Generally, solder materials have been used for the mechanical joints of power devices. However, in the case of power devices operating at high temperature (>300℃), solder bonding does not make sense due to its low melting point. Recently, many researchers have paid much attention for sintered silver bonding technology. In power electronic applications, mismatches of thermal expansion (CTE) coefficient between the materials used in bonding section are inevitable. Consequently, repeated mechanical stresses induced by heat cycle lead to the deterioration of die-attach materials. Thermal cycle test requires amount of time for endurance evaluation. Our goal of this work is to find a reliability acceleration test by means of cyclic mechanical testing. Finding a correlation in degradation between cyclic mechanical test and cyclic thermal test is one of our objectives in this study.