Package embedded heat exchanger for stacked multi-chip module

This paper describes a polymer type micro-heat exchanger applicable to 272 BGA multi-chip module (MCM). Usually stacked MCM becomes easily overheated at low dissipated power due to the lack of heat path. To overcome this problem, we fabricated a polymer type micro-heat exchanger between chips. Normally, the heat exchanger is fabricated by high thermal conductive substrate such as metal, silicon, etc. Even though it shows efficient ability of heat exchange, it is currently too large to be applied present package technology when it is integrated into a package. Therefore, a package technology that can integrate a micro-heat exchanger and that would be fabricated using the present packaging technology is needed. We fabricated the PDMS beat exchanger which is 300 mum height using SU-8 photoresist mold. This speculation satisfied integration condition to the generally packaged MCM, and there was no need for additional space for integration. Consequently, we were able to reduce thermal resistance from 50 to 7 degreesC/W by the liquid cooling method and show parametric optimization to design a heat exchanger using polymer. (C) 2004 Elsevier B.V. All rights reserved.