JPS597836A - Vertical laminar flow type dust-free chamber - Google Patents

Abstract

PURPOSE:To simplify the structure of the title chamber by a method wherein in the case of the vertical laminar flow type dustless chamber for manufacturing LSI devices and the like, operation zone filters and a passage zone filter having a surface area of filtering smaller than that of the former filter are housed in the same box and the open air and feedback air is introduced into the box. CONSTITUTION:The high performance filter 14 for use in the passage zone and the high performance operation zone filters 16 and 16' are provided in the same plane within the same box 19 and the surface area of filtering of the filter 14 is made smaller than that of each of the filters 16 and 16'. Further, the conditioned open air 4 and the feedback air 23 are taken into the box uniformly from right and left through inlet ports 21, 21' and sucking ports 22, 22', respectively, by using right and left blowers 15 and 15'. Then laminar flows of air in the same quantity are supplied from the operation zone filters 16 and 16', respectively, and another laminar flow of air is supplied from the passage zone filter 14. Thus, with the above structure, it is made possible to simplify the structure of the dust-free chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to simplifying the structure and reducing the cost of a vertical laminar flow type dust-free chamber.

In the manufacturing of ultra-small semiconductor devices such as LSI devices, the presence of floating dust of minute particle size in the manufacturing environment (==), which has not been a problem in the past, becomes a problem and has a large impact on its performance. As shown in the sectional view shown in the cross-sectional view, outside air or conditioned air (4), which is taken in through a blower (1) and a pre-filter (2) and a high-performance filter (3), is installed on the ceiling. A so-called laminar flow (airflow with uniform wind speed distribution below I m / S) is created through the high-performance filter (5), the suction port (6) provided on the floor, and the prefilter (7). A dust-free room with circulation inside the room (8) is used.

This system uses a high-performance filter (3) to make the intake air highly dust-free, and a high-performance filter (5) in the room (8).
), the LS
It is possible to create an extremely satisfactory clean air atmosphere that is suitable for manufacturing I-devices and the like. However, this method has the disadvantage of extremely high operating costs.

Therefore, recently, a vertical laminar flow system as shown in the sectional view shown in FIG. 2 has been used instead of the full vertical laminar flow system shown in FIG. In this method, for example, the section @ (8) is shaped like a long tunnel divided into left and right working areas (9) (9) and a central passage area a. 111, Prefilter Oz, 'Blower (
13): A filter chamber A equipped with a high-performance filter 0 (a) is provided, and the conditioned air (4) made dust-free is sent from the entire surface of the ceiling to the passage area aO+ in a laminar flow state. In addition, a filter chamber 13.B' with the same performance is provided in the upper part of the left and right working areas (91c+j), and the passage area (13.
0), and removes dust brought into the passageway by people entering and exiting, etc., while blowing the workbench (17) from the entire ceiling of the work area at the same wind speed as before.
(+7) J: is sent as a laminar flow and circulated. Note that (18) (ts) is the upper partition plate.

By the way, in this method, the air in the passage area 00) is transferred to the working area (00).
9) +9) IJ9 + Since it is necessary to prevent two people from getting into the work area, the speed at which air is fed through the filter chamber A is selected to be lower than the wind speed in the work area, for example, on the order of %. Therefore, when the volume of the room is the same, the air volume is smaller than that of the laminar flow system shown in FIG. 1, which has the advantage of saving energy and reducing operating costs.

However, in this type, as mentioned above, the passage area filter (IJ) and the work area filter f161 (Ifi),
Since the blowing air speeds are varied to provide different processing airflow, the filters in the work area are more likely to be clogged with dust than those in the passage area. Therefore, the ratio of wind speeds between the working area and the passage area cannot always be kept constant, and it is necessary to adjust the amount of air sent to the passage area dzeta filter 04) using the damper 01). Furthermore, in this type of filter, it is necessary to manufacture and install filter chambers B and H for the working area in addition to the filter chamber for the passage area, resulting in high equipment costs. Furthermore, in this method, conditioned air and circulating air are supplied through separate systems, so the temperature and humidity conditions in the work area and passage area must be made the same, as in the dust-free room shown in Figure 1. There is a drawback that it cannot be done.

The present invention aims to provide a vertical laminar flow type dust-free chamber that eliminates the above-mentioned drawbacks, and will next be described in detail with reference to the drawings.

3 and 4 are cross-sectional views showing one embodiment of the present invention, which is characterized by the following points. That is, high-performance filter 0 (a) for the passage area and high-performance filter a for the work area.
6) At the same time, a filter chamber D is provided on the ceiling in which +6+ is provided on the same plane in the same box (19), and at the same time, the filtration area of the high-performance filter Q41 for the passage area is reduced from that of the high-performance filter for the work area. The amount of air to be processed is expressed as %, which is smaller than that of Q61 flB+.For example, as shown in FIG. 22) From (22), the conditioned air (4) and the return air (23) (23) can be taken in equally on the left and right sides, or the conditioned air (4) can be taken in by one blower 00 as shown in Figure 4. ) and the return air (23) from the floor suction port (6) (23) and the air tact (24) (24) into the filter chamber D from the center.

and high-performance filters (16) for left and right work areas (16)
The same amount of laminar air is sent out from the passage area filter 04), and the processed air amount is % of the filter (16) (16).
It is designed to send out laminar air at a wind speed of %.

In this way, as mentioned above, it is possible to realize a dust-free chamber that eliminates the drawbacks of the vertical laminar flow type shown in Figure 2 while reducing operating costs compared to the vertical laminar flow type shown in Figure 1. becomes. That is, in the conventional device shown in No. 2121, separate filter chambers A, 13. However, in the present invention, each filter for the work area and the passage area (+4
) (16+06) is formed and attached. Therefore, its production and collection (
, the cost required for one ticket can be kept low. Moreover, in the present invention, conditioned air and return air are taken in and mixed in the box housing each filter (141 (If) F1G+) and are added to each filter.
It is possible to maintain uniform temperature and humidity conditions in the work area and passage area. In addition, in the method shown in Fig. 2, the air volume sent to the passage area filter o4) is adjusted by the air volume adjustment damper (11) and the blower 03) as described in 1 above, and the speed of the air sent to the passage is adjusted. It is lower than that of the work area to prevent air from entering the work area from the passage area. For this reason, there is a possibility that the clogged states of the filters in the passage area and the work area will be different, and the balance of the wind speed ratio will change during operation. For this reason, it is necessary to adjust the air volume using Danha 01), which makes the operation that much more troublesome. On the other hand, in the present invention, the C-passage device (1
The filtration area of the pipe is made smaller than that of the working area to obtain the required wind speed ratio between the passage area and the working area. For example, the filtration area of the passage area filter 041 is
When closed, the ventilation resistance is doubled, and the pressure is the same on the upstream side of each filter 0(a)(16+([)), so the passing air velocity of the passage area filter 04) is %. In this case, since the amount of air passing through per unit area of the filter paper of each filter (141 (+6 + +16) is the same, the speed of clogging in each is the same. Therefore, the amount of air sent is adjusted as in the conventional method. The wind speed ratio can always be kept constant without requiring any equipment or operation, and the drawbacks of the conventional method are eliminated.

The filtration area of the passage area filter (14) can be adjusted, for example, by making the filter into a wave shape by sandwiching a spacer (not shown) as shown in the cross-sectional views shown in FIGS. 5(a), (b), and (C). If the filter paper (25) is folded and glued into the frame (26), the length of the working area filter in the filtration direction as shown in FIG. As shown in Fig. 5(b), while keeping the bending pitch p□ the same, 12 is smaller than 11.
Alternatively, the bending pitch width may be set to 1)2, which is larger than p□, as shown in FIG. 5(C).

Furthermore, in the above, we have explained the case where the room is divided into three parts, into the left and right work areas and the central passage area, but for example, as shown in the cross-sectional view in Figure 6, it is possible to divide the room into two parts, such as a work area and a passage area. Needless to say, this can also be applied when the method is divided into multiple areas.

As is clear from the following explanation, according to the present invention, not only is the operating cost and equipment cost low, but the temperature and humidity inside the room are the same in each area, and the wind speed ratio between the work area and the passage area is , without the need for adjustment equipment or its operation.
It has various advantages such as being able to be kept constant at all times]11
．． It can provide a partially laminar flow type dust-free chamber, and has extremely large practical effects.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional vertical laminar flow type dust-free chamber, Figure 2 is a cross-sectional view of another improved vertical laminar flow type dust-free chamber, Figures 3 and 4.
The figures are cross-sectional views showing one embodiment of the present invention, and FIGS.
)(C) is a sectional view showing a method of adjusting the filtration area of the filter,
FIG. 6 is a sectional view of another embodiment of the invention. (8)... Room, (9), (9)... Working area, θ0)... Passage area, (11)... Damper for wind force adjustment, (+21... Prefilter, (13)・
...Blower, 04...High performance filter for passage area,
A, , B, B...filter chamber, Q7
) 07)...Workbench, (ts) (t8)・
...Partition plate, (19) ...Box, D...
... Filter chamber, (20) (20) ... Air blower box, (21) (21) ... Conditioned air inlet, (22) (22') ... Return air inlet, (
4) Conditioned air, (23) (23) Return air, (24) (24) Duct, (2
5)... Filter paper, (26)... Frame. Patent 1 Nyodai Oshisoku Research Institute Co., Ltd. Figure 1! P52 Figure 4 Figure 3 Figure 4 Bulletin board Figure 5 (a) (b) ↑

Claims (1)

[Claims] A filter for the work area and a filter for the passage area with a smaller filtration area are housed in the same filter box (two filters are housed in the same filter box, outside air or conditioned air and return air are fed into the filter box, and these filters are used for the work). A vertical laminar flow type dust-free chamber characterized in that dust-free air is blown out from the upper part of the area and the passage area.