Edge tail length effect on reliability of DBC substrates under thermal cycling.

The article presents a study which aims to study thermal-cracking phenomenology to determine the suitability and reliability of direct-bond-copper (DBC) substrates for high-temperature packaging under thermal cycling. Study used a finite element method with the copper's Chaboche model to analyze the distribution of thermal plastic strain at the edge of DBC substrates. Thermal analyses which involve different lengths of edge tail indicate the impact of the DBC substrate geometry in DBC's susceptibility to cracking. Study reveals the interface cracking at the bonded copper's short edge which is caused by thermal plastic strain's accumulation near short edge.