Substrate, electronic device, electronic module, and module device

Abstract

To increase the coefficient of thermal conductivity. A substrate includes a base including a first surface and a second surface located on an opposite side of the first surface. The base has at least one recessed portion provided in the first surface. The inside of the at least one recessed portion is filled with a metal member having the coefficient of thermal conductivity higher than a coefficient of thermal conductivity of the base. In a cross section cut in a first direction orthogonal to the first surface and the second surface, a width of the at least one recessed portion in a direction parallel to the first surface decreases as a distance from a surface of one of the first surface and the second surface in which the at least one recessed portion is provided.

Dependencies are inferred from the claim text.