Although I have read the Small Hole Reliability study by the
          IPC, I feel that it is very outdated (1988?).  In those
          days, board fabricators were on a learning curve for small
          holes.  Many process improvements have been put in place
          since then, including vibrators in the deposition baths to
          remove entrapped air bubbles.
          I stand by my earlier staement that removal of
          non-functional pads is much preferred by board houses.  As
          layers increase, the amount of copper drilled through can be
          as much as .016" - .018"!
          It is time for the IPC to do another study instead of
          relying on a seemingly outdated document.
          Tom Coyle
          Field Services Engineer
          HADCO Corporation
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