Anyone familiar with HAST (Highly Accelerated Stress Test)?

[Murphys Law]

Hi guys,
Im not into reliability so this may be a very very basic question. If you are familiar with the Temperature&Humidity Oven/Chamber, how do you use it to gather failure times? IF for example I have a cycle set to 600 hours, do i have to break the cycle at regular intervals to check if a sample failed and then continue the cycle until 600 is met?

Regards,
Reynald

Reynald - from an electronics point of view, equivalent 85% RH reliability tests would be 1000 hr @ 85C = 268 hrs@ 110C = 96 hours @ 130C. Autoclave @ 121C for 96 hours could also be used but this is done at 2 atmospheres and may destroy your item under study.

You can de-rate this data to lifetime but you'd need to know your end application and moisture conditions but have some model of what you are looking for on your technology.

In electronics reliability, we would apply a "Physics of failure" based on expected fail mechanisms (For example corrosion of copper/Aluminum in presence of chlorine) where we have libraries of activation energies for different failure modes. Knowing you rel tests, end use conditions and expected fail mechs, you can then calculate an Acceleration factor (AF). Multiple the AF x # hours you ran your tests for and that gives you an estimate of lifetime.

If you were doing 600 hrs, 85/85 on a semiconductor component , it would roughly equivalent to 5-7 years consumer usage depending on temperature that the thing is running at.

Btw: It would help, if you clarified what type of product you were assessing. 600 hrs is long time if it is a quality control.