| 摘要 |
PROBLEM TO BE SOLVED: To automatically dilute a heavily doped cleaning stock solution and deionized water without swallowing up bubbles in a diluted solution after mixing to adjust an extremely lightly doped cleaning liquid. SOLUTION: When injecting a heavily doped cleaning stock solution and deionized water into a mixing tank 2, two liquids are injected to a circulation line 17 through a check valve instead of being injected into the mixing tank directly, the return pipe of the circulation line in the mixing tank is extended down from the liquid level of the mixing tank, thus mixing the cleaning stock solution and the deionized water into the mixed liquid without generating any bubbles. When measuring the cleaning stock solution and the deionized water, they are measured by a metering pump 27 and a load cell 15, respectively as a main measurement monitoring means. As a sub measurement monitoring means, the cleaning stock solution and the deionized water are measured by the load cell and an oil level meter, respectively, for double-checking the measurement, thus achieving reliable dilution. COPYRIGHT: (C)2007,JPO&INPIT |
