APPLICATION OF DIAMOND SUBSTRATES FOR ADVANCED HIGH-DENSITY PACKAGING

The increased speed of integrated circuits (ICs) is accompanied by increased power levels and the need to package the IC chips very close together in order to realize that speed at the system level. Combined, these spell very high power densities and severe thermal problems at the package level, which are difficult to deal with satisfactorily using conventional packaging materials. Recently, the promise or major reductions in the price of synthetic diamond has allowed its consideration for use in electronic thermal management applications, such as multichip module (MCM) substrates, requiring many tens of grams of material (e.g. substrates 100 mm square and 1 mm thick). Because of the combination of extremely high thermal conductivity and an electrically insulating nature, diamond is an ideal IC packaging or MCM substrate material, not only for reducing chip temperatures in conventional 2D MCM configurations but also in making it practical to implement advanced 2D package configurations and ultrahigh performance, three-dimensionally interconnected MCM packaging approaches. These advanced packaging concepts are made possible because diamond can cool, through lateral thermal conduction to board edges alone, MCMs with many hundreds of watts of power dissipation and at the same time allow for a high density of vertical via interconnects through the diamond substrate.