Abstract: A quick-change material module of a stencil wiper assembly for wiping a stencil of a stencil printer includes a supply roller to receive a roll of material, a take-up roller to receive used material, and a drive to move the material across the stencil between the supply roller and the take-up roller. The supply roller is designed to move between an operating position in which the module functions to wipe the stencil and a changing position in which the supply roller is accessible to change the roll of material. A pivot mechanism is further disclosed for pivoting the supply roller between the operating and changing positions. A frame supports the supply roller, the take-up roller, and the drive. The pivot mechanism includes at least one pivot arm having one end rotatably attached to the supply roller and an opposite end pivotably attached to the frame.

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.

Abstract: A printer includes a print head for dispensing viscous material, such as solder paste. The print head defines a chamber and includes at least one source port and a dispensing slot. Within the chamber, a flexible membrane segregates the chamber into a dispensing region and an activation region. Viscous material flows from a supply mounted to the source port, into the dispensing region and out the slot. A displacement mechanism is positioned to displace the flexible membrane to reduce the volume of dispensing region and to thereby dispense viscous material through the slot. The print head also includes a removable envelope through which the viscous material flows and contacts as it passes through the envelope.

Abstract: A system for depositing solder paste on a print window of a printed circuit board through a stencil includes a housing providing a printing chamber, a depositor configured to move relative to the housing and to deposit the solder paste, a support device disposed in the printing chamber and configured to receive the circuit board and to selectively hold the circuit board stationary relative to the housing, a loading mechanism configured to receive the circuit board and to transport the circuit board along a second direction to the support device, a controller coupled and configured to control dispensing of the solder paste by the depositor and the transporting of the circuit board by the loading mechanism, and a rotational apparatus coupled to the support device and configured to rotate the support device, where the controller is configured to cause the rotational apparatus to rotate the support device more than about 10° and to cause the depositor to deposit solder paste onto the circuit board after the r

Abstract: An apparatus and method for cleaning excess solder paste that is deposited on a stencil in a stencil printer. The apparatus includes a solvent bath containing a pool of solvent in which a bar is disposed in the solvent bath. The bar rotates in the solvent bath and surface tension between the bar and the solvent causes the solvent to uniformly adhere to the bar. The bar is used to apply solvent to a cleaning material that is used to wipe excess solder paste from the stencil.

Abstract: An apparatus and method for cleaning excess solder paste that is deposited on a stencil in a stencil printer. The apparatus includes a solvent bath containing a pool of solvent in which a bar is disposed in the solvent bath. The bar rotates in the solvent bath and surface tension between the bar and the solvent causes the solvent to uniformly adhere to the bar. The bar is used to apply solvent to a cleaning material that is used to wipe excess solder paste from the stencil.