Thermomechanical lifetime models
Thermomechanical durability of lead-free electronic assemblies

Accelerated thermal cycling tests are used to measure the number of cycles to failure for different types of electronic assemblies. A large number of identical configurations (i.e., same component, same PCB, same solder, and same thermal cycling conditions) must be tested in order to perform statistical post-processing of the experimental results in terms of thermomechanical lifetime. The IPC-9701 standard, for example, recommends a sample size of 32.