Title :
Effect of temperature on isothermal fatigue of solders
Author_Institution :
BIRL, Northwestern Univ., Evanston, IL, USA
Abstract :
The effect of temperature on isothermal fatigue of low-tin lead-based and lead-tin eutectic solders was studied at low strain ranges (0.3-1.0% total strain) in tests without and with hold time in the cycle. While temperature almost does not affect the fatigue life of eutectic solder, the fatigue life of low-tin lead-based solder is a complex function of temperature. Extrapolation of fatigue data for this solder was possible only in a 25 to 80°C temperature range using the values of apparent activation energy from 25 to 45 kJ/mol. depending on strain range, strain rate, and presence of hold time in the cycle. Variation in the values of activation energy was found to be associated with different failure modes under various testing conditions. The higher activation energy for fatigue of low-tin lead-based solder was associated with the mixed transgranular-intergranular mode of failure. Failure in grain boundaries was characterized by lower values of activation energy
Keywords :
fatigue testing; lead alloys; soldering; tin alloys; 25 to 80 C; Sn-Pb alloy solders; activation energy; effect of temperature; eutectic solders; failure modes; fatigue data extrapolation; fatigue life; hold time; isothermal fatigue of solders; low Sn Pb based solder; low strain ranges; mixed transgranular-intergranular mode of failure; presence of hold time; strain range; strain rate; temperature range; testing conditions; Capacitive sensors; Electronic packaging thermal management; Fatigue; Isothermal processes; Joining materials; Lead; Temperature distribution; Tensile strain; Testing; Tin;
Conference_Titel :
Thermal Phenomena in Electronic Systems, 1990. I-THERM II., InterSociety Conference on
Conference_Location :
Las Vegas, NV
DOI :
10.1109/ITHERM.1990.113306
