挠性电路板覆盖膜耐热可靠性改善

The improvement of thermal reliability of coverlay on Flexible Printed Circuit Boards

在刚挠结合板的热应力测试中,挠性区域的耐热性是其中的薄弱环节,易出现覆盖膜分层起泡、字符脱落等不良,文章针对挠性电路板的耐热可靠性进行了改善探讨,从覆盖膜快压参数、热固化参数、覆盖膜表面粗化方式等方面进行了工艺试验,提出了有效的改善对策,可满足5次以上热应力测试要求,对挠性电路板的耐热可靠性有明显提升。

In the thermal stress test of the rigid-flex board,the heat resistance of the flexible area is the weak link,and defects such as lamination and blistering of the cover film and characters falling off are prone to occur.This paper focuses onthe heat resistance reliability of the flexible circuit board.In order to improve the discussion,the process tests were carried out from the aspects of the fast pressure parameters of the cover film,the thermal curing parameters,and the surface rougheningmethod of the cover film.Effective improvement measures were put forward,which can meet the requirements of more than 5 thermal stress tests.The thermal reliability has been significantly improved.