Abstract
In this work, we introduce a novel method for in-plane thermal diffusion applied to a 3D System in Package (SiP). An evaluation device consisting of a micro-heater was fabricated on a 100 μm-thick Si substrate. A high thermal conductivity (HTC) 10 μm thick multilayer film is deposited directly on the back of the Si substrate. The hotspot temperature time response is measured by supplying a pulse power of 0.1 J in 8.5 ms to the heater. The peak temperature rise in the hotspot is confirmed to be 27% lower than that of a device without the HTC film. Furthermore, the temperature difference between the center of the hotspot and a point 1,000 µm away from the hotspot is decreased 20% by changing the pulse width of heating from 16.6 ms to 100 ms. In conclusion, the use of HTC film evens the temperature distribution over the entire substrate simultaneously and reduces the hotspot peak temperature.
