| 摘要 |
PROBLEM TO BE SOLVED: To make a nitrogen atmosphere heating furnace and a cleaning appara tus unnecessary in a soldering process of an electronic circuit device, and realize a high precise ball terminal of BGA or the like and correction technique. SOLUTION: On lands 1c of an 1C package 1, solder is stuck and is upper part is covered with liquid 8 whose boiling point is higher than a melting point of the solder. The stuck solder 7 is heated, method and solidified at a temperature lower than or equal to the boiling of the liquid 8, and ball terminals are formed. After that, the liquid 8 is boiled and vaporized in a decompression chamber. In other case, by locally heating the stuck solder 7 parts, solder is heated and cooled not being in contact with oxygen in atmospheric air under a condition that the liquid 8 is not boiled and evaporated. As result, nitrogen atmosphere heating and cleaning are made unnecessary. |
