JP2000153865A - Apparatus for supplying highly pure medicine and method for supplying highly pure medicine using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an apparatus for supplying highly pure medicine wherein a residual amount of the medicine can be known with an amount of particles in the medicine is kept at an extremely micro amount, and to obtain a method for supplying the medicine using the apparatus. SOLUTION: This apparatus for supplying highly pure medicine comprises a container body 1 made of stainless steel wherein an internal surface is electropolished and a lid 2 with a form which can be joined with the container body. The container body and/or the lid include a highly pure medicine inlet 3 for injecting highly pure medicine into the container body, a highly pure medicine supply port 5 for taking out the medicine of the container body, and at least an optical liquid level sensor 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-purity chemical supply apparatus and a high-purity chemical supply method using the same.

[0002]

2. Description of the Related Art Conventionally, stainless steel tanks having polished internal surfaces have been used as high-purity chemical supply devices and storage tanks. This is to reduce impurities by finishing the inner surface as precisely as possible. In other words, if the surface inside the tank is rough, particles (particles) such as dust adhere to the fine irregularities,
Even if the inside of the tank is washed, attached particles cannot be easily removed.

[0003] Therefore, the inside of a stainless steel container is electrolytically polished and mirror-finished to minimize the mixing of particles. For this reason, the remaining amount of the contents (high-purity chemicals) of the stainless steel container cannot be known. That is,
In ordinary tanks, etc., the remaining amount could be known by providing a glass window, etc., but the glass part could not be polished with high precision like electrolytic polishing stainless steel, and when the contents touched this glass part There is a problem that the amount of particles in the contents increases.

[0004]

In order to solve such a drawback, a high-purity chemical supply apparatus shown in FIG. 4 is currently used. The supply device for a high-purity chemical shown in FIG. 4 has a container body (1) made of stainless steel whose inner surface is electrolytically polished, and a lid that can be joined to the container body (1) with bolts and nuts (11). (2). The lid (2) is also made of stainless steel whose inner surface is electrolytically polished. The lid (2) is provided with a high-purity chemical injection port (3) for injecting the high-purity chemical (10), and by appropriately operating the injection valve (4), the container is opened. The main body (1) can be filled with a high-purity chemical. The lid (2) is provided with a high-purity chemical supply port (5) for appropriately supplying a high-purity chemical from inside the container body (1). The high-purity chemical is provided for use by appropriate operation.

When the high-purity chemical is used, if the high-purity chemical in the container body (1) is emptied and the supply of the high-purity chemical is interrupted, an adverse effect is exerted on a device using the high-purity chemical. In some cases, it may be necessary to stop the apparatus before the high-purity chemical in the container body (1) becomes empty or to switch to another high-purity chemical supply apparatus. For this reason, in the conventional high-purity chemical supply apparatus shown in FIG. 4, a float type liquid meter composed of a shaft (7) and a float (8) is provided, and the container body is provided by the float type liquid meter. When the remaining amount of the high-purity chemical in the unit (1) reaches a predetermined amount, a signal is sent out via the detector (9) to perform desired control. Here, the shaft (7) and the float (8) constituting the float type liquid meter are made of stainless steel whose surface is electrolytically polished, and a magnetic reed relay switch is incorporated in the shaft (7). A magnet is incorporated in (8), and the magnetic reed relay switch in the shaft (7) operates by the movement of the float (8) as the amount of high-purity chemical increases or decreases. However, due to the movement of the float (8) due to the increase or decrease in the amount of the high-purity chemical, the surface of the float (8) and the like is shaved due to mechanical contact between the float (8) and the shaft (7), and new particles are generated. However, there is a problem that high-purity chemicals are contaminated.

Japanese Patent Publication No. 9-508208 discloses a chemical replenishment system for high-purity chemicals, comprising a container having a float type liquid meter in which a float is coated with a fluororesin. However, even if the float is coated with a fluororesin, there is no difference in mechanical contact between the float and the shaft from the float type liquid meter, and it is not very effective in preventing generation of particles.

Accordingly, an object of the present invention is to provide a high-purity chemical supply apparatus capable of knowing the remaining amount of a high-purity chemical while keeping the amount of particles in the high-purity chemical at a very small amount, and a high-purity chemical supply apparatus using the same. It is to obtain a supply method.

[0008]

Means for Solving the Problems The present inventors have assiduously studied in view of the above, and have reached the present invention. That is, the present invention comprises a container body made of stainless steel whose inner surface is electrolytically polished, and a lid that can be joined to the container body, wherein the container body and / or the lid are the container. A high-purity medicine inlet for injecting the high-purity medicine into the main body, a high-purity medicine supply port for taking out the high-purity medicine from the container main body, and at least one optical liquid level sensor. It is in the characteristic high-purity chemical supply device.

Further, the present invention provides a step of injecting a high-purity chemical into the high-purity chemical supply apparatus from a high-purity chemical supply port of the high-purity chemical supply apparatus; Supplying the high-purity chemical from the apparatus; detecting the residual amount of the high-purity chemical in the high-purity chemical supply device by at least one optical liquid level sensor; And stopping the supply of the high-purity chemical on the basis of the high-purity chemical supply method.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A feature of the present invention is that a high-purity chemical supply apparatus comprising a stainless steel container body having an electropolished inner surface and a lid capable of being joined to the container body. In order to detect the remaining amount of the high-purity chemical in the container main body, an optical liquid level sensor is used.

An optical liquid level sensor usable in the present invention includes:
Emitting optical fiber and receiving optical fiber
A light detection probe unit having a prism unit having a plurality of internal reflection surfaces is provided in front of the front ends of the two optical fibers so as to allow light emitted from the light projecting optical fiber to enter the light receiving optical fiber.

FIG. 2 shows a light detection probe section of the optical liquid level sensor. In FIG. 2, a right-angle prism (18) having an internal reflection surface is provided at the distal end of the light-projecting optical fiber (16) and the light-receiving optical fiber (17) installed in parallel. Further, a protection tube (19) for protecting the light emitting optical fiber (16) and the light receiving optical fiber (17) is integrally formed with the right-angle prism (18) and can be made of fluororesin or the like.

The optical liquid level sensor provided with such a light detection probe section operates as follows. First, when the right-angle prism (18) of the light detection probe unit is not immersed in the high-purity chemical or is immersed only to a certain level, the light emitting optical fiber (16) is used.
Is reflected by the internal reflection surface of the right-angle prism (18), enters the light-receiving optical fiber (17), and is not scattered to the outside through the right-angle prism (1). When the intensity of the outgoing light and the intensity of the incident light are measured, the difference between the intensity of the outgoing light and the intensity of the incident light is small.

On the other hand, when the right-angle prism (18) is immersed in a high-purity chemical at a certain level or higher, most of the light emitted from the light-projecting optical fiber (16) is a right-angle prism (1). ) Through the inner reflective surface, and thus
The incident light reflected on the internal reflection surface of the right-angle prism (18) and entering the light receiving fiber (17) is almost eliminated. In this case, the emitted light travels through the high-purity chemical via the right-angle prism (18) and is scattered. Accordingly, the incident light that enters through the right-angle prism (18) is very weak, and when the intensity of the outgoing light and the incident light is detected, the difference between the intensity of the outgoing light and the intensity of the incident light increases. The surface is a right angle prism (1
8) It is possible to detect that it is above a certain level.

By the way, when an optical liquid level sensor having a photo-detecting probe having the structure shown in FIG. 2 is installed near the bottom of the container body, the light passes through the right-angle prism (18) and becomes high. The outgoing light traveling through the pure chemical may be reflected by the bottom of the container body and become incident light via the right-angle prism (18). In such a case, the difference between the intensity of the emitted light and the intensity of the incident light becomes small, and it may be difficult to detect the liquid level of the high-purity chemical. In such a case, the difference between the intensity of the outgoing light and the intensity of the incident light can be increased by using a light detection probe having a configuration as shown in FIG. That is, as shown in FIG. 3, the light emitting optical fiber (16) and the light receiving optical fiber (1) are used.
By making the distal end portions of 7) open forward, a certain angle is formed between the light emitting axis of the light projecting optical fiber (16) and the light incident axis of the light receiving optical fiber (17). A configuration is provided. When the light detection probe having such a configuration is installed near the bottom of the container body, even if the outgoing light transmitted through the conical prism (20) is reflected on the bottom surface, it is converted from the conical prism (20) as incident light. It is possible to prevent the incident light, and thus the intensity of the incident light can be made weaker. Therefore, when the intensity of the emitted light and the incident light is detected, the difference between the intensity of the emitted light and the incident light is reduced. Can be larger. That is, it is possible to more clearly determine that the liquid level of the high-purity chemical is above a certain level of the conical prism (20).

An optical liquid level sensor provided with a light detection probe unit as shown in FIGS. 2 and 3 is a light emitting optical fiber (16 made of a fluororesin) integrally formed with a prism at the tip. ) And the receiving optical fiber (17) are accommodated, and the optical liquid level sensor having such a configuration has no mechanical contact between the constituent members, and therefore does not generate new particles. Absent. Therefore, by monitoring the remaining amount of the high-purity chemical by installing the optical liquid level sensor having the above-described configuration at least at one place in the container body of the high-purity chemical supply device, the conventional float type It is possible to prevent the generation of new particles that are generated when the surface of the float etc. is shaved due to the mechanical contact between the float and the shaft due to the movement of the float due to the increase and decrease of the amount of high purity chemical which was a problem with the liquid meter. As a result, the chemicals in the container body can be maintained at a higher purity. An optical liquid level sensor having the above-described configuration is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-99729.

Further, in order to accurately install the light detecting probe portion of the optical liquid level sensor at a predetermined position near the bottom of the container body, a light emitting optical fiber (16) and a light receiving light are placed in a protective tube (19). It is also possible to insert a support rod (for example, a metal rod) together with the optical fiber (17) for use so as to maintain the shape of the optical liquid level sensor.

The high-purity chemical that can be supplied by the high-purity chemical supply device of the present invention is not particularly limited, and examples thereof include tetraethyl orthosilicate. Further, the apparatus for supplying the high-purity chemical by the high-purity chemical supply apparatus of the present invention is not particularly limited. For example, a CVD apparatus or the like can be exemplified.

Further, in the method of the present invention, the step of detecting the remaining amount of the high-purity chemical in the container body by at least one optical liquid level sensor, and the step of detecting the high-purity chemical based on the detected remaining amount of the high-purity chemical. A step of stopping the supply of the pure chemical. In the method of the present invention, by detecting the remaining amount of the high-purity chemical by the optical liquid level sensor, without generating new particles, while maintaining the purity of the high-purity chemical, the purity of the high-purity chemical in the container body is maintained. The supply of the high-purity chemical can be stopped according to the remaining amount.

[0020]

The apparatus and method of the present invention will be further described below with reference to examples. Embodiment One embodiment of the high-purity chemical supply apparatus of the present invention will be described with reference to FIG. In the high-purity chemical supply device shown in FIG. 1, the container body (1) and the lid (2) are both made of stainless steel whose inner surfaces are electrolytically polished. The lid (2) is shaped so that its flange can be joined in an airtight manner by joining means such as bolts and nuts (11). In addition, the shape of the container body (1) and the lid (2) is not particularly limited, and may be any shape depending on the use and the like.
Also, the method of joining the container body (1) and the lid (2) is not particularly limited, and any conventional means can be used.

The lid (2) contains a high-purity chemical (1).
A high-purity chemical injection port (3) for injecting the high-purity chemical is provided in the container body (1) by appropriately operating the injection valve (4). It has become. The lid (2) is provided with a high-purity chemical supply port (5) for appropriately supplying a high-purity chemical from inside the container body (1), and a supply valve (6).
The high-purity chemical is provided for use by appropriately operating. In the embodiment shown in FIG. 1, the high-purity chemical inlet (3) and the high-purity chemical supply port (5) are connected to the lid (2).
However, it can be appropriately installed in the container body (1) in consideration of the shape of the container body (1).

Further, the lid (2) is provided with an optical liquid level sensor (12). Optical liquid level sensor (12)
Is the light detection probe unit (1
3) is installed at a predetermined position around the bottom of the container body (1) so as to detect that the remaining amount of the high-purity chemical in the container body (1) has reached a predetermined amount. . Also,
The optical liquid level sensor (12) is connected to a light emitting / receiving device (14) and a detection circuit (15), and detects and detects the remaining amount of the high-purity chemical by a signal output from the detection circuit (15). Supply of high-purity chemicals when
It is configured to be able to perform various controls such as stopping the operation of a device using a high-purity chemical.

In the embodiment shown in FIG. 1, an example is shown in which one optical liquid level sensor (12) is installed.
Two or more optical liquid level sensors can be installed. In this case, a step is provided so that another light detection probe is located above the light detection probe that detects the remaining amount of the predetermined high-purity chemical, and the optical liquid level sensor is installed, so that the lower light is detected. Before the high-purity chemical at the detection probe part detection position reaches a predetermined remaining amount, a high-purity chemical is supplied by a high-purity chemical supply device as a warning that is issued at the light detection probe part detection position provided above it. Control such as notifying an operator in advance of a notice of supply stoppage of the fuel cell. In such an embodiment, it is necessary to stop the operation of the apparatus for supplying the high-purity medicine from the high-purity medicine supply apparatus of the present invention before the supply of the high-purity medicine from the high-purity medicine supply apparatus is stopped. This is convenient in some cases.

Next, an example of use of the high-purity chemical supply apparatus shown in FIGS. 1 and 4 will be described. First, a container main body having a shape as shown in FIG. 1 (inner diameter 24 cm, inner height 50 cm)
(1) and the lid (2) were washed with isopropylene alcohol (IPA) for electronic industry and ultrapure water in a class 1000 clean room, and then dried sufficiently in a clean oven (class 100). Next, the container body (1) and the lid (2) were joined, and an airtight test was performed. In addition, the light detection probe unit (1) of the optical liquid level sensor (12)
The optical liquid level sensor was installed so that the tip of 3) was at a position 5 mm from the bottom of the container body (1). Also, the optical liquid level sensor used here is F-Key manufactured by Keyence Corporation.
U-93. Next, 500 g of tetraethylorthosilicate (TEOS) as a high-purity chemical is filled into the container body (1) through the high-purity chemical injection port (3), and then TEOS is supplied through the high-purity chemical supply port (5). Extraction is started, and when the detection circuit (15) emits a signal indicating a change in the difference between the intensity of the emitted light and the incident light, the extraction of the TEOS is stopped, the lid (2) is removed, and the container body ( The TEOS remaining amount in 1) was measured. In addition, the number of particles of 0.2 μm or more in TEOS and TEOS residual liquid immediately after the start of extraction was measured. The results obtained by repeating this operation four times are shown below.

[0025]

Table 1 Table 1 Number of particles immediately after filling Number of particles in residual liquid Remaining liquid amount (particles / ml) (particles / ml) (g) First time 15.1 16.8 498 Second time 13.2 14.8 498 Third time 10.4 14.2 497 Fourth time 10.5 12.7 497

Next, using the apparatus shown in FIG. 4, cleaning and drying were performed in the same manner as described above, and TEOS was filled. A float (8) coated with a fluororesin was used. Table 2 shows the obtained results.

Table 2 Number of particles immediately after filling Number of particles in residual liquid (particles / ml) (particles / ml) First 720 1128 Second 630 922 Third 565 874 Fourth 639 1067

As is clear from the above test results, the high-purity chemical supply apparatus of the present invention has a significantly smaller number of particles immediately after filling and the number of particles in the residual liquid as compared with the conventional apparatus. It can be seen that the difference in the number of remaining liquid particles is small.

[0029]

According to the apparatus and method for supplying a high-purity chemical of the present invention, it is possible to monitor the remaining amount of the high-purity chemical in the container body.
Since the optical liquid level sensor is used, there is no generation of new particles in the container main body, and therefore, it is possible to supply the high-purity chemical while maintaining the purity of the high-purity chemical.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a high-purity chemical supply device of the present invention.

FIG. 2 is a diagram showing a configuration of a light detection probe section of an optical liquid level sensor used in the present invention.

FIG. 3 is a diagram showing another configuration of the light detection probe unit of the optical liquid level sensor used in the present invention.

FIG. 4 is a diagram showing a conventional high-purity chemical supply apparatus.

[Description of Signs] 1 Container main body 2 Lid 3 High-purity chemical injection port 4 Injection valve 5 High-purity chemical supply port 6 Supply valve 7 Shaft 8 Float 9 Detector 10 High-purity chemical 11 Bolt and nut 12 Optical Liquid level sensor 13 Photodetector probe section 14 Emitter / receiver 15 Detection circuit 16 Optical fiber for light emission 17 Optical fiber for light reception 18 Right angle prism 19 Protection tube 20 Conical prism

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[Procedure amendment]

[Submission date] October 15, 1999 (1999.10.
15)

[Procedure amendment 1]

[Document name to be amended] Drawing

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[Correction method] Change

[Correction contents]

FIG. 2

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

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Claims (5)

[Claims] 1. A container body made of stainless steel whose inner surface is electrolytically polished, and a lid that can be joined to the container body, wherein the container body and / or the lid are formed of the container body. A high-purity chemical inlet for injecting the high-purity chemical into the container, a high-purity chemical supply port for taking out the high-purity chemical from the container body, and at least one optical liquid level sensor. Supply equipment for high purity chemicals. 2. An optical liquid level sensor, comprising: a light projecting optical fiber and a light receiving optical fiber juxtaposed, wherein a plurality of optical liquid level sensors are provided for causing light emitted from the light projecting optical fiber to enter the light receiving optical fiber in front of the distal ends of the two optical fibers. The high-purity chemical supply device according to claim 1, wherein a light detection probe provided with a prism portion having an internal reflection surface is used. 3. The high-purity chemical supply device according to claim 2, wherein the tip ends of the light projecting optical fiber and the light receiving fiber in the light detection probe are widened forward. 4. The high-purity chemical supply device according to claim 1, wherein the internal electrolytic polishing stainless steel container is provided with a lid having a wide opening to the extent that the interior can be washed. 5. A step of injecting a high-purity medicine into the high-purity medicine supply apparatus from a high-purity medicine injection port of the high-purity medicine supply apparatus according to any one of claims 1 to 4; Supplying a high-purity chemical from a high-purity chemical supply port of the apparatus; detecting the remaining amount of the high-purity chemical in the high-purity chemical supply apparatus by at least one optical liquid level sensor;
And stopping the supply of the high-purity chemical based on the detected remaining amount information of the high-purity chemical.