Surface insulation resistance (SIR) measuring equipment

The surface insulation resistance (SIR) is crucial for the reliability of circuits. The properties of the flux residues left on the surface after soldering are decisive in this respect as well. The Auto-SIR™ device is used to measure the surface insulation resistance. The equipment is not only suitable for detecting the danger of defects of electrochemical origin (e.g. migration) on the surface, but also for the detection of a similar phenomenon, the formation of conductive anodic filaments (CAF), which may occur inside multilayer circuit boards, between the layers. 
Although surface insulation resistance (SIR) has been used for 40 years to characterize materials, its use to predict the operational reliability of electronic circuits is a fairly recent, accurate, quantitative method.
The measurement, which characterizes the production and assembly process, is performed on a test panel under prescribed temperature and humidity conditions. If there is any deviation of the surface insulation resistance, it foretells that the long-term reliability of the product is at risk.