Ted, Our company has done a little compatibility testing between previously approved fluxes and never found a failure. Note, I mentioned that the fluxes were previously approved. By this I mean that they have passed the chloride ion, copper mirror, SIR and electromigration requirements of Bellcore GR-78-CORE. In addition the latter was done with stripes of various solder masks across the coupons as we have found some mask/flux incompatibilities. This flux/mask testing we do for all chemicals that are going to come in contact with the bare PCB or the completed PCBA. However, as far as doing a complete matrix of all fluxes with every board vendor source of a particular mask or a matrix of all flux combinations, we wouldn't even try that nightmare - too many combinations. For SIR the Bellcore test is 96 hours and I think the IPC test is 7 days and the Bellcore electromigration test is 500 hours (~4 weeks). An 8 week SIR test? I am not familiar with this one. My store of Circuit Assembly mags does not stretch back to 1992. regards, Bev Christian Materials Engineering Lab Carrier Solutions Nortel Networks 613-967-5407 > -----Original Message----- > From: Ted Labowski [SMTP:[log in to unmask]] > Sent: Tuesday, March 02, 1999 9:45 AM > To: [log in to unmask] > Subject: [TN] No Clean Flux Compatability > > My company is making a slow transition to No Clean chemistry in our SMT, > Wave, and Post Wave operations. > > We are taking a systematic approach and thought we were on a smooth > path until I ran across a June 1992 article published in Circuit > Assembly and authored by several Engineers at the Foxboro Company > (Foxboro, MA). > > The article was written specifically about No Clean materials and it > warns about "incompatibilities between similar solder flux products > supplied by different vendors." The conclusion is rather frightening > "The potential for intermittent and ultimately catastrophic failure of a > circuit over time due to flux incompatibility is cause for serious > concern." > > I have contacted several industry experts and all downplay the > significance of compatibility issues, although none have performed > independent testing to qualify their "opinions". > > Does anyone have any first hand experience with No Clean flux > incompatibilities? Additionally, is there any material published on > this subject other than the one I ran across? > > Barring any new information, I am prepared to undertake a regimen of > testing which will verify the compatibility of the No Clean materials > which are currently approved by MPI. The testing will be similar to > that performed in the Foxboro article ( SIR using IPC-B-25 coupons, 40 > degrees C/95% RH, 30 V bias, measured incrementally during the 8 week > cycle). > > > Ted Labowski > Vice President - Quality > Microboard Processing, Inc. > > Email : [log in to unmask] > > ################################################################ > 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's web site (http://www.ipc.org) "On-Line Services" > section for additional information. > For technical support contact Hugo Scaramuzza at [log in to unmask] or > 847-509-9700 ext.312 > ################################################################ ################################################################ 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################