Effect of bonding temperature on shear strength of joints using micro-sized Ag particles for high temperature packaging technology

As a die attach process for power modules, we focus on a sintering process using metal particles, which can be operated at a low temperature. However, some drawbacks of this technology still remain. Recently, the bonding process using the micro-sized Ag particle paste has been studied for joint reliability and cost-effectiveness, but it is limited in terms of high applied pressure or relatively low joint strength. In this study, a low pressure of 0.4 MPa was applied during bonding by using micro-sized Ag particles for various bonding temperatures. The micro-sized Ag paste used in this study was composed of chestnut-burr-like and spherical particles with micro-size. Under low applied pressure, the joint with a high shear strength over 50 MPa was achieved when the bonding temperature and time were 260°C and 600 s, respectively. The microstructure, especially the Ag sintered area ratio, was closely related to the shear strength of the joints.