JPH0334424A - Washing equipment - Google Patents

Abstract

PURPOSE:To prevent the charging attachment of floating particle, foreign matter, etc., and cleanly wash an object to be washed without requiring re-washing process, by generating ion with an ionizer, and eliminating electrostatic charge on the object to be washed with the ionized air. CONSTITUTION:Drying is performed as follows: by a blower 42, clean air is sent to a drying and charge eliminating part 48 via a HEPA filter 2, the object 5 to be washed is exposed to the clean air for a specified time (about 5 minutes). On the other hand, charge elimination is executed by generating corona discharge by applying a high voltage between the electrodes 45a and 45b of an ionizer 43. Hence atom, molecule, etc., in the air are ionized and charged. The ionized air is blown out against the object 5 to be washed, together with the clean air sent from the blower 42. When the charge of ion has the sign opposite to the charge on the object 5 to be washed, the electrostatic charge on the object 5 to be washed is completely eliminated as the result of mutual cancellation of the charge.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to various electronic components or photomask blanks,
The present invention relates to a cleaning device for cleaning objects that require high cleanliness, such as glass substrates for masks.

[Prior Art] Conventionally, as a cleaning device for items to be cleaned that require high cleanliness such as photomask blanks, a multi-tank cleaning device generally uses a low boiling point organic solvent such as trichlorethylene, trichloroethane, IPA, or methylene chloride. A type cleaning device is known. This is a method of cleaning using a combination of steam cleaning, ultrasonic cleaning, immersion cleaning, etc. For example, the object to be cleaned is immersed in a cleaning solution consisting of pure water, isopropyl alcohol (hereinafter referred to as IPA), etc. in an immersion cleaning tank. It is immersed and cleaned with an ultrasonic generator for a certain period of time, then left in steam such as IPA in a steam cleaning tank for a certain period of time, cleaned by the IPA liquid condensed on the surface, and then removed from the steam cleaning tank. There is a cleaning device for drying.

[Problems to be Solved by the Invention] Incidentally, when cleaning the objects to be cleaned as described above, the objects to be cleaned are placed in a storage case and transported, but due to static electricity generated due to sliding with the storage case, etc. The object to be cleaned is easily charged with electricity, and if static electricity is generated between the object to be cleaned and the storage case, the object to be cleaned will be destroyed due to electrostatic discharge (for example, if the object to be cleaned is a photomask blank, There were problems such as destruction of the mask pattern, etc. In particular, when using a storage case made of tetrafluoroethylene, which has excellent chemical resistance, it is not conductive, so if the object to be cleaned is not conductive, static electricity is likely to be generated and the object to be cleaned will be charged. easy. Further, if the object to be cleaned is electrically charged, floating particles such as dust, foreign matter, etc. are attracted to the object to be cleaned and are charged, and there is a risk that the object to be cleaned may be recontaminated. When this recontamination occurs, in the case of cleaning equipment that uses IPA steam cleaning and drying tanks, the object to be cleaned (photomask blank)
If suspended particles or foreign matter adhere to the surface of the object to be cleaned when it is taken out from the IPA steam/cleaning tank, the surface temperature of the object to be cleaned will be high and it will be baked in. Clean air must be injected with an air gun, etc. Even if an attempt is made to remove the attached suspended particles, foreign matter, etc., it is not easy to remove them, and re-cleaning with a solvent or the like is required, creating a new burden. Therefore, the present invention has been made in view of the above-mentioned conventional problems, and its purpose is to remove static electricity generated on objects to be cleaned and remove floating particles.
It is an object of the present invention to provide a cleaning device that can clean objects to be cleaned without requiring a re-cleaning step by preventing charged adhesion of foreign substances and the like.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a cleaning device for cleaning an object to be cleaned with a cleaning liquid, includes a static elimination processing section having an ionizer, generates ions by the ionizer, It is designed to remove static electricity charged on the object to be cleaned using ionized air.

[Function] In the present invention, when an ionizer generates ions with charges opposite to the excessive positive or negative charges on the surface of the charged object and supplies them to the surface of the object to be cleaned, these charges are neutralized. The ionized air removes static electricity from the object to be cleaned, and the ionized air removes airborne particles.

[Example] Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 is a sectional view showing an embodiment of the cleaning device according to the present invention, FIG. 2 is a view of the same device taken along the line 1--2 in FIG. 1, and FIG. 3 is a perspective view of a storage case. In these figures, the present embodiment is applied to a cleaning device that cleans objects to be cleaned by immersion cleaning and steam cleaning; The EPA filter 3 is formed by dividing the space below the HEPA filter 2 into left and right parts in the cleaning chamber 1, and includes a cleaning section 4A, a drying/static eliminating section ( Static elimination processing section) 4
B is a shutter that can be raised and lowered freely.

The cleaning section 4A includes a cleaning object mounting table 7 on which a storage case 6 for storing the cleaning object 5 is placed, and an immersion cleaning tank 8.
The IPA steam cleaning tanks 9 are arranged in parallel along the transport direction of the object to be cleaned 5, that is, along the arrow A direction, and a transport arm guide 10 is provided along the transport direction A.

The objects to be cleaned 5 are plate-shaped objects such as photomask blanks and glass substrates, and are stored in a storage case 6 as shown in FIG.
A plurality of sheets are stored at predetermined intervals in the thickness direction in a state substantially perpendicular to , and placed on the cleaning target 111188 table 7 together with the storage case 6 .

The storage case 6 is supported between a pair of opposing left and right side plates 15.16, four connecting rods 17 to 20 that connect the side plates 15.16 to each other, and a side plate L5.16, and each object 5 to be cleaned is Hold it at a predetermined interval in the thickness direction, and
For example, the four connecting rods 17 to 20 are provided with four holding/movement regulating members 2■ that regulate movement in the left and right direction.
A pair of front and rear connecting rods 19 and 20 disposed at the bottom function as support members that support the surfaces below each of the objects 5 to be cleaned. As the holding/movement regulating member 21,
For example, as shown in FIG. 3, a rod-shaped body shaped like a series of abacus beds is formed by forming a large number of V-shaped grooves 22 on the circumferential surface, or as shown in FIG. A plate body 24 is used in which m-tooth-shaped unevenness 23 is continuously formed.

The immersion cleaning tank 8 stores a cleaning liquid 25 such as pure water or IPA. The IPA steam cleaning tank 9 includes a heater 31 that heats the IPA cleaning liquid 26 stored in the lower part to turn it into steam 27, a condensing coil 28 that condenses the steam 27, and an object to be cleaned 5.
The elevator 29 is provided with an elevator 29 and a drive source 30 for raising and lowering the elevator.

The transport arm guide 0 is constituted by vertical and horizontal elongated holes, and extends in the transport direction A of the object to be cleaned 5,
a horizontal hole 10A having one end located above the washing object mounting table 7 and the other end extending to the drying/static eliminating section 4B; and a horizontal hole 10A having an upper end communicating with the washing object mounting table 7,
The first to fourth belts are provided corresponding to the immersion cleaning tank 8, the fPA steam cleaning tank 9, and the conveyor belt 32 of the drying and static eliminating section 4B.
A transport arm 33 that holds the storage case 6 is movably disposed on the guide 10.

As shown in FIGS. 2 and 3, the transport arm 33 is disposed horizontally so as to be orthogonal to the transport direction A, and its base end is connected and held to the moving part 35A of the cylinder 35. The cylinder 35 is movably disposed on a conveyance rail 36 extending in the conveyance direction, and raises and lowers the moving section 35A. A pair of holding plates 37 that are formed in an inverted T shape and hold the storage case 6 are provided at the free end of the transfer arm 33.
A and 37B are arranged facing each other. Each holding plate 37A
, 37B, that is, the inner surface of the horizontal support part 39A, is fitted with a bottle receiving member 38 having a 0-shaped groove 38A on the upper surface. The storage case 6 is lifted up by hooking the protrusions 40 protruding from 15 and 16.

In order to engage the protrusion 40 with the groove 38A when holding the storage case 6, the holding plates 37A and 37B are shifted and lowered relative to the storage case 6 in the conveying direction, and the bottle receiving member 38 is moved below the protrusion 40. position, and then the holding plate 37A,
37B toward the storage case 6 and attach each side plate 15.
16, the vertical portion 39B is positioned between the pair of protrusions 40, the bottle receiving member 38 is made to correspond to the protrusion 40, and the holding plates 37A, 37B are raised in this state.

Then, the protrusion 40 engages with the groove 38A of the bottle receiving member 38, and the storage case 6 can be held.

The drying and static eliminating section 4B includes the conveyor belt 32 and the HEPA
Air blower fi42 located above filter 2 and HEPA
An ionizer (air ionization device) 43 which is an air ionization device located below the filter 2, that is, downstream of the blower 42, is provided. The conveyor belt 32 picks up the storage case 6 conveyed by the conveyor arm 33 from the cleaning section 4A and conveys it in the conveyance direction A at a constant speed, while drying the object 5 to be cleaned and using the ionizer 4.
The static elimination operation according to step 3 is performed.

The ionizer 43 uses high-pressure corona discharge to ionize the air in the drying and static eliminating section 4B, and includes a pair of terminals 45a and 45b, and when a high voltage is applied between the electrodes 45C, Corona discharge occurs between the electrodes 45a, 45b and the air, and the air can be ionized. As such an ionizer 43 itself, a commercially available one is generally used.

Next, a description will be given of the cleaning and static neutralization operations of the object to be cleaned using the cleaning apparatus having the above configuration.

When the storage case 6 that stores the object 5 to be cleaned is placed on the object mounting table 7, the transport arm 33 moves to the transport arm guide 1.
0 along the first vertical hole 10B, move the pair of left and right holding plates 37A and 37B in the direction of extension of the side surfaces and at a height below the protrusion 40, and position them at both sides of the storage case 6. After that, remove the bottle receiving members 38 of the holding plates 37A and 37B.
is engaged with the protrusion 40 from below. And transport arm 3
3 is raised by the cylinder 35, the holding plate 37A
, 37B lifts the storage case 6. Transfer arm 33
is moved in the transport direction along the transport rail 36, and when it reaches the upper position of the immersion cleaning tank 8, it descends along the second vertical hole 10C to transfer the storage case 6 to the cleaning liquid 2 in the immersion cleaning tank 8.
5 for a certain period of time to clean the object 5 in the storage case 6. At this time, if the cleaning liquid is IAP, ultrasonic cleaning is performed using an ultrasonic generator, and if pure water is used as the cleaning liquid, high frequency cleaning is used in combination to achieve higher cleanliness.

When the immersion cleaning is completed, the transport arm 33 rises along the second vertical hole 10C, moves in the transport direction along the horizontal hole OA, and reaches above the IPA steam cleaning tank 9. 3 along the vertical hole 10D, and place the storage case 6 on the placing part 29a of the elevator 29. When the storage case 6 is placed on the elevator 29, the elevator 29 is lowered by the driving of the drive source 30, and the storage case 6 is left in the IPA steam cleaning tank 9 for a certain period of time. The storage case 6 is placed in the steam 27 inside the chamber and the steam cleaning process is performed.

That is, when the IPA vapor 27 touches the surface of the object to be cleaned 5 in the storage case 6, it condenses, adheres to the surface, flows down, and cleans the object to be cleaned 5. Thereafter, it is pulled up above the paper line 50 formed in the condensing coil 28 portion, thus completing the series of cleaning steps.

After the cleaning process is completed, the transport arm 33 moves in the transport direction along the horizontal hole 10A of the transport arm guide 10, moves the storage case 6 from the cleaning section 4A to the drying/neutralizing section 4B, and the transport belt 32 is hand over.

Here, the shutter 3 that partitions the cleaning section 4A and the drying and static eliminating section 4B is vertically movable, and normally both the sections 4A and 4B are movable up and down.
When the transport arm 33 passes, it is lowered by a drive motor (not shown) and stored in the shutter storage recess 49, thereby allowing the transport arm 33 to pass through.

The conveyor belt 32 conveys the storage case 6 received by the conveyor arm 33 in the conveyance direction A, and during this time, the object to be cleaned 5 is dried and static electricity is removed.

That is, drying is performed by sending clean air by the blower fi 142 through the HEPA filter 2 to the drying/static eliminating section 4B, and exposing the object 5 to be cleaned to the clean air for a certain period of time (about 5 minutes in this embodiment).

On the other hand, static elimination is performed by electrodes 45a and 45b of the ionizer 43.
Corona discharge 46 may be generated by applying a high voltage between them. Then, atoms, molecules, etc. in the air are ionized and charged by the corona discharge, and this ionized air is blown onto the object 5 to be cleaned together with the clean air sent by the blower 42. At this time, if the charge of the ions is of the opposite sign to the charge on the object to be cleaned 5, the static electricity charged on the object to be cleaned 5 can be completely removed by canceling the charges.

Thereafter, the storage case 6 is taken out from an outlet (not shown) provided in the drying/static neutralization unit 4B, and the process of cleaning the object to be cleaned 5 and eliminating static electricity is completed.

In addition, although the above-mentioned example was applied to a cleaning device that cleans the object 5 to be cleaned by immersion cleaning and steam cleaning, the present invention is not limited to this, and various modifications can be made. It is possible.

[Effects of the Invention] As described above, the cleaning device according to the present invention generates ions using an ionizer and applies these ions to the object to be cleaned, so that the object to be cleaned and the storage case are not electrically charged. Static electricity can be reliably removed, and since the object to be cleaned is not charged, it is possible to prevent electrostatic damage due to electrostatic discharge, and it is also possible to prevent re-contamination of the object to be cleaned, so it can be used to clean the object to be cleaned. It has great effects, such as being able to be cleaned.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the cleaning device according to the present invention, FIG. FIG. 2 is a plan view of a main part showing another embodiment of the holding/movement regulating member. l...Cleaning chamber, 2...HEPA filter, 4A...
・Cleaning section, 4B...Drying and static elimination section, 5...Object to be cleaned, 6...Storage case, 8...Immersion cleaning tank, 9...
IPA steam cleaning tank, 42...Blower, 43...Ionizer, 45a, 45b...Terminal, 45C...Electrode.

Claims (1)

[Claims] In a cleaning device that cleans an object to be cleaned with a cleaning liquid,
1. A cleaning device comprising: a static elimination processing section having an ionizer; the ionizer generates ions; and the ionized air removes static electricity from objects to be cleaned.