JP5166990B2 - Flexible circuit board and manufacturing method thereof - Google Patents

Description

  The present invention relates to a flexible circuit board (FPC) and a manufacturing method thereof, and more particularly, to an FPC having a reinforcing plate in a connection portion connected to a connector and a manufacturing method thereof.

  Conventionally, a reinforcing plate is often attached to a connecting portion connected to an FPC connector (hereinafter referred to as “connector connecting portion”) in order to ensure fitting and mechanical strength with the connector. . As the reinforcing plate, a glass-epoxy resin plate in which glass fibers are impregnated with an epoxy resin is often used from the viewpoint of punching workability and strength. Accordingly, a method is generally performed in which the reinforcing plate is bonded to the connector connecting portion and then the FPC product outer shape is punched out. However, the burrs and epoxy resin pieces of the glass fiber of the reinforcing plate are peeled off from the end of the connector connecting portion after punching of the FPC, and these adhere to the terminals of the FPC (that is, on the connector connecting portion) It may enter between the mating connector contacts and cause poor contact at the connector connection. This will be described with reference to the drawings.

  FIG. 4 is a cross-sectional view of a connector connecting portion in a conventional FPC. As shown in the figure, an FPC 14 is formed by coating a cover film 13 on the surface of a circuit metal foil 12 patterned on an insulating base 11, and the front side of the connector connecting portion 15 at the tip of the FPC 14 is a circuit metal foil. Nickel / gold plating 16 is applied to the surface of 12, and a reinforcing plate 18 is bonded to the back side of the connector connecting portion 15 via an adhesive 17.

  When the product outer shape of the FPC 14 having such a configuration is punched out, the distal end portion of the connector connecting portion 15 is cut off with a predetermined dimensional accuracy. At this time, the burrs 19 and the epoxy resin pieces 20 of the glass fiber of the reinforcing plate 18 are peeled off from the end of the connector connecting portion 15 after the punching process of the FPC 14, and these burrs 19 and the epoxy resin pieces are indicated by broken lines. 20 may adhere on the connector connecting portion 15 and may enter between the mating connector contact (not shown) and cause contact failure in the connector connecting portion 15.

  FIG. 5 is a top view of a connector connecting portion in a conventional FPC. As shown in the figure, the circuit metal foil 12 which is a terminal portion of the connector connecting portion 15 is subjected to a surface treatment such as nickel / gold plating (not shown in FIG. 4) in order to ensure surface protection and conduction reliability. Is given. When the nickel / gold plating is plated on the surface of the circuit metal foil 12 by the electrolytic plating method, the plating lead 21 is required to supply the plating current to the circuit metal foil 12. The plated lead 21 has a tip connected to a metal frame (not shown). When the outer shape of the FPC 14 is punched, the metal frame is cut off, but a part of the plated lead 21 is a circuit metal. It remains at the end of the foil 12.

  FIG. 6 is a cross-sectional view when a connector connecting portion in a conventional FPC is inserted into a connector. That is, if a part of the plating lead 21 remains at the end of the circuit metal foil 12 of the connector connecting portion 15 as shown in FIG. 5 described above, the connector connecting portion 15 of the FPC 14 is connected as shown in FIG. When inserted to the connector side as indicated by an arrow, the plating lead 21 may come into contact with the connector connector 22, and the tip portion of the circuit metal foil 12 may be peeled off from the insulating base 11 together with the plating lead 21.

  Therefore, in order to solve the problem that the glass fiber burrs and epoxy resin pieces of the reinforcing plate adhere to the connector connection part and cause a contact failure and the problem that the tip part of the circuit metal foil peels off from the insulating base, A technique is disclosed in which the tip portion of the taper is tapered and the plating lead extends obliquely from the terminal portion of the circuit metal foil (see, for example, Patent Document 1). According to this technique, the tip end portion of the connector connecting portion is tapered, and the plating lead extends obliquely from the terminal portion of the circuit metal foil, so that the plating lead does not hit the connector connector when the connector is inserted. Therefore, it is possible to avoid peeling of the circuit metal foil from the insulating base.

  In addition, in order to form a tapered shape as disclosed in Patent Document 1 at the distal end portion of the connector connecting portion, the distal end portion of the connector connecting portion is shaved by polishing or the like. Glass fiber burrs and epoxy resin pieces generated during the punching process are also polished and removed together. Therefore, there is no possibility that the glass fiber burrs or the epoxy resin pieces of the reinforcing plate adhere to the connector connecting portion.

FIG. 7 is a top view of a configuration in which a plating lead is obliquely extended from a terminal portion of a circuit metal foil in a connector connection portion of a conventional FPC. As shown in the figure, when the plating lead 21a is obliquely extended from the terminal portion of the circuit metal foil 12 of the connector connecting portion 15 and the connector connecting portion 15 of the FPC 14 is inserted into the connector side (not shown), the plating lead 21a is It will not hit the connector connector (not shown). Accordingly, since the plating lead 21 is not peeled off, there is no possibility that the tip portion of the circuit metal foil 12 is peeled off from the insulating base (not shown).
Japanese Utility Model Publication No. 55-173174

  However, in recent years, the circuit configuration of FPC has been increased in density, and accordingly, the connector connection portions have been miniaturized, and the intervals between the terminals of the connector connection portions have become extremely narrow, so considerable accuracy is required. Become. Therefore, as in the technique disclosed in Patent Document 1, the method of forming the taper at the tip portion of the connector connection portion by cutting the tip portion of the connector connection portion by polishing or the like corresponds to the miniaturization of the connector connection portion. I can't. In addition, it takes considerable man-hours to finely process the tip of the connector connecting portion by polishing or the like, and it cannot be used for mass production of FPC.

  In addition, as shown in FIG. 7, when the plating lead 21 a extends obliquely from the terminal portion of the circuit metal foil 12 of the connector connection portion 15, the terminal spacing of the circuit metal foil 12 is reduced by increasing the density of the FPC 14. When this is done, a connector connector (not shown) that contacts the terminal portion of the adjacent circuit metal foil 12 comes into contact with the adjacent plating lead 21a and the plating lead 21a is peeled off, so that the adjacent circuit metal foil 12 is removed. There is a risk of short-circuiting each other.

  Therefore, contact failure due to glass fiber burrs or the like from the reinforcing plate to be bonded to the connector connecting portion is prevented, and when inserted into the connector, the circuit metal foil is caused by sliding between the connector connecting portion of the FPC and the connector contact. The technical problem which should be solved in order to eliminate the peeling defect of a problem arises, and this invention aims at solving this problem.

The present invention has been proposed to achieve the above object, and the invention according to claim 1 is a flexible circuit board having a reinforcing plate in a connector connecting portion.
A tip portion of the connector connecting portion is formed with an eave portion having a shape covering an end portion of the reinforcing plate, and the eave portion is bent toward the reinforcing plate .

  According to this configuration, since the eaves portion having a shape that covers the end portion of the reinforcing plate is formed at the distal end portion of the connector connection portion, the reinforcement is provided when the connector connection portion of the flexible circuit board is inserted into the connector. Glass fiber burrs and epoxy resin pieces on the plate are difficult to peel off. As a result, there is no possibility that glass fiber burrs or epoxy resin pieces enter the terminal portion of the connector connecting portion and cause insulation failure.

  In the invention according to claim 2, the connector connecting portion is formed by patterning a circuit metal foil on the surface of the insulating base, and the insulating base and the circuit metal foil are integrally formed at the tip portion of the connector connecting portion. 2. A flexible circuit board according to claim 1, wherein an eaves portion is formed.

  According to this configuration, when the connector connecting portion of the flexible circuit board is inserted into the connector, the connector connector does not hit the tip of the circuit metal foil formed on the connector connecting portion, so the circuit metal foil is insulated from the base. There is no risk of peeling off.

  The invention according to claim 3 is characterized in that the reinforcing plate is bonded to the back surface of the insulating base via an adhesive, and the adhesive protrudes from the end of the reinforcing plate. Providing a substrate.

  According to this configuration, when the reinforcing plate is bonded to the back surface of the insulating base and bonded, the adhesive protrudes from the end of the reinforcing plate. Glue the resin pieces. As a result, the glass fiber burrs and epoxy resin pieces of the reinforcing plate are more difficult to peel off, and there is almost no possibility that the glass fiber burrs and epoxy resin pieces enter the terminal portions of the connector connecting portion and cause insulation failure.

  In the invention according to claim 4, the eaves portion of the connector connecting portion is formed only in the region where the terminal of the connector connecting portion exists, and the reinforcing plate is provided to the tip portion in both side regions where the terminal of the connector connecting portion does not exist. The flexible circuit board according to claim 1, 2 or 3 is provided.

  According to this configuration, since the eaves portion is formed only in the region where the terminal of the connector connection portion exists, the connector connector does not hit the tip of the circuit metal foil when the connector connection portion is inserted into the connector. Therefore, there is no possibility that the circuit metal foil is peeled off from the insulating base. Furthermore, since the reinforcing plates are present up to the tip in both side regions of the connector connecting portion where no terminal exists, the connector connecting portion can be reinforced more firmly.

Further, the invention according to claim 5 is a method of manufacturing a flexible circuit board having a reinforcing plate in a connector connection portion, a first step of measuring a product outer shape in a work of the flexible circuit board,
A second step of punching out the portion of the reinforcing plate corresponding to the region where the terminal exists at the tip of the connector connecting portion;
A third step of attaching the reinforcing plate larger than the product outer shape in the workpiece of the flexible circuit board;
Flexible circuit board, characterized in that unplug beats dimensioned been PACKAGE In the first step, the tip portions of the connector connecting portion at that time and a fourth step of forming a visor portion Te sags The manufacturing method of this is provided.

  According to such a method of manufacturing a flexible circuit board, the flexible circuit board can be manufactured by a small number of work steps, and the shape of the end portion of the reinforcing plate is covered with the tip end portion of the connector connection portion in the process. An eaves part can be formed. Thereby, when the connector connecting portion of the flexible circuit board is inserted into the connector, the glass fiber burrs and the epoxy resin pieces of the reinforcing plate are hardly peeled off. As a result, there is no possibility that glass fiber burrs or epoxy resin pieces enter the terminal portion of the connector connecting portion and cause insulation failure.

  The invention according to claim 6 is characterized in that the punched portion of the reinforcing plate punched in the second step is a portion cut out by 0.2 to 1.0 mm from the tip of the outer shape of the product. A method for producing a flexible circuit board according to claim 5 is provided.

  According to such a method for manufacturing a flexible circuit board, the eaves portion formed at the distal end portion of the connector connecting portion can be made to have an optimal bent dimension, and the mechanical strength of the distal end portion is prevented from deteriorating. be able to.

  According to the first aspect of the present invention, since the eaves portion having a shape covering the reinforcing plate is formed at the distal end portion of the connector connecting portion, the glass fiber burrs of the reinforcing plate are inserted when the connector connecting portion is inserted into the connector. And the epoxy resin piece is difficult to peel off, and there is no possibility that the burr or the epoxy resin piece enters the terminal portion of the connector connecting portion and causes an insulation failure.

  According to the invention described in claim 2, when the connector connecting portion is inserted into the connector, the connector connector does not hit the tip of the circuit metal foil of the connector connecting portion. Further, there is no possibility that the circuit metal foil is peeled off from the insulating base.

  According to invention of Claim 3, since the adhesive agent which adhere | attaches a reinforcement board protrudes to the edge part of this reinforcement board, since the burr | flash and epoxy resin piece of the glass fiber of a reinforcement board become difficult to peel further, Claims In addition to the effects described in 1 and 2, there is almost no risk of glass fiber burrs or epoxy resin pieces entering the terminal portion of the connector connecting portion.

  According to the invention described in claim 4, since the eaves portion is formed only in the region where the terminal of the connector connecting portion exists, in addition to the effects of claims 1, 2, and 3, the circuit metal foil is insulated base. Therefore, the connector connection portion can be reinforced more firmly.

  According to the invention described in claim 5, the flexible circuit board can be manufactured with a small number of work steps, and in the step, the eaves portion shaped so as to cover the end portion of the reinforcing plate is provided at the tip end portion of the connector connection portion. Can be formed. Thus, a highly reliable flexible circuit board that does not cause an insulation failure in the terminal portion of the connector connecting portion can be manufactured at low cost.

  According to the sixth aspect of the present invention, the eaves portion formed at the tip portion of the connector connecting portion can have an optimum bent dimension, and the mechanical strength of the tip portion can be prevented from deteriorating. .

  The present invention prevents a contact failure due to glass fiber burrs or the like from a reinforcing plate to be bonded to a connector connecting portion, and a circuit by sliding between a connector connecting portion of an FPC and a connector contact when inserted into a connector. In order to achieve the purpose of eliminating the problem of peeling off the metal foil, a flexible circuit board having a reinforcing plate at the connector connecting portion is formed with an eave portion having a shape covering the end of the reinforcing plate at the tip of the connector connecting portion. Realized by providing a flexible circuit board.

  Hereinafter, a preferred embodiment of the connector connecting portion in the FPC of the present invention will be described in detail with reference to FIGS. FIG. 1 is a cross-sectional view of a connector connecting portion in an FPC according to an embodiment of the present invention. As shown in the figure, the surface of the circuit metal foil 2 patterned on the insulating base 1 is coated with a cover film 3 to form an FPC 4, and the front side of the connector connecting portion 5 at the tip of the FPC 4 is the circuit metal foil. Nickel / gold plating 6 is applied to the surface 2, and a reinforcing plate 8 is bonded to the back side of the connector connecting portion 5 with an adhesive 7.

  As shown in FIG. 1, the insulating base 1, the circuit metal foil 2, and the nickel / gold plating 6 existing at the tip of the connector connecting portion 5 are integrated and bent toward the reinforcing plate 8 to form an eave portion 5a. ing. That is, the connector connecting portion 5 of the FPC 4 has a tip portion bent to the reinforcing plate 8 side to form an eave portion 5a, and the reinforcing plate 8 exists on the back side from the base portion of the eave portion 5a.

  With such a configuration, when the connector connecting portion 5 of the FPC 4 is inserted into a connector (not shown), the eaves portion 5a at the distal end portion of the connector connecting portion 5 is an eave that covers the reinforcing plate 8. It is possible to prevent the glass fiber burrs, epoxy resin pieces, and the like of the plate 8 from being peeled off, and to prevent the glass fiber burrs, epoxy resin pieces, etc. from wrapping around the surface of the connector connecting portion 5. Further, when the adhesive 7 for adhering the reinforcing plate 8 protrudes from the reinforcing plate 8 and is bonded, the adhesive 7 protruding from the reinforcing plate 8 also bonds glass fiber burrs, epoxy resin pieces, etc. Glass fiber burrs and epoxy resin pieces are more difficult to peel off.

  Further, by providing a structure in which the eaves portion 5a is provided at the distal end portion of the connector connecting portion 5, when the connector connecting portion 5 of the FPC 4 is inserted into a connector (not shown), a connector connector (not shown) is connected to the connector connecting portion. 5, the circuit metal foil 2 is not peeled off from the insulating base 1.

The structure in which the tip end portion (eave portion 5a) of the connector connecting portion 5 as shown in FIG. That is, as shown in the top view of the connector connecting portion in the FPC according to one embodiment of the present invention shown in FIG. 8 may be cut out, and both end portions outside the broken line region may be bonded so that the reinforcing plate 8 exists up to the final end. By doing in this way, reinforcement of the connector connection part 5 by the reinforcement board 8 can be strengthened more.

  FIG. 3 is a diagram showing a manufacturing process of the connector connecting portion in the FPC according to one embodiment of the present invention. First, in the product outline dimensioning step shown in FIG. 3A, the product outline of the FPC 4 is dimensioned inside the FPC workpiece 10. Next, in the reinforcing plate laminating step shown in FIG. 3 (b), the reinforcing plate 8 previously punched and formed larger than the product outer shape of the FPC 4 is placed inside the FPC work 10 via an adhesive sheet (not shown). to paste together. At this time, the reinforcing plate front end region 8a corresponding to the location where the terminal of the connector connecting portion exists is punched out in advance.

Then, the product contour punching step shown in FIG. 3 (c), the punched product outline of FPC4 was dimensioned in FIG. 3 (a), the punching portion 4a is Te sag in the thickness direction of the FPC4 as represented by hatching Thus, the connector connecting portion 5 (see FIGS. 1 and 2) having the structure in which the eaves portion 5a as shown in FIG. 1 is formed is obtained.

  At this time, the punching dimension of the reinforcing plate front end region 8a in the reinforcing plate 8 is 0.2 to 1.0 mm inward from the front end of the product outer shape of the FPC 4, and preferably 0 inward from the front end of the product outer shape of the FPC 4. It is desirable to cut out about 5mm. If this punching dimension is shorter than that, a desired bent shape cannot be obtained at the tip of the connector connecting portion 5. Moreover, since the mechanical strength of the front-end | tip part in the connector connection part 5 will fall when a punching dimension is longer than it, it is unpreferable.

 The present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

Sectional drawing of the connector connection part in FPC which concerns on one Example of this invention. The top view of the connector connection part in FPC which concerns on one Example of this invention. The figure which shows the manufacturing process of the connector connection part in FPC which concerns on one Example of this invention. Sectional drawing of the connector connection part in the conventional FPC. The top view of the connector connection part in the conventional FPC. Sectional drawing when the connector connection part in the conventional FPC is inserted in the connector. The top view of the structure which extended the plating lead diagonally from the terminal part of the circuit metal foil in the connector connection part of the conventional FPC.

Explanation of symbols

1, 11 Insulation base 2, 12 Circuit metal foil 3, 13 Cover film 4, 14 FPC
4a Punched place 5, 15 Connector connection portion 5a Eave portion 6, 16 Nickel / gold plating 7, 17 Adhesive 8, 18 Reinforcement plate 8a Reinforcement plate tip region 10 FPC work 19 Glass fiber burr 20 Epoxy resin piece 21, 21a Plating lead 22 Connector connector

Claims (6)

In a flexible circuit board having a reinforcing plate in the connector connection part,
A flexible circuit board, wherein a tip portion of the connector connecting portion is formed with an eave portion having a shape covering an end portion of the reinforcing plate, and the eave portion is bent toward the reinforcing plate . The connector connecting portion is formed by patterning a circuit metal foil on the surface of the insulating base,
2. The flexible circuit board according to claim 1, wherein a tip portion of the connector connecting portion forms the eaves portion integrally with the insulating base and the circuit metal foil.   The flexible circuit board according to claim 2, wherein the reinforcing plate is bonded to the back surface of the insulating base via an adhesive, and the adhesive protrudes from an end of the reinforcing plate.   The eaves portion of the connector connecting portion is formed only in a region where the terminal of the connector connecting portion exists, and both side regions where the terminal of the connector connecting portion does not exist are provided with the reinforcing plate up to the tip portion. The flexible circuit board according to claim 1, 2 or 3. In the manufacturing method of a flexible circuit board having a reinforcing plate in the connector connection portion, a first step of measuring the product outer shape in the workpiece of the flexible circuit board;
A second step of punching out the portion of the reinforcing plate corresponding to the region where the terminal exists at the tip of the connector connecting portion;
A third step of attaching the reinforcing plate larger than the product outer shape in the workpiece of the flexible circuit board;
Flexible circuit board, characterized in that unplug beats dimensioned been PACKAGE In the first step, the tip portions of the connector connecting portion at that time and a fourth step of forming a visor portion Te sags Manufacturing method. 6. The flexible circuit board according to claim 5, wherein a punching portion of the reinforcing plate punched in the second step is a portion cut out by 0.2 to 1.0 mm from a tip portion of the outer shape of the product. Production method.

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