We use Amtech 4300 and clean with DI water. We have not had problems with cleaned boards and we could not induce problems on cleaned boards. While classified as L0, which might suggest that it could be used as a "no-clean", we have found that it is not suitable for us as a "no-clean" flux for rework applications in our customers service environment. 1. In its green state we were able to grow dendrites on test boards very easily. We were able to grow dendrites in the residue from the wire core solder. After seeing reflow temperatures we could not grow dendrites. So, as a rework flux there are some issues. 2. In humid environments, during cold tests where the boards are subject to frost, we found the residue became corrosive and it was again easy to grow dendrites in the residue. This is not an IPC test, I don't think there are any makers of flux that would suggest the flux residue be exposed to a condensing environment. So, is it real? It depends. It is not SMQ-92J. We found the residue of this material to be much more stable in our tests. Then there is the paste performance itself. 92J is really nice stuff on the one hand, on the other we were not as happy with their Pb-Free materials. Maybe they are getting better formulas. We have been very happy with LF-4300 paste performance and consistency. The upside on our line is one flux and one cleaning process for everything. The downside is the residues do not behave like rosin based flux residue. If they did, they would not wash off very easily would they? -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Robert Kondner Sent: Wednesday, January 21, 2009 3:04 PM To: [log in to unmask] Subject: [TN] No Clean that can be removed? Hi, For the no clean fluxes that are removed with a saponifier, can you name a couple or point me in the right direction? I found that some no cleans had a wider temperature/time process window than any of the OA fluxes but we never found anything that cleans Alpha 6100. Through hole and rework was forcing up to clean (water based) and washing the no cleans cause problems. The Alpha 6100 was a no clean and a stenciled board could sit for a few days without a complete dry out of the paste. But the 6100 residue DOES NOT CLEAN OFF in anything I found. I would love to find a no clean with a wide temp window and no dry out, like the Alpha 6100, but is also easy to remove. My previous understanding was all water soluble fluxes were variations on OA flux which require cleaning. When I saw that 4300 I was very surprised. Is it for real? Thanks, Bob Kondner -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Stadem, Richard D. Sent: Wednesday, January 21, 2009 2:47 PM To: [log in to unmask] Subject: Re: [TN] Strange Mask Appearance There are many no-clean residues that are easily cleaned in a good machine wash process with a saponifier added. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Kane, Joseph E (US SSA) Sent: Wednesday, January 21, 2009 1:42 PM To: [log in to unmask] Subject: Re: [TN] Strange Mask Appearance Steve: How can a no-clean flux be water-washable? If you leave residue on there, any moisture encountered in service would attack it, dissolving and spreading ionic contaminants, and causing corrosion, shorts, lifting of coating. And if it's something that you must clean anyway, why not use something more active, with a wider process window? Or what am I missing? -Joe -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory Sent: Wednesday, January 21, 2009 11:04 AM To: [log in to unmask] Subject: Re: [TN] Strange Mask Appearance Hi Bill! Yes, I would like your photos, thank-you very much. To respond to Tan Geok Ang, the flux we used for the rework is Amtech 4300, a solvent-based (ethanol), water washable no-clean. I know the picture looks like the area around the screw heads is delaminated, but it is not. The copper is relieved around the holes for the hardware in the inner planes and that may contribute to the appearance that there's delamination. Here's a photo of the same exact place on the same exact board after doing nothing but heating the PCB up to 125 C. as I described in my earlier post. http://stevezeva.homestead.com/files/Mask_Discoloration_After_Heating.jp g And the "before" photo: http://stevezeva.homestead.com/files/Mask_Discoloration.jpg Pretty dramatic change huh? Steve -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of [log in to unmask] Sent: Tuesday, January 20, 2009 1:59 PM To: [log in to unmask] Subject: Re: [TN] Strange Mask Appearance Steve- I'm probably the culprit that put that report on TN long ago- and again recently. Liquid solder masks often use fumed silica as filler/thickener to keep it in place. This is often sold under the Cab-O-Sil tradename. Aggressive cleaning agents can dissolve off part of the under or un cured solder mask polymer, exposing the while silica filler. When you heat the undercured mask, it will soften and allow the filler to sink down into the polymer, so the solder mask all looks green again. Re the curing from wave solder, this may not work if you are working with a UV cured mask. That's why it is important to monitor the output of UV lamps, which not all shops do, thinking that UV lamps behave the same as incandescent lamps- which they don't. Yes, the heat gun is a very inexpensive $0.05 test, quick, easy and requires no instrumentation. (Steve- I have some photos of the differences between one, two and three passes under UV lamps to show the difference if you'd like them. If so, pls give me a mailing address.) Bill Kenyon Global Centre Consulting 3336 Birmingham Drive Fort Collins, CO 80526 Tel: 970.207.9586 Cell: 970.980.6373 **************A Good Credit Score is 700 or Above. See yours in just 2 easy steps! (http://pr.atwola.com/promoclk/100000075x1215855013x1201028747/aol?redir =http://www.freecreditreport.com/pm/default.aspx?sc=668072%26hmpgID=62%2 6bcd=De cemailfooterNO62) --------------------------------------------------- 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 -----------------------------------------------------