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