Method for manufacturing flexible wiring circuit board

Abstract

The present invention provides a method for manufacturing a flexible wiring circuit board having an insulating support film and, formed thereon, a wiring circuit, which comprises the following steps (a) to (d): (a) a step of adhering pressure-sensitively a laminate comprising the insulating support film and an electroconductive layer formed thereon to a transparent hard substrate by the use of a pressure-sensitive adhesive layer from the insulating support film side of the laminate; (b) a step of patterning the electroconductive layer of said laminate, to form the wiring circuit; (c) a step of reducing the adhesion strength of said pressure-sensitive adhesive layer; and (d) a step of peeling the laminate having the wiring circuit formed thereon from the transparent hard substrate so as for the pressure-sensitive adhesive layer to remain on the transparent hard substrate.

Description

technical field [0001] The invention relates to a method for manufacturing a flexible wiring circuit board. Background technique [0002] At present, the flexible wiring circuit board widely used is obtained by the following method. That is, a copper foil with a thickness of ≤35 μm laminated on one side of a polyimide base film with a thickness of ≤25 μm is patterned by a subtractive method to form a circuit. [0003] As a method of manufacturing the above-mentioned flexible wiring circuit board by roll-to-roll (Roll-to-Roll), a method having the following characteristics is proposed: a copper-clad laminate is adhered to a carrier with an adhesive that reduces adhesion when exposed to light. On a film (see Patent Document 1: Japanese Patent Application Laid-Open No. 7-99379). [0004] In this manufacturing method, the polyimide film substrate is bonded with a copper clad laminate having a structure of copper foil, and the side surface of the polyimide film substrate is bon...

AI Technical Summary

Problems solved by technology

[0006] However, with the increase in density of electronic equipment in recent years, under the current situation that the thinning and high density of flexible wiring boards are progressing, in the manufacturing method disclosed in the above-mentioned Patent Document 1 using a tape carrier, when When the pattern pitch of the circuit is ≤40μm, there is a problem that the accuracy of pattern formation is reduced due to the influence of surface deformation or unevenness of the tape carrier

In addition, there is also the problem that the cutting chips at both ends of the tape carrier or the adhesive exposed on the cut surface will easily cause poor patterns.

[0007] In addition, when implementing the manufacturing method disclosed in Patent Document 1, since a roll unwinder and a coiler are necessary, it is difficult to miniaturize the equipment, and the running cost of the incidental equipment is also high. Therefore, the time for condition optimization and rollback is also long, so there is a problem of long lead time

[0008] In addition, after the copper foil pattern is formed, when punching the copper clad laminate as needed, the metal die punching method is used, so there may be burrs at the end of the cut surface, or the flexible wiring circuit may be damaged. The board itself is prone to problems such as deformation

In addition, since expensive metal molds must be produced for each flexible wiring board having a different circuit pattern, there is a problem that the punching process cost cannot be suppressed

[0009] In order to solve this problem, the laser cutting method can be considered, which can easily make various punching patterns by changing the program. However, when using the laser cutting method to punch out the flexible wiring circuit board, since the tape carrier is also cut at the same time, there is a problem. The problem that the flexible wiring circuit board cannot be held on the tape carrier, the workability is greatly reduced, and the occurrence rate of defective products is also increased

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