Dilute chemical solution production device

Abstract

A dilute chemical solution production device (1) comprises a chemical solution storage tank (2), a plunger pump (4) supplying a chemical solution S from the chemical solution storage tank (2), and a chemical solution supply tube (3). A chemical solution supply means (5) for supplementing the chemical solution S to the chemical solution storage tank (2) and a purge gas supply means (6) for supplying N2 gas as a purge gas to the chemical solution storage tank (2) are in communication with the chemical solution storage tank (2), which is provided with a first manometer (7) serving as a pressure measurement means. A drain tubing (8) is connected to the head section of the plunger pump (4), and an automatically controlled air bleed valve (9), which is an air bleeding mechanism, is installed onthe drain tubing (8). A second manometer (10) is installed on the chemical solution supply tube (3), and the end of the solution supply tube (3) on the downstream side serves as an injection point (11) for the chemical solution S. This dilute chemical solution production device enables stable production of a dilute chemical solution with an extremely low concentration of acid, alkali, or the like,with a simple structure.

Description

technical field [0001] The present invention relates to a dilute chemical solution manufacturing device, and in particular to a dilute chemical solution capable of producing extremely low concentrations of acids and alkalis effective in washing and rinsing processes of semiconductor wafers, etc., with a simple structure. A dilute liquid medicine manufacturing device for liquid medicine. Background technique [0002] In the manufacturing process of semiconductor wafers or liquid crystals, ultrapure water from which impurities have been removed to a high degree is used for washing semiconductor wafers or glass substrates. [0003] In semiconductor wafer cleaning using such ultrapure water, since such ultrapure water has a high resistivity value, static electricity is likely to be generated, and there is a risk of electrostatic breakdown of the insulating film and reattachment of fine particles. Therefore, water in which a solute effective for controlling pH and oxidation-redu...

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Problems solved by technology

[0011] However, the dilute drug solution manufacturing device described in the above-mentioned Patent Document 1 has the following problem: since it controls the pressure in the tank storing the drug solution and uses this pressure to push out a small amount of the drug solution to supply it, it must Separately measure the flow rate of ultrapure water, the concentration of the chemical solution, and the pressure in the tank where the chemical solution is stored, and perform fine pressure control so that the concentration of the diluted chemical solution becomes a predetermined value, which complicates the structure of the device

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