JPS62160188A - Pure water tank - Google Patents

Abstract

PURPOSE:To perform the sterilization of stored water, by irradiating a pure water tank with ultraviolet rays from a sterilizing lamp having an ultraviolet lamp incorporated therein an an outer wall formed of ultraviolet ray pervious glass. CONSTITUTION:A water supply hole 4 is provided to the bottom surface of a main tank 2 and a drain hole 5 is provided to the bottom surface of a sub- tank 3. Pure water injected in the main tank 2 from the water supply port 4 fills the main tank 2 and subsequently overflows therefrom to flow in the sub-tank 5 and is drained from the drain port 5. A sterilizing lamp 6 is provided to the outer periphery of the main tank 2 and the ultraviolet lamp 10 incorporated in the sterilizing lamp 6 is allowed to light to irradiate the entire area in the main tank 2 with ultraviolet rays through an ultraviolet ray pervious glass 7. By this method, bacteria in the main tank 2 are killed and the propagation of bacteria in the main tank 2 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pure water tank for storing pure water used in semiconductor manufacturing.

Traditionally, when manufacturing semiconductors, a large number of pellets are obtained from a single semiconductor wafer through multiple manufacturing processes. However, if impurities are attached, the semiconductor will become a defective product.

For this reason, when manufacturing semiconductors, not only must the atmosphere at the work site be kept clean at all times, but also the surface of the semiconductor wafer must be cleaned with pure water to prevent impurities from adhering to the surface of the semiconductor wafer as much as possible. There is. by the way,
The pure water used for the above-mentioned cleaning is usually temporarily stored in a pure water tank, and is taken out from the pure water tank as needed and used for cleaning. Also, when pure water is poured into a pure water tank, the pure water is sterilized by ultraviolet irradiation, and bacteria and other microorganisms grow in the pure water tank, making it impossible to use the pure water as cleaning water. is prevented.

As mentioned above, when deionized water used for cleaning during semiconductor manufacturing is stored in a deionized water tank, the deionized water remains in the deionized water tank for a relatively long period of time. Water is stored in Therefore, even if the pure water is sterilized immediately before being injected into the pure water tank, if there are microorganisms such as bacteria on the inner wall of the pure water tank or in the air inside the pure water tank, these microorganisms will not be purified. There was a problem in that it would breed in the water tank, making it impossible to use it as pure water or cleaning water.

A sterilization cylinder with an ultraviolet lamp built into it and an outer wall made of ultraviolet-transparent glass is installed at any position inside the pure water tank, and the ultraviolet rays are irradiated from the ultraviolet lamp through the ultraviolet-transparent glass. The system is designed to irradiate the entire area inside the pure water tank with ultraviolet rays.

The pure water stored in the pure water tank is sterilized by irradiating the entire area inside the pure water tank with ultraviolet light using an ultraviolet lamp built into the vertical sterilizing cylinder.

Figure 1 shows a pure water tank (1) according to the present invention, and (2) in the figure shows the main tank of the pure water tank (1), (
3) is a sub-tank installed around the outer circumference of the main tank (2), and the water supply hole (4) is located on the bottom of the main tank (2).
), and drain holes (5) are provided on the bottom of each sub-tank (3). The pure water injected into the main tank (2) from the water supply hole (4) fills the main tank (2) and then overflows from the main tank (2), which is then transferred to the sub tank located on the outer periphery of the main tank (2). (
3) drain hole (5) provided in the sub-tank (3).
) is drained to the outside. (6) is the main tank (
2) is a sterilization cylinder installed on the outer periphery of the sterilization cylinder (6).
The main tank (2) is made up of an ultraviolet transmitting glass (7) forming a part of the side wall (2a), and a partition plate (8) arranged around the outer periphery of the ultraviolet transmitting glass (7). An ultraviolet lamp (IO) is installed in the sealed space (9) formed by the ultraviolet transmitting glass (7) and the partition plate (8).
The more irradiated ultraviolet rays pass through the ultraviolet transmitting glass (7) and irradiate the entire area inside the main tank (2). If it is inappropriate or impossible to irradiate the entire area inside the main tank (2) with - UV lamps (10), multiple UV lamps (10) can be incorporated into the sterilization tube (6). Alternatively, the ultraviolet lamp (10) is moved within the sterilization tube (6) by a motor or the like.

When pouring pure water into the pure water tank (1) configured as described above and storing the pure water in the pure water tank (1), the sterilizer tube (6
) If the ultraviolet lamp (10) built in the main tank (2) is turned on and ultraviolet rays are irradiated to the entire area inside the main tank (2) through the ultraviolet transmitting glass (7), the inner wall of the main tank (2) or the main tank (2) Even if microorganisms exist in the interior space, these microorganisms will be killed by the ultraviolet rays irradiated into the main tank (2), and the microorganisms will not proliferate within the main tank (2).

In addition, the sterilization cylinder (6) installed in the main tank (2) is not only installed on the outer periphery of the main tank (2) as shown in Fig. (
7) into the main tank (2).
), and the entire area inside the main tank (2) may be irradiated with ultraviolet rays by an ultraviolet lamp (10) installed in the sealed space (9) of this sterilization cylinder (2).

As mentioned above, in the pure water tank according to the present invention, water is stored in the pure water tank by irradiating the entire area inside the pure water tank with ultraviolet rays using an ultraviolet lamp built into the sterilizing cylinder. Since we have sterilized pure water, even if there are microorganisms on the inner wall of the pure water tank or in the air inside the pure water tank, these microorganisms will be killed by the action of ultraviolet rays, so it will not be possible for the microorganisms to enter the pure water tank. This prevents deionized water from growing and making the pure water unusable as cleaning water. In addition, if the pure water stored in the pure water tank is irradiated with ultraviolet rays for a long time, the particles contained in the pure water will be decomposed by the action of ultraviolet rays. It is also possible to prevent harmful effects on products during cleaning operations.Furthermore, since the pure water tank according to the present invention has an ultraviolet lamp built into the tank, there is no need to worry about ultraviolet rays leaking outside the pure water tank and having an adverse effect on the human body.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a pure water tank according to the present invention, and FIG. 2 is a sectional view showing an embodiment of a pond of the pure water tank. (1) - Pure water tank, (2) - Main tank,
3) - Sub-tank, (6) - Sterilizer tube, (7
)--UV-transparent glass, (10)-UV lamp. Patent applicant: Kansai NEC Corporation 1st generation
Rihito V Rugo
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Claims (1)

[Claims] (1) A pure water tank characterized in that a sterilizing cylinder with an ultraviolet lamp built therein and an outer wall made of ultraviolet-transparent glass is installed at any position within the pure water tank.