Title :
Thermosonic ball bonding: friction model based on integrated microsensor measurements
Author :
Schwizer, Jürg ; Mayer, Michael ; Bolliger, Daniel ; Paul, Oliver ; Baltes, Henry
Author_Institution :
Lab. for Phys. Electron., Eidgenossische Tech. Hochschule, Zurich, Switzerland
Abstract :
A model of friction during thermosonic ball bonding is reported. The model is based on recent ultrasonic stress measurements during ball bonding using piezoresistive microsensors integrated below test bonding pads. At the bonding pad, the microsensor signal is a measure of the stress caused by periodic oscillation of the capillary and gold ball. The new model interprets the oscillation in terms of alternate periods of sticking and sliding during bond formation. The oscillation shape was examined using harmonic analysis and compared with electrical parameters from the ultrasound power supply. To further validate the model, test bonds were made on passivated test pads. The model was found to be consistent with the measurement data. Experiments were performed at temperatures between 35°C and 200°C
Keywords :
electric sensing devices; gold; harmonic analysis; integrated circuit measurement; lead bonding; microsensors; oscillations; passivation; piezoresistive devices; semiconductor process modelling; sliding friction; stiction; stress measurement; 35 to 200 C; Au; ball bonding; bond formation; capillary; friction model; gold ball; harmonic analysis; integrated microsensor measurements; integrated piezoresistive microsensors; measurement data; microsensor signal; model validation; oscillation shape; passivated test pads; periodic oscillation; sliding; sticking; test bonding pads; test bonds; test temperatures; thermosonic ball bonding; ultrasonic stress measurements; ultrasound power supply electrical parameters; Bonding; Friction; Gold; Microsensors; Piezoresistance; Shape; Stress measurement; Testing; Thermal stresses; Ultrasonic variables measurement;
Conference_Titel :
Electronics Manufacturing Technology Symposium, 1999. Twenty-Fourth IEEE/CPMT
Conference_Location :
Austin, TX
Print_ISBN :
0-7803-5502-4
DOI :
10.1109/IEMT.1999.804803
