Hey Mike, The residues are only on the second pass side. The first pass side looks great. Go USC! Jason Gregory Manufacturing Engineer Innova Electronics (281)653-5593 (281)653-5594 fax (281)212-0844 cell [log in to unmask] -----Original Message----- From: [log in to unmask] [mailto:[log in to unmask]] Sent: Thursday, March 10, 2005 8:51 AM To: TechNet E-Mail Forum; Jason Gregory Subject: Re: [TN] Cleaning residues off of PCB Are the residues on both sides of the board or just the first reflowed side? I've seen some resides under low standoff components migrating back out after another thermal cycle. If you pull a part do you see residues underneath the part - might tweak the stencil (homeplate) and/or reduce the solder paste volume to limit flux entrapment. Mike Sewell Jason Gregory <jgregory@INNOVAE To: [log in to unmask] LEC.COM> cc: Sent by: TechNet Subject: Re: [TN] Cleaning residues off of PCB <[log in to unmask]> 03/10/2005 08:14 AM Please respond to TechNet E-Mail Forum; Please respond to Jason Gregory Ramon, the boards were mine, not Steve's. Anyway, the process WAS first pass print, place, vapor phase reflow, clean with vapor degreaser and terpene. Then second pass print, place, VP reflow, then clean again with vapor degreaser and terpene. All of the first passes were through VP reflow. After we ran our first topside and saw the residue, we switched to convection and got the same results. We initially thought our VP fluid became contaminated. The residue only comes off with something hard, like a probe or tweezers. 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 Dehoyos, Ramon Sent: Thursday, March 10, 2005 7:58 AM To: [log in to unmask] Subject: Re: [TN] Cleaning residues off of PCB Hi Steve: Will you describe step by step the process that these boards go through. Are these type of boards the only affected? Or did the process all of a sudden produced this results? Does the contamination come off by scrubbing it with an alcohol soaked Q tip? Regards, Ramon -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Jason Gregory Sent: Wednesday, March 09, 2005 6:37 PM To: [log in to unmask] Subject: Re: [TN] Cleaning residues off of PCB Photo posted. Thanks Steve! You can see (barely - sorry bad photo) some halo-ing around the leads. Like I said, no other detection in open areas or two leaded devices just finer pitch, multi-leaded devices. Follow the link http://www.stevezeva.homestead.com/files/residue_closeup.jpg 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 David D. Hillman Sent: Wednesday, March 09, 2005 4:05 PM To: [log in to unmask] Subject: Re: [TN] Cleaning residues off of PCB Hi Jason! Can you send a photo to Steve for posting? A visual would help. Dave Hillman Rockwell Collins [log in to unmask] Jason Gregory <jgregory@innovae lec.com> To Sent by: TechNet [log in to unmask] <[log in to unmask]> cc Subject 03/09/2005 02:55 [TN] Cleaning residues off of PCB PM Please respond to TechNet E-Mail Forum <[log in to unmask]> ; Please respond to Jason Gregory <jgregory@innovae lec.com> 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 ----------------------------------------------------- __________________________________________________________________ This message may contain information that is privileged and confidential to LaBarge, Inc. 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