Storage life and reliability evaluation of microwave electronical product by SSADT

High storage reliability system requires the extremely high reliable assemblies over long periods of storage time. Within severe time and cost constraints, step stress accelerated degradation testing (SSADT) was utilized to evaluate storage reliability and life of microwave electronical assembly. Firstly, the assumptions of SSADT were given. On the basis of failure mode effect and criticality analysis (FMECA) and fault tree analysis (FTA) results of the microwave assembly, accelerated model was determined. Then, reliability evaluation model was generated combined with linear drift Brownian movement. By the independence increment property of linear drift Brownian movement, the maximum likelihood and regression analysis were used to evaluate the parameters of reliability model. In order to eliminate the effect of power cycle on storage reliability and life, degraded rate conversion method and converted function of linear drift Brownian movement was presented in light of GJB108-98. Engineering application validated that reasonable evaluated results could be obtained by the methodology proposed.