Motorola Corporation

Lawrence R Hagner

James A Wrezel

Robert C Pfahl, Jr

A distillable, non-azeotropic solvent mixture for electronic assembly cleaning in order to adequately remove solder flux and other residues traditionally removed using CFC-based azeotropes. The mixture is heated to at least the boiling point of component A but less than the boiling point of component B. Component A vaporizes (102), forming a vapor layer above the mixture (103). Condensing elements (101) near the top of the cleaning apparatus condense the vapor (102), returning it to the heated mixture (103) to be vaporized again. The assembly (104) to be cleaned is lowered through the vapor and then immersed in the mixture (103) before being positioned in the vapor (102).

Method for electrical assembly cleaning using a non-azeotropic solvent

Non-azeotropic solvent composition for cleaning and defluxing electrical

The apparatus of the present invention uses a vessel with a sump for containing a liquid (103). The vessel has one or more downward angled openings (101). A heating device (104) boils the liquid to produce a vapor and a condensing apparatus (102), in the opening or in a separate chamber, prevents any vapor from exiting the apparatus. The apparatus contains a condensable liquid having a vapor density less than that of the ambient atmosphere by producing a stably stratified interface between the condensable vapor and the ambient atmosphere. The apparatus can be used for such manufacturing processes as cleaning or coating with vapors that are less dense than air.

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Naperville, IL, United States of America

Lawrence R Hagner