Surfbee Contamination % sting Revisited by Marta

his article covers two test methods to detect and identify surface organic contamination on bare boards or assemblies that we feel are still not sufficiently known to this industry. They are excellent inspection and corrective action tools to help solve contamination problems. The “Detection” method is simple and safe. and can be used right in the productionarea. with lirmted skilled personnel. The “Identification” method is a little more complicated. The latter is a new laboratory infrared spectrophotometer for detecting contaminants, and to develop chemicals. analysis technique to identify the specific contaminant(s). After detecting surface contamination, the analysis provides significant guidance to the process engineering and production groups for taking corrective action. The principle purpose of this article is to present a detailed iescription of the necessary materials and apparatus to perform 30th test methods. Until now. the printed circuit industry has only had a practical neans for detecting ionic contaminants. Now, for the first ime (thanks to work done by Dr. Bill Kenyon and Ron Kiaer If DuPont Laboratories), we have these new and practical nethods. Both test methods have been approved by the IPC/ANSI and he Defense Electronics Supply Center for military specificaions. They now appear in MIL-P-55110D. “Rigid Printed Miring Boards.” MIL-P-50884C. “Rigid Flex Circuits.“ PC-ML-950C. “Rigid Multilayer Boards.” and will be added to MIL-P-18809, “Printed Wiring Assemblies,’’ during the next revision.