Graphite Heat Spreader Embedded in a PCB Package for Improved SiC Die RthJC

This paper presents a printed circuit board (PCB)-based packaging with a heat spreading feature suitable for wide band gap devices and high-power loss density requirements. Embedding of power semiconductor devices inside a printed circuit board stack is a promising solution to reduce circuit parasitics, simplify device packaging, and reduce cost. However, the reduction in chip size enabled by wide-bandgap (WBG) semiconductors, together with the poor thermal conductivity of the insulating layers of PCBs present some challenges compared with direct die solder on thick conductive substrate. In this paper, a graphite heat spreader technique designed to be compatible with PCB embedding technology is demonstrated. A specific graphite spreading stack is fabricated and compared with a reference sample. At last, through simulation and experimental analysis, the electrical and thermal behavior of the different samples are evaluated.