The reliability of wire-bond IGBT modules is limited by the thermal and mechanical fatigue of the inter-bond line connections.
Han Ryong Hwan, a researcher at the Faculty of Electronics, has simulated thermo-mechanical stress distribution in solder joints and wire joints using the ANSYS with an attempt to define a rational linear bond shape for minimum thermo-mechanical stress.
He paid special attention to comparing the stresses in the flip-chip and the wire-bonding interconnect for various wire-bonding types of samples at constant temperature.
The results show that the thermal stress varies with the bending shape of the metal wire in the solders and connecting wires, and the thermal stress decreases with the increase in the number of bending.
You can find the details in his paper “Analysis Of Geometric Effects On The Thermo-Mechanical Stress In Al Bond Wire Interconnects In The Wire-bond IGBT Module” in “Recent Patents On Engineering” (SCI).