JP2001246319A - Ultrasonic oscillation device and ultrasonic oscillation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic oscillation device constituted in such a manner that various oscillation waveforms may be combined in order to enhance the cleaning effect of an object to be cleaned. SOLUTION: A high-frequency oscillator of the ultrasonic oscillation device which outputs high-frequency electric power to vibrate a high-frequency vibrator 12 is provided with a first switch 48 for selectively setting the wavelength of the high-frequency electric power outputted from the high-frequency oscillator at continuous waves and pulse waves.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-frequency oscillation device and a high-frequency oscillation method for causing a high-frequency oscillator to vibrate at a high frequency.

[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 an object to be cleaned such as a glass substrate 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.

As one of the single-wafer systems, a cleaning system has been put to practical use in which high-frequency vibration is applied to a cleaning liquid sprayed on a cleaning object and particles are efficiently removed from the cleaning object by vibrating action. I have.

[0004] Conventionally, the vibration applied to the cleaning liquid is 20 to 5 times.
It was a high frequency of about 0 kHz, but recently 600 to 2
A high-frequency cleaning device that applies a sound wave in an extremely high-frequency band of about 000 kHz has been put to practical use.

The high-frequency cleaning device has a high-frequency oscillator for outputting high-frequency power, and the high-frequency oscillator output from the high-frequency oscillator drives the high-frequency oscillator. The vibration of the high frequency oscillator is applied to the cleaning liquid. As a result, the object to be cleaned is subjected to high frequency cleaning.

[0006]

In the conventional ultrasonic oscillator, the waveform of the output high-frequency power is set to either a continuous wave or a pulse wave. Even if the waveform of the high-frequency power is a continuous wave or a pulse wave, a certain cleaning effect can be obtained.

However, depending on the contamination state of the object to be cleaned, that is, the degree and size of the particles adhering to the object to be cleaned, it is not sufficient to apply only one of the continuous wave and the pulse wave to the cleaning liquid. In some cases, the effect was not obtained.

[0008] For example, when a large amount of particles having a high adhesive force adhere to the object to be cleaned, it is preferable to perform cleaning with a pulse wave having a larger impact force applied to the object to be cleaned than a continuous wave.

However, if the object to be cleaned is continuously cleaned only by the pulse wave, a fine circuit pattern formed on the object to be cleaned may be damaged. Therefore, it is conceivable to wash the object to be cleaned for a short time with a pulse wave.However, if the cleaning time is short, the cleaning effect may be reduced. It is required to perform cleaning for a certain time or more by a continuous wave having a low impact force to obtain a predetermined cleaning effect.

That is, in order to enhance the cleaning effect, not only the pulse wave and the continuous wave are selected according to the contamination state such as the degree and size of the particles adhering to the object to be cleaned, but also the pulse wave and the continuous wave are selected. It is effective to wash the object to be cleaned by appropriately combining the waves with each other. However, in the conventional ultrasonic oscillator, only one of the pulse wave and the continuous wave can be obtained as described above. However, it has not been possible to wash the object to be cleaned in an optimum state according to the contamination state of the object to be cleaned.

An object of the present invention is to improve the cleaning effect by selecting or combining a continuous wave and a pulse wave in accordance with the contamination state of the object to be cleaned, such as the type and shape of particles attached to the object to be cleaned. An ultrasonic oscillation device and a high-frequency oscillation direction that can be caused to be provided.

[0012]

According to a first aspect of the present invention, there is provided an ultrasonic oscillator including a high-frequency oscillator for outputting high-frequency power for oscillating a high-frequency oscillator, wherein the high-frequency oscillator outputs a signal from the high-frequency oscillator. An ultrasonic oscillator provided with a first switch for selectively setting the waveform of the high-frequency power to a continuous wave or a pulse wave.

According to a second aspect of the present invention, the high-frequency oscillator has a control unit, and the control unit controls the switching of the first switch and outputs a continuous wave and a pulse wave of a high-frequency power waveform. 2. The ultrasonic oscillator according to claim 1, wherein a combination of the following is set.

According to a third aspect of the present invention, in the high frequency oscillator, a second switch for setting an oscillation frequency according to an impedance characteristic of the high frequency oscillator, an oscillation time of high frequency power output from the high frequency oscillator, and The ultrasonic oscillator according to claim 1, further comprising a third switch for setting an oscillation interval.

According to a fourth aspect of the present invention, in the ultrasonic oscillating apparatus according to the first aspect, the high-frequency oscillator is provided with a fourth switch for frequency-modulating the frequency of vibration of the high-frequency power. is there.

According to a fifth aspect of the present invention, there is provided an ultrasonic oscillator including a high-frequency oscillator for outputting high-frequency power for oscillating a high-frequency oscillator, wherein the high-frequency oscillator is provided with high-frequency power according to impedance characteristics of the high-frequency oscillator. An ultrasonic oscillator is provided with a switch for frequency-modulating the frequency of vibration.

According to a sixth aspect of the present invention, there is provided a high-frequency oscillation method for generating high-frequency power for vibrating a high-frequency oscillator, wherein a step of selectively setting a waveform of the high-frequency power to a continuous wave or a pulse wave; Setting a combination of a continuous wave and a pulse wave having the following waveforms.

According to the first aspect of the present invention, the high frequency power waveform is selectively set to a continuous wave or a pulse wave by the first switch, and the object to be cleaned is cleaned with a high frequency vibration having a desired waveform. it can.

According to the second aspect of the present invention, control is performed by the switching control section of the first switch.
The combination of the continuous wave and the pulse wave of the high-frequency power waveform can be performed automatically and arbitrarily.

According to the third aspect of the invention, the oscillation frequency can be set according to the impedance characteristics of the high-frequency vibrator by the second switch, and the level of the high-frequency power can be set by the third switch. .

According to the fourth and fifth aspects of the present invention, the fourth aspect
Since the frequency of the vibration of the high-frequency power can be frequency-modulated by the switch, the oscillation efficiency of the high-frequency vibrator can be improved.

According to the sixth aspect of the present invention, since the high-frequency power waveform can be arbitrarily combined with a continuous wave and a pulse wave, cleaning is performed with a high-frequency vibration having an optimum waveform according to the contamination state of the object to be cleaned. It is possible to do.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

The ultrasonic oscillator of the present invention shown in FIGS. 1 and 2 has a high-frequency oscillator 31 to which the high-frequency cleaner 10 is connected via a matching circuit 27.

[0025] As shown in FIG.
Has a body 11. The main body 11 has an upper member 13 having a concave portion 12 with an open upper surface formed along the longitudinal direction, and a lower member fixed to the lower surface of the upper member 13 in a liquid-tight manner via a first seal member 14. The member 15 forms 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 to the upper surface and the other end opened to 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 portion 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 nozzle opening narrower than the upper end. 19 is formed. The cleaning liquid is supplied to the space 18 from a pair of supply paths 20 formed in the lower member 15.

The open upper end of the space 18 is closed in a liquid-tight manner 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 20a. 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, a high-frequency vibrator 24 is attached to a portion corresponding to the space 18 along the longitudinal direction of the diaphragm 21. The high-frequency vibrator 24 has, for example, a resistance of 50Ω.
One end of the core wire of the first coaxial cable 25a is electrically connected. A first socket 26a is provided at the other end of the first coaxial cable 25a, and the first socket 26a is detachably attached to a first port 27a provided at one end of the matching circuit unit 27. Connected to. The first
Of the coaxial cable 25a is grounded.

The other end of the matching circuit section 27 has a second
A second socket 27b provided at one end of a second coaxial cable 25b is detachably connected to the second port 27b. The other end of the second coaxial cable 25b is connected to the high frequency oscillator 31. This high-frequency oscillator 31 has a frequency synthesizer 32 as shown in FIG. This frequency synthesizer 3
2 outputs a waveform of a predetermined frequency, and the frequency is converted and controlled by the CPU 33 as a control unit.

A waveform of a predetermined frequency output from the frequency synthesizer 32 is amplified by a high-frequency power amplifier 34, and a CM coupler (pass-through power meter) for monitoring the voltage and current of the second coaxial cable 25b. The output is monitored at 35) and output to the matching circuit 27.

FIG. 4 shows a detailed configuration of the high-frequency oscillator 31. That is, the AC 100 V from the power supply 41 is input to the rectifier 46 for full-wave rectification of the AC 100 V through the fuse 43, the switch 44, and the breaker 45 after the noise is removed by the filter 42.

The power rectified by the rectifier 46 is input to an electrolytic capacitor 47. This electrolytic capacitor 47
Is provided with a first switch 48. The first switch 48 is automatically switched between the continuous side and the pulse side by the CPU 33.
When switched to the pulse side, the full-wave rectified power passes through the electrolytic capacitor 47, so that it becomes a pulse waveform and is input to the power amplifier 34. When switched to the continuous side, the power is converted into a continuous waveform by the electrolytic capacitor 47 and The signal is input to the amplifier 34.

The power amplifier 34 has a volume 34a.
And a PLL circuit 5 for generating high frequency components
1 is connected. A second switch 52 is connected to the PLL circuit 51. This second switch 52
Is for setting the oscillating frequency of the high-frequency power output from the power amplifier 34. In this embodiment, the oscillating frequency of the power is set to 1600 kHz high-frequency power.

CPU 3 to which PLL circuit 51 is connected
3 is provided with a third switch 53 for controlling the oscillation time and oscillation interval (duty ratio) of the high-frequency power output from the power amplifier 34. The duty ratio of the high-frequency power can be controlled by the third switch 53.

That is, when a continuous wave is output from the power amplifier 34, if the duty ratio set by the third switch 53 is 0, a continuous wave is obtained. However, if the duty ratio is set to a predetermined value, As shown in FIG. 5F, a burst wave obtained by dividing a continuous wave at a predetermined period can be obtained. Further, when a pulse wave is output from the power amplifier 34, if the duty ratio is changed by the third switch 53, the power level of the pulse wave can be adjusted.

The traveling wave and the reflected wave of the high-frequency power output from the power amplifier 34 are detected by the VSWR detector 54. The detection signal from the VSWR detector 54 is processed by a calculation circuit 55 and fed back to the power amplifier 34 and the CPU 33. Power amplifier 3
At 4, the signal from the arithmetic circuit 55 causes the volume 3
Based on the setting of 4a, the power of the high-frequency power oscillated from the power amplifier 34 is corrected.

Further, a low-frequency oscillation circuit 57 is connected to the PLL circuit 51 via a fourth switch 56. When the fourth switch 56 is turned on, the PLL
The high-frequency power oscillated and output from the power amplifier 34 via the circuit 51 is frequency-modulated based on the frequency generated by the low-frequency oscillating circuit 57. In the present embodiment, 1 is set by the second switch 52.
The output frequency of high-frequency power of 600 kHz is 1590 to 1
Frequency modulation is performed in the range of 610 kHz.

Thus, even if the impedance characteristics of the high-frequency vibrator 24 are partially non-uniform, the sound pressure of the high-frequency vibration output from the high-frequency vibrator 24 can be made uniform.

That is, since the high-frequency vibrator 24 is usually manufactured by compression-molding and sintering a powdery ceramic raw material, it is difficult for the impedance characteristic to be constant throughout the entire region. Therefore, even when high-frequency power of a predetermined frequency is uniformly supplied to the entire region of the high-frequency vibrator 24, the output may not be constant.

However, the high-frequency power supplied to the high-frequency vibrator 24 is frequency-modulated in a predetermined frequency range. Since high-frequency power having a different frequency can be supplied, the intensity of ultrasonic waves output from the high-frequency vibrator 24 can be made substantially uniform.

The frequency generated by the low-frequency oscillation circuit 57 can be set by a potentiometer 58.

As shown in FIG.
Is provided with a timer 61 and a relay circuit 62.
The timer 61 measures the oscillation time, and is provided with a reset switch 63 for resetting the measurement time. The relay circuit 62 performs various displays using a plurality of lamps 64.

The first to fourth switches 48, 48
The operations of 52, 53, and 56 can be automatically operated by the CPU 33.

A part of the electric power from the power supply 41 is
Fan 65 and CP for cooling high-frequency oscillator 31
It is designed to be input to a converter 66 for converting an AC voltage to a DC voltage to drive U33.

Next, FIG.
A case in which high-frequency power having the waveforms shown in FIGS.

First, when the high-frequency power having the first waveform shown in FIG. 5A is output, the switch 33 is turned on and the power is turned on, and the CPU 33 outputs the first waveform. Set to. Based on the setting of the CPU 33, the first switch 48 switches to the pulse side at the beginning of the oscillation when the oscillation operation is started, and switches to the continuous side at the same time as the end of the pulse oscillation (one-pulse oscillation in this embodiment).

As a result, at the initial stage of the oscillation when the first switch 48 is switched to the pulse side, the electric power which is full-wave rectified by the rectifier 46 passes through the electrolytic capacitor 47.
From the power amplifier 34, high-frequency power of the frequency set by the second switch 52 is pulse-oscillated.

When the pulse oscillation of the high-frequency power is completed, the first switch 48 switches to the continuous side, so that the rectifier 4
The power that has been full-wave rectified in 6 is smoothed by an electrolytic capacitor 47 and input to the power amplifier 34.

As a result, the power from the electrolytic capacitor 47 continuously oscillates at a lower power level than the pulse oscillation and at a frequency based on the setting of the second switch 52. In other words, the first waveform is pulse oscillation at the beginning of oscillation, and is continuous oscillation thereafter.

When such a waveform of the first high-frequency power is input to the high-frequency vibrator 24, the object to be cleaned can be cleaned at first with high-power pulse oscillation, and thereafter cleaned with low-power continuous oscillation for a predetermined time. be able to.

For this reason, it is possible to remove particles having a relatively large size from the object to be cleaned by the first pulse oscillation, because the particles are relatively hard to adhere and fall off.
Next, by continuously performing continuous oscillation for a predetermined time, it is possible to reliably remove particles that cannot be removed in a short time, such as particles that adhere to an object to be cleaned in a normal state and particles having a relatively small particle diameter. it can.

When outputting the high frequency power waveform of the second waveform shown in FIG. 5B, the CPU 33 is set to a state where the second waveform is output. When the oscillating operation is started based on the setting of the CPU 33, first, the first switch 48 is switched to the continuous side until a predetermined time has elapsed since the oscillating operation started.

As a result, the electric power that has been full-wave rectified by the rectifier 46 continuously oscillates based on the frequency set by the second switch 52. When continuous oscillation is performed for a predetermined time,
Since the first switch 48 is switched to the pulse side,
The power rectified by the rectifier 46 is supplied to the electrolytic capacitor 4
7 and pulse oscillation is performed at a predetermined frequency.

Therefore, according to such an oscillation waveform, most particles adhering to the object to be cleaned are removed by continuous oscillation for a predetermined time, but particles that are not removed by continuous oscillation are removed by the last pulse oscillation. Therefore, in this case, as in the case of the first waveform, a sufficient cleaning effect can be obtained even if the state and size of the particles adhered to the object to be cleaned are not constant.

When outputting the third high-frequency power waveform shown in FIG. 5C, the CPU 33 is set to a state where the third waveform is output. When the oscillation is started based on the setting of the CPU 33, the first switch 48 is switched from the continuous side to the pulse side at predetermined time intervals by a control signal from the CPU 33.

As a result, the waveform of the third high-frequency power is such that pulse oscillation and continuous oscillation are repeated. When the waveform 3 is applied, the cleaning effect can be enhanced without giving an excessive impact to the object to be cleaned, as compared with the case where the object to be cleaned is cleaned only by pulse oscillation.

The fourth waveform shown in FIG. 5D is a continuous wave, and when the CPU 33 is set to output this waveform, the first switch 48 is switched to the continuous side. As a result, the power that has been full-wave rectified by the rectifier 46 is smoothed by the electrolytic capacitor 47 and input to the power amplifier 34, so that continuous oscillation based on the frequency set by the second switch 52 is performed.

When the continuous wave having the fourth waveform is oscillated, if the duty ratio is set from 0 to a predetermined value by the third switch 53, as shown in FIG. , A burst wave divided at a period of can be obtained. This cycle can be arbitrarily set by the duty ratio. Note that the waveform in FIG. 5F is a sixth waveform.

The fifth waveform shown in FIG. 5E is a pulse wave, and when the CPU 33 is set to output this waveform, the first switch 48 is switched to the pulse side. As a result, the power that has been full-wave rectified by the rectifier 46 passes through the electrolytic capacitor 47 and is input to the power amplifier 34, so that pulse oscillation based on the frequency set by the second switch 52 is performed.

When the pulse wave having the fifth waveform is oscillated, if the duty ratio is set to a predetermined value by the third switch 53, the output level of the pulse wave can be adjusted. The object to be cleaned can be cleaned at an output level suitable for the dirty state of the object.

As described above, since the switching of the first switch 48 is controlled by the CPU 33, an oscillation waveform combining a pulse wave and a continuous wave can be obtained.
By setting the oscillation waveform in accordance with the type and size of the particles attached to the object to be cleaned, the cleaning effect can be improved.

Moreover, not only the first to third waveforms combining the pulse wave and the continuous wave, but also the fourth waveform of the continuous wave and the fifth waveform of the pulse wave alone can be oscillated. Even when the first to third waveforms cannot cope, it is possible to cope.

Further, if the duty ratio is set by the third switch, a burst wave can be obtained from the continuous wave when a continuous wave is oscillated, and the output level of the pulse wave is changed when a pulse wave is oscillated. Therefore, an oscillation waveform corresponding to various cleaning conditions can be set.

When the high frequency power is oscillated with the first to sixth waveforms, the high frequency power oscillated and output from the power amplifier 34 can be FM-modulated by turning on the fourth switch 56 by the CPU 33. In the case of this embodiment, high-frequency power oscillated at a frequency of 1600 kHz can be modulated in a range of 1590 to 1610 kHz.

Therefore, even if the impedance characteristics of the high-frequency vibrator 24 to which the high-frequency power is supplied are not uniform over the entire region, the intensity of the vibration output from the high-frequency vibrator 24 can be made substantially constant. This makes it possible to uniformly clean the object to be cleaned.

Since the potentiometer 58 is connected to the low frequency oscillation circuit 57 for producing the frequency of the frequency modulation,
The frequency generated by the low frequency oscillation circuit 57 can be set by the potentiometer 58. That is, high-frequency power can be frequency-modulated in a range other than 1590 to 1610 kHz.

[0069]

As described above, according to the present invention, the high-frequency power output from the high-frequency oscillator can be oscillated by one or a combination of a continuous wave and a pulse wave.

Therefore, the cleaning effect can be enhanced by controlling the oscillation waveform of the high-frequency power supplied to the high-frequency vibrator according to the contamination state of the object to be cleaned.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an ultrasonic oscillator according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the high frequency cleaning machine.

FIG. 3 is a schematic diagram of a high-frequency oscillator.

FIG. 4 is a circuit diagram of a high-frequency oscillator.

FIG. 5 is an explanatory diagram of a waveform obtained by a high-frequency oscillator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 31 ... High frequency oscillator 33 ... CPU (control part) 48 ... 1st switch 52 ... 2nd switch 53 ... 3rd switch 56 ... 4th switch

Claims (6)

[Claims] 1. An ultrasonic oscillator comprising a high-frequency oscillator for outputting high-frequency power for oscillating a high-frequency vibrator, wherein the high-frequency oscillator includes a continuous wave and a pulse wave for the high-frequency power output from the high-frequency oscillator. And a first switch for selectively setting the ultrasonic oscillator is provided. 2. The high-frequency oscillator has a control unit, which controls the switching of the first switch and sets a combination of a continuous wave and a pulse wave of the output high-frequency power waveform. The ultrasonic oscillator according to claim 1, wherein: A second switch for setting an oscillation frequency according to an impedance characteristic of the high-frequency oscillator; and a second switch for setting a time and an oscillation interval of high-frequency power output from the high-frequency oscillator. The ultrasonic oscillator according to claim 1, further comprising three switches. 4. The ultrasonic oscillator according to claim 1, wherein the high-frequency oscillator is provided with a fourth switch for frequency-modulating the frequency of the vibration of the high-frequency power. 5. An ultrasonic oscillator comprising a high-frequency oscillator for outputting high-frequency power for vibrating a high-frequency oscillator, wherein the high-frequency oscillator has a frequency of a waveform of the high-frequency power according to an impedance characteristic of the high-frequency oscillator. An ultrasonic oscillator, comprising a switch for modulating. 6. A high-frequency oscillation method for generating high-frequency power for vibrating a high-frequency vibrator, wherein a step of selectively setting a waveform of the high-frequency power to a continuous wave or a pulse wave; And a step of setting a combination of pulse waves.