Here is the abstract you requested from the rf_2009 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.
|New Aluminum-Silicon Carbide Composites for Air Cavity Package Applications|
|Keywords: AlSiC, Thermal Management, Air Cavity Package|
|The commercial availability of liquid crystal polymer (LCP) air-cavity packages for LDMOS and similar devices has provided benefits for end users, yet challenges with these materials exist as well. With its lower cost and higher frequency capabilities, LCP has become very attractive as a replacement for ceramic-based packaging materials. However, as device performance has driven both frequency and power demands upward, the resultant thermal management issues must be dealt with at the package level. While traditional copper-tungsten and copper-molybdenum heat-spreaders or flanges can be used with LCP for high-reliability applications, a new generation of aluminum-silicon carbide (AlSiC) composites has proven to be a lower-cost and higher performance option. Recent developments in silicon carbide preform processing and AlSiC manufacturing technology has led to the introduction of improved Al/SiC composites with coefficient of thermal expansion values as low as 4.8 ppm/¡ãC, and thermal conductivity values as high as 255 W/mK. These new composites allow close matching of the thermal expansion of the package¡¯s heat spreader to silicon, gallium arsenide, or gallium nitride power devices, minimizing solder or epoxy attachment layer stresses. In addition, taking advantage of the high thermal conductivity of these new composites, the overall thermal performance of the package can be enhanced, resulting in more efficient operation of the power device. The work presented will provide an overview of the development of these new AlSiC composites, as well as their first commercial applications in LCP air-cavity type packages.|
|Dan White, President
Thermal Transfer Composites LLC
New Castle, DE