Ralph, You said: > I also mention that a good design, where long-term reliability is a > serious design requirement, does not have closely spaced (~1mm > edge-to-edge) of plated-through holes on the same grid lines to where > the reinforcement yarns bridge the spacing between holes. It is better > to off-set the plated-through holes either diagonally or such that > plated-through hole centers are on a grid that is greater than half of > the sum of their hole diameters. Does this mean that a 0.016" finished via, drilled at lets say 0.021", would have a center to center spacing of 0.060 minimum (0.039 + 0.021 = 0.060) ? --------------------------- John Laur Rockwell Automation Allen-Bradley Co Inc. 1201 South Second Street Milwaukee, WI 53204 +1 414 382 2162 (fax) +1 414 382 2393 (phone) [log in to unmask] --------------------------- *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************