Semiconductor unit and method of manufacturing a semiconductor unit

摘要

A semiconductor unit comprises: an insulating substrate (1) formed by integrating a ceramic base plate (1b) and a cooling fin (1a); a plurality of inter-plate connectors (5); and a plurality of semiconductor elements (3a). The one sides of the semiconductor elements (3a) are bonded to the ceramic base plate (Ib) of the insulating substrate (1) with a solder (4) on the chip underside, and the other sides thereof are bonded to the chip with a solder (6) - Top side bonded to the inter-plate connecting elements (5) in such a way that the inter-plate connecting elements (5) correspond to the semiconductor elements (3a), respectively. The solder (4) on the underside of the chip and the solder (6) on the top of the chip both contain predominantly Sn and 0.3 wt.% To 3 wt.% Ag and 0.5 wt.% To 1 wt.% Cu. This enables the dimensions of the semiconductor unit to be reduced without impairing heat dissipation.