Accelerated Life Testing of Electronic Devices by Atmospheric Particles: Why and How

Abstract

Research on atmospheric corrosion and degradation of electronic materials and assemblies is usually carried out without considering the potential effects of airborne submicron particles, most of which are potentially corrosive ionic compounds. Yet data show that, in many urban indoor environments, the mass concentration of these particles and their arrival rate at surfaces are comparable to the mass concentration and arrival rate of corrosive gases. It is shown here that experiments that ignore the effect of particles are not representative of degradation in real‐world environments. In recognition of this deficiency, an accelerated life test chamber was developed to evaluate the effect of submicron ionic particles on electronic devices, circuit boards, and other assemblies. The characteristics of the chamber include (i) 0.01–1 μm diam particles at a concentration , (ii) parallel air flow at velocities up to 35 m/min, and (iii) uniform and constant particle concentration. The average acceleration factor for particle deposition is 100.