| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a circuit board composed of a metal foil base and a polyimide resin insulating layer formed on it and a circuit-attached suspension board formed by the use of the circuit board, wherein the circuit board is hardly warped, and polyimide resin is set small and nearly equal in thermal linear expansion coefficient to the metal foil base so as to protect the resin insulating layer against cracking or delamination. SOLUTION: A circuit board is composed of a metal foil base and a polyimide resin insulating layer formed thereon, wherein the polyimide resin is obtained through a process where (A) p-phenylenediamine and (B) acid anhydride composed of (a) 3,4,3',4'-biphenyl tetracarboxilic acid dianhydride and (b) 2,2-bis(3,4- dicarboxy phenyl)hexafluoropropane are made to react on each other. A circuit- attached suspension board is formed through a patterning technique where a required circuit of conductor layer is formed on the above circuit board.</p> |
