| 摘要 |
<p>PURPOSE:To obtain a solder material for joining a semiconductor chip and a base material, capable of minimizing the thermal stress applied to the semiconductor chip after joining, and a joining method. CONSTITUTION:Secondary soft solders 5a, 5b with low melting point are provided to both sides of a primary soft solder 4 with high melting point. A semiconductor chip 1 is laid via the above solder material on a base material 2, and heating is done in a reducing atmosphere up to a temp. between the melting point of the secondary soft solders 5a, 5b and the melting point of the primary soft solder 4 to melt the secondary soft solders 5a, 5b and then the secondary soft solders 5a, 5b are solidified to join the semiconductor chip 1 and the base material 2.</p> |
