| abstract |
The present disclosure relates to a circuit board having a first polyimide cover layer, a first imaged metal layer, a first electrical insulation layer, a second imaged metal layer, a polyimide adhesive layer, a first Three imaged metal layers, a second electrical insulating layer, a fourth imaged metal layer and a second polyimide overcoat layer. The first polyimide cover layer, the polyimide adhesive layer and the second polyimide cover layer are derived from 100 mole % 3,3',4,4'-biphenyl Tetracarboxylic dianhydride, 20 to 90 mole percent 2,2'-bis(trifluoromethyl)benzidine, and 10 to 80 mole percent 4,4'-diaminodiphenyl ether. |