SN96.5/Ag3.5 RA flux Jason Gregory Manufacturing Engineer Innova Electronics (281)653-5593 (281)653-5594 fax (281)212-0844 cell [log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Joyce Koo Sent: Thursday, March 10, 2005 8:17 AM To: [log in to unmask] Subject: Re: [TN] Cleaning residues off of PCB [faked-from][mx] Jason, could you tell us the flux/paste you were using? thanks. jk -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Douglas O. Pauls Sent: Thursday, March 10, 2005 8:15 AM To: [log in to unmask] Subject: Re: [TN] Cleaning residues off of PCB [faked-from][mx] Jason, The photo makes it pretty clear that you have some residual rosin from the flux that survives exposure to both cleaning chemicals you use. You might also consider using Kyzen A4520 (10% solution) or Envirosense 816 (7% solution), both at 140F, maybe a 5 minute presoak followed by aqueous cleaning. I would suggest that you do not really need to clean at all, at least more than what you are doing now. The white residues you see are primarily cosmetic in nature. In the vast majority of cases that I have examined, white residues of this low level are not a reliability hazard, purely cosmetic. The only time I have seen the white residues as a problem was when they were waaaaaaaay thicker than what you have. Vapor degreasing and other cleaning would have removed the bad actors from the flux. Doug Pauls PS: the next time you get the urge to soak electronics in an acid, tell yourself " I don't wanna do this". Jason Gregory <jgregory@innovae lec.com> To Sent by: TechNet [log in to unmask] <[log in to unmask]> cc Subject 03/09/2005 03:50 Re: [TN] Cleaning residues off of PM PCB [faked-from][mx] Please respond to TechNet E-Mail Forum <[log in to unmask]> ; Please respond to Jason Gregory <jgregory@innovae lec.com> These PCBs were ran through same machines, same process, same alloy, same convection reflow profile, just different results between the first and second passes. Jason Gregory Manufacturing Engineer Innova Electronics (281)653-5593 (281)653-5594 fax (281)212-0844 cell [log in to unmask] -----Original Message----- From: McMullen, Kerry [mailto:[log in to unmask]] Sent: Wednesday, March 09, 2005 3:46 PM To: 'TechNet E-Mail Forum'; 'Jason Gregory' Subject: RE: [TN] Cleaning residues off of PCB [faked-from][mx] I know this is after the fact, but are the boards being pasted by the same printer? If yes, then I don't know. If not, insure they are using the same solder paste. I've seen NC being mixed with Aqueous before. (and hopefully never again!) -----Original Message----- From: Jason Gregory [mailto:[log in to unmask]] Sent: Wednesday, March 09, 2005 4:37 PM To: [log in to unmask] Subject: Re: [TN] Cleaning residues off of PCB [faked-from][mx] Sorry, Cleaning process is vapor degreaser, then terpene. The residues are not white. As far as differences between first pass and second, there were none. Both passes are cleaned in exact manner. Jason Gregory Manufacturing Engineer Innova Electronics (281)653-5593 (281)653-5594 fax (281)212-0844 cell [log in to unmask] -----Original Message----- From: Blomberg, Rainer (FL51) [mailto:[log in to unmask]] Sent: Wednesday, March 09, 2005 3:16 PM To: TechNet E-Mail Forum; Jason Gregory Subject: RE: [TN] Cleaning residues off of PCB Try Axarel 2200 from Petroferm (http://www.petroferm.com/PTF-053/clean/clean_frm.html). This is what we use for tough flux removal cases after hand-soldering. You didn't mention what your cleaning solvent/process was. Are these residues white? If the first pass looked good, what was added afterward? Could these be evaporative residues from your cleaning solvent? > Rainer G. Blomberg > Honeywell -Space Systems Clearwater > Staff Production Engineer (727) 539-5534 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Jason Gregory Sent: Wednesday, March 09, 2005 3:56 PM To: [log in to unmask] Subject: [TN] Cleaning residues off of PCB Hello all, We have some boards that I am requiring some advice on cleaning residues. The PCBs were soldered with SN96 (Sn96.5/Ag3.5). The first pass of the boards look great. However, the second pass looked very suspicious. We are seeing residue that looks like dried, puddled flux residue around most of the leads. The areas mostly affected are multi-leaded components and there is no evidence of this residue in open (non-populated) areas of the board. If we take something like a probe or tweezers and move them along the areas of concern, then it flakes off, but not real easily. I am afraid to do this in fear of damaging the laminate (these are expensive boards). We have tried re-fluxing them with aggressive RMA flux and re-reflowing them, but to no avail. I have just tried soaking them, for 15 minutes, in a 50/50 solution of distilled white vinegar and DI water, but again, to no avail. Does anyone have any suggestions as to something else to use that's aggressive, but not damaging to polyimide (or the solder joints)? TIA, Jason Gregory Manufacturing Engineer Innova Electronics (281)653-5593 (281)653-5594 fax (281)212-0844 cell [log in to unmask] --------------------------------------------------- Technet Mail List provided as a 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/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 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/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 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/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 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/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 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/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 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------