Thermal Management and Processing Optimization for 3D Multi-layer Stacked ICs

3D ICs integration has shown significant advantage in performance enhancement and power reduction. One of the key components in 3D integration technology is to stack multi-layer thinned ICs to make a reliable electrical and mechanical connection. Thermo compression bonding (TCB) has been used to manufacture 3D ICs due to its capability to bond fine pitch micro bumps. However, it has been a challenge for TCB process to control the temperature over the bonding interfaces and it increases its complexity when multi bonding interface are bonded at once. In this paper we use integrated thermo sensor to investigate temperature gradient during TCB for multi die stacking. The real time temperature measurements are combined with finite element modeling (FEM). The calibrated model is used to explore temperature in bonding interfaces that are not accessible through measurement and enhance the understanding of heat transfer during the TCB process for multi die stacks.