Patent ID: 9685391
Date: 2017-06-20
CPC Classifications: H01L

Claim:
1. A wiring board, comprising: a substrate having first and second opposite surfaces; a first adhesive layer on the first surface of the substrate; a thermal diffusion metal pattern not to be electrically connected to a semiconductor device to be mounted on the wiring board, the thermal diffusion metal pattern being on the first adhesive layer; a plurality of vias vertically extending from the thermal diffusion metal pattern into the substrate through the first adhesive layer with a gap around each of the vias in the substrate and the first adhesive layer; and a second adhesive layer on the second surface of the substrate, the second adhesive layer filling in the gap around each of the vias within the substrate and the first adhesive layer, wherein the gap around each of the vias includes a first gap around each of the vias in the substrate and a second gap around each of the vias in the first adhesive layer, and wherein the second gap has a lateral size greater than a lateral size of the first gap.