Considerations in the Use of Terpenes for Electronic Assembly Cleaning

Considerations in the Use of Terpenes for Electronic Assembly Cleaning 
Richard B. Flegel – Motorola Inc. (SSA Journal Volume 5 Number 3 – September 1991 pp. 27 – 31 )

Concerns over stratospheric ozone depletion and the resulting negative affects on our environment have cause considerable interest in alternatives to Chlorofluorocarbons (CFCs) as cleaning agents. One of the alternatives under evaluation by industrial users is terpene based semi-aqueous solvent. Terpenes have been used as cleaning agents for a number of years in non-electronic applications. Recent work has proven terpenes and terpene/surfactant mixtures as effective electronic assembly cleaners. This paper focuses on the materials compatibility, safety, and toxicology of terpenes for electronic assembly cleaning. The technical aspects of board cleaning are beyond the scope of this paper and have been thoroughly addressed in the literature. The use of terpene cleaners in either a batch or in-line cleaner situation involves the control of air and water emissions, fire hazards and worker exposure. Experience with the effects of terpenes on board assemblies, wiring harnesses, rinse and exhaust systems, and work place atmospheres is now being accumulated. Because terpene cleaners and cleaner systems are a major departure from the Freon 113 and 1,1,1 trichloroethane normally used for electronics cleaning, new approaches are required for the incorporation of terpenes in the electronics assembly process.