ISOTROPIC ADHESIVE FILM AND FLEXIBLE METAL-CLAD LAMINATE

摘要

With respect to the dimensional change of flexible metal-clad laminate, although attention has been drawn to only the direction of film flow (referred to as MD direction) and the transverse direction of film (referred to as TD direction), reducing of the dimensional change of flexible metal-clad laminate is increasingly demanded in not only the MD and TD directions but also the directions angling 45° right and left from the MD direction in accordance with the progress of miniaturization of wiring. There is provided an adhesive film comprising a polyimide film and, superimposed on at least one major surface thereof, an adhesive layer containing a thermoplastic polyimide, characterized in that the adhesive film exhibits a degree of orientation of = 1.3.