Right. It does look like a Brittle Fracture at the ENIG interface. However, at the virtical termination, I think it's just a n optical effect. A higher mag image, or an SEm one would give a better idea on that. Also, I'm not sure how good or bad the layer of electroless Ni is. regards, Vladimir SENTEC Testing laboratory Inc. Quoting "Stadem, Richard D." <[log in to unmask]>: > There is definitely a crack, and it is actually more of a separation of the > solder from the endcap perpendicular surface. It is more pronounced on the > endcap face than on the area underneath the endcap (faying surface > between the > bottom of the endcap and the top of the pad). > This indicates that the separation or crack is due to flexural > stress. It may be > due to CTE mismatch, but I doubt it. > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Ioan Tempea > Sent: Wednesday, December 15, 2010 9:09 AM > To: [log in to unmask] > Subject: [TN] Intermitent capacitor > > Dear Technos, > > > > We see intermittence in the functioning of 1206 ceramic caps after mechanical > assembly. Everything OK in Test, prior to assembly. Due to mechanical > constraints, the board is rather roughed up during integration, so I was not > surprised with the issue. But now the things get complicated: if the caps are > touched up, the intermittence goes away and everything works again. > So we've had > the capacitors x-sectionned, see images at > http://ipc-technet.groupsite.com/gallery/17220 > > > > So here come the questions: > > · If I am not wrong, I have seen comments on this very forum about > touch-up of ceramic caps actually fixing internal damage of the component, > rather than the joints, which is misleading and just a temporary fix, the cap > will stop functioning in a short while. Do I see it right? > > · Although there is an 0603 in close neighbourhood of the > problem 1206, > see image, the damage is only on the 1206. Am I wrong considering > this normal, > bigger size, higher bending, more damage? > > · The lab couldn't find anything wrong, neither in the joints, nor > internally in the part. I see a dark line at the interface between the solder > and the part in the right side image; is this normal, or an actual crack? > > · It seems the plates of the caps are perpendicular to the > PCB, instead > of parallel. This is how they came in the tape, we are not flipping > them. Would > this orientation of the plates make the component more prone to internal > cracking than parallel? > > · There indeed does not seem to be any 45 degrees cracking of the > ceramic package at the corners (indicative of mechanical stress). > Since nothing > internal has been detected either and the joints were deemed good, what else > could be the issue? > > > > Thanks, > > > > Ioan Tempea, ing. > Ingénieur Principal de Fabrication / Senior Manufacturing Engineer > T | 450.967.7100 ext.244 > E | [log in to unmask] <mailto:[log in to unmask]> > W | www.digico.cc <http://www.digico.cc/> > > > N'imprimer que si nécessaire - Print only if you must > > > > > ______________________________________________________________________ > 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 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.aspx?Pageid=E-mail-Forums 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 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.aspx?Pageid=E-mail-Forums 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 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.aspx?Pageid=E-mail-Forums for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------