Patent ID: 7708183

Claim:
A reflow solder oven, comprising: a conveyor mechanism for moving printed circuit boards through at least one heating zone followed by at least one cooling zone, the cooling zone including: a gas flow path with a gas intake, a heat exchanger, a plenum and a diffuser, the heat exchanger positioned downstream of the gas intake for cooling gas flowing thereby, the plenum downstream of the heat exchanger for receiving cooled gas from the heat exchanger, the diffuser having an upper surface exposed to the plenum and a plurality of nozzle openings arranged to direct cooled gas from the plenum downward toward printed circuit boards on the conveyor mechanism, each of the plurality of nozzle openings formed by a surrounding wall portion extending upwardly from the upper surface to an upper portion, the upper portion extending radially inwardly to a downwardly extending wall portion, the downwardly extending wall portion ends at the nozzle opening such that the nozzle opening is located below the upper portion, the surrounding wall portion acts to restrict condensed flux on the upper surface of the diffuser from flowing through the nozzle openings toward printed circuit boards, where the surrounding wall portion is separated from the downwardly extending wall portion by an annular air gap, the diffuser being of metal plate construction and the surrounding wall portion, upper portion and downwardly extending wall portion being unitary with the metal plate.