Flexible metal-clad laminate

Abstract

Provided is a flexible metal-clad laminate, comprising; a first metal layer; a first polyimide layer having a coefficient of linear thermal expansion of 25 ppm/K or less which is formed on the first metal layer and plasma-treated; a second polyimide layer having a coefficient of linear thermal expansion of 25 ppm/K or less which is formed on the first polyimide layer.

What is claimed is: 
     
         1 . A flexible metal-clad laminate, comprising;
 (a) a first metal layer;   (b) a first polyimide layer having a coefficient of linear thermal expansion of 25 ppm/K or less which is formed on the first metal layer and plasma-treated;   (c) a second polyimide layer having a coefficient of linear thermal expansion of 25 ppm/K or less which is formed on the first polyimide layer.   
     
     
         2 . The flexible metal-clad laminate of  claim 1 , wherein an outermost layer of the second polyimide layer is made of a thermoplastic polyimide layer and the flexible metal-clad laminate further comprises a second metal layer laminated with the thermoplastic polyimide layer. 
     
     
         3 . The flexible metal-clad laminate of  claim 2 , wherein the thermoplastic polyimide layer has a thickness of 7 μm or less, a glass transition temperature of 180° C. to 300° C., and a coefficient of linear thermal expansion of 30 ppm/K or more.