Here is the abstract you requested from the Automotive_2007 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Die Casting of Thermal Management Components from Low-Cost Aluminum Metal Matrix Composites|
|Keywords: aluminum metal-matrix composites, die casting, packaging|
|Most current microelectronic packaging components such as thermal spreaders, package stiffeners and heat sinks are made of monolithic aluminum or copper, or from aluminum–silicon carbide (Al-SiC) composites produced by powder metallurgy or from performs infiltrated by liquid aluminum. This paper will describe a new low-cost method for the production of microelectronic packaging components by pre-mixing the silicon carbide particles into molten aluminum followed by the die casting of near-net shape components. A new proprietary rapid mixing technique has been developed by MC-21, which utilizes a modular mixing system composed of a melter, an MMC mixer, and a holder. The high efficiency of the rapid mixing process allows lower cost ceramic particles possessing wider size distributions to be used in the process. The more efficient process can also use finer particles which produce MMC which is easier and less expensive to machine. In addition, the modular MMC mixing system can be installed at the foundry site, thus facilitating the feeding of molten MMC directly into the casting machine from the mixing system. This eliminates the need to cast MMC ingots which must then be transported and remelted prior to shape casting. These cost savings have enabled MMCs to be used in or considered for new automotive and electronic applications. The MC-21 rapid mixing process has been shown to produce extremely uniform silicon carbide (SiC) particle distributions up to 45 volume % (50 weight %) in aluminum. Measured physical and mechanical properties of the composites will be described, which include Young’s moduli up to 175 GPa and thermal expansion coefficients down to 10.5 ppm/oC (which are respectively 2.3 times higher and less than half that of monolithic aluminum alloys). Near-net shape components can be produced from these composites by either conventional die casting or squeeze casting. The casting of the composites will be described, illustrating the types of components that can be produced.|
|Stephen P. Midson, President
The Midson Group, Inc.