| 摘要 |
Provided is a multilayer wiring substrate capable of reliably preventing missing vias and having excellent connection reliability. This multilayer wiring substrate (10) has a multilayer build-up structure comprising multiple resin insulation layers (33) and multiple conductor layers (42) laminated in an alternating manner. The resin insulation layers (33) contain a glass cloth (51) in the inner layer of a resin insulation material (50). Via holes (43) are formed in the resin insulation material (50) of the resin insulation layers (33), and through-holes (52) are formed in the glass cloth (51) at positions corresponding to the via holes (43). The parts of the glass cloth (51) at the edges of the through-holes (52) protrude further inward than the inner wall surface of the via holes (43) and are embedded into the side portion of a via conductor (44). By welding and connecting glass fibers (57), welds (58) are formed at the ends of the glass fibers (57) protruding from the inner wall surface (54) of the via holes (43). |
