Implementing backdrilling elimination utilizing anti-electroplate coating
AssigneeInternational Business Machines Corporation
InventorsMatthew S. Doyle, Joseph Kuczynski, Phillip V. Mann, Kevin M. O'Connell
Life of this patent
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Abstract
A method and structure are provided for implementing enhanced via creation without creating a via barrel stub. The need to backdrill vias during printed circuit board (PCB) manufacturing is eliminated. After the vias have been drilled, but before plating, a plug is inserted into each via and the plug is lowered to a depth just below a desired signal trace layer. A thin anti-electroplate coating is applied onto the walls of the via below the signal trace. Then the plugs are removed and a standard board plating process for the PCB is performed.
Claims5
A structure for implementing enhanced via creation without creating a via barrel stub during printed circuit board (PCB) manufacturing comprising:
- a printed circuit board (PCB);
- said printed circuit board (PCB) having an internal conductive trace;
- a via extending through the printed circuit board (PCB) and the internal conductive trace;
- and
- an anti-electroplate coating covering the walls of the via below the signal trace;
- said anti-electroplate coating formed of a chemically resistant polymer having a selected thickness of approximately 0.2 μm, said anti-electroplate coating remaining on the via walls, preventing PCB plating from PCB plating process from taking hold on the covered via walls, said anti-electroplate coating eliminating via barrel stub creation during PCB manufacturing.
Dependencies are inferred from the claim text.