| 摘要 |
PROBLEM TO BE SOLVED: To provide a method capable of controlling the concentration of tin ions higly precisely in an electrotinning method using an insoluble electrode. SOLUTION: The flow rate of a plating liquid to be fed to a plating liquid circulation tank 4 is controlled by using a feedforward control flow rate calculated based on the schedule consumption rate of tin ions after a fixed time obtained from a production schedule, and a feedback control flow rate calculated based on the difference between the record value of the concentration of the tin ions in the plating liquid fed from the plating liquid circulation tank 4 to an electroplating tank 5 and the target value thereof at the point of the time in the calculation of the feedforward control flow rate. COPYRIGHT: (C)2006,JPO&NCIPI
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