Plastic Part Die adhesion with Ag epoxy die attach

Guest

After a series of 40 + parts have undergone over a hundred hours of HAST at temperatures above 100°C, 85%RH and 100 temp shocks at the published extreems, and then successfully passed electricals per the vendor's published data sheet, is there any merit in performing bond pull integrity and die shear tesats

If one or two fail, then recovered after bake-out, is the lot good or bad

Guest

bill,

is this a new product qual? do you still have extra unstressed samples to do these tests on? i don't think the data will be useful if conducted on the stressed parts without baseline data from unstressed ones. there's merit in doing these tests on unstressed samples because the baseline data may prove useful as reference in future problems.

re your 2nd question, there are valid and critical fmechs accelerated by the bias of HAST that can recover with bake, such as mobile ionic contam. you need to have FA done on the 2 rejects. if the failure is retriggered by bias (you can do burn-in), then the problem may be real and can not be simply dismissed. if you can't retrigger the failure in any way and there are no anomalies in the rejects, then perhaps there's no real issue.

good luck!

rel engr