JP2015173178A - Flexible wiring board, package structure, and liquid jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible wiring board which achieves excellent fracture resistance against bending.SOLUTION: A flexible wiring board includes: wiring 56 which is formed extending; a terminal 55 which is electrically connected with the wiring 56 and is mounted connected with an electrode terminal 81 at the exterior by solder; a bending part 58 which bends in a direction that intersects with an extension direction of the wiring 56; and a width extension part 57 which is provided in the wiring 56a between the bending part 58 and the terminal 55 and is formed wider than a width of the wiring 56a at the terminal 55 side.

Description

  The present invention relates to a flexible wiring board, a mounting structure, and a liquid jet head.

  2. Description of the Related Art Conventionally, a flexible wiring board (also referred to as a flexible printed board) that can be bent and mounted even in a narrow space is often used against the background of miniaturization and high density of electronic devices. An example of a device in which a flexible wiring board is used is a liquid ejecting head that causes pressure fluctuation in ink in a pressure generating chamber by applying a voltage to a piezoelectric element, thereby ejecting ink from a nozzle opening (for example, Patent Document 1).

  As such a flexible wiring board, for example, a flexible printed board having a flexible wiring pattern in which a flexible electrode connected to a soldering electrode on the printed board is formed at the tip has been proposed (for example, see Patent Document 2). ).

JP 2007-12661 A Japanese Patent Laid-Open No. 11-17298

  However, when soldering another electrode and a flexible wiring board, depending on conditions such as the amount of solder, applied pressing force, heat, etc., the solder flows out onto the wiring heated by the residual heat, and the bent portion is There was a risk that the solder would solidify so as to straddle. When the flexible wiring board is bent under such a situation, stress concentrates on the solder and cracks are generated, resulting in board breakage or disconnection. Such a problem exists not only in the flexible wiring board used in the liquid ejecting head but also in the flexible wiring board used in other electronic devices.

  SUMMARY An advantage of some aspects of the invention is that it provides a flexible wiring board, a mounting structure, and a liquid jet head that are excellent in breakage resistance against bending.

An aspect of the present invention that solves the above problems includes a wiring formed to extend, a terminal that is electrically connected to the wiring and is mounted by an external electrode terminal and solder, and a direction in which the wiring extends. A bent portion that is bent in the intersecting direction, and a widened portion that is provided in the wiring between the bent portion and the terminal and is formed thicker than the width of the wiring on the terminal side. The flexible wiring board is characterized.
According to this aspect, even when the solder flows between the external electrode terminal and the terminal of the flexible wiring board on the wiring, the progress of the solder can be suppressed at the widened portion. Therefore, an adverse effect due to the formation of solder on the wiring can be avoided, and a flexible wiring board having excellent resistance to bending can be provided.

  Here, it is preferable that the widened portion is formed thicker than the terminal. According to this, since the widened portion is formed thicker than the terminal formed wide for bonding with the external electrode terminal, it is possible to reliably suppress the progress of the solder in the widened portion. Therefore, it is possible to provide a flexible wiring board having excellent resistance to bending.

  Moreover, it is preferable that the said wide part is thickly formed in the width direction both sides of the said wiring by the side of the said terminal. According to this, since the solder flowing out on the wiring can be spread into the widened portion so as to spread on both sides in the width direction, the progress of the solder can be reliably suppressed in the widened portion. Therefore, it is possible to provide a flexible wiring board having excellent resistance to bending.

  The length from the terminal side end of the widened portion to the bent portion is set to be equal to or less than the length from the terminal side end of the widened portion to the tip of the terminal. preferable. According to this, the length from the widened portion to the bent portion is relatively close, and even in such an aspect, the progress of the solder can be suppressed in the widened portion. Therefore, it is possible to provide a flexible wiring board that can cope with bending in a narrow place and has excellent fracture resistance against bending.

  Further, the wiring on the terminal side includes a width-decreasing portion that is narrower than at least one of the width of the terminal and the width of the wiring in the connecting portion with the terminal, It is preferable that a portion adjacent to the bent portion side is the widened portion. According to this, the widened part of various aspects can be realized. Therefore, it is possible to provide a flexible wiring board with a high degree of freedom in configuration and excellent resistance to bending.

  Another aspect of the present invention that solves the above problems includes an extended wiring, a terminal connected to the wiring, and a bent portion that is bent in a direction intersecting with the extending direction of the wiring. A flexible wiring board provided with an electrode terminal, and a widened part formed wider than the width of the wiring on the terminal side provided in the wiring between the bent part and the terminal Mounting by soldering, wherein the solder is provided so as to be spread over the electrode terminal of the wiring board, the terminal of the flexible wiring board, and the widened portion. In addition, the solder end portion is disposed on the terminal side with respect to the bent portion, and is disposed in the widened portion. According to this aspect, it is possible to provide a mounting structure having excellent durability at the bent portion.

  Still another aspect of the present invention that solves the above-described problems includes a wiring formed to extend, a terminal connected to the wiring, and a bent portion that is bent in a direction intersecting with a direction in which the wiring extends. And a widened portion formed wider than the width of the wiring on the terminal side provided in the wiring between the bent portion and the terminal, and mounted on the flexible wiring substrate. Accordingly, a signal is supplied to a drive circuit that generates pressure in a pressure generation chamber that communicates with a nozzle opening that ejects liquid. According to this aspect, it is possible to provide a liquid jet head that is excellent in durability at the bent portion.

2A and 2B illustrate a flexible wiring board and a recording head according to Embodiment 1. 2A and 2B are a plan view and a cross-sectional view illustrating a flexible wiring board according to the first embodiment. FIG. 3 is a view for explaining the operation of solder on the flexible wiring board according to the first embodiment. The top view explaining the flexible wiring board concerning other embodiments. The top view explaining the flexible wiring board concerning other embodiments. FIG. 3 is a diagram illustrating a schematic configuration of a recording apparatus on which the recording head according to the first embodiment is mounted.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(Embodiment 1)
FIG. 1A is a schematic view of a flexible wiring board according to Embodiment 1 of the present invention, and FIG. 1B is an ink jet recording head which is an example of a liquid jet head on which the flexible wiring board is mounted. FIG.

  As shown in the figure, a driving circuit 200 such as a semiconductor integrated circuit (IC) is mounted on the flexible wiring substrate 410 by COF. In the flexible wiring board 410, for example, a predetermined wiring pattern is formed on a surface of an insulating base substrate 53 such as polyimide using a metal material such as gold (Au) or copper (Cu), and regions other than the wiring pattern are insulated. It is configured as being covered with a material 54. The flexible wiring board 410 is bent at a bent portion 58 indicated by a one-dot chain line in the drawing, and a plurality of terminals (terminals 55 shown in FIG. 2 and the like) are arranged at one end of the bent portion. A plurality of terminals arranged on one end side are connected to a plurality of electrode terminals 81 that are connection terminal portions of the wiring board 500 by soldering, and the other end side is connected to the recording head 1. Here, the drive circuit 200 is mounted on the central portion of the flexible wiring board 410 and has an outer shape having a pair of long sides extending in the width direction of the flexible wiring board 410.

  A row of electrode pads (and bumps electrically connected thereto) arranged along each long side is provided on a surface which is a mounting surface / active surface (a surface facing the flexible wiring board 410) of the drive circuit 200. Is provided. An electrode pad (bump) provided on one side of the pair of long sides serves as an input side to which signals and voltages are input from the wiring board 500 side, and the insulating base substrate 53 of the flexible wiring board 410. Each is electrically connected to a plurality of wirings provided above and led to the terminal. In addition, an electrode pad (bump) provided on the other side of the pair of long sides is an output side for driving and controlling a piezoelectric element 300 described later, and the insulating base substrate 53 of the flexible wiring board 410. A plurality of wirings provided above are electrically connected to each other and led to a plurality of terminals arranged on the other end side.

  In the flow path forming substrate 10 of the recording head 1 on which such a flexible wiring board 410 is mounted, a plurality of pressure generating chambers 12 partitioned by partition walls are arranged in parallel in the width direction of the flexible wiring board 410. It is configured, and two rows are provided. A nozzle plate 20 having a nozzle opening 21 communicating with each pressure generating chamber 12 is bonded to one side of the flow path forming substrate 10, and vibration is applied to the other side of the flow path forming substrate 10. A plate 50 is formed. The diaphragm 50 includes, for example, an elastic film 51 formed on the flow path forming substrate 10 and an insulator film 52 formed on the elastic film 51, but is not limited to the above example.

  A first electrode 60 having a thickness of about 0.2 μm and a thickness of about 3.0 μm or less, preferably about 0. A piezoelectric element 300 including a piezoelectric layer 70 having a thickness of 5 to 1.5 μm and a second electrode 80 having a thickness of about 0.05 μm is formed. These thicknesses are examples and are not limited to the above examples.

  In the present embodiment, the piezoelectric element 300 and the diaphragm 50 act as an actuator device, and the diaphragm 50 and the first electrode 60 act as a diaphragm, but are not limited to the above example. Only one of the first electrodes 60 may act as a diaphragm without providing either or both of the elastic film 51 and the insulator film 52. Further, the piezoelectric element 300 itself may substantially serve as a diaphragm. When the first electrode 60 is directly provided on the flow path forming substrate 10, the first electrode 60 can be protected with an insulating protective film or the like so that the first electrode 60 and the ink are not conducted.

  The first electrode 60 and the second electrode 80 are not particularly limited as long as they are conductive materials, and a noble metal such as platinum (Pt) or iridium (Ir) can be used. A lead electrode 90 made of gold (Au) or the like is connected to one end of the second electrode 80. For the piezoelectric layer 70, a piezoelectric material exhibiting an electromechanical conversion action, particularly a piezoelectric material made of a complex oxide having a perovskite structure can be used. Examples of such a piezoelectric material include a ferroelectric material such as lead zirconate titanate (PZT), and a material obtained by adding a metal oxide such as niobium oxide, nickel oxide, or magnesium oxide. In addition, a lead-free piezoelectric material such as a composite oxide containing bismuth (Bi), iron (Fe), barium (Ba), and titanium (Ti) and having a perovskite structure may be used.

  On the flow path forming substrate 10 on which such a piezoelectric element 300 is formed, that is, on the first electrode 60, the elastic film 51, the insulator film 52, and the lead electrode 90, the protective substrate 30 is interposed via the adhesive 35. It is joined. A compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the protective substrate 30. In addition, a piezoelectric element holding portion 32 having a space that does not hinder the movement of the piezoelectric element 300 is provided in a region of the protective substrate 30 facing the piezoelectric element 300. The protective substrate 30 is provided with a through hole 33 that penetrates the protective substrate 30 in the thickness direction. In the present embodiment, the through hole 33 is provided between the two piezoelectric element holding portions 32. The vicinity of the end portion of the lead electrode 90 drawn from each piezoelectric element 300 is provided so as to be exposed in the through hole 33.

  The flexible wiring board 410 is mounted with a plurality of terminals provided on the other end side (the side opposite to the one end) connected to the lead electrode 90, and is bent to be normal to the diaphragm. The flexible wiring board 410 disposed in the through hole 33 in a state of standing up in the direction has flexibility and can be bent and mounted even in a narrow space. Therefore, the recording head 1 and other electronic devices can be mounted. It is advantageous for miniaturization and high density.

  The terminal provided on the other end of the flexible wiring substrate 410 and the lead electrode 90 are conductive particles (for example, anisotropic conductive material such as anisotropic conductive film (ACF) or anisotropic conductive paste (ACP)). That are electrically connected to each other). That is, the heated crimping tool (head) is lowered and pressed at the tip, thereby pressing the terminal provided on the other end side of the flexible wiring board 410 toward the lead electrode 90. As a result, the conductive particles are crushed and a predetermined electrical connection is made between the flexible wiring board 410 and the lead electrode 90. However, the connection between the other end side of the flexible wiring board 410 and the lead electrode 90 is not limited to the conductive particles, and for example, a metal material such as solder may be melted and connected.

  On the compliance substrate 40, a head case 110, a main body member 130, and a wiring substrate 500 are sequentially stacked, and an electrode terminal 81 is provided on the wiring substrate 500. The wiring substrate 500 is disposed opposite to the actuator device and the flow path forming substrate, and one end of the flexible wiring substrate 410 is on the opposite side of the wiring substrate 500 from the side on which the actuator device and the flow path forming substrate are disposed. Derived and bent. A plurality of terminals provided on one end side of the flexible wiring board 410 are respectively joined to the plurality of electrode terminals 81 of the wiring board 500 by soldering. As described above, the recording head 1 of the present embodiment is configured to supply a signal to the drive circuit 200 that generates pressure in the pressure generation chamber 12 that communicates with the nozzle opening 21 that ejects the liquid by the flexible wiring board 410. Has been.

  Here, the structural example of the flexible wiring board of this embodiment is explained in full detail using Fig.2 (a)-(b). 2A is a plan view of the flexible wiring board 410 on the side where the drive circuit 200 is mounted, and FIG. 2B is a cross-sectional view corresponding to the line AA ′ in FIG. FIG.

  The flexible wiring board 410 crosses the extending direction of the wiring 56, the wiring 56 formed so as to extend, the terminal 55 electrically connected to the wiring 56, and mounted with the external electrode terminal 81 and solder. And a bent portion 58 that is bent in the direction. That is, in the flexible wiring board 410, a plurality of wirings 56 are arranged in parallel. Hereinafter, the parallel arrangement direction of the wirings 56 is referred to as a width direction or a first direction X, and the length direction of the wirings 56 (a direction perpendicular to the first direction X) is referred to as a second direction Y.

  Here, in the flexible wiring board 410 of the present embodiment, the widening formed in the wiring between the bent portion 58 and the terminal 55 (hereinafter, the terminal-side wiring 56a) and formed wider than the width of the terminal-side wiring 56a. A portion 57 is provided. According to this, even if the solder flows between the electrode terminal 81 and the flexible wiring board 410 on the terminal side wiring 56a, the progress of the solder is suppressed at the widened portion 57 before reaching the bent portion 58. Can do. Therefore, it is possible to avoid the formation of solder so as to straddle the bent portion 58, and the flexible wiring board 410 having excellent resistance to bending can be obtained.

  In the flexible wiring board 410, the widened portion 57 is formed thicker than the terminal 55. Since the terminal 55 is formed thicker than the terminal-side wiring 56a, the soldering operation between the electrode terminal 81 and the flexible wiring board 410 is facilitated. And since the widened part 57 is formed thicker than the terminal 55 formed so thickly, the progress of the solder can be reliably suppressed by the widened part 57.

  The widened portion 57 is formed thicker than the terminal-side wiring 56a, which is the wiring 56 connected to the widened portion 57 from the terminal 55 side, and is formed wide as in the present embodiment. The terminal 55 that may be generated is not included in the widened portion 57. The widened portion 57 is formed thicker in relation to the portion 56b immediately before being electrically connected to the widened portion 57 in the terminal side wiring 56a. The boundary between the terminal 55 and the terminal-side wiring 56a is not necessarily clarified.

  In the flexible wiring board 410, the widened portion 57 is formed thick on both sides in the width direction (first direction X) of the terminal side wiring 56a. According to this, since the solder flowing out on the terminal side wiring 56a can be penetrated into the widened portion 57 so as to spread on both sides in the width direction, the progress of the solder can be reliably suppressed by the widened portion 57. .

  In the flexible wiring board 410 described above, the width, length, position, shape, and the like of the terminal 55, the terminal-side wiring 56a, the widened portion 57, and the like can be appropriately designed according to the use of the flexible wiring board 410 and the like. . When the length from the terminal 55 to the bent portion 58 is excessively long, that is, even if the solder flows out onto the wiring heated by the residual heat, the solder can be solidified before reaching the bent portion 58. When the wiring length is secured, it is difficult to form and solidify the solder so as to straddle the bent portion 58. On the other hand, the flexible wiring board 410 of the present embodiment has a mode in which the length from the terminal 55 to the bent portion 58 is relatively close, and the allowable range of solder flowing out from the terminal 55 is small. In such an embodiment, the widened portion 57 is extremely meaningful.

  Hereinafter, the length in the width direction of the widened portion 57 is referred to as AX, and the length in the direction perpendicular to the width direction of the widened portion 57 (second direction Y) is referred to as AY. The length in the width direction of the terminal side wiring 56a is referred to as BX, and the length in the direction perpendicular to the width direction of the terminal side wiring 56a (second direction Y) is referred to as BY. The length in the width direction of the terminal 55 is referred to as CX, and the length in the direction perpendicular to the width direction of the terminal 55 (second direction Y) is referred to as CY. The length in the width direction of the wiring (bending portion side wiring 59) from the widened portion 57 to the bending portion 58 is DX, and the direction perpendicular to the width direction of the bending portion side wiring 59 (second direction Y). Is called DY.

  In the flexible wiring board 410, the length (AY + DY) from the end of the widened portion 57 on the terminal 55 side to the bent portion 58 is the length from the end of the widened portion 57 on the terminal 55 side to the tip of the terminal 55 ( CY + BY) or less. As described above, the length from the widened portion 57 to the bent portion 58 is relatively close, and even in such an aspect, the progress of the solder can be suppressed by the widened portion 57.

  The relationship between the width and length of the terminal 55, the terminal-side wiring 56a, the widened portion 57, and the like is, for example, (AX) ≧ (BX) × 1.5, (CY + BY) ≧ BX, or (AY + BY + CY + DY) ≦ 5 mm. You can also Even in this aspect, the progress of the solder can be suitably suppressed by the widened portion 57.

  Further, in the flexible wiring substrate 410, a groove 61 is formed on the side opposite to the insulating material 54 along a position where the bent portion 58 is a mountain fold. According to this, since the flexible wiring board 410 can be accurately bent along the groove 61, the flexible wiring board 410 can be bent across the widened portion 57 or the solder existing on the terminal 55 side during mounting. Can be prevented.

  Next, the function of the flexible wiring board according to the present embodiment will be described in detail with reference to FIGS. FIGS. 3A to 3C are cross-sectional views of the flexible wiring board 410 and are diagrams for explaining the flow of the solder H during mounting on the electrode terminal 81.

  As shown in FIG. 3A, when soldered for bonding to the electrode terminal 81 of the wiring board 500, not only the terminal 55 but also the terminal-side wiring 56a is heated by residual heat, and FIG. As shown in b), excess solder flows out toward the widened portion 57. Then, as shown in FIG. 3C, when flowing into the widened portion 57, the progress of the solder is suppressed, and the solder is solidified in the widened portion 57 before long.

  Thus, the principle that the progress of the solder can be suppressed by the widened portion 57 before reaching the bent portion 58 is not necessarily clear, but since the widened portion 57 is wider than the terminal side wiring 56a, the flexible wiring board As a result, the contact area of the solder H with respect to 410 increases, and as a result, the surface tension caused by the height C of the solder H on the terminal-side wiring 56 a greatly changing to the height D of the solder H on the widened portion 57. It is guessed that this is due to changes in Further, since the capillary force of the solder flowing out on the terminal side wiring 56a is inversely proportional to the radius of the solder, it is caused by a decrease in the capillary force resulting from the fact that the solder radius is reduced by flowing out on the widened portion 57. It is also inferred. Further, it can be inferred that since the widened portion 57 is wider than the terminal-side wiring 56a, the heat radiation effect becomes easier to work and the solidification of the solder H is promoted.

  The mounting structure configured as described above includes an extended wiring 56, a terminal 55 connected to the wiring 56, and a bent portion 58 that is bent in a direction crossing the extending direction of the wiring 56. A flexible wiring board 410 including a widened portion 57 formed thicker than the width of the terminal-side wiring 56a provided in the wiring (terminal-side wiring 56a) between the bent portion 58 and the terminal 55. In this mounting structure, the solder is mounted on the wiring board 500 including the terminals 81 by soldering, and the solder is spread over the electrode terminals 81 of the wiring board 500, the terminals 55 and the widened portion 57 of the flexible wiring board 410. The end portion of the solder that is provided and spread out is disposed closer to the terminal 55 than the bent portion 58 and disposed in the widened portion 57. With such a mounting structure, it is possible to provide a mounting structure with excellent durability at the bent portion even if lead-free solder, which is a type of solder that is considered to be relatively easily broken.

  Note that the amount of solder flowing out from the terminal 55 toward the bent portion 58 may vary depending on conditions such as the amount of solder, the applied pressing force, and heat. Therefore, the mounting structure of this embodiment does not necessarily require that the solder is arranged from all the terminals 55 to the inside of the widened portion 57 among the plurality of terminals 55. It is theoretically possible to prevent the solder from flowing out from the joint between the electrode terminal 81 and the terminal 55 if the above conditions are adjusted very strictly. However, if the above-mentioned flexible wiring board 410 is used. Thus, a simple joining method in which it is not necessary to strictly adjust such conditions can be adopted, and an electronic device such as a mounting structure and a liquid ejecting head excellent in durability at the bent portion 58 can be obtained.

(Other embodiments)
As mentioned above, although each embodiment of this invention was described, the fundamental structure of this invention is not limited to what was mentioned above. Hereinafter, a configuration example of a flexible wiring board according to another embodiment will be described. Such a flexible wiring board according to another embodiment can basically be configured based on the same concept as the flexible wiring board 410 according to the first embodiment with respect to its configuration and AX to DX and AY to DA. The following description will focus on the different parts.

  For example, it is not essential to have the terminal 55 formed thicker than the terminal-side wiring 56a, and the terminal formed thicker is not provided like the flexible wiring board 410A shown in FIG. It is good also as such a structure. In this case, the end of the terminal side wiring 56a opposite to the bent portion 58 functions as a terminal 55a having the same width as the terminal side wiring 56a, and the terminal side wiring 56a has a length (BY) that is a terminal. A length (CY) of 55a is included.

  Further, as in the flexible wiring board 410B shown in FIG. 4B, the terminal 55b formed thicker than the first embodiment and the terminal-side wiring 56c having the same width as the terminal 55b may be provided. Good. In this case, the length (CY) of the terminal side wiring 56c is included in the length (CY) of the terminal 55b.

  Further, as in the flexible wiring board 410C shown in FIG. 4C, a plurality of widened portions 57 are provided, and the adjacent widened portions 57 have different lengths from the terminals 55, that is, the widened portions 57 are staggered. It is good also as a structure arrange | positioned in a shape. According to this, it becomes easy to arrange a plurality of terminal side wirings 56a densely. And even if it is the aspect by which the several terminal side wiring 56a is arrange | positioned densely, progress of a solder can be suppressed by the wide part 57. FIG. Therefore, it is possible to provide the flexible wiring board 410C in which the plurality of terminal-side wirings 56a can be densely arranged and has excellent resistance to bending. 4A to 4C as described above, the widened portion 57 is the portion 56b immediately before being electrically connected to the widened portion 57 of the terminal side wirings 56a and 56c. It is formed thick because of the relationship.

  5A, the terminal-side wiring 56d is narrower than at least one of the width of the terminal 55 and the width of the wiring 56 at the connection portion with the terminal 55. It is good also as a structure which comprises the reduced part 62. FIG. Such a reduced width portion 62 is formed by disposing the insulating material 54 in at least a part of the wiring 56 that is electrically connected to the terminal 55 or by forming a recess 63 that is not electrically connected to the wiring 56. The latter can be used here.

  Before the recess 63, the terminal-side wiring 56d branches, and as a result, the terminal-side wiring 56d on both sides in the second direction Y of the recess 63 functions as the reduced width portion 62. The terminal-side wiring 56d serving as the reduced width portion 62 functions as the immediately preceding portion 56b that is electrically connected to the widened portion 57, and the portion where the terminal-side wiring 56d joins functions as the widened portion 57a. It becomes. According to this, for example, after the terminal 55, the widened portion 57a can be obtained without forming the terminal side wiring 56a thick.

  The present invention is not limited to the above example, and a wiring that is electrically connected to the terminal 55 is formed thick as in the flexible wiring board 410E shown in FIG. 63 may be formed. Also by this, the terminal side wiring 56e on both sides in the second direction Y of the recess 63 functions as the reduced width portion 62, and the terminal side wiring 56e that becomes the reduced width portion 62 is electrically connected to the widened portion 57a. The portion 56b functions as the immediately preceding portion 56b, and the portion that is closer to the bent portion 58 than the recess 63 and where the terminal-side wiring 56e joins functions as the widened portion 57a.

  In the case shown in FIGS. 5A and 5B, the width of the terminal side wirings 56d and 56e branched by the recess 63 is BX, and the width of the part where the terminal side wirings 56d and 56e merge. Is AX. Further, AY which is the length of the widened portion 57 a is included in the length DY of the terminal 55 from the widened portion 57 a to the bent portion 58. If the length in the second direction Y of the wiring between the terminal 55 and the reduced width portion 62 is EY, the total length on the terminal 55 side with respect to the bent portion 58 is CY + EY + BY + AY (DY).

  The reduced width portion 62 is not limited to the embodiment using the recessed portion 63, and a reduced width portion 62a that is discontinuously narrowed from both sides in the first direction X as in the flexible wiring board 410F shown in FIG. It is good also as a structure which comprises. Moreover, it is good also as a structure which comprises the reduced width part 62b which becomes narrow continuously from the both sides in the 1st direction X like the flexible wiring board 410G shown in FIG.5 (d). In the case shown in FIGS. 5C to 5D, the widths of the terminal side wirings 56f and 56g in the portions that become the reduced width portions 62a and 62b are set to BX, and the portions that become the reduced width portions 62a and 63b. The length of the terminal side wirings 56f and 56g is BY. And the width of the wiring of the part adjacent to the bending part 58 side of terminal side wiring 56f, 56g is set to AX. 5A to 5D as described above, the widened portion 57a is the portion 56b immediately before being electrically connected to the widened portion 57a among the terminal side wirings 56d to 56g. It is formed thick because of the relationship.

  In addition, when the flexible wiring board is viewed in plan, a configuration in which the widened portion is tapered, a configuration in which the widened portion is curved, and a configuration in which the widened portion is stepped are adopted. Also good. In these cases, the maximum width can be treated as AY. A plurality of widened portions may be formed along the second direction Y. In this case, the sum of the lengths of the widened portions can be handled as the AY of the widened portion. In addition to this, a widened portion with a wider width on one side in the first direction X and a reduced width portion with a narrowed width on one side may be configured, and the wiring along the second direction Y may be configured. A plurality of widened portions and reduced width portions may be provided on the top.

  As described above, according to each embodiment of the present invention, it is possible to avoid a bad influence caused by the formation of solder on the wiring, and to provide a flexible wiring board having excellent resistance to bending. Furthermore, according to each embodiment of this invention, the suitable aspect according to the use etc. for which a flexible wiring board is used is realizable. Each embodiment can be combined.

  Although the embodiments of the present invention have been described, the basic configuration of the present invention is not limited to the above-described one. For example, when the flexible wiring board 410 and the lead electrode 90 are joined by soldering without being limited to the joining of the flexible wiring board 410 and the electrode terminal 81, the mounting structure of the present invention is also adopted at the joining portion. can do. When the joint between the flexible wiring board 410 and the semiconductor integrated circuit is also joined by soldering, the mounting structure of the present invention can be employed.

  Furthermore, the present invention is intended for a wide range of mounting structures capable of mounting a flexible wiring board and thus electronic components. For example, recording heads such as various ink jet recording heads used in image recording apparatuses such as printers, liquid crystals Driving color material ejecting heads used for manufacturing color filters such as displays, organic EL displays, electrode material ejecting heads used for forming electrodes such as FEDs (field emission displays), and bio-organic matter ejecting heads used for biochip manufacturing The method can also be applied. Furthermore, the present invention can also be applied to a recording head using a bulk piezoelectric element that is not a thin film.

  The recording heads of these embodiments constitute a part of a recording head unit including an ink flow path communicating with an ink cartridge and the like, and are mounted on a liquid ejecting apparatus (inkjet recording apparatus). FIG. 6 is a schematic view showing an example of the ink jet recording apparatus.

  As shown in the drawing, in an ink jet recording apparatus I which is an example of a liquid ejecting apparatus, in an ink jet recording head unit (head unit) II having a plurality of recording heads, cartridges 2A and 2B constituting ink supply means can be attached and detached. Is provided. The carriage 3 on which the head unit II is mounted is provided on a carriage shaft 5 attached to the apparatus main body 4 so as to be axially movable. For example, a black ink composition and a color ink composition are ejected, respectively. .

  Then, the driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and timing belt 7 (not shown), and the carriage 3 on which the head unit II is mounted is moved along the carriage shaft 5. Yes. On the other hand, the apparatus main body 4 is provided with a conveyance roller 8 as a conveyance means, and a recording sheet S which is a recording medium such as paper is conveyed by the conveyance roller 8. The conveying means for conveying the recording sheet S is not limited to the conveying roller, and may be a belt, a drum, or the like.

  In such an ink jet recording apparatus I, since the recording head of this embodiment is mounted as a liquid jet head, the mounting structure of the flexible wiring board is excellent in durability at the bent portion. Therefore, even if vibration is applied every time the carriage moves along the carriage shaft 5, the substrate is not easily broken or disconnected.

I ink jet recording apparatus (liquid ejecting apparatus), II head unit, 1 ink jet recording head (liquid ejecting apparatus), 10 flow path forming substrate, 12 pressure generating chamber, 20 nozzle plate, 21 nozzle opening, 30 protective substrate, 32 Piezoelectric element holder, 33 through-hole, 35 adhesive, 40 compliance substrate, 41 sealing film, 42 fixing plate, 50 vibration plate, 51 elastic film, 52 insulator film, 53 insulating base substrate, 54 insulating material, 55, 55a, 55b terminal, 56 wiring, 56a, 56c, 56d, 56e, 56f, 56g terminal side wiring, 56b immediately preceding part, 57, 57a widened part, 58 bent part, 59 wiring (bent part side wiring), 60th 1 electrode, 61 groove, 62, 62a, 62b reduced width part, 63 recessed part, 70 piezoelectric layer, 80 second electrode, 81 electrode terminal, 90 lead electrode, 110 head case, 130 body member, 200 drive circuit, 300 piezoelectric element, 400 holding member, 410, 410A to 410G flexible wiring board, 500 wiring board ,

Claims (7)

An extended wiring, and
A terminal electrically connected to the wiring and mounted by external electrode terminals and solder;
A bent portion that is bent in a direction crossing the extending direction of the wiring;
A flexible wiring board comprising: a widened portion that is provided in a wiring between the bent portion and the terminal and is formed to be thicker than a width of the wiring on the terminal side.   The flexible wiring board according to claim 1, wherein the widened portion is formed thicker than the terminal.   The flexible wiring board according to claim 1, wherein the widened portion is formed thick on both sides in the width direction of the wiring on the terminal side.   The length from the terminal-side end of the widened portion to the bent portion is set to be equal to or less than the length from the terminal-side end of the widened portion to the tip of the terminal. The flexible wiring board according to any one of claims 1 to 3. The wiring on the terminal side includes a reduced width portion that is narrower than at least one of the width of the terminal and the width of the wiring in the connection portion with the terminal,
The flexible wiring board according to claim 1, wherein a portion adjacent to the bent portion side of the reduced width portion is the widened portion. Wiring formed to extend, a terminal connected to the wiring, a bent portion that is bent in a direction intersecting with a direction in which the wiring extends, and the gap between the bent portion and the terminal A flexible wiring board having a widened portion formed thicker than the width of the wiring on the terminal side provided in wiring, and a mounting structure for mounting the wiring board with electrode terminals by soldering,
The solder is provided wet and spread over the electrode terminal of the wiring board, the terminal of the flexible wiring board and the widened portion,
The mounting structure is characterized in that the end portion of the solder that has been spread out is disposed on the terminal side with respect to the bent portion and is disposed in the widened portion. Wiring formed to extend, a terminal connected to the wiring, a bent portion that is bent in a direction intersecting with a direction in which the wiring extends, and the gap between the bent portion and the terminal A pressure generating chamber that includes a flexible wiring board provided with a widened portion that is thicker than the width of the wiring on the terminal side provided in the wiring, and communicates with a nozzle opening that ejects liquid by the flexible wiring board. A liquid ejecting head, characterized in that a signal is supplied to a driving circuit that generates pressure on the head.

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