Abstract: An hermetically sealed, air-less multi-chambered structure for cooling semiconductor chips mounted on a substrate or printed circuit board which employs means for selectively providing a boiling-coolant generation of vapor bubbles for cooling purposes.

Abstract: An apparatus for containing and cooling high-density integrated circuit packages includes a housing in which the circuit package is sealingly mounted in an internal chamber of said housing. The chamber is at least partially filled with a plurality of thermally conductive spheroids which are biased into thermally conductive contact with each other and with the integrated circuit package to maximize the heat exchange surface. The apparatus includes an inlet and an outlet for passing a dielectric immersion coolant through the chamber in direct heat exchange relationship with the spheroids and with the high-density integrated circuit package.