Abstract: A stencil printer for printing solder paste onto a substrate includes a frame, a stencil, coupled to the frame, having apertures formed therein, a support assembly, coupled to the frame, to support the substrate in a printing position beneath the stencil, and a dispensing head coupled to the frame in such a manner that the dispensing head is configured to traverse the stencil during first and second print strokes. The dispensing head includes a frame assembly and a wiper blade assembly, coupled to the frame assembly, having first and second wiper blades that contact the stencil to print solder paste onto the stencil during a print stroke. The first and second wiper blades are constructed and arranged to force solder paste through the apertures of the stencil. The dispensing head further includes a dispensing unit, coupled to the frame assembly, having a chamber adapted to dispense solder paste, the dispensing unit being disposed between the first and second wiper blades to deposit solder paste therebetween.

Abstract: A vacuum plenum module of a stencil wiper assembly for wiping and removing excess material from a stencil of a stencil printer includes a wiper blade to wipe the stencil, a plenum chamber in fluid communication with the wiper blade, and a vacuum generator attached to and in fluid communication with the plenum chamber to create a vacuum within the plenum chamber. The vacuum plenum module further includes a fluid supply to introduce pressurized fluid into the vacuum generator, and an exhaust to exhaust fluid from the vacuum generator. The vacuum generator includes at least one vacuum ejector adapted to create the vacuum. The vacuum plenum module is further configured to move between a first position in which the vacuum plenum is spaced away from the stencil and a second position in which the vacuum plenum engages the stencil. A method of cleaning a stencil is further disclosed.

Abstract: A stencil wiper apparatus for wiping a stencil of a stencil printer includes a material supply assembly having a supply roller to deliver a roll of material, a take-up roller to receive the material, and a drive to move the material across the stencil between the supply roller and the take-up roller. The apparatus further includes a fluid delivery assembly to wet the material. The fluid delivery assembly includes an outer tube, an inner tube and a fluid delivery source. The outer tube is designed to engage the material and to deliver fluid to the material. The inner tube is positioned within the outer tube, and designed to deliver fluid to the outer tube. The fluid delivery source delivers fluid to the inner tube. A method for wiping a stencil of a printing machine is further disclosed.