> From: Doug Pauls <[log in to unmask]> > To: [log in to unmask] > Subject: Re: [TN] FAB: HASL vs. anything else -Reply -Reply > Date: Friday, January 30, 1998 10:38 AM > > In a message dated 98-01-27 09:04:21 EST, you write: > > > > > The IPC limit for contamination is 10.07 ug / sq in NaCl equiv. The 3 ug > > limit is good for no-clean, but naturally the cleaner the better. > > > > It should be pointed out that the historical 10.06 figure was for finished > assemblies, processed with high solids rosin fluxes. For bare boards, MIL- > P-55110 (or was it 28809?) had a value of 5.5 micrograms of sodium chloride > equivalence per square inch. IMHO, both are a crock. > > These limits have been so abused and applied to so many inapproprate places > that it is not funny (one of my favorite pet peeves). > > A better measure of board and cleanliness is ion chromatography (IPC-TM-650, > method 2.3.28). For this, we advise bare board cleanliness of less than 2.00 > micrograms of chloride per square inch and less than 15 micrograms of bromide > per square inch. These measures are NOT THE SAME as the ROSE measures above. > > More information on these will be available on our web page, assuming I can > get the host service to get it in place in the next week or so. (A nightmare). > > Doug Pauls > CSL > I agree with you to some extent. However, IC is an expensive test. I think 3 eq. micrograms NaCl / sq in measured by Phil Whitmer's modified ROSE test, which uses the same extraction method as the IPC IC test would be just about as good as 2 microgram Cl- /sq.inch by IC. Modified ROSE is a much cheaper test, all that is needed is isopropanol, DI water, KayPak bags, a hot water bath, a solution condutivity meter and a standardizing NaCl solution. Any PC fab. or electronics assembly shop can do it on a routine basis. ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################ ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################