From: NAME: WILLIAM G KENYON FUNC: Chemicals/Electronics TEL: 302-652-4272 <KENYONWG@A1@ESVAX> To: NAME: [log in to unmask] <"[log in to unmask]"@ESDS01@MRGATE@ESVAX> There are many acceptable cleaners for RMA flux available today that have documented use success. By class by time of introduction: HCFC: The only member of this class that is approved by SNAP is HCFC-225. The blends and azeotropes are also accepted. These are in use for RMA flux removal in high rel. (military) applications. Since the allowed workplace levels are much lower than CFC-113 or TCA type products, retrofitted equipment is highly recommended. Such equipment is extremely efficient. HFC: The first approved member of this class was 43-10. Similarly, blends and azeotropes are also accepted. New members of this class are benzotrifluoride and octafluorocyclopentane (see proceedings of Oct. CFC Conf.). HFE: The first approved member of this class was 7100. Similarly, blends and azeotropes are also accepted. In addition, a co-solvent process using HFE and high boiling organic solvent in the first tank of a vapor defluxer was described at Nepcon West Feb. 96 for the replacement of HCFC-141b for RMA flux removal in a high reliability application. The workplace exposure level of HFEs tend to be high enough (about 2x TCA) so they can be used in modern vapor defluxers without retrofitting. This is a great advantage to small to medium size companies. Alcohol: 2-propanol (IPA) with a cyclohexane/IPA first wash has been effective for RMA flux removal. Explosion/flame proof equipment, while required, is readily available from several sources in a variety of sizes. n-Propyl Bromide: This is a new material, not yet formally SNAP approved, which has the potential to be an effective TCA replacement. Available from several sources, a comprehensive paper was presented at the CFC Conf., Oct.96. Aqueous/Saponifier: Effective removal of RMA flux by saponifier has been around since 1974. Now both the traditional organic and the new inorganic saponifiers are available. However, if solvent was the previous process, then new equipment will be needed, as well as training in handling an aqueous waste stream properly. Semi-Aqueous: This was the break-through technology that showed that surface mount could be cleaned without CFC-113. Both terpene-based and hydrocarbon-based versions are available. New equipment was needed to implement this process, which is used world wide. A new variant of the process is to use a 5% water emulsion of the semi-aqueous cleaning agent as the wash step, followed by a water rinse and dry. This simplified the machine design, eliminated any flammability concern with the organic solvent, greatly minimized the waste stream and thus dramatically cut operating costs. In addition, there are many niche products, but this summarizes the mainstream product classes that are represented in the United Nations Environment Programme (UNEP) Solvents and Cleaning Agents Technical Options Committee (TOC) report. --Bill Kenyon Global Centre for Process Change, Inc. 302-652-4272/-5701 Tel/Fax US Member, UNEP TOC. *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************