JP4985623B2 - Wiring member connection method, wiring member manufacturing method, and wiring member - Google Patents

Description

  The present invention relates to a wiring member connection method, a wiring member manufacturing method, and a wiring member.

  Patent Document 1 describes a method for manufacturing a recording head that ejects ink from nozzles by applying pressure to ink in a pressure chamber by driving a piezoelectric actuator. When manufacturing this recording head, bumps are formed on the surface of the land of the individual electrode or common electrode arranged on the upper surface of the uppermost piezoelectric sheet, and the flexible wiring in which terminal portions and wiring are formed By forming an uncured synthetic resin layer on the surface of the member (FPC) facing the piezoelectric sheet and pressing the FPC against the piezoelectric sheet by applying heat, the bumps on the piezoelectric sheet side penetrate the synthetic resin layer. In this state, the synthetic resin layer is cured by heat while being in contact with the terminal portion on the FPC side, and the piezoelectric sheet and the FPC are joined.

Japanese Patent Laying-Open No. 2005-305847 (FIG. 10)

  However, in the recording head manufacturing method described in Patent Document 1, the synthetic resin layer formed on the surface facing the FPC piezoelectric sheet covers the wiring and protects the wiring, and is applied to an area other than the terminal portion. Since the FPC is pressed toward the piezoelectric sheet in this state, there is a possibility that the uncured synthetic resin material applied to the region other than the terminal portion may adhere to the piezoelectric sheet to be connected. For example, if an uncured synthetic resin material adheres to the piezoelectric sheet and is cured, deformation of the piezoelectric sheet may be hindered. In particular, since FPC has wiring arranged on a base material layer having a high thermal expansion property, when it is heated and pressed, it tends to hang down in a state where the base material is expanded, and is easily attached to the piezoelectric sheet and hinders deformation.

  Therefore, an object of the present invention is to connect a wiring member that prevents the synthetic resin material applied so as to cover the wiring formed in the base material layer from contacting and adhering to other members in an uncured state, It is providing the manufacturing method of a wiring member, and a wiring member.

  The wiring member connection method of the present invention includes an insulating base material layer, a wiring formed on one surface of the base material layer, and a first connection terminal connected to the wiring. The second connection terminal connected to the first connection terminal is a connection method of a wiring member that is connected to a base material formed on an opposing surface facing the one surface, wherein the one surface of the base material layer includes the A first application step of applying an uncured synthetic resin material so as to cover at least the wiring except for the first connection terminals, and a first curing step of curing the synthetic resin material applied in the first application step A second application step of applying an uncured synthetic resin material so as to cover either one of the first connection terminal and the second connection terminal; and a synthetic resin material applied in the second application step The one connection terminal connected to the other And a second curing step of curing the synthetic resin material applied in the second application step, and a contact step of bringing the first connection terminal and the second connection terminal into contact with each other. It is equipped with.

  According to the method for connecting wiring members of the present invention, the uncured synthetic resin material applied so as to cover at least the wiring is already cured at the time of contact between the first connection terminal and the second connection terminal in the contact step. Therefore, the synthetic resin material applied so as to cover the wiring is in contact with and adheres to other members other than the peripheral region of the first connection terminal connected to the second connection terminal in an uncured state in the contact process. Can be prevented.

  Moreover, it is preferable to further provide the recessed part formation process which forms a recessed part in the said one surface of the said base material layer so that the outer periphery of the said 1st connection terminal may be surrounded before the said 1st application | coating process. In general, except for the surface of the first connection terminal, it is desirable that a synthetic resin is applied to the entire surface of the base material layer from the viewpoint of protection. Therefore, when an uncured synthetic resin material is applied to the side wall of the first connection terminal, the uncured synthetic resin material oozes on the surface of the first connection terminal until the uncured synthetic resin material is cured. It may harden on the surface of the connection terminal. Then, the surface area of the first contact terminal that can be contacted by the second connection terminal in the contact process becomes small, and if the position shift occurs at the time of contact between the first connection terminal and the second connection terminal, curing occurs in the first curing process. The second connection terminal comes into contact with the synthetic resin material, and a connection failure occurs between the first connection terminal and the second connection terminal, or even if the connection is established, the electrical resistance increases. End up. However, in anticipation of this, if the surface area of the surface of the first connection terminal facing the second connection terminal is increased, it becomes difficult to arrange the wirings at a high density. However, according to the wiring member connection method of the present invention, the concave portion is formed on the base material layer so as to surround the outer periphery of the first connection terminal, so that the uncured synthetic resin material applied in the first application step. Can be prevented from flowing into the recesses and bleeding on the surface of the first connection terminal, so that the surface area of the surface of the first connection terminal can be reduced. In this way, conduction failure can be prevented and wirings can be arranged at high density.

  In addition, in the first application step, it is preferable that an uncured synthetic resin material is applied to the entire surface of the base layer except for the first connection terminal. According to this, the synthetic resin material is applied to the side wall of the first connection terminal, and migration that occurs between the first connection terminal and the adjacent wiring can be prevented.

  Moreover, it is preferable to further include a bump forming step of forming a conductive bump on the other connection terminal. According to this, since the conductive bump is formed on the other connection terminal, in the contact process, the other connection terminal is passed through the synthetic resin layer applied in the second coating process via the conductive bump. It is easy to make contact with the connection terminals, and poor conduction can be prevented. Moreover, a space | interval can be opened between a wiring member and a base material only by the height of a conductive bump, and the contact with a base material and a wiring member can be prevented.

  Furthermore, it is preferable that conductive bumps are formed on the second connection terminals in the bump forming step, and an uncured synthetic resin material is applied so as to cover the first connection terminals in the second application step. According to this, compared with the 2nd connection terminal in which the bump was formed, the 1st connection terminal in which the bump is not formed is easier to apply the synthetic resin material.

  According to the wiring member connection method of the present invention, a wiring member having an insulating base material layer, a wiring formed on one surface of the base material layer, and a first connection terminal connected to the wiring is piezoelectric. A wiring member connected to a piezoelectric actuator having a layer and a second connection terminal formed on a surface facing the wiring member and connected to the first connection terminal, the method comprising: A first application step of applying an uncured synthetic resin material so as to cover at least the wiring, excluding the first connection terminal, and the synthetic resin material applied in the first application step on the one surface A first curing step for curing; a second coating step for coating an uncured synthetic resin material so as to cover either one of the first connection terminal and the second connection terminal; and the second coating step. In synthetic resin material A contact step in which the other connection terminal is relatively pressed against the one connection terminal and the first connection terminal and the second connection terminal are brought into contact with each other, and the composition applied in the second application step A second curing step for curing the resin material.

  According to the method for connecting wiring members of the present invention, the uncured synthetic resin material applied so as to cover at least the wiring is already cured at the time of contact between the first connection terminal and the second connection terminal in the contact step. Therefore, the synthetic resin material applied so as to cover the wiring is in contact with and adheres to other members other than the peripheral region of the first connection terminal connected to the second connection terminal in an uncured state in the contact process. Can be prevented. For example, it is possible to prevent uncured synthetic resin from adhering to the piezoelectric layer and inhibiting the deformation of the piezoelectric layer.

  According to the wiring member connection method of the present invention, the piezoelectric actuator unit includes a flow path unit in which a liquid flow path including a pressure chamber is formed, and a piezoelectric actuator unit that applies pressure to the liquid in the pressure chamber. A wiring member having an insulating base layer, a wiring formed on one surface of the base material layer, and a first connection terminal connected to the wiring, a piezoelectric layer, and the wiring member And a piezoelectric actuator having a second connection terminal connected to the first connection terminal, the wiring member connecting method in a liquid ejection head, wherein A first application step of applying an uncured synthetic resin material on the surface so as to cover at least the wiring except for the first connection terminal, and a synthetic resin material applied in the first application step A first curing step of curing the second coating step, a second coating step of coating an uncured synthetic resin material so as to cover one of the first connection terminal and the second connection terminal, and the second coating Contacting the first connection terminal with the second connection terminal by relatively pressing the other connection terminal against the one connection terminal to which the synthetic resin material is applied in the step; A second curing step of curing the synthetic resin material applied in the coating step.

  According to the method for connecting wiring members of the present invention, the uncured synthetic resin material applied so as to cover at least the wiring is already cured at the time of contact between the first connection terminal and the second connection terminal in the contact step. Therefore, the synthetic resin material applied so as to cover the wiring is in contact with and adheres to other members other than the peripheral region of the first connection terminal connected to the second connection terminal in an uncured state in the contact process. Can be prevented. For example, it is possible to prevent fluctuations in liquid ejection characteristics in the liquid ejection head due to adhesion of uncured synthetic resin to the piezoelectric layer and deformation of the piezoelectric layer.

  The wiring member of the present invention includes an insulating base material layer, a wiring formed on one surface of the base material layer, and a first connection terminal formed on one surface of the base material layer and connected to the wiring. And a concave portion formed on the one surface of the base material layer so as to surround the outer periphery of the first connection terminal, and a synthesis covering the entire surface excluding the first connection terminal on the one surface of the base material layer. A surface height of the synthetic resin layer covering the concave portion is lower than a surface height of the first connection terminal.

According to the wiring member of the present invention, an uncured synthetic resin material is applied to the first connection terminal formed on the base material layer, and the second connection terminal formed on the base material is pressed against the first connection terminal. Another synthetic resin material that has already been applied so as to cover the wiring formed on the base material layer is already cured, and in contact with other members such as the base material in an uncured state. Adhesion can be prevented. Further, since the surface height of the synthetic resin layer covering the concave portion of the base material layer is lower than the surface height of the first connection terminal, the uncured synthetic resin material is blocked by the side wall of the first connection terminal. It is possible to prevent the first connection terminal from bleeding.
At this time, the surface height of the synthetic resin layer covering the recess is preferably lower than the surface height of the first connection terminal and the surface height of the synthetic resin layer covering the periphery outside the recess. As a result, the uncured synthetic resin material, which is attached later, pushed out by the second connection terminal flows into the concave portion lower than the surface height of the first connection terminal, and does not easily protrude outside the concave portion.

  It is possible to prevent the synthetic resin material applied so as to cover the wiring formed on the base material layer from contacting and adhering to other members in an uncured state.

  Hereinafter, preferred embodiments of the present invention will be described. FIG. 1 is a schematic configuration diagram of a printer according to the present embodiment. This printer 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 main body. In the following description, the direction in which ink is ejected from the nozzles 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).

  In addition, a sheet conveying roller 4 and a platen 6 are arranged opposite to each other on the downstream side of the carriage 2 in the sheet feeding direction, and the recording sheet P is sandwiched between the two, and the recording sheet P is forward (paper feeding direction) in FIG. ). The inkjet head 3 is disposed on the lower surface of the carriage 2, and a plurality of nozzles 15 (see FIG. 5) are exposed and opened on the lower surface of the carriage 2. The printer 1 ejects ink from the inkjet head 3 that reciprocates in the scanning direction together with the carriage 2 onto the recording paper P that is conveyed in the paper feeding direction by the paper conveying roller 4, thereby conveying the recording paper P that is conveyed. To print.

  Next, the inkjet head 3 will be described. FIG. 2 is a perspective view of the inkjet head. FIG. 3 is a plan view of the inkjet head. 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. FIG. 7 is a partial cross-sectional view of the bump and its vicinity.

  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 7, 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 including the nozzle 15 and the pressure chamber 10 are formed. A piezoelectric actuator unit 33 that applies pressure to the ink in the pressure chamber 10 to eject ink from 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 to 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 is formed from the outlet of the manifold flow path 11 to the pressure chamber 10 via the flow path 12 and from the pressure chamber 10 to the nozzles 15 via the flow paths 13 and 14. 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, extends in a plan view to a position where it overlaps with the longitudinal direction of the pressure chambers 10 and communicates with the ink supply port 9.

  Next, the piezoelectric actuator 32 will be described. 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, and a conductive bump 46. 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 disposed between the diaphragm 40 and the piezoelectric layer 41, and corresponds to each pressure chamber group 7 as shown in FIG. The pressure chamber rows 8 extend in the paper feeding direction, and face the plurality of pressure chambers 10 constituting the two pressure chamber rows 8 so as to overlap in a 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 connecting portions 44b, as shown in FIG. 44c. 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 feed direction, and among the two pressure chamber rows 8 constituting each pressure chamber group 7, a plurality of pressure chamber rows 8 arranged on the right side of FIG. The ends on the right side of FIG. 4C of the plurality of facing portions 44a corresponding to the pressure chamber 10 are connected to each other. 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 chamber rows 8 arranged on the left side in FIG. The left ends of FIG. 4C of the plurality of facing portions 44a corresponding to the pressure chamber 10 are connected to each other. 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 correspond to the plurality of pressure chambers 10 on the upper surface of the piezoelectric layer 42 (surface facing the COF 50). The upper electrodes are arranged so as to face the entire area, are arranged in the paper feed direction, form an upper electrode row group, and constitute rows of two upper electrodes 45 included in one upper electrode row group The 45s are displaced from each other with respect to 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. A part of the upper electrode 45 at the end opposite to the nozzle 15 in the scanning direction extends to a portion that does not oppose the pressure chamber 10 in the scanning direction, and this portion is a land 52 (first connection terminal: see FIG. 5) of the COF 50. ) And is a connection terminal 45a (second connection terminal) made of an Ag—Pd-based material. The connection terminal 45a is made of a conductive material such as a metal (in this embodiment, a resin containing resin, and a conductive material containing Ag, such as NH-070A (T) manufactured by Nihon Solder Co., Ltd.), A bump 46 is provided.

  As will be described later, the upper electrode 45 is connected to a wiring connected to the land 52 by contact between the conductive bump 46 and the land 52 on the COF 50, and the driver IC 54 mounted on the COF 50 via this wiring. The potential is switched between the ground potential and the above-described predetermined potential (for example, 20 V). 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 connected to the land (not shown) on the COF 50 through the conductive bumps, similarly to the upper electrode 45.

  Further, 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 will be described. The COF 50 that applies a potential to the piezoelectric actuator 32 includes a flexible layer 51 (base material layer), a plurality of lands 52 (first connection terminals), a plurality of wirings 53, 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 insulation and flexibility, and has a larger linear expansion coefficient than the piezoelectric material forming the piezoelectric layers 41 and 42. The flexible layer 51 is disposed on the piezoelectric actuator 32 with its lower surface facing the piezoelectric layer 42. A recess 51 a is formed between the land 52 on the lower surface of the flexible layer 51 and the wiring 53 adjacent to the land 52 so as to surround the outer periphery of the land 52.

  The plurality of lands 52 are made of a conductive material such as copper, and are printed on the lower surface of the flexible layer 51. The plurality of wirings 53 are made of a conductive material such as copper, printed on the lower surface of the flexible layer 51, and connected to the plurality of lands 52 on the lower surface of the flexible layer 51.

  In addition, the flexible layer 51 and the piezoelectric layer 42 are joined by a thermosetting synthetic resin layer 55 so as to cover the surfaces of the conductive bumps 46 and the lands 52 at portions facing the conductive bumps 46 and the lands 52. ing. Further, the synthetic resin layer 55 covers the entire lower surface of the flexible layer 51, and also covers the conductive bumps 46 and the wirings 53 other than the portions facing the lands 52. The portion of the synthetic resin layer 55 excluding the portion facing the conductive bump 46 and the land 52 is not in contact with the piezoelectric layer 42 and is not involved in the bonding between the flexible layer 51 and the piezoelectric layer 42.

  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 a wiring 53 for outputting a drive signal to the electrodes 43 to 45 or receiving a drive 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 a predetermined potential and then returned to the ground potential. When the potential of the upper electrode 45 is switched to a 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 part of the layers 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 expansion of the piezoelectric layer 42 causes the expansion of the piezoelectric layers 41 and 42. Partially absorbed by 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. And the lower electrode 43 are stretched to the state before contraction, and 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 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. 8A and 8B are process diagrams showing the manufacturing process of the inkjet head, FIG. 8A is a bump forming process, FIG. 8B is a wiring and land forming process, and FIG. 8C is a recess forming process. FIG. 8D is a first application process, FIG. 8E is a first curing process, FIG. 8F is a second application process, and FIG. 8G is a contact process. FIG. 8 (h) shows the second curing step. In the manufacture of the inkjet head 3, first, a plurality of plates 21 to 24 are stacked and joined to form the flow path unit 31, and the diaphragm 40 is joined to the flow path unit 31, and the piezoelectric layer 41. , 42 and electrodes 43 to 45 are formed to constitute a laminate. In the following, a method for connecting the COF 50 to the laminate will be described.

  First, as shown in FIG. 8A, the upper portion formed on the surface of the piezoelectric layer 42 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 connection terminal 45a of the electrode 45 by printing or the like (bump forming step). The conductive bump 46 is formed of a conductive paste such as Ag containing resin and has elasticity.

  Also, as shown in FIG. 8B, the land 52 and the wiring 53 are formed by printing or the like as a process different from the process shown in FIG. 8A (wiring and land forming process). Thereafter, as shown in FIG. 8C, the region where the land 52 is to be formed and the wiring 53 adjacent to the land 52 are formed on the lower surface of the flexible layer 51 (the surface facing the piezoelectric layer 42 in a later step). A recess 51a is formed by laser processing, etching, sand blasting or the like so as to surround the land 52 between the region to be formed (recess forming step).

Next, as shown in FIG. 8D, the entire bottom surface is covered with a thermosetting material such as a solder resist so as to cover the region where the land 53 is formed except for the region where the land 52 of the flexible layer 51 is formed. The synthetic resin material 61 is printed (first application process). In the first application step, the synthetic resin material 61 is printed with a squeegee (not shown) through the mask 100 in which the opening 101 is formed except for the region facing the land 52. The synthetic resin material 61 is maintained in an uncured (semi-cured) state that does not sag from the flexible layer 51 by appropriately adjusting various conditions such as temperature and viscosity. At this time, since the opening 101 of the mask 100 is opened in a region excluding the region facing the land 52 including the concave portion 51 a surrounding the land 52, the thickness of the synthetic resin material 61 printed on the flexible layer 51. Has the same thickness including the recess 51a so as to surround the land 52, and since the recess 51a is formed on the flexible layer 51, the synthetic resin material 61 applied along the recess 51a. Forms the recess 52a, and the surface height of the synthetic resin material 61 in the recess 51a is lower than the surface height of the synthetic resin layer and the land 52 covering the periphery of the outer side of the recess 51a .

  Next, as shown in FIG. 8E, the flexible layer 51 is heated from the upper side (side on which the synthetic resin material 61 is not printed) by a heater (not shown) to cure the synthetic resin material 61 (first curing). Process). At this time, the synthetic resin material 61 is applied in close contact with the side wall of the land 52, and migration that occurs between the land 52 and the adjacent wiring 53 can be reliably prevented. Migration means that when the wiring is densified and the distance between the land 52 and the wiring 53 is reduced, the material forming the land 52 or the wiring 53 is a metal due to the potential difference between the two when a drive signal is transmitted through the wiring 53. This is a phenomenon that elutes as ions, moves between adjacent lands 52 and wirings 53 on the surface of the flexible layer 51 by an electric field, precipitates as metal, and makes both conductive. And as shown in FIG.8 (f), uncured thermosetting synthetic resin materials, such as a soldering resist, through the mask in which opening was formed only in the area | region facing the land 52 so that the land 52 might be covered 62 is applied (second application step).

  Subsequently, as shown in FIG. 8G, the COF 50 is directed from the opposite side to the piezoelectric layer 42 toward the piezoelectric layer 42 in a state where the land 52 and the conductive bump 46 are aligned to face each other in plan view. Pressing while heating with a heater (not shown) (heating / contact process). Then, the conductive bump 46 penetrates through the uncured synthetic resin material 62 and comes into contact with the land 52 to be electrically connected, and the synthetic resin material 62 extruded by the penetration of the conductive bump 46 is The portion surrounding the conductive bump 46 flows according to gravity and reaches the upper surface of the connection terminal 45a of the piezoelectric layer 42, and flows into the recess 52a around the land 51 of the COF 50 and does not flow into the wiring 53 side than the recess 52a.

  The uncured synthetic resin material 62 temporarily decreases in viscosity until it is cured by heating, and more easily flows on the surface of the conductive bump 46. In particular, when the uncured synthetic resin material 62 uses the same solder resist as the synthetic resin material 61 previously covered with the wiring 53 and cured, the uncured synthetic resin material 62 is The hardened synthetic resin material 61 can easily flow into the wiring 53 side, and the uncured synthetic resin material 62 that has flowed into the wiring 53 side may come into contact with the piezoelectric layer. However, since the recessed portion 52a is formed, the extruded uncured synthetic resin material 62 can remain in the recessed portion 52a, so that it can be prevented from flowing out to the wiring 53 side.

  Further, as shown in FIG. 8F, when the uncured synthetic resin material 62 is applied so as to cover the lands 62, the synthetic resin material 62 surrounds the periphery when contacting the conductive bumps. When the resin material 62 is small, the mechanical connection strength is small and the film is easily peeled off. Therefore, the amount of the synthetic resin material 62 applied is as shown in FIG. It is preferable that uncured synthetic resin covering the surface of the bump reaches the surface of the connection terminal 45a. (For example, the synthetic resin layer is about 15 to 20 μm and the bump height is 35 μm). For this reason, as shown in FIG. 8F, it is conceivable that the uncured synthetic resin material 62 flows out of the land 62 in the coating stage covering the land 62. Since the recess 52a is formed on the surface, it is possible to prevent the uncured synthetic resin material 62 from flowing out at the application stage.

  The conductive bump 46 includes a resin and is formed of a conductive material including Ag. Therefore, the conductive bump 46 has elasticity, and the tip of the conductive bump 46 is crushed to increase a contact area. In addition, the reliability of the electrical connection between the conductive bump 46 and the land 52 can be improved, and the distance between the COF 50 and the piezoelectric layer can be increased. Further, since the conductive bumps 46 are formed, the synthetic resin material 62 can be easily brought into contact with the lands 52, and poor conduction can be prevented.

  Since the heating is performed by the heater, the synthetic resin material 62 between the COF 50 and the piezoelectric layer 42 is cured as shown in FIG. 8H (second curing step). Thereby, the land 52 and the conductive bump 46 are mechanically connected in addition to the electrical connection, and the COF 50 and the piezoelectric layer 42 are joined. In this way, the synthetic resin materials 61 and 62 are cured, so that the synthetic resin layer 55 is formed covering the surfaces of the conductive bumps 46 and the lands 52 and covering the entire lower surface of the flexible layer 51. In this way, the synthetic resin layer 55 covering the entire lower surface of the flexible layer 51 obtained by first curing the synthetic resin material 61 and then curing the synthetic resin material 62 is formed on the conductive bumps 46 and the lands 52. In addition to covering the surface, the wiring region can be formed.

  In this embodiment, in order to protect the wiring 53, the synthetic resin material 61 applied so as to cover the wiring 53 is already cured at the time of contact between the land 52 and the conductive bump 46 in the contact process. If the contact process is performed in a state where the synthetic resin material 61 is uncured and the flexible layer 51 comes into contact with the piezoelectric layer 42, the synthetic resin material 61 adheres to the surface of the piezoelectric layer 42 and remains. There is a fear. In particular, when the flexible layer 51 has a high linear expansion coefficient, such as the COF 50, the flexible layer 51 is likely to expand and hang down in the pressing / curing process using the heater. In this state, when the synthetic resin material 61 is cured and the piezoelectric actuator 32 is driven as described above, the deformation of the piezoelectric layers 41 and 42 and the diaphragm 40 is hindered, and the ejection characteristics of the ink from the nozzles 15 are reduced. May fluctuate. In particular, in the piezoelectric actuator 32 using so-called unimorph deformation as in the present embodiment, the variation in the ejection characteristics of the ink from the nozzle 15 when the deformation of the piezoelectric layers 41 and 42 and the diaphragm 40 is hindered. It will be big. Therefore, in the present embodiment, the synthetic resin material 61 applied so as to cover the wiring 53 is cured before the contact step, so that the synthetic resin material 61 is uncured in the contact step and in the piezoelectric layer 42. It can prevent that it contacts and adheres to other members.

  Further, if the recess 51a is not formed so as to surround the land 52, for example, when the uncured synthetic resin material 61 is applied to the side wall of the land 52 in order to prevent migration, the uncured synthetic resin material 61 Since the thixotropy is small, the synthetic resin material 61 may ooze on the surface of the land 52 before reaching the first curing step, and may be cured on the surface of the land 52 in the first curing step. As a result, the surface area of the land 52 that can be contacted by the conductive bump 46 in the contact process becomes small, and when the land 52 and the conductive bump 46 are in contact with each other, a displacement occurs on the synthetic resin material 61. Will be in contact with each other, resulting in poor connection between the land 52 and the conductive bump 46, or even if electrical connection is established, the electrical resistance will increase. Therefore, it is conceivable to increase the surface area of the surface of the land 52 facing the conductive bump 46, but it is difficult to arrange the wirings 53 at a high density. In the present embodiment, since the recess 51a is formed so as to surround the outer periphery of the land 52, the uncured synthetic resin material 61 applied in the first application step flows along the recess 51a to form the recess 52a. The surface height of the recess 52 a is lower than the surface height of the land 52. Therefore, it is possible to prevent the uncured synthetic resin material 61 from being blocked by the side walls of the lands 52 and bleeding to the surface of the lands 52. In this way, the conduction failure can be prevented, the surface area of the land 52 can be reduced, and the COF in which the wirings 53 are arranged at a high density can be manufactured. When the COF coated with the synthetic resin layer 61 is manufactured, bleeding can be prevented on the surface of the land 52, so that the yield can be improved.

  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 the present embodiment, the synthetic resin material 62 is applied so as to cover only the land 52 in the second application step. However, the synthetic resin material 62 may be applied so as to cover the land 52 and the recess 51a. . As a result, as shown in FIG. 9, when the COF 50 and the piezoelectric layer 42 are brought into contact with each other in the contact step, the synthetic resin material 62 around the contact region becomes a thick layer, and the conductive bumps 46 and The synthetic resin material 62 surrounding the land 52 spreads to the recess 51a, and the bonding strength between the COF 50 and the piezoelectric layer 42 can be improved. Therefore, it is possible to prevent the COF 50 from being peeled off from the piezoelectric layer 42 and disconnecting the electrical connection between the land 52 and the conductive bump 46. Note that, by increasing the depth of the recess 51a formed in the flexible layer 51, the synthetic resin material 62 that can be received in the recess 51a is increased, and the bonding strength between the COF 50 and the piezoelectric layer 42 can be further improved. it can. The recesses are not necessarily formed so as to surround the entire periphery of the land 52, but may be formed between the land and the adjacent wiring region, and are not continuous, but intermittently around the land 52. You may form in several places.

  In the above-described embodiment, the conductive bump 46 is formed on the upper surface of the connection terminal 45a. However, the conductive bump may be formed on the land 52 on the COF 50 side. In this case, from the viewpoint of easy application of the synthetic resin material 62 in the second application step, the synthetic resin material 62 is preferably applied to the connection terminal 45a on the flexible layer 51 side where the conductive bumps are not formed. Further, the conductive bumps 46 are not necessarily used.

  In the above-described embodiment, the recess forming process is performed after the wiring and land forming process. However, the recess forming process may be performed before the wiring and land forming process. Further, in the above-described embodiment, the COF 50 and the piezoelectric layer 42 are bonded via the insulating synthetic resin material 62 having no conductivity. However, the COF 50 and the piezoelectric layer 42 may be bonded by a synthetic resin having conductivity.

  Further, in the above-described embodiment, the synthetic resin material 61 is applied up to the side wall of the land 52 in the first application step, but the synthetic resin material 67 is applied so as to cover at least the wiring 53 as shown in FIG. It only has to be done. Thereby, it is possible to prevent the synthetic resin material 61 from bleeding on the surface of the land 52. At this time, since the synthetic resin material 62 pushed out by the conductive bumps 46 flows between the synthetic resin material 61 and the land 52 in the contact step, the concave portion 51a need not be formed. However, it is preferable to apply the synthetic resin material 61 to the side wall of the land 52 from the viewpoint of migration prevention after forming the concave portion 51 a so that the synthetic resin material 61 does not spread on the surface of the land 52.

  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 wiring member used in a device other than the piezoelectric actuator 32.

1 is a schematic configuration diagram of a printer according to an embodiment. It is a perspective view of an inkjet head. It is a top view of an inkjet head. (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.4 (a). It is the VI-VI sectional view taken on the line of Fig.4 (a). It is a fragmentary sectional view of a bump and its neighborhood. FIG. 8A is a process diagram illustrating a manufacturing process of an inkjet head, FIG. 8A is a bump formation process, FIG. 8B is a recess formation process, and FIG. 8C is a wiring and land formation process; FIG. 8 (d) is a first application process, FIG. 8 (e) is a first curing process, FIG. 8 (f) is a second application process, and FIG. 8 (g) is a contact process. FIG. 8H shows the second curing step. FIG. 6 is a view corresponding to FIG. 5 in a modified example. It is sectional drawing of the flexible layer in a modification.

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 Recess 52 Land 53 Wiring 55 Synthetic resin layer 61, 62 Synthetic resin material

Claims (9)

A wiring member having an insulating base material layer, a wiring formed on one surface of the base material layer, and a first connection terminal connected to the wiring, is connected to the first connection terminal. A connection method of a wiring member for connecting to a base material formed on a facing surface where the connection terminal faces the one surface,
In the one surface of the base material layer, a first application step of applying an uncured synthetic resin material so as to cover at least the wiring except for the first connection terminal;
A first curing step of curing the synthetic resin material applied in the first application step;
A second application step of applying an uncured synthetic resin material so as to cover either one of the first connection terminal and the second connection terminal;
A contact step in which the other connection terminal is relatively pressed against the one connection terminal to which the synthetic resin material is applied in the second application step to bring the first connection terminal and the second connection terminal into contact with each other. ,
And a second curing step of curing the synthetic resin material applied in the second application step.   2. The method according to claim 1, further comprising a recess forming step of forming a recess on the one surface of the base material layer so as to surround an outer periphery of the first connection terminal before the first application step. The connection method of the wiring member of description.   3. The wiring member according to claim 2, wherein, in the first application step, an uncured synthetic resin material is applied to the entire surface of the base layer except for the first connection terminal. Connection method.   The wiring member connection method according to claim 1, further comprising a bump formation step of forming a conductive bump on the other connection terminal. In the bump forming step, a conductive bump is formed on the second connection terminal,
5. The wiring member connection method according to claim 4, wherein in the second application step, an uncured synthetic resin material is applied so as to cover the first connection terminals. 6. A wiring member having an insulating base material layer, a wiring formed on one surface of the base material layer and a first connection terminal connected to the wiring, a piezoelectric layer, and the wiring member facing A wiring member connection method for connecting to a piezoelectric actuator having a second connection terminal formed on a surface and connected to the first connection terminal,
In the one surface of the base material layer, a first application step of applying an uncured synthetic resin material so as to cover at least the wiring except for the first connection terminal;
A first curing step of curing the synthetic resin material applied in the first application step;
A second application step of applying an uncured synthetic resin material so as to cover either one of the first connection terminal and the second connection terminal;
A contact step in which the other connection terminal is relatively pressed against the one connection terminal to which the synthetic resin material is applied in the second application step to bring the first connection terminal and the second connection terminal into contact with each other. ,
And a second curing step of curing the synthetic resin material applied in the second application step. A flow path unit in which a liquid flow path including a pressure chamber is formed;
A piezoelectric actuator unit that applies pressure to the liquid in the pressure chamber;
The piezoelectric actuator unit is
A wiring member having an insulating base layer, a wiring formed on one surface of the base material layer, and a first connection terminal connected to the wiring;
A wiring member connection method in a liquid discharge head, comprising: a piezoelectric layer; and a piezoelectric actuator formed on a surface facing the wiring member and having a second connection terminal connected to the first connection terminal. And
In the one surface of the base material layer, a first application step of applying an uncured synthetic resin material so as to cover at least the wiring except for the first connection terminal;
A first curing step of curing the synthetic resin material applied in the first application step;
A second application step of applying an uncured synthetic resin material so as to cover either one of the first connection terminal and the second connection terminal;
A contact step in which the other connection terminal is relatively pressed against the one connection terminal to which the synthetic resin material is applied in the second application step to bring the first connection terminal and the second connection terminal into contact with each other. ,
And a second curing step of curing the synthetic resin material applied in the second application step. An insulating substrate layer;
Wiring formed on one surface of the base material layer;
A first connection terminal formed on one surface of the base material layer and connected to the wiring;
A recess formed on the one surface of the base material layer so as to surround an outer periphery of the first connection terminal;
A synthetic resin layer covering the entire surface excluding the first connection terminal on the one surface of the base material layer;
The wiring member according to claim 1, wherein a surface height of the synthetic resin layer covering the concave portion is lower than a surface height of the first connection terminal. The surface height of the synthetic resin layer covering the concave portion is lower than the surface height of the first connection terminal and the surface height of the synthetic resin layer covering the outer periphery of the concave portion. The wiring member according to 8.

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