Abstract: An improved horizontal solder leveller for applying molten solder to boards while removing residual flux therefrom include a single pair of upper and lower solder sparge bars with outlet nozzles arranged so as to direct solder jets from one sparge bar toward the jets from the other sparge bar in the gap formed between the sparge bars. The gap between the sparge bars and the speed of the solder jets is sufficient to remove residual flux from a board passing therethrough as molten solder is applied to the board. An oil guide is included that directs oil to form curtains immediately upstream and downstream of the sparge bar gap to form a barrier to air flow in the gap. An oil trough upstream and downstream of the lower sparge bar limits the vertical extent of the oil curtains. Preferably a pair of castellated infeed rollers and outfeed rollers are used to move boards through the leveller.

Abstract: A horizontal solder leveller includes: solder spurge bars (21, 22) for providing downwardly and upwardly directed, distributed flow of solder, as a spray (25), through which a board (1) being tinned can pass to displace oil from contact pads on the board.

Abstract: A horizontal solder leveller for applying solder to a board comprises: means 15.sub.u,15.sub.1, 16.sub.u ; 16.sub.1 ; 17.sub.u,17.sub.1 including a solder bath 1 for applying molten solder 2 to a board. means 47 for levelling solder applied to the board, including nozzles for directing solder-levelling air jets at the board, and means 19.sub.u,19.sub.1,48 for creating a dispersion of oil in an air stream from the levelling means, the oil dispersion means being provided between the solder applying means and the levelling means.

Abstract: A board dryer comprises a double-sided conveyor for conveying flat boards through a dryer, the conveyor defining a flat board path and a conveyance direction in the path through the dryer. The dryer also comprises a pair of nozzle devices, which are elongate and arranged to extend laterally across the board path with respect to the conveyance direction, one above the board path and one below it, for directing respective laterally extensive air jets towards the board path from opposite sides thereof. The air jets have a backward component of direction with respect to a forward conveyance direction for facilitating board drying. The board dryer is especially useful for drying printed circuit boards.

Abstract: A solder leveller for tinning exposed metal on printed circuit boards comprises a solder bath and paired rollers therein for carrying a board in a curvilinear path downwardly into, through and upwardly out of the bath. At least one pair of rollers having a board engaging nip within the bath is driven. The bath includes means for providing a solder-oxidation inhibiting oil over the solder.

Abstract: A solder leveller comprises a solder bath into which a printed circuit board can be dipped to be preliminarily tinned. A pair of upright laterally acting jaws are adapted along an extended part of their length to hold the board at its opposite side edges and operate to insert in and withdraw the board from the bath. An air knife removes excess solder. The jaws are guided centrally of the bath by engagement of the side faces with the air knife nozzles which act as fixed guides.

Abstract: A solder leveller comprising a solder bath into which a board to be soldered can be inserted and then, as it is withdrawn, levelled by air knives positioned above the bath. Recirculating means are provided in the form of ducts on each side wall of the bath, the ducts having ports directing a flow of solder against opposite sides of a board to bias the board away from the sidewalls of the bath, thereby reducing the risk of the board being scratched as it is inserted and withdrawn from the bath.