Apparatus and method for selectively coating printed circuit panels

Claim 1

In a continuous automatic apparatus for coating circuit portions of a printed circuit panel having connector tabs, the apparatus having a device attached to a frame for gripping and transporting at variable speeds the circuit panel from station to an adjacent station, the stations including a pre-cleaning, drying, liquid coating and curing station and having an unloading guide at an exit end of the frame, the improvement comprising in the liquid coating station, having at least one wiper movable in a plane normal to the direction of movement of the circuit panel to apply a liquid coating to the panel at a pre-selected controlled volume in a plane parallel to the panel to selectively mask a portion of the panel, a first fixed edge of the wiper being in contact with the panel surface to be coated during a coating operation, a second adjustable edge forming a slot with the first fixed edge, the second edge being spaced apart from the panel surface to be coated to permit the liquid coating to flow from the wiper to the panel surface to be coated between the two edges, the first and second edges having a pair of contiguous end guards defining a first and second side of the first and second edges to prevent lateral spread of the liquid coating and a linear actuator receiving a signal adjusting the wiper to the preselected levels, the mask formed from the liquid coating, after curing, being a polymer readily removable by chemical treatment without damage to the circuit portions of the printed circuit panel.