Tailoring HALT/HASS tests

Some of significant factors that need to be taken to improve HALT/HASS tests results, are discussed. HALT was developed to test thermal step stress, rapid thermal cycling, vibration step stress, and combined thermal and vibration in commercial electronics, and it can be used to test mechanical devices and mechanical structures. The mounting location of HALT need to be chosen with proper care for simultaneous testing of multiple units. Rigid fixture on the table can reduce the energy input to the part being tested, so each unit need to have an individual fixture in case of multiple units. HASS test need to use the same equipments and testing philosophy as HALT. HALT can be used to determine the design errors by using appropriate equipments.