| 摘要 |
<p>A wiring board having a high reliability in the insulation and connection of wiring layers, and a production method thereof, the wiring board comprising wiring layers (407) consisting of at least two layers, insulation layers (402) interposed between wiring layers and containing organic resin, and vias (507) provided in insulation layers and extending up to the wiring layers, wherein vias contain functional matters (403) and clearances (404) with part of the clearances (first clearances) having organic resin seeped thereinto from insulation layers and the remaining clearances (second clearances) still filled with air, whereby the flowing of conductive paste into insulation layers, or so called paste bleeding, is eliminated, the second clearances in vias act to lower or soften the modulus of elasticity of the vias as a whole, and a stretching follow-up in response to a mechanical stress on the wiring board is improved to prevent the both wiring layers from being wire-broken to thereby ensure high reliability in electrical and mechanical connections between the both wiring layers.</p> |
