| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent such trouble that the cavity caused by short filling arises in a through conductor and the electric resistance becomes large, which makes it unable to actuate normally a semiconductor integrated circuit element mounted on a wiring board. SOLUTION: In this wiring board, the insulating layer 1a of the surface layer of an insulating substrate 1 being made by stacking a plurality of insulating layers 1a-1d where wiring conductors 4-6 are arranged on the surface is provided with first through conductors 4a-6a 100μm or over in diameter and second through conductors 4b-6b under 100μm in diameter, and the first through conductors 4a-6a are made of conductors consisting of coupled metallic powder, and metallic layers 8 covering the exposed surface, and the second through conductors 4b-6b are made of plated metal. The increase of electric resistance caused by short filling or the electric short circuit caused by oozing of conductor paste does not occur in the through conductors 4a-6a and 4b-6b.</p> |
