Pressure controllable encapsulated liquid thermal interface

Abstract

Heat is transferred to a cold plate from one or more subassemblies in an array of subassemblies in an electronic package. The cold plate has a thermally conductive cold plate substrate, a pressure header, a pressure passage, and one or more pressure connections. Each of the pressure connections connects through a housing opening to housing volume defined by a flexible housing in an encapsulated liquid thermal interface (LTI). The flexible housing is in physical and thermal contact with one of the subassemblies through a housing bottom and a top surface of one or more components in the subassembly. A thermally conductive fluid fills the housing volume, housing opening, pressure connections, pressure passage, and pressure header which are all in fluid communication along with one or more other connections, housing openings, and LTIs on other subassemblies. The system transfers heat from the subassemblies to the cold plate while maintaining a constant pressure/stress on each of the subassemblies. The system pressure on each of the subassemblies is equal. The system pressure can be controlled to a preloaded pressure to insure good electrical contact between components. Shear on the subassemblies is minimized by the LTIs.