A Study on the Effect of Bond Wires Lift-Off on IGBT Thermal Resistance Measurement

Bond wire lift-off will cause an increase of remaining wires’ power dissipation, which usually is ignored for healthy modules. However, only partial dissipation transfers through thermal path from junction to case, lead overestimate the whole collector emitter pole and underestimate calculated resistance using proportion temperature difference dissipation. A FEM model established show change heat flow after bond wires were removed, increases, measured decrease lift-off. It validated by experimental results open package Insulated Gate Bipolar Transistor (IGBT) modules under different current conditions. This conclusion might be helpful indicate solder fatigue comparing resistance. Using Kelvin setup measure misjudgment failure mode due ignoring paper proposed that underestimating measurement, lifetime IGBT module misjudge its state health.