| abstract |
The present disclosure is directed to a circuit board having a first imaged metal layer, a first electrically insulating layer, a second imaged metal layer, a polyimide bondply derived from 100 mole % 3,3′,4,4′-biphenyl tetracarboxylic dianhydride, 20 to 90 mole % 2,2′-bis(trifluoromethyl)benzidine, and 10 to 80 mole % 4,4′-oxydianiline, a third imaged metal layer, a second electrically insulating layer and a forth imaged metal layer. The circuit board does not have an adhesive layer between the second imaged metal layer and the polyimide bondply or the third imaged layer and the polyimide bondply. |