Rh. Richman et al., INVESTIGATION OF HIGH-CONCENTRATION PHOTOVOLTAIC CELL PACKAGES AFTER 3 YEARS FIELD SERVICE, Solar energy materials and solar cells, 30(3), 1993, pp. 263-276
As part of a controlled, step-wise development program, silicon cells
from an early production run were assembled into packages and installe
d in a prototype electrical module. After three years field service, t
he module was disassembled and the cell packages were examined in deta
il. Although all 48 cell packages were still functional, significant c
racking was discovered in the solder layers between ceramic stand-offs
and copper heat-spreaders. A simplified analysis of thermal fatigue a
s a cyclic creep process predicts useful lives of about twelve years f
or cell packages of this configuration and solder joint thickness.