Test Vehicles in Surface Insulation Resistance Testing Available to Purchase

Surface insulation resistance (SIR) testing is used in a number of ways to characterise residues or determine the effect of residues on the performance of printed wiring boards (PWBs) and assemblies (PWAs). Stated simply, SIR testing is the measurement of leakage currents on or in a substrate, usually during exposure to elevated temperature and humidity conditions, for a varying amount of exposure time. An examination of the resistance trends over time, and occurrences of metal migration and/or corrosion, can determine the potential threats of compatibility problems with circuit card assembly materials. This paper examines how SIR testing is used in various areas, with an emphasis on the design of the SIR test vehicle. With the advent of ANSI‐J‐STD‐001B, more companies will need to design their own test vehicle for process qualification.