Heat dissipation improvement with diamond heat spreader on hybrid Si micro-cooler for GaN devices

A diamond heat spreader of small size has been directly attached between the chip and the hybrid Si micro-cooler for thermal performance improvement of the GaN-on-Si device. In the fabricated test vehicle, one hotspot of size 450×300μm² is used to mimic the heating area of one GaN unit. The microwave CVD diamond of high thermal conductivity was bonded through TCB process. With the diamond heat spreader attached on the reduced by 25.7% and 26.1%, respectively. Two types of diamond heat spreader of different thermal conductivities are tested and compared. High improvement of heat dissipation capability has been demonstrated.