Power Devices Sandwiched Between Silver-Diamond Parts for High Performance Module

Devices sandwiched between high thermal conductivity Silver Diamond (AgD) clip and spreader can be an effective, simple and reliable solution to significantly reduce the package thermal resistance. The thermal performance of such package is compared to conventional wire bonded devices for assemblies with and without baseplate. Results show that global thermal resistance improvement varies between 30% and 48% for power module without baseplate and between 25% and 42% when a baseplate is used. Using the same solution with Cu clip and spreader, the ratio of improvement does not exceed 32% in the best case. Moreover, the coefficient of thermal expansion mismatch between AgD and power device is low. Hence, AgD clip and spreader allow reducing the maximum Von-Mises stresses in the solder by at least 63% compared to copper ones.