Cleaning Alternatives for the 1990s

In August 1987, the EPA held a conference in Washington DC with consultants and users from the electronics industry to determine the feasibility of practical cleaning alternatives to reduce emissions of chlorofluorocarbon solvents which are considered to be a major contributor to the ozone problem in the stratosphere the world over. This paper presents a short resume of these goals and how they will affect cleaning in the electronics industry. Electronic design and packaging are the first steps in the soldering and cleaning processes. Selection of components compatible with alternative cleaning methods as well as process changes to permit low solids fluxes in some cases where cleaning can be eliminated will be discussed. ‘High containment’ in‐line solvent cleaning systems which reduce emissions are likely to become the new standard for the industry. Machines will become longer in order to include internal drying stages, instead of allowing a board with residual solvent trapped under components to evaporate after it leaves the machine prior to electronic test. Alternative solvents will become available. Designers of components and assemblies will respecify their designs to permit water cleaning, even for surface mount assemblies.