Well, this Rockwell guy talks about it a lot but I don't think we have released a paper on it. We did present the view at the recent cleaning conference in Chicago. I have consistently told our people internally that alcohol sucks (technical term) as a cleaner. It gets used because it is cheap, plentiful and dries fast. Many erroneously assume that "like dissolves like" and that since isopropanol is used as a carrier solvent for rosin flux, it must also dissolve rosin flux. As others have pointed out, alcohol does not clean off the rosin salts and polymerized rosin remaining after the soldering operation, so that "like" rule does not apply. Doug Pauls Rockwell Collins Guy Ramsey <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 12/17/2008 10:47 AM Please respond to [log in to unmask] To [log in to unmask] cc Subject Re: [TN] flux and board cleaning issues I am not a chemist. But, yes alcohol dissolves rosin. But, see Brian's comments. He is absolutely right. The by products of the soldering process may not dissolve. And they can be released by a feeble attempt at cleaning. Improper cleaning can be worse than no-cleaning. Conventional wisdom says alcohol, while commonly used, is cheap but not very effective. However, Curt Alexander offered this contradictory report to the Assembly Community. http://circuitsassembly.com/cms/content/view/3851/95 It is possible to clean using the other materials mentioned earlier in this thread but it is still a process of diluting and rinsing, only much more expensive and potentially hazardous. Didn't the guys at Rockwell release a paper on this subject recently? -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Kevin Glidden Sent: Wednesday, December 17, 2008 9:17 AM To: [log in to unmask] Subject: Re: [TN] flux and board cleaning issues "Alcohol will dissolve the flux..." Is that accurate? I am under the impression that alcohol is a solvent that will assist in loosening RMA residues, but it will not dissolve them....at least that is how I understand it.... Kevin Glidden Manufacturing Engineer Luminescent Systems Inc. -----Original Message----- From: Guy Ramsey [mailto:[log in to unmask]] Sent: Tuesday, December 16, 2008 10:48 PM To: [log in to unmask] Subject: Re: [TN] flux and board cleaning issues Alcohol will dissolve the flux. Compressed air will move the mixture. One must wonder where it goes. Compressed air can be present an electric potential to the board. It may work fine . . . Or not. Your instructor was probably taught about the potential problems with this cleaning method. The brush is probably not as effective as the compressed air. Are there any ESDS devices on the board? -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Wilson, Bob Sent: Tuesday, December 16, 2008 7:12 PM To: [log in to unmask] Subject: Re: [TN] flux and board cleaning issues Rosin Mildly Activated -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of R Sedlak Sent: Tuesday, December 16, 2008 4:04 PM To: [log in to unmask] Subject: Re: [TN] flux and board cleaning issues Bob: Why not advise on the type of flux you are using. Rudy Sedlak RD Chemical Company --- On Tue, 12/16/08, Wilson, Bob <[log in to unmask]> wrote: From: Wilson, Bob <[log in to unmask]> Subject: [TN] flux and board cleaning issues To: [log in to unmask] Date: Tuesday, December 16, 2008, 3:55 PM Hi, I have a lead who is an IPC J-STD-001 certified trainer and she is very good. We are using a board assembly that has a nut plate under a high-density 26-pin DSUB. The girls were soaking the assemblies in an alcohol bath and the lead assembler said she didn't want the boards soaked in alcohol because it isn't 100% guaranteed to remove all the flux from under the connector or nut plate. She has the girls trying to get a brush under there to get the flux out. Am I nuts or have I been under the wrong impression that alcohol and compressed air is the best way to clean a fluxed board? I hate the idea of me saying something like, "But...but that's the way we've always done it!" (I don't have J-STD-001 here on the design side). Thanks a bunch. Bob Wilson --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------