I still think they look a lot like vias but some would have to be micro vias. Yes, the consistent "Roundness" sure looks like via clearance etch back. But it is SO SIMPLE - Are there holes? :-) Bob K. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of David Hillman Sent: Tuesday, July 29, 2014 3:21 PM To: [log in to unmask] Subject: Re: [TN] Trying to figure out possible mechanism for contamination Hi gang - I had the same first impression as Dick that these were solder splatters from reflow/wave/stencil but when I looked closer, it the splatters are very very uniform in size plus the center "dot' is equally uniform. Someone had mention a filled micro via delamin-ish problem could be the root cause. Take a look at the photo again - doesn't it seem that these are too uniform for a solder splatter root cause? Dave Hillman Rockwell Collins [log in to unmask] On Tue, Jul 29, 2014 at 11:30 AM, Richard Krug <[log in to unmask]> wrote: > To me it looks like solder paste spatter / fines that landed on ENIG > surface. Can be caused by too steep a ramp rate during preheat stage > of reflow profile. Was measured reflow profile within manufacturer's spec? > > Dick Krug, CSSBB, CSMTPE > Lead Process Engineer > Sparton Brooksville, LLC > 30167 Power Line Road > Brooksville, FL 34602-8299 > p (352) 540-4012 (Internal Ext. 2012) [log in to unmask] > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of John Foster > Sent: Tuesday, July 29, 2014 12:13 PM > To: [log in to unmask] > Subject: [TN] Trying to figure out possible mechanism for > contamination > > We have been seeing a problem recently on several different CCA'S that > we are having assembled. > The boards are ENIG with plug and plate. The assembly shop is > assuring us that these gold areas are being Protected during the > entire assembly process with kapton tape. > I was thinking it was flux splatter since the areas are always almost > perfectly circular. > The locations are very random and range from nothing to what is in the > picture. > Is there any other mechanism that might be causing this? On our next > run I am going to go to the shop To witness the taping. But I was > curious if maybe it's some other cause. > Mr. Gregory was kind enough to post a picture. > http://stevezeva.homestead.com/spots.jpg > > Any thoughts would be appreciated > Thank You > John Foster > L3 Communicatons > > Confidentiality Notice: The information contained in this message is > intended only for the use of the addressee, and may be confidential > and/or privileged. If the reader of this message is not the intended > recipient, or the employee or agent responsible to deliver it to the > intended recipient, you are hereby notified that any dissemination, > distribution of copying of this communication is strictly prohibited. > if you have received this communication in error, please notify the sender immediately. > > Warning: This document may contain technical data within the > definition of the International Traffic in Arms Regulation (ITAR) and > is subject to the export control laws of the U.S. Government. > Transfer of this data by any means to a foreign person, whether in the > United States or abroad, without an export license or other approval > from the U.S. Department of State, is strictly prohibited > > > ______________________________________________________________________ > This email has been scanned by the Symantec Email Security.cloud service. > For more information please contact helpdesk at x2960 or > [log in to unmask] > ______________________________________________________________________ > > ______________________________________________________________________ > This email has been scanned by the Symantec Email Security.cloud service. > For more information please contact helpdesk at x2960 or > [log in to unmask] > ______________________________________________________________________ > ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________