| 摘要 |
An electroplating apparatus comprises a plating tank, first, intermediate, and final rinse tanks, and a plurality of weirs which connect the plating tank and the first rinse tank, the first and intermediate rinse tanks, and the intermediate and final rinse tanks. The plating tank is filled to a predetermined level with a plating solution including plating chemicals and water. The rinse tanks are each filled to the predetermined level with rinse solution including water and plating chemicals which have been rinsed from preceding workpieces. The final rinse tank has an overflow outlet at the predetermined level and receives a continuous flow of water. As water evaporates from the plating tank, rinse solution flows by gravity through the connecting weir to the plating tank to replace it. Similarly, rinse solution flows by gravity through the connecting weir from the intermediate rinse tank to the first rinse tank and flows by gravity through the connecting weir from the final rinse tank to the intermediate rinse tank. The continuous flow of water into the final rinse tank replaces the solution flowing by gravity to the intermediate rinse tank thus maintaining the plating and rinse tanks at the predetermined level. To prevent plating chemicals from migrating from more concentrated solutions to less concentrated solutions, baffles are placed in each of the weirs. The baffles render the flow paths sufficiently long and tortuous so that the evaporation replacing flow offsets the migration of plating chemicals toward less concentrated solutions. |
