摘要 |
A cover plate (28) extends over at least part of a solder reservoir (34) and has a slot (30) for a solder wave (22) to extend up above the cover plate (28). Shield gas is supplied under the cover plate (28) to blanket the solder wave (22) and prevent air from contacting the solder wave (22) and circuit boards (44) passing through the solder wave (22). Circuit boards (44) are generally supported by conveyor fingers (41, 42) at side edges and the fingers (41, 42) pass through the solder wave (22). End shrouds (50, 64) are provided at both ends of the solder wave (22) to prevent the entry of air through the conveyor fingers (41, 42) and to ensure that the side edges of the circuit board (44) are uniformly blanketed by shield gas directed to the side edges passing up through the slot (30) in the cover plate (28). The under surface, front edge back edge and side edges of a circuit board (44) are therefore uniformly blanketed by shield gas as the board passes through a solder wave (22).
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