JP2010105317A - Method for manufacturing flexible wiring member, flexible wiring member, method for manufacturing piezoelectric actuator unit, and piezoelectric actuator unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a flexible wiring member in which a portion opposed to a connection terminal projects further than other portions so as not to cause crack or fissure between the connection terminal and a wiring. <P>SOLUTION: In order to manufacture a piezoelectric actuator unit 33, a recess 51b is formed on an upper surface of a flexible layer 51 in a COF (Chip On Film) 50, then a thermal contraction curing material 56 is stuck to the upper surface of the flexible layer 51 so as to cover the recess 51b. Next, the COF 50 is heated by a heater H while it is pressed toward a piezoelectric layer 42, so that a land 52 and a conductive bump 46 are electrically connected and also the COF 50 and the piezoelectric layer 42 are bonded. At such a time, a portion of the flexible layer 51 opposed to the land 52 becomes a swelling part 51a swelling to the piezoelectric layer 42 side according as the thermal contraction curing material 56 is contracted. The swelling part 51a formed in such a way is smoothly connected to a flat portion of the flexible layer 51 adjacent to the swelling part 51a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a flexible wiring member configured by forming wiring on a flexible layer, a wiring member, a method for manufacturing a piezoelectric actuator unit having such a flexible wiring member, and a piezoelectric actuator unit. .

  In Patent Document 1, a portion facing a terminal portion in a flexible printed board in which a conductive pattern is formed on the surface of a base film is a thin portion having a smaller thickness than the other portions, and the flexible printed board is further provided with a terminal portion. The flexible printed circuit board is pressed from the opposite side of the female mold by the male mold in a state where the punch is placed on the female mold so as to face the depression and the punch of the male mold faces the terminal part. By doing so, it is described that the part facing the terminal part of the base film is projected to the terminal part side to be a convex part.

JP 2006-7669 A

  However, if a convex portion is formed on the base film as described in Patent Document 1, a large load is applied to a portion between the portion where the convex portion of the base film is formed and the flat portion adjacent to the convex portion. Will be bent suddenly, and there is a risk of cracking or tearing between the terminal portion and the conductive pattern.

  An object of the present invention is to provide a method for manufacturing a flexible wiring member and a flexible wiring member in which a portion facing a connection terminal protrudes more than other portions and no crack or tear occurs between the connection terminal and the wiring. And the manufacturing method of a piezoelectric actuator unit which has such a flexible wiring member, and a piezoelectric actuator unit are provided.

  The manufacturing method of the flexible wiring member which concerns on 1st invention is formed in the insulating flexible layer, the wiring formed in one surface of the said flexible layer, and one surface of the said flexible layer, and is connected to the said wiring A method of manufacturing a flexible wiring member having a connection terminal, wherein a portion of the surface of the flexible layer opposite to the one surface that is opposite to the portion where the connection terminal is formed is heated. The connection terminal of the flexible layer is formed by heating and shrink-hardening the heat-shrink hardener bonded to the flexible layer, and a heat-shrink hardener bonding step for bonding the heat-shrink hardener that shrinks and hardens. And a raised portion forming step of forming a raised portion raised on the one surface side.

  According to this, the connection terminal of the flexible layer is formed by heating the heat shrink hardening material adhered to the portion facing the connection terminal on the surface opposite to the one surface of the flexible layer to shrink and heat the heat shrink hardening material. If a raised portion is formed on one surface of the flexible layer, the surface of the flexible layer is smoothly connected to the flat portion adjacent to the raised portion. Therefore, it is difficult for a crack or tear to occur between the connection terminal formed on the raised portion or between the connection terminal and the wiring.

  A method for manufacturing a flexible wiring member according to a second invention is a method for manufacturing a flexible wiring member according to the first invention, wherein the one surface of the flexible layer and The method further comprises a first recess forming step for forming a first recess in a part of the opposite surface to which the heat shrink hardening material is to be bonded, and in the heat shrink hardening material bonding step, the first recess The heat shrink hardening material is bonded so that a space is formed between the heat shrink hardening material and the heat shrink hardening material.

  According to this, when the heat shrink hardening material is heated, the flexible layer is deformed so as to fill the space formed between the heat shrink hardening material and the first recess, so that the flexible layer is raised on one surface side. And the height of the raised portion can be increased.

  The manufacturing method of the flexible wiring member which concerns on 3rd invention is a manufacturing method of the flexible wiring member which concerns on 1st or 2nd invention, Comprising: On the said one surface of the said flexible layer before the said protruding part formation process The method further includes a second recess forming step of forming a pair of second recesses so as to sandwich the portion where the connection terminal is formed.

  According to this, when the heat-shrinkable curing material is heated, the flexible layer is deformed so as to fill the second concave portion, so that the flexible layer is easily raised on one surface side, and the height of the raised portion is further increased. be able to.

  The manufacturing method of the flexible wiring member which concerns on 4th invention is a manufacturing method of the flexible wiring member which concerns on one of the 1st-3rd invention, Comprising: Before the said heat shrink hardening material adhesion process, the said flexible layer Forming a third recess having a depth substantially the same as the thickness of the heat-shrinkage-hardening material on the entire surface of the portion opposite to the one surface of the heat-shrinkage-hardening material. A heat shrinkage-hardening material adhering step, wherein the heat shrinkage-hardening material is bonded to the bottom surface of the third recess.

  According to this, since the heat shrink hardening material is disposed on the bottom surface of the third recess having the same depth as the thickness thereof, the surface opposite to the one surface of the flexible layer becomes flat, and the flexible wiring is made of versatile. It becomes a certain convenience.

  A method for manufacturing a flexible wiring member according to a fifth invention is a method for manufacturing a flexible wiring member according to any one of the first to fourth inventions, wherein the connection terminal is orthogonal to the one surface of the flexible layer. As seen from the direction in which the heat shrinkage hardening material extends, the heat shrinkage hardening material extends outward.

  According to this, since the connection terminal is formed on a smooth curved surface extending over the portion where the raised portion is formed on one surface of the flexible layer and the portion adjacent to the raised portion, the connection terminal is cracked or broken. Can be prevented. In addition, since a relatively large connection terminal and a wiring thinner than the connection terminal are connected in a flat portion of the flexible layer, it is possible to prevent a crack or a tear from occurring between the connection terminal and the wiring. Can do.

  A flexible wiring member according to a sixth aspect of the present invention includes a flexible layer, a wiring formed on one surface of the flexible layer, a connection terminal formed on the one surface of the flexible layer, and connected to the wiring. A protruding portion that is raised on the one surface side is formed in a portion of the flexible layer where the connection terminal is formed, and the protruding portion is formed on the one surface of the flexible layer. The portion and the flat portion adjacent to the raised portion are smoothly connected to each other.

  According to this, one surface of the flexible layer has a smooth connection between the portion where the bulge is formed and the flat portion adjacent to the bulge, so the connection terminal formed on the bulge, or the connection terminal Cracks and tears are less likely to occur between the wiring.

  A flexible wiring member according to a seventh invention is the flexible wiring member according to the sixth invention, wherein the flexible wiring member is bonded to a portion facing the connection terminal on the surface of the flexible layer opposite to the one surface. The heat-shrinkable and hardened material is further shrinkage-hardened, and the raised portion is formed by raising the flexible layer by shrinkage-hardening the heat-shrinkable and hardened material. It is what.

  According to this, the raised portion can be easily formed.

  A flexible wiring member according to an eighth aspect of the present invention is the flexible wiring member according to the seventh aspect of the present invention, wherein the connection terminal is more than the heat shrinkable hardening material when viewed from a direction orthogonal to the one surface of the flexible layer. Is also extended to the outside.

  According to this, since the connection terminal is formed on a smooth curved surface extending over the portion where the raised portion is formed on one surface of the flexible layer and the portion adjacent to the raised portion, the connection terminal is cracked or broken. Can be prevented. In addition, since a relatively large connection terminal and a wiring thinner than the connection terminal are connected in a flat portion of the flexible layer, it is possible to prevent a crack or a tear from occurring between the connection terminal and the wiring. Can do.

  According to a ninth aspect of the present invention, there is provided a piezoelectric actuator unit manufacturing method comprising: a piezoelectric layer having an active portion; and a piezoelectric actuator provided on the piezoelectric layer for generating an electric field in the active portion; An insulating flexible layer disposed so as to face the layer; and a wiring connected to the electrode and the piezoelectric layer of the flexible layer formed on a surface of the flexible layer facing the piezoelectric layer. A flexible wiring member formed on a surface facing the layer and having a first connection terminal connected to the wiring, and the surface facing the flexible layer of the piezoelectric layer includes the plurality of A second connection terminal connected to the electrode is formed, and the first connection terminal and the second connection terminal are connected to each other to connect the wiring and the electrode. A method of manufacturing a tuner unit, wherein the portion of the flexible layer opposite to the piezoelectric layer opposite to the portion where the first connection terminal is formed is heated and contracted and cured by heating. A heat shrinkage hardening material adhering step for bonding the material, and heating and shrinkage hardening of the heat shrinkage hardening material to oppose the piezoelectric layer to a portion of the flexible layer where the first connection terminal is formed. A raised portion forming step for forming a raised portion raised on the surface side, and a joining step for electrically connecting the first connection terminal and the second connection terminal and joining the flexible wiring member and the piezoelectric layer; It is characterized by having.

  According to this, the connection terminal of the flexible layer is formed by heating the heat shrink hardening material adhered to the portion facing the connection terminal on the surface of the flexible layer opposite to the piezoelectric layer to shrink the heat shrink hardening material. In the case where a raised portion is formed in the formed portion so as to protrude on the side of the flexible layer facing the piezoelectric layer, the surface facing the piezoelectric layer of the flexible layer is adjacent to the portion where the raised portion is formed and the raised portion. Since the flat portion is smoothly connected, the second connection terminal formed on the raised portion or the second connection terminal and the wiring are less likely to be cracked or torn.

  Moreover, since the raised part is formed in the flexible layer, a gap is formed between the piezoelectric layer and the flexible layer, and the flexible layer can be prevented from coming into contact with the piezoelectric layer.

  A method for manufacturing a piezoelectric actuator unit according to a tenth aspect of the present invention is to heat the flexible wiring member before the protruding portion is formed while pressing the flexible wiring member from the side opposite to the piezoelectric layer toward the piezoelectric layer. The protruding portion forming step and the joining step are performed at the same time.

  According to this, since the formation of the raised portion and the formation of the flexible layer and the piezoelectric layer can be performed simultaneously, the manufacturing process is simplified.

  A method for manufacturing a piezoelectric actuator unit according to an eleventh aspect of the invention is a method for manufacturing a piezoelectric actuator unit according to the tenth aspect of the invention, wherein the first connection terminal or the step is performed before the raised portion forming step and the joining step. A bump forming step of forming bumps on the second connection terminals is further provided.

  According to this, in the process of joining the flexible layer to the piezoelectric layer, it is possible to reliably prevent contact at a portion other than the portion where both are joined.

  A method of manufacturing a piezoelectric actuator unit according to a twelfth aspect of the invention is a method of manufacturing a piezoelectric actuator unit according to the eleventh aspect of the invention, wherein at least the surface of the flexible layer facing the piezoelectric layer is provided before the joining step. It further includes an adhesive layer forming step of forming a thermosetting adhesive layer in a portion where the connection terminal is formed, and in the joining step, the flexible layer is directed from the side opposite to the piezoelectric layer toward the piezoelectric layer. By heating while pressing, the adhesive layer penetrates the bump to connect the bump and the first connection terminal, and the piezoelectric layer and the flexible layer are bonded by the adhesive layer pushed out by the bump. It is characterized by joining the layers.

  According to this, since the flexible layer is prevented from coming into contact with the piezoelectric layer, the adhesive layer formed on the flexible layer adheres to the piezoelectric layer, and after heating, the flexible layer becomes the piezoelectric layer by the adhesive layer. It is possible to prevent the deformation from returning to its original state after being bonded to the adhesive layer, or the adhesive layer from remaining on the piezoelectric layer even when the deformation is restored.

  A method for manufacturing a piezoelectric actuator unit according to a thirteenth invention is a method for manufacturing a piezoelectric actuator unit according to any one of the ninth to twelfth inventions, wherein the flexible layer is formed before the heat shrink-hardening material adhering step. A first recess forming step of forming a first recess in a part of the surface of the surface opposite to the piezoelectric layer to which the heat shrink hardening material is to be bonded, The heat shrink-hardening material is bonded so that a space is formed between the first recess and the heat shrink-hardening material.

  According to this, since the flexible layer is deformed so as to fill the space formed between the heat shrink hardening material and the first recess when the heat shrink hardening material is heated, the flexible layer is opposed to the piezoelectric layer. It becomes easy to protrude to the side, and the height of the protruding portion can be increased.

  A method for manufacturing a piezoelectric actuator unit according to a fourteenth invention is a method for manufacturing a piezoelectric actuator unit according to any one of the ninth to thirteenth inventions, wherein the flexible layer is formed before the bulge forming step. The method further includes a second recess forming step of forming a pair of second recesses so as to sandwich the portion where the connection terminal is formed on the surface facing the piezoelectric layer.

  According to this, when the heat-shrinkable curing material is heated, the flexible layer is deformed so as to fill the second concave portion, so that the flexible layer is easily raised on the side facing the piezoelectric layer, and the height of the raised portion is increased. Can be further increased.

  A method for manufacturing a piezoelectric actuator unit according to a fifteenth aspect of the present invention is a method for manufacturing a piezoelectric actuator unit according to any of the ninth to fourteenth aspects of the present invention, wherein the flexible layer is formed before the heat shrink-hardening material adhering step. Forming a third recess having a depth substantially the same as the thickness of the heat-shrinkage-hardening material on the entire surface of the surface opposite to the piezoelectric layer to which the heat-shrinkage-hardening material is bonded. A heat shrinkage-hardening material adhering step, wherein the heat shrinkage-hardening material is bonded to the bottom surface of the third recess.

  According to this, since the heat shrink hardening material is disposed on the bottom surface of the third recess having the same depth as the thickness thereof, the surface opposite to the one surface of the flexible layer becomes flat, and the flexible wiring is made of versatile. It becomes a certain convenience.

  A manufacturing method of a piezoelectric actuator unit according to a sixteenth invention is a manufacturing method of a piezoelectric actuator unit according to any of the ninth to fifteenth inventions, wherein the connection terminal is formed by connecting the piezoelectric layer and the flexible layer. As viewed from the direction orthogonal to the stacking direction, the heat shrinkage hardening material extends to the outside.

  According to this, since the connection terminal is formed on a smooth curved surface extending over the portion where the raised portion is formed on one surface of the flexible layer and the portion adjacent to the raised portion, the connection terminal is cracked or broken. Can be prevented. In addition, since a relatively large connection terminal and a wiring thinner than the connection terminal are connected in a flat portion of the flexible layer, it is possible to prevent a crack or a tear from occurring between the connection terminal and the wiring. Can do.

  A manufacturing method of a piezoelectric actuator unit according to a seventeenth invention is a manufacturing method of a piezoelectric actuator unit according to any of the ninth to sixteenth inventions, wherein the piezoelectric actuator is opposite to the flexible layer of the piezoelectric layer. It further comprises a diaphragm bonded to the side surface.

  According to this, in the piezoelectric actuator that deforms the piezoelectric layer and the diaphragm in the thickness direction by deforming the piezoelectric layer in the surface direction by generating an electric field in the active portion (so-called unimorph deformation), the flexible layer However, the drive characteristics of the piezoelectric actuator will fluctuate because the flexible layer is prevented from contacting the piezoelectric layer. Can be prevented.

  A piezoelectric actuator unit according to an eighteenth aspect of the present invention is a piezoelectric actuator having a piezoelectric layer having an active part, an electrode provided on the piezoelectric layer for generating an electric field in the active part, and facing the piezoelectric layer. An insulating flexible layer disposed on the surface of the flexible layer facing the piezoelectric layer, the wiring connected to the electrode, and the piezoelectric layer of the flexible layer A flexible wiring member formed on an opposing surface and having a first connection terminal connected to the wiring, and the piezoelectric layer facing the flexible layer is connected to the electrode. And a second connection terminal connected to the first connection terminal is formed, and the portion of the flexible layer where the first connection terminal is formed includes A raised portion is formed on the side facing the electric layer, and the surface of the flexible layer has a smooth connection between a portion where the raised portion is formed and a flat portion adjacent to the raised portion. It is characterized by that.

  According to this, since the surface facing the piezoelectric layer of the flexible layer smoothly connects the portion where the raised portion is formed and the flat portion adjacent to the raised portion, the second connection formed on the raised portion. Cracks or tears are unlikely to occur between the terminal or the second connection terminal and the wiring.

  A piezoelectric actuator unit according to a nineteenth aspect of the present invention is the piezoelectric actuator unit according to the eighteenth aspect of the present invention, wherein the piezoelectric actuator unit is bonded to a portion facing the connection terminal on the surface of the flexible layer opposite to the piezoelectric layer. A plurality of heat-shrinkable and hardened materials that have been shrink-hardened, and the raised portion is formed by the flexible layer being raised by the heat-shrinkable and hardened material being shrink-hardened. It is characterized by.

  According to this, the raised portion can be easily formed.

  According to the present invention, the connection terminal of the flexible layer is obtained by heating the heat shrink hardening material adhered to the portion facing the connection terminal on the surface opposite to the one surface of the flexible layer to shrink and heat the heat shrink hardening material. When a raised part is formed on one surface side of the flexible layer, the surface where the raised part is formed and the flat part adjacent to the raised part are smooth on the surface of the flexible layer. Therefore, it is difficult for cracks or tears to occur between the connection terminals formed on the raised portions or between the connection terminals and the wiring.

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

  FIG. 1 is a schematic configuration diagram of a printer 1 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 (liquid transfer device), 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 inkjet head 3 is disposed on the lower surface of the carriage 2, and a plurality of nozzles are mounted on the lower 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. FIG. 2 is a perspective view showing the configuration of the inkjet head 3 of FIG. FIG. 3 is a plan view of the inkjet head 3. FIG. 4A is a partially enlarged view of FIG. FIGS. 4B to 4D are views showing the surfaces of a diaphragm 40 and piezoelectric layers 41 and 42, which will be described later, in FIG. FIG. 5 is a cross-sectional view taken along line VV in FIG. 6 is a cross-sectional view taken along line VI-VI in FIG.

  For easy understanding of the drawing, FIG. 2 shows a land 52 and a wiring 53 (described later) in a transparent state. 3 and FIG. 4, illustration of a part of the ink flow path of the flow path unit 31 described later is omitted, and illustration of the lower electrode 43 and the intermediate electrode 44 of the piezoelectric actuator 32 is omitted in FIG. ing. 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 FIGS. 2 to 6, the inkjet head 3 is disposed on the upper surface of 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, and the flow path unit 31. And a piezoelectric actuator unit 33 that applies pressure for discharging from the nozzle 15 to the ink filled in the pressure chamber 10. The piezoelectric actuator unit 33 includes a piezoelectric actuator 32 and a COF 50 (Chip On Film) (wiring member) electrically and mechanically connected on the upper surface thereof. 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 (liquid transfer flow) 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 from the pressure chamber 10. Road) is formed. As will be described later, when pressure is applied to the ink in the pressure chamber 10 by the piezoelectric actuator 32, 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.

  Then, among the five pressure chamber groups 7, black ink that is frequently used is ejected from the nozzles 15 corresponding to the pressure chambers 10 constituting the two on the right side in FIG. 3, and the three pressures on the left side in FIG. From the nozzles 15 corresponding to the pressure chambers 10 of the chamber group 7, yellow, cyan, and magenta inks are ejected 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 row of pressure chambers 10, and extends to a position where it overlaps the longitudinal direction of the pressure chambers 10 in plan view and communicates with the ink supply port 9.

  Next, the piezoelectric actuator 32 includes a vibration plate 40, piezoelectric layers 41 and 42, a lower electrode 43, an intermediate electrode 44, an upper electrode 45, a conductive bump 46 and a COF 50. 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 each other and disposed 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. .

  As shown in FIGS. 3 and 4D, the plurality of upper electrodes 45 are formed on the upper surface of the piezoelectric layer 42 (opposite surface to the COF 50) so as to correspond to the plurality of pressure chambers 10. Are arranged in the paper feed direction, form an upper electrode row group, and form an upper electrode 45 constituting a row of two upper electrodes 45 included in one upper electrode row group. They are arranged so as to be shifted from each other in the paper feeding direction. 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. The upper electrode 45 has a portion at the end opposite to the nozzle 15 in the scanning direction extending to a portion not facing the pressure chamber 10 in the scanning direction, and this portion is a connection terminal connected to the land 52 of the wiring 53 of the COF 50. 45a (first connection terminal). The connection terminal 45a is made of an Ag—Pd material.

  Further, the surface of the connection terminal 45a is made of a conductive material such as a metal (in this embodiment, a conductive material containing resin and containing Ag, such as NH-070A (T) manufactured by Nihon Solda Co., Ltd.) Conductive bumps 46 projecting upward from the surface of the terminal 45a are formed. Further, as will be described later, the upper electrode 45 is connected to the wiring 53 on the COF 50 via the conductive bump 46 and is connected to the driver IC 54 mounted with the COF 50, and the ground potential and the predetermined potential (for example, 20V), and the potential is 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 conductive bumps, similarly to the upper electrode 45.

  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.

  Next, the COF 50 (flexible wiring member) that applies a potential to the piezoelectric actuator 32 includes a flexible layer 51, a plurality of lands 52 (second connection terminals), a plurality of wirings 53 and 53 z, and a driver IC 54. The COF 50 is arranged and connected above the piezoelectric actuator 32 and is drawn out in the scanning direction.

  The flexible layer 51 is a band-shaped body made of a resin material such as polyimide and having insulating properties and flexibility, and has a linear expansion coefficient larger than that of the piezoelectric material. The flexible layer 51 is disposed on the piezoelectric actuator 32 with its lower surface facing the piezoelectric layer 42. Moreover, the flexible layer 51 has a raised portion 51 a that is raised on the piezoelectric layer 42 side in a plan view, and a portion facing the conductive bump 46.

  Here, a concave portion 51b (first concave portion) is formed in a portion facing the conductive bump 46 on the upper surface of the flexible layer 51, and a heat shrink hardening material 56 is adhered so as to cover the concave portion 51b. The raised portion 51a has a gap between the concave portion 51b and the portion facing the conductive bump 46 of the flexible layer 51 as the heat-shrinkable and hardened material 56 is heated and shrink-hardened in the manufacturing process of the piezoelectric actuator unit 33 described later. It is formed by deforming so as to fill up and projecting to the piezoelectric layer side. Examples of the heat shrinkable curing material include polyethylene and ethylene vinyl acetate copolymer. Further, since the raised portions 51a are formed in this way, the raised portions 51a and the flat portions adjacent to the raised portions 51a are smoothly connected on the lower surface of the flexible layer 51.

  The plurality of lands 52 are made of a conductive material such as copper, and extend from the raised portion 51a on the lower surface of the flexible layer 51 to a flat portion adjacent to the raised portion 51a. That is, it is continuously formed on a smooth curved surface extending over the raised portion 51a and a flat portion adjacent to the raised portion 51a. The wiring 53 is made of a conductive material such as copper, is formed on the lower surface of the flexible layer 51, and is connected to the plurality of lands 52 in a flat portion on the lower surface of the flexible layer 51.

  Here, unlike the present embodiment, when the flexible layer 51 is bent sharply at a portion between the raised portion 51a and the flat portion adjacent to the raised portion 51a, the land 52 is cracked at the bent portion. As a result, there is a risk that a crack or tear may occur between the land 52 and the wiring 53.

  However, in this embodiment, since the raised portion 51a and the flat portion adjacent to the raised portion 51a are smoothly connected on the lower surface of the flexible layer 51, the land 52 is prevented from being cracked or torn. As a result, it is possible to prevent a crack or tear from occurring between the land 52 and the wiring 53.

  Furthermore, in the present embodiment, since the land 52 and the wiring 53 thinner than the land 52 are connected to each other in a flat portion adjacent to the raised portion 51a, the land 52 and the wire 53 are connected to each other on the raised portion 51a. Compared with the case where it connects, it can prevent reliably that a crack and a tear will arise between the land 52 and the wiring 53. FIG.

  In addition, the flexible layer 51 and the piezoelectric layer 42 are joined by a thermosetting adhesive layer 55 at a portion facing the conductive bump 46 and the land 52. The adhesive layer 55 also extends to portions other than the portions facing the conductive bumps 46 and the lands 52 on the lower surface of the flexible layer 51 and is covered with the wiring 53. Note that the flexible layer 51 and the piezoelectric layer 42 are not joined to the adhesive layer 55 except for the portions facing the conductive bumps 46 and the lands 52.

  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 the output wiring 53 for outputting a driving signal to the electrodes 43 to 45, and is connected to an input wiring 53 z for inputting a driving signal from the main body side.

  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 set to the ground potential and the predetermined potential (for example, 20 V), respectively. In addition to being held, the potential of the upper electrode 45 is previously held at the ground potential. In this state, the upper electrode 45 has a lower potential than the intermediate electrode 44 and has 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 of the diaphragm 40 facing the pressure chamber 10 are deformed so as to be convex 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. As a result, the piezoelectric layers 41 and 42 and the diaphragm 40 are deformed so as to protrude to the opposite side of the pressure chamber 10 as a whole, and the volume of the pressure chamber 10 increases.

  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 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 the ink from the nozzle 15 communicating with the other pressure chamber 10 is transferred. So-called crosstalk, in which the ejection 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 are not limited to those in the above-described embodiment as long as the pressure for ejecting the ink filled in the pressure chamber from the nozzle can be applied.

  Next, a method for manufacturing the inkjet head 3 (piezoelectric actuator unit 33) will be described. FIG. 7 is a process diagram showing the manufacturing process of the inkjet head 3.

  To manufacture the inkjet head 3, first, as shown in FIG. 7A, the upper electrode in the laminate of the diaphragm 40, the piezoelectric layers 41 and 42, the electrodes 43 to 45, and the flow path unit 31 (not shown). Conductive bumps 46 are formed on the surface of the 45 connection terminals 45a by printing or the like (bump formation step). The conductive bump is formed of a conductive paste such as Ag containing resin.

  Further, in a step different from the step shown in FIG. 7A, as shown in FIG. 7B, a land 52 formed by printing or the like is formed on the lower surface of the flexible layer 51. Then, on the upper surface of the flexible layer 51, a recess 51b is formed by laser processing, etching, sandblasting, or the like in a portion facing the land 52 (part of a portion to which the heat shrinkable hardening material 56 is bonded). (1st recessed part formation process). The recess 51b has a V-shape that is opened upward and reduced in diameter in a cross-sectional view, and the outer shape in plan view is circular. Subsequently, as shown in FIG. 7 (c), the heat shrinkable hardening material 56 is applied so as to cover the recess 51b in a portion facing the land 52 on the upper surface of the flexible layer 51 and to create a space between the recess 51b. Adhere (heat shrinkage hardening material adhesion process). The heat shrink hardening material 56 has a substantially circular shape in plan view. Further, as shown in FIG. 7D, an adhesive layer 55 made of a thermosetting material such as a solder resist is formed on the lower surface of the flexible layer 51 so as to cover the land and the wiring (adhesive layer forming step). At this time, the adhesive layer 55 is adjusted to various conditions such as temperature, so that the adhesive layer 55 made of a thermosetting material is in an uncured (semi-cured) state that does not sag from the flexible layer 51. Keep it.

  Next, as shown in FIG. 7E, the COF 50 is aligned from the opposite side of the piezoelectric layer 42 by the heater H in a state where the land 52 and the conductive bump 46 are aligned in a plan view. Heat while pressing towards 42. Here, the heater H is a bar heater H having a smooth heating surface.

  As a result, the heat shrinkable hardening material 56 is heated to the temperature Ta ° C. by the heater H and contracts and hardens. Here, the temperature Ta is a temperature at which the heat-shrinkable material 56 can be shrink-cured and is lower than the curing temperature of the adhesive layer 55. The heat-shrinkable and hardened material 56 having a substantially circular shape in plan view tends to shrink toward the center direction (direction facing each other in the center in a cross-sectional view). At this time, the portion facing the land 52 of the flexible layer 51 to which the heat shrink hardening material 56 is bonded is flexible and has good adhesion to the heat shrink hardening agent 56, so that the heat shrink hardening agent 56 shrinks. Along with this, both are drawn in the contraction direction. Since the land portion has a recess, the heat-shrinkable hardened material shrinks in the central direction, and the opposing flexible layer is drawn, shrinking to fill the opening space of the recess, A flat portion adjacent to the raised portion 51a on the lower surface of the flexible layer 51 starts to bend and deform from the tip portion (portion opposite to the opening side) so as to escape to the lower surface side, and rises toward the piezoelectric layer 42 side. A raised portion 51a having a smooth surface connected to is formed. Since the heat shrink hardening material 56 is hardened in a contracted state, the raised portion 51a is maintained in a raised state. In the present proposal, since the concave portion is formed in a V shape in sectional view, the flexible layer is easily deformed from the tip portion to the lower surface side. At this time, since the land 52 is formed in close contact with the flexible layer 51, the raised portion 51 a having a gentle surface connected to the flat portion of the land 52 is formed along the raised portion 51 a of the flexible layer 51. ing. In this state, the conductive bump 46 penetrates through the uncured adhesive layer 55, comes into contact with the raised land 52 and is electrically connected thereto, and the adhesive pushed out by the penetration of the conductive bump 46. The agent layer 55 flows through the portion surrounding the conductive bump 46 and reaches the upper surface of the connection terminal 45 a of the piezoelectric layer 42. In this state, the heater layer H is heated to a temperature Tb ° C. to cure the adhesive layer 55, whereby the land 52 and the conductive bump 46 are electrically and mechanically connected, and the COF 50 and the piezoelectric layer. 42 is joined. Here, the temperature Tb ° C. is a temperature higher than the temperature Ta ° C. at which the adhesive layer 55 can be cured. In addition, since the conductive bump includes a resin and is formed of a conductive material including Ag, the conductive bump has elasticity enough to crush the tip portion, and further has a protrusion provided on the flexible layer. Since the land portion formed has elasticity, both the bumps and the tip of the raised portion are crushed by the mutual elastic force, so that the contact area can be increased and the reliability of electrical connection is improved. can do.

  That is, in the present embodiment, the ridge formation process and the bonding process according to the present invention are performed simultaneously by heating the COF 50 against the piezoelectric layer 42 by the heater H.

  Here, as described above, since the flexible layer 51 has a larger linear expansion coefficient than the piezoelectric layer 42, when the heater H that is a bar heater is pressed and heated toward the piezoelectric layer 42, the flexible layer 51 is more than the piezoelectric layer 42. As a result, the flexible layer 51 may bend toward the piezoelectric layer 42 and come into contact with the piezoelectric layer 42 to contaminate or damage the piezoelectric layer 42.

  Further, in the present embodiment, since the uncured adhesive layer 55 is formed on the entire lower surface of the flexible layer 51, if the flexible layer 51 comes into contact with the piezoelectric layer 42, the adhesive is in that state. When the layer 55 is cured and the heater H is released and the heating is stopped, the deformation of the flexible layer 51 may not be restored. Even if the deformation of the flexible layer 51 is restored, the adhesive layer 55 may remain on the surface of the piezoelectric layer 42. In these cases, the deformation of the piezoelectric layers 41 and 42 and the diaphragm 40 when the piezoelectric actuator 32 is driven as described above is hindered, and the ink ejection characteristics from the nozzles 15 fluctuate. There is a risk that.

  In particular, in the piezoelectric actuator 32 using so-called unimorph deformation as in the present embodiment, fluctuations in the ejection characteristics of ink from the nozzles 15 when the deformation of the piezoelectric layers 41 and 42 and the diaphragm 40 are inhibited. Will be big.

  However, in this embodiment, since the raised portion 51a is formed in the portion of the flexible layer 51 that faces the conductive bump 46, the distance between the piezoelectric layer 42 and the flexible layer 51 is increased by the amount of the raised portion 51a. growing. Therefore, even if the flexible layer 51 is bent toward the piezoelectric layer 42, the flexible layer 51 can be prevented from coming into contact with the piezoelectric layer 42.

  Furthermore, the concave portion 51b is formed in the flexible layer 51, and the flexible layer 51 is deformed so as to fill the gap of the concave portion 51b. Therefore, the flexible layer 51 is easily raised, and the height of the raised portion 51a is increased. The distance between the piezoelectric layer 42 and the flexible layer 51 is large.

  In the present embodiment, since the conductive bump 46 is formed on the surface of the connection terminal 45a, when the COF 50 is pressed toward the piezoelectric layer 42, before the raised portion 51a is formed on the flexible layer 51. It is possible to prevent the flexible layer 51 from being in contact with the piezoelectric layer 42 other than the portion that becomes the raised portion 51 a (in the process of bonding the flexible layer 51 to the piezoelectric layer 42). In the case of the present embodiment, since the height of the raised portion 51a of the flexible layer 51 is controlled by the amount of the raised portion 51a, the type of the flexible layer 51, the type of the heat shrink hardening material, and the shrinkage temperature Is determined by appropriately selecting the conditions.

  Further, since the raised portion 51a is formed by raising a portion of the flexible layer 51 that faces the land 52 to the piezoelectric layer 42 side as the heat shrinkable hardening material 56 shrinks, the raised portion 51a is flexible. The flat portion adjacent to the raised portion 51a on the lower surface of the layer 51 is smoothly connected.

  Accordingly, it is possible to prevent the land 52 extending from the raised portion 51a to the flat portion adjacent to the raised portion 51a from being cracked or torn, thereby causing a crack or torn between the land 52 and the wiring 53. It can be prevented from occurring.

  Further, the land 52 extends from the raised portion 51 a to a flat portion adjacent to the raised portion 51 a, and a relatively large land 52 and a wiring 53 thinner than the land 52 are connected to the flat portion on the lower surface of the flexible layer 51. Therefore, as compared with the case where the land 52 and the wiring 53 are connected on the raised portion 51 a, it is possible to more reliably prevent the occurrence of a crack or tear between the land 52 and the wiring 53. Can do.

  As described above, according to the present embodiment, when the COF 50 is heated while being pressed against the piezoelectric layer 42 by the heater H, the heat-shrinkable hardening material 56 contracts, and accordingly, the land 52 of the flexible layer 51. In this state, the conductive bump 46 penetrates the adhesive layer 55 and comes into contact with the land 52 and is pushed out by the conductive bump 46. The adhesive layer 55 flows through the portion surrounding the conductive bump 46 and reaches the upper surface of the piezoelectric layer 42. Then, the adhesive layer 55 heated in this state is cured, whereby the land 52 and the conductive bump 46 are electrically connected, and the COF 50 and the piezoelectric layer 42 are bonded.

  Therefore, the distance between the piezoelectric layer 42 and the flexible layer 51 is increased by the amount of the raised portion 51a formed, and even if the flexible layer 51 is bent toward the piezoelectric layer 42, the flexible layer 51 contacts the piezoelectric layer 42. Can be prevented.

  Furthermore, the concave portion 51b is formed in the flexible layer 51, and the flexible layer 51 is deformed so as to fill the gap of the concave portion 51b. Therefore, the flexible layer 51 is easily raised, and the height of the raised portion 51a is increased. The distance between the piezoelectric layer 42 and the flexible layer 51 is large.

  In the present embodiment, since the conductive bump 46 is formed on the surface of the connection terminal 45a, when the COF 50 is pressed toward the piezoelectric layer 42, before the raised portion 51a is formed on the flexible layer 51. It is possible to prevent the portion other than the portion that becomes the raised portion 51 a of the flexible layer 51 from coming into contact with the piezoelectric layer 42.

  Further, since the raised portion 51a is formed by raising a portion of the flexible layer 51 that faces the land 52 to the piezoelectric layer 42 side as the heat shrinkable hardening material 56 shrinks, the raised portion 51a is flexible. The flat portion adjacent to the raised portion 51a on the lower surface of the layer 51 is smoothly connected.

  Accordingly, it is possible to prevent the land 52 extending from the raised portion 51 a to the flat portion adjacent to the raised portion 51 a from being cracked or torn, whereby the crack or torn between the land 52 and the wiring 53 is prevented. It can be prevented from occurring.

  Further, the land 52 extends from the raised portion 51 a to a flat portion adjacent to the raised portion 51 a, and a relatively large land 52 and a wiring 53 thinner than the land 52 are connected to the flat portion on the lower surface of the flexible layer 51. Therefore, as compared with the case where the land 52 and the wiring 53 are connected on the raised portion 51 a, it is possible to more reliably prevent the occurrence of a crack or tear between the land 52 and the wiring 53. Can do.

  Next, modified examples in which various changes are made to the present embodiment will be described. However, components having the same configuration as in the present embodiment are denoted by the same reference numerals, and description thereof is omitted as appropriate.

  In one modified example, as shown in FIG. 8B, the land 52 is sandwiched between the lower surface of the flexible layer 51 in a plan view before the heat shrink hardening material 56 is bonded (before the heat shrink hardening material bonding step). Thus, a pair of concave portions 51c (second concave portions) are formed (second concave portion forming step) (Modification 1). However, in this case, unlike the above embodiment, the concave portion 51c is formed on the lower surface of the flexible layer 51, and the wiring 53 cannot be formed on the left and right sides of the land 52 in FIG. The wiring 53 is connected to the land 52 on the front side or the back side of the land 52. The concave portion 51c has a continuous or discontinuous annular shape in plan view surrounding the periphery of the land 52, and has a V shape in sectional view. The recess 51c may be formed at the same time as the formation of the recess 51b (first recess formation step), or before the recess 51b is formed or after the recess 51b is formed. Also good.

  In this case, as shown in FIG. 8E, heating is performed while pressing the COF 50 toward the piezoelectric layer 42 by the heater H (bump formation process, bonding process), as in the above-described embodiment. As the heat shrink hardening material 56 contracts, the portion of the flexible layer 51 that faces the land 52 contracts toward the piezoelectric layer 42 side. At this time, the flexible layer 51 has a gap between the recess 51c in addition to the recess 51b. Therefore, the flexible layer 51 is further easily deformed, the height of the raised portion 51a is further increased, and the distance between the piezoelectric layer 42 and the flexible layer 51 is further increased.

  In the first modification, the step of forming the conductive bumps 46 shown in FIG. 8A, the step of bonding the heat-shrinkable hardening material 56 shown in FIG. 8C (heat-shrinking hardening material bonding step), and The step of forming the adhesive layer 55 (adhesive layer forming step) shown in FIG. 4D is the same as that of the above-described embodiment, and thus detailed description thereof is omitted here.

  In another modification, as shown in FIG. 9B, before the heat shrink hardening material 56 is bonded (before the heat shrink hardening material bonding step), the heat shrink hardening material 56 on the upper surface of the flexible layer 51 is After forming the recess 51d (third recess) having the same shape and the same height over the entire area to be bonded (third recess formation step), the recess 51b is formed on the bottom surface of the recess 51d. Then, the heat shrinkage hardening material 56 is bonded to the bottom surface of the recess 51d (heat shrinkage hardening material bonding step) (Modification 2).

  In the above-described embodiment, the heat shrinkable curing material 56 is bonded to the upper surface of the flexible layer 51 in which the recess 51d is not formed. Therefore, the upper surface of the flexible layer 51 has a portion where the heat shrinkable curing material 56 is bonded. In the case of the second modification, a concave portion 51d having the same height as the heat-shrinkage hardening material 56 is formed on the upper surface of the flexible layer 51, and the concave portion 51d is projected. As shown in FIG. 9D, the upper surface of the flexible layer 51 is flattened before the pressure heating by the heater H, and thereafter, as shown in FIG. As shown in the figure, a portion facing the land 52 of the flexible layer 51 by heating the COF 50 against the piezoelectric layer 42 by the heater H (heating portion forming step, bonding step). Even when allowed to bulge in the piezoelectric layer 42 side, the upper surface of the flexible layer 51 is flat. Therefore, after that, when another member is disposed on the upper surface of the COF 50, the heat shrinkable hardening material 56 does not get in the way, and the COF 50 becomes versatile and easy to use.

  In the above-described embodiment, the concave portion 51b is formed on the upper surface of the flexible layer 51. In the first modification, the concave portion 51b is formed on the upper surface of the flexible layer 51 and the concave portion 51c is formed on the lower surface. In the second modification, the recess 51b and the recess 51d are formed on the upper surface of the flexible layer 51. However, the present invention is not limited to this, and only one of the recesses 51b to 51d is formed in the flexible layer 51. Any two of the recesses 51b to 51d may be formed, or all of the recesses 51b to 51d may be formed.

  Moreover, in the above-mentioned embodiment and the modifications 1 and 2, although the recessed parts 51b-51d were formed in the flexible layer 51, it is not restricted to this. In another modification, as shown in FIG. 10 (b), a heat-shrinkable hardening material is provided at a portion facing the land 52 on the upper surface of the flexible layer 51 in which the recesses 51b to 51d (see FIGS. 7 to 9) are not formed. 56 is bonded (thermal shrinkage hardening material bonding step) (Modification 3).

  Also in this case, as shown in FIG. 10D, when the COF 50 is heated by the heater H while being pressed toward the piezoelectric layer 42 (bump formation process, bonding process), the heat shrinkable hardening material 56 contracts. As a result, the portion of the flexible layer 51 that faces the land 52 rises toward the piezoelectric layer 42 side.

  In Modification 3, the step of forming the conductive bump 46 shown in FIG. 10A (bump forming step) and the step of forming the adhesive layer 55 shown in FIG. 10C (adhesive) Since the layer forming step is the same as that of the above-described embodiment, the detailed description thereof is omitted here.

  In the present embodiment, the heat shrinkage hardening material 56 is contracted by heating the COF 50 against the piezoelectric layer 42 by the heater H, so that the portion of the flexible layer 51 that faces the land 52 is disposed in the piezoelectric layer. The conductive bump 46 and the land 52 are electrically connected and the COF 50 and the piezoelectric layer 42 are bonded at the same time when the bumps 42 are raised to the side 42, that is, the raised portion forming process and the bonding process according to the present invention are performed. I went at the same time, but not limited to this.

  In another modification, as in the above-described embodiment, as shown in FIG. 11 (c), the heat shrinkable curing material 56 is bonded to the upper surface of the flexible layer 51 (heat shrinkable curing material bonding step) and is not shown. By heating and shrinking the heat shrink hardening material 56 with a heater or the like, a portion facing the land 52 of the flexible layer 51 is raised downward to form a raised portion 51a (a raised portion forming step). Then, as shown in FIG. 11 (d), an adhesive layer 55 is formed on the lower surface of the flexible layer 51 where the raised portions 51 a are formed, and then the COF 50 is pressed against the piezoelectric layer 42 by the heater H. While heating, the land 52 and the conductive bump 46 are bonded, and the COF 50 and the piezoelectric layer 42 are bonded (bonding step) (Modification 4).

  Even in this case, the distance between the piezoelectric layer 42 and the flexible layer 51 is increased by the amount of the raised portion 51a, and the flexible layer 51 is bent toward the piezoelectric layer 42 due to the difference in linear expansion coefficient between the piezoelectric layer 42 and the piezoelectric layer 42. However, contact with the piezoelectric layer 42 can be prevented.

  In Modification 4, the step of forming the conductive bumps 46 shown in FIG. 11A (bump formation step) and the step of forming the recesses 51b shown in FIG. 10B (first recess formation step). ) Is the same as that of the above-described embodiment, and detailed description thereof is omitted here.

  In the above-described embodiment, the conductive bump 46 is formed on the upper surface of the connection terminal 45a. However, the conductive bump 46 may not be formed. In this case, the land 52 formed on the raised portion 51a contacts the surface of the connection terminal 45a, whereby the land 52 and the connection terminal 45a are electrically connected. Furthermore, even in this case, if the height of the raised portion 51a is sufficient, the interval between the piezoelectric layer 42 and the flexible layer 51 becomes large, and therefore, due to the difference in the linear expansion coefficient between the piezoelectric layer 42 and the flexible layer 51. It is possible to prevent the flexible layer 51 from coming into contact with the piezoelectric layer 42 when the flexible layer 51 is bent toward the piezoelectric layer 42 side.

  In the above-described embodiment, the COF 50 and the piezoelectric layer 42 are bonded via the adhesive layer 55, but the present invention is not limited to this.

  In another modification, as shown in FIG. 12A, the conductive bump 46 (see FIG. 7) is not formed on the surface of the connection terminal 45a, as shown in FIGS. 12B and 12C. As in the above-described embodiment, the recess 51b is formed on the upper surface of the flexible layer 51 (first recess forming step), and then the heat shrink hardening material 56 is bonded to the upper surface of the flexible layer 51 (heat shrink hardening material bonding). Process). Next, as shown in FIG. 12 (d), a solder resist layer 71 is formed on the lower surface of the flexible layer 51. Subsequently, as shown in FIG. 12 (e), the solder resist layer 71 faces the land 52. The portion is removed by etching or the like to form the through hole 71a, and the bumps of the solder 72 are formed on the surface of the land 52 exposed from the through hole 71a.

  Then, as shown in FIG. 12 (f), the COF 50 is pressed toward the piezoelectric layer 42 by the heater H (bump formation process, bonding process). Then, as the heat shrinkable hardening material 56 is heated and contracted, a portion of the flexible layer 51 facing the land 52 is raised to the piezoelectric layer 42 side to form a raised portion 51a. 72 melts and flows onto the connection terminal 45 a, whereby the connection terminal 45 a and the land 52 are electrically connected via the solder 72, and the COF 50 and the piezoelectric layer 42 are joined by the solder 72. (Modification 5).

  Even in this case, since the gap between the piezoelectric layer 42 and the flexible layer 51 is increased by the amount of the raised portion 51a, even if the flexible layer 51 is bent toward the piezoelectric layer 42, the flexible layer 51 is not deformed. Can be prevented from touching.

  In the modified example 5, the solder resist layer 71 and the solder 72 are formed on the lower surface of the flexible layer 51 after the concave portion 51b is formed and the heat shrinkable hardening material 56 is adhered. However, the solder resist layer 71 and the solder 72 are formed. After that, the concave portion 51b may be formed and the heat shrink hardening material 56 may be bonded.

  In the present embodiment, the land 52 extends from the surface of the raised portion 51a to the flat portion of the lower surface of the flexible layer 51 adjacent to the raised portion 51a. However, the present invention is not limited to this, as shown in FIG. The land 52 may be formed only on the raised portion 51a, and the land 52 and the wiring 53 may be connected on the raised portion 51a (Modification 6).

  Even in this case, the raised portion 51a and the flat portion adjacent to the raised portion 51a are smoothly connected, and the land 52 and the wiring 53 are connected on this smooth curved surface. It is possible to prevent cracks and tears from occurring between them.

  In the above description, the raised portion 51a is formed by raising the portion facing the land 52 of the flexible layer 51 as the heat shrinkable hardening material 56 shrinks. By forming the raised portion 51a by a method different from that described above, the portion where the raised portion 51a is formed on the lower surface of the flexible layer 51 and the portion adjacent to the raised portion 51a may be smoothly connected.

  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, the example in which the present invention is applied to the piezoelectric actuator unit for applying pressure to the ink in the pressure chamber 10 in the inkjet head 3 has been described. However, the piezoelectric actuator unit used in apparatuses other than the inkjet head. The present invention can also be applied to.

  In the above description, the present invention is applied to the COF 50 for applying a driving potential to the piezoelectric actuator 32. However, the present invention can also be applied to a flexible wiring member used in devices other than the piezoelectric actuator 32. .

1 is a schematic configuration diagram of a printer according to an embodiment of the present invention. It is a 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. FIG. 8 is a diagram corresponding to FIG. FIG. 8 is a diagram corresponding to FIG. FIG. 10 is a diagram corresponding to FIG. FIG. 10 is a diagram corresponding to FIG. FIG. 10 is a diagram corresponding to FIG. FIG. 10 is a diagram corresponding to FIG.

Explanation of symbols

32 Piezoelectric actuator 33 Piezoelectric actuator unit 40 Diaphragm 41, 42 Piezoelectric layer 45 Upper electrode 45a Connection terminal 46 Conductive bump 50 COF
51 Flexible layer 51a Raised portions 51b to 51d Recessed portion 52 Land 53 Wiring 55 Adhesive layer 56 Heat shrinkable hardening material 72 Solder

Claims (19)

An insulating flexible layer;
Wiring formed on one surface of the flexible layer;
It is formed on one surface of the flexible layer, and is a method for producing a flexible wiring member having a connection terminal connected to the wiring,
A heat-shrinkage-hardening material bonding step of bonding a heat-shrinkage-hardening material that shrinks and hardens when heated to a portion facing the portion where the connection terminal is formed on the surface of the flexible layer opposite to the one surface; ,
A raised portion that forms a raised portion raised on the one surface side in a portion where the connection terminal of the flexible layer is formed by heating and shrink-hardening the heat-shrinkable hardening material bonded to the flexible layer. A method for producing a flexible wiring member, comprising: a forming step. A first recess that forms a first recess in a part of the portion of the flexible layer to which the heat shrink hardening material is to be bonded before the heat shrink hardening material adhering step. Further comprising a forming step,
2. The flexible wiring according to claim 1, wherein in the heat shrink hardening material bonding step, the heat shrink hardening material is bonded so that a space is formed between the first recess and the heat shrink hardening material. Manufacturing method of member.   Prior to the raised portion forming step, a second recessed portion forming step of forming a pair of second recessed portions so as to sandwich a portion where the connection terminal is formed on the one surface of the flexible layer is further provided. The manufacturing method of the flexible wiring member according to claim 1 or 2 characterized by things. Before the heat shrink hardening material adhering step, the thickness of the heat shrink hardening material is substantially the same as the thickness of the heat shrink hardening material on the surface of the flexible layer opposite to the one surface. A third recess forming step of forming a third recess having a depth;
4. The method for manufacturing a flexible wiring member according to claim 1, wherein, in the heat shrink hardening material bonding step, the plurality of heat shrink hardening materials are bonded to a bottom surface of the third recess.   The flexible wiring according to any one of claims 1 to 4, wherein the connection terminal extends to the outside of the heat-shrinkable and hardened material when viewed from a direction orthogonal to the one surface of the flexible layer. Manufacturing method of member. A flexible layer;
Wiring formed on one surface of the flexible layer;
It is formed on the one surface of the flexible layer, and includes a connection terminal connected to the wiring,
In the portion where the connection terminal of the flexible layer is formed, a raised portion that is raised on the one surface side is formed,
The flexible wiring member, wherein the one surface of the flexible layer has a smooth connection between a portion where the raised portion is formed and a flat portion adjacent to the raised portion. The heat-shrinkable curing material that is contracted and hardened by heating, further bonded to a portion facing the connection terminal on the surface opposite to the one surface of the flexible layer,
The flexible wiring member according to claim 6, wherein the raised portion is formed by raising the flexible layer by shrinkage hardening of the heat shrinkable hardening material.   The flexible wiring member according to claim 7, wherein the connection terminal extends to the outside of the heat-shrinkage-hardening material when viewed from a direction orthogonal to the one surface of the flexible layer. A piezoelectric actuator having a piezoelectric layer having an active part and an electrode provided on the piezoelectric layer for generating an electric field in the active part;
An insulating flexible layer disposed so as to face the piezoelectric layer, a wiring layer formed on a surface of the flexible layer facing the piezoelectric layer, connected to the electrode, and the flexible layer A flexible wiring member formed on a surface facing the piezoelectric layer and having a first connection terminal connected to the wiring;
A second connection terminal connected to the plurality of electrodes is formed on a surface of the piezoelectric layer facing the flexible layer,
A method of manufacturing a piezoelectric actuator unit in which the wiring and the electrode are connected by connecting the first connection terminal and the second connection terminal,
Heat shrinkage hardening material adhesion for bonding a heat shrinkage hardening material that shrinks and hardens when heated to a portion of the surface of the flexible layer opposite to the piezoelectric layer facing the portion where the first connection terminal is formed. Process,
A raised portion that forms a raised portion raised on the side facing the piezoelectric layer in the portion of the flexible layer where the first connection terminal is formed by heating and shrinking and curing the heat-shrinkable curing material. Forming process;
A method for manufacturing a piezoelectric actuator unit, comprising: a joining step of electrically connecting the first connection terminal and the second connection terminal and joining the flexible wiring member and the piezoelectric layer.   By heating the flexible wiring member before the bulging portion is pressed from the side opposite to the piezoelectric layer toward the piezoelectric layer, the bulging portion forming step and the joining step are simultaneously performed. The method for manufacturing a piezoelectric actuator unit according to claim 9.   11. The piezoelectric actuator according to claim 10, further comprising a bump forming step of forming a bump on the first connection terminal or the second connection terminal before the protruding portion forming step and the joining step. Unit manufacturing method. Before the joining step, further comprising an adhesive layer forming step of forming a thermosetting adhesive layer on at least a portion where the connection terminal is formed on the surface of the flexible layer facing the piezoelectric layer,
In the bonding step, the flexible layer is heated while pressing from the side opposite to the piezoelectric layer toward the piezoelectric layer, so that the adhesive layer penetrates the bump, and the bump and the first connection terminal The method for manufacturing a piezoelectric actuator unit according to claim 11, wherein the piezoelectric layer and the flexible layer are bonded together by an adhesive layer pushed out by the bump. A first recess that forms a first recess in a part of the portion of the flexible layer to which the heat shrink hardening material is to be bonded before the heat shrink hardening material bonding step. Further comprising a forming step,
The heat shrink hardening material is bonded so that a space is formed between the first recess and the heat shrink hardening material in the heat shrink hardening material bonding step. A method for manufacturing the piezoelectric actuator unit according to claim 1.   Before the raised portion forming step, a second recessed portion forming step of forming a pair of second recessed portions so as to sandwich a portion where the connection terminal is formed on a surface of the flexible layer facing the piezoelectric layer. The method for manufacturing an electric actuator unit according to claim 9, further comprising: Prior to the heat shrinkage hardening material adhering step, the thickness of the heat shrinkage hardening material is almost the same as the thickness of the heat shrinkage hardening material on the surface of the flexible layer opposite to the piezoelectric layer where the heat shrinkage hardening material is bonded. A third recess forming step of forming a third recess having a depth;
The method of manufacturing an electric actuator unit according to any one of claims 9 to 14, wherein, in the heat shrink hardening material bonding step, the plurality of heat shrink hardening materials are bonded to a bottom surface of the third recess.   The connection terminal, as viewed from a direction orthogonal to the stacking direction of the piezoelectric layer and the flexible layer, extends to the outside of the heat shrink hardening material. The manufacturing method of the electric actuator unit of description.   The piezoelectric actuator unit according to any one of claims 9 to 16, wherein the piezoelectric actuator further includes a diaphragm bonded to a surface of the piezoelectric layer opposite to the flexible layer. Production method. A piezoelectric actuator having a piezoelectric layer having an active part and an electrode provided on the piezoelectric layer for generating an electric field in the active part;
An insulating flexible layer disposed so as to face the piezoelectric layer, a wiring layer formed on a surface of the flexible layer facing the piezoelectric layer, connected to the electrode, and the flexible layer A flexible wiring member formed on a surface facing the piezoelectric layer and having a first connection terminal connected to the wiring;
A second connection terminal that is connected to the electrode and connected to the first connection terminal is formed on a surface of the piezoelectric layer facing the flexible layer,
In the portion of the flexible layer where the first connection terminal is formed, a raised portion that is raised on the side facing the piezoelectric layer is formed,
The piezoelectric actuator unit characterized in that the one surface of the flexible layer has a smooth connection between a portion where the raised portion is formed and a flat portion adjacent to the raised portion. A plurality of heat-shrink hardeners that are shrink-hardened by heating, bonded to a portion of the flexible layer opposite to the connection terminal on the surface opposite to the piezoelectric layer;
19. The piezoelectric actuator unit according to claim 18, wherein the raised portion is formed by raising the flexible layer by shrinkage hardening of the heat shrink hardening material.

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