Heat spreading packaging solutions for hybrid bonded 3D-ICs

Direct hybrid bonding is considered as one of the most promising technologies for high performance 3D-ICs. Its face-to-face structure allows significant inter-connexion capabilities. Nonetheless, it also implies increased thermal densities that will be reflected in both die tiers due to the lack of insulating barriers. This work investigates the thermal interactions between two hybrid bonded dice for different case scenarios. A specific test vehicle comprising heaters and temperature sensors have been designed. Packaging variables such as silicon thickness, substrate thermal design or TIM conductivity and thickness are studied.