JP2008141078A - Connection structure of wiring board and connection inspecting method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connection structure in which the displacement of connection between wirings of wiring boards can be detected accurately and inexpensively with a small number of components by enabling a terminal originally provided in each wiring board to work as a displacement detecting terminal. <P>SOLUTION: In the connection structure of a wiring board, a specific connection terminal 12Aa of the wiring board has a shape different from that of each of the other connection terminals 12Ba, 12Ca, 12Da and includes an inspection portion 12Aaa in which a distance with the connection terminal 12Ba adjacent thereto becomes partially smaller. For the connection status between the connection terminal of the wiring board and the electrode terminal of another wiring board, the displacement of the connection status of the both can be accurately inspected on the basis of the presence of conduction status of the electrode terminal portion 11Ba contacting the inspecting portion 12Aaa. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wiring board connection structure and a connection inspection method thereof.

  In electronic devices and the like, a wiring board is used to supply a driving signal and a driving voltage, and there are cases where two wiring boards are connected and used. In such a case, for example, as shown in FIG. 7A, the electrode terminal portions A1, A2, A3 of the first wiring board and the connection terminals B1, B2, B3 of the second wiring board are connected. It is necessary to connect securely by matching the arrangement pitch. At that time, for example, the electrode terminal portions A1 to A3 and the connection terminals B1 to B3 may be misaligned in the arrangement direction. When the misalignment is large, the electrode terminal portions A1 to A3 and the connection terminals are short-circuited. It may wake up. Therefore, it is conceivable to perform a function inspection by providing a terminal for checking a positional deviation when connecting the wiring boards. As such a device, a check terminal that is not related to driving of an electronic device is separately provided, and a device using the fact that the check terminals are shifted when a positional shift occurs is known (for example, Patent Document 1). , 2, 3).

In this way, it is possible to electrically detect a positional shift at a time based on whether or not continuity is possible and a difference in resistance value by conducting a continuity check of the check terminal.
Japanese Patent Laid-Open No. 05-121854 (paragraphs 0021, 0026 and FIG. 1) Japanese Patent Laying-Open No. 2003-158354 (paragraphs 0026 and 0030 and FIG. 3) JP 2001-183692 A (paragraphs 0035 to 0037 and FIGS. 1 and 2)

  However, in the thing of the said patent documents 1-3, in addition to the wiring and terminal which play an electrical role, since the wiring and the terminal are specially provided for the check, in addition to the originally necessary wiring and terminal Further, it is necessary to provide extra wiring and terminals, which causes an increase in cost and is not preferable in terms of space saving.

  Furthermore, with the recent increase in the density of wiring, for example, as shown in FIG. 7B, the amount of positional deviation between the electrode terminal portions A1 to A3 and the connection terminals B1 to B3 is within a tolerance range. Although they are connected in a state where they are not short-circuited, the distance between them may be narrowed. In such a case, the wiring connection inspection is passed in the inspection at the time of manufacture. However, when time elapses during use, migration or the like occurs, and an electrical short circuit occurs while driving. There is a fear. Such misalignment that can lead to a potential short circuit is inaccurate to identify in visual inspection, has poor productivity, and is short-circuited even with conventional functional inspection. There was a problem that it could not be detected.

  Therefore, the present invention can detect a positional shift that causes such a potential short circuit, and also has a function of inspecting the positional shift in the electrode terminal portion and the connection terminal that are inherently provided in the wiring board (that is, the dual purpose). It is an object of the present invention to provide a wiring board connection structure and a connection inspection method thereof that can be inspected inexpensively with a component configuration with little positional deviation without adding a terminal for inspection.

  The invention of claim 1 is directed to a wiring board connection structure in which each connection terminal of the second wiring board is connected to each electrode terminal portion of the first wiring board so as to overlap each other. In the first wiring board, a plurality of wirings are formed, and each wiring has an electrode terminal portion at one end thereof, while the second wiring board is formed with a plurality of wirings. It is assumed that one end of the wiring is configured to have a connection terminal that is formed at the same pitch as the electrode terminal portion and is connected correspondingly. According to the first aspect of the present invention, a specific electrode terminal portion of the plurality of electrode terminal portions or a specific connection terminal of the plurality of connection terminals has a shape different from other electrode terminal portions or connection terminals. The specific electrode terminal portion or the specific connection terminal includes a portion in which a distance from the electrode terminal portion or the connection terminal adjacent to the specific electrode terminal portion or the specific connection terminal is partially reduced.

  In this way, the specific electrode terminal portion or the specific connection terminal has a portion in which the distance from the adjacent electrode terminal portion or the connection terminal is partially reduced. Then, it is possible to inspect a positional deviation that induces a potential short circuit. Furthermore, the specific electrode terminal part or the specific connection terminal has a shape different from that of the other electrode terminal part or the connection terminal, and the specific electrode terminal part or the specific connection terminal is the electrode terminal part adjacent to it. Alternatively, since the gap between the connection terminals is partially reduced, when a positional shift occurs, a specific electrode terminal portion or a specific connection terminal and an electrode terminal portion or a connection terminal adjacent to the specific electrode terminal portion However, since the short circuit occurs earlier than other adjacent electrode terminal portions or connection terminals, it is possible to detect the positional deviation amount that causes a potential short circuit more accurately and reliably. In addition, since the specific electrode terminal portion or the specific connection terminal has a shape different from that of the other electrode terminal portion or the connection terminal and is used for the inspection of misalignment, a terminal for inspection is specially provided. Therefore, the positional deviation can be inspected at a low cost with a small configuration, and the space can be saved.

  According to a second aspect of the present invention, in the wiring board connection structure according to the first aspect, the specific electrode terminal portion or the specific connection terminal is on the adjacent electrode terminal portion or the adjacent connection terminal side in a plan view. It can also be set as the structure which has a part to protrude.

  In this way, in addition to the effect of claim 1, the specific electrode terminal portion or the specific connection terminal has a protruding portion, so that an interval between the electrode terminal portion or the connection terminal adjacent thereto is increased. Since the portion that is partially reduced is configured, the configuration is simple.

  The wiring board connection structure according to claim 2, wherein the adjacent electrode terminal portion or connection terminal has a recessed portion corresponding to the protruding portion in plan view. It can also be.

  In this way, in addition to the effect of claim 2, by having a recessed portion corresponding to the protruding portion, a portion where the interval is partially reduced is formed. Inspection of positional deviation is ensured by the combination of the portion to be recessed and the recessed portion.

  5. The wiring board connection structure according to claim 1, wherein the specific electrode terminal portion or the specific connection terminal has a notch portion in plan view, and the adjacent electrode terminal portion. Alternatively, the connection terminal has a key-shaped protrusion corresponding to the notch, while the connection terminal or electrode terminal corresponding to the specific electrode terminal or the specific connection terminal is the key-shaped protrusion. It can also be set as the structure which has a key-shaped protrusion which engages at intervals.

  In this way, in addition to the effect of the first aspect, since the specific electrode terminal portion or the specific connection terminal and the corresponding connection terminal or electrode terminal portion corresponding to the key shape are engaged with each other, the misalignment is prevented. Inspection can be performed with high accuracy.

  According to a fifth aspect of the present invention, in the wiring board connection structure according to any one of the first to fourth aspects, the wirings of the first and second wiring boards are respectively formed when the inkjet head is manufactured or driven. The inkjet head is provided with individual electrodes and piezoelectric layers corresponding to a plurality of pressure chambers, while a common internal electrode is provided for the plurality of pressure chambers with the piezoelectric layer interposed therebetween. The drive signal is supplied to the individual electrodes and the internal electrodes through the wirings of the wiring boards, and the wiring connected to the specific electrode terminal portion is connected to the internal electrode in the manufacturing process. It is used when a predetermined voltage is applied between them to polarize the piezoelectric layer, and the wiring connected to the adjacent electrode terminal portion is connected to the internal electrode. Kill. According to a sixth aspect of the present invention, in the wiring board connection structure according to any one of the first to fourth aspects, the wirings of the first and second wiring boards are each driven or manufactured when the inkjet head is manufactured. The inkjet head is provided with individual electrodes and piezoelectric layers corresponding to a plurality of pressure chambers, while an internal electrode common to the plurality of pressure chambers is sandwiched between the piezoelectric layers. The drive signal is supplied to the individual electrode and the internal electrode through the wirings of the two wiring boards, and the wiring connected to the specific connection terminal is connected to the internal electrode The wiring connected to the adjacent connection terminal is used when a predetermined voltage is applied between the internal electrode and the piezoelectric layer in the manufacturing process to polarize the piezoelectric layer. It can be.

  In these cases, in addition to the effect of any one of claims 1 to 4, there is no need for a space for separately providing inspection wiring and terminals, so that space can be saved and the wiring density and size can be reduced. Can also respond. In addition, the cost is low. Furthermore, since the wiring of the electrode terminal portion or connection terminal of the ink jet head is one that has a ground potential during normal use or one that is used to polarize the piezoelectric layer, it is time-lapse during normal use. Even if a short circuit occurs due to a change, the short circuit does not affect the operation.

  The wiring board connection structure according to any one of claims 1 to 6, wherein the specific electrode terminal portion or the specific connection terminal includes the plurality of electrode terminal portions or the plurality of connection terminals. It is good also as a structure arrange | positioned near the end of the direction of arrangement.

  If it does in this way, in addition to the effect in any one of Claims 1-6, since it has arrange | positioned near the end of the direction where an electrode terminal part or a connection terminal is arranged, it is in other electrode terminal parts and a connection terminal. The effect is small.

  According to the invention of claim 8, when each connection terminal of the second wiring board is overlapped and connected to each of the electrode terminal portions of the first wiring board, their connection state is changed. The first wiring board has a configuration in which a plurality of wirings are formed, and each wiring has an electrode terminal portion at one end thereof. It is assumed that the wiring board 2 has a configuration in which a plurality of wirings are formed and one end of each wiring is formed at the same pitch as the electrode terminal portion and has connection terminals to be connected correspondingly. The invention according to claim 8 has a shape in which a specific electrode terminal portion of the plurality of electrode terminal portions or a specific connection terminal of the plurality of connection terminals is different from other electrode terminal portions or connection terminals. The specific electrode terminal portion or the specific connection terminal includes an inspection portion in which a distance from the electrode terminal portion or the connection terminal adjacent to the specific electrode terminal portion or the connection terminal is partially reduced, and the plurality of electrodes of the first wiring board When connecting each of the plurality of connection terminals of the second wiring board to each of the terminal portions, the specific electrode terminal portion or the connection terminal via the connection terminal or the electrode terminal portion in contact with the inspection portion The inspection is performed based on the presence or absence of a conduction state with the adjacent electrode terminal portion or connection terminal.

  In this way, depending on the presence or absence of a conduction state between the specific electrode terminal part or connection terminal and the adjacent electrode terminal part or connection terminal through the connection terminal or electrode terminal part in contact with the inspection portion, Misalignment that can cause a potential short circuit can be easily and reliably inspected.

  According to a ninth aspect of the present invention, in the wiring board connection inspection method according to the eighth aspect, the wirings of the first and second wiring boards are used when manufacturing or driving the inkjet head, respectively. The inkjet head is provided with individual electrodes and piezoelectric layers corresponding to the plurality of pressure chambers, while a common internal electrode is provided for the plurality of pressure chambers with the piezoelectric layer interposed therebetween, And the drive signal is supplied to the internal electrodes through the wirings of the two wiring boards, and the wiring connected to the specific electrode terminal portion has a predetermined gap between the internal electrodes in the manufacturing process. It is used when a voltage is applied to polarize the piezoelectric layer, and the wiring connected to the adjacent electrode terminal portion may be connected to the internal electrode.According to a tenth aspect of the present invention, in the wiring board connection inspection method according to the eighth aspect, the wirings of the first and second wiring boards are used when manufacturing or driving the inkjet head, respectively. The inkjet head is provided with individual electrodes and piezoelectric layers corresponding to a plurality of pressure chambers, while a common internal electrode is provided for the plurality of pressure chambers with the piezoelectric layer interposed therebetween, The drive signals are supplied to the individual electrodes and the internal electrodes through the wirings of the two wiring boards, and the wirings connected to the specific connection terminals are connected to the internal electrodes, The wiring connected to the adjacent connection terminal may be used when a predetermined voltage is applied between the internal electrodes and the piezoelectric layer is polarized in the manufacturing process.

  In these cases, in addition to the effect of the eighth aspect, the ground potential or the wiring of the electrode terminal portion or the connection terminal used only when the piezoelectric layer is polarized is used. Since it uses the thing used when polarizing a thing and a piezoelectric layer, even if it short-circuits by a time-dependent change at the time of normal use, it can test | inspect that the short circuit does not affect operation. .

  As described above, in the present invention, the specific electrode terminal portion or the specific connection terminal is provided with the inspection portion in which the distance between the electrode terminal portion or the connection terminal adjacent to the specific electrode terminal portion or the connection terminal is partially reduced. Therefore, it is possible to inspect a positional deviation that may cause a potential short circuit. In particular, a specific part of the electrode terminal part or connection terminal originally provided on the wiring board has a different shape and is used for the inspection of misalignment, so there are few parts without adding a special terminal for the inspection. It is possible to inspect the positional deviation at a low cost with the configuration.

  Hereinafter, the present invention relates to a connection structure for connecting wiring between wiring boards such as electronic devices and a connection inspection method thereof, and is applied to, for example, an inkjet head. FIG. 1 is a perspective view showing a state in which a flexible wiring board is bonded to the upper surface of an inkjet head to which the present invention is applied.

  As shown in FIG. 1, the inkjet head 1 is formed by laminating an actuator unit 3 and a flexible wiring member 4 on a flow path unit 2 in the same manner as the known one described in JP-A-2006-198903. It is composed. The ink-jet head 1 is used in an ink-jet recording apparatus for recording. Although not specifically illustrated, the ink-jet head 1 is a direction X (mainly perpendicular to the recording paper transport direction Y (sub-scanning direction). It is mounted on a carriage that reciprocates in the scanning direction.

  The flow path unit 2 of the inkjet head 1 is a laminated body in which a plurality of plate members are laminated, a plurality of arranged pressure chambers 2a, and a plurality of nozzles (not shown) communicating with the pressure chambers 2a, An ink flow path (not shown) that communicates ink from an ink supply source (not shown) to each pressure chamber 2a and nozzles is provided.

  The actuator unit 3 is a laminated body in which a plurality of piezoelectric layers 23 (for example, PZT) are laminated, and a plurality of individual electrodes (not shown) corresponding to the plurality of pressure chambers 2a and a plurality of pressure chambers 2a. A common internal electrode (not shown) is configured with the piezoelectric layers 23 interposed therebetween. The common internal electrode is connected to the ground, and by selectively applying a voltage to the individual electrode, the portion of the piezoelectric layer 23 sandwiched between the individual electrode and the internal electrode is selectively driven as a piezoelectric deformation portion. As a result, the ink is deformed, pressure is applied to the ink in the pressure chamber, the ink is selectively ejected through the plurality of nozzles, and the recording operation is performed on the recording paper (recording medium).

  Further, on the uppermost surface of the actuator unit 3, the surface individual electrode 22 and the surface internal electrode 24 are formed by screen printing with a silver-palladium conductive member. Similarly to the known configuration described in Japanese Patent No. 80709, individual electrodes in the piezoelectric layer 23 are formed through a conductive material filled in through holes (not shown) penetrating in the stacking direction of the stacked piezoelectric layers 23. And are connected to a common internal electrode.

  A flexible wiring board 4 is laminated on the upper surface of the actuator unit 3. As shown in FIG. 2, the flexible wiring board 4 is configured by connecting a first wiring board 5 and a second wiring board 6. A plurality of wirings 11A to 11D and a wiring 13 are formed on the first wiring board 5, and wirings 12A to 12D are formed on the second wiring board 6 so as to extend in the longitudinal direction (X direction) of the flexible wiring material 4, respectively. The electrode terminal portions 11Aa, 11Ba, 11Ca, 11Da (11 in a collective manner) and the connection terminals 12Aa, 12Ba, 12Ca, 12Da provided at the ends of the wirings 11A-11D, 12A-12D connected to each other The flexible wiring material 4 is configured by overlapping and connecting (12 when collectively referred to).

  In the present embodiment, the first wiring board 5 and the second wiring board 6 use, for example, a flexible printed circuit board (FPC) as the first wiring board 5 and the second wiring board 6 in the present embodiment. .

  The second wiring member 6 has a plurality of wirings 12A, 12B, 12C, 12D, etc. such as copper on one surface of a strip-like base material made of a flexible synthetic resin material (for example, polyimide resin) having electrical insulation. .. Are freely designed and wired with a photoresist or the like, and these surfaces are covered with a cover lay made of a flexible synthetic resin (for example, polyimide resin) having electrical insulation. On one end side of the second wiring member 6 on the side connected to the first wiring member 5, the connection terminals 12Aa, 12Ba, 12Ca, 12Da, etc. are connected to the wirings 12A to 12D in the width direction (Y direction), respectively. Provided at a pitch, and at the other end, another connection terminal 15 (generally referred to) corresponding to the wirings 12A to 12D is provided at an equal pitch to provide a connector for electrical connection with the main body side. Connected. Since the second wiring member 6 is a flexible printed circuit board, the wiring widths of the wirings 12A to 12D can be designed freely, as shown in FIG. 2, than the width on the other end side equal to a predetermined width of a general connector. Also, the width on one end side can be shortened. In this way, even when connected to the first wiring member 6 to be described later, the wiring board 4 can also be miniaturized and high-density wiring can be made corresponding to the miniaturization of the flow path unit 2 and the actuator unit 3. It is.

  The first wiring board 5 has individual electrode bumps 13 a formed on the back surface on one end side in the longitudinal direction (X direction) corresponding to the individual surface electrodes 22 and the inner surface electrodes 24 of the actuator unit 3. The electrode terminal portions 11Aa, 11Ba, 11Ca, 11Da,... Are arranged side by side on the other end side (side on which the driver IC 7 is provided), and the second wiring material is provided. 6 corresponding to the same pitch as the electrode terminal portions 12. A driver IC 7 that is a drive circuit extending in the width direction (Y direction) is mounted on the first wiring board 5, and a drive signal such as print data from the control device on the main body side, a drive voltage, or the like is applied to the actuator. This is transmitted to the unit 3 to selectively drive the actuator unit 3.

  Further, the first wiring board 5 includes a plurality of input-side wirings 11B (VSS2), 11C (VDD2), 11D for inputting the driving signal, driving voltage, and the like to the driver IC 7, and the actuator unit 3 from the driver IC 7. A plurality of output-side wirings 13 that are output to the front surface and surface electrode bumps 11AA are formed. Further, a wiring 11 </ b> A (COM) that is electrically connected to the internal electrode is formed to extend in the longitudinal direction (X direction) of the wiring substrate 4. The output wiring 13 extends from the driver IC 7 in the X direction and is electrically connected to the individual electrodes by being connected to the individual electrode bumps 13a.

  The electrode terminal portions 11Aa, 11Ba, and 11Ca are arranged substantially symmetrically in this order near both ends in the direction (Y direction) in which the plurality of electrode terminal portions 11 are arranged. In the central portion in the direction (Y direction) in which the plurality of electrode terminal portions 11 are arranged, a plurality of other electrode terminal portions 11Da,. In other words, two terminal portions 11Aa, 11Ba, and 11Ca are provided approximately symmetrically in this order on both end edges in the width direction (Y direction) of the wiring board, and a plurality of terminal portions 11Da are arranged inside. Has been. The electrode terminal portions 11Aa to 11Da correspond to the connection terminals 12Aa to 12Da formed at the same pitch as described above, are formed at the same pitch, and overlap each other to be electrically connected to each other. A wiring board 4 is provided. The first wiring member 5 has the same configuration as the second wiring member 6, and has copper or the like on one side of a strip-like base material made of a flexible synthetic resin material (for example, polyimide resin) having electrical insulation. A plurality of wirings 11A to 11D, 13 are formed of a photoresist or the like, and these surfaces are covered with a cover lay made of an electrically insulating and flexible synthetic resin (for example, polyimide resin). Yes.

  Here, the connection between the first wiring member 5 and the second wiring member 6 will be described. The electrode terminal 11 at one end of the first wiring member 5 is exposed on the lower surface (the side opposite to the mounting side of the driver IC 7), and the second wiring member 6 is connected to the first wiring member 5 at one end. By removing the electrical insulating coating on the surface, the copper wire is exposed and used as the connection terminal 12. Since the electrode terminals 11 and the connection terminals 12 are arranged symmetrically at the same pitch, the exposed terminals are overlapped in a one-to-one correspondence and formed on either surface. Are connected by heating. For example, the second wiring member 6 is fixed, a conductive brazing material is placed on the connection surface side of the connection terminal 12, the electrode terminals 11 of the first wiring member 5 are overlapped on the upper side, and the electrode terminal 11 side is Heat with a heater. Further, an electrical insulating tape (not shown) is attached so as to cover the side where the terminal of the connecting portion is exposed. By connecting in this way, the wirings 11A to 11D and the wirings 12A to 12D are also connected one-to-one. As shown in FIG. 3, the width of the electrode terminal 11 is wider than the width of the connection terminal 12 if it is within a tolerance at the time of connection between the two so that a potential short circuit does not occur. This is because it can be corrected and functions as a relief pattern of the conductive brazing material. The connection terminal 15 on the side connected to the connector of the second wiring member 6 exposes the wiring by removing the electrical insulation coating on one side of the wiring along the surface direction of the second wiring board 6. Connected to the connector.

  Here, the details of the wirings 11A to 11D of the first wiring board 5 will be described.

  At the outermost end edges in the width direction (Y direction) of the first wiring board 5, the wirings 11 </ b> A extending from the electrode terminals 11 </ b> Aa and 11 </ b> Aa extend along the side edges in the longitudinal direction (X direction) of the first wiring board 5. Are parallel to each other, and are electrically connected to the internal electrodes via the surface electrode bumps 11AA, and are at ground potential.

  Each wiring 11B of the electrode terminal portions 11Ba and 11Ba adjacent to each other inside the electrode terminal portions 11Aa and 11Aa extends to the vicinity of the driver IC 7 inside each wiring 11A, and both electrode terminal portions 11Ba and 11Ba are mounted at the mounting position of the driver IC 7. Are connected to each other. A wiring portion near the loop is connected to an input side connection terminal of the driver IC 7 (not shown) under the driver IC 7. As will be described later, the wiring 11B is a wiring VSS2 used when a predetermined voltage is applied between the internal electrode and the ground potential in the manufacturing process to polarize the piezoelectric layer 23. The wiring VSS2 is grounded during normal driving of the ink jet printer apparatus.

  Each wiring 11C of the electrode terminal portions 11Ca and 11Ca adjacent to the inner side of the electrode terminal portion 11Ba also extends to the vicinity of the driver IC 7 inside the wirings 11A and 11B, and both the electrode terminal portions 11Ca and 11Ca are connected at the mounting position of the driver IC 7. They are connected to each other by forming a tying loop. In addition, a wiring portion near the loop is connected to an input connection terminal of the driver IC 7 (not shown) under the driver IC 7. The wiring 11C is a wiring VDD2 for supplying a driving voltage (here, 30V) to the driver IC 7.

  A plurality of wirings 11D of the plurality of electrode terminal portions 11Da... Between the electrode terminal portions 11Ca on both sides extend to the driver IC 7 and function as signal lines for supplying input signals.

  The input signal input to the electrode terminal portion 11Da is controlled in the same way as the drive control known in Japanese Patent Laid-Open No. 2002-160372 via the driver IC 7, thereby deforming the piezoelectric deformation portion (PZT in FIG. 4). Let Referring to FIG. 4, a shift register 111, a D flip-flop 112, a driver 105, and the like are configured in the driver IC 7. A plurality of shift registers 111 and D flip-flops 112 are provided corresponding to the number of nozzles, and conducting wires for supplying these driving voltages are conducting wires VDD1 and VSS1. Also, a plurality of piezoelectric deformation portions of the driver 105 and the reference C (PZT) are prepared according to the number of nozzles, and the conductive wires for supplying these drive voltages (30V in this case) are the conductive wires VDD2 and VSS2. These are the wiring 11B and the wiring 11C of the wiring board 4 that has been prepared. VSS2 is commonly connected to the common potential portion of the driver 105, and is normally grounded. Further, the conducting wire COM in which the electrodes opposite to the driver IC 5 of the piezoelectric deformation portion PZT are commonly connected is the wiring 11A described above, and the conducting wire COM and the conducting wire VSS2 are connected by the conducting wire 65.

An input signal is serially input to the driver IC 7 and converted into a parallel signal, and also converted into a drive signal having a voltage corresponding to the drive voltage input from the wiring 11C (VDD2). Then, the drive signal is supplied from the driver IC 7 to the individual electrode through the output side wiring 13 and the terminal portion 13a, and each piezoelectric deformation portion (PZT) is driven. A driver 105 that generates a drive signal to be supplied to each piezoelectric deformation unit is provided independently for each piezoelectric deformation unit, is supplied with a drive voltage from the wiring 11C, and outputs a drive signal through each wiring 13. The common electrode is grounded through the wiring 11A (COM).
Moreover, since wiring 12A-12D is connected with wiring 11A-11D, it is wiring used for the same objective.

  Next, a connection structure between wiring substrates using a specific connection terminal 12Aa and a connection detection method thereof will be described.

  The connection terminal 12Aa of the wiring 12A (COM) of the second wiring member 6 is an electrode terminal portion of the wiring COM and also has a positional deviation detection function as the specific electrode terminal portion 12Aa. FIG. 3 shows each electrode terminal part 11 of the wirings COM, VSS2 and VDD2 and the connection part 100a to the electrode terminal part 12 as shown in FIG. For the sake of explanation, among the arrangement directions (Y direction) of the electrode terminal portions 11 and the connection terminals 12, in FIG. 2, the connection portion 100a side is defined as the Y1 direction, and the opposite side is defined as the Y2 direction.

  The specific electrode terminal portion 12Aa has a different shape from the other electrode terminal portions 12Ba, 12Ca, 12Da,... As shown in FIG. The inspection part 12Aaa which becomes smaller is provided. That is, the other electrode terminal portions 12Ba, 12Ca, 12Da,... Have a rectangular shape in plan view, but the specific electrode terminal portion 12Aa is the side of the adjacent electrode terminal portion 12Ba as the inspection portion 12Aaa in plan view. Has a small rectangular portion protruding into the surface. The amount of protrusion of the inspection portion 12Aaa is acceptable in the inspection after manufacture, but when the time elapses due to use, migration or the like occurs and there is a possibility of short-circuiting. . Since the electrode terminal part 12 is a flexible printed circuit board, it is easy to make it into a different shape.

  Thereby, for example, when the electrode terminals 11 of the first wiring board 5 are overlapped and joined to the connection terminals 12 of the second wiring board 6, among the arrangement directions (Y direction), When the first wiring board 5 is connected with a displacement in the Y1 direction, the inspection portion 12Aaa of the connection terminal 12Aa of the wiring 12A (COM) of the second wiring board 6 is connected to the wiring of the first wiring board 5 11B (VSS2), which is in contact with the electrode terminal 11Ba, that is, whether or not the wiring COM and the wiring VSS2 are in a conductive state, a potential short circuit occurs when the electrode terminal portions 11A to 11D and the connection terminals 12A to 12D are connected. It is possible to inspect whether or not the positional deviation that causes the Also, as shown in FIG. 4A, in FIG. 2, the same configuration is applied to the connection portion 100b on the opposite side (Y2 direction side) to the connection portion 100a of the wiring board 4 in the width direction (Y direction). Can be adopted. That is, if the inspection portion 12Aaa of the connection terminal 12Aa has a small rectangular portion that similarly protrudes toward the adjacent connection terminal 12Ba, and the interval with the adjacent connection terminal 12Ba is partially reduced, the connection Even when a positional shift in the Y2 direction in the arrangement direction (Y direction) occurs depending on whether the inspection portion 12Aaa of the terminal 12Aa and the electrode terminal portion 11Ba are in contact with each other, the conductive state of the wiring COM and the wiring VSS2 By detecting the presence or absence, it is possible to detect a positional shift that induces a potential short circuit in the Y2 direction.

  In the above example, the second wiring member 6 is connected to the first wiring member 5, but the wiring COM and the wiring VSS2 are in contact with each other relative to the positional deviation. Since it is only necessary to confirm the conduction state by doing so, it goes without saying that even when the second wiring member 6 is bonded to the first wiring member 5, the positional deviation can be detected.

  Further, the wiring connected to the specific connection terminal 12Aa used for the inspection is the wiring COM, and the wiring COM is connected to the internal electrode that is at the ground potential during normal use, and is adjacent to the electrode terminal portion. The wiring VSS2 connected to 11Ba is used to polarize each piezoelectric deformation portion by applying a predetermined voltage between the internal electrode and the internal electrode in the manufacturing process. Therefore, even if the connection terminal 12Aa and the electrode terminal portion 11Ba are short-circuited due to aging during normal use, the short-circuit does not affect the operation of the inkjet head 1.

  In this way, in any of the adjacent terminals of the electrode terminals 11Aa and 11Ba and the connection terminals 12Aa and 12Ba of the COM wirings (11A and 12A) and the VSS2 wirings (11B and 12B) of the wiring boards 5 and 6, respectively. If the inspection part having a different shape in which the width between the matching terminals is partially reduced is provided and conduction between the COM wiring and the VSS2 wiring has occurred, it is determined whether or not a positional shift causing a potential short circuit has occurred. Can be inspected.

  Therefore, another embodiment as shown in FIGS. 3B to 3D and FIG. 4 is possible.

  (i) As shown in FIG. 3B, the specific connection terminal 12Aa partially has a small chevron-shaped portion that protrudes toward the adjacent connection terminal 12B as the inspection portion 12Aab in plan view. A configuration is also possible. A similar configuration can be applied to the connection portion 100b side.

  (ii) Further, instead of the specific connection terminal 12Aa as shown in FIG. 3C, the specific electrode terminal 11Ba ′ of the wiring 11B (VSS2) of the first wiring board 5 is replaced with the other electrode terminals 11Aa ′ and 11Ca. , 11Da,..., And a configuration including an inspection portion 11Baa in which the distance from the adjacent connection terminal 11Aa ′ is partially reduced. That is, the specific electrode terminal 11Ba ′ (VSS2) partially has a protruding portion 11Baa protruding toward the specific electrode terminal 11Aa ′ side of the wiring 11A (COM) adjacent to the specific electrode terminal 11Ba ′ (VSS2). The interval between and is partially reduced. The electrode terminal 11Aa (COM) adjacent to the electrode terminal 11Aa (COM) may have a configuration in which the inspection portion 11Aaa that is recessed so as to mesh with the protruding inspection portion 11Baa is partially seen in plan view. Further, the connection terminals 12Aa to 12Da of the wiring 12 have a rectangular shape in plan view.

  With this configuration, when the first wiring board 5 is connected to the second wiring board 6 as in the previous connection method, the position of the first wiring board 5 is shifted in the Y1 direction. If the connection terminal 12Aa "(COM) and the inspection part 11Baa of the electrode terminal part 11Ba '(VSS2) are in contact with each other, a potential short-circuit can be prevented by inspecting the continuity between the wiring COM and the wiring VSS2. In this case, similar to the above-described embodiment, the same configuration can be applied to the connecting portion 100b, and position deviation detection in the Y2 direction can be performed. .

  In this embodiment, since each electrode terminal portion 12 of the second wiring member 6 has a rectangular shape in plan view, a so-called general-purpose flexible cable (FFC) is used for the second wiring member 6. Can do. The FFC has a configuration in which an electrically insulating film is coated on the front and back surfaces of conductive wiring such as copper, and a parallel wiring pattern (pitch width 1 mm) extends in the longitudinal direction (X direction) and extends in the width direction (Y The electrode terminal portions are also formed in parallel and at equal pitch. FFC is preferable in terms of cost because it is less expensive than a flexible printed circuit board.

(iii) Further, the specific electrode terminal portion or the specific connection terminal has a cutout portion in a plan view, and the adjacent electrode terminal portion or connection terminal protrudes in a key shape corresponding to the cutout portion. The connection terminal or the electrode terminal portion corresponding to the specific electrode terminal portion or the specific connection terminal has a key-shaped protrusion that meshes with the key-shaped protrusion with a gap. It is also possible to do. For example, as shown in FIG. 3D, the notch 11Aab is provided in the electrode terminal 11Aa ″, and the adjacent electrode terminal 11Ba ″ has a key-like protruding portion 12Ba arranged in the notch 12Aab. The connection terminal 12Aac ″ ′ partially includes a key-shaped inspection portion 11Aac that meshes with the key-shaped protruding portion 11Bab. In this case as well, by providing a similar configuration in the connection portion 100b, it is possible to detect a positional deviation in the reverse direction.

(Iv) In the embodiment described above, the wiring pitches of the first and second wiring members 5 and 6 are equal to each other, and the pitch intervals are formed at equal pitches. In addition, the connection terminals 12 are also provided at the same pitch and at equal pitch intervals. However, the connection terminals 12 are not particularly required to be equal pitches, and as long as both the electrode terminal portions 11 and the connection terminals 12 have the same pitch as each other, Even if the arrangement pitch widths of the electrode terminal portion 11 and the connection terminal 12 are not equal, the same configuration as the above-described inspection portion can be applied, and the connection inspection can be performed. In this case, for example, as shown in FIG. 4B, the length of the protruding portion of the inspection portion 12Aaa of the specific connection terminal 12Aa becomes longer according to the arrangement pitch length, but the protruding amount of this inspection portion 12Aaa is In the inspection after the manufacturing, it is considered to be acceptable, but when the time elapses due to use, migration or the like occurs and the electrical short circuit is likely to be adjusted.

(V) Also, the wiring COM and the wiring VSS2 are arranged in the center in this order near both end edges in the width direction (Y direction) of the wiring board so that the arrangement relationship with other wiring and other wiring are less affected. However, if there is no particular limitation as described above, it is possible to perform a connection inspection using the above-described embodiment even if the arrangement is not near the end in this order. It is.

  Next, the polarization process related to the bump 5C will be described.

  In the manufacturing process of the inkjet head 1, first, an actuator unit 3 in which a plurality of piezoelectric layers 23 (PZT) are stacked and fired on a flow path unit 2 in which a plurality of plates are stacked and bonded is separately prepared in advance. After bonding or bonding, the uppermost surface individual electrode 22 and surface inner electrode 24 of the actuator unit 3 and the individual electrode bump 13a and inner electrode bump 11AA of the flexible wiring board 4 are made of conductive brazing material (solder). Connect them electrically. The flexible wiring board 4 has a first wiring board 5 and a second wiring board 6 connected in advance.

  Then, each piezoelectric deformation part (piezoelectric layer 23) of the actuator unit 3 is polarized. The electrode terminal portions 11Aa and 11Ba and the wirings 11A and 11B used for this polarization are used for the inspection.

  This polarization process will be described with reference to FIG. The polarization device 101 includes a circuit 102 that generates a part of the polarization voltage, a power supply 103 that is equivalent to a power supply that performs the discharge operation for generating the remaining part of the polarization voltage, an enable signal, a reset signal, and the like. And a signal circuit 104 for generating a signal. The power supply 103 and the signal generation circuit 104 are the same as those known, for example, in Japanese Patent Laid-Open No. 2002-160372, which are provided in the printer main body for performing an ejection operation, and will not be described in detail.

  The circuits 104 and 102 and the power source 103 are connected to the terminal portions of the wirings 11A to 11D formed on the flexible wiring board 4. The circuit 102 includes a wiring COM (wiring 11A) connected to the common electrode (ground potential) below the piezoelectric layer 23 and a wiring connected to each driver 105 of the driver IC 7 connected to each individual electrode 22 above the piezoelectric layer 23. This is a circuit for applying a polarization voltage to VSS2 (wiring 11B). Therefore, the circuit 102 includes a negative power supply −VCC2, switches SW1 and SW2, and a resistor R2. A power supply 103 equivalent to the power supply for performing the above-described ejection operation is connected between the wiring VDD1 and the wiring VSS1 and between the wiring VDD2 (wiring 11C) and the wiring VSS2. In addition, in the state where the wiring COM and the wiring VSS2 are not connected by the wiring 65, the polarization of each piezoelectric deformation portion is performed.

  Next, detailed processing of this polarization will be described with reference to FIGS. When polarization is performed, the switch SW1 is set to the G side and the switch SW2 is set to the G side (ground side). In other words, the negative power source −VCC2 and the wiring COM are not connected, and in this state, the reset signal of the shift register 111 and the D flip-flop 112 is set to the H level, and all the data of the shift register 111 and the D flip-flop 112 are stored. Discharge is set to 0. When the enable signal is raised from the L level to the H level, the output of the OR gate becomes the H level, and all the drivers 105 start energizing the piezoelectric deformation portion PZT. At this time, since the switches SW1 and SW2 are still on the G side, the voltage Vpzt applied to the piezoelectric deformation portion PZT is 30 V (the voltage drop due to the resistor R2 is ignored here). Since this is the same as the voltage applied to the piezoelectric deformation portion PZT during ejection, no polarization is performed.

  Slightly from this state, the switches SW1 and SW2 are set to the N side. Then, the voltage of the power source VCC2 (here, −20V) is applied, and the voltage across the piezoelectric deformation portion PZT becomes 50V in addition to the previous 30V. This voltage starts polarization. When the polarization is completed, the enable signal is set to L level. Since the output of the D flip-flop 112 is set to L level by the reset signal, when the enable signal becomes L level, the output of the OR gate also becomes L level. As a result, the driver 105 stops energization of the piezoelectric deformation portion PZT, and only the voltage 40V from the power supply VCC2 is applied to the piezoelectric deformation portion PZT. Then, after a predetermined time has elapsed from here, the switch SW2 is returned to the G side, and the voltage Vpzt of the piezoelectric deformation portion PZT becomes zero. When polarization is completed in this way, the polarization device is removed from the flexible wiring board 4, the wiring VSS2 and the wiring COM are connected by the wiring 65, and the inkjet head 1 is attached to the printer main body.

  According to such a manufacturing method, since the polarization is performed after the flexible wiring board 4 of the inkjet head 1 is bonded, the deterioration of the polarization does not occur. In addition, the voltage used for polarization is obtained by lowering the potential of the electrode opposite to the driver IC 7 with respect to the discharge power supply voltage. Therefore, a high voltage is not applied to the driver IC 7, and therefore the driver IC 7 is polarized. It is prevented from breaking inside.

  When the polarization voltage -VDD2 is applied, the output voltage V0 of the driver IC 7 is the VDD2 voltage (30 V), so that the current flows in the direction from the driver IC 7 to the piezoelectric deformation portion PZT, and the polarization voltage -VDD2 Since the output voltage V0 of the driver IC 7 is zero (0 V) at the time of discharging, the current is directed so as to flow into the driver IC 7 from the piezoelectric deformation portion PZT.

  Therefore, since only the voltage in the range of 0 to VDD2 is applied to the output voltage V0 of the driver IC 7, the possibility that the driver IC 7 breaks down during polarization is further reduced.

  In order to describe the wiring connection structure between the wiring boards and the connection inspection method, the present invention provides a connection structure between the first wiring member 5 and the second wiring member 6 of the flexible wiring member 4 of the inkjet head and the connection inspection method thereof. Although described as an example, the present invention is not particularly limited, and the present invention can be applied when wiring boards are connected to each other in products using electric wiring such as general electronic equipment and inspection equipment. The specific electrode terminal portion or the specific connection terminal between the wiring boards has a portion where the distance from the adjacent electrode terminal portion or the connection terminal is partially reduced, and has a different shape from the other terminal portions. Therefore, when a misalignment between the wiring boards occurs, the circuit board is short-circuited earlier than other adjacent electrode terminal portions or connection terminals, and a misalignment that cannot be inspected by the conventional function inspection. Possible accuracy of the connection test is high can detect. In addition, there is no special provision of a terminal for inspection, and the space can be saved with a small configuration, and the positional deviation can be easily inspected at low cost, and the productivity is good.

It is a perspective view which shows the state by which the flexible wiring board was joined to the upper surface of the inkjet head to which this invention is applied. It is a figure which shows the wiring board by which a 1st wiring board and a 2nd wiring board are connected. (A)-(d) is explanatory drawing of a test | inspection part, respectively. (A)-(d) is explanatory drawing of a test | inspection part, respectively. It is a circuit explaining a polarization process. It is explanatory drawing of a polarization process. (A) (b) is explanatory drawing of a prior art example, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet head 5,6 Wiring board 11A, 11B, 11C, 11D Wiring 11Aa, 11Ba, 11Ca, 11Da Electrode terminal part 12A, 12B, 12C, 12D Wiring 12Aa, 12Ba, 12Ca, 12Da Connection terminal

Claims (10)

The first wiring board has a structure in which a plurality of wirings are formed and each wiring has an electrode terminal portion at one end thereof, while the second wiring board has a plurality of wirings formed at one end of the wirings. Is formed at the same pitch as the electrode terminal portion and has a connection terminal correspondingly connected thereto, and each connection of the second wiring board to each electrode terminal portion of the first wiring board. A wiring board connection structure in which terminals are connected in correspondence with each other,
A specific electrode terminal portion of the plurality of electrode terminal portions, or a specific connection terminal of the plurality of connection terminals has a shape different from other electrode terminal portions or connection terminals,
The connection structure for a wiring board, wherein the specific electrode terminal portion or the specific connection terminal includes a portion in which an interval between the specific electrode terminal portion or the specific connection terminal is partially reduced.   2. The wiring board connection structure according to claim 1, wherein the specific electrode terminal portion or the specific connection terminal has a portion protruding toward the adjacent electrode terminal portion or the adjacent connection terminal in a plan view. .   3. The wiring board connection structure according to claim 2, wherein the adjacent electrode terminal portion or connection terminal has a recessed portion corresponding to the protruding portion in plan view. The specific electrode terminal portion or the specific connection terminal has a notch portion in plan view, and the adjacent electrode terminal portion or the connection terminal has a key-shaped protrusion corresponding to the notch portion. ,
The connection terminal or the electrode terminal portion corresponding to the specific electrode terminal portion or the specific connection terminal has a key-shaped protrusion that meshes with the key-shaped protrusion with a space therebetween. The connection structure of the wiring board according to 1. The wirings of the first and second wiring boards are used when manufacturing or driving the inkjet head, respectively.
The inkjet head is provided with individual electrodes and piezoelectric layers corresponding to a plurality of pressure chambers, while a common internal electrode is provided for the plurality of pressure chambers with the piezoelectric layer interposed therebetween. The drive signal is supplied to the electrodes through the wirings of both the wiring boards,
The wiring connected to the specific electrode terminal portion is used when a predetermined voltage is applied between the internal electrode and the piezoelectric layer in the manufacturing process to polarize the piezoelectric layer,
The wiring board connection structure according to claim 1, wherein the wiring connected to the adjacent electrode terminal portion is connected to the internal electrode. The wirings of the first and second wiring boards are used when manufacturing or driving the inkjet head, respectively.
The inkjet head is provided with individual electrodes and piezoelectric layers corresponding to a plurality of pressure chambers, while a common internal electrode is provided for the plurality of pressure chambers with the piezoelectric layer interposed therebetween. The drive signal is supplied to the electrodes through the wirings of both the wiring boards,
The wiring connected to the specific connection terminal is connected to the internal electrode,
The wiring connected to the adjacent connection terminal is used when a predetermined voltage is applied between the internal electrode and the piezoelectric layer in a manufacturing process to polarize the piezoelectric layer. The connection structure of the wiring board in any one of 1-4.   The specific electrode terminal portion or the specific connection terminal is disposed near an end in a direction in which the plurality of electrode terminal portions or the plurality of connection terminals are arranged. Wiring board connection structure described in 1. The first wiring board has a structure in which a plurality of wirings are formed and each wiring has an electrode terminal portion at one end thereof, while the second wiring board has a plurality of wirings formed at one end of the wirings. Is formed at the same pitch as the electrode terminal portion and has a connection terminal correspondingly connected thereto, and each connection of the second wiring board to each electrode terminal portion of the first wiring board. A wiring board connection inspection method for inspecting a connection state of terminals when they are overlapped and connected in correspondence with each other,
Of the plurality of electrode terminal portions, the specific electrode terminal portion or the specific connection terminal of the plurality of connection terminals has a shape different from other electrode terminal portions or connection terminals,
The specific electrode terminal portion or the specific connection terminal includes an inspection portion in which a distance between the electrode terminal portion or the connection terminal adjacent to the specific electrode terminal portion or the connection terminal is partially reduced,
When connecting each of the plurality of connection terminals of the second wiring board to each of the plurality of electrode terminal parts of the first wiring board, via the connection terminal or the electrode terminal part in contact with the inspection portion, A method for inspecting a connection of a wiring board, comprising: inspecting whether or not there is a conduction state between the specific electrode terminal or connection terminal and the adjacent electrode terminal or connection terminal. The wirings of the first and second wiring boards are used when manufacturing or driving the inkjet head, respectively.
The inkjet head is provided with individual electrodes and piezoelectric layers corresponding to a plurality of pressure chambers, while a common internal electrode is provided for the plurality of pressure chambers with the piezoelectric layer interposed therebetween. The drive signal is supplied to the electrodes through the wirings of both the wiring boards,
The wiring connected to the specific electrode terminal portion is used when a predetermined voltage is applied between the internal electrode and the piezoelectric layer in the manufacturing process to polarize the piezoelectric layer,
The wiring board connection inspection method according to claim 8, wherein the wiring connected to the adjacent electrode terminal portion is connected to the internal electrode. The wirings of the first and second wiring boards are used when manufacturing or driving the inkjet head, respectively.
The inkjet head is provided with individual electrodes and piezoelectric layers corresponding to a plurality of pressure chambers, while a common internal electrode is provided for the plurality of pressure chambers with the piezoelectric layer interposed therebetween. The drive signal is supplied to the electrodes through the wirings of both the wiring boards,
The wiring connected to the specific connection terminal is connected to the internal electrode,
The wiring connected to the adjacent connection terminal is used when a predetermined voltage is applied between the internal electrode and the piezoelectric layer in a manufacturing process to polarize the piezoelectric layer. The wiring board connection inspection method according to claim 8.

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