| 摘要 |
PURPOSE:To form with coating the presoldering layer in an uniform thickness on the wafer surface and to improve the working efficiency by holding a semiconductor wafer by a rotary type wafer holder and rotating it at high speed just after lifting the wafer from a molten solder. CONSTITUTION:The semiconductor wafer 1 holding a wafer holder 2 on a chuck mechanism 3 with its hanging down is dipped into the molten solder 51 inside a solder tank 5. In this case, it is dipped into the solder 51 with inclining the position of the wafer holder 2 by an angle beta from the level so that no air may be included. The driving motor of the holder 2 is started in succession just after lifting the wafer 1 from the molten solder with the lifting operation by inclining by the angle beta. With this rotary driving, the wafer 1 is rotated at high speed centering around the rotary shaft of the chuck mechanism 3. The excess solder and oxide, etc., sticked on the surface of the wafer 1 are scattered around and the pre-soldered layer in uniform thickness is formed on the wafer surface with coating thereon. |
