| 摘要 |
<p>A method of making a plate through hole printed circuit board, comprises the steps of: a) forming conductive circuit elements (10) on two opposed faces of a paper phenolic containing substrate (11); b) coating the substrate and circuit elements with a de-sensitising material (12); c) forming holes (13) through the substrate, each hole passing through a circuit element on each of the opposed faces of the board; d) treating the board to render the substrate exposed in the holes receptive to the action of a metallic plating solution; e) removing the de-sensitising material; f) printing an acid-resist mask (14) on to both faces of the board, the mask leaving exposed only a small area of the board surrounding each hole therethrough; and g) treating the board with an electroless nickel-plating solution to deposit nickel (15) in the holes to the desired thickness to provide an electrical connection through each hole between two opposed conductive circuit elements.</p> |
