摘要 |
<p>A two-layer copper polyimide substrate includes a modified layer on the surface of a polyimide film having a thickness of not more than 200 Å, and preferably not less than 50 Å, as evaluated by a method by dyeing a section thereof with a silver nitrate aqueous solution and observing it by a transmission electron microscope (TEM). A metal seed layer is formed on the polyimide film surface, followed by forming a copper layer thereon by copper electroplating or copper electroless plating or a combination of the both, providing a two-layer copper polyimide substrate in which any 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 are 400 N/m or more.</p> |