Methods for filling holes in printed wiring boards

摘要

The invention comprises methods for filling holes in printed wiring boards and printed wiring boards produced by these methods. The methods involve plating metal conductors inside the holes of the printed wiring boards while protecting the conducting surfaces of the printed wiring boards from being plated using photoresist film. The side surfaces of a printed wiring board are covered with photoresist. The photoresist is exposed to developing light, except the photoresist covering the holes on one side of the board is masked to prevent exposure of the holes to the developing light. The undeveloped photoresist covering the holes is removed. The board is subjected to a plating process, which deposits conductive materials in the holes, but the photoresist on the conducting surfaces of the board prevents conductive materials to be plated on the surfaces of the board.