Study on the Falling Off Position and Heat Shift of Bonding Wire Based on Temperature Distribution Coefficient

When the bonding wire of IGBT module is aged, most traditional researches only consider the change rule of the electrothermal parameters caused by the number of dropped bonding wires, ignoring the influence caused by the difference of the distribution of the dropped bonding wires. Based on the temperature distribution coefficient k, the heat source offset caused by the bond wire falling off position is analyzed in this paper. Firstly, the temperature distribution coefficient k in the healthy state is determined by capturing the temperature at the bottom, middle and edge of the chip in a fixed position with a fiber grating sensor. Then, the FEM is used to analyze the heat source offset caused by the different number and location of bond wire falling off, and explore the law of temperature distribution coefficient k and heat source offset. Finally, an experimental platform is set up to verify the rule of heat source offset and temperature distribution coefficient k, and the specific bond wire falling off position is determined according to the values and changes of temperature distribution coefficient k on both sides of IGBT module.