I have a few assemblies that a customer had asked me to look at and I noticed an oddity around the vias.  It looks like there is delamination around the vias.  Steve was kind enough to post these photo's on his web page for all to view.  I need to know if this is delamination or just haloing. I saw an issue like this a long time ago (15 years ago) and at that time we scrapped them because we didn't know what the issue was caused by.  Some at that time thought the drill bit for that size was either pushed to fast through the material causing a slight delanmination or the drill bit was dull.  

I appreciate any assistance or thoughts on the issue.  I have already suggested that a cross section may have to be completed.

http://www.stevezeva.homestead.com 

Thanks in advance.

Kathy