JPS6010689A - Method of producing flexible circuit 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 manufacturing a flexible circuit board that can manufacture lexical circuit boards at a high yield.

Depending on the type of flexible circuit board, there are those that require finer conductor patterns and higher density, as well as flexibility, and in such flexible circuit boards, the conductive foil and base material must be as thin as possible. It is necessary to use materials to increase flexibility as much as possible. However, such highly flexible flexible circuit boards tend to cause wrinkles or creases during the manufacturing process, which tends to reduce product yields, so they must be handled carefully in each process. There are various difficulties in terms of workability, such as the need to

Therefore, the present invention provides a method for manufacturing a high-yield, high-quality flexible circuit board by handling it in a state in which flexibility can be relatively suppressed during manufacturing, and for this purpose, According to the present invention, a required circuit pattern is formed on a flexible base material so as to provide a plurality of flexible circuit board regions, and the circuit pattern is applied to the remaining flexible base material portion excluding each flexible circuit board region. A reinforcing layer is formed to suppress the flexibility of the base material, and each flexible circuit board area is punched out in the final process.

A reinforcing layer and a curable resin material are applied to the top or back side of the flexible substrate by screen printing means, or a sheet material is used to cover the non-flexible portion of each flexible circuit board area. It is possible to employ the left method to bond to the back side of the flexible substrate as shown in FIG.

The drawings conceptually illustrate embodiments of the present invention, and include FIG. 1 and FIG. In the figure, / is a film-like flexible base material, and a large number of flexible circuit board areas 2 each having a required circuit pattern 3 are formed on this base material l, and B is a product of these areas. These are unnecessary conductive foil parts such as copper foil left in the external line and the non-circuit board area. The circuit pattern 3 and the unnecessary conductive foil portion 7 of each flexible circuit board area can be formed as appropriate by etching means, even a flexible copper-clad laminate, for example. Each circuit board area 2 has a flexible portion≠ and a non-flexible portion where a connecting terminal portion is to be formed at the end of the flexible portion! It can be arbitrarily configured to have In the present invention, as shown in 1 of FIG. 2, at the stage where each circuit pattern 3 is subjected to the necessary plating treatment, etc., a reinforcing layer g or 9, and thereby the subsequent steps are to be carried out in a state in which the flexibility of the flexible base material 1 is suppressed as much as possible. The reinforcing layer r, 9 layers of curable material 1, such as epoxy resin, can be formed continuously by screen printing means, etc., and these can be applied to the entire flexible substrate having a large number of flexible circuit board areas 2. Since it acts in a direction that can increase the rigidity of the material, it is designed to be made as close as possible to something that is easy to handle, such as a rigid circuit board. Therefore, by providing such a reinforcing layer or warp, each flexible circuit board area, 211-1',
It is possible to smoothly process subsequent steps without causing wrinkles or bends, maintains high dimensional stability, and has good workability without having to be extremely careful in handling. This is extremely advantageous in terms of efficiency.

Then, in the final step, by punching along the product outline B, it becomes possible to easily obtain a high-yield, high-quality flexible circuit board.

In addition to the structure described above, the structure of the reinforcing layer is also suitable as shown in FIG. 3 and FIG. A sheet material 10 made of tape-shaped paper or film material is attached to the lower part of the non-flexible part 3 of 2 using an adhesive IOA.
Or, as illustrated on the left side, a single sheet material /I is attached to the back side of the base material / belonging to those non-flexible parts with an adhesive / /A. It is also possible to configure it as follows. According to such a structure of the reinforcing layer, in addition to the same flexibility suppressing function as described above, the portions of the base material l belonging to the non-flexible portions j of each fleximole circuit board area are subjected to a punching process and the sheet materials 10 are Since it is possible to obtain a product in which the or// is simultaneously punched and joined, it is possible to suitably meet the need for, for example, appropriately reinforcing the terminal portion of a flexible circuit board.

When a flexible circuit board that requires particular flexibility is required, the base material used for it, such as a copper-clad laminate, is also quite thin, so when manufacturing such a product, is provided on the top or back surface of the base material 1 covered with conductive foil so as to exclude each circuit board area before forming the reinforcing layer 9, 10 or 1/equal circuit pattern 3. It is preferable that the flexibility of the base material 1 to be used from the first stage of the process is suppressed as much as possible before it is subjected to the subsequent circuit pattern forming process, plating process, etc.

In addition, in such a case, if necessary, a sheet material 10 as shown in FIGS. , on the contrary, sheet material 10. , l/ are first applied to the base material l, and then a reinforcing groove 9 is further formed thereon, so as to suppress the overall flexibility of the base material l.

Which of these forms to adopt can be determined arbitrarily after comprehensively considering the shape of each flexible circuit board to be a product, the circuit pattern density, the size of the flexible portion t, its shape, etc. You can decide. In any case, in the case of the present invention, a reinforcing layer is provided on the base material l to suitably suppress its flexibility, thereby improving handleability in the manufacturing process and preventing product wrinkles, bends, etc. It is possible to employ various changes or replacement means without departing from the gist of the present invention.

According to the present invention, as is clear from the above description, problems such as ease of handling and wrinkles or bending during the production of flexible circuit boards that particularly require flexibility can be solved by the simple means of forming a reinforcing layer. Since it can be resolved,
It has the advantage of being able to manufacture high-quality products with excellent dimensional stability and high yields with high efficiency.

[Brief explanation of the drawing]

1 and 1 are conceptual partial plan views and cross-sectional views for explaining one embodiment of the flexible circuit board manufacturing method of the present invention, and FIGS. 3 and 11 are similarly other embodiments. FIG. 1 is a plan view and a sectional view of part 1 according to FIG. l. 0. Flexible base material 00.7 Circuit board area 3 009 Circuit pattern... Possible Flexible part j 61. Non-flexible part B...Product outline line 7 00. Unnecessary conductive foil portions g, q, , Reinforcement layer io, ti, Reinforcement sheet material 10A, //A, Adhesion Applicant: Nippon Mektron Co., Ltd.

Claims (3)

[Claims] (1) Before and after forming a required circuit pattern so as to provide a plurality of flexible circuit board areas on a flexible base material, the remaining part of the flexible base material excluding the flexible circuit board area is A method for manufacturing a flexible circuit board, characterized by forming a reinforcing layer to suppress flexibility, and punching each flexible circuit board area in a final process. (2) *The method for manufacturing a flexible circuit board according to claim (1), wherein the reinforcing layer is made of a curable resin material and is applied to the top or back surface of the flexible base material by screen printing. (3) The flexible circuit board according to claim (1), wherein the reinforcing layer is made of a sheet material and is bonded to the back surface of the flexible base material so as to include at least the non-flexible portion of each flexible circuit board region. manufacturing method.