Environmental Protocol
Reliability testing procedures use high temperature and humidity under pressure to identify latent defects in non-hermetic electronic packages. The highly accelerated stress test forces moisture into the plastic body of a component to trigger corrosion or insulation resistance failure. This method is faster than traditional steady-state temperature-humidity-bias testing, reducing the evaluation time from weeks to days.
Failure Acceleration
Water vapor penetrates the interfaces between the lead frame and the molding compound when the pressure inside the test chamber exceeds the ambient pressure. In a highly accelerated stress test, the combination of heat and voltage bias accelerates the migration of ions, leading to short circuits or open paths. Manufacturers use this data to qualify new materials and manufacturing processes before volume production begins.
Industry Adoption
Qualification standards for semiconductors rely on these results to ensure that devices can withstand harsh operating conditions over many years. Because the highly accelerated stress test is more aggressive than other methods, it reveals design weaknesses that might not appear in standard environmental testing. Engineers analyze the failed units to determine if the cause was a material impurity or a process variation.
This testing provides a clear indication of the long-term moisture resistance of the assembly. Results from these tests guide the selection of protective coatings.
