Unitary slotted heat sink for semiconductor packages

Claim 1

In a fluid cooled high density integrated circuit semiconductor device module having a substrate with a plurality of semiconductor devices operatively mounted thereon, a lid element mounted on the substrate forming an enclosure for the semiconductor devices, and I/O terminals on said substrate, the improvement comprising a unitary heat sink formed of heat conductive material bonded to said lid element for dissipating heat generated by said semiconductor devices, said heatsink having a plurality of cooling fin elements arranged in columns and rows and positioned orthogonally relative to the top surface of said lid, said fin elements having slots in the lower end that terminate short of the top of the fin element and which divides the lower end of each of the fin elements into a plurality of leg sections, said heat sink having a plurality of flat quadralateral base portions individually bonded to said lid, said leg sections of an individual fin element being attached to different quadralateral base portions with adjacent fin elements supported by adjacent common base portions, in operation said heatsink reducing stresses at the bonded interface of the heatsink and lid by flexure of said leg sections while providing effective large area heat transfer through the lid element to said fin elements.