Abstract: A highly heat conductive metal-clad laminate, which may be included in a highly heat conductive polyimide film, has a metal layer on one or both sides of an insulating layer which has a heat conductive filler-filled polyimide layer. The insulating layer of the highly heat conductive metal-clad laminate or the highly heat conductive polyimide film having the filler-filled polyimide layer is characterized in that the content of the heat conductive filler in the filler-filled polyimide layer is 20-80 wt %, the heat conductive filler contains a plate-like filler with an average length DL of 0.1-15 ?m and a spherical filler with an average particle diameter DR of 0.05-10 ?m, DL and DR satisfy the relationship DL>DR/2, no heat conductive filler of 30 ?m or more is contained, and the coefficient of thermal expansion is in the range of 10-30 ppm/K.

Abstract: Provided is a highly heat conductive metal-clad laminate which shows heat resistance, dimensional stability, workability, and adhesiveness and excellent thermal conductivity properties. Also provided is a highly heat conductive polyimide film. The highly heat conductive metal-clad laminate has a metal layer on one or both sides of an insulating layer which has a heat conductive filler-filled polyimide layer. The insulating layer of the highly heat conductive metal-clad laminate or the highly heat conductive polyimide film having the filler-filled polyimide layer is characterized in that the content of the heat conductive filler in the filler-filled polyimide layer is 20-80 wt %, the heat conductive filler contains a plate-like filler with an average length DL of 0.1-15 ?m and a spherical filler with an average particle diameter DR of 0.