Method of processing substrate using jet soldering apparatus

A method of processing a substrate using a jet soldering apparatus having:

• a first housing;
• a first supply port provided on the first housing and configured to provide first molten solder, the first supply port having a plurality of openings arranged in a plurality of rows along a substrate conveyance direction;
• a second housing;
• a second supply port provided on the second housing and configured to provide second molten solder, the second supply port being a slit-shaped opening;
• a conveyance unit configured to convey the substrate, the conveyance unit including a conveyance rail;
• and a drive unit, wherein a distance between the first supply port and the second supply port along the substrate conveyance direction is smaller than a width, along the substrate conveyance direction, between:
• (i) the furthest upstream point of the furthest upstream opening of the plurality of openings of the first supply port;
• and (ii) the furthest downstream point of the furthest downstream opening of the plurality of openings of the first supply port;
• and the distance between the first supply port and the second supply port along the substrate conveyance direction is smaller than a width of the second supply port along the substrate conveyance direction,
• the method comprising:
• a step of providing the first molten solder from the first supply port;
• and
• a step of providing the second molten solder from the second supply port,
• wherein the first molten solder and the second molten solder are mixed so as to obtain mixed molten solder,
• wherein the mixed molten solder does not fall back into a solder supply between the first supply port and the second supply port along the substrate conveyance direction,
• wherein an upper surface of the mixed molten solder is not positioned below a lower end of the conveyance rail in an entire length region along the substrate conveyance direction between the first supply port and the second supply port such that the mixed molten solder is not separated from the substrate conveyed along the conveyance rail by the conveyance unit in an entire area between the first supply port and the second supply port, and
• wherein an amount of the first molten solder is 0.8 times or more and 1.2 times or less of an amount of the second molten solder.