A resin film, a metal-clad laminate, a circuit board, and a laminate structure

Provided is a resin film that is a thin film and yet ensures heat dissipation characteristics and mechanical strength within a practically sufficient range. The resin film 10 includes a film-like insulating resin 11 and a thermally conductive filler 12 dispersed in the insulating resin 11. The thickness of the entire resin film 10 is within a range of 8 micro m or more and less than 23 micro m, the thermal conductivity (? z) in the thickness direction is within a range of 0.3 W/m K or more and less than 2.0 W/m K, The volume average particle diameter of the heat conductive filler 12 is preferably in a range of more than 1.0 micro m and less than 5 micro m, and the ratio (D/L ratio) of the volume average particle diameter (D) to the film thickness (L) is preferably in a range of 0.15 to 0.50. Figure...