An Integrated Cooling Effect Package for High Performance Computing Chips

High performance computing of big data center, cloud computing, high speed networking switch and artificial intelligence has made modern life more convenient than ever, and it also drives the continuous innovations in semiconductor technology. However, high performance computing chips often accompany with huge power and large package size which could lead to thermal and warpage issues. In order to solve both issues at the same time, an innovative integrated cooling effect package for high performance computing chips was proposed and designed in this work. This innovative package had internal liquid channels which would allow liquid to dissipate the heat efficiently and superior thermal performance was expected since there was no thermal interface material (TIM) used on both package-level and system-level. This innovative package would be more competitive and attractive in the application of space limited system such as 1U rack thanks to the extremely compact size of cooler.In order to understand and verify the thermal performance of this innovative package, a detailed package thermal model and a thermal test vehicle (TTV) with liquid cooling lid were built up and assembled. Furthermore, a liquid cooling thermal test was performed to measure the thermal resistance of junction-to-air to understand its cooling capability. The result showed that the thermal model could achieve great accuracy compared with experimental result. As liquid leakage was another important design factor to investigate, an air pressure experiment was adopted to examine the package and it’s proved that the risk of liquid leakage could be prevented with this innovative package structure. Finally, the warpage of package was evaluated and confirmed that this innovative package could have great warpage performance equally with conventional lid-type package.In pursuit of cooling capacity study, different flowrate and power values were evaluated. Evaluation indicated that the bonding material between flow channel and die played a significant role; therefore, several types of material were demonstrated. Most important of all, the thermal performance and pressure drop level in water-cooling experiments could be practical in high computing system application nowadays. Based on the experimental results, this innovative package showed a tremendous potential in the balance of thermal optimization and warpage control for high performance computing chips.