Some paste manufacturers can supply fluorescent versions of their products, these light up under Ultra violet light, thus helping to identify and control the problem. Regards Mike Fenner Applications Engineer, European Operations Indium Corporation T: + 44 1908 580 400 M: + 44 7810 526 317 F: + 44 1908 580 411 E: [log in to unmask] W: www.indium.com Leadfree: www.Pb-Free.com -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Grant Emandien Sent: Tuesday, April 22, 2003 10:51 AM To: [log in to unmask] Subject: Re: [TN] problem with gold pads of the pcb If grey, then in all likelihood it is spatters of reflowed paste - the grey dots are present before your aqueous wash. Your paste app processes should be checked or what about the oven temp profile - has this been qualified? If black, then bigger problems persist i.e. possibly oxidised nickel, but easily checked on bare board. -----Original Message----- From: Prashant Chopra [mailto:[log in to unmask]] Sent: Tuesday, April 22, 2003 8:59 AM To: [log in to unmask] Subject: [TN] problem with gold pads of the pcb hi all, we are using gold finger pads on the pcb. but after going thru smt process of screen printing,component insertion, reflow and aqueous wash we are facing the problem of grey color dots on the pads. This problem is with the pads where no components are being placed. There is no solder paste printing on these pads nor any components are place there and they are being covered with Kapton tape thru out the above process. Can anyone point to some reasons for this problem????? --------------------------------------------------- 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 ----------------------------------------------------- ********************************************************************** Notice: This email transmission contains confidential information which is the property of the sender and if you are not the intended recipient, you are hereby notified that any disclosure, copying or distribution of the contents of this e-mail transmission, or the taking of any action in reliance thereon or pursuant thereto, is strictly prohibited. Should you have received this e-mail in error, please notify us immediately to arrange for the return of the documentation comprising this transmission. No warranty is given by Tellumat (Pty) Ltd regarding the integrity of this e-mail, nor that this e-mail is free of viruses, interception or interference. Unless otherwise stated, any views or opinions contained in this e-mail are that of the sender. Tellumat (Pty) Ltd furthermore disclaims liability for any unauthorised opinion or representation made by the sender purportedly on behalf of Tellumat (Pty) Ltd. Accordingly, Tellumat (Pty) Ltd's delegation of authorities, setting out who may contract on behalf of Tellumat (Pty) Ltd, is available on request to the recipient. ********************************************************************** --------------------------------------------------- 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 -----------------------------------------------------