JPH10180203A - Ultrasonic washer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic washer in which sound pressure outputted from a vibrator is effectively increased even if total power is suppressed low. SOLUTION: This ultrasonic washer is provided with a device body 11 to which washing liquid is fed, a vibrator 24 fitted to a vibration plate installed in the device body 11, an ultrasonic oscillator 31 electrically connected to the vibrator 24 and for driving the vibrator 24 to subject it to ultrasonic vibration, an impedance matching circuit 33 installed between the ultrasonic oscillator 31 and the vibrator 24 for matching them, and an injected voltage measuring means 44 for measuring voltage injected to the vibrator 24. The ultrasonic oscillator 31 is provided with a control means for outputting voltage having an arbitrary wave shape according to the injected voltage measured by the injected power measuring means 44.

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 used 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 liquid crystal manufacturing apparatus or a semiconductor manufacturing apparatus, there is a process required to clean an object to be cleaned such as a glass substrate for a liquid crystal or a semiconductor wafer with high cleanliness. As a method of cleaning the 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 the cleaning liquid is sprayed toward the object to be cleaned to wash one by one. In addition to obtaining high cleanliness, a single-wafer method which is advantageous in terms of cost is often used.

[0003] As one of the single-wafer methods, a cleaning method has been put to practical use in which ultrasonic vibration is applied to a cleaning liquid sprayed on a cleaning object to thereby efficiently remove fine particles from the cleaning object by vibrating action. ing.

The vibration applied to the cleaning liquid has conventionally been 20 to 50 k.
Hz, but recently 600-2000 kHz
An ultrasonic cleaning device that applies a sound wave in the ultra-ultrasonic band of about z has been developed.

The ultrasonic cleaning apparatus has an apparatus main body, and the apparatus main body is provided with a diaphragm on which a vibrator is attached. An ultrasonic oscillator is connected to the vibrator. The ultrasonic oscillator outputs power of a predetermined frequency and applies the power to the vibrator. Accordingly, the vibrator vibrates ultrasonically, and the vibrating plate is linked to the ultrasonic vibration, and the vibrating plate applies ultrasonic vibration to the cleaning liquid.

[0006]

As a power supply to the vibrator, a continuous wave as shown in FIG. 4A or an AC power supply as shown in FIG. 4B is generally rectified. The used burst wave is used.

For example, if an attempt is made to increase the sound pressure of an ultrasonic wave generated from the vibrator using a continuous wave, the total power will increase. However, if an attempt is made to increase the sound pressure of an ultrasonic wave with a continuous wave, the total power is increased, and the sound pressure power is limited.

The present invention has been made in view of the above points, and an object of the present invention is to provide an ultrasonic cleaning apparatus capable of efficiently increasing the sound pressure output from a vibrator even when the total power is kept low. It is in.

[0009]

According to a first aspect of the present invention, there is provided an ultrasonic cleaning apparatus for applying an ultrasonic vibration to a cleaning liquid to clean an object to be cleaned. A vibrator attached to a vibrating plate provided in the apparatus main body, an ultrasonic oscillator electrically connected to the vibrator and driving the vibrator to ultrasonically vibrate; Provided between the vibrator and
An impedance matching circuit between the vibrator and the ultrasonic oscillator; and incident power measuring means for measuring power incident on the vibrator, wherein the ultrasonic oscillator is measured by the incident power measuring means. Control means for outputting a voltage having an arbitrary waveform in accordance with the incident power.

According to a second aspect of the present invention, there is provided an ultrasonic cleaning apparatus comprising: a high-frequency oscillator for outputting a continuous high-frequency signal; a driver amplifier connected to an output of the high-frequency oscillator; Central processing means for outputting a waveform shaping signal to the driver amplifier so that the measured power is obtained.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The ultrasonic cleaning apparatus of the present invention shown in FIG. This device body 11
An upper member 13 having a concave portion 12 with an open upper surface formed along the longitudinal direction, and a lower member 15 fixedly joined to the lower surface of the upper member 13 through a first seal member 14 in a liquid-tight manner. It is formed in the shape of an elongated prism.

A fitting hole 16 is formed along the longitudinal direction at the center of the lower wall of the upper member 13 in the width direction, and the fitting hole 16 is formed at the center of the upper surface of the lower member 15 in the width direction. A convex portion 17 to be fitted is 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 central portion in the width direction of the lower member 15 where the convex portion 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 vibrating plate 21 formed in a rectangular plate shape with tantalum, titanium or an alloy thereof. That is, the diaphragm 21 is joined to the inner bottom surface of the concave portion 12 of the upper member 13 through the frame-shaped second seal member 22 having a predetermined thickness at the lower peripheral portion.

A frame-like holding plate 23 is joined to the upper surface of the vibration plate 21 and is fixed to the upper member 13 by screws 20. Thereby, the upper end opening of the space 18 is liquid-tightly closed.

A central portion in the width direction of the upper surface of the diaphragm 21;
That is, the vibrator 24 is attached to a portion corresponding to the space 18 along the longitudinal direction of the diaphragm 21. A power supply plate 25 is attached to the press plate 23 via a holding member 26 above the vibration plate 21. The power supply plate 25 is provided with a leaf spring-like contact 27 that is in elastic contact with the vibrator 24.

The power supply plate 25 is provided with a coil 28 having one end (lower end) electrically connected thereto. This coil 2
At the other end (upper end side) of the electrode 8, an electrode 29 is provided so as to be slidable and fixable at an arbitrary sliding position.

The other electrode of the vibrator 24 is
The holding plate 23 is electrically connected to the holding plate 23, and one end of the second cable 30b of the coaxial cable 30 is connected to the holding plate 23. The other ends of these cables 30a and 30b are connected to an ultrasonic oscillator 31 for driving the vibrator 24 to perform ultrasonic vibration. In addition, the device main body 11 has the first
A variable condensin 32 is provided between the cable 30a and the second cable 30b to form a matching circuit 33 for ultrasonically vibrating the vibrator 24 as shown in FIG. ing. That is, the matching circuit 33
And the ultrasonic oscillator 31 are connected by a coaxial cable 30.

Accordingly, by sliding the electrode 29 to adjust the inductance of the coil 28 in the matching circuit 33 or the reactance of the variable capacitor 32, the ultrasonic oscillator 31 and the vibrator 24 are adjusted.
Impedance matching can be performed.

In the lower member 15 of the apparatus main body 11, a pair of supply paths 34 located on both sides in the width direction of the space 18 are formed penetrating in the longitudinal direction. A supply source (not shown) is connected to both ends of the supply path 34 via a tube (not shown) to supply a cleaning liquid such as pure water or a chemical solution.

Each of the pair of supply paths 34 is provided with a plurality of ejection paths 35 (only one is shown), one end of which is communicated. That is, the ejection path 35 is formed at a portion where the upper member 13 and the lower member 15 of the apparatus main body 11 are joined,
The other end is opened so as to communicate with a portion of the inner bottom surface of the concave portion 12 of the upper member 13 covered by the vibration plate 21, that is, the upper end side of the space 18. A plurality of the ejection paths 35 are formed at predetermined intervals along the longitudinal direction of the apparatus main body 1 on one side and the other side in the width direction of the space 18.

The ultrasonic oscillator 31 has a frequency synthesizer 41 as shown in FIG. The frequency synthesizer 41 outputs a continuous high-frequency voltage. The high frequency voltage output from the frequency synthesizer 41 is supplied to a high frequency power amplifier 43 via a driver amplifier 41a.
Connected to. The high-frequency power amplifier 43 amplifies a high-frequency voltage output via the driver amplifier 41a,
The voltage is output to a CM coupler (pass-through power meter) 44 for monitoring the voltage and current of the coaxial cable 30 having a resistance of 50Ω.
The output of the CM coupler 44 is supplied to the matching circuit 3
3 is output.

The CM coupler 44 measures the forward voltage Vf and the reflected voltage Vr. And this CM coupler-44
The traveling voltage Vf measured at is squared through the squaring circuit 51 and then input to the A / D converter 52. That is, the traveling power is measured by the squaring circuit 51. The advancing power output from the squaring circuit 51 is converted into digital data by the A / D converter 52, and then converted by the CPU.
42. The CPU 42 comprises a microcomputer and its peripheral circuits.
The peripheral circuit includes a D / A converter 42a. The output of the D / A converter 42a is output to the driver amplifier 41a. This driver amplifier 4
1a shapes the waveform of the continuous high-frequency voltage output from the frequency synthesizer 41 according to the output of the D / A converter 42a, and outputs it to the high-frequency amplifier 43. At this time, the CPU 42 controls the D / A so that the waveform-shaped high-frequency power output via the driver amplifier 41a becomes the traveling power input via the A / D converter 52.
The converter 42a is controlled.

The CM coupler 44 can check the matching between the ultrasonic oscillator 31 and the vibrator 24 according to the following principle. That is, the measured voltage is represented by C
The partial pressure is set to V _{v in} phase with the partial pressure. Mutual induction M bonds in the secondary circuit sucrose - DOO conditions, i.e. by passing a secondary current to a sufficiently low resistance current transformer, making the voltage V _i of the current having the same phase. And, if you check the matching is checked by whether V _v -V _i is 0. In other words, the fact that the phases match when V / I = 50Ω means that the matching is achieved.

Next, a case where the ultrasonic cleaning apparatus having the above configuration is used will be described. First, impedance matching between the ultrasonic oscillator 31 and the vibrator 24 is performed in order to efficiently vibrate the vibrator 24 before actually using the ultrasonic cleaning apparatus having the above configuration. That is, the ultrasonic oscillator 31 is operated to cause the oscillator 24 to oscillate ultrasonically, and at this time, the ultrasonic oscillator 31 and the oscillator 2
4 is measured by the CM coupler 44 to determine whether or not impedance matching with 4 is achieved.

When the matching is not achieved, the electrode 29 provided on the winding of the coil 28 is slid along the winding to adjust the inductance in the matching circuit 33 and the variable capacitor 32 is adjusted. Similarly, the reactance in the matching circuit 33 is adjusted, and the impedance between the ultrasonic oscillator 31 and the vibrator 24 is adjusted.
Match the dance.

The CPU 42 controls the driver amplifier 4
1a, the waveform-shaped high-frequency power output via
The D / A converter 42a is controlled so that the traveling power is inputted through the A / D converter 52.

As a result, as shown in FIG. 2, even non-continuous high-frequency power can be controlled so as to be forward power input through the A / D converter 52. As described above, by shaping the waveform of the power input to the vibrator 24, a waveform having a high crest can also be shaped. Therefore, a waveform having a high total power can be obtained even if the total power input to the vibrator 24 is small. Therefore, the vibrator 2
4, the sound pressure of the ultrasonic waves generated from the vibrator 24 can be increased.

[0029]

According to the first aspect of the present invention, a waveform having a high peak value of the voltage waveform supplied to the vibrator is formed, so that the output from the vibrator can be efficiently performed even if the total power is suppressed low. It is possible to provide an ultrasonic cleaning device capable of increasing the sound pressure to be performed.

According to the second aspect of the present invention, since the ultrasonic oscillator has the function of shaping the waveform, the total power supplied to the vibrator is kept low, and the sound pressure of the ultrasonic wave output from the vibrator is reduced. Can be raised.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram used for an ultrasonic cleaning apparatus according to an embodiment of the present invention.

FIG. 2 is a waveform chart according to the embodiment.

FIG. 3 is a schematic configuration diagram of the ultrasonic cleaning apparatus shown in the embodiment.

FIG. 4 is a waveform diagram conventionally input to a vibrator.

[Explanation of symbols]

Device main body, 21: diaphragm, 24: vibrator, 28: coil, 41: frequency synthesizer, 41a: driver amplifier, 42: CPU, 42a: D / A converter, 43:
High frequency amplifier, 44 ... CM coupler, 51 ... Squaring circuit, 52 ... A / D converter.

Claims (2)

[Claims] 1. An ultrasonic cleaning apparatus for applying an ultrasonic vibration to a cleaning liquid to clean an object to be cleaned, comprising: an apparatus main body to which the cleaning liquid is supplied; and a vibration plate provided on the apparatus main body. A vibrator, an ultrasonic oscillator electrically connected to the vibrator and driving the vibrator to ultrasonically vibrate; and an ultrasonic oscillator provided between the ultrasonic oscillator and the vibrator. An impedance matching circuit with an acoustic wave oscillator, and incident power measuring means for measuring electric power incident on the vibrator, wherein the ultrasonic oscillator responds to incident power measured by the incident power measuring means. An ultrasonic cleaning apparatus comprising a control unit for outputting a voltage having an arbitrary waveform. 2. An ultrasonic oscillator, comprising: a high-frequency oscillator for outputting a continuous high-frequency signal; a driver amplifier connected to an output of the high-frequency oscillator; and a power measured by the incident power measuring means. 2. The ultrasonic cleaning apparatus according to claim 1, further comprising central processing means for outputting a waveform shaping signal to said driver amplifier.