Abstract 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.
The process as described in claim 1 wherein said heating is accomplished by dipping said circuit board into a hot wax bath.
Claim 2
Dependent Claim
18 words
A process as recited in claim 1 in which said board is gyrated through a substantially circular orbit.
Claim 3
Dependent Claim
18 words
A process as recited in claim 1 in which said board is gyrated through a substantially elipitcal orbit.
Claim 4
Dependent Claim
198 words
A process for uniformly coating through holes of a printed circuit board with conductive material and for removing the excess of said conductive material from said through holes, comprising the steps of: a. horizontally mounting a printed circuit board having a conductive material in the through holes upon a flexibly suspended frame; b. dipping said frame and circuit board into a heated bath and heating said conductive material to at least its plastic state; c. while said frame and circuit board are in said heated bath and said conductive material is heated to its plastic state, applying at selected locations about said frame a series of repetitive horizontal forces in an application sequence that imparts to said printed circuit board an orbital motion about a vertical axis and a gyrating motion to said plastic conductive material in said through holes; d. continuing said orbital and gyrating motion in said heated bath until said plastic material is distributed uniformly, circumferentially and axially of said through holes and the excess of said conductive material is removed therefrom; and e. while continuing said orbital and gyrating motion, removing said frame and circuit board from said bath and solidifying said conductive material.
Claim 5
Dependent Claim
29 words
A process as recited in claim 5 in which said repetitive horizontal forces applied to said printed circuit board are substantially equal and said orbital motion is substantially circular.
Claim 6
Dependent Claim
29 words
A process as recited in claim 5 in which said repetitive horizontal forces applied to said printed circuit board are unequal forces and said orbital motion is substantially eliptical.