JPH0919666A - Ultrasonic washing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deformation of a diaphragm by a washing liquid pressure by providing the above device with a pressure regulating means for maintaining the inside of a space part at a prescribed pressure by relieving part of the washing liquid when the washing liquid supplied into this space part attains the pressure higher than the prescribed pressure. SOLUTION: The washing liquid is supplied from a supply path 31 via an ejection path 32 to the space port 18. Since the rate of the washing liquid supplied into the space part 18 is set higher than the outflow rate from a nozzle part 19, the pressure in the space part 18 increases gradually. The spherical body 36 of a check valve 34 is depressed by the pressure when the pressure in the space part 18 attains the prescribed value and the top end of a discharge path is opened, therefore, the washing liquid is partly relieved therefrom. As a result, the pressure of the washing liquid in the space part 18 is maintained constant. The power feed to a vibrator 24 is started by a controller 30 when the discharge of the washing liquid is detected by a sensor 41. The diaphragm 21 is then ultrasonically vibrated and the wash is efficiently washed by the washing liquid applied with the ultrasonic vibration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic cleaning apparatus for applying ultrasonic vibration to a cleaning liquid for cleaning an object to be cleaned.

[0002]

2. Description of the Related Art For example, in a process of manufacturing a liquid crystal display device or a semiconductor device, there is a process that requires cleaning a liquid crystal glass substrate or a semiconductor wafer as an object to be cleaned with high cleanliness. As a method of cleaning such an object to be cleaned, there are a dip method in which a plurality of objects to be cleaned are immersed in a cleaning liquid, and a single-wafer method in which a cleaning liquid is sprayed toward the object to be cleaned to wash one by one, In recent years, a single-wafer method which is advantageous in terms of cost while being able to obtain high cleanliness has been increasingly used.

[0003] As one of the single-wafer systems, a cleaning system has been put to practical use in which vibration is imparted to a cleaning liquid sprayed on a cleaning object, and the fine particles are efficiently removed from the cleaning object by vibrating action. .

In the cleaning method of applying vibration to the cleaning liquid, an ultrasonic wave of about 20 to 50 kHz has been used in the past, but recently an ultrasonic cleaning apparatus using an ultrasonic wave in an ultra-ultrasonic band of about 600 to 1.5 MHz has been developed. Is being developed.

[0005] When the vibration-applied cleaning liquid is sprayed onto the object to be cleaned, the effect of the vibration reduces the bonding force of the fine particles adhering to the object to be cleaned, so that the cleaning effect is improved as compared with the case where no vibration is applied. be able to.

Conventionally, the ultrasonic cleaning apparatus has a main body in which a space to which a cleaning liquid is supplied is formed. This space is open to one side of the apparatus main body, and the cleaning liquid is ejected from a nozzle port which is the opening.

A vibrating plate is provided on the apparatus main body in a state where the cleaning liquid supplied to the space contacts the vibrating plate, and a vibrator is attached to the vibrating plate. A voltage is supplied to the vibrator, whereby the diaphragm vibrates with the vibrator by ultrasonic vibration.

When the vibration plate vibrates ultrasonically, ultrasonic vibration is applied to the cleaning liquid that comes into contact with the vibration plate.
The object to be cleaned can be cleaned by the cleaning liquid which is applied with ultrasonic vibration and flows out from the nozzle opening.

Meanwhile, in a production factory or the like in which a number of ultrasonic cleaning devices and other devices using a cleaning liquid are installed, the cleaning liquid from a supply source is pressurized by a pump and the above-described number of ultrasonic vibration devices and other devices are used. It is distributed to devices. Therefore, it is inevitable that the pressure of the cleaning liquid supplied to the ultrasonic cleaning device fluctuates depending on the operation status of various devices.

For example, when the pressure of the cleaning liquid supplied to the space of the apparatus main body becomes higher than a predetermined value, the pressure is applied to the diaphragm. Since the diaphragm is made of a very thin metal plate so as to be easily subjected to ultrasonic vibration, there is a possibility that the diaphragm is deformed by the pressure.

When the pressure of the cleaning liquid supplied to the space falls below a predetermined value, air may flow into the space and remain. If the diaphragm is ultrasonically vibrated in such a state, ultrasonic vibration may be applied to the cleaning liquid from the diaphragm through an air layer remaining in the space, and in such a case, Since the ultrasonic vibration is not reliably transmitted from the diaphragm to the cleaning liquid, or a portion where the cleaning liquid does not come into contact with the ultrasonically vibrating diaphragm is generated and the cooling action by the cleaning liquid is impaired, the temperature of the diaphragm locally rises, There is a risk of thermal deformation.

[0012]

As described above, when the pressure of the supplied cleaning liquid rises, the conventional ultrasonic vibrating apparatus
There was a case where the diaphragm was deformed because an excessive pressure was applied to the diaphragm. In addition, when the pressure of the cleaning liquid supplied to the space decreases, the vibration plate may vibrate in an ultrasonic state with air remaining in the space, and the ultrasonic vibration of the vibration plate is reliably transmitted to the cleaning liquid. In some cases, the cooling operation of the diaphragm by the cleaning liquid is interrupted by the air layer, and the diaphragm generates heat locally.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent the pressure of the cleaning liquid from rising too much by allowing the cleaning liquid to escape from the space when the pressure of the cleaning liquid rises too much, An object of the present invention is to provide an ultrasonic vibration device capable of coping with the fact that when the pressure drops, it is detected.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an ultrasonic cleaning apparatus for applying ultrasonic vibration to a cleaning liquid for cleaning an object to be cleaned. A space formed to open on one side and allowing the cleaning liquid supplied therein to flow out of the opening; and an ultrasonic wave provided to the cleaning liquid provided in the apparatus body in contact with the cleaning liquid supplied to the space. A vibrating plate to which a vibrator for applying vibration is attached, and a part of the cleaning liquid escapes when the cleaning liquid provided in the apparatus main body and supplied to the space becomes a predetermined pressure or more, and the inside of the space is released. Pressure adjusting means for maintaining a predetermined pressure.

According to a second aspect of the present invention, in the first aspect of the present invention, a detecting means for detecting the cleaning liquid flowing out of the pressure adjusting means is provided. According to the first aspect of the present invention, when the cleaning liquid supplied to the space becomes a predetermined pressure or more, the cleaning liquid in the space escapes from the pressure adjusting means, so that the pressure in the space can be maintained constant. .

According to the second aspect of the present invention, a part of the cleaning liquid supplied to the space escapes from the pressure adjusting means, and it is detected that the cleaning liquid in the space is maintained at a constant pressure. In addition, the vibration plate can be vibrated only when the cleaning liquid in the space has a predetermined pressure or more.

[0017]

An embodiment of the present invention will be described below with reference to the drawings. The ultrasonic cleaning device of the present invention has a device main body 11. The apparatus main body 11 has an upper member 13 in which a concave portion 12 having an open upper surface is formed along the longitudinal direction.
And a lower member 15 joined and fixed in a liquid-tight manner to the lower surface of the upper member 13 via a first seal member 14 to form an elongated prism.

A fitting hole 16 is formed in the lower wall of the upper member 13 along the longitudinal direction, and a protrusion part fitted in the fitting hole 16 is formed in the widthwise central portion of the upper surface of the lower member 15. 17 are formed.

A space 18 having one end opened on the upper surface and the other end opened on the lower surface is formed along the longitudinal direction at the center of the lower member 15 in the width direction where the projection 17 is formed. . The cross-sectional shape of the space 18 is tapered such that the width decreases from one end (upper end) to the other end (lower end), and the lower end opening is a narrow nozzle opening 19. .

The open upper end of the space 18 is liquid-tightly closed by a diaphragm 21 made of a rectangular thin metal plate. That is, the vibrating plate 21 is joined to the inner bottom surface of the concave portion 12 of the upper member 13 through a frame-shaped second seal member 22 having a predetermined thickness at a lower peripheral portion thereof. It is provided with the lower surface facing the space 18.

A frame-like pressing plate 23 is also joined to the upper surface of the vibration plate 21 and is fixed to the upper member 13. Thereby, the upper end opening of the space 18 is liquid-tightly closed.

The central portion in the width direction of the upper surface of the diaphragm 21,
That is, a plurality of vibrators 24 made of piezoelectric elements are attached along the longitudinal direction of the vibrating plate 21 at a portion corresponding to the space 18.

Above the vibration plate 21, a power supply plate 25 is attached to the holding plate 23 via a holding member 26. The feed plate 25 is provided with a contactor 27 that elastically contacts the vibrator 24. A coil 28 is provided on the power supply plate 25, and a power supply 29 and a control device 30 are sequentially connected to the coil 28.

When a drive signal from the control device 30 is input to the power supply 29, the power supply 29
8. Power is supplied to the vibrator 24 via the power supply plate 25 and the contact 27. Thereby,
The vibrator 24 is ultrasonically vibrated, and the vibration plate 21 is interlocked with the ultrasonic vibration.

In the lower member 15 of the apparatus main body 11, a supply path 31 is provided on one side in the width direction of the space 18.
1 is formed along the longitudinal direction. This supply path 31
One end is opened at one longitudinal end surface of the device main body 11,
The other end of a water supply pipe 32a (shown in FIG. 3) having one end connected to a supply source of a cleaning liquid such as pure water or a chemical solution (not shown) is connected thereto.

Each of the supply paths 31 is provided with a plurality of ejection paths 32, one end of which is communicated. That is, the ejection path 32 is formed at a portion where the upper member 13 and the lower member 15 of the apparatus main body 11 are joined, and the other end is connected to the upper member 1.
An opening is formed so as to communicate with a portion of the inner bottom surface of the concave portion 12 covered by the vibration plate 21, that is, the upper end side of the space portion 18.

On the other side of the space 18 in the width direction, a plurality of discharge paths 33 are formed at predetermined intervals in the longitudinal direction. The upper end of the discharge passage 33 communicates with the upper part of the space, and the lower end is branched into two parts. One part 33 a is opened to the lower surface of the apparatus main body 11. A check valve 3 is provided above the discharge passage 33.
4 are provided.

The check valve 34 includes a housing 35 formed in the upper portion of the discharge passage 33, a sphere 36 stored in the housing 35, and a sphere 36 stored in the lower portion of the discharge passage 33, And a spring 37 that closes the upper end opening of the discharge path 33 by urging the discharge path 33. The discharge path 33
The lower end of the other side 33b is closed, and an adjusting screw 38 is screwed into the lower end. The adjusting screw 38 can adjust the urging force of the spring 36 by the spring 37.

The cleaning liquid supplied from the supply passage 31 to the space 18 through the ejection passage 32 flows out from the nozzle port 19 at the lower end of the space 18. The cleaning liquid is supplied to the nozzle port 19.
From the supply path 31 to the space 18
The space 18 is set to be filled with the cleaning liquid.

When the space 18 is filled with the cleaning liquid, the internal pressure gradually increases. When the pressure in the space 18 rises above a predetermined level, the ball 36 of the check valve 34 is
Is depressed to open the discharge path 33 and the cleaning liquid flows out therefrom, so that the pressure in the space 18 is kept constant.

The pressure of the cleaning liquid in the space 18, that is, the pressure at which the discharge passage 33 is opened, is increased by turning the adjusting screw 38 in the screwing direction and compressing the spring 37, and turning in the opposite direction. , The amount of compression of the spring 37 is reduced. That is, the discharge path 33, the check valve 34, and the adjusting screw 38 constitute pressure adjusting means for adjusting the pressure of the cleaning liquid in the space 18.

A sensor 4 serving as a detecting means for detecting whether or not the cleaning liquid is flowing through the discharge path 33 is provided.
1 is provided. The detection signal of the sensor 41 is input to the control device 30. When the sensor 41 detects that the cleaning liquid is flowing through the discharge path 33, the control device 30 outputs a drive signal for operating the power supply 29 based on the detection signal. Thereby, the power supply 29
Supplies power to the vibrator 24.

That is, when the cleaning liquid in the space 18 is discharged from the discharge passage 33 at a predetermined pressure, power is supplied to the vibrator 24 to ultrasonically vibrate the vibration plate 21. Is available.

Next, the operation of the ultrasonic cleaning apparatus having the above configuration will be described. The cleaning liquid is supplied to the space 18 from the supply path 31 via the ejection path 32. Since the amount of the cleaning liquid supplied into the space 18 is set to be larger than the amount of outflow from the nozzle port 19, the pressure in the space 18 gradually increases.

When the pressure in the space 18 reaches a predetermined value,
As shown in FIG. 4, the sphere 36 of the check valve 34 is pushed down by the pressure, and the upper end of the discharge path 33 is opened, so that a part of the cleaning liquid escapes therefrom. Thereby, the pressure of the cleaning liquid in the space 18 is kept constant.

When a part of the cleaning liquid flows out of the discharge path 33 and is detected by the sensor 41, the control device 30 activates the power supply 29 to supply power to the vibrator 24 by the detection signal. The plate 21 is ultrasonically vibrated, and the ultrasonic vibration is transmitted to the cleaning liquid. Therefore, since the cleaning liquid to which the ultrasonic vibration is applied flows out from the nozzle port 19, the object to be cleaned can be efficiently cleaned with the cleaning liquid.

When the pressure of the cleaning liquid in the space 18 exceeds a predetermined pressure, the check valve 34 opens and a part of the cleaning liquid escapes from the discharge passage 33, and the pressure in the space 18 is maintained at a constant level. Therefore, the pressure of the cleaning liquid in the space 18 is prevented from excessively increasing, and thus the diaphragm 21 is prevented from being deformed by the pressure of the cleaning liquid.

The power supply to the vibrator 24 is performed after the sensor 41 detects that the pressure in the space 18 has become equal to or higher than a predetermined value and a part of the cleaning liquid has flowed to the discharge path 33. Therefore, the diaphragm 21 does not vibrate ultrasonically when the pressure in the space 18 is not sufficiently increased.

That is, when the pressure in the space 18 does not rise sufficiently, air may remain in the space 18, but when the pressure in the space 18 is maintained at a predetermined value or more, the air remains. It is possible to prevent the diaphragm 21 from being ultrasonically vibrated while air remains inside. Thereby, it is possible to prevent the diaphragm 21 from being ultrasonically vibrated in a state where the air layer remains in the space 18, so that the diaphragm 21 partially generates heat or reduces the propagation efficiency of the ultrasonic vibration. Can be prevented.

[0040]

As described above, according to the first aspect of the present invention, when the pressure of the cleaning liquid supplied to the space of the apparatus main body becomes a predetermined value or more, a part of the cleaning liquid is allowed to escape and the inside of the space is increased. A pressure adjusting means for maintaining the pressure of 1 at a predetermined value is provided.

Therefore, it is possible to prevent the pressure of the cleaning liquid from excessively increasing in the space, and to prevent the diaphragm provided facing the space from being deformed due to the excessive increase in the pressure of the cleaning liquid. it can.

According to a second aspect of the present invention, in the first aspect of the present invention, the cleaning liquid flowing out of the pressure adjusting means is detected by the detecting means, so that the pressure in the space to which the cleaning liquid is supplied is equal to or higher than a predetermined value. Can be detected. Therefore, it is possible to perform control such that the diaphragm is ultrasonically vibrated only when the pressure in the space is equal to or higher than the predetermined value by the detection signal.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an ultrasonic cleaning apparatus according to an embodiment of the present invention.

FIG. 2 is a transverse sectional view taken along the line AA of FIG. 1;

FIG. 3 is a side view of the same.

FIG. 4 is an enlarged cross-sectional view of the pressure adjusting means showing a state in which the pressure in the space becomes equal to or higher than a predetermined value and a part of the cleaning liquid escapes a discharge path.

[Explanation of symbols]

11 ... device main body, 18 ... space part, 24 ... vibrator, 21 ...
Vibration plate, 31 ... Supply path, 32 ... Jet path, 33 ... Discharge path (pressure adjusting means), 34 ... Check valve (pressure adjusting means), 3
8 ... Adjusting screw (pressure adjusting means), 41 ... Sensor (detecting means).

Claims (2)

[Claims] 1. An ultrasonic cleaning device for applying ultrasonic vibration to a cleaning liquid for cleaning an object to be cleaned, comprising: a main body of the apparatus; A space part for flowing out from the opening, a vibration plate provided with a vibrator for providing ultrasonic vibration to the cleaning liquid provided in the apparatus body in contact with the cleaning liquid supplied to the space part, and And a pressure adjusting means which is provided in the main body of the apparatus and retains the inside of the space at a predetermined pressure by releasing a part of the cleaning liquid when the cleaning liquid supplied to the space exceeds a predetermined pressure. Characteristic ultrasonic cleaning device. 2. The ultrasonic cleaning apparatus according to claim 1, further comprising a detecting means for detecting a cleaning liquid flowing out of said pressure adjusting means.