JPS6170332A - Clean bench cleaning device - Google Patents

Abstract

PURPOSE:To prevent a turbulent flow and a circulating flow from generating and staying by making it possible to adjust the flow amounts of a vertical falling air current from the upper part of a work room and a horizontal air current along a work bench from the rear part by blowing off pure air whose purification degree is elevated. CONSTITUTION:A work room 3 is encircled by both side walls 3s, and a rear wall 3a, the front surface is opened to the outside. On the upper surface of the work room 3 is provided a blow-off port 9 with a louver, and a vertical falling air current is blown off. Furthermore, from a flow amount adjustable blow-off port 14 opened at the lower part of the rear wall is blown off a horizontal air. The blow-off amount of the air current can be changed by adjusting the opening degree of an HS grill. Further, filters 8 and 12 are provided on the inlet sides of blow off ports 9 and 14.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cleaning device that further improves the air cleanliness of a vertical air flow type clean bench.

[Conventional technology]

Generally, processing of semiconductor wafers requires work in an extremely clean environment, so a work device called a clean bench is used in a clean room, and vertical airflow is differentiated by the direction in which clean air is blown out. It is known that there are two types: a type and a horizontal airflow type.

By the way, as a conventional vertical airflow type working device, there is one shown in FIG. 3 published in Japanese Patent Application Laid-Open No. 53-73076, for example.

The clean pliers 21 has a working chamber 23, which is a cubic space surrounded by walls on three sides by opening the middle front of the housing 22.
A filter 24 is provided in the upper part of the working chamber 23 to clean the gas sent thereto. A rectifying plate 25 is installed in the vicinity of the gas outlet of the filter 24 so as to be able to move up and down and rotate by any means.
The size of the through hole 26 can be adjusted as appropriate by means of a movable plate 27 provided so as to be slidable.

[Problem that the invention seeks to solve]

However, in such conventional clean pliers, the position and angle of the rectifying plate can be adjusted appropriately to obtain the gas flow direction, the flow velocity, the position of the maximum flow velocity, etc. Even though it is possible to almost completely prevent the occurrence of eddy currents and circulation flows by adjusting the size of the holes by sliding the movable plate, the airflow that blows down vertically from above will naturally occur if it hits the workbench. It is necessary to change the direction forward, and therefore it is impossible to avoid the occurrence of eddy currents and circulating flows, especially at the ends of the corner, not to mention the corner where the lower part of the rear wall and the workbench meet. Yes, and if a workpiece such as a semiconductor is placed on the workbench,
Eddy currents and circulating currents also occur around them, but it is difficult to eliminate them.

Therefore, there is a problem in that as the usage time passes, dust accumulates at the eddy current generation site, contaminating the working chamber and deteriorating the working environment.

Furthermore, providing a movable rectifier plate or a slidable movable plate within the working chamber not only generates dust due to these operations, but also has the drawback of reducing the working space.

[Means for solving problems]

This invention was made in view of the above-mentioned problem, and does not require a rectifying plate or a movable plate, and has an air outlet that can adjust the flow rate added to the lower part of the rear wall of the work chamber, and These problems are solved by blowing clean air forward horizontally at a required ratio to the amount of air that would be blown vertically.

[For production]

Clean air is blown out horizontally from the lower part of the rear wall at an appropriate ratio to the main stream of clean air that is blown down vertically from above the work room, so that it can be used not only in the corners of the work room but also in the It is possible to completely prevent the occurrence of eddy currents and circulating flows around the product.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

First, I will explain the configuration.

This clean bench 1 has a housing 2 as shown in FIG.
A working chamber 3, which is open to the outside with an opening 3k at the front of the middle part thereof, is formed by being surrounded on all three sides by both side walls 3S, 3S and a rear wall 3a, and the bottom surface is a working table 3d.

Regarding the fan box 4, an air intake port (with a pre-filter) 5 opens horizontally in the middle of the lower part of the housing 2, and a blower 6 is installed inside the fan box 4 at a further recessed position. The air duct 7 is guided to the upper part of the housing 2 along the rear outer wall 2a of the housing 2.

In order to send the main vertical downdraft of clean air to the work room 3,
A HEPA filter 8 and an air outlet (with a louver) 9 are installed above and below a box 11 for a fluorescent lamp 10, which also serves as a duct, on the work chamber 3.

On the other hand, a duct 13 in which a HEPA filter 12 of 1/6 the size of the filter 8 is mounted is attached in contact with the back surface of the rear wall 3a, and a duct 13 is installed in contact with the back surface of the rear wall 3a, and extends across the entire width of the lower part of the rear wall 3a as shown in FIG. Air outlet 14 with a large number of vertical slits as shown
is open to blow out supplementary clean air horizontally forward along the workbench 3d. Note that an HS grill 15 is provided on the duct 13 side, which allows fine adjustment of the opening degree of the air outlet 014 by any means.

Note that 16 is a caster for moving the clean pliers 1.

Next, we will discuss the effect.

When the blower 6 is started, air in the clean room is taken in through the air intake port (with pre-filter) 5, filtered, enters the blower 6, passes through the blower duct 7, and advances to the upper part of the housing 2. Most of the air is then subjected to secondary filtration through the HEPA filter 8, and is blown out as a vertically descending airflow into the work chamber 3 through the air outlet (with loopal) 9 with increased cleanliness.

On the other hand, some of the air passes through the HEPA filter 12 and is similarly subjected to secondary filtration to improve the cleanliness and to
Since the horizontal airflow is blown out over the entire width of the surface of the workbench 3d at almost the same wind speed as the vertically descending airflow, the vertically descending airflow also smoothly changes its direction forward.
- It is assisted and discharged into the clean room through opening 3k.

Therefore, there are no places where residual current or circulation flow occurs, and when a workpiece such as a semiconductor wafer is placed on the workbench 3d, even if a vortex or the like may occur around it, the horizontal airflow will Because it is immediately blown away and disappears,
A high degree of cleanliness is maintained in the work chamber 3 without the accumulation of dust, allowing work to be carried out in an excellent environment.

〔Effect of the invention〕

As explained above, this invention provides a work chamber that opens in front of a clean bench with a vertical descending airflow flowing from the north and a horizontal airflow with a desired flow rate flowing along the workbench from the rear. The system is designed to blow out clean air with increased purity, and the flow rate of the horizontal airflow can be adjusted appropriately, making it possible to completely prevent the generation of eddy currents, circulation flows, or stagnation. effective.

In addition, since there is no means to prevent the generation of eddy currents or circulating flows in the work chamber, it can be used spaciously without interfering with the work space, improving work efficiency. Since it is installed outside the working room and the operating parts can be tightly closed, there is also the advantage that even if dust caused by the operation of the adjustment mechanism is generated, it will not enter the working room.

[Brief explanation of drawings]

Figure 1 is a diagram of a clean bench showing an embodiment of the present invention, Figure I is a front view, Figure [[ is a vertical sectional view, and Figure 2 is a partial sectional view showing a horizontal air outlet Enlarged perspective view, 3rd
The figure is a vertical sectional view of a conventional clean bench, and FIG. 4 is a perspective view of a cooling plate. 1...Clean bench 3...Working room 3S...Side Wall 3a...Back Wall 4... ...Fun box 8...) (EPA filter 9...
...Air outlet (with louver) 12...HEP
A filter 14...Air outlet 15.17...I (S grill Fig. 1 - Fig. 2

Claims (1)

[Claims] The working room is surrounded on three sides by both side walls and the rear wall, and the front side is open to the outside, and vertically descending airflow is allowed to flow through the louvered outlet installed on the top surface, and the flow rate can be adjusted through the opening at the bottom of the rear wall. 1. A clean bench cleaning device characterized in that a horizontal airflow is blown out from an air outlet at a desired flow rate with respect to the vertically descending airflow, using clean air whose cleanliness has been increased through filters.