There are a few possibilities here - whether the pads were degraded by the multiple cycling or not and / or any good to start with, and secondly if a bare board shows the same issues; whether there is contamination only on the pads such as would be the case in a bad resist develop / strip process. Either way putting a bare board through will throw some light on the issue John Burke (408) 515 4992 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Tan Geok Ang Sent: Thursday, October 09, 2008 6:23 PM To: [log in to unmask] Subject: Re: [TN] PCB pad non-wetting issues The question is why it only happened on the solder side pads (believed that solder flow through PTH barrel and fillets formed on the component/top side of the board). Either black pad issue on the solder side or the wetting/contact time is too long at wave soldering process. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Paymon Sani Sent: Thursday, 9 October 2008 10:54 PM To: [log in to unmask] Subject: Re: [TN] PCB pad non-wetting issues No, this is a good suggestion. I will propose it based on the PCB pricing and failure rate. Thank you, Paymon -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of John Burke Sent: October 9, 2008 10:25 AM To: [log in to unmask] Subject: Re: [TN] PCB pad non-wetting issues Have you tried running a bare board through to confirm/eliminate the heating cycles? John Burke (408) 515 4992 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Paymon Sani Sent: Thursday, October 09, 2008 6:57 AM To: [log in to unmask] Subject: [TN] PCB pad non-wetting issues Hello All, We are experiencing a pad non-wetting issue for the though-hole component pads ONLY! The PCB goes through few heat cycles with top and bottom side assembly during at SMT process and then through-hole assembly at wave process. The problem is found at Wave process. The Pb solder does not wet to the through-hole component pads on the solder side only! An SEM/EDS evaluation revealed high concentration of P in the Nickel and Nickel/Tin intermetalic layer of 11% to 21%. I would like to ask anyone if they have experienced a similar defect in the past. What is the Root Cause? Thank you in advance, Paymon --------------------------------------------------- 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 ----------------------------------------------------- __________ NOD32 3475 (20080926) Information __________ This message was checked by NOD32 antivirus system. http://www.eset.com --------------------------------------------------- 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 ----------------------------------------------------- __________ NOD32 3475 (20080926) Information __________ This message was checked by NOD32 antivirus system. http://www.eset.com --------------------------------------------------- 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 -----------------------------------------------------