JPH0447957Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an ultraviolet cleaning device.

Conventionally, ozone generated from ultraviolet lamps has been used to decompose and clean contaminants. For example, as a pretreatment when applying a photoresist to a silicon wafer, organic contaminants in the air that have adhered to the silicon wafer after main cleaning can be decomposed by additional cleaning immediately before application, or during sputtering deposition using an electron beam. It has become clear that the adhesion of a coated or deposited film can be significantly improved by additionally cleaning organic contaminants such as vacuum pump oil that have adhered to the substrate. It is also applied to many other objects to be cleaned, such as lenses and crystal oscillators, but in any case, if this ultraviolet cleaning device is used after the main cleaning step using the wet method, excellent cleaning effects can be obtained.

By the way, when an ultraviolet lamp, such as a low-pressure mercury lamp, is turned on, ultraviolet rays of the mercury resonance line with a wavelength of 254 nm are mainly emitted to the outside, and ultraviolet rays of 185 nm and a small amount of other wavelengths are also emitted. Then, ozone is generated by ultraviolet rays with a wavelength of 185 nm, and then this ozone is decomposed by ultraviolet rays with a wavelength of 254 nm, producing oxygen as a generating group.
It is known that oxygen from this generating group decomposes organic contaminants and scatters them in a gaseous state.

The cleaning mechanism using ultraviolet rays is as described above.
Ozone generated at this time is a harmful substance, and the amount leaked outside the device must also be within the range specified by environmental standards. In this ultraviolet cleaning device, the irradiation chamber is ventilated to some extent during operation in order to supply oxygen-containing gas and discharge decomposed gas from organic contaminants. However, since the purpose of ventilation was not primarily to remove ozone from the irradiation chamber after cleaning, the air volume was small and it took a long time for ozone to be completely removed. Therefore, if the door of the device is opened to take out the object to be cleaned after cleaning, the ozone inside may leak and exceed environmental standards, or the door must be opened after waiting for the ozone inside to be removed. There was a problem with the waiting time being longer if the door was closed.

Therefore, the purpose of the present invention is to provide an ultraviolet cleaning device that can open the door and safely take out the object to be cleaned within a predetermined short time after cleaning is completed. This is an ultraviolet cleaning device that generates ozone using light and decomposes and cleans organic contaminants that adhere to the surface of the object to be cleaned using the generated oxygen generated by the decomposition of this ozone. The irradiation chamber in which the cleaning body is supported is equipped with an exhaust device capable of ventilating the irradiation chamber with an air volume at least five times the volume of the irradiation chamber.

The present invention will be specifically described below based on embodiments shown in the drawings.

FIG. 1 shows a cross-sectional view of the apparatus, and a lamp body 2 is built into the apparatus box 1, forming a double structure to prevent generated ozone from leaking to the outside. The inside of the lamp body 2 is the irradiation chamber 3, and above it there are two U-shaped 350W high-output low-pressure mercury lamps as ultraviolet lamps 3, and behind them a mirror 5 is installed to direct the ultraviolet rays downward. is irradiated. A cooling water channel 6 is fixed to the upper surface of the ceiling of the lamp body 2 and is water-cooled. A cleaning object support stand 7 is disposed in the center of the irradiation chamber 3, and supports a cleaning object 8. The cleaning object 8 is taken in and out by opening and closing an opening/closing door 9. An intake hole 10 and an exhaust hole 11 are provided on the sides of the lamp body 2 for ventilation, and an exhaust device 20 is connected to the exhaust hole 11, in which ozone is decomposed and exhausted to the outside of the device box 1. It is becoming more and more common.

The exhaust device 20 has a removably built-in filter 30 as shown in FIG. The filter 30 can be easily removed when replacing it. A fan 24 is provided below the stepped portion 22, and the suction force of the fan 24 causes the air containing ozone in the irradiation chamber 3 to be exhausted through the exhaust hole 11 and the filter 30. This fan 24
The suction force is strong and the amount of air at least five times the volume of the irradiation chamber 3 can be discharged within a short period of one minute.

As shown in FIG. 3, the filter 30 has a cylindrical body 31 whose inner surface is coated with a fluororesin and in which honeycomb-shaped activated carbon 32 is held in multiple layers.
Of course, a catalyst such as manganese dioxide can also be used instead of the activated carbon 32, as long as it can adsorb or decompose ozone. A short cylindrical spacer 33 having a length of several mm is interposed between the activated carbons 32, 32, so that the activated carbons 32 are spaced apart from each other by several mm. Therefore, the air containing ozone that has passed through the honeycomb-shaped activated carbon 32 in a laminar flow becomes a turbulent flow in this gap and flows into the next activated carbon 32.
The reactivity with 2 is improved and ozone is efficiently adsorbed. Therefore, by arranging the honeycomb-shaped activated carbon 32 in five layers, 100 ppm of ozone can be adsorbed and decomposed to 0.1 ppm or less, meeting environmental standards. Note that the inlet portion is filled with glass fibers 34 to remove foreign matter.

In the cleaning apparatus configured as described above, when the object to be cleaned 8 is set on the support stand 7, the opening/closing door 9 is closed, and the ultraviolet lamp 4 is turned on, ultraviolet rays are irradiated and the object is cleaned. UV lamp 4
Even after the lights are turned off, the fan 24 continues to rotate, and its suction force guides the ozone-containing air into the exhaust system 20.The filter 30 adsorbs and decomposes the ozone to a level below environmental standards, causing it to flow outside the equipment box 1. is discharged. Then, during one minute after the lights are turned off, an air volume approximately five times the volume of the irradiation chamber 3 is exhausted and ventilated, so that the ozone in the irradiation chamber 3 falls below the environmental standard of 0.1 ppm. This can be understood from the fact that, for example, explosion-proof standards for electrical equipment stipulate that safety be ensured by ventilating the container five times as much as possible and then filling the container with inert gas. Therefore, even if the opening/closing door 9 is opened and the object to be cleaned 8 is taken out one minute after the lights are turned off, the environment will not be harmed by ozone leakage.

In this way, the ultraviolet cleaning device of the present invention can ventilate the irradiation chamber in which the object to be cleaned is supported at an air volume of at least five times the volume per minute, and has a built-in filter that adsorbs and decomposes ozone. As a result, the ozone in the irradiation chamber falls below environmental standards in a short time after the ultraviolet lamp is turned off. Therefore, according to the present invention, the door can be opened within a short time after cleaning is completed. It is possible to provide an ultraviolet cleaning device that can safely take out objects to be cleaned.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a sectional view of an exhaust device, and FIG. 3 is a sectional view of a filter. 1...Equipment box, 2...Lamp body, 3...Irradiation chamber, 4
...Ultraviolet lamp, 5...Mirror, 7...Support stand, 8...Object to be cleaned, 9...Opening/closing door, 10...Suction hole, 11...Exhaust hole, 20...Exhaust device, 24
... Juan, 30 ... Filter, 32 ... Activated carbon.

Claims (1)

[Claim for Utility Model Registration] Ultraviolet light is used to generate ozone with the light of an ultraviolet lamp, and to decompose and clean organic contaminants etc. that adhere to the surface of the object to be cleaned using the oxygen generated as a generating group generated by the decomposition of this ozone. A cleaning device capable of ventilating the irradiation chamber in which the object to be cleaned is supported at an air volume of at least five times the volume per minute, and equipped with an exhaust device equipped with a filter that adsorbs and decomposes ozone. Ultraviolet cleaning equipment.