UHAST

AcronymDefinition
UHASTUnbiased Highly Accelerated Stress Test
References in periodicals archive ?
The same failure phenomenon was observed after HAST as well as UHAST stresses, and it is most probably attributed to [Cl.sup.-] attacking the edge of Cu ball bond region.
In Au and PdCu wire bonding evaluations on 110 nm devices, we have successfully characterized the wearout reliability margins for HAST and UHAST and determined the diffusion kinetics of both wire types used in nanoscale semiconductor packaging.
PdCu ball bonds showed a slightly lower UHAST wearout hour to failure but still far exceeding the JEDEC standard of minimum 96-hour surviving hours rate.
(2) Wearout failure mechanism of HAST and UHAST stress testing belong to CuAl and AuAl IMCs interface corrosion and microcracking which induced electrical ball bond opens.