JP2003311140A - Apparatus for addition control of ultra small amount of liquid and gas-dissolved water production apparatus and gas-dissolved water production method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus having a simple structure and capable of continuously adding a high concentration solution at an extremely low flow rate; an apparatus comprising the former apparatus for producing ultrapure water in which a gas is dissolved by dissolving the chemical liquid; and a method for producing ultrapure water in which a gas is dissolved by dissolving the chemical liquid. <P>SOLUTION: The ultra small amount addition control apparatus is for continuously supplying an aqueous solution containing an electrolyte to continuously flowing ultrapure water and comprises a thin pipe equipped with a valve and connecting an apparatus for supplying the aqueous solution containing the electrolyte with a water flow pipe of the ultrapure water so as to control the supply amount by opening or closing the valve. The gas-dissolved water production apparatus comprises the ultra small amount addition control apparatus and an apparatus for obtaining ultrapure water containing a reducing or oxidizing gas by dissolving the reducing or oxidizing gas in ultrapure water. The gas-dissolved water production is carried out using the gas-dissolved water production apparatus. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling a minute flow rate with cleaning water for electronic materials and the like, and a gas dissolving apparatus for ultrapure water in which an electrolyte is dissolved using the apparatus.

[0002]

2. Description of the Related Art Recently, it has been found that water obtained by slightly adding gas components or chemicals to ultrapure water has a function of removing impurities on the surface of a wafer. Is getting attention because it has the same cleaning effect.
An example of using water containing a slight amount of gas components or chemicals as washing water is disclosed in Japanese Patent Laid-Open No. 2000-208471.
As disclosed in Japanese Patent Laid-Open Publication No. JP-A-2003-264, there has been proposed an adjusting device for electronic material cleaning water, which has a supply device for controlling a supply amount of an acid or an alkali based on electric conductivity and adjusting a supply amount, which will be described later. This method excels in precise concentration control, but may cause concentration hunting when flow rate fluctuations occur in ultrapure water during actual use.

The above-mentioned chemical liquid supply device is one in which a stock solution is once diluted to a certain extent and stored in a device tank and added to it. In applications such as semiconductor manufacturing equipment where metal ions are extremely disliked, a minute flow controller is connected. Since it is not possible to fabricate a minute flow meter or a minute flow rate control valve because the liquid part material needs to be a synthetic resin, it is not possible to add a high-concentration stock solution as it is. Therefore, the diluted chemical liquid for adjustment is used. Therefore, the density adjustment is delayed, and density hunting is likely to occur.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a device having a simple structure and capable of continuously adding a minute flow rate from a high-concentration solution, an apparatus for producing gas-dissolved ultrapure water in which a chemical solution incorporating the same is dissolved, and It is to provide the production of dissolved gas-dissolved ultrapure water.

[0005]

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that it is possible to easily control the addition of a minute amount by using a thin tube, and based on this finding, The invention was completed.

That is, the present invention is an apparatus for continuously supplying an aqueous solution in which an electrolyte is dissolved to continuously flowing ultrapure water, in which an apparatus for supplying an aqueous solution in which an electrolyte is dissolved and an ultrapure water flow pipe are provided. There is provided a minute addition amount control device in which a thin tube provided with a valve is connected between and, and the supply amount is controlled by opening and closing the valve.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The minute flow rate control device of the present invention is configured such that a flow pipe through which ultrapure water continuously flows and an aqueous solution supply device in which an electrolyte is dissolved are connected to a thin pipe provided with a valve, and the valve is opened and closed. Is to control the supply amount. Here, the supply amount of the aqueous solution in which the electrolyte is dissolved can be adjusted by increasing or decreasing the number of the valve-opened thin tubes.

At this time, the valves attached to the thin tubes may be installed in each of the thin tubes to be installed, or several thin tubes to be installed may be collected and the flow rate may be controlled by one valve.

There is no particular limitation on the method for connecting a plurality of the thin tubes in parallel, but for example, 1, 2,
4,8, ..., it can be arranged to provide a valve for each ^{2 n} present. In this case, the flow rate ratio of the bundle of thin tubes provided with the valve is 1: 2 :.
4: 8 ... and the flow rate can be changed in 2 ⁿ steps. If the number (n) of thin tube bundles is increased, the more delicate addition control becomes possible. There is no particular limit to the number of thin tubes,
Practically, it is composed of 1 to 1000, and more preferably 1 to 100. For example, FIG. 2 shows an example thereof.

The diameter of the thin tube is not particularly limited, but from the viewpoint of controlling the minute flow rate, the inner diameter is preferably 10
〜1000μm, more preferably 50 ~ 500μ inner diameter
m. As such a thin tube, a thin tube having a hollow fiber structure is preferable. As the hollow fiber structure, any of a so-called sandwich membrane in which a thin film such as urethane is sandwiched between layers such as a microporous membrane, a homogeneous membrane, a heterogeneous membrane, a composite membrane, and a polypropylene microporous membrane can be used.

The material of the thin tube is not particularly limited as long as it is other than metal in the case of cleaning for electronic materials, but it is preferably resistant to an aqueous solution in which an electrolyte is dissolved. For example, polyethylene resin, polypropylene resin, polytetrafluoroethylene, perfluoroalkoxy fluororesin,
Materials such as various fluororesins such as polyhexafluoropropylene, polybutene-based resins, silicone-based resins, poly (4-methylpentene-1) -based resins, and the like are preferable. Among them, poly (4-methylpentene-1) -based resin is particularly preferable.

The actual hollow fiber conduit may not have a strictly circular cross section, or the conduit cross-sectional area may not be constant. Therefore, it is preferable to prepare a hollow fiber having a length calculated from the following formula (4), obtain a flow coefficient by an actual flow test, and accurately calculate and adjust a necessary length. For example, in the formula (4), since the length of the conduit is proportional to the fourth power of the diameter of the conduit, if the diameter of the conduit differs by 10%, the length of the conduit differs by 46.4%.

The fine flow rate control device using a thin tube used in the present invention relates to Hagen-Pois regarding the head loss of laminar flow in a circular pipe.
It is an application of elle's law. The loss head H of the liquid flowing through the circular conduit can be expressed by the equation (1) in the case of laminar flow, and the length of the circular conduit can be obtained by modifying the equation (1) to the equation (4). It is represented by. FIG. 1 shows a schematic diagram when flowing through a thin tube.

[0014]

[Equation 1]

The meanings and units of the symbols in the above formulas (1) to (4) are as shown in Table 1 below.

[0016]

[Table 1]

When the flow rate / viscosity of the fluid, the diameter of the circular pipe, and the differential pressure at both ends of the circular pipe are known, the length L of the circular pipe is L.
Can be calculated from this formula.

From the above equation (5), it is possible to design a thin tube (optimal thin tube length, inner diameter, number) to obtain a desired minute flow rate.

When a minute flow rate is added using a thin tube in a cleaning device for electronic materials, etc., it is added to the ultrapure water that continuously flows. At this time, it is necessary to control the minute flow rate addition amount according to the change of the ultrapure water, for example, the change of the flow rate and the pressure to stably control the electrolyte concentration. For this purpose, a thin tube provided with a valve may be used to open and close the valve according to the change. Even if the change in ultrapure water is not measured, if the change in ultrapure water is within a certain range, stable control can be performed within a certain concentration range by using the thin tube of the present invention. That is, the electrolyte concentration can be controlled to a concentration within a practical range having a cleaning ability without feedback.

Further, if the change of ultrapure water is measured and controlled by this, the concentration can be controlled more strictly. At this time, various methods can be used to measure the change in the ultrapure water. For example, a method of measuring the flow rate of the ultrapure water with various flowmeters or the water quality of the ultrapure water is determined by an electrochemical constant. It can be performed by a method of measuring using. There are no particular restrictions on the various flow meters, but there are Karman vortex flow meters, ultrasonic flow meters, and the like. The method for measuring the electrochemical constant is not particularly limited, but examples thereof include an electric conductivity meter, a PH meter, a resistivity meter, an ORP meter, and an ion electrode meter.

Further, the ratio of the supply amount (X) of the aqueous solution in which the electrolyte is dissolved and the flow rate of the ultrapure water (Y) which flows continuously is (X) / (Y) = 1 / 1,000,000 to 1/1000. Is preferred. Considering that it also dissolves gas,
(X) / (Y) = 1 / 100,000 to 1 / 10,000 is more preferable.

The electrolyte concentration in the ultrapure water supplied with the aqueous solution in which the electrolyte is dissolved is preferably 0.00001 to 0.1% by weight. Further, considering that gas is dissolved, the electrolyte concentration in the ultrapure water is more preferably 0.0001 to 0.01% by weight.

Further, the supply amount of the aqueous solution in which the electrolyte is dissolved is
When it is 0.001 to 10 cm ³ , the method using this thin tube is particularly effective. That is, since there is no flow meter or regulating valve for controlling a minute flow rate that is used in a semiconductor manufacturing apparatus, the method using this thin tube is particularly useful in this field.

The aqueous solution in which the electrolyte used in the present invention is dissolved is not particularly limited, and examples thereof include acids such as hydrochloric acid, sulfuric acid, hydrogen fluoride, nitric acid and carbonic acid, and alkalis such as ammonia, potassium hydroxide and sodium hydroxide. To be

Next, the apparatus for producing gas-dissolved water according to the present invention,
An apparatus for obtaining an ultrapure water to which an electrolyte is added by adding an aqueous solution in which an electrolyte is dissolved in ultrapure water, and a reducing or oxidizing gas is dissolved in the ultrapure water to reduce a reducing or oxidizing gas. This is a gas-dissolved water production apparatus combined with an apparatus for obtaining dissolved ultrapure water. That is, the present invention provides an apparatus for controlling pH in ultrapure water and efficiently producing water having an oxidizing property or a reducing property and having an excellent cleaning effect with a simple mechanism. For that purpose, an apparatus for obtaining ultrapure water in which a reducing or oxidizing gas is dissolved is preferably an apparatus for dissolving the gas in ultrapure water through a gas permeable membrane.

The reducing gas or oxidizing gas is not particularly limited, but examples thereof include hydrogen, oxygen and ozone.

There are various methods for dissolving the reducing gas or the oxidizing gas in ultrapure water, including a method using an ejector and a gas permeable membrane. Above all, a method using a gas permeable membrane is an effective method for efficiently dissolving gas.

The gas permeable membrane used in the present invention is not particularly limited in material, structure and morphology as long as it has a high gas permeation rate, but the membrane material is preferably a highly hydrophobic material.
For example, polyethylene resin, polypropylene resin,
Preferable examples include various fluororesins such as polytetrafluoroethylene, perfluoroalkoxy fluororesins, polyhexafluoropropylene, polybutene-based resins, silicone-based resins, poly (4-methylpentene-1) -based resins, and the like. As the membrane structure, a so-called sandwich membrane in which a thin film such as urethane is sandwiched between layers such as a microporous membrane, a homogeneous membrane, a heterogeneous membrane, a composite membrane, and a polypropylene microporous membrane can be used. Examples of the form of the membrane include a flat membrane and a hollow fiber membrane, and the hollow fiber membrane is preferable in terms of gas dissolution efficiency.

The gas permeation rate of the hollow fiber membrane is 1 × 10 −6.
[Cm ³ / cm ² · sec · cmHg] (= 7.5 × 10 ^-12 [m ³ / m ² ·
sec ・ Pa]) or more, 10 ^-2 [cm ³ / cm ²・ sec ・ cmHg]
It is preferably (= 7.5 × 10 ⁻⁹ [m ³ / m ² · sec · Pa]) or less. 1 x 10-6 [cm3 / cm2 ・ sec ・ cmH
If it is less than g] (= 7.5 × 10 ⁻¹² [m3 / m2 · sec · Pa]), the gas permeation rate through the hollow fiber membrane will be slow, and the target concentration will not be reached or ultrapure water will be obtained. The concentration changes when the flow rate changes. Also, 10 ^-2 [cm3 / cm2 ・ sec ・
In the case of a hollow fiber membrane exceeding cmHg] (= 7.5 × 10 ⁻⁹ [m ³ / m ² · sec · Pa]), there is a problem that ultrapure water permeates to the gas side.

The hollow fiber heterogeneous membrane made of poly (4-methylpentene-1) resin used in the present invention is most preferable because it has excellent gas permeability and high water vapor barrier property. Regarding the heterogeneous film used in the present invention, for example, Japanese Patent Publication No. 2-38250, Japanese Patent Publication No. 2-54377,
The details are described in Japanese Patent Publication No. 4-15014, Japanese Patent Publication No. 4-50053, and the like.

Materials such as polyethylene resin, polypropylene resin and polyvinylidene fluoride resin have low gas permeability. Therefore, for application to gas dissolution applications, a microporous structure is adopted, and gas is permeable through the porous portion. Compared to these membranes that have to be forced, this heterogeneous membrane made of poly (4-methylpentene-1) resin has sufficiently high gas permeability and the dense layer has a sufficient thickness. Very thin, the entire membrane surface can contribute to gas permeation, and as a result, the substantial membrane area becomes large, which is extremely preferable.

As for the housing in which the hollow fiber membrane is disposed, any material may be used as long as it does not elute impurities into the ultrapure water. For example, polyolefins such as polyethylene, polypropylene and poly 4-methylpentene 1, fluorine-based materials such as polyvinylidene fluoride and polytetrafluoroethylene, engineering plastics such as polyether ether ketone, polyether ketone, polyether sulfone and polysulfone. Alternatively, a clean vinyl chloride type, which is used as a piping material for ultrapure water because of its low elution, can be used.

As a hollow fiber membrane module structure, a plurality of hollow fiber membranes are converged and arranged in a housing, gas is supplied to the space between the outside of the hollow fiber membranes and the housing, and the inside of the hollow fiber membranes is supplied. In addition to the internal perfusion type in which ultrapure water is flown, an external perfusion type in which ultrapure water is flown outside the hollow fiber and gas is flown inside is disclosed in Japanese Patent Publication No. 5-21841.

In the case of the external perfusion type, in order to prevent uneven flow (channeling) of water due to uneven filling of the hollow fibers in the housing, the hollow fibers are hollow fibers or other yarns or other yarns. It is effective to form a sheet-like material, for example, a sheet-like material, which is formed into a blind shape by using, and to incorporate it into the housing in the state of a superposed body, a wound body, and a converging body. It is also possible to adopt an appropriate shape such as incorporating a three-dimensional structure in which the hollow fiber is wound around a cylindrical core.

Either the internal perfusion or the external perfusion may be adopted for either structure in order to dissolve the gas in ultrapure water.

Although the gas-dissolved water producing device and the device for adding the aqueous solution in which the electrolyte is dissolved are independent devices, whichever device may be located first.

That is, the gas may be dissolved after adding the aqueous solution in which the electrolyte is dissolved in ultrapure water, or conversely, the aqueous solution in which the electrolyte is dissolved may be added after dissolving the gas in ultrapure water. . However, in order that the aqueous solution in which the electrolyte is dissolved diffuses into the ultrapure water and becomes a uniform concentration state, it is more preferable to dissolve the gas after adding the aqueous solution in which the electrolyte is dissolved in the ultrapure water. In this case, for example, if a gas permeable membrane is used for gas dissolution, the water is sufficiently agitated like a static mixer while passing through the gas permeable membrane. Needless to say, the position of the device does not matter if a sufficient flow path is secured. An example of the configuration of the device is as shown in FIG.

The present invention will be described in more detail below with reference to examples and comparative examples. However, the present invention is not limited to this and is not limited.

Raw water is 18.2 MΩ · c at 25 ° C.
Ultrapure water having a specific resistance of m was used. The flow rate maintenance time was changed stepwise at 1 minute. The supply water pressure is 0.20M
Pa · G (= 2 kgf / cm ² · G).

Example 1 Consider an apparatus for dissolving a 29% aqueous ammonia solution as an aqueous solution in which an electrolyte is dissolved. First, the length of the thin tube used for this is calculated. Design a thin tube of a device for adding a 29 wt% aqueous ammonia solution to ultrapure water to make a 6 mg / liter aqueous ammonia solution. The physical properties of the 29 wt% aqueous ammonia solution are as follows. γ (specific gravity) = 0.900, μ (viscosity) = 1.0 × 10 ^-3 P
a ・ s (1.0 cP), flow rate of 29 wt% NH ₃ aqueous solution when the NH ₃ concentration is 6 ppm with respect to ultrapure water flow rate 1 liter / min (10 kg / min)
Is 1 × 10 ³ × 6 × 10 ^-6 ÷ 0.29 = 0.0207 g / min = 0.207 ÷
0.900 = is 0.0230 cm ³ / min. Next, the length L when the pressure difference ΔP = 0.05 Mpa before and after the thin tube and the capillary inner diameter D = 0.100 mm is obtained. The following equation (6) is derived from the above equation (5).

[0041]

[Equation 2]

By transforming the above equation (6) so that the practical unit shown in Table 2 can be used, the equation (7) is derived. The symbols and units in the formulas (6) and (7) are those shown in Table 2 below.

[0043]

[Equation 3]

[0044]

[Table 2]

Here, D = 0.001, ΔP = 0.0
Substituting 5, μ = 1.0 and Q = 0.0230, L =
1,473,000 × 0.100 ⁴ × 0.05 ÷ 1.0 ÷ 0.0230 = 320
mm, and the length (L) of the circular conduit may be 320 mm.

In order to compare the calculated value and the measured value of the flow rate through the hollow fiber, four poly 4-methylpentene 1 hollow fibers having a diameter of 0.1 mm and a length of 300 mm were arranged in parallel and pure water was flowed. The flow rate was measured.

The differential pressure (ΔP) is 0.05 to 0.15 MPa
I changed it. Flow rate error with calculated value is 17-27%
Met. From this result, it can be seen that the error in diameter is only 6% even if it is assumed that the cause of the error is due to the error in the diameter of the hollow fiber. Judging from this result, it was found that the hollow fiber can be sufficiently used as an element of the minute flow rate control device.

Next, using a poly 4-methylpentene 1 hollow fiber having a diameter of 0.1 mm and a length of 300 mm, a micro-addition device having two yarn bundles was prepared. As a result, 29 wt% ammonia water was added to the ultrapure water. An attempt was made to prepare ultrapure water having a pH of 10 with a small amount of addition. Ultra pure water flow rate is water pressure 0.2M
Pa · G 0.5 to 9 liters / minute in a stepwise manner up to 0.5
Increase / decrease in liters / minute. The flow rate maintenance time was changed stepwise at 1 minute. Ammonia was added with the valve opened without controlling the flow rate of ultrapure water. Moreover, when adding ammonia, it pressurized at 0.25 MPa * G.

The ammonia concentration of the obtained ammonia-added ultrapure water was measured with a pH meter. As a result, the following table was obtained, and it was found that an aqueous ammonia solution having a stable pH concentration was obtained regardless of the flow rate of ultrapure water.

[0050]

[Table 3]

Comparative Example 1 As in Example 1, an aqueous solution in which an electrolyte was dissolved was used as 29
Consider a device that dissolves a% ammonia solution. For piping
Calculate the required length when a tube for use is used. Ultrapure water
29 wt% aqueous ammonia solution was added to
600 mg / liter of ammonia water, which is 100 times the concentration
Design the capillaries of the device for making the solution. 29wt% Ammo
The physical properties of the near aqueous solution are as follows. γ (specific gravity) = 0.900, μ (viscosity) = 1.0 x 10^-3Pa · s
(1.0cP) NH3 for ultra pure water flow rate of 1 liter / min (= 10kg / min)₃Dark
29wt% NH at 600ppm ₃Flow rate of aqueous solution Q = 1 × 10³× 60
0 x 10^-6÷ 0.29 ＝ 2.07g / min ＝ 2.07 ÷ 0.900 ＝ 2.30cm³/ m
in, differential pressure before and after thin tube ΔP = 0.01 MPa, tube inner diameter D = 5 mm
Then, find the length L. From the above formula (1),
Equation (8) is derived.

[0052]

[Equation 4]

When the above formula (8) is modified so that the practical units shown in the table below can be used, the following formula (9) is derived.

[0054]

[Equation 5]

Next, ΔP = 0.01 MPa, tube inner diameter D = 5 m
Substituting m, Q = 2.30 cm ^{3 /} min, µ = 1.0 cP, and finding the required length (L) when using a general-purpose tube for piping,
L = 1,473,000 x 5 ⁴ x 0.01 ÷ 1.0 ÷ 2.3 = 4 x 10 ⁶
Since mm = 4000 m, it is practically impossible to manufacture a trace amount addition device for adding ammonia in such a pipe length in a compact manner.

If the same ammonia concentration as in Example 1 is to be obtained, the calculation is performed in the same manner as described above, and it is 10
A pipe length of 0 times and 400 km are required, and even in this case, it cannot be practically used.

On the other hand, if the differential pressure before and after the piping is 1/100 times 0.01 MPa, the length will be 40 m, but the ammonia addition amount could not be controlled with such a small differential pressure.
Further, when the pressure change of the ultrapure water occurs, the ultrapure water may flow back into the aqueous ammonia solution and cannot be used.

Example 2 As in the case of Example 1, a minute flow rate addition device as shown in FIG. 2 was prepared using hollow fibers.

Flow coefficient (unit cm ³ / min / MPa)
The hollow fibers were bundled in three sets of 1, 2, and 4 hollow fibers so that the hollow fibers were 0.5, 1.0, and 2.0. This bundle is connected in parallel and the differential pressure is 0.05
When adding MPa and controlling each with an ON-OFF valve,
0, 0.025, 0.05, 0.075, 0.10, 0.125, 0.15, 0.175 cm
As an example, it is possible to flow ³ / min.

[0060]

[Table 4]

When this is used, if the pure water flow rate is measured and the valves AV-1, 2 and 3 are opened / closed according to the pure water flow rate, it is not possible to make a perfect proportion, but it is almost proportional to the flow quantity. A small amount of wt% ammonia water can be added to pure water.

Next, a poly 4-having a diameter of 0.1 mm and a length of 300 mm is used.
Methyl pentene 1 Hollow fiber, 1, 2, 4 3
A set of hollow fiber bundles was made into a micro addition device. As a result, 29 wt% ammonia water was added to the ultrapure water while changing the flow rate of the ultrapure water. An attempt was made to prepare ultrapure water having a pH of 10 with a small amount of addition. The flow rate of ultrapure water is 0.2 MPa
G was stepwise increased or decreased in 0.5 liters / minute from 0.5 to 9 liters / minute. The flow rate maintenance time was changed stepwise at 1 minute. The amount of ammonia added was controlled by measuring the flow rate of ultrapure water after addition of ammonia and opening / closing the hollow fiber valve accordingly. Moreover, when adding ammonia, it pressurized at 0.25 MPa * G.

The ammonia concentration of the obtained ultrapure water containing ammonia was measured with a PH meter. As a result, the results are shown in Table 5 below, and it was found that an ammonia aqueous solution having a stable concentration was obtained regardless of the flow rate of ultrapure water.

[0064]

[Table 5]

Example 3 Ammonia was added using the minute addition amount apparatus of Example 1. Thereafter, as shown in FIG. 3, the gas was dissolved using a gas permeable membrane. The hollow fiber membrane module is made of poly-4-methylpentene-1 and has an inner diameter of 100 μm and an outer diameter of 1
2m2 by converging the 80μm thread and fixing both ends of the thread with resin in the polypropylene resin housing.
Externally perfused hollow fiber module for gas supply with membrane area (SEPAREL E manufactured by Dainippon Ink and Chemicals, Inc.)
F-002A) was obtained. Oxygen permeation rate of hollow fiber membrane is 1 ×
10 ⁻⁵ [cm ³ / cm ² · sec · cmHg] (= 0.7 × 10
^-9 [m ³ / m ² · sec · Pa]).

Using this, hydrogen gas was dissolved in ultrapure water to which an aqueous ammonia solution was added. Hydrogen gas is 99.9
% Purity gas was used, the gas pressure was supplied at 0.02 MPa · G, and the gas was exhausted at the flow rate of 500 cm ³ / min at the module outlet side. After leaving the module, the dissolved hydrogen concentration was measured using a dissolved hydrogen meter (DH-35A manufactured by Toa DKK Co., Ltd.). As a result, at a flow rate of ultrapure water of 0.5 to 9 liters / minute,
Ultrapure water having a stable dissolved hydrogen concentration of 1.4 to 1.6 mg / liter was obtained.

[0067]

INDUSTRIAL APPLICABILITY The present invention can be applied to ultrapure water that continuously flows,
It is intended to provide a minute addition amount control device in which an aqueous solution in which an electrolyte is dissolved is connected to a thin tube provided with a valve and the supply amount is controlled by opening and closing the valve. By using this,
It became possible to add a minute amount from a highly concentrated stock solution in one step. Further, ultra pure water in which the electrolyte and the gas were dissolved was stably obtained by a device including this and a gas dissolving device.

[Brief description of drawings]

FIG. 1 is a schematic diagram when a thin tube is connected to continuously flowing ultrapure water and an electrolyte is supplied according to the present invention.

FIG. 2 is a schematic diagram showing an example of a device for controlling the minute addition amount of a liquid according to the present invention.

FIG. 3 shows an example of a gas dissolving device for ultrapure water in which an electrolyte is dissolved according to the present invention.

[0068]

[Explanation of symbols]

1 Flow control valve 2 Micro addition device 3 gas dissolution equipment 4 Pressure control valve

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B01F 5/02 B01F 5/02 Z H01L 21/304 648 H01L 21/304 648G 648K (72) Inventor Koji Tomita 501-2-602 Konakadai, Inage-ku, Chiba Prefecture (72) Inventor Issei Sakai 4-19-3 Takanodai, Yotsukaido City, Chiba Prefecture (72) Inventor Naoki Haneda 3-5-1-2 Osakidai, Sakura City, Chiba Prefecture −203 (72) Inventor Katsuhiko Kazama 3-17-3-507 F Term 3-17-3-507 Masago, Mihama-ku, Chiba Prefecture (Reference) 4D006 GA35 KA31 KB30 MA01 MA03 MB03 MC22 MC23 MC28 MC30 MC65 PC80 4G035 AB05 AB37 AC01 AC18 AE02 AE13 4G037 AA02 BA01 BA03 BB06

Claims (12)

[Claims] 1. A device for continuously supplying an aqueous solution in which an electrolyte is dissolved to continuously flowing ultrapure water, wherein a device for supplying an aqueous solution in which the electrolyte is dissolved and a flow pipe for ultrapure water are provided. A micro addition amount control device which controls a supply amount by connecting a thin tube provided with a valve and opening and closing the valve. 2. The minute addition amount control device according to claim 1, wherein a plurality of the thin tubes are connected in parallel, and the supply amount is controlled by the number of opened valves. 3. The concentration of ultrapure water supplied with the aqueous solution in which the electrolyte is dissolved is controlled to be constant based on the change in the flow rate of the ultrapure water supplied with the aqueous solution in which the electrolyte is dissolved or the change in the electrochemical constant. Item 2. A minute addition amount control device according to item 2. 4. A supply amount (X) of an aqueous solution in which an electrolyte is dissolved
4. The minute addition amount control device according to claim 1, 2 or 3, wherein the ratio of the flow rate of the ultrapure water (Y) flowing continuously is (X) / (Y) = 1 / 1,000,000 to 1/1000. . 5. The minute addition amount control device according to claim 1, wherein the electrolyte concentration of the ultrapure water supplied with the aqueous solution in which the electrolyte is dissolved is 0.00001 to 0.1% by weight. 6. The supply amount of the aqueous solution in which the electrolyte is dissolved is 0.
The minute addition amount control device according to claim 1, which is 001 to 10 cm ³ / min. 7. A device (A) for continuously obtaining an ultrapure water added with an electrolyte by adding an aqueous solution in which an electrolyte is dissolved to continuously flowing ultrapure water and reducing or oxidizing the ultrapure water. (A)-(B) having an apparatus (B) for obtaining ultrapure water in which a reducing gas or an oxidizing gas is dissolved by dissolving a reactive gas Alternatively, the gas-dissolved water production apparatus connected in the order of (B)-(A), wherein the apparatus (A) for obtaining ultrapure water to which an electrolyte is added is according to any one of claims 1 to 6. An apparatus for producing gas-dissolved water, which uses a minute flow rate controller. 8. The apparatus (B) for obtaining ultrapure water in which a reducing or oxidizing gas is dissolved is an apparatus for dissolving the gas in ultrapure water via a gas permeable membrane. Gas dissolved water production equipment. 9. A step (a) of obtaining an ultrapure water to which an electrolyte is added by adding an aqueous solution in which an electrolyte is dissolved to continuously flowing ultrapure water, and a reducing or oxidizing gas for the ultrapure water. And (b) to obtain ultrapure water in which a reducing or oxidizing gas is dissolved by dissolving (a)-(b) or (a). b)-(a), which is a gas-dissolved water production apparatus connected in this order, wherein the electrolyte is dissolved in continuously flowing ultrapure water in the step (a) of obtaining ultrapure water to which the electrolyte is added. The process of supplying the aqueous solution
Production of gas-dissolved water characterized in that a thin tube provided with a valve is connected between a supply device for an aqueous solution in which an electrolyte is dissolved and a flow pipe for ultrapure water, and the supply amount is controlled by opening and closing the valve. Method. 10. The step (a) is an apparatus for continuously supplying an aqueous solution in which an electrolyte is dissolved to ultrapure water which is continuously flowing, the apparatus for supplying an aqueous solution in which the electrolyte is dissolved and the ultrapure water. The method for producing gas-dissolved water according to claim 9, wherein a fine pipe provided with a valve is connected to the flow pipe, and a minute addition amount control device that controls the supply amount by opening and closing the valve is used. 11. The micro addition amount control device controls the ultra pure water supplied with the aqueous solution in which the electrolyte is dissolved based on the change in the flow rate of the ultra pure water supplied in the aqueous solution in which the electrolyte is supplied or the change in the electrochemical constant. The method for producing gas-dissolved water according to claim 10, wherein the concentration is controlled to be constant. 12. The step (b) comprises:
The method for producing gas-dissolved water according to claim 11, which is an apparatus for dissolving the gas in ultrapure water.