On-chip heat dissipation design for high-power SiP modules with LTCC substrates

In a system-in-package (SiP), a large number of devices with different functions are integrated in a single package. A good cooling system is crucial for the performance of the SiP, especially when high-power devices are included. In this work, cooling for high-power SiP modules with low temperature co-fired ceramic (LTCC) substrates were studied. Metal pillar arrays as well as microfluidic cooling channels were embedded in the LTCC substrates to enhance the heat transfer process both passively and actively. The finite element method was used to perform multi-physics coupling simulations. The temperature distribution throughout the substrate and the chip as well as the fluid flow field distribution in the microchannel was analyzed. Various cooling strategies for the SiP were compared. When metal pillar arrays with a simple square-shaped microchannel were embedded in the substrate, the most efficient cooling was achieved under a hybrid cooling mechanism including high-efficiency heat conduction and liquid convection.