Block level and package level thermal assessment for back side power delivery network.

Abstract

This paper combines an experimental and modeling approach to investigate the thermal aspects of backside power delivery network configurations. A dedicated test chip with integrated thermal heaters and sensors is used to evaluate the heat spreading through the backside metal layer. It is found that orienting the backside metal line in the direction of the temperature gradient is more effective for heat spreading. The modeling framework consists of a package level model and a block level model. Package level models were used to investigate the impact of cooling solution boundary conditions and hotspot sizes, while the unit cell block level simulations targeted the impact of local design features and material options. The package level results show the that assumptions for the power distribution have a very large impact on thermal penalty metric for the BSPDN and need to be defined for an accurate thermal analysis. The unit cell results show an improvement on the thermal performance can be achieved by combining high thermal conductivity dielectric materials with a high metal density design in the backside metal stack.