Continuous developments and growing requirements in the field of e-mobility are increasingly bringing technical cleanliness into focus when it comes to assessing the reliability of electrical systems. In the past, the requirements for electronic PCBs with regard to Technical Cleanliness focused on the specification of the number and size of metallic particles. There is a move away from specifying sizes and quantities towards risk assessments of all particles, as non-metallic particles and fibres can become conductive under higher stresses and humidity.
One component of a cleanliness concept, which must include the risk assessment of particles, is the analysis of the breakdown voltage or the so-called wetting voltage analysis.
By means of this evaluation, the critical voltage at which particles become conductive can be determined. In addition to the voltage, the humidity and temperature can also be varied and thus the dielectric strength of the particles can be tested with regard to target/ actual requirements based on
the conditions of use. The article describes the procedure for wetting voltage analysis based on the ZVEI guidelines on component cleanliness and presents a case from practice.