How is temperature cycle testing different from thermal shock testing?
Temperature cycle and thermal shock testing are expansion/contraction tests, which induce package stress due to CTE mismatch between package materials. Temperature cycle testing is done in air, whereas thermal shock testing is done in a fluorocarbon fluid. Failures, such as delamination, cracking, and solder fatigue may result from temperature cycle testing and thermal shock testing. Since thermal shock testing is more severe, failure rates are about twice as high as temperature cycle. Three temperature cycle conditions including TC-A (-55°C to 85°C), TC-B (-55°C to 125°C), and TC-C (-65°C to 150°C) are done in air. Typical cycles include 500, 1000, 1500, or 2000. The typical range for thermal shock testing is from -55°C to 125°C.
