Thickness Control for Fusible Alloys
Original Publication Date: 1985-Nov-01
Included in the Prior Art Database: 2005-Feb-19
When a fusible alloy forms the thermal joint between a circuit chip and its cooling structure, an accompanying nonsoftening powder of desired particle size can be used to establish minimum thickness during softening of the alloy. The powder, such as ground and sifted silicon, can either be sprinkled on a preform of the alloy or mixed in the alloy to limit collapse. Particle density of the powder should be kept low to prevent clusters so that the alloy film will be thin and uniform. Other materials, such as metals, may be used, but they may form intermetallics with the alloy.