Abstract: An apparatus and method for treating the walls of apertures passing through a planar substrate with a fluid treatment solution. The method comprises placement of a pressurized fluid wedge beneath, above, or both beneath and above a planar substrate as it passes through a treatment chamber. The apparatus that forms the fluid wedge is a roller assembly comprising a roller within a shroud which carries fluid as it rotates through a gap between the roller and the shroud. The roller provides the dual function of forming the fluid wedge and conveying the planar substrate through the treatment chamber.

Abstract: An apparatus and method for treating the walls of apertures passing through a planar substrate with a fluid treatment solution. The method comprises placement of a pressurized fluid wedge beneath, above, or both beneath and above a planar substrate as it passes through a treatment chamber. The apparatus that forms the fluid wedge is a roller assembly comprising a roller within a shroud which carries fluid as it rotates through a gap between the roller and the shroud. The roller provides the dual function of forming the fluid wedge and conveying the planar substrate through the treatment chamber.