| 摘要 |
<p>A method and apparatus for leveling and controlling the thickness of conductive material on the walls of the through holes of a printed circuit board and for removing excess conductive material therefrom the steps comprising, immersing a printed circuit board having conductive material deposited in the through holes thereof into a heated bath of a heated conductive material, heating the conductive material in the through holes until said conductive material is in a molten state and, while said conductive material is molten, gyating said circuit board in said bath in a plane substantially normal to the axis of said through holes and thereby causing said molten conductive material to flow circumferentially and axially of said through holes to form a level and uniform coating of said conductive material on the walls of said through holes and cause any excess of said conductive material to flow out of said through holes onto the surfaces of said circuit board; said apparatus including a heated bath of heat conductive material, means for supporting at least one circuit board in said bath and means for gyrating a circuit board supported in said bath in a plane substantially normal to the axis of through holes passing through said board.</p> |
