Patent ID: 6875519

Claim:
A two-layer copper polyimide substrate comprising at least a polyimide film, a single metal seed layer formed directly on the polylmide film, and a copper layer consisting of copper formed on the metal seed layer, wherein the surface of the polyimide film contacted by the metal seed layer includes a polyimide modified layer having a thickness of not more than 200 Å as evaluated by the silver nitrate dyeing method, wherein the adhesion strength as evaluated by at least one of an initial adhesion, a heat resistant adhesion after standing in air at 150° C. for 168 hours, and a PCT adhesion after PCT test at 121° C. and at a humidity of 95% under 2 atmospheres for 100 hours is 400 N/m or more with a thickness of the copper layer of copper of 8 μm.