Analysis of design of experiments used as a tool to implement environmentally safe cleaning process in manufacturing [hybrid ICs]

Due to concerns for the environment and due to international treaties which will soon ban the use of certain environmentally destructive cleaning solvents (Chlorofluorocarbons, 1,1,1 Trichloroethane, etc.), the typical post-solder cleaning processes used for the manufacturing of electronic components have had to be addressed. A case study of a hybrid component which utilized a cleaning process requiring change is discussed. It was determined that the best tool to evaluate alternatives was the use of design of experiments (DOE). This DOE evaluates several cleaning alternatives on a custom hybrid (passive resistor array) product. This full factorial DOE consisted of the following three variables (1) water quality, (2) lead attach flux/cleaning method, and (3) conductor ink composition of the hybrid. The primary output of the DOE was change in electrical resistance due to a humidity test (85°C/85%RH/1000hr). Based on the results of this primary output, one set of conditions was selected as the best. Additional functional testing was performed. The results of the humidity as well as the functional tests are discussed