JP2003214674A - Fan filter unit installation structure and clean room ceiling structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely prevent the leakage of electromagnetic waves at the location where a fan filter unit is installed to the ceiling. <P>SOLUTION: In this structure, a fan filter unit 20 is installed to a lattice window 18 of a lattice ceiling 16 consisting of conductive materials. Shield packing 30 of which gasket and outer periphery are wrapped with metal foil outer film is interposed between the fan filter unit 20 and the frames of the lattice window 18, on which the fan filter unit is mounted, and is installed with airtight seal while an electromagnetic shield is created between the lattice ceiling 16 and a casing 44 of the fan filter unit 20. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fan filter unit installation structure and a clean room ceiling structure,
In particular, the present invention relates to a fan filter unit installation structure and a clean room ceiling structure having an excellent electromagnetic wave shielding function.

[0002]

2. Description of the Related Art Generally, in a clean room, in order to ensure the cleanliness of the interior, air removed by a filter is blown out from an air outlet installed on the ceiling and sucked in through a suction port provided on the floor or wall surface. An air circulation system is adopted that allows fresh air to be taken in from outside while appropriately circulating it. Usually, a fan filter unit (FFU) is installed on the ceiling of the clean room, and the air introduced into the space above the ceiling is filtered and dust is supplied into the clean room. The fan filter unit is a HEPA filter or ULPA.
(Ultra Low Penetration Air-filter: Dust removal rate 99.99
99%) It consists of a filter and a fan and a motor provided on the back side of the filter, and it is placed as a unit, especially in the lattice frame part of the ceiling.

A ceiling used in a clean room is composed of an aluminum frame arranged in a lattice shape and a ceiling panel installed by mounting an edge on the frame so as to close a lattice space formed by the aluminum frame. Has been done. The fan filter unit is installed in the same way instead of the ceiling panel and usually has a casing sized to fit the grid space (eg 1500 x 750 mm) and the casing of the casing forming the air outlet. The edge of the lower surface is placed on the ceiling frame. Since it is necessary to hermetically shut off the inside and outside of the clean room at the installation joint surface of the fan filter unit and to ventilate the space between the ceiling space and the interior of the clean room, an elastic material is used for the joint surface between the fan filter unit and the ceiling frame. The intervening gasket.

By the way, it is important that the entire building of a clean room has an electromagnetic shielding effect. By providing this electromagnetic shielding function, the electromagnetic waves coming from the outside are not taken into the inside, and the electromagnetic waves generated inside are not leaked to the outside. Therefore,
It is possible to prevent the adverse effect of the electromagnetic waves coming from the outside from affecting the precision processing in the clean room, and to avoid the adverse effect of the electromagnetic waves generated in the clean room to the external surrounding environment. Therefore, an electromagnetic wave shield material is used for the ceiling panel and wall panel of the clean room to form the anechoic chamber.

[0005]

However, in the above-mentioned conventional structure, the ceiling panel and the wall panel itself have a shielding function, as seen in, for example, Japanese Unexamined Patent Publication No. 10-102624, but at their joints. It is structured so that it cannot exert its shielding function. In particular, in the part where the fan filter unit is mounted, the sealing function is secured by using the gasket made of EPDM, but this is an electrical insulator and an electromagnetic wave passage is formed, so that the electromagnetic wave is blocked. There is a problem in that the electromagnetic wave leaks into and out of the clean room through the gasket, because it cannot be reliably performed on the ceiling of the clean room.

When forming a conventional anechoic chamber, it is also known to use an electromagnetic shield packing in which a conductive rubber contains a carbon filler. However, since the carbon filler is electrically floating, it is against electromagnetic waves. There is no shielding function, and electromagnetic waves are substantially transmitted, and the electromagnetic shielding effect cannot be obtained.

In the present invention, attention is paid to the above-mentioned conventional problems, and it is possible to surely prevent electromagnetic waves from leaking at the installation portion of the fan filter unit on the ceiling, and at the same time, the entire ceiling has an electromagnetic shield function. It is an object of the present invention to provide a fan filter unit installation structure and a clean room ceiling structure that can be accurately exhibited.

[0008]

In order to achieve the above object, a fan filter unit installation structure according to the present invention is a structure in which a fan filter unit is installed in a grid window of a grid ceiling made of a conductive material. A gasket and a shield packing in which the outer peripheral surface of the fan filter unit is mounted on the frame portion of the grid window on which the fan filter unit is mounted are covered with a conductive metal foil skin, and an electromagnetic field is provided between the grid ceiling and the fan filter unit casing. The feature is that the shield is installed while being hermetically sealed. In this case, the lattice ceiling may be formed of an aluminum material, and the conductive metal foil that is the outer skin of the shield packing may be formed of the same aluminum material as the lattice ceiling.

A clean room ceiling structure according to the present invention is a clean room ceiling structure in which a closing plate having a conductive material attached to a grid window of a grid ceiling made of a conductive material and a fan filter unit are installed. In the fan filter unit, an electromagnetic shield electrically connected to the lattice ceiling by interposing a gasket and a shield packing in which the outer peripheral surface of the fan filter unit is mounted on the frame with a conductive metal foil outer skin. It is characterized by having a shielding function over the entire ceiling surface by constructing.
In this case, the lattice ceiling is equipped with a semi-closed plate that opens and closes according to the pressure difference between the inside and the outside, and a mesh made of a conductive material is provided in the opening of this half-closed plate, and the mesh, the shield packing, and the closure. You may make it provide a shield function to the whole ceiling surface by comprising the electromagnetic shield electrically connected by the board and the lattice ceiling supporting these.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Specific embodiments of a fan filter unit installation structure and a clean room ceiling structure according to the present invention will be described below in detail with reference to the drawings. 1 to 5 show a fan filter unit installation structure and a clean room ceiling structure according to an embodiment. First, FIG. 5 shows a panel structure constituting a clean room. The clean room 10 forms a grating floor panel 12 made of aluminum die cast, and this grating floor 1
The side wall panel 14 is built in 2 and the ceiling part is formed by the aluminum grid ceiling 16. As shown in FIG. 4 (1), a large number of rectangular lattice windows 18 are formed on the aluminum lattice ceiling 16, and a fan filter unit 20 and a closed ceiling panel 22, the details of which will be described later, will be described.
Alternatively, a semi-closed ceiling panel 24 is attached to form a ceiling surface that shields the inside and outside of the room. The fan filter unit 20, the closed ceiling panel 22 or the semi-closed ceiling panel 24 attached to the lattice window 18 is
As shown in the plan view of FIG. 4 (2), the peripheral portions of the lattice windows 18 are placed and fixed on the stepped portions of the lattice window 18 formed by the aluminum frame 32 having an inverted T-shaped cross section. It has become.

Further, such a clean room 10 is
The grating floor panel 12, the side wall panel 14, and the aluminum grid ceiling 16 form a rigid structure, and are installed inside the space formed by the slab of the building and the building wall 26 (see FIG. 5). The air in the space above the ceiling is purified from the fan filter unit 20 provided on the aluminum grid ceiling 16 and blown out into the clean room 10, and the blown purified air is taken in from the grating floor panel 12 to the underfloor.
A return air space 28 for recirculating the above-ceiling space is provided with a clean room side wall panel 14 and a building side wall 26.
It is formed between the two, and fresh air is appropriately taken in from the outside by means not shown to ensure the cleanliness of the clean room 10.

Here, the above-mentioned clean room 10 is airtightly shielded so that dust and the like does not enter from the outside, and the air taken into the inside is introduced only through the fan filter unit 20. It is necessary to avoid being affected by electromagnetic waves so that internal measuring equipment and processing equipment are not affected. In addition, it is necessary to block electromagnetic waves generated internally from processing machines so that they do not leak to the outside and affect the surrounding environment. For this reason, the grating floor panel 12, the side wall panel 14, the ceiling, and the like that form the clean room 10 are configured as an electromagnetic shield mechanism.

In particular, in this embodiment, the clean room 1
A system ceiling structure is adopted in the 0 ceiling portion, and the aluminum grid ceiling 16 is formed using an aluminum material which is a conductive material. When the fan filter unit 20 is installed in the lattice window 18 formed thereby, the gasket and the outer peripheral surface of the fan filter unit 20 and the frame portion of the lattice window 18 for mounting and supporting the fan filter unit 20 are covered with an outer cover of a conductive metal foil. With the shield packing 30 attached, a conductive circuit is formed between the aluminum grid ceiling 16 and the casing of the fan filter unit 20 while airtightly sealed and installed.

This concrete structure is shown in FIG. As shown in FIG. 5, the aluminum grid ceiling 16 has a substantially inverted T-shaped cross section.
It is an array of letter-shaped aluminum frames 32 arranged in a grid.
The intersections are supported via suspension rods 34 suspended from a ceiling slab (not shown). The fan filter unit 20 mounted on the lattice window 18 is composed of a filter (ULPA) 36 portion directly facing the clean room 10 and a fan unit 38 portion provided on the back side (back side of the ceiling) of the filter 36. The filter 36 is composed of a filter body 40 and a filter frame 42 made of an aluminum material provided on the outer periphery of the filter body 40. Further, the fan unit 38 has an aluminum casing 44 which covers a space behind the filter and has a space, and a punching portion 46 is provided on a top plate portion thereof to serve as an air inlet. Then, inside the aluminum casing 44, a fan 48 facing the punching portion 46 and a motor 50 as a driving source thereof are built in, and air is sucked from the space above the ceiling to remove dust through the filter 36. Air is blown into the clean room 10.

In such a fan filter unit 20, the filter frame 42 is mounted on the inverted T-shaped aluminum frame 32, and the shield packing 30 as shown in FIG. I have to. The shield packing 30 is made of elastic EPDM gasket 5
2. The outer peripheral surface of the aluminum foil 54 is wrapped with the outer skin of the aluminum foil 54. Such a shield packing 30 is shown in FIG.
As shown in FIG. 4, the filter frame 42 of the fan filter unit 20 and the aluminum casing 44 are also joined to each other. As a result, in the portion of the lattice window 18 where the fan filter unit 20 is mounted, the aluminum frame 32 and the filter frame 42 that form the lattice window 18, and the filter frame 42 and the aluminum casing 44 form an electric circuit. As a result, in the mounting portion of the fan filter unit 20, there is no electrically insulated portion, and the aluminum materials that are conductive materials are electrically connected to each other, and electromagnetic waves leak inside and outside through this unit mounting portion. There is nothing to do.

FIG. 3 shows a configuration in which a closed ceiling panel 22 and a semi-closed ceiling panel 24 are mounted on the aluminum grid ceiling 16 together with the fan filter unit 20, and electrical connection is achieved with these. The installation configuration of the fan filter unit 20 is the same as in the case of FIG. In the illustrated example, the grid window 1 located between the two fan filter units 20.
The semi-closed ceiling panel 24 is mounted on the eight portions, and the closed ceiling panels 22 are mounted on both end portions.

The semi-closed ceiling panel 24 has a structure in which ventilation is opened and closed depending on the pressure difference between the inside and outside of the space partitioned by it. In the embodiment, the room pressure of the clean room 10 is higher than the space above the ceiling by a predetermined amount or more. When it becomes, ventilation is opened and the internal air is returned to the space above the ceiling. Therefore, an opening window is formed in the semi-closed ceiling panel 24, so that an electromagnetic wave passage is formed. In order to prevent this, the semi-closed ceiling panel 24 is provided with a mesh 56 made of an aluminum material which is a conductive material. The mesh size of the mesh 56 is set according to the wavelength of the electromagnetic wave to be shielded. For example, when considering electromagnetic wave shielding centered on 100 MHz, target 300 times the wavelength of 300 MHz to shield. I am going to decide. Since the wavelength of 300 MHz is 1 m, the maximum mesh size interval is 1 m. Considering one cycle of a wave, it is half wavelength, 50
This can be dealt with by setting the mesh size to be cm or less. And such a semi-closed ceiling panel 24
Is also mounted on the aluminum frame 32 of the aluminum grid ceiling 16, but the shield packing 30 as shown in FIG. 2 is interposed at this joint portion as in the case of the fan filter unit 20. Such a shield packing 30 is similarly attached to the panel mounting surface of the completely closed ceiling panel 22. As a result, like the fan filter unit 20, the aluminum frame 3 that forms the lattice window 18 in both the semi-closed ceiling panel 24 and the closed ceiling panel 22.
An electrical conduction circuit will be formed between the two.

According to such an embodiment, an electrically insulating portion is provided between the fan filter unit 20 mounted on the aluminum grid ceiling 16, the closed ceiling panel 22, the semi-closed ceiling panel 24, and the aluminum frame 32. Is eliminated and an electrically connected circuit is formed, so that electromagnetic waves can be reliably blocked. In particular, since the specific frequencies to be shielded in the clean room 10 are targeted and can be accurately shielded, it is possible to provide a clean room having an effective electromagnetic shield structure and its ceiling shield structure.

[0019]

As described above, the present invention has a structure in which a fan filter unit is installed on a lattice window of a lattice ceiling made of a conductive material, and a gasket is provided on the frame portion of the fan filter unit and the lattice window on which the fan filter unit is mounted. And a shield packing whose outer peripheral surface is wrapped with a skin of a conductive metal foil are interposed, and an electromagnetic shield is formed between the lattice ceiling and the casing of the fan filter unit to be hermetically sealed and installed. A clean room ceiling structure in which a closing plate having a conductive material attached to a lattice window of a lattice ceiling made of a material and a fan filter unit are installed, and the fan filter unit has a lattice window mounting portion on a frame. With a gasket and a shield packing in which the outer peripheral surface of the gasket is wrapped with an outer cover of conductive metal foil, the gasket and The electromagnetically shielded function is provided on the entire ceiling surface by constructing a circuit that is electrically connected, so be sure to prevent electromagnetic waves from leaking from the installation part of the fan filter unit on the ceiling. This also makes it possible for the entire ceiling to properly exhibit the electromagnetic shield function.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a fan filter unit installation structure according to an embodiment.

FIG. 2 is a partial cross-sectional perspective view of a shield packing.

FIG. 3 is a cross-sectional view of the clean room ceiling structure according to the embodiment.

4A and 4B are an explanatory view and a partially enlarged plan view of a schematic plan configuration of an aluminum grid ceiling.

FIG. 5 is an explanatory diagram of a clean room configuration.

[Explanation of symbols]

10 ... Clean room, 12 Grating floor panel, 14 Side wall panel, 16 Aluminum grid ceiling, 18 Lattice window, 20 Fan filter unit, 22 Ceiling ceiling Panels, 24 ……… Semi-closed ceiling panels, 26 ……… Architectural walls, 28 ……… Return air space, 30 ……… Shield packing, 32 ………
Aluminum frame, 34 ... Hanging rod, 36 ... Filter, 38 ... Fan unit, 40 ... Filter body, 42 ... Filter frame, 44 Aluminum casing, 46 ... Punching part , 48 ......... fan, 50
……… Motor, 52 ……… Gasket, 54 ……… Aluminum foil, 56 ……… Mesh.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tadahiro Omi             2-1-17 Yonegabukuro, Aoba-ku, Sendai City, Miyagi Prefecture             301 (72) Inventor Yasuyuki Shirai             33-3 Yagiyama Kasumicho, Taishiro-ku, Sendai City, Miyagi Prefecture             Chisun Mansion 803 Yagiyama Kasumicho (72) Inventor Hideo Hanaoka             1-14-1 Uchikanda, Chiyoda-ku, Tokyo             Stand Plant Construction Co., Ltd. (72) Inventor Kikuji Kobayashi             1-14-1 Uchikanda, Chiyoda-ku, Tokyo             Stand Plant Construction Co., Ltd. (72) Inventor Ken Honma             1-14-1 Uchikanda, Chiyoda-ku, Tokyo             Stand Plant Construction Co., Ltd. (72) Inventor Kunihiro Shibata             1-14-1 Uchikanda, Chiyoda-ku, Tokyo             Stand Plant Construction Co., Ltd. (72) Inventor Kazuo Saito             4-2-8 Kanda Surugadai, Chiyoda-ku, Tokyo               Takasago Thermal Engineering Co., Ltd. (72) Inventor Masamitsu Kudo             4-2-8 Kanda Surugadai, Chiyoda-ku, Tokyo               Takasago Thermal Engineering Co., Ltd. (72) Inventor Shinobu Tomikawa             4-2-8 Kanda Surugadai, Chiyoda-ku, Tokyo               Takasago Thermal Engineering Co., Ltd. F-term (reference) 2E001 DH01 FA14 FA26 FA41 GA22                       GA32 GA51 HB01 HB04 HF02                 3L058 BF05 BF06                 5E321 AA41 AA46 GG01 GG05

Claims (4)

[Claims] 1. A structure in which a fan filter unit is installed on a lattice window of a lattice ceiling made of a conductive material, wherein a gasket and an outer peripheral surface of the gasket are attached to a frame portion of the fan filter unit and the lattice window on which the fan filter unit is mounted. An installation structure of a fan filter unit, characterized in that an electromagnetic shield is formed between the lattice ceiling and a casing of the fan filter unit with a shield packing interposed between the lattice ceiling and the casing of the fan filter unit. 2. The fan filter unit according to claim 1, wherein the lattice ceiling is made of an aluminum material, and the conductive metal foil, which is an outer cover of the shield packing, is made of the same aluminum material as the lattice ceiling. Installation structure. 3. A clean room ceiling structure in which a closing plate having a conductive material attached to a grid window of a grid ceiling made of a conductive material and a fan filter unit are installed, and the fan filter unit has a grid window. A gasket and a shield packing in which the outer peripheral surface of the gasket is wrapped with a conductive metal foil skin is interposed between the parts mounted on the frame of the, and the entire ceiling surface is constructed by forming an electromagnetic shield electrically connected to the lattice ceiling. A clean room ceiling structure characterized by having a shield function. 4. A semi-closed plate that opens and closes by ventilation due to a pressure difference between inside and outside is mounted on the lattice ceiling, and a mesh made of a conductive material is provided in an opening of the half-closed plate, the mesh and the shield packing, The clean room according to claim 3, wherein a shielding function is provided to the entire ceiling surface by forming an electromagnetic shield electrically connected to the closing plate and a lattice ceiling supporting the closing plate. Ceiling structure.