JPH08332465A - Washing method and washing device - Google Patents

Abstract

PURPOSE: To provide a washing method and washing device capable of preventing the recontamination of wash during washing. CONSTITUTION: The liquid flow of a washing liquid 2 circulating horizontally in a washing tank 1 is made into unidirectional laminar flow 2a and the wash is moved (2) from downstream toward upstream in this unidirectional laminar flow 2a. Ultrasonic waves are radiated from an ultrasonic vibrator transducer 3 toward the washing liquid 2 during washing. The washing tank 1 has flow regulating plates 4 and 6 for regulating the liquid flow of the washing liquid 2 circulating horizontally in washing tank 1 to the unidirectional laminar flow and a rotating body 12 for holding and moving the wash from downstream to upstream in the unidirectional laminar flow 2a. The contamination of the washing liquid by stains separated from the wash during the washing are fewer in the upstream washing liquid than in the downstream washing liquid and, therefore, the recontamination during the washing is prevented when the wash is moved from downstream to upstream.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for cleaning semiconductor wafers, aluminum plates serving as substrates for hard disks, optical parts, glass plates, parts to which oil components are adhered, and other suitable cleaning methods. And a cleaning device.

[0002]

2. Description of the Related Art Conventionally, various cleaning methods and cleaning apparatuses for cleaning the contamination of an object to be cleaned have been known. FIG. 2 shows an example of a conventionally proposed cleaning device (Japanese Patent Laid-Open No. 6-106101).
(See Japanese Patent Publication).

In FIG. 2, the cleaning device has a rectifying device 21 provided at the bottom of the cleaning tank 20 over the entire cross section, and a return tank 22 and an overflow tank 23 provided at the upper portion thereof.
The circulation passage 24 from 2 is connected to the bottom of the cleaning tank 20 by providing a pump 25 and a filter 26. Then, the liquid 27 containing the contaminated particles overflowing from the overflow tank 23 is discharged, and the remaining cleaning liquid is circulated in the circulation passage 24. As a result, in the cleaning tank 20, the upward flow of the cleaning liquid becomes a uniform laminar flow in the entire cross section in the rectifying device 21, and the circulation of the particles is blocked in the cleaning tank 20 to remove the particles. 28 is a cleaning liquid supply port.

Thus, the fine particles in the cleaning liquid circulating in the cleaning tank 20 can be efficiently removed. By the way, in the said washing | cleaning apparatus, when a to-be-cleaned object is put in the washing tank 20 and it wash | cleans, the to-be-washed object must be put from the upper part of the washing tank 20. On the other hand, since the cleaning device circulates the cleaning liquid as an upward flow, the cleaning liquid layer above the cleaning liquid is contaminated by dirt, which is slightly separated from the object to be cleaned, than the cleaning liquid layer below. Therefore, when the washed object is pulled up, the object to be cleaned leads to recontamination when passing over the cleaning liquid.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention is to provide a cleaning method and a cleaning apparatus capable of cleaning an object to be cleaned without recontaminating it.

[0006]

According to the cleaning method of the present invention, the liquid flow of the cleaning liquid horizontally circulated in the cleaning tank is a unidirectional laminar flow,
The object to be cleaned is moved from the downstream side to the upstream side in the unidirectional laminar flow, and ultrasonic waves are emitted toward the cleaning liquid. A cleaning device that realizes the above-described cleaning method includes a cleaning tank, a rectifying unit that makes a liquid flow of a cleaning liquid horizontally circulating in the cleaning tank a unidirectional laminar flow, and a unidirectional laminar flow from downstream to upstream. And moving means for moving the object to be cleaned, and ultrasonic wave emitting means for emitting ultrasonic waves toward the cleaning liquid. It may be slightly inclined from the upstream side to the downstream side of the cleaning liquid flow circulating in the cleaning tank.

[0007]

EXAMPLES The principle of the cleaning method of the present invention is that, when the cleaning liquid is circulated in the horizontal direction and the cleaning target is cleaned, the degree of contamination of the cleaning liquid due to the dirt separated from the cleaning target is that the upstream cleaning liquid is lower than the downstream cleaning liquid. It is based on the recognition that there are few. Therefore, cleaning is performed by moving the object to be cleaned from downstream to upstream of the cleaning solution that circulates horizontally in the cleaning tank, and pulling the cleaned object from the cleaning tank on the upstream side of the cleaning solution. Recontamination can be prevented.

FIG. 1 is a longitudinal sectional view (A in FIG. 1) and a plane view (B in FIG. 1) of a main part of an embodiment of the present invention based on the above principle.
Is shown. In FIGS. 1A and 1B, 1 is a cleaning tank made of stainless steel or the like. There is. It is preferable that the supply port 14 is provided upstream of the straightening plate 4 that constitutes the straightening means described later.

An arbitrary number of ultrasonic vibrators 3, 3 are fixed to the outside of the bottom of the cleaning tank 1, and ultrasonic waves radiated from the ultrasonic vibrators 3 are used to soak the object in the cleaning liquid 2. Ultrasonic cleaning of the cleaning product.

Reference numeral 4 denotes a straightening plate provided near one end of the cleaning tank 1. The straightening plate 4 is a stainless steel plate having a plurality of circular through holes 4a arranged in a matrix in the vertical and horizontal directions. And is fixed to the bottom plate 1a and both side plates 1b and 1c of the cleaning tank 1. Then, the rectifying plate 4 rectifies the cleaning liquid 2 that circulates horizontally in the cleaning tank 1 to form a unidirectional laminar flow 2a. The size of the through hole formed in the straightening plate 4 is appropriately determined according to the flow rate and flow rate of the cleaning liquid.

Reference numeral 5 denotes an overflow tank, which is the rectifying plate 4
The cleaning tank 1 is partitioned by a rectifying plate 6 having a similar shape to that of the through hole 6a, and the cleaning solution and the overflow flowing out from the through hole are provided downstream of the circulating cleaning solution 2. Received cleaning liquid 2a. In addition, 7 is a reserve tank provided in parallel outside the cleaning tank 1,
The cleaning liquid 2a flowing out to the overflow layer 5 is reserved. The reserve tank 7 is provided with a skimmer or the like (not shown) and is effective in removing contaminants and the like floating on the surface of the collected cleaning liquid 2c. The reserve tank 7 may be provided as needed depending on the cleaning process.

Reference numeral 8 is a cleaning liquid circulation passage connecting the overflow tank 5 and the reserve tank 7, and 9 is a cleaning liquid circulation passage connecting the reserve tank 7 and the cleaning tank 1. A circulation pump 10 and a filter 11 for removing fine particles from the contaminated cleaning liquid are provided.

In the cleaning device thus constructed,
When the cleaning liquid 2 that is newly supplied into the cleaning tank 1 from the supply port 14 is circulated by the circulation pump 10, the cleaning liquid 2 is rectified by the rectifying plate 4 and the rectifying plate 6, and the overflow tank from the upstream to the downstream. The unidirectional laminar flow 2a is uniformly directed toward the No. 5 side.

On the other hand, an object to be cleaned (not shown) moves in the direction of the arrow in the cleaning tank 1 while being held by a predetermined holding means.
It is immersed in the cleaning liquid 2 of the unidirectional laminar flow 2a. The object to be cleaned immersed in the cleaning liquid 2 of the unidirectional laminar flow 2a is directed from the downstream of the laminar flow 2a to the upstream of the laminar flow 2a, that is, toward the side of the current plate 4 as indicated by the arrow. To move. Then, the cleaned object is pulled up in the direction shown by the arrow to move the cleaned object to the next cleaning step.

Further, since ultrasonic waves are radiated from the ultrasonic oscillator 3 toward the cleaning liquid 2, ultrasonic cleaning is performed while the object to be cleaned moves from the downstream side to the upstream side of the laminar flow 2a. It is possible to ultrasonically clean the contaminants attached to the object to be cleaned.

In FIG. 1B, the object to be cleaned immersed in the cleaning liquid 2 is placed on a predetermined holding means (not shown), and the holding means is provided on both inner sides in the longitudinal direction of the cleaning tank 1. The cleaning liquid supported and circulated by the attached rotating bodies 12, 12 is moved from the downstream side to the upstream side. In this case, the rotating body 12 may be driven by the motor 13 and rotated.

The object to be cleaned holding means is moved by the rotating body 1 as described above.
Instead of 2, the holding means on which the object to be cleaned is placed may be hung to move the object to be cleaned from the downstream side to the upstream side of the cleaning liquid,
In this case, the washing liquid is not disturbed by the rotating body 12, and a laminar flow can be stably obtained.

In cleaning the object to be cleaned using the cleaning device, the cleaning liquid circulating in the cleaning tank 1 has an inclination of 1 to 3 degrees, preferably 1 to 2 degrees from the upstream to the downstream. You may carry it out.

Since the cleaning liquid 2 may decrease due to evaporation or the like while circulating through the cleaning tank 1 or the like, the cleaning liquid 2 is appropriately replenished from the cleaning liquid supply port 14 as needed.

[0020]

As described above, according to the cleaning method and the cleaning apparatus of the present invention, the object to be cleaned is immersed in the circulating one-way laminar cleaning solution and moved from the downstream side to the upstream side.
The object to be cleaned is not re-contaminated while moving in the cleaning liquid, so that the cleaning effect is increased, and further, re-contamination when the cleaned object is taken out from the cleaning tank can be prevented.

[Brief description of drawings]

FIG. 1 is an explanatory view of a main part of an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a conventional cleaning device.

[Explanation of symbols]

 1 Cleaning Tank 2 Cleaning Liquid 2a Unidirectional Laminar Flow of Cleaning Liquid 3 Ultrasonic Transducer 4, 6 Rectifier Plate 4a, 6a Through Holes Formed in Rectifier Plate

Claims (7)

[Claims] 1. A cleaning method, wherein a liquid flow of a cleaning liquid horizontally circulated in a cleaning tank is a unidirectional laminar flow, and an object to be cleaned is moved from the downstream to the upstream in the unidirectional laminar flow. . 2. The cleaning method according to claim 1, wherein ultrasonic waves are emitted toward the cleaning liquid. 3. The cleaning method according to claim 1 or 2, wherein contaminants in the circulating cleaning liquid are removed. 4. A cleaning tank, a rectifying means for making a liquid flow of a cleaning liquid horizontally circulating in the cleaning tank a unidirectional laminar flow, and an object to be cleaned in the unidirectional laminar flow from a downstream side to an upstream side. A cleaning device comprising moving means for moving. 5. The cleaning apparatus according to claim 4, further comprising ultrasonic wave emitting means for emitting ultrasonic waves toward the cleaning liquid. 6. The cleaning device according to claim 4 or 5,
A cleaning device comprising: a circulation means for circulating the cleaning liquid; and a filter for removing contaminants in the cleaning liquid, the circulation means. 7. The cleaning apparatus according to claim 4, 5 or 6, wherein the cleaning liquid flow circulating in the cleaning tank is inclined from upstream to downstream.