Rudolph, Most criteria for cosmetic acceptance of no-clean boards are pretty subjective. One absolute no-no is flux residue in the holes of edge connectors. Other than that, we have not really had an issue with flux residues since the early nineties. I'm not quite sure I know what you mean by a "stain", but at most we will see some residue around the PTH leads of massive parts (those with a large thermal mass), other than that we do not see much of anything. Nitrogen helps, but should not be necessary to reach this stage. I would also recommend the newer spray fluxers as opposed to wave, foam or the old drum spray fluxers. These are my personal preferences showing through. Also, I would definitely talk to your flux supplier about this issue. Perhaps he/she can give some suggestions as to your profile or perhaps you need to change fluxes. Corrosive material in no-clean fluxes!!? Ahhh, where's a tall building to jump off of? That is a very inflammatory statement (pun, unless you are talking VOC free :) ) I will start by asking the philosophical question of "what is small?" (no smart comments, please). If you are talking about ppb or maybe ppm. OK, but there shouldn't be "significant " amounts of corrosive materials in the no-clean fluxes of reputable manufacturers. If there is, we're in trouble, because we have had product out in the field with no-cleans since the late 80's. regards, Bev Christian Nortel > ---------- > From: Rudolph Yu[SMTP:[log in to unmask]] > Sent: Tuesday, September 01, 1998 3:56 PM > To: [log in to unmask] > Subject: [TN] Inspection criteria for no clean assembly? > > Currently we accept no clean assembly as long as we can not see stain > mark or powder residue on the assembly within 2 feet after the wave > soldering process. What is yours like? > Is there a need to check for contamination level on no clean assembly? > If the answer is yes, then what measurement should I test it against? > What tester in the market does serve this function? > The reason why i ask the question is because I heard that even no clean > flux does contain small amount of corrosive material, thus can affect > the product in long run. > Thank you > > ################################################################ > 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 ################################################################