George I feel if the nickel in some areas is much lower than surrounding ones it would show that nickel erosion was higher and so the oxidation after 1st pass would show up as poor joint in wave or 2nd pass. But as u say 3 is par for course and should not allow cu oxidation. We are in a gray area. The pads we identified measured much lower - in the region of 1 to 1.2 Nickel. Gold was I think hgher. Worthwhile studying boards with black pad issues on the XRF Anil -----Original Message----- From: Wenger, George M. [mailto:[log in to unmask]] Sent: Friday, June 10, 2011 3:45 PM To: TechNet E-Mail Forum; Anil kher Subject: RE: [TN] Black Pad? What happens if the nickel is 1.5 to 3 microns? Regards, George George M. Wenger Senior Principal Reliability / FMA Engineer Andrew Corporation - Wireless Network Solutions 40 Technology Drive, Warren, NJ 07059 (908) 546-4531 Office (732) 309-8964 Mobile E-mail: [log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Anil kher Sent: Friday, June 10, 2011 3:38 AM To: [log in to unmask] Subject: Re: [TN] Black Pad? We found an easy method to determine Black Pad. Check under an XRF with Gold/ nickel calibration. If no black pad the nickel will be ~ 3 to 5 microns. Wherever the nickel goes down to 1/1.5 microns and gold shows same - sure u hv black pad. Of course - that is how black pad is formed. But well in the hole - a cross section will be better. Its also the layout which causes black pad - we observed some pads with very low nickel and the same would not solder. Nearby bigger pads showed adequate Ni and soldered well. My 2 bits Anil Kher -----Original Message----- From: Gerry Gagnon [mailto:[log in to unmask]] Sent: Thursday, June 09, 2011 11:19 PM Subject: Re: Black Pad? Me too. It looks like oxidized nickel which will not wet. > Date: Thu, 9 Jun 2011 09:12:00 -0700 > From: [log in to unmask] > Subject: Re: [TN] Black Pad? > To: [log in to unmask] > > I'm with Steve on this one... > > Paul > > Paul Edwards > Process/Quality Engineering > Surface Art Engineering > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory > Sent: Thursday, June 09, 2011 6:59 AM > To: [log in to unmask] > Subject: Re: [TN] Black Pad? > > Hi Gary, > > I got your pictures this morning, and have them posted now: > > http://stevezeva.homestead.com/Joint_1.JPG > > http://stevezeva.homestead.com/Joint_2.JPG > > http://stevezeva.homestead.com/via.JPG > > Although the pictures show some non-wetting happening, it's difficult to see > what exactly is going on. > > You say that the component side seems fine, it's just when you're trying to > wave solder is when you see the problem. Maybe you have thin gold, and when > the boards were fresh, the SMT was able to solder fine. But then after the > boards went through reflow, the underlying nickel oxidized so badly that > solder wasn't able to wet? > > Steve > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Gary Robinson > Sent: Wednesday, June 08, 2011 4:46 PM > To: [log in to unmask] > Subject: [TN] Black Pad? > > We have noticed a problem only on ENIG boards in our WAVE process that looks > similar to Black Pad but do not know how to identify or where to begin to > find a resolution to the problem. We were hoping an expert may have > experience in seeing this problem. Here are some facts - > 1. Black residue is on the vias and thts on the solder side. Please see the > attached images. > 2. Component Side SMT Parts do not exhibit the same problems. > 3. Boards are processed PbFree - SAC305, Pacific 2009m No Clean Water Based > flux > 4. THTs will not wet after residues appear (for touch up process) > 5. Blowholes appear to accompany the defect but are not always present. > > Thanks for your help in advance. > > > ______________________________________________________________________ > This email has been scanned by the MessageLabs Email Security System. > For more information please contact helpdesk at x2960 or [log in to unmask] > ______________________________________________________________________ > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using LISTSERV 16.0 > 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 > For additional information, or contact Keach Sasamori at [log in to unmask] or > 847-615-7100 ext.2815 > ----------------------------------------------------- > > > ______________________________________________________________________ > This email has been scanned by the MessageLabs Email Security System. > For more information please contact helpdesk at x2960 or [log in to unmask] > ______________________________________________________________________ > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using LISTSERV 16.0 > 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 > For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 > ----------------------------------------------------- > > > =========================================================================== == > > This email and any attachments thereto may contain private, confidential, and > privileged material for the sole use of the intended recipient. Any review, copying, > or distribution of this email (or any attachments thereto) by others is strictly prohibited. > If you are not the intended recipient, please contact [log in to unmask] > immediately and permanently delete the original and any copies of this email and > any attachments thereto. > > =========================================================================== == > > > ______________________________________________________________________ > This email has been scanned by the MessageLabs Email Security System. > For more information please contact helpdesk at x2960 or [log in to unmask] > ______________________________________________________________________ > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using LISTSERV 16.0 > 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 > For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 > ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------