Thermal Shock Testing
Thermal shock testing is used to accelerate failure modes caused by very rapid changes in temperature. The two types of IC thermal shock typically utilized are liquid-to-liquid and air-to-air.
Liquid-to-liquid thermal shock testing is the most severe because of its extremely rapid induced thermal rate of change.
Air-to-air thermal shock testing is used for parts that cannot be immersed in liquid or when slower rates of change are appropriate.
The difference between the two processes is that liquid-to-liquid testing incorporates heating/cooling by conduction, whereas the air-to-air testing modifies the temperature cycle by convection, a considerably slower heat exchange process. Transition times (hot-cold and cold-hot) for both processes are typically the same, usually less than 10 seconds. The IC thermal shock test conditions for liquid-to-liquid thermal shock of integrated circuits normally specify 15 cycles and a minimum dwell of 2 minutes.
MIL-STD-883 specifies three temperature ranges for Thermal Shock: 0°C to 100°C, -55°C to 125°C, or –65°C to 150°C.
Telcordia GR 468 stipulates 0°C to 100°C, which can be performed in an antifreeze solution. The two higher ranges require the use of a perfluorocarbon fluid.
Silicon Cert Laboratories uses Galden D02-DS, a proprietary solution which has a useful range of -65°C to +150°C, in the cold and hot baths, respectively. The available temperature range for air-to-air thermal shock testing can be as high as -65°C to +200°C.
Test Specifications / Standards
- MIL-STD-750, Method 1056
- MIL-STD-883, Method 1011
- MIL-STD-202, Method 107