Opening intensive type printed circuit board covering film

Abstract

Disclosed in the invention is an opening intensive type printed circuit board covering film comprising a polyimide film, an adhesion layer, and a piece of release paper. The release paper is formed by a release agent layer, a first PE layer, a body paper layer and a second PE layer successively. The thickness of the release agent layer is less than 1 micrometer, the thickness of the first PE layer is 10 to 20 micrometers, the thickness of the body paper layer is 40 to 60 micrometers, the thickens of the second PE layer is 10 to 30 micrometers, and the thickness of the release paper is 90 to 100 micrometers; and the basis weight of the release paper is 40 to 60g/m<2> and the release force of the release paper is 2 to 8g/5cm. Because the release paper with low basis weight, low thickness and low release force is used, the covering film has performance of low basis weight and low hygroscopicity and the excellent curling-resistant performance, so that the covering film is especially suitable for the high-density small hole opening and half-cutting printed circuit board. Therefore, the environment protection requirement is met; the environment pollution is reduced; the paperless trend of the covering film in the industry is followed; and the sustainable development demand can be satisfied.

Description

technical field [0001] The invention relates to a cover film applied to a printed circuit board, in particular to a cover film used for an opening-intensive printed circuit board. Background technique [0002] Printed circuit boards are an indispensable material in electronic products, and as the demand for consumer electronics grows, the demand for printed circuit boards is also increasing day by day. Due to the characteristics of flexibility and three-dimensional wiring, flexible printed circuit boards are currently widely used in computers and their peripheral equipment, Communication products and consumer electronics products, etc. [0003] Generally speaking, a flexible printed circuit board is mainly composed of a copper foil substrate (FCCL) and a cover film (CL). Generally, a polyimide film is used to make the cover film, or a thin insulating layer is formed by screen printing technology. The ink acts as a cover film. These known cover films have problems such as ...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the above-mentioned defects, the present invention provides a cover film for an opening-intensive printed circuit board. The cover film for an open-intensive printed circuit board of the present invention has the functions of low basis weight, low hygroscopicity and excellent curl resistance. It is suitable for high-density small-hole and semi-cut printed circuit boards, responding to environmental protection requirements, reducing environmental pollution and following the trend of paperless cover film in the industry, meeting the needs of sustainable development

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