Insulation Degradation and Bias Acceleration Effect Study under THB Test

It is well known that temperature humidity bias (THB) test is widely used to evaluate the moisture resistance of non-hermetic packages in semiconductor industry. The high humidity environment, high temperature and bias will reveal potential defects of package material and potential design problem that is hard to be detected at normal condition. In tins paper, a double daisy chain structure substrate was designed to make the subsequent measurement more convenient. The insulation property degradation due to THB test was evaluated. The insulation property of dielectric material would get degradation with THB test time. But even the degraded resistance after 1100 h THB test was still high enough to prevent dielectric failure occurring internal to the substrate. The acceleration effect of bias on THB test was studied. Increasing bias would greatly accelerate the THB test and shorten the test time. The acceleration factor of different bias was analyzed.