| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyimide film with excellent film formability, having high elastic modulus, low coefficient of thermal expansion, and alkali etching ability when applied to the substrate of a metal circuit board such as a flexible print circuit(FPC), a chip size package(CSP), a ball grid array(BGA) or a tape automated bonding(TAB) on the surface of which a metal circuit is made, and to provide a metal circuit board using it as a substrate. SOLUTION: This polyimide film is obtained from a block- or IPN-polyamic acid comprising pyromellitic acid dianhydride and 10 to 90 mol% of 4,4'- oxydianiline and 10 to 90 mol% of 3,4'-oxydianiline both based on total diamine. Preferably this polyimide film is obtained from a polyamic acid comprising pyromellitic acid dianhydride and 20 to 80 mol% of 4,4'-oxydianiline and 20 to 80 mol% of 3,4'-oxydianiline both based on total diamine. |
