The development of a tool to predict package level thermal interface material performance

The characterization of thermal interface materials in electronic applications is necessary to ensure timely product launches. A tester has been developed at Intel to screen grease, phase change, and elastomer type materials, without having to go through the time and expense of completing package level measurements. The tester was designed to test materials at controlled bond line thickness and controlled pressures, while being able to directly measure the bond line thickness. The tester is capable of evaluating an interface material thermal impedance with a reproducibility of 0.03/spl deg/C/sup */cm/sup 2//W at a 95% confidence level. The tester can also be used to evaluate the bulk thermal conductivity and thermal contact impedance of a material. A package level study was completed to illustrate how tester characterization data can be used to effectively rank order interface materials.