This invention relates to a laminate for a substrate of printed wiring board containing an insulating polyimide resin layer processible by wet etching with an aqueous solution of an alkali metal hydroxide. This laminate has a metal foil on one or both sides of the polyimide resin layer and at least one layer of the polyimide resin layer contains 5 mol % or more of a structural unit of trimellitic anhydride ester acid dianhydride having a segment derived from trimellitic acid anhydride and a segment derived from a bisphenol and shows a rate of etching of 2.0 &mgr;m/min or more by a 30 wt % aqueous solution of potassium hydroxide kept at 80° C. to which 11 wt % of ethylenediamine and 22 wt % of ethylene glycol are added.
本发明涉及一种用于印刷线路板基材的层压板,该基材含有可通过碱
金属氢氧化物
水溶液湿法蚀刻加工的绝缘聚
酰亚胺树脂层。该层压板在聚
酰亚胺树脂层的一面或两面都有
金属箔,聚
酰亚胺树脂层中至少有一层含有 5 摩尔%或更多的
偏苯三酸酐酯酸二酸酐结构单元,该结构单元具有从
偏苯三酸酐衍生的一段和从双
酚衍生的一段,其蚀刻速率为 2.0 &mgr;m/min或更快的蚀刻速度,该蚀刻速度是由保持在80°C的30 wt%
氢氧化钾水溶液(其中加入了11 wt%
乙二胺和22 wt%
乙二醇)实现的。