Dimensionally Controlled Semiconductor Package
Original Publication Date: 1984-Feb-01
Included in the Prior Art Database: 2005-Feb-02
In order to obtain efficient heat dissipation in a semiconductor package using a thermal compound to convey heat from the chip to the heat sink, it is imperative that the gap between the chip and the heat sink, which is filled with a thermal compound, be controlled within a very close tolerance. The thickness of the seal between the cap and substrate exerts a profound influence on the thickness of this gap. The thickness dimension of the seal is relatively hard to hold within required tolerances. In this process a lead-tin alloy preform 10 is fabricated to facilitate hermetic sealing of the cap. In the four corners of the preform 10 are located copper disks 12 during manufacture of the preform.