| abstract |
(57) [Summary] [Structure] The protective film in the flexible printed circuit board of the present invention is such that 50 mol% or more of the acid component is a diphenyl ether tetracarboxylic acid component, and the diamine component is 50 to 99 mol% of an aromatic diamine. And a silane coupling agent, and a polyimide resin containing 50 to 1 mol% of diaminosiloxane. [Advantages] The present invention provides a protective film in which a silane coupling agent is contained in a specific polyimide resin, so It has excellent adhesiveness and can be processed at low temperature, and by using this, highly reliable electronic devices can be manufactured. |