Comparison of ionic contamination test methods to determine their ability to reliably predict performance risks

In the Electronic Manufacturing Services Industry, one of the known failure mechanisms is caused by the presence of ionic contamination. Ionic contamination leads to electrochemical migration and dendritic growth. Through the years, there have been various methods employed to verify the ionic cleanliness of electronic components, printed circuit boards and their assemblies. The accepted industry standard test is Surface Insulation Resistance, SIR, testing. Although this is recognized as the test of merit, it can take weeks to prepare the test vehicles, run the test and analyze the results. By the time this is complete, the product has shipped. If failures are found in test, it is too late to be of practical use. The industry is looking for a test which can be run quickly and is representative of the product currently in production so that decisions, and potential corrective actions can be implemented prior to shipping product to customers.