Method of manufacturing flexible film

Abstract

A method of manufacturing a flexible film is disclosed. The method includes (a) forming at least one hole on an insulating film, (b) after the step (a), forming a first metal layer on a first surface corresponding to an inner circumferential surface of the hole, and at least one of a second surface corresponding to an upper surface of the insulating film and a third surface corresponding to a lower surface of the insulating film, and (c) forming a second metal layer on the first metal layer. A thickness of the first metal layer is smaller than a thickness of the second metal layer.

Description

[0001]This application claims the benefit of Korean Patent Application No. 10-2008-0049497 filed on May 28, 2008 and No. 10-2008-0123826 filed on December 8, the entire contents of which is hereby incorporated by reference.BACKGROUND[0002]1. Field[0003]Exemplary embodiments relate to a flexible film, and more particularly, to a method of manufacturing a flexible film used in various electrical devices.[0004]2. Description of the Related Art[0005]A flexible film may be used in various electrical devices. As an example of the flexible film, there are a flexible printed circuit board (FPCB) and a flexible copper clad laminate (FCCL).[0006]A metal layer of the FPCB or the FCCL is manufactured using a sputtering method, a casting method, or a laminating method.[0007]In the sputtering method, a sputtering process is performed on a polyimide film to form a metal layer. In the casting method, liquid polyimide is coated on a metal thin film, and then a casting process is performed to thereby...

AI Technical Summary

Benefits of technology

This patent describes a method for making a flexible film with good stability and reliability. The method involves forming at least one hole on an insulating film, and then sequentially adding layers of metal to the inner and outer surfaces of the hole. The first layer is made of copper and nickel, while the second layer is made of copper or gold. The insulating film can be made of polyester, polyimide, liquid crystal polymer, or fluorine resin. The ratio of the thickness of the first layer to the second layer can be between 1:2,500 and 1:400 to 1:500. The method can also involve preprocessing the insulating film before adding the metal layers. The technical effects of this method include improved stability and reliability of the flexible film.

Problems solved by technology

In the sputtering method, because the surface of the polyimide film is damaged, the smoothness is reduced.

In the casting method, kinds of usable polyimide films are limited.

In the laminating method, it is not easy to manufacture the FPCB or the FCCL because of a limitation of physical properties of the used adhesive.

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