Thermal deformation analysis of ceramic substrate with thick Cu layer

Ceramic substrates with thick Cu layers have been developed to improve the heat radiation performance of power semiconductor packages. In this paper, we measured the thermal warpage of a substrate with thick Cu layers and found substantial thermal warpage. This warpage difers from the deformation behavior of existing ceramic substrates with thin Cu layers and increases in both the orthogonal and the parallel directions as the temperature rises. We investigated the mechanism of this thermal warpage and found that it is caused by the relationship between the rigidity of the ceramic and of the Cu. Furthermore, we showed that the thermal warpage can be estimated by stress analysis considering these mechanisms. © Japan Institute of Electronics Packaging. All rights reserved.