JP2000271550A - Cleaning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an electrolyte from remaining on the surface of an article after cleaning when acidic water or alkaline water obtained by electrolyzing water is used as cleaning water. SOLUTION: In this cleaning device, an electrolyte is added to an untreated water and this water is electrolyzed to modify the untreated water. The addition of the electrolyte to the untreated water is realized by dissolving a water-soluble gas into the untreated water. In this case, a carbon dioxide is, for example, used as the water-soluble gas. Further, it is desirable that the gas is added to the untreated water through a membrane-like separating means 11 with micropores.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning apparatus, and more particularly to a cleaning apparatus for cleaning articles using acidic water or alkaline water obtained by electrolyzing water without using a detergent or the like.

[0002]

2. Description of the Related Art For example, in a cleaning apparatus for cleaning an article such as a machine part or a workpiece during a manufacturing process of a semiconductor or a display device, a surfactant, an acid, an alkali, a peroxide or the like is generally used. Cleaning was performed using water to which the chemical was added. In recent years, in addition to the above method, acidic water or alkaline water obtained by modifying pH or oxidation-reduction potential by electrolysis has been used as washing water.

[0003]

However, of the above methods, the method involving the addition of a chemical has a problem that the chemical remains on the washed article and a problem that costs are required for environmental protection. .

On the other hand, in the electrolysis method, if tap water or the like is directly electrolyzed, there is a problem that a large amount of electric power is required to obtain desired acidic water or alkaline water. Also, in order to reduce the voltage required for electrolysis,
When an electrolyte such as salt is added, the electrolyte remains on the washed article, which causes a new problem that the article is corroded. In particular, when used for cleaning a workpiece during a semiconductor manufacturing process, there is a problem that the residual sodium and potassium ions in the electrolyte directly affect the yield of the device, and the quality of the product is reduced.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is directed to a cleaning apparatus in which an electrolyte is added to raw water and the raw water is reformed by electrolysis. The addition of the electrolyte to the raw water,
It is performed by dissolving a water-soluble gas in the raw water.

For example, carbon dioxide is used as the gas. Further, it is desirable that the gas be added to the raw water through a membrane-like separation means having fine pores.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of the configuration of the cleaning apparatus according to the present invention. This cleaning device includes a gas dissolving vessel 1
, An electrolytic cell 2 and a cleaning means 3.

The gas dissolving vessel 1 is divided into an upper water vessel 12 and a lower gas vessel 13 by a membrane-like separating material (membrane separating means) 11 having a large number of micropores. I have. Here, a material that selectively allows gas to pass through the micropores without passing water is used as the separation material 11. Further, a water supply channel 14 is formed at an upper end portion of the water container 12, and a drainage channel 15 is formed at a lower end portion, respectively.
A gas supply path 16 is formed at the center of the lower end of the gas container 13.

The electrolytic cell 2 is divided into an anode chamber 22 and a cathode chamber 23 by an ion-exchangeable and ion-permeable diaphragm 21. The anode chamber 22 and the cathode chamber 23 are connected to a water supply passage 24.
Is connected to the drainage channel 15. Electrodes 22a and 23a are installed in the anode chamber 22 and the cathode chamber 23, respectively. The electrode 22a is connected to an anode of a power supply (not shown) via a conductor 22b, and the electrode 23a is connected to the power supply via a conductor 23b. It is connected to the cathode of the device, the housing of the device or the ground terminal. Reference numerals 22c, 23
“c” denotes a cleaning water supply path for supplying the cleaning means 3 with the acidic water (described later) obtained in the anode chamber 22 and the alkaline water (described below) obtained in the cathode chamber 23, respectively.

Water (raw water) used for washing is supplied to the water supply channel 1.
4 to the water container 12 and stored in the water container 12. On the other hand, a gas that is dissolved in water to form electrolyte ions is supplied to the gas container 13 from the gas supply path 16.
This gas is pressurized in the gas container 13, passes through the separating material 11, and is extruded toward the water container 12, forms fine bubbles, rises in the water container 12, and is mixed with water in the water container 12. Dissolve. As a result, the electrolyte is added to the water in the water container 12, and the conductivity of the water increases.

The gas supplied from the gas supply passage 16 is preferably, for example, carbon dioxide, ammonia, hydrogen chloride or the like, but other gases may be used. FIG. 2 illustrates the relationship between the gas aeration time and the conductivity of water (pure water) when carbon dioxide is used as the gas. As is clear from FIG. 2, the conductivity of the water increases with the gas aeration time. Also, in order to extend the gas aeration time,
As shown in FIG. 1, it is preferable that the separating material 11 is provided below the water container 12, and the gas that has passed through the separating material 11 becomes fine bubbles and rises inside the water container 12.

The water in which the gas is dissolved is supplied to the anode chamber 22 and the cathode chamber 23 of the electrolytic cell 2 through the drain 15 and the water supply channel 24. Then, when an electric current is passed between the electrodes 22a and 23a through the conductive wires 22b and 23b, water in the electrolytic cell 2 is electrolyzed and electrophoresed on the electrodes 22a and 23a side. It is desirable to use a DC current or a pulse current as a current passed between the electrodes 22a and 23a.

As a result of the electrolysis and electrophoresis, the anode compartment 22
To the side, water (acidic water) whose pH is tilted to the acidic side and the oxidation-reduction potential is increased moves, and water (acidic water) whose pH is tilted to the alkaline side and the oxidation-reduction potential is lowered is moved to the cathode chamber 23 side. Move). These reformed waters are supplied to the cleaning means 3 individually or in a time series manner or simultaneously through the cleaning water supply passages 22c and 23c as necessary.
Used for cleaning articles.

The cleaning means 3 cleans the articles by immersing the articles in the above-mentioned acidic water or alkaline water and applying ultrasonic vibration. For example, when cleaning a silicon wafer, the acidic water or alkaline water is sprayed toward the wafer surface while rotating the wafer to dissolve and remove the deposits on the wafer surface. In this case, acidic water is effective for dissolving and removing metal ions, and alkaline water is effective for dissolving and removing organic substances.

Moreover, in the case of the present invention, since the electrolyte to be added is a gas, it is volatilized with the drying of the article after washing and does not remain on the surface of the article. Therefore, according to the present invention, it is possible to prevent the electrolyte from remaining on the surface of the article after cleaning, and to prevent the quality of the article from being reduced.

[0016]

According to the cleaning apparatus of the present invention, the following effects can be obtained because the acidic water or the alkaline water obtained by electrolyzing water is used for the cleaning water. (1) Since the oxidation-reduction potential can be modified in addition to the adjustment of the pH, the washing effect is higher than that of washing water prepared by simply adding a chemical. (2) Since electricity is supplied after the conductivity of water is increased by the addition of an electrolyte, the voltage required for electrolysis is lower than in the case where raw water is directly electrolyzed. Further, according to the cleaning device of the present invention, since the electrolyte to be added is a gas, the following effects can be obtained. (3) Since the electrolyte after washing volatilizes with drying of the article and does not remain on the surface of the article, deterioration of the quality of the article due to the remaining electrolyte is prevented.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a configuration of a cleaning device according to the present invention.

FIG. 2 is a diagram showing the relationship between the aeration time of carbon dioxide to water and the conductivity of water.

[Explanation of symbols]

 11 Separation material (membrane separation means)

Claims (2)

[Claims] 1. A washing apparatus in which an electrolyte is added to raw water and the raw water is reformed by electrolysis, wherein the addition of the electrolyte to the raw water is water-soluble in the raw water. A cleaning device, wherein the cleaning is performed by dissolving a gas. 2. The cleaning apparatus according to claim 1, wherein carbon dioxide is used as the gas, and the gas is added to the raw water through a membrane-like separation means having fine pores.