JPH11309425A - Washing tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow the water stream to easily form a laminar flow in a flow straightening type washing tank. SOLUTION: The washing tank 20 is provided with a tank main body 11 for string an article 2 to be washed inside and washing the article 2 to be washed with a fed washing liquid 1, a liquid feeding port 12 provided on the bottom of the tank main body 11, a flow straightening plate 13 provided on the lower part inside the tank main body 11 and on the upper side of the liquid feed port 12 to form plural flow straightening holes 13a, and a flow straightening upper cover 21 provided on an open face at the upper side of the tank main body 11 to enable to open and close it to form plural flow straightening holes 21a having taper surfaces made smaller in the opening diameter upward.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rectifying type cleaning tank for cleaning an object to be cleaned such as a wafer or a substrate placed in a tank body.

[0002]

2. Description of the Related Art FIG. 4 is a front sectional view showing an example of a conventional rectifying type cleaning tank. In FIG. 4, a liquid supply port 12 is provided at the bottom of the tank body 11 of the cleaning tank 10, and a current plate 13 is provided below the inside of the tank body 11 and above the liquid supply port 12. I have. The rectifying plate 13 has a number of rectifying holes 13a. Tank body 11
The cleaning object 2 is accommodated in the
The cleaning liquid 1 is supplied into the tank main body 11 from the tank 2, overflows from the upper opening surface of the tank main body 11, and the cleaning liquid 1 is received in the storage tank 14.

[0003]

However, in the above-described conventional cleaning tank 10, since the cleaning liquid 1 flowing out of the current plate 13 flows toward the side wall of the tank main body 11 (in the direction of the arrow in FIG. 4), the cleaning liquid is removed. There was a problem that the flow of 1 was difficult to become a laminar flow. Then, as shown in FIG. 4, a turbulent flow 1a occurs near the lower side wall in the tank body 11, and a uniform water flow (flow velocity) cannot be obtained at all points of the object 2 to be cleaned. There is a problem that particles remain in a part of the object 2. In particular, in the rectifying type cleaning tank 10, since the cleaning liquid 1 overflows from the opening side of the tank main body 11, there is a problem that a stagnation portion of the cleaning liquid 1 is generated and particles remain. Also, it is difficult to cleanly flow the cleaning liquid 1 toward the upper opening surface of the tank body 11, and the cleaning liquid 1 once touched by the air on the upper opening surface of the tank body 11 often returns to the inside of the tank body 11 again. . For this reason, DIW
However, there is a problem that it is difficult to control the specific resistance.

[0004] Therefore, an object to be solved by the present invention is to make a water flow easily laminar in a rectifying type washing tank.

[0005]

According to a first aspect of the present invention, there is provided a tank body for accommodating an object to be cleaned and cleaning the object with a supplied cleaning liquid. A liquid supply port provided at the bottom of the tank body, a flow straightening plate provided below the inside of the tank body and above the liquid supply port, and formed with a plurality of first flow straightening holes; A rectifying upper lid is provided on the upper opening surface of the main body so as to be openable and closable, and has a plurality of second rectifying holes having a tapered surface whose opening diameter is reduced upward. According to a second aspect of the present invention, in the cleaning tank according to the first aspect, an outer edge of each of the second rectifying holes is adjacent to a lower surface side of the rectifying upper lid.

[0006]

In the present invention, the cleaning liquid enters the tank body through the liquid supply port at the bottom of the tank body, and further passes through the first straightening hole of the straightening plate to wash the object to be cleaned, and the washing liquid is supplied to the first straightening hole of the straightening upper lid. 2 It flows out of the tank body from the rectification hole. Therefore, the cleaning liquid is
The cleaning liquid in the tank main body has a laminar flow because it flows uniformly upward from below without flowing toward the side wall of the tank main body. Further, since the second rectifying hole has a tapered surface whose opening diameter is reduced upward from the side where the cleaning liquid enters (lower surface side), the turbulence does not occur when the cleaning liquid hits the rectifying upper lid.

[0007]

An embodiment of the present invention will be described below with reference to the drawings. In the following embodiments, the same parts as those of the conventional example are denoted by the same reference numerals. FIG. 1 is a front sectional view showing an embodiment of the cleaning tank according to the present invention. The cleaning tank 20 is of a rectifying type, in which an object 2 to be cleaned, for example, a silicon wafer or a glass substrate of a liquid crystal display, is accommodated in the tank body 11 and is cleaned with the cleaning liquid 1 supplied into the tank body 11. is there. In addition, the to-be-cleaned object 2 is supported in the tank main body 11 by the receiving stand (not shown) installed in the bottom face.

The tank body 11 is made of quartz glass or PTFE having excellent chemical stability, mechanical strength, acid resistance and heat resistance.
(Polytetrafluoroethylene) and the like. A liquid supply port 12 for supplying the cleaning liquid 1 into the tank main body 11 is provided substantially at the center of the bottom of the tank main body 11.
Further, a rectifying plate 13 having a number of rectifying holes (first rectifying holes) 13a is attached below the inside of the tank body 11 and above the liquid supply port 12.

A rectifying upper lid 21 is provided on the upper opening surface of the tank body 11. In the present embodiment, the rectifying upper lid 21 is constituted by a pair of rectifying upper lids that come into contact at substantially the center of the opening surface of the tank main body 11. Upper lids 22 for preventing fumes from rising are provided on both upper ends of the cleaning tank 20 so as to be rotatable about support shafts 23, and a rectifying upper lid 21 is attached to the upper lids 22. Therefore, the rectifying upper lid 21 can be automatically opened and closed as the upper lid 22 rotates. The rectifying upper lid 21 may be simply detachably mounted on the opening surface of the tank body 11 without providing the rectifying upper lid 21 in this way. The rectifying upper lid 21 is formed from the same material (described above) as the tank main body 11. Also,
Although not shown, the opening / closing mechanism of the upper lid 22 is formed using an actuator, a cylinder, a screw feed mechanism, a gear mechanism, or the like.

The rectifying upper lid 21 has a number of rectifying holes (second rectifying holes) 21a. FIG. 2 (a) and (b)
FIG. 3 is a cross-sectional view showing the first and second embodiments of the rectifying hole 21a of the rectifying upper lid 21 in detail, and FIG. 3 is a plan view showing a state where the rectifying hole 21a of the rectifying upper lid 21 is viewed from the lower surface side. is there. The rectifying hole 21a is formed so as to have a tapered surface whose opening diameter is reduced upward. On the lower surface side (the side with the larger opening diameter) of the rectifying upper lid 21,
The rectification holes 21a are arranged so that the outer edges thereof are adjacent to each other. The rectifying hole 21a may be provided with a tapered surface over the entire range from the lower surface side to the upper surface side as shown in FIG. 2A. However, as shown in FIG. A tapered surface may be provided in the range, and a part of the upper surface may be formed in a straight shape.

In the cleaning tank 20 having the above structure, the object 2 to be cleaned is accommodated in the tank body 11 and the liquid supply port 1 of the tank body 11 is accommodated.
The cleaning liquid 1 is supplied from 2. The supplied cleaning liquid 1 flows upward through each of the flow straightening holes 13a of the flow straightening plate 13, and hits the cleaning target 2 to clean the cleaning target 2. Cleaning solution 1
When the water flows further upward, it flows out of each of the rectifying holes 21a of the rectifying upper lid 21 to the upper side of the rectifying upper lid 21 and is stored in the storage tank 14 provided on the upper outer peripheral portion of the tank body 11. In FIG. 1, the flow direction of the cleaning liquid 1 is indicated by an arrow.

When the cleaning liquid 1 flows out of the rectifying hole 13a of the rectifying plate 13, the cleaning liquid 1 flows upward as it is and flows therethrough.
Since the water flows out from the first rectification hole 21a, it does not flow toward the side wall of the tank body 11 as in the conventional example, but flows uniformly from below to above. Thereby, the tank body 11
The flow of the cleaning liquid 1 in the inside becomes a laminar flow. Furthermore, the rectification hole 21
Since a has a tapered surface whose opening diameter is reduced upward from the side (lower surface side) into which the cleaning liquid 1 enters, it is possible to prevent the cleaning liquid 1 from hitting the lower surface of the rectifying upper lid 21 and causing turbulent flow. Further, it is preferable to arrange the rectifying holes 21a such that the outer edges of the rectifying holes 21a are adjacent to each other on the lower surface side of the rectifying upper lid 21 as in this embodiment, because the contact between the cleaning liquid 1 and the rectifying upper lid 21 can be reliably prevented.

[0013]

According to the present invention, the cleaning liquid flows uniformly from below to above, so that the cleaning liquid in the tank main body can be made laminar. In addition, the second
The taper surface provided in the rectifying hole can prevent the cleaning liquid from hitting the rectifying upper lid and causing turbulence. Thereby, the efficiency of removing particles from the object to be cleaned can be increased, and the etching rate of the wafer can be made uniform. In addition, by determining the size of the rectifying hole of the rectifying upper lid according to the supply liquid amount, the pressure inside the tank main body can be kept high, so that the cleaning liquid once flowing out from the upper side of the tank main body is re-entered into the tank main body. Without returning, DIW specific resistance management can be easily performed.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing an embodiment of a cleaning tank according to the present invention.

FIGS. 2A and 2B are cross-sectional views illustrating a flow straightening hole of the flow straightening lid of FIG. 1 in detail, and FIGS. 2A and 2B illustrate first and second embodiments, respectively.

FIG. 3 is a plan view showing a state in which a rectifying hole of the rectifying lid of FIG. 1 is viewed from a lower surface side.

FIG. 4 is a front sectional view showing an example of a conventional rectifying type cleaning tank.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 cleaning liquid 2 object to be cleaned 11 tank body 13 rectifying plate 13a rectifying hole (first rectifying hole) 14 storage tank 20 cleaning tank 21 rectifying upper lid 21a rectifying hole (second rectifying hole) 22 upper lid

Claims (2)

[Claims] 1. A tank body for accommodating an object to be cleaned therein and for cleaning the object to be cleaned with a supplied cleaning liquid; a liquid supply port provided at a bottom portion of the tank body; A rectifying plate provided below the inside and above the liquid supply port and formed with a plurality of first rectifying holes, and provided on the upper opening surface of the tank main body so as to be openable and closable, and has an opening diameter upward. Second with reduced taper surface
A cleaning tank, comprising: a rectifying upper lid having a plurality of rectifying holes. 2. The washing tank according to claim 1, wherein an outer edge of each of the second straightening holes is adjacent to a lower surface of the straightening upper lid.