Relationship between transient thermal impedance and shear strength of pressureless sintered silver as die attachment for power devices

In our previous work, we had obtained “void-free” joints for large area die attachment by pressureless sintering of nanosilver paste at low temperatures. In this paper, we studied the relationship between transient thermal impedance and shear strength of the pressureless sintered nanosilver joints and found that the relationship could be described well by an exponential equation. According to this equation, the shear strength of the insulated gate bipolar transistor device could be estimated nondestructively by measuring its transient thermal impedance using the electrical method. The transient thermal impedance measurement is suggested as an alternative method to evaluate the quality of the die attachment for power devices.