| 摘要 |
PURPOSE: To obtain effective engagement between through holes, by a method wherein first and second conductive through holes have a first metal layer, the second conductive through hole has further a second metal layer, a compressive stress is applied to a conductive through hole formed by aligning the first and second through holes, and then applying heat for metal bonding. CONSTITUTION: In a through hole of a subassembly 20, gold is used as first metal 61 which is added to copper for forming a land 53 and a cylinder part 63. In a through hole of a subassembly 30, tin is further used as second metal. The subassemblies 20 and 30 are so aligned that the respective land parts 53 of through holes 50 accurately coincide with each other. Both layer assemblies are engaged with each other, to which an adequate pressure is applied. The compressed subassemblies are heated at a temperature rather exceeding the eutectic melting point of the gold layer and the tin layer, and then heated at a higher temperature. Dielectric material is fused, and the two subassemblies complete bonding, and then are cooled at a specified speed. |
