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Hydroflourocarbon Solvents In Precision Cleaning

“Hydroflourocarbon Solvents in Precision Cleaning” Proceedings of the National Electronic Packaging and Production Conference – West “94. March 1-3, 1994. 237-247.

Basu. R. S., K.P. Murphy, and E.M. Kenny-McDermott

The use of non-flammable “precision cleaning” solvents had its birth in the space age where mild, very low residue, safe solvents were required. The first solvent to meet these requirement was 1,1,2-trichloro-1,2,2-trifluoroethane better known as CFC-113. In the 1960’s the use of this solvent and various azeotropic blends found increasing applications in electronics and metal working industry. CFC-113, being mild, stable, non-flammable, remained the workhorse of the precision cleaning industry as it brought together a combination of properties found nowhere else.

With the arrival of the ozone depletion issue in the late 1970s and 1980s [1], chemical manufacturers worldwide began searching for an acceptable alternative to CFC-113. In many of its area of use, new technologies and processes were developed which were effective but the application of precision cleaning remains one of the most difficult for effective substitutes for CFC-113. The first series of volatile non-flammable solvents developed were hydrochlorofluorocarbons (HCFCs) [2]. These materials suffered one drawback in that they are low but non-zero ozone depleting. As a result these compounds can be considered as transitional substitutes.

This leads to the next generation solvents which are based on hydrofluorocarbons (HFCs). This class of compounds do not contain chlorine and therefore do not affect the ozone layer. These materials as a class are not excellent solvents but are fairly effective in various cleaning applications with additives such as alcohols, ketones, esters etc.

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