US Patent 7537151 Method of making high performance heat sinks

A method of heat sink manufacture in which the crests of a conductive fin are nested down into close fitting grooves in a flat, conductive base plate, with small interface gaps G. A compressive material is set inside the fin crests and the grooves, viscous enough to not intrude into the gaps G, to a level sufficient to substantially fill the grooves. The work piece thus created is subjected to a cold hydrostatic oil bath, crushing the outer surfaces of the fin crests into the internal surfaces of the grooves where the compressed seal covers, while the rest of the fin is supported against net deformation by the surrounding oil.