For Production Phase Testing

The results of testing in the Design Phase are used to improve the product design in order to achieve improved reliability and robustness. However, unreliability can still be caused by poor component quality, manufacturing defects (eg. dry solder joints), or worst-case tolerance combinations, and these can vary from batch to batch. You therefore need effective methods of screening out these problem areas on a 100% basis to achieve the best possible product reliability. This is the function of Burn-In, Stress Screening and HASS.