuator 12 in which the vibration plate 40 and the piezoelectric layers 41 and 42 are unimorph-deformed as described above, when a normal solder bump is used, a solder flow is generated by the molten solder, and the piezoelectric layer Curing above inhibits the deformation of the piezoelectric layer and greatly impedes the ejection drive of ink from the nozzle 15. However, according to the present invention, the solder bump is formed on the land portion as in the prior art. Can be joined with a small amount of solder, and since there is less risk of wrapping around the active part and obstructing the active part, it is electrically mechanical even for thin piezoelectric actuators as described above In particular, it is possible to perform solder bonding with stable bonding. Furthermore, since the amount of solder can be reduced, the solder flow is prevented, and the stress applied to the piezoelectric layer side when the solder is cured is small, so that there is little risk of peeling such as cracks even in thin actuators. .

  In addition, since the convex electrode having a core is joined in a shape that retains its shape, a distance can be gained between the piezoelectric layer and the COF. In addition, before aligning the COF with the piezoelectric actuator, Since the peeling prevention plate having higher rigidity than this is fixed to the COF, the risk of damaging the piezoelectric layer can be suppressed. In addition, since the COF alone has a thin film shape and low rigidity, it has disadvantages that handling in the alignment process and workability are poor. However, before aligning the COF with the piezoelectric actuator, Since the peeling prevention plate having higher rigidity than this is fixed, it is possible to easily work while keeping the COF in a flat state, and the working time can be shortened.

  In the present embodiment, the peeling prevention plate 100 having the protruding portion has been described by taking a plate material for preventing the peeling of the COF 50 as an example. However, for example, when it is desired to further increase the rigidity of the COF, this plate-like member is used. May be made of a metal rigid material, and in order to improve the thermal uniformity, it is formed of a material having excellent thermal conductivity to disperse local heat generation. It may also serve as a hot plate. In addition, it may also serve as a vibration suppression plate for suppressing the possibility of crosstalk due to vibration during driving of the piezoelectric actuator.

  In the present invention, the convex electrode is formed at a position corresponding to the plurality of external electrodes 47 so as to be a plurality of driving electrodes for driving the piezoelectric actuator. For example, a dummy convex electrode may be formed along the outer peripheral edge of the drive electrode, or a reinforcing dummy convex electrode for protecting the drive electrode portion may be used.

  In the present embodiment, the piezoelectric actuator 32 applies pressure to the ink in the pressure chamber 10 by so-called unimorph deformation, but is not limited thereto. For example, a plurality of piezoelectric layers polarized in the thickness direction are stacked on the pressure chamber, and by generating an electric field in the thickness direction on these piezoelectric layers, the piezoelectric layer is expanded in the thickness direction, The present invention can also be applied to a piezoelectric actuator that applies pressure to the ink in the pressure chamber 10 by deformation different from unimorph deformation, such as a piezoelectric actuator that applies pressure to the ink in the ink 10.

  In the above description, an example in which the present invention is applied to an ink jet head that discharges ink from a nozzle by applying pressure to ink in a pressure chamber and a piezoelectric actuator used in the ink jet head has been described. However, the present invention can also be applied to a liquid ejecting apparatus that ejects or transports liquid other than ink, and a piezoelectric actuator used in such a liquid transport apparatus. The present invention can also be applied to piezoelectric actuators used for purposes other than applying pressure to the liquid in the pressure chamber.

32 Piezoelectric actuators 41 and 42 Piezoelectric layer 45 Upper electrode 45a Connection terminal 46 Conductive material 52 Land 52a First convex electrode portion 52b Second convex electrode portion 55 Adhesive 50 COF
51 Base material 100 Plate-like body 101 Protruding part 101a First projecting part 101b Second projecting part

Claims (11)

A plate-like member having a protrusion on one surface;
An insulating flexible layer joined to the one surface of the plate-like member,
In the insulating flexible layer, a conductive layer is formed in a region corresponding to the protruding portion on the surface opposite to the plate-like member,
In the insulating flexible layer, the region where the conductive layer is formed is pressed by the protruding portion of the plate-like member and protrudes to the opposite side of the plate-like member, so that at least the tip is the conductive layer. A wiring unit comprising a covered convex electrode.   The protrusion has a first protrusion and a second discharge portion whose protrusion is smaller than the first protrusion, and the convex electrode corresponds to the first protrusion. The wiring unit according to claim 1, further comprising: one convex electrode portion and a second convex electrode portion corresponding to the second projecting portion. A plate-like member having a protruding portion on one surface; and an insulating flexible layer bonded to the one surface of the plate-like member, wherein the insulating flexible layer is a surface opposite to the plate-like member. A conductive layer is formed in a region corresponding to the projecting portion in the insulating flexible layer, and the region where the conductivity is formed is pressed by the projecting portion of the plate-shaped member in the insulating flexible layer. And a wiring unit in which a convex electrode whose tip is covered with the conductive layer is formed,
A flow path unit in which a liquid flow path including a pressure chamber communicating with the nozzle is formed;
A surface corresponding to the active portion on the surface of the piezoelectric layer in the outermost layer, the active portion having a plurality of piezoelectric layers, facing the pressure chamber and applying a discharge pressure to the liquid in the pressure chamber; A piezoelectric actuator having electrodes,
In the wiring unit, the tip of the convex electrode is joined to the surface electrode of the piezoelectric actuator via a conductive material. The protruding portion has a first protruding portion and a second protruding portion whose protruding amount is smaller than that of the first protruding portion, and the protruding electrode corresponds to the first protruding portion. 1 convex electrode portion and a second convex electrode portion corresponding to the second protruding portion,
4. The liquid droplet ejection head according to claim 3, wherein at least the second convex electrode portion of the convex electrode is joined to the surface electrode through the conductive material. 5. The surface electrode includes a main electrode portion corresponding to the active portion, and a connection terminal portion formed extending from the main electrode portion,
The convex electrode is arranged at a position facing the connection terminal portion, with the first convex electrode portion facing the active portion, and the second protruding electrode portion is separated from the active portion. The liquid droplet ejection head according to claim 4, wherein the liquid droplet ejection head is disposed. An insulating flexible layer forming step of forming an insulating flexible layer having a conductive layer formed on one surface thereof;
A plate-like member forming step of forming a plate-like member having higher rigidity than the insulating flexible layer having a protrusion on one surface thereof;
The plate-like member and the insulating flexible layer are overlapped with the surface on which the conductive layer is formed facing away from the plate-like member and corresponding to the conductive layer and the protruding portion. In this way, the insulating flexible layer is formed by fixing the insulating flexible layer, which is formed by projecting and deforming the region where the conductive layer is formed, to the plate-like member. A convex electrode forming step of forming a convex electrode having at least a tip covered with the conductive layer;
A method for manufacturing a wiring unit comprising: In the plate-like member forming step, the protruding portion is formed having a first protruding portion and a second protruding portion whose protruding amount is smaller than that of the first protruding portion,
In the convex electrode forming step, the convex electrode is formed by a first convex electrode portion corresponding to the first protruding portion and a second convex electrode corresponding to the second protruding portion. The method of manufacturing a wiring unit according to claim 6. A flow path unit in which a liquid flow path including a pressure chamber communicating with a nozzle is formed; and an active portion that opposes the pressure chamber and applies discharge pressure to the liquid in the pressure chamber. A head body including a piezoelectric actuator having a surface electrode corresponding to the above and a wiring unit bonded to the piezoelectric actuator;
The wiring unit,
An insulating flexible layer forming step of forming an insulating flexible layer having a conductive layer formed on one surface thereof;
A plate-like member forming step of forming a plate-like member having higher rigidity than the insulating flexible layer having a protrusion on one surface thereof;
The plate-like member and the insulating flexible layer are overlapped with the surface on which the conductive layer is formed facing away from the plate-like member and corresponding to the conductive layer and the protruding portion. In this way, the insulating flexible layer is formed by fixing the insulating flexible layer, which is formed by projecting and deforming the region where the conductive layer is formed, to the plate-like member. A convex electrode forming step of forming a convex electrode having at least a tip covered with the conductive layer;
Formed by and
Thereafter, a connection step of joining the tip of the convex electrode to the surface electrode of the piezoelectric actuator via a conductive material is performed.   After the conductive layer forming step and before the convex electrode forming step, the conductive layer is provided with a conductive material in a region to be the second convex electrode portion in the convex electrode forming step. The method for manufacturing a droplet discharge head according to claim 8, further comprising: a conductive material arranging step of arranging the conductive material.   The conductive material disposing step of disposing a conductive material on the second convex electrode portion after the convex electrode forming step and before the connecting step. Manufacturing method of a liquid droplet discharge head. The surface electrode includes a main electrode portion corresponding to the active portion and a connection terminal portion formed to extend from the main electrode portion, and in the connection step, the convex electrode faces the connection terminal portion. Connected at a position where
The said plate-shaped member formation process WHEREIN: It forms by arrange | positioning the said 1st protrusion part to the said active part side, and the said 2nd protrusion part away from the active part side, It forms. 11. A method for manufacturing a droplet discharge head according to any one of items 11 to 11.

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