Htc Corporation

Walter J Hall

Donald J Spigarelli

Douglas J Peck

James L Finney

A vapor phase system for soldering of a workpiece. A vessel for containing an electronic liquid which is heated to generate a zone of saturated vapor. A first inclined throat communicates with the vessel and a solder pot is located within the vessel. The solder pot including a reservoir for containing molten solder, a second throat aligned with the first throat and communicating at one end with molten solder contained in the reservoir means and communicating at the other end with the saturated vapor, molten solder contained in the reservoir means is pumped through the second throat and is captured by the reservoir and a conveyor carries work product through the first throat, through the saturated vapor and into the second throat whereby the work product will become immersed in the molten solder contained within the second throat.

Apparatus for solder removal

A solder leveling system for use in vapor phase soldering of printed wiring boards. A transport system operating in a near-horizontal mode moves the board to be solder coated through a vapor zone in a chamber having a solder pot which has a throat in line with the plane of the transport system. The near-horizontal movement through the vapor and into and out of the solder pot prevents solder sag and permits control of the thickness of solder deposited on the opposing board surfaces. Leveling nozzles are positioned in a vapor-filled chamber astride the transport system between the solder pot and the chamber throat. Perpendicular nozzle offset distance from the board and nozzle angle are adjustable. Preferably one nozzle projects a stream normal to the board, with the other nozzle projecting a grazing stream for clearing through holes. A nozzle flow rate corresponding to a predetermined energy threshold provides reliable hole clearing. Preferably the chamber throat is cooled for vapor containment, forming one of three cooling zones for vapor containment, vapor leveling, and condensation. In the preferred solder pot, as the board enters the sloping throat, solders spills over a weir into a reservoir from whence it is pumped into a standpipe which charges the sloping throat. Preferably solder is added to the pot through a drop tube having a lower end immersed in the solder to provide a unique vapor seal and means for determining the level of solder. A preferred transport system utilizes a spring loaded carrier providing easy loading and unloading of the boards.

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New Corner, MA, United States of America

Walter J Hall