Title :
Isothermal creep of eutectic SnBi and SnAg solder and solder joints
Author :
Raeder, C.H. ; Schmeelk, G.D. ; Mitlin, D. ; Barbieri, T. ; Yang, W. ; Felton, L.F. ; Messler, R.W. ; Knorr, D.B. ; Lee, D.
Author_Institution :
Design Res. Center, Rensselaer Polytech. Inst., Troy, NY, USA
Abstract :
The isothermal tensile steady state creep rates of cast SnBi and SnAg eutectics are reported at temperatures between 20°C and 160°C, The SnBi eutectic has three regions of stress dependence with an extended power law region with stress exponent, n=3, at rates relevant to thermal fatigue. The SnAg eutectic has a simple power law stress dependence with a stress exponent between 6.7 (high temperatures) and 8.4 (low temperatures). These results are compared to room temperature creep rates of lap shear solder joints. The SnBi data correlate well. SnAg lap shear joints were significantly stronger than bulk samples. The difference is due to the amount of copper dissolved in the solder during reflow
Keywords :
bismuth alloys; creep; eutectic alloys; packaging; reflow soldering; silver alloys; thermal stress cracking; thermal stresses; tin alloys; 20 to 160 degC; SnAg; SnBi; bulk samples; eutectics; extended power law region; isothermal creep; lap shear solder joints; reflow soldering; solder joints; stress dependence; stress exponent; tensile steady state creep rates; thermal fatigue; Assembly; Capacitive sensors; Creep; Electronic packaging thermal management; Fatigue; Isothermal processes; Soldering; Temperature sensors; Thermal resistance; Thermal stresses;
Conference_Titel :
Electronics Manufacturing Technology Symposium, 1994. Low-Cost Manufacturing Technologies for Tomorrow's Global Economy. Proceedings 1994 IEMT Symposium., Sixteenth IEEE/CPMT International
Conference_Location :
La Jolla, CA
Print_ISBN :
0-7803-2037-9
DOI :
10.1109/IEMT.1994.404699
