JP2017046089A - Flexible wiring board with seal part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the deformation of a seal part while maintaining a constant distance from the end part of a flexible wiring board in the width direction to a water cutoff part.SOLUTION: A flexible wiring board 1 with a seal part includes: a flexible wiring board 10; an annular seal part 13 formed on the circumference of the flexible wiring board 10 in the middle of the flexible wiring board 10 in the longitudinal direction; and reinforcing plates 20 and 20 disposed inside the seal part 13 to reinforce the seal part 13. Each of the reinforcing plates 20 and 20, which is a different body from the flexible wiring board 10 and composed of material having higher hardness than the seal part 13, is disposed in a position protruding to at least one width direction of the flexible wiring board 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a flexible wiring board with a seal portion provided with a seal portion functioning as a water stopping means in a part of the flexible wiring substrate.

  High waterproofness is required for electronic devices represented by recent portable communication devices. For this reason, the electronic device usually has a structure in which the inside of the housing is divided into a plurality of highly confidential spaces by a partition plate, and the connection objects in these spaces are electrically connected through a flexible wiring board.

  FIG. 4 shows a front view of a conventionally known flexible wiring board with a seal portion and an enlarged transparent view of a part X thereof. FIG. 5 shows a state (5A) in which the seal portion of FIG. 4 is normally inserted into the through hole of the partition plate and a deformed state (5B) of the seal portion immediately after the start of insertion.

  As shown in FIG. 4, a conventionally known flexible wiring board 100 with a seal portion includes connectors 112, 112 at both ends 111, 111 of the flexible wiring board 110, and the flexible wiring board 110 between the both ends 111, 111. The seal portions 113 and 113 are provided at a predetermined distance. The seal portion 113 is an elastomer molded body that covers the periphery of the flexible wiring board 110 in an annular shape. As shown in FIG. 5, the partition plate 120 that partitions the space described above has a through hole 121 through which the flexible wiring board 110 is inserted. The through hole 121 is formed in such a size that the seal portion 113 can be closely inserted while the flexible wiring board 110 is inserted. As a result, it is possible to prevent water from entering through the through hole 121 (see, for example, Patent Documents 1 and 2).

JP 2011-155234 A Japanese Patent No. 5699987

  However, the above-described conventionally known flexible wiring board 100 with a seal portion has the following problems. When the seal portion 113 is inserted into the through hole 121, as shown in FIG. 5 (5B), the seal portion 113 is deformed so as to bend in the insertion direction. For this reason, there are many cases where it is difficult to insert the seal portion 113 into the through hole 121. A method is also conceivable in which projecting portions are formed on both sides in the width direction of the flexible wiring substrate 110 and the periphery thereof is covered with the seal portion 113. However, even if the overhanging portion is formed on the flexible wiring substrate 110, it is not sufficient for preventing the deformation of the seal portion 113. Further, the accuracy of the distance a from the width direction end portion of the flexible wiring board 110 shown in FIG. 5 (5A) to the width direction end portion of the seal portion 113 is directly connected to the contact pressure to the through hole 121 of the seal portion 113. It is desired that the waterproof performance is extremely high because it determines whether the waterproof performance is good or bad.

  This invention is made | formed in view of the said subject, and it aims at reducing the deformation | transformation of a seal | sticker part and keeping the distance from the width direction edge part of a flexible wiring board to a water stop part constant.

  A flexible wiring board with a seal part according to an embodiment for achieving the above object includes a flexible wiring board, and a seal part formed in an annular shape around the flexible wiring board in the middle of the length direction of the flexible wiring board. A reinforcing plate disposed in the sealing portion to reinforce the sealing portion, and the reinforcing plate is a plate made of a material that is separate from the flexible wiring substrate and has a higher hardness than the sealing portion, and the width of the flexible wiring substrate It arrange | positions in the position which protrudes in at least any one direction.

  In the flexible wiring board with a seal portion according to another embodiment of the present invention, the reinforcing plate may be two plates disposed on both sides in the width direction of the flexible wiring board.

  In the flexible wiring board with a seal portion according to another embodiment of the present invention, a seal portion may be interposed between the reinforcing plate and the flexible wiring substrate.

  The flexible wiring board with a seal portion according to another embodiment of the present invention may further include a through hole for alignment with the flexible wiring board on the reinforcing plate.

  ADVANTAGE OF THE INVENTION According to this invention, the deformation | transformation of a seal part can be reduced and the distance from the width direction edge part of a flexible wiring board to a water stop part can be kept constant.

FIG. 1 shows a front view of a flexible wiring board with a seal portion according to an embodiment of the present invention and an enlarged transparent view of a part A thereof. 2 is a transparent side view (2A) in which the vicinity of the seal portion in FIG. 1 is transparently seen from the width direction, and a modification of the relationship between the reinforcing plate and the flexible wiring board in the same manner. A transmission side view (2B) is shown respectively. FIG. 3 shows a modification (3A, 3B) of the reinforcing plate of FIG. FIG. 4 shows a front view of a conventionally known flexible wiring board with a seal portion and an enlarged transparent view of a part X thereof. FIG. 5 shows a state (5A) in which the seal portion of FIG. 4 is normally inserted into the through hole of the partition plate and a deformed state (5B) of the seal portion immediately after the start of insertion.

  Next, each embodiment of the flexible wiring board with a seal portion according to the present invention will be described with reference to the drawings. Each embodiment described below does not limit the invention according to the scope of claims, and all the elements and combinations thereof described in each embodiment are included in the present invention. It is not always essential to the solution.

(Definition)
In the present application, the “width direction” refers to a direction orthogonal to a length direction and a thickness direction connecting between connectors or terminals of a flexible wiring board. The width direction of the seal portion is the same as the width direction of the flexible wiring board, and the length of the seal portion with respect to the length direction is not limited. The “radial direction” refers to a diameter direction when a virtual circle centered on the cross-sectional center of the flexible wiring board viewed from one side in the length direction is drawn.

(Various forms of flexible wiring board with seal part)
FIG. 1 shows a front view of a flexible wiring board with a seal portion according to an embodiment of the present invention and an enlarged transparent view of a part A thereof.

  The flexible wiring substrate with a seal portion 1 according to this embodiment includes a flexible wiring substrate 10 and a seal portion 13 formed in an annular shape around the flexible wiring substrate 10 in the middle of the length direction of the flexible wiring substrate 10. Prepare. The seal portion 13 includes two reinforcing plates 20 for reinforcing the seal portion 13 therein. The flexible wiring board 10 includes connectors 12 and 12 at both ends 11 and 11 thereof. The connectors 12 and 12 are connected by a plurality of electric wires (not shown). The plurality of electrical wirings are embedded in the flexible wiring board 10 without being in contact with each other, and are not short-circuited even if they are in contact with other flexible wiring boards 10.

  The flexible wiring board 10 is composed of a resin such as polyimide, polyester, polyamide, polyurethane, polyarylate, polyetherimide, polysulfone, polyethersulfone, fluorinated polyimide, or a polymer alloy composed of two or more of these resins. . As a constituent material of the flexible wiring board 10, a material having excellent heat resistance and high insulation is particularly preferable. The thickness of the flexible wiring board 10 is preferably in the range of 3 to 240 [mu] m, more preferably in the range of 5 to 180 [mu] m, so that the electrical wiring can be reliably embedded and sufficient flexibility is exhibited.

  The electrical wiring in the flexible wiring board 10 is made of a metal having excellent conductivity such as gold, silver, or copper, and it does not matter whether the cross section is circular or rectangular. In the case of electrical wiring having a circular cross section, the diameter is preferably in the range of 5 to 40 μm. In the case of electrical wiring having a rectangular cross section, the thickness is preferably in the range of 5 to 40 μm. Regardless of the cross-sectional shape, the electrical wiring is sized to be completely embedded in the thickness of the flexible wiring board 10. The electrical wiring is preferably formed by a method such as vapor deposition on one surface of the flexible wiring board 10 and then sandwiched by another layer. As another method, an insert molding method in which a resin material constituting the flexible wiring board 10 is supplied and cured around the electric wiring in the form of fine wires can be exemplified. However, the manufacturing method of the flexible wiring board 10 in which the electric wiring is embedded is not limited to the above method, and may be another method.

  The connector 12 is a metal having excellent conductivity, and is preferably made of a highly conductive metal (gold, silver, copper, etc.) equivalent to the electrical wiring in the flexible wiring board 10. Only the surface of the connector 12 may be covered with gold, silver or copper.

  The seal part 13 is made of silicone rubber, urethane rubber, chloroprene rubber, ethylene-propylene-diene copolymer, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polyester rubber, polybutadiene rubber, fluorine rubber, natural rubber. It is preferably made of an elastomer such as rubber. In particular, it is more preferable to use silicone rubber as the material of the seal portion 13. The hardness of the seal portion 13 is preferably A40 to 60 in terms of durometer hardness (JIS K6253). In this embodiment, the seal portion 13 has a structure in which an insertion portion 14 and a locking portion 16 that is larger in the radial direction than the insertion portion 14 are stacked in this order from the connector 12 side. Between the distal end of the insertion portion 14 and the locking portion 16, a water blocking portion 15 formed in a convex shape around the insertion portion 14 with a diameter about the middle between the insertion portion 14 and the locking portion 16. Is provided. The insertion portion 14 has a size that can be inserted into a through hole formed in a partition plate in the electronic device. The locking portion 16 has a size that cannot pass through the through hole. The water stop portion 15 is slightly larger than the through hole. For this reason, when the insertion portion 14 of the seal portion 13 is inserted into the through hole, the seal portion 13 is in close contact with the inside of the through hole at the water stop portion 15, and the seal portion 13 passes through the through hole any more at the locking portion 16. Can not.

  The reinforcing plate 20 is a plate that is separate from the flexible wiring board 10 and is made of a material having a hardness higher than that of the seal portion 13. The reinforcing plate 20 more preferably has a hardness equal to or higher than that of the flexible wiring board 10. The reinforcing plate 20 is disposed at a position protruding in at least one of the width direction of the flexible wiring board 10 (the direction perpendicular to the direction of the connector 12 and the thickness direction). In this embodiment, the reinforcing plates 20 are arranged one by one on both sides in the width direction of the flexible wiring board 10 with a gap from the flexible wiring board 10. The reinforcing plate 20 is preferably completely embedded in the seal portion 13 so as not to disturb the sealing performance of the seal portion 13.

  The reinforcing plate 20 is separate from the flexible wiring board 10 and is made of a material having a hardness higher than that of the seal portion 13. As a constituent material of the reinforcing plate 20, resins such as polyimide, polyamide, polycarbonate, polyethylene terephthalate, polybutylene terephthalate; silicone rubber, urethane rubber, chloroprene rubber, ethylene-propylene-diene copolymer, styrene-butadiene copolymer, Elastomers such as acrylonitrile-butadiene copolymer, polyester rubber, polybutadiene rubber, fluorine rubber, and natural rubber; metals represented by SUS, nickel, copper, iron, or alloys of two or more thereof; alumina, carbonized Examples thereof include ceramics represented by silicon and silicon nitride; graphite; and glass. Even if the reinforcing plate 20 is made of the same material as the flexible wiring board 10, it preferably has a hardness equal to or higher than that of the flexible wiring board 10. When the reinforcing plate 20 is made of resin, for example, it is preferable to use polyimide of about R126 or polycarbonate of about M78 by measuring Rockwell hardness according to JIS K7202. The Rockwell hardness increases in the order of R scale <L scale <M scale. The polyimide and polycarbonate reinforcing plates 20 having the above hardness have a hardness exceeding A85 defined by the durometer hardness (JIS K6253) of the elastomer constituting the seal portion 13.

  2 is a transparent side view (2A) in which the vicinity of the seal portion in FIG. 1 is transparently seen from the width direction, and a modification of the relationship between the reinforcing plate and the flexible wiring board in the same manner. A transmission side view (2B) is shown respectively.

  The reinforcing plate 20 shown in (2A) is disposed in the seal portion 13 in the width direction of the flexible wiring board 10. The reinforcing plate 20 is not fixed to the flexible wiring board 10 but is fixed by a seal portion 13 that covers the periphery thereof. Since the reinforcing plate 20 is disposed so as to protrude in the width direction of the flexible wiring substrate 10 in the seal portion 13, the seal portion 13 is hardly deformed in the width direction.

  In addition to the form (2A), a modification example shown in (2B) may be adopted. In the gap between the reinforcing plate 20 and the flexible wiring board 10 shown in (2B), a seal portion 13 is interposed, and a silane coupling agent 21 is applied to the surface of the reinforcing plate 20. This is to improve the adhesive force between the reinforcing plate 20 and the seal portion 13.

  FIG. 3 shows a modification (3A, 3B) of the reinforcing plate of FIG.

  The reinforcing plate 30 shown in (3A) has the same shape as the reinforcing plate 20 described above, but differs from the reinforcing plate 20 in that it includes through holes 31 and 32 for alignment with the flexible wiring board 10. The through holes 31 and 32 can be fixed to pins in a mold for insert molding, so that the reinforcing plate 30 does not move during molding. The through holes 31 and 32 are preferably formed at two or more locations in the reinforcing plate 30, but the formation positions thereof are not limited as long as they are formed at positions that do not overlap the water stop portion 15.

  The reinforcing plate 40 shown in (3B) has the same shape as the above-described reinforcing plate 20, but differs from the reinforcing plate 20 in that it has mesh-like irregularities 41 on at least one surface. Such unevenness 41 contributes to improving the adhesion with the seal portion 13. Note that the reinforcing plate 40 provided with the unevenness 41 may be a mesh-shaped porous plate. In that case, by providing the reinforcing plate 40 with a large number of holes (through holes), in addition to the rigidity due to the material of the reinforcing plate 40, it has flexibility. By adding flexibility to the reinforcing plate 40, it is possible to increase the tolerance of variation in the size of the through hole while ensuring the rigidity in the direction in which the seal portion 13 is inserted into the through hole of the partition plate. In particular, there is an advantage that it is easy to cope with a through hole having a shape different from that of the seal portion 13. In addition, the unevenness | corrugation 41 can also be provided in the above-mentioned reinforcement board 30. FIG.

(Operations and effects of various embodiments)
The flexible wiring board with a seal portion 1 according to each of the above-described embodiments includes a flexible wiring substrate 10 and a seal portion 13 formed in an annular shape around the flexible wiring substrate 10 in the middle of the length direction of the flexible wiring substrate 10. And reinforcing plates 20, 30, 40 (hereinafter referred to as the reinforcing plate 20) disposed in the sealing portion 13 in order to reinforce the sealing portion 13, and the reinforcing plate 20 is separated from the flexible wiring board 10. The plate is made of a material having higher hardness than the seal portion 13 and is disposed at a position protruding in at least one of the width directions of the flexible wiring board 10. Further, in the flexible wiring board 1 with a seal portion, the reinforcing plates 20 and the like can be two sheets arranged on both sides of the flexible wiring board 10 in the width direction. The reinforcing plate 20 or the like is a member different from the flexible wiring board 10 and is a member having higher hardness than the seal portion 13, so that the insertability when the seal portion 13 is inserted into the through hole of the partition plate is improved. In addition, the contact pressure between the seal portion 13 and the through hole of the partition plate can be made substantially constant after insertion. This leads to an improvement in water stoppage by the seal portion 13. In addition, by making the reinforcing plate 20 and the like separate from the flexible wiring board 10, it is possible to flexibly cope with the shape change of the seal portion 13, and it is not necessary to remanufacture to change the shape of the flexible wiring board 10 itself. It is only necessary to change the reinforcing plate 20 or the like. For this reason, advantages such as reduction in manufacturing cost and shortened delivery time can be enjoyed.

  In the flexible wiring board with a seal portion 1 according to this embodiment, the seal portion 13 can be interposed between the reinforcing plate 20 and the flexible wiring substrate 10. For this reason, the reinforcement board 20 grade | etc., Can be arrange | positioned in the outer side vicinity of the seal part 13, and the outermost deformation | transformation of the seal part 13 can be suppressed.

  The flexible wiring board with a seal portion 1 according to this embodiment can include through holes 31 and 32 for alignment with the flexible wiring board 10 in the reinforcing plate 20 or the like. Thereby, the position shift with the reinforcement board 20 grade | etc., And the flexible wiring board 10 can be reduced.

(Other embodiments)
As described above, the preferred embodiment of the flexible wiring board with a seal portion of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications can be made.

  For example, the reinforcing plate 20 or the like may be disposed in the seal portion 13 so as to protrude only on one side in the width direction of the flexible wiring board 10. Further, the reinforcing plate 20 or the like may be disposed in close contact with or fitted in the width direction of the flexible wiring board 10. Furthermore, although the two sealing parts 13 are provided in the flexible wiring board 10, the number is not limited. Moreover, the shape of the seal part 13 is not limited to the form shown in FIG. The structures of the various reinforcing plates 20 and the like described above can be combined as appropriate.

  The flexible wiring board with a seal portion according to the present invention is used, for example, for wiring for electronic equipment with waterproofness.

DESCRIPTION OF SYMBOLS 1 Flexible wiring board 10 with a seal part Flexible wiring board 13 Seal part 20, 30, 40 Reinforcement board (For example, a mesh-shaped perforated board)
31, 32 through hole

Claims (4)

A flexible wiring board;
A seal portion formed in an annular shape around the flexible wiring substrate in the middle of the length direction of the flexible wiring substrate;
A reinforcing plate disposed in the seal portion to reinforce the seal portion;
With
The reinforcing plate is a plate made of a material that is separate from the flexible wiring board and has a higher hardness than the sealing portion, and has a flexible portion with a sealing portion that is disposed at a position protruding in at least one of the width directions of the flexible wiring substrate. Wiring board.   The flexible wiring board with a seal part according to claim 1, wherein the reinforcing plates are two boards disposed on both sides in the width direction of the flexible wiring board.   The flexible wiring board with a seal part according to claim 1 or 2, wherein the seal part is interposed between the reinforcing plate and the flexible wiring board.   4. The flexible wiring board with a seal part according to claim 1, wherein the reinforcing plate includes a through-hole for alignment with the flexible wiring board. 5.

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