Cg. Schmidt et al., THERMAL FATIGUE BEHAVIOR OF J-LEAD SOLDER JOINTS, IEEE transactions on components, packaging, and manufacturing technology. Part A, 18(3), 1995, pp. 611-617
Thermal cycling environments were applied to test specimens with J-lea
d eutectic Sn-Pb solder joints to assess the effect of lead and packag
e material selection, Metallographic examination and finite element an
alysis were used to evaluate the effect of thermal cycling environment
s on solder joints, Matching the coefficient of thermal expansion (CTE
) of the lead and solder was found to be crucial to reducing thermal c
ycling damage for the J-lead solder joints examined, Matching the CTE
of the package and the board was substantially less important. The num
ber of thermal cycles to nucleate cracks in the J-lead solder joints c
orrelated reasonably well with the number of cycles to produce a 50% d
rop in the load range in isothermal strain controlled mechanical fatig
ue tests on Sn/Pb solder.