Title :
Observation of chip solder degradation by electrical measurements during power cycling
Author :
Hartmann, Samuel ; Bayer, Martin ; Schneider, Daniel ; Feller, Lydia
Author_Institution :
Semicond., ABB Switzerland Ltd., Lenzburg, Switzerland
Abstract :
IGBT power modules used in traction applications undergo large load variations. Thermo-mechanically induced stress then leads to material fatigue which limits the module´s lifetime. In this paper a method is presented for non-destructively quantifying the chip solder degradation during a power cycling experiment. The method is based on measuring the cooling rate after turn-off. A 20% increase in the chip solder thermal resistance has been measured after 1´800´000 cycles from 73°C to 127°C junction temperature. The solder degradation is also analysed using X-ray inspection and scanning acoustic microscopy. Based on these images and the simulated stress profile in the solder, two failure mechanisms have been identified.
Keywords :
cooling; failure analysis; inspection; insulated gate bipolar transistors; modules; scanning electron microscopy; semiconductor device reliability; solders; thermal resistance; IGBT power modules; X-ray inspection; chip solder degradation; chip solder thermal resistance; cooling rate; electrical measurements; failure mechanism; material fatigue; power cycling; scanning acoustic microscopy; temperature 73 degC to 127 degC; thermomechanical induced stress; Degradation; Insulated gate bipolar transistors; Multichip modules; Power measurement; Semiconductor device measurement; Temperature measurement; Thermal degradation;
Conference_Titel :
Integrated Power Electronics Systems (CIPS), 2010 6th International Conference on
Conference_Location :
Nuremberg
Print_ISBN :
978-1-61284-814-3