Title :
Environmental advantages of the semi-aqueous cleaning process
Author :
Dishart, Kenneth T.
Author_Institution :
E. I. du Pont de Nemours & Co. Inc., Wilmington, DE, USA
Abstract :
It is pointed out that the semi-aqueous process has advanced significantly since its initial introduction a few years ago. Better cleaning agent formulations have been developed and have proven to be more effective cleaners than the CFC-113 based materials they were designed to replace. New equipment designs are appearing that take maximum advantage of these new cleaning agents, to improve both cleaning performance and the ecology of the process. Because of formulation flexibility provided by the semi-aqueous process, advanced materials with improved features have been introduced. The most significant of these is higher flash point blends. Materials with higher flash points can be heated to provide better, faster cleaning, allow more material to be stored and used per fire regulations, further reduce already low evaporative losses, and allow more latitude in equipment designs. Formulation improvements have also enhanced the cleaning agent´s ability to more completely separate from rinse water, critical to supporting development of closed loop, water recycling systems. Semi-aqueous equipment design factors are now better understood, leading to the introduction of new equipment that enhances the cleaning performance and ecology of the process. Steady state control of the solvent stage reduces process variability and significantly reduces bath monitoring and maintenance
Keywords :
assembling; environmental engineering; printed circuit manufacture; surface mount technology; surface treatment; CFC-113 based materials; advanced materials; bath monitoring; cleaning agents; closed loop system; equipment designs; evaporative losses; fire regulations; flash point blends; maintenance; process ecology; semi-aqueous cleaning process; surface mount assemblies; water recycling systems; Benchmark testing; Cleaning; Environmental factors; Helium; Hydrocarbons; Process design; Soil; Solvents; Wastewater treatment; Water conservation;
Conference_Titel :
Electronics and the Environment, 1993., Proceedings of the 1993 IEEE International Symposium on
Conference_Location :
Arlington, VA
Print_ISBN :
0-7803-0829-8
DOI :
10.1109/ISEE.1993.302844