JPS59219980A - Method of bending flexible printed board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for bending a flexible printed board.

In recent years, so-called flexible printed boards (hereinafter abbreviated as FPC), in which conductor circuits are printed on the surface of a base film made of polyester or polyimide, have been widely used. There may be cases where it is necessary to bend the material. For example, when performing a bending process as shown in Figure 1, the FP
Bend the end of CI to form a bent part 1a, insert a reinforcing plate 2 inside this bent part 1a, and glue the inner surface lc of the bent part 1a on both sides of this reinforcing plate 2 with adhesive 8. The bent state is maintained by gluing.

By the way, F'PCI generally has a strong repulsive force against bending, and in particular, double-sided FPCs with circuits formed on both sides will peel off within a short period of time when bonded with a room temperature pressure type adhesive. . For this reason, bonding is performed by applying pressure and heating using a thermal crosslinking type adhesive. However, such bonding methods not only require a hot plate press at high temperature and high pressure, but also have the disadvantage that the crosslinking process is long, resulting in poor productivity and high costs.

In view of the above-mentioned circumstances, this invention is an FPC that can bend an FPC in a short time using extremely simple processing equipment.
This provides a method for bending a PC.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 is a cross-sectional view for explaining one embodiment of the present invention. In the figure, parts corresponding to those in FIG.

In this figure, the wound is a heater. This heating i4 consists of a prismatic heating body 4a, a heater 3b built into the heating body 4a, and a heat insulating material 4c on three sides eM of the heating body 4a. The heating element 4a has a lacrimality on the bale surface of 300°C to 3.
It is kept at 50°C.
4. Li” due to such heater scratches.
The following procedure is used to bend the PCI.

■ Bend the FPCI with a suitable presser foot f5 and press the bent part 1a.
The inner surface IC and the reinforcing plate 2 are pressed and bonded together with an adhesive 8.

■Next, as shown in Figure @2, the heating body 4 of the heater 4 is attached to the curved surface 1d of the bent portion 1a. Apply pressure by pressing a for about 30 minutes. Heat for 40 seconds.

Through such processing, the curved surface 1d of the bent portion 1a is heated and deformed, and the repulsive force is eliminated. As a result, the inner surface IC of the bent portion 1a and the reinforcing plate 2 do not separate, and
The bent portion la does not deform over a long period of time.

As explained above, this invention has the advantage that the bent portion can be formed in a short time because the bent portion is locally heated to a high temperature to give permanent deformation to the bent portion. It will be done. Furthermore, since expensive equipment is not required, processing costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 shows an example of a bent FPC. The perspective view and Figure @2 are cross-sectional views for explaining one embodiment of the present invention. l...FPC (flexible print i), l
a...Bent part, 2...Reinforcement plate, 8.
...adhesive, scratches ...heater, etc.
・Temporary presser foot. Applicant: Fujikura Electric Wire Co., Ltd.

Claims (1)

[Claims] When the flexible printed board is bent, a reinforcing plate is inserted into the bent part and both are bonded with adhesive, and then the bent part is heated with a heater from the outside to give permanent deformation. A method for bending flexible printed boards.