挠性板压合补强缺陷改善

摘要

Stiffener lamination of FPC to strengthen support flexible substrates is always one of the vital steps in FPC producing process. Stiffener lamination requires the use of thermosetting adhesive as bonding. Due to the existence of the gap between the circuit substrate and the flexible plate, the difficult problem of AD underfilling always exist in the lamination process, adhesive filling full or not directly affect the product reliability and durability. By studying the resin filling difficulties in different circuit layout, a simple relationship based on a series of line spacing under different copper thickness was given through resin filling requirement and CVL bending depth, the selection principle of the thickness of the stiffener adhesive. Also different conforming type way were contrast, filling voids and pad depression made to analysis to improve, the better improve way was given by not change the lamination parameters.%挠性板生产过程中,在板上局部位置压合补强板以加强对挠性基板的支撑和方便插接是关键流程之一。补强热压时一般是采用半固化态且流动性相对较小的热固性等胶作为粘结,且由于一些补强板刚性大变形小,因此补强的压合过程存在填胶难的问题,胶的填充饱满与否直接影响到产品的可靠性和耐用性。通过研究不同的线路布置时填胶的难易,根据不同铜厚下的系列线路间距所需填胶量与覆盖膜弯曲深度的简单关系,提出了补强压合胶厚的选择原则;同时通过覆型方式的对比,对填胶空洞和焊盘凹陷等做出改善分析,在不改变压合参数的前提下给出了可行的改善途径。