The BackDrill drill depth will be calculated as the last connection layer minus one (1) layer. If the "minimum Pin Barrel Length" value is entered, the BackDrill drill depth will be calculated as the last connection layer minus one (1) layer or the pin barrel length rounded up to the next layer, which ever is the larger length. In order to remove the pin or via barrel, a BackDrill with a diameter seven (7) thou larger than the original drill diameter is recommended. See Amphenol-TCS's ( formally Teradyne's ) White paper on Via Stubs at GB/s data transfer rates. OR Amphenol-TCS's ( formally Teradyne's ) Practical Guide to BackDrilling. |
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On the CCD_BackDrill Top and Bottom layers, a circular
doughnut marks each BackDrill location. The inner diameter represents the original drill size and the outer diameter represents the new BackDrill drill size. |
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Re-route those connections to optimize the BackDrill drill files. |