| 摘要 |
<p>A both-sided circuit substrate having metallic via holes and used suitably as a submount for mounting a semiconductor element, and a method for efficiently producing a substrate ensuring good electrical contact between the metallic via holes and a circuit pattern and facilitating positioning of an element being bonded. The ceramic substrate having via holes internally filled with a conductive material has surface roughness Ra≤0.8 μm at the ceramic part on at least one side of the ceramic substrate. A substrate where the conductive material filling the via holes existing on at least one side is projecting by 0.3-5.0μm from the surface is employed as a material substrate and after a conductive layer is formed on the surface thereof, the conductive layer is patterned or a solder film for mounting an element is formed based on the position of protruding parts of the conductive layer resulting from the via holes existing beneath the conductive layer.</p> |
