Study of equivalent thermal modeling and simulation of 2.5D/3D stacked dies module

In the paper, an equivalent modeling method is proposed to simplify thermal simulation model of 2.5D stacked dies modules. A TSV and its surrounding silicon substrate or a micro bump and its surrounding underfill will be equivalent to a single body of material. Through this method, we will not only be able to obtain thermal characteristics of each part of the stacked dies module, but also can greatly simplify the calculation amount of numerical simulation. According to this method, we obtained thermal distribution map of 2.5D/3D stacked dies module; in addition, to guide and optimize thermal management design, we analyzed the influence of several parameters on maximum junction temperature of 2.5D stacked dies as well, such as spacing among dies, thermal conductivity of TIM2 (Thermal Interface Material), ambient temperature, wind speed and so on. It was found that with the increase in spacing among dies, the maximum junction temperature of dies decreases and the maximum decreasing amplitude is 4.4°C. Secondly, impact on the maximum junction temperature of die, the ambient temperature of the cabinet is the most serious. Finally, the wind speed of the cabinet and the thermal conductivity of TIM2 (Thermal Interface Material) also have a great effect on the maximum junction temperature of die.