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摘要

"Characterization, Prevention and Removal of Paniculate Matter on Printed Circuit Boards" Abstract: Particulate matter contamination is known to become wet and therefore ionically conductive and corrosive if the humidity in the environment rises above the deliquescence relative humidity (DRH) of the paniculate matter. In wet conditions, paniculate matter can electrically bridge closely spaced features on printed circuit boards, leading to their electrical failure. Failures attributed to paniculate matter have even been observed in data centers where the gaseous contamination levels are low enough to meet the ANSI/ ISA-71.04-2013 G1 severity level. The combination of miniaturization of electronic components, the reduction of feature spaces on PCBs and the loosening of the data center temperature and humidity envelope to save energy are making electronic hardware more prone to failure due to paniculate matter. The characterization objective was to develop and describe a practical, routine means of measuring the DRH of minute quantities of paniculate matter (1mg or less) found on PCBs. Data center particle filtration schemes and means of removing paniculate matter from PCBs are also presented.