JPH04147609A - Air cleaner device - Google Patents

Abstract

PURPOSE:To realize a clean air flow at a plurality of locations with a reduced amount of air intake by setting the amount of air through fan means in first and second air cleaners such that part of clean air sent from an upstream side first air cleaner is returned to the upstream side. CONSTITUTION:First and second air cleaners 30, 40 are provided upstream and downstream of a clean air flow passage so that clean air blown out from the first air cleaner 30 as a side flow 50 is incorporated in the second air cleaner 40 and is changed to a down flow 52 via the second air cleaner 40. Thereupon, part of the clean air blown out from the first air cleaner 30 is returned to the upstream side of the first air cleaner 30 along a return flow passage 54 without being directed to the second air cleaner 40.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) TECHNICAL FIELD The present invention relates to an air purifying device.

(Prior Art) For example, in recent semiconductor manufacturing equipment, as the density of elements increases, more precise processing is required. In order to ensure the yield of dense processing, there is an increasing demand to further reduce the adhesion of impurities to semiconductor wafers before and after processing.

Semiconductor wafers are processed in a clean atmosphere, and the transport and standby atmosphere for semiconductor wafers is also made to be a clean air atmosphere.In particular, the transport and standby positions are lowered depending on how the semiconductor wafer is held. Achieves clean air ventilation such as flow and side flow.

This type of device is disclosed in Japanese Patent Application Laid-Open No. 61-111524. Japanese Unexamined Patent Publication No. 62-146265, U.S. Pat.
Japanese Patent Publication No. 62-36817. This is disclosed in Japanese Utility Model Application Publication No. 64-26833.

These publications also state that the air blown by a motor fan, etc. is passed through a filter to become clean air.
A configuration has been disclosed in which this flow is applied to the wafer.

(Problems to be Solved by the Invention) By the way, each of the above-mentioned publications discloses a flow in a partial area, but does not disclose a configuration in which flow flows in a plurality of locations in a certain wide area. In such a case, it is sufficient to install multiple air purifiers, each with one unit of blower and filter, but if each of the multiple air purifiers is configured to take in air from the outside air, impurities contained in the outside air may be removed. is taken into each unit, and dirt on the filters of each unit becomes a problem.

Therefore, an object of the present invention is to achieve clean airflow at multiple locations with a small amount of air intake without having to independently intake air from the outside for each air purifier. To provide an air purifying device which can realize the above and can optimally flow air at each location with the minimum amount of air taken in even if the air flow areas are different between the two locations.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a first air purifier and a second air purifier each having at least a blowing means for blowing air and a filter. , downstream, and the first upstream
The first air cleaner is configured to return part of the clean air blown from the first air cleaner to the upstream side of the first air cleaner. The present invention is characterized in that the air volume by the air blowing means in the second air purifier is set.

In addition, in this air purifying device, the above-mentioned 1. The first air cleaner detects the pressure inside the second air cleaner at least while the air blowing means is in operation. A second detection means may also be provided.

(Function) Fresh air taken in from the outside on the upstream side by the blowing means of the first air purifier is purified by the filter of the first air purifier and then flows. The air is sucked in by the blowing means of the second air purifier and flowed to other locations via the filter. Here, a part of the air blown from the filter of the first air purifier is returned to the upstream side of the first air purifier without going to the second air purifier, and is returned to the air purifier of box 1 again. The air will be flowed through the first air purifier by the air blowing means of the container. Therefore, it is possible to realize a flow of clean air to two or more areas while reducing intake of fresh air that is relatively mixed with impurities.

1st. By detecting the pressure inside the second air purifier, for example by detecting the differential pressure with the atmosphere, it is possible to detect the dirty state of the filter.
Deterioration of filter function can be detected in advance.

(Example) Hereinafter, an example in which the present invention is applied to a vertical heat treatment apparatus will be specifically described with reference to the drawings.

In FIGS. 1 and 2, an automatic door 16 is provided on one side of a device housing 10 for carrying in a carrier 14 on which a plurality of, for example, 25 semiconductor wafers 12 are mounted. This wafer 12 is carried into and out of the carrier 1.
The wafer is inserted into a wafer storage groove provided in the wafer storage groove 4 and is stood vertically. The carriers 14 carried into the housing 10 in the {circle around (2)} direction are placed on an IQ boat 18 (for example, two carriers 14 can be placed thereon). Further, above it, a carrier stage 22 is provided that can store a plurality of carriers 14, for example, eight carriers 14 in two rows and four stages, and the carriers 14 can be moved up and down in the direction (3) by an elevator (not shown) to carry in and out. ing.

A vertical heat treatment furnace 24 for heat treating the wafer 12 is located in the housing 10.
A boat (not shown) made of a heat-resistant material such as quartz can be loaded and unloaded into the heat treatment furnace 24 . The wafer 12 is transferred between the boat and the carrier 14 by a transfer machine (not shown). Note that the carrier 14 carried into the IQ port 18 is turned over by 90 degrees. Therefore, the carrier 14 stored within the carrier stage 22 stores the wafer 12 in a horizontal state. Further, the transfer of the wafer 12 between the boat and the carrier 14 is also realized with the wafer 12 in a horizontal state.

Next, the flow of clean air inside the housing 10 will be explained.

On the top of the housing 10, there is an air intake port 26 for fresh air.
are arranged in a mesh pattern. A first air cleaner 30 is provided in the middle of the air flow path introduced into the housing 10 from the air intake port 26 and upstream of the carrier stage 22 . In addition, a second air purifier 40 is installed in the air flow path between the carrier stage 22 and the 6 port 18.
Or is provided.

The first air cleaner 30 has an air blowing area S1 capable of side-flowing clean air toward all the horizontal wafers 12 in the carriers 14 in two rows and four stages in the carrier stocker 22. On the other hand, the second air purifier 40 is ■Φ
It has an air blowing area S2 that allows clean air to flow down toward all the vertical wafers 12 in the two carriers 14 on the boat 18. Therefore, S]+S
The ratio is 2:4:1.

1st. As shown in FIG. 3, which schematically shows the configuration of the second air cleaner 30, 40, the second air cleaner 30, 40 has dampers 32, 42 each capable of adjusting the air intake flow rate, and a blower 34° having a fan, etc. for blowing air. 44, and filters 36 and 46 that collect dust and blow out clean air.

Here, each damper 32, 4 is adjusted so that the wind speed of the clean air is preferably 0.3 m/sec at a predetermined distance, for example, 10 cm from the blowing surface of each filter 36, 46.
The air blowing volume of 2 and the air volume of the blowers 34 and 44 are set.

1st. Since the second air cleaners 30 and 40 are provided upstream and downstream of the clean air flow path, the second air cleaners 40 and 40 are provided upstream and downstream of the clean air flow path.
The clean air blown out from the first air purifier 30 and made into a side flow 50 is taken in, and is made into a down flow 52 via the second air purifier 40. At this time, a part of the clean air blown out from the first air cleaner 30 does not go to the second air cleaner 40, but flows along the return flow path 54 to the upstream side of the first air cleaner 30. I'm trying to get back on track.

In this embodiment, the area ratio of each filter 36.46 is Sl:
52=4:1, each filter 36.
The air blowing amount Ql, , Q2 from 46 is Ql : Q2
#4: It is considered to be 1. Therefore, 3/4 of the total amount of air blown through the filter 36 is returned.

Therefore, the amount of fresh air taken in from the outside through the air intake port 26 is Q1/4, realizing a small amount of air intake. Such adjustments can be made by adjusting the settings of each damper 32, 42 and blower 34, 44 at the time of starting up the device, and can smoothly achieve the above-mentioned side flow and downflow without generating turbulence at a predetermined wind speed. That's what I do.

Furthermore, since the return flow path 54 is provided, the air blowing area of each air purifier 30, 40 is equal to Sl.

Even if it differs from S2, it can be set so that clean air flows out from each air cleaner 30, 40 at a desired wind speed.

Next, the effect will be explained.

In this device, a wafer 1 is housed in a carrier.
2 is realized at two locations within the device housing 10. One of these locations is the carrier stage 22, where the wafer 12 is held horizontally, thereby realizing side flow. The other location is the small IO port 8, where the wafer 12 is held in a vertical position, thereby realizing downflow. and,
In realizing this side flow and down flow, first. Second air cleaners 30 and 40 are provided upstream and downstream of the air flow path, and air is taken in from the outside only through the air intake port 26 on the upstream side of the first air cleaner 30.

In this way, the first. The air taken into the second air purifiers 30 and 40 is separated from each other without being introduced from the outside,
Since the air side-flowed by the first air cleaner 30 is circulated to the second air cleaner 40 side, it is possible to reduce the intake amount of outside air that contains a relatively large amount of impurities. Moreover, part of the clean air blown out from the first air cleaner 30 is returned. Therefore, the air taken into the first air purifier 30 is not only the fresh air from the air intake port 26, but in the case of this embodiment, 3/4 of the total intake air is linter air. . For this reason, simply the first. Second air purifier 3
The amount of fresh air taken in can be reduced more than when 0.40 is arranged in series.

Here, the order in which the carrier 14 is flowed into clean air is that when the carrier 14 is carried in through the auto door 16 and set in the IQ port 18, the down flow 52 is first performed;
Thereafter, when this carrier 14 is placed on the carrier stage 22, the side flow 50 will be realized.

Therefore, the carrier 14 in the carrier stage 22 existing on the upstream side of the second air cleaner 40 has already received the downflow 52 once and is in a relatively clean state. When the clean air that has been removed is reused for the downflow 52 via the filter 46, there is also the effect that the degree of contamination of the filter 46 can be relatively reduced.

Next, an example of such an air purifier management system will be described. Note that in this embodiment device, the above-mentioned first
．． In addition to the second air purifier 30.40, the third. It has a fourth air purifier 60.70. These are number 1. For example, it has the same configuration as the second air purifier 30° 40,
The side flows 56 and 58 shown in FIG. 2 are applied to the wafers 12 accommodated in the boat in a horizontal state before the boat is loaded and the wafers 12 accommodated in the boat in a horizontal state after unloading, respectively. It is located in a position where it can be realized. That is, the vertical heat treatment furnace 24
As shown in FIG. 1(B), there are two locations at the bottom of the device housing 10, which can be opened and closed, and which allow people to enter and exit during maintenance. Second door 80.8
2, and a third door 80.82 is provided inside this door 80.82. A fourth air purifier 60,70 is provided.

In this embodiment, the operating states of the first to fourth air purifiers 30, 40, 60.degree. 70 are monitored as shown in FIG. That is, each purifier 30
, 40, 60, and 70, for example, first to fourth differential pressure switches 90 for detecting the differential pressure with the atmosphere
．． 92, 94°96 are provided. A CPU 98 is provided to input the outputs of the switches 90 to 96, and the maintenance information or alarm information of each air purifier 30, 40, 60. That's what I do.

According to such a configuration, if each of the first to fourth purifiers 3
If there is less contamination in the filters of 0.40 and 60.70,
When the proafan is rotated at the set value, the pressure at each proafan section is always higher than atmospheric pressure. As the filter becomes more contaminated or clogged, the pressure increases. Therefore, each differential pressure switch 90 to 96 outputs a signal to the CPU 98 when the pressure rises above the set value, making it possible to centrally manage situations such as which air purifier is experiencing an abnormality. becomes.

Note that different pressure differences (e.g. 5m5H20, 4011H2
It is also possible to output more precise maintenance information by connecting two or more types of differential pressure switches that operate at 0, etc.) in parallel to each proafan section.

Note that the present invention is not limited to the above embodiments,
Various modifications are possible within the scope of the invention.

For example, this embodiment is not limited to being applied only to a vertical heat treatment apparatus of semiconductor manufacturing equipment, but can be applied to various types of apparatus that realize the flow of clean air at two or more locations. Furthermore, each air purifier only needs to have at least a filter and a blower, and the specific structures of the filter and the blower can be modified in various ways.

Furthermore, although the above embodiment describes an example in which two stages of air purifiers are installed on the upstream and downstream sides, it is also possible to install three or more stages, in which case clean air is supplied from the air purifier on the upstream side of each stage. All you have to do is return it. Further, although the above embodiment is an example in which the filter outlet area is different for each stage, it can be similarly applied to a filter having the same area, and in this case as well, there is an effect of reducing the amount of air taken in from the outside.

[Effects of the Invention] As explained above, according to the present invention, the first air cleaner and the second air cleaner are installed upstream of the air flow path.

A part of the clean air blown from the first air purifier located downstream and upstream is returned to the upstream side of the first air purifier, so the amount of air taken in from the outside is reduced. It is possible to achieve clean airflow at two or more locations while further reducing air flow.

[Brief explanation of the drawing]

FIGS. 1(A) and (B) are a front view and a plan view of a vertical heat treatment apparatus to which the present invention is applied; FIG. 2 is a schematic perspective view for explaining the flow of clean air in the embodiment apparatus. , Figure 3 shows the 1. FIG. 4 is a schematic explanatory diagram schematically showing the air flow by the second air purifier. FIG. 4 is a block diagram of a centralized management system for the operating states of the air purifiers at four locations. 12... Wafer 14... Carrier 18... IQ small port 2... Carrier stage 30.40.60.70... Air purifier 32.42...
・Damper 34.44...Blower 36.36...Filter 90-96...Differential pressure switch 98...CPU 100...Output section agent Patent attorney Inoue - (1 other person) Fig. 2 Figure 6

Claims (2)

[Claims] (1) A first air purifier and a second air purifier each having at least a blowing means for blowing air and a filter are arranged upstream and downstream of the air flow path, and the first air purifier on the upstream side the first air purifier so as to return a part of the clean air blown by the first
An air purifying device characterized in that the air volume of the air blowing means in the second air purifier is set. (2) In claim (1), the air purifier is provided with first and second pressure detection means for detecting the pressure within the first and second air purifiers at least while the air blowing means is in operation. Device.