An integrated tailoring model for thermal cycling tests of spacecraft electronics

Thermal tests of electronic units are critically important for the reliability validation and performance demonstration of spacecraft hardware. A tailoring equation like that provided by MIL-STD-1540s is necessary for the testing condition planning of these thermal tests, however, the tailoring equation provided by MIL-STD-1540s is mainly based on the fatigue data of solders. In this paper, a new test condition tailoring equation is proposed by introducing an integrated evaluating method for the fatigue acceleration exponent. The different thermo-mechanical fatigue mechanisms and different subsystem characteristics have been considered and discussed in the deducing of this new equation. The test precipitation efficiency (PE) of the new tailoring law has been analyzed and compared with that from the MIL-STD-1540 tailoring equations. The results are encouraging and reasonable.