Technology for the Production of Clean Electronics

This paper describes the experience gained in Sweden in connection with early phase-out of CFC-113 in the production engineering industry. It concentrates particularly on the phase-out of CFC-113 in the production of PCB assemblies, although parallel applications for cleaning of precision components, metal cleaning and : to some extent the phase-out of l,l,l-trichloroethane are also considered. The general conclusion is that, with the exception of the military electronics segment, it is straightforward for the electronics industry to find alternatives. Alternatives are also available for the cleaning of precision components and metal cleaning, with the exception of cleaning smooth surfaces of light alloys such as aluminium and magnesium There are also problems in finding an acceptable alternative for cold immersion degreasing. Environmentally, aqueous cleaning is a good alternative, and is the preferred method in this respect. Semi-aqueous cleaning has a high cleaning performance, but has some drawbacks in respect of separation and recovery of chemicals, disposal, flammability and strong odour. In terms of performance, both aqueous and semi-aqueous cleaning are good alternatives for PCB assembly, as long as water-sensitive components can be avoided and an extensive drying process be acceptedAlmost without exception, both aqueous and semiaqueous cleaning methods are being succesfully used in various companies world-wide for all types of cleaning of precision components and metal cleaning. Stains and corrosion can be avoided, although it can be difficult to avoid residues (alkali or surfactant) resulting from the cleaning operation. For some products, this is unacceptable. For both alternatives, capital investment cost is high for high-volume production processes.