US Patent 9511438 Solder bump forming method and apparatus

Provided is a solder bump forming method that enables micro-solder bumps to be formed without the possibility of occurrence of a bridge due to excess molten solder. An injection head 11 for supplying molten solder has a nozzle 16 brought into contact with a mask with openings that is disposed over a substrate 8. After completing a supply operation, the injection head 11 is forcedly cooled by heat transfer from a cooling unit 13 through a heater unit 12 whose operation has been stopped. Molten solder 15 in the cooled injection head 11 does not drool from the nozzle 16 when the injection head 11 moves up.