Crack initiations induced by stress concentration in semiconductor chips jointed with high temperature bonding materials has
been a critical problem to operate above 200℃. To solve the problem, an insertion of Al interlayer in a Ni-Sn transient liquid phase
bonding layer（Ni-Sn TLPB/Al）has been proposed and the effect of stress reduction in the chip and enhance of high thermal
durability of joint was clarified experimentally. In this study, we investigated an effect of Al interlayer and the thickness on stress
in Si semiconductor chip（size: 5× 5 mm2, thickness: 200 mm）and strain in the Al interlayer of Ni-Sn TLPB/Al joint with DBC
（Cu/Si3N4/Cu）or DBA（Al/Si3N4/Al）plate by finite element method（FEM）analysis. The result showed that the use of 150 mm
thickness of Al interlayer enables to be lowest the stress at the edge of Si chip and strain in the Al interlayer of die-attach joint and
were expected to enhance thermal cycle reliability at high temperature operations.