Take a look at the board stack-up. If you have dielectric spacings between layers of 8 mils or somewhere near 8 mils, it might have been built using a single ply of 7628 prepreg (to keep cost down), this is not a good practice. Separation between innerlayers or broken vias can be a risk. thanks, -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Dwight Mattix Sent: Wednesday, September 19, 2012 11:55 AM To: [log in to unmask] Subject: Re: [TN] Broken Vias That is a (most) robust combination. The San Ei is the benchmark for via fill reliability in our applications and experience. We have several applications that it is the _only_ via fill to pass our reliability demonstration. Use it in combination with several materials: most commonly FR370HR or an equivalent. At 05:37 PM 9/18/2012, Robert Kondner wrote: >Hi, > > > >This is a follow up on the broken vias on a board with plugged and plated >through vias. > > > >The laminate is 370HR (Tg 180) and the fill material is PHP-900 IR-6P from >San-Ei Kagaku (Tg 168). > > > >I do not have cross section pictures yet. > > > >If anyone has any ideas on how these material might react to a lead free >reflow process and via barrels would be broken please let me know. I am >interested in any and all ideas. > > > >Bob K. > > > >______________________________________________________________________ >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] ______________________________________________________________________