Abstract: The present invention relates to a device for generating a wave of solder in a wave soldering machine used for soldering components on printed circuit boards passing through the machine, said device being equipped with a nozzle comprising an elongated chamber with convergent walls and a discharge opening at its upper part, which opening extends below the displacement path of the printed circuit boards and through the entire width of said path, said nozzle, which is connected with a reservoir supplying liquid solder and equipped with heating elements, being designed to send an upwardly directed stream of solder which forms a wave, the said wave licking the lower face of the printed circuit boards and the components leads protruding therefrom. Said device is equipped, close to the opening of the nozzle, with at least one auxiliary heater capable of heating up the solder in the vicinity of the wave and to keep its temperature there to a value higher than a given value.