A soldering system comprising a solder pot and a nozzle exchange unit. The solder pot is configured to detachably couple to a solder nozzle during a soldering operation. The nozzle exchange unit is arranged to: store a plurality of solder nozzles; detach a first nozzle from the nozzle coupling; and attach a stored second nozzle to the nozzle coupling.

A soldering device includes a detection sensor which can detect a liquid level height of molten solder inside a solder bath. It is determined whether or not a detection height which is the detected liquid level height is greater than or equal to a first set height which is arbitrarily set. In a case where the detection height is greater than or equal to the first set height, it is estimated that the amount of molten solder capable of performing a soldering work for a predetermined number or more of boards is stored in the solder bath. The amount of molten solder stored in the solder bath is estimated by multiplying a difference between a detection height which is the detected liquid level height of the molten solder and a second set height which is preset, by an area inside the solder bath in a horizontal direction.

Provided is a jet nozzle that varies a width of a flow of jetted molten solder. The jet nozzle contains a nozzle main body having a channel section at its part and a molten solder flow width varying member that varies a width of the upper opening end of the nozzle main body by a slide of the molten solder flow width varying member within the channel section of the nozzle main body to vary a width of the molten solder flow jetted from the upper opening end of the nozzle main body. The molten solder flow width varying member includes a molten solder flow width varying plate that varies the width of the molten solder flow, a rectangular rectifying piece that extends along a slide direction of the molten solder flow width varying member, and a sliding shaft that slides the rectifying piece.

A wafer via solder filling device includes a solder bath comprising an accommodation space for accommodating a molten solder, with an open top, and an air outlet for exhausting air from the accommodation space; a fixing unit for fixing the wafer having a via formed in one surface in the accommodation space to seal the accommodation space airtight; and a pressing unit for pressing a bottom of the molten solder arranged in the solder bath and moving the molten solder upward, to fill the molten solder in the via.

Provided is a jet nozzle that varies a width of a flow of jetted molten solder. The jet nozzle contains a nozzle main body having a channel section at its part and a molten solder flow width varying member that varies a width of the upper opening end of the nozzle main body by a slide of the molten solder flow width varying member within the channel section of the nozzle main body to vary a width of the molten solder flow jetted from the upper opening end of the nozzle main body. The molten solder flow width varying member includes a molten solder flow width varying plate that varies the width of the molten solder flow, a rectangular rectifying piece that extends along a slide direction of the molten solder flow width varying member, and a sliding shaft that slides the rectifying piece.