PURPOSE: To continuously form solder layers while successively allowing many sheets of circuit boards to travel by heating the circuit boards coated with a solder depositing compsn. to bring the solder depositing compsn. into reaction and selectively depositing Sn-Pb alloy solder on the pads of the circuit boards.
CONSTITUTION: The circuit boards are automatically determined in the positions relative to the line by an arraying conveyor 22 and enter a printing device 23. The pasty solder depositing compsn. contg. org. Pb and Sn powder is applied on the pad regions of the circuit boards by a screen printing method in this device. The circuit boards coated with the solder depositing compsn., then, enter a heating furnace 24 where the circuit boards are heated and the solder depositing compsn. induces a chemical reaction to deposit the Sn-Pb alloy solder selectively on the pads of the circuit boards. Further, the circuit boards emitted from the heating furnace 24 enter a washing device 26 by passing a transition 25 where the residues produced by the reaction of the solder depositing compsn. are washed way.
FUKUNAGA TAKAO
KONO MASANAO
IRIE HISAO
HARIMA CHEMICALS INC
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