JP2010226006A - Method of manufacturing flexible circuit sheet junction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide techniques for obtaining a large number of flexible circuit sheets from an original material to overcome disadvantages in the conventional art in which diversified shapes of flexible circuit sheets, which are rarely rectangular or square, make it difficult to obtain a large number of flexible circuit sheets from an original material. <P>SOLUTION: A plurality of first flexible circuit sheets 2 are cut out from an original material 1 where the first flexible circuit sheets 2 of a nearly rectangular shape are formed to be parallel to each other. A plurality of second flexible circuit sheets 3 are cut out from the original material 1 where the second flexible circuit sheets 3 of a cranked shape are formed to be parallel to each other. The cut-out second flexible circuit sheets 3 are partially overlapped with the cut-out first flexible circuit sheets 2, and first contact terminals 23a, 23b formed on the first flexible circuit sheets 2 in the overlapped portions are made to electrically contact with second contact terminals 34a, 35a formed on the second flexible circuit sheets 3 in those portions, so that the first flexible circuit sheets 2 and the second flexible circuit sheets 3 are joined together. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a flexible circuit sheet assembly.

  A flexible circuit sheet called a so-called FPC (Flexible Printed Circuit) is widely used, and for example, as disclosed in Patent Document 1, it is also used for a backlight of a liquid crystal display. In general, the flexible circuit sheet has a shape corresponding to the internal structure of the device using the flexible circuit sheet. That is, the shape of the flexible circuit sheet is rarely rectangular or square, and is often irregular.

  On the other hand, when the flexible circuit sheet is small, a plurality of flexible circuit sheets are prepared from a large original sheet. That is, a plurality of flexible circuit sheets having the same shape are formed on one original fabric, and the plurality of flexible circuit sheets are cut out from the one original fabric.

JP 2003-179322 A

However, if the flexible circuit sheet has an irregular shape, many flexible circuit sheets cannot be obtained from a single sheet.
Therefore, the problem to be solved by the present invention is to make it possible to obtain many flexible circuit sheets from a single sheet.

In order to solve the above problems, according to the first aspect of the present invention,
Cutting out the first flexible circuit sheet from an original fabric formed such that a plurality of first flexible circuit sheets having a substantially quadrangular shape are parallel to each other;
The second flexible circuit sheet is cut out from a raw material formed such that a plurality of second flexible circuit sheets having different shapes from the first flexible circuit sheet are parallel to each other,
The first flexible circuit sheet is formed by partially overlapping the cut second flexible circuit sheet on the cut first flexible circuit sheet, and the overlapped portion is formed on the first flexible circuit sheet. And taking electrical contact with the second contact terminal formed on the second flexible circuit sheet, and joining the first flexible circuit sheet and the second flexible circuit sheet. A method of manufacturing a flexible circuit sheet assembly is provided.

Preferably, the plurality of first flexible circuit sheets are formed on the original fabric with both short sides thereof aligned.
Preferably, the plurality of second flexible circuit sheets are formed on the original fabric with both ends thereof aligned.
Preferably, the second flexible circuit sheet is aligned with one long side of the cut first flexible circuit sheet while the one end of the cut second flexible circuit sheet is aligned with the first flexible circuit sheet. The first flexible circuit sheet and the second flexible circuit sheet are partially overlapped so as to extend from the other long side of the circuit sheet.

  According to the present invention, a large number of flexible circuit assemblies can be produced from a single sheet.

It is a top view of the original fabric in the embodiment of the present invention. It is a top view of the 1st flexible circuit sheet in the embodiment. It is a top view of the 2nd flexible circuit sheet in the embodiment. It is a top view of the flexible circuit sheet assembly in the same embodiment. It is a front view of the backlight module using the flexible circuit sheet assembly in the embodiment. It is a top view of the original fabric in a comparative example.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

  FIG. 1 is a view showing an original fabric 1. The original fabric 1 is a flexible sheet provided in a substantially quadrilateral shape. In the original fabric 1, 12 flexible circuit sheets 2 having a quadrilateral shape are supported by a sheet-like outer frame 4, and 14 flexible circuit sheets 3 are supported by the outer frame 4. .

  These flexible circuit sheets 2 have a substantially quadrangular shape, in particular, a rectangular shape. These flexible circuit sheets 2 have the same shape. The long sides of the flexible circuit sheets 2 are parallel to each other, the flexible circuit sheets 2 are arranged in a row in the long side direction of the original fabric 1, and the short sides of the flexible circuit sheets 2 are mutually aligned. It's all there. The long sides of the flexible circuit sheet 2 are parallel to the short side of the original fabric 1, and the short sides of the flexible circuit sheet 2 are parallel to the long side of the original fabric 1.

  A cut 29 is formed so as to surround the flexible circuit sheet 2, and the flexible circuit sheet 2 and the outer frame 4 are separated by the cut 29. The bridging portion 28 is connected to a part of the peripheral edge of the flexible circuit sheet 2, the bridging portion 28 is connected to the outer frame 4, and the flexible circuit sheet 2 is supported by the outer frame 4 by the bridging portion 28. . If the bridging portion 28 is cut, the flexible circuit sheet 2 can be removed from the outer frame 4.

  A wiring pattern 23 is formed on the flexible circuit sheet 2. Specifically, as shown in FIG. 2, the flexible circuit sheet 2 is a cover sheet made of insulating resin (for example, made of polyimide) on a sheet-like base material 21 made of insulating resin (for example, made of polyimide). 22 (in FIG. 2, the hatched area) is joined, and the wiring pattern 23 is patterned between the sheet-like base material 21 and the cover sheet 22. Further, there is a portion 24 where the cover sheet 22 is not overlapped on a part of the sheet-like base material 21, and a part of the wiring pattern 23 is exposed as the contact terminals 23 a and 23 b in the portion 24. The width (the length in the direction along the long side of the flexible circuit sheet 2) of the portion 24 where the cover sheet 22 does not overlap the part of the sheet-like base material 21 is the length of the flexible circuit sheet 3 to be described later. Equal to width.

  Further, LEDs are mounted on the portion 25 shown in FIG. 2, and the LEDs are connected to the wiring pattern 23 in the portion 25. A protection circuit component is mounted on the portion 26 shown in FIG. 2, and the protection circuit component is connected to the wiring pattern 23 in the portion 26.

  As shown in FIG. 1, the 14 flexible circuit sheets 3 form a crank shape, and these flexible circuit sheets 3 all have the same shape. These flexible circuit sheets 3 are arranged in two rows in the short-side direction of the original fabric 1, and both ends of these flexible circuit sheets 3 are aligned with each other.

  A cut 39 is formed so as to surround the flexible circuit sheet 3, and the flexible circuit sheet 3 and the outer frame 4 are separated by the cut 39. A bridging portion 38 is connected to a part of the periphery of the flexible circuit sheet 3, the bridging portion 38 is connected to the outer frame 4, and the flexible circuit sheet 3 is supported by the outer frame 4 by the bridging portion 38. . If the bridge portion 38 is cut, the flexible circuit sheet 3 can be removed from the outer frame 4.

  Two wires 34 and 35 are formed from one end portion of the flexible circuit sheet 3 to the other end portion. Specifically, as shown in FIG. 3, the flexible circuit sheet 3 is a cover sheet made of insulating resin (for example, made of polyimide) on a sheet-like base material 31 made of insulating resin (for example, made of polyimide). 32 (in FIG. 3, the hatched area) is joined, and wirings 34 and 35 are patterned between the sheet-like base material 31 and the cover sheet 32. At one end portion of the flexible circuit sheet 3, there is a portion 36 where the sheet-like base material 31 does not overlap the cover sheet 32, and at that portion 36, one end portions of the wirings 34 and 35 are exposed as contact terminals 34 a and 35 a. ing. At the other end portion of the flexible circuit sheet 3, there is a portion 37 where the cover sheet 32 does not overlap the sheet-like base material 31, and at the portion 37, the other end portions of the wires 34 and 35 are exposed as terminals 34b and 35b. is doing.

A method of manufacturing the flexible circuit sheet assembly 10 shown in FIG. 4 from the original fabric 1 shown in FIG. 1 will be described.
First, the bridging portion 28 is cut, and the flexible circuit sheet 2 is extracted from the outer frame 4. Further, the bridging portion 38 is cut and the flexible circuit sheet 3 is extracted from the outer frame 4.

  Next, the flexible circuit sheet 3 is joined to the flexible circuit sheet 2. Specifically, the portion 36 of the cover sheet 32 where the sheet-like base material 31 is not overlapped is overlapped with the portion 24 of the sheet-like base material 21 of the flexible circuit sheet 2 where the cover sheet 22 is not overlapped. The portions 24 and 36 are joined together. When the portion to be joined 36 is overlapped with the portion to be joined 24, the side 3 a at one end of the flexible circuit sheet 3 is aligned with the long side 2 a of the flexible circuit sheet 2, and the flexible circuit sheet 3 can be placed. The flexible circuit sheets 2 and 3 are aligned so as to extend from the other long side 2 b of the flexible circuit sheet 2. In joining, the contact terminal 23a and the contact terminal 34a are brought into electrical contact, and the contact terminal 23b and the contact terminal 35a are brought into electrical contact.

As a joining method, there are a method using an anisotropic conductive film, a method using solder, a method using an interconnector, and the like.
When an anisotropic conductive film or interconnector is used, the anisotropic conductive film or interconnector is sandwiched between the bonded portion 24 of the flexible circuit sheet 2 and the bonded portion 36 of the flexible circuit sheet 3. The part is thermocompression bonded. Thereby, the to-be-joined part 24 of the flexible circuit sheet 2 and the to-be-joined part 36 of the flexible circuit sheet 3 are adhere | attached by an anisotropic conductive film or an interconnector. The conductive fine particles contained in the anisotropic conductive film can conduct the contact terminals 23a and 34a, and can conduct the contact terminals 23b and 35a.

  When solder is used, solder is applied to both or one of the contact terminals 23a and 34a, and solder is applied to both or one of the contact terminals 23b and 35a. The joined portion 24 of the flexible circuit sheet 2 and the joined portion 36 of the flexible circuit sheet 3 are overlapped, the contact terminal 23a and the contact terminal 34a are overlapped, and the contact terminal 23b and the contact terminal 35a are overlapped. The solder between the contact terminal 23a and the contact terminal 34a and the solder between the contact terminal 23b and the contact terminal 35a are reflowed, and the contact terminal 23a and the contact terminal 34a are soldered together, and the contact terminal 23b and the contact terminal 35a are soldered. Join.

  Thus, the flexible circuit sheet assembly 10 shown in FIG. 4 is completed. The flexible circuit sheet assembly 10 has a shape in which a crank-shaped belt-like portion (flexible circuit sheet 3) extends from one long side 2b of a substantially quadrangular portion (flexible circuit sheet 2). Yes. Thus, as shown in FIG. 4, the LED 41 is mounted on each portion 25.

  This flexible circuit sheet assembly 10 is used for a backlight of a liquid crystal display. FIG. 5 is a front view of the backlight module. The backlight module includes a unit 11 formed by laminating a light guide plate and a light diffusing plate, and a flexible circuit sheet 2 is provided along one side surface (incident surface) of the light guide plate. The LED 41 mounted thereon is covered with the light shielding portion 12. When power is supplied from the terminals 34b and 35b to the LED, the LED emits light. The light emitted from the LED is incident on one side of the light guide plate, reflected by the back surface (reflecting surface) of the light guide plate, and diffused and emitted from the light diffusion plate arranged on the front surface side (output surface) of the light guide plate. To do.

  As described above, according to the present embodiment, since the flexible circuit sheet 2 has a substantially quadrangular shape, many flexible circuit sheets 2 can be arranged in a narrow region. In particular, as shown in FIG. 1, a plurality of flexible circuit sheets 2 are parallel to each other, one short side of these flexible circuit sheets 2 is aligned with each other, and the other short sides are also aligned with each other. Therefore, many flexible circuit sheets 2 can be arranged in a narrow region. Similarly, the flexible circuit sheet 3 is provided in a crank shape, and the flexible circuit sheets 3 are parallel to each other with both ends thereof aligned, so that many The flexible circuit sheet 3 can be arranged in a narrow area. Then, since the odd-shaped flexible circuit sheet assembly 10 is manufactured from the substantially quadrilateral flexible circuit sheet 2 and the crank-shaped flexible circuit sheet 3, the flexible circuit sheet assembly 10 per one flexible circuit sheet assembly 10 is manufactured. The required area of the original fabric 1 can be reduced. That is, as shown in the comparative example of FIG. 6, when the flexible circuit sheet 110 having the same shape as the flexible circuit sheet assembly 10 is arranged on the original fabric 101 having the same area as the original fabric 1, 1 Although only 10 flexible circuit sheets 110 can be obtained from one sheet of original fabric 101, in this embodiment, as shown in FIG. 1 and FIG. The flexible circuit sheet assembly 10 can be obtained. Therefore, according to this embodiment, since more flexible circuit sheet assemblies 10 can be obtained from one original fabric 1, costs can be reduced.

  In addition, since the flexible circuit sheet 2 and the flexible circuit sheet 3 have a simple shape, defects such as folds and wrinkles that occur when the flexible circuit sheet 2 and the flexible circuit sheet 3 are handled. Can be suppressed.

In the above embodiment, the backlight of the liquid crystal display is given as an application of the flexible circuit sheet assembly 10, but it may be used for other applications.
In the above embodiment, both the plurality of flexible circuit sheets 2 and the plurality of flexible circuit sheets 3 are formed on one original fabric 1, but the plurality of flexible circuit sheets 2 are formed. The original fabric on which the plurality of flexible circuit sheets 3 are formed may be separate. Further, the number of flexible circuit sheets 2 and 3 formed per sheet is not limited to the above embodiment, and may be two or more.

DESCRIPTION OF SYMBOLS 1 Original fabric 2 Flexible circuit sheet (1st flexible circuit sheet)
3 Flexible circuit sheet (second flexible circuit sheet)
10. Flexible circuit sheet assembly 23a, 23b Contact terminal (first contact terminal)
24, 36 Joined part 34a, 35a Contact terminal (second contact terminal)

Claims (4)

Cutting out the first flexible circuit sheet from an original fabric formed such that a plurality of first flexible circuit sheets having a substantially quadrangular shape are parallel to each other;
The second flexible circuit sheet is cut out from a raw material formed such that a plurality of second flexible circuit sheets having different shapes from the first flexible circuit sheet are parallel to each other,
The first flexible circuit sheet is formed by partially overlapping the cut second flexible circuit sheet on the cut first flexible circuit sheet, and the overlapped portion is formed on the first flexible circuit sheet. And taking electrical contact with the second contact terminal formed on the second flexible circuit sheet, and joining the first flexible circuit sheet and the second flexible circuit sheet. A method for producing a flexible circuit sheet assembly, comprising:   2. The method for manufacturing a flexible circuit sheet assembly according to claim 1, wherein the plurality of first flexible circuit sheets are formed on the original fabric with both short sides thereof aligned.   3. The method for manufacturing a flexible circuit sheet assembly according to claim 1, wherein the plurality of second flexible circuit sheets are formed on the original fabric in a state where both ends thereof are aligned. .   The second flexible circuit sheet is aligned with one long side of the cut first flexible circuit sheet while the one end of the cut second flexible circuit sheet is aligned with the long side of the first flexible circuit sheet. 4. The movable body according to claim 1, wherein the first flexible circuit sheet and the second flexible circuit sheet are partially overlapped so as to extend from another long side. Manufacturing method of flexible circuit sheet assembly.

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