At 04:25 PM 2/9/96 MST, you wrote: > > I have a 14-layer SMT digital, polyimide, impedance controlled board per >IPC-D-275,Class3. >The coupon requires a section D. What really is the difference between >Option 1 and Option 2 >and how does the conductor routing for all of the layers work out in this >section. > > o--------------o o o o o o o o > / > / > o--- o o o o o o o > > > o--- o o o o o o o > \ > \ > o-------------o o o o o o o o > >The above is my best attempt at drawing a Section D, that I think I need. > My question is >about the routing between these vias....."so that the interconnects in a >specific hole are >separated to the greatest extent possible." (IPC-D-275 page 82 7.3.7.2 >Option 2 third para- >graph) > > Thanks ahead of time, > DaveS > Dave, The explanation could be rather lengthly for this forum. However, I would be happy to discuss the differences and other criteria, surrounding the "D" coupon. I can be reached at: Gary Ferrari Tech Circuits, Inc (203)269-3311 Regards, Gary Ferrari Chairman - IPC-D-275