In J-STD-001,it says the fluxes must be compatible. Have your CM show you data from both Paste/Flux manufacture that their products are OK to be used with each other. > > James Cagle > Tyco Printed Circuit Group-Hayward Division > > email: [log in to unmask] > -----Original Message----- From: Dave Hillman [mailto:[log in to unmask]] Sent: Tuesday, March 11, 2003 7:45 AM To: [log in to unmask] Subject: Re: [TN] Mixing fluxes - documentation vacuum Hi John! Take a look in the IPC-HDBK-001, section 7.2.1 flux application, last paragraph. There is a cautionary statement (similar to the JSTD-001 statement Guy referenced) about the mixing of fluxes and the potential hazard of added liquid flux as a soldering aid. Dave Hillman Rockwell Collins [log in to unmask] "Vivari, John" <[log in to unmask] To: [log in to unmask] COM> cc: Sent by: TechNet Subject: [TN] Mixing fluxes - documentation vacuum <[log in to unmask]> 03/11/2003 08:10 AM Please respond to "TechNet E-Mail Forum."; Please respond to "Vivari, John" Dear TechNetters, A customer of ours came to us with a request for a reference to an IPC document or other industry standard that explicitly states the hazards of mixing flux types on an assembly. He asked for this because his contract manufacturer built a set of boards using a No-clean solder paste and reworked some BGAs with a water soluble solder paste. The contract manufacture states that he cannot find a standard "anywhere" that says the flux types should not be mixed or that there will be any long term reliability issues. I know this seems naive but that is their position. We have searched our library of specifications, books, and industry periodicals and have come up empty except for vague statements about having to clean between soldering operations for certain classes of product without explaining why and a reference in Ning-Cheng Lee's new book cautioning against combining incompatible fluxes between reflow and wave soldering. We are well versed in the hazards of mixing our own fluxes (never mind others) but have never been asked to provide "industry standard documentation" before (as opposed to a letter of explanation). Can anyone point to a reference that we have missed? Hopefully yours, John Vivari Technical Service Engineer EFD Inc. [log in to unmask] www.efdsolder.com Ph: 401-333-3800 Fx: 401-333-4954 --------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------