Patent ID: 9596757
Date: 2017-03-14
CPC Classifications: B32B,C08G,H01B,H05K,Y10T

Claim:
1. A circuit board, comprising in the following order: a. a first imaged metal layer b. a first electrically insulating layer having a first side and a second side; the first side of the first electrically insulating layer is next to the first imaged metal layer c. a second imaged metal layer; the second side of the first electrically insulating layer is next to the second imaged metal layer; d. a polyimide bondply comprising a polyimide derived from 100 mole % 3,3′,4,4′-biphenyl tetracarboxylic dianhydride, based upon a total dianhydride content of the polyimide, 20 to 90 mole % 2,2′-bis(trifluoromethyl) benzidine, based upon a total diamine content of the polyimide, and 10 to 80 mole % 4,4′-oxydianiline, based upon the total diamine content of the polyimide; e. a third imaged metal layer; f. a second electrically insulating layer having a first side and a second side; the first side of the second electrically insulating layer is next to the third imaged metal layer g. a fourth imaged metal layer; the second side of the second electrically insulating layer is next to the fourth imaged metal layer; wherein the polyimide bondply is in direct contact with the second imaged metal layer and exposed areas of the second side of the first electrically insulating layer; and in direct contact with the third imaged metal layer and exposed areas of the first side of the second electrically insulating layer; and wherein the polyimide bondply has a peel strength from 0.7 to 2 N/mm as measured in accordance with IPC-TM-650-2.4.9d, when i) the first imaged metal layer, the first electrically insulating layer and the second image metal layer; ii) the polyimide bondply; and iii) the third imaged metal layer, the second electrically insulating layer and the fourth imaged metal layer; are laminated at a lamination temperature from 300 to 380° C. and a pressure from 150 psi (10.55 Kg/cm) to 400 psi (28.13 Kg/cm); and wherein the first electrically insulating layer and the second electrically insulating layer are any electrically insulating material that can withstand the lamination temperature from 320 to 380° C.