Abstract: A substrate carrier for a ceramic substrate which supports one or more high power semiconductor devices which is fabricated from a metal base composite and which includes strategically located high conductivity copper based inserts to provide an effective heat transfer path to a heat sink for high power electronic devices. The coefficient of thermal expansion of both the metal based composite and the copper based inserts substantially match that of the substrate. The substrate carrier is formed by a pressure casting process where a porous preform of SiC, for example, is infiltrated with molten aluminum.

Abstract: A 100% dense, porosity free copper-chromium contact has been prepared in which deleterious porosity has been eliminated. This copper-chromium contact has been produced by pressurizing liquid copper to infiltrate an evacuated chromium based, lightly sintered, highly porous preform. The electrical contact has one of either a homogeneous Cr distribution and a graded Cr distribution. The apparatus used to effect the molten metal infiltration has two independent, physically separated chambers--a first cold chamber and a second hot chamber. The first chamber is under no applied pressure except inside a gating system used to transfer molten Cu into the porous preform in the first chamber. The new contact has about 15-30% Cr material and a high erosion resistant contact surface. The graded Cr distribution has a Cr rich layer with about 25-50% by weight Cr, an intermediate Cr layer with about 15-20% by weight Cr, a low Cr layer with about 5-15% Cr and a Cr poor layer with about 1-5% Cr above a copper substrate.