Patent ID: 9730332
Date: 2017-08-08
CPC Classifications: C25D,H05K,Y10T

Claim:
1. A surface treated copper foil to be laminated on a polyimide having a ΔB (PI) to be defined as follows of 50 or more and 65 or less before being laminated to the copper foil so as to form a copper clad laminate comprising: a surface having a color difference ΔE*ab of 50 or more based on JIS Z 8730 through the polyimide when the copper foil is laminated on the polyimide; and a difference between the top average Bt and the bottom average Bb in a brightness curve extending from an edge of the copper foil to a portion without the copper foil ΔB (ΔB=Bt−Bb) of 40 or more; wherein the brightness curve is obtained from an observation spot versus brightness graph of measurement results of the brightness of the photographed image of the copper foil through the polyimide when the copper foil is laminated on the polyimide from the surface treated surface side of the copper foil with a CCD camera for the respective observation spots along the direction perpendicular to the extending direction of the observed copper foil.