High-Performance Thermal Management Materials
. by Carl Zweben, Ph.D.,
In response to well-recognized needs, there have been revolutionary advances in thermal management materials. Silicon carbide particle-reinforced aluminum (Al/SiC), which was first used in thermal management by the speaker’s group at GE in the 1980s, is now well established. By replacing a copper base plate with Al/SiC, one IGBT supplier “eliminated solder fatigue”, extending guaranteed life from 10 to 30 years. There are an increasing number of new materials with low coefficients of thermal expansion (CTEs) and low densities having thermal conductivities up to 1700 W/m-K. Some are cheaper than traditional materials. Payoffs include: increased reliability; reduced junction temperatures and weight; low-CTE, thermally conductive PCBs, potentially eliminating the need for underfill; CTE matching allows direct attach with hard solders, reducing thermal resistance and solder fatigue. There are a large and increasing number of microelectronic and optoelectronic applications, including: PCBs and PCB cold plates; heat sinks; microprocessor, RF and power modules; heat spreaders and sinks; LED and laser diode modules; thermoelectric coolers; plasma and LCD displays; detectors; and photovoltaics. This presentation covers the large and increasing number of advanced thermal management materials, including properties and the growing array of applications.