| 摘要 |
PURPOSE:To obtain bonding material wherein heat dissipating properties are not deteriorated and large voids are not generated when a bonding material layer is thickened in order to ease the stress generated between a semiconductor element and a substrate, by forming an alloy soldering layer of 5mum or more in thickness whose base metal is lead or tin, on both surfaces of a silver core member. CONSTITUTION:Composite material composed of a three-layered structure having core material which is not fused at the time of bonding is used, and bonding is performed by using an alloy soldering material film of the layer surface. As the core material, silver is used and on its surface, an alloy soldering material film whose base metal is lead or tin is formed to be 5mum thick or more. Silver is not fused at an ordinary temperature condition where a silicon chip 1 and a substrate like a lead frame are bonded. Hence an original shape is almost maintained after bonding, and a constant bonding material layer can be ensured between a silicon chip and the substrate. When voids are generated by bonding the silicon chip and the substrate, the void size is restricted by the silver layer and does not increase. |
