Advances in materials for optoelectronic, microelectronic and Moems/Mems packaging

Materials selection impacts performance, reliability, weight, manufacturability and cost. A variety of new advanced composite and monolithic materials are now available that provide great advantages over conventional materials for dimensional stability and thermal management in microelectronic, optoelectronic, micro-opto-electro-mechanical (MOEMS) and micro-electro-mechanical (MEMS) packaging, including: extremely high thermal conductivities (up to more than four times that of copper); tailorable coefficients of thermal expansion (from -2 to +60 ppm/K); extremely high strengths and stiffnesses; low densities; and low cost, net shape fabrication processes. Materials with low thermal conductivities and CTEs are also available. The payoffs are: improved fiber alignment; reduced thermal stresses and warpage; lower junction temperatures; simplified thermal design; possible elimination of heat pipes; weight savings up to 80%; size reductions up to 65%; increased reliability; increased manufacturing yield and cost reductions. There are many advanced packaging materials. They fall into five main categories, monolithic carbonaceous materials, metal matrix composites (MMCs), polymer matrix composites (PMCs), carbon/carbon composites (CCCs) and advanced metallic alloys. In addition to numerous aerospace industry applications, some of these materials are now being used in relatively high volume commercial products, such as servers, notebook computers, cellular telephone base stations and power supplies for trains and hybrid automobiles like the Toyota Prius. In this paper, we present an overview of what we consider the key advanced composite and monolithic materials for microelectronic, optoelectronic and MOEMS/MEMS packaging, comparing them with traditional materials.