Establishment of Production Cleanliness Criteria and Processes for Printed Wiring Boards and Assemblies

摘要

The Phase I Final Technical Report (FTR) (24 April 1978 through 26 April 1979) of the program suggested that a systems approach be used to solve the problem of contamination on printed wiring (PW). The solution was to design, assemble, and integrate a system giving a detailed profile of practically all of the ionic contaminant species. Profiling a species means detecting it (qualitative) and measuring its concentration (quantitative). The system was to consist of various pieces of analytical instrumentation suitable for profiling individual species and a minicomputer. The Minicomputer's purpose was for final analysis of the results, overall systems control of the analytical instrumentation, and final report generation. The two most promising methods of profiling contaminants on PW were direct surface analysis techniques and solvent extraction/analysis techniques. An experiment was performed to decide the better of the two extraction/analysis techniques were better. Thus the contaminant profiling (C/P) system was assembled and built using solvent extraction/analysis instrumentation coupled to a minicomputer. The main components of the C/P system are the: (1) Inductively-coupled plasma emission spectrophotometer/graphite furnace atomic absorption spectrophotometer; (2) Ion chromatograph; (3) Minicomputer and computing integrator unit; (4) Extraction tank/pumping unit; (5) Water purification unit. As a continuation of the present program, it is recommended this system be used to build a data base for printed wiring contamination.