JP3809296B2 - Ultrasonic cleaning equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic cleaning apparatus used for cleaning, for example, a semiconductor wafer or a glass substrate.
[0002]
[Prior art]
The ultrasonic cleaning device is capable of removing sub-micron particles (particulates), is free of damage to the cleaning object because cavitation does not occur, and has no influence of standing waves due to its short wavelength. Development has been promoted and put into practical use because of the fact that ultra-precision cleaning is possible, such as the ability to obtain a clean effect.
[0003]
As a conventional ultrasonic cleaning apparatus of this type, for example, there is a cleaning tank type shown in FIG. The ultrasonic cleaning apparatus shown in FIG. 5 is disclosed in JP-A-10-94756.
[0004]
FIG. 5 is a side view including a partial cross-section illustrating a conventional ultrasonic cleaning apparatus, and FIG. 6 is a perspective view including a partial cross-section illustrating a conventional ultrasonic vibration generator included in the conventional ultrasonic cleaning apparatus. It is. Hereinafter, a conventional ultrasonic cleaning apparatus (including an ultrasonic excitation apparatus) will be described with reference to FIGS. 5 and 6.
[0005]
As shown in FIG. 5, a conventional ultrasonic cleaning apparatus 110 is attached to, for example, a processing tank 102 that stores pure water 101 and stores an object to be cleaned as a cleaning fluid, and a bottom of the processing tank 102. And an ultrasonic vibration generator 103.
[0006]
As shown in FIG. 6, the ultrasonic vibration generating unit 103 includes a substantially rectangular parallelepiped waveguide 105 and a transducer formed in a rectangular plate shape and coupled to the waveguide 105 with an adhesive or the like. 104, and is inserted through an opening 102a formed at the bottom of the processing bath 102 in a state where the waveguide 105 side is in contact with the liquid. A flange portion 105 a is formed on the entire waveguide 105, and a packing 106 is interposed between the flange portion 105 a and the bottom portion of the processing tank 102, so that the waveguide body 105 is closely fixed to the bottom portion of the processing tank 102. Has been. The packing 106 functions as a liquid-tight and vibration-absorbing member.
[0007]
The vibrator 104 is composed of a PZT (piezoelectric: piezoelectric) element or the like. When a voltage having a predetermined drive frequency is applied by the oscillator 107 (see FIG. 5), ultrasonic vibration of this frequency is generated. The drive frequency is set extremely high, for example, 1 MHz. The ultrasonic vibration generating unit 103 including the vibrator 104 and the waveguide 105 and the oscillator 107 constitute an ultrasonic excitation device.
[0008]
The waveguide 105 is made of, for example, duralumin, and has a thickness H, that is, a dimension in the traveling direction of the ultrasonic vibration generated from the vibrator 104, which is an approximate integer of a half wavelength (λ / 2) of the ultrasonic vibration. Double, ideally just an integral multiple, and the resonance length. The waveguide body 105 resonates with the ultrasonic vibration generated by the vibrator 104, introduces ultrasonic vibration into the pure water 101 and excites it, and is immersed in the pure water 101. An object such as a silicon wafer (not shown) is cleaned.
[0009]
Here, the half wavelength (λ / 2) is calculated as follows.
λ / 2 = C / 2f
However,
λ: one wavelength C: sound speed of duralumin = 5.15 × 10 ⁵ cm
f: Frequency = 10 ⁶ Hz
Therefore, λ / 2 = 2.6 mm.
[0010]
In the conventional waveguide 105, the thickness H is set to 53 mm. That is, it is about 20 times the half wavelength λ / 2 (about 2.6 mm), and the thickness H is set large. Therefore, the waveguide 105 has a relatively large acoustic impedance, the pure water 101 existing as an external load above the waveguide 105 is insufficient for some reason, and the liquid level 101a is not guided. Even when the wave body 105 is lowered below the upper surface of the wave body 105, the acoustic impedance of the entire device is lowered, the vibration of the vibrator 104 is increased, the effective output is increased, and the effective output is increased to generate heat. Can be suppressed. Specifically, the acoustic impedance of the waveguide 105 is expressed by the following formula: Rma ₁ <Rma ₂ <Rma ₃ (1)
However,
Rma ₁ : acoustic impedance of the vibrator 104 Rma ₂ : acoustic impedance of the waveguide 105 Rma ₃ : set in a state satisfying the acoustic impedance of the pure water 101.
[0011]
The effect of suppressing the increase in effective output is apparent from the following equation.
^{Pa = Va 2 / Rma ··· (} 2)
Rma = Rma ₁ + Rma ₂ + Rma ₃ (3)
However,
Pa: Effective output Va: Applied voltage (constant)
Rma: acoustic impedance of the entire cleaning apparatus (including pure water 101)
That is, even if the pure water 101 decreases and the value of the acoustic impedance Rma ₃ becomes almost zero, the waveguide 105 has the acoustic impedance Rma ₂ of a required magnitude, so that the effective output Pa is large. It has a configuration that does not increase.
[0013]
The flange portion 105 a is formed with a pair of through holes 105 b along the longitudinal direction of the waveguide 105 as means for cooling the waveguide 105. A nipple 108a is screwed into one end of the through hole 105b, and a nipple 108b is screwed into the other end.
[0014]
Then, for example, pure water is supplied as a cooling fluid into the through hole 105b through the tube 109a connected to the nipple 108a, and the pure water as a cooling fluid is supplied through the tube 109b connected to the nipple 108b. It is configured to discharge.
[0015]
[Problems to be solved by the invention]
The conventional ultrasonic cleaning apparatus 110 has the following advantages.
[0016]
(1) The thickness H of the waveguide 105 is set large, and the waveguide 105 has a relatively large acoustic impedance. Therefore, even when the pure water 101 existing as an external load above the waveguide 105 is insufficient for some reason, and the liquid level 101a is lowered below the upper surface of the waveguide 105, the empty water is blown away. The state, that is, the acoustic impedance of the apparatus as a whole decreases and the vibration of the vibrator 104 increases, and the effective output increases to suppress heat generation. That is, the adhesive that fixes the vibrator 104 to the waveguide 105 can be prevented from degrading and peeling, and the vibrator 104 itself can be prevented from being cracked by heat. Yes.
[0017]
(2) As the cooling means for the waveguide body 105, a pair of through holes 105b are formed in the flange portion 105a, and a structure for supplying a cooling fluid such as pure water is provided. Since heat that adversely affects the heat can be removed as much as possible, the pair of through-holes 105b are provided in the flange portion 105a formed so as to protrude from the waveguide 105. The configuration is such that the ultrasonic vibration conducted by the waveguide 105 is not adversely affected such as attenuation.
[0018]
(3) Maintenance is extremely easy because there is no need to provide an interlocking facility consisting of a sensor or the like in order to prevent emptying.
[0019]
However, in the conventional ultrasonic cleaning apparatus 110, since the waveguide 105 constituting the ultrasonic excitation apparatus is made of duralumin as a material, for example, ozone gas-added pure water, hydrofluoric acid, or the like is used as a cleaning fluid. When a chemical solution such as an aqueous solution, an acidic aqueous solution, or an alkaline aqueous solution is used, there is a problem in that the portion of the waveguide 105 that contacts the cleaning fluid is eroded.
[0020]
Further, if the waveguide 105 is made of, for example, stainless steel, the corrosion resistance of the waveguide 105 can be improved. However, since stainless steel has a high density (ρ), it is resistant to ultrasonic vibration. It is a material with a relatively large loss. That is, there is a problem that the ultrasonic vibration generated from the vibrator 104 is wasted by being converted into thermal energy by the waveguide 105 and is not sufficiently transmitted to the cleaning fluid.
[0021]
The present invention has been made in view of the above points, and even when the cleaning fluid is reduced, an increase in effective output can be reliably suppressed, and an adverse effect such as attenuation can be exerted on the transmitted ultrasonic vibration. An object of the present invention is to provide an ultrasonic cleaning apparatus that can handle various types of cleaning fluid without giving it.
[0022]
[Means for Solving the Problems]
The ultrasonic cleaning apparatus of the present invention is an ultrasonic cleaning apparatus including a transport unit that transports an object to be cleaned, a liquid supply unit that supplies a cleaning fluid, and an ultrasonic excitation device that excites the cleaning fluid. The ultrasonic excitation device includes a vibrator that generates ultrasonic vibration of 200 KHz or more, and a waveguide that is coupled to the vibrator and guides the ultrasonic vibration to a cleaning fluid. The wave body is closely fixed to a flange portion formed so as to protrude over the entire circumference at a substantially central portion in the traveling direction of the ultrasonic vibration generated from the vibrator, and a surface side facing the surface having the vibrator. A wetted part vibrating body, and a gap is provided between the ultrasonic vibration oscillation surface of the wetted part vibrator and the surface of the object to be cleaned, and the liquid supply means is provided in the gap. the cleaning fluid is supplied, the liquid-contact portion vibrator, versus the cleaning fluid That has corrosion resistance, it covered the peripheral surface and a lower surface of the cleaning fluid and wetted the waveguide, and the material sound of the ultrasonic vibration dimensions the wetted vibrator in the direction of travel of It has a magnitude that is an integral multiple of a half wavelength of the ultrasonic vibration based on velocity.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the accompanying drawings.
[0031]
First, the ultrasonic cleaning apparatus of the present invention will be described with reference to FIGS.
[0032]
FIG. 1 is a perspective view showing an ultrasonic cleaning apparatus of the present invention, and FIG. 2 is a side view of the ultrasonic cleaning apparatus shown in FIG. 3 is a perspective view including a partial cross section showing the ultrasonic excitation device provided in the ultrasonic cleaning device shown in FIGS. 1 and 2, and FIG. 4 is a cross-sectional view of the ultrasonic excitation device taken along line AA in FIG. It is a cross-sectional arrow view.
[0033]
As shown in FIG. 1, an ultrasonic cleaning apparatus 10a includes an ultrasonic excitation apparatus 1, a transfer apparatus 2 as a transfer means for transferring a substrate 6 as an object to be cleaned such as a semiconductor wafer or a glass substrate, and a cleaning apparatus. And a liquid supply device 3 as liquid supply means for supplying the working fluid 15.
[0034]
First, the ultrasonic excitation device 1 provided in the ultrasonic cleaning device 10a will be described.
[0035]
As shown in FIG. 2 to FIG. 4, the ultrasonic excitation device 1 is formed in a substantially rectangular parallelepiped waveguide 9 and a rectangular plate, and has an adhesive or the like on the waveguide 9 on one side. A surface having the vibrator 7 which is the upper surface of the waveguide body 9, and an oscillator (not shown) that applies a voltage of a predetermined driving frequency to the vibrator 7. The wetted part vibrating body 12 is provided on the surface facing the surface, that is, on the lower surface side. And it is the structure which uses the oscillation surface 12a of the said liquid-contact part vibration body 12 below.
[0036]
The vibrator 7 includes a PZT (piezoelectric) element 16, and electrode plates 17 and 18 attached to the entire upper and lower surfaces of the PZT element 16, and the PZT element 16 and the upper side One of the corners of the electrode plate 17 is cut off. In the cut portion, the lower electrode plate 18 is folded back on the upper side, that is, on the same plane as the electrode plate 17 with an arc-shaped gap 20 between the electrode plate 17 and the electrode portion 18a. It has become.
[0037]
The length and width of the vibrator 7 are substantially equal to the length L and width W of the waveguide 9, and the thickness t is set to about 2 mm. The oscillator 7 (not shown) is driven by a predetermined amount. Either one of the two power transmission wires 22 a and the power transmission wire 22 b for applying a voltage of frequency is connected to a predetermined position of the electrode plate 17 and the electrode portion 18 a of the electrode plate 18.
[0038]
The vibrator 7 generates ultrasonic vibration of this frequency when a voltage having a predetermined driving frequency is applied by the oscillator (not shown). The driving frequency is set to an extremely high value of 200 KHz or higher, and is 1 MHz in this embodiment.
[0039]
The waveguide 9 resonates with the ultrasonic vibration generated by the vibrator 7 and functions as a member that transmits the ultrasonic vibration to the cleaning fluid 15 supplied by the liquid supply device 3. In this embodiment, the waveguide body 9 only transmits the ultrasonic vibration to the cleaning fluid 15 together with the liquid contact part vibration body 12, and does not have an action of mechanically amplifying. However, the amplification function may be provided by appropriately changing the shape and the like.
[0040]
The waveguide 9 is made of duralumin or aluminum, and protrudes over the entire circumference in the thickness direction, that is, the substantially central portion in the traveling direction of the ultrasonic vibration generated from the vibrator 7. It has the flange part 9a formed in the state to do. The waveguide 9 in this embodiment uses duralumin as a more preferable example. As shown in FIGS. 2 to 4, the waveguide 9 has a thickness H, that is, in the traveling direction of ultrasonic vibration generated from the vibrator 7, similarly to the conventional waveguide 105. The dimensions are set to be approximately an integral multiple of the half-wavelength (λ / 2) of the ultrasonic vibration calculated based on the material of the waveguide 9, in this case, the sound velocity of duralumin, ideally just an integral multiple. The resonance length has been reached.
[0041]
The thickness H is 53 mm in this embodiment as well as the conventional waveguide 105, and is set to about 20 times the half wavelength λ / 2 (about 2.6 mm). That is, by setting the thickness H large, the waveguide 9 has a relatively large acoustic impedance. In addition, the acoustic impedance of the waveguide 9 is set to a state that specifically satisfies the equation (1), similarly to the conventional waveguide 105.
[0042]
The value of the thickness H is arbitrarily determined according to the relationship with the acoustic impedance of the cleaning fluid 15 as an external load existing below the waveguide 9 and the magnitude of ultrasonic energy to be transmitted. It can be changed. By the way, conventionally, in a high frequency band as in this embodiment, waste of ultrasonic energy, that is, a large amount of heat is generated, and for example, it is commonly recognized that the thickness is limited to 2 to 3 times the half wavelength. It had been.
[0043]
In this embodiment, the waveguide 9 is formed using duralumin as a material. Duralumin has a density (ρ) of about 2.8 g / cm ^3, which is about 1 / compared to iron or stainless steel. It is three. That is, it is a material with very little loss against high-frequency ultrasonic vibrations, and is suitable as a material for the waveguide 9 in which the thickness H is set large. However, it can be used as a waveguide and can be used as long as it has a density equivalent to or lower than that of duralumin. For example, aluminum, aluminum alloy, or the like may be used. .
[0044]
Further, as shown in FIGS. 2 to 4, the dimension of the waveguide 9 in a direction perpendicular to the traveling direction of ultrasonic vibration generated from the vibrator 7 (the direction of the thickness H), that is, In this embodiment, the length L and the width W are set to 136 mm and 40 mm, respectively, and are about 52 times and about 15 times the half wavelength λ / 2 (about 2.6 mm), respectively. The length L and the width W are variable according to the size of the object to be cleaned.
[0045]
That is, assuming that the length L and the width W use a relatively low frequency band, such as about 20 KHz, for example, as the driving frequency of the vibrator 7, the waveguide 9 is Poisson. In order to suppress lateral vibration due to the influence of the ratio, it is necessary to set the size to λ / 3 or less. In addition, when it is desired to set the length L and the width W large, slits are formed at a pitch of λ / 3 or less, and waveguides having a small size of λ / 3 or less affect each other. It is necessary to take a form that is combined in a state without any. This is because vibration energy is prevented from being consumed in the waveguide itself due to the occurrence of lateral vibration, and clean longitudinal vibration without lateral vibration is imparted to the cleaning fluid 15.
[0046]
On the other hand, it has been confirmed from an experiment by the applicant of the present invention that there is no adverse effect of the Poisson's ratio, that is, no occurrence of lateral vibration at an extremely high frequency of 200 KHz or higher, for example, a driving frequency of 1 MHz set in this embodiment. The length L and the width W of the waveguide 9 can theoretically be increased without limitation. Therefore, the waveguide 9 does not need to form a slit, and the length L and the width W can be arbitrarily set to be λ / 3 or more.
[0047]
Similarly to the conventional waveguide body 105, the flange portion 9a of the waveguide body 9 has a pair of members along the longitudinal direction of the waveguide body 9 as means for cooling the waveguide body 9. A through hole 9b is formed. A nipple 28a is screwed into one end of the through hole 9b, and a nipple 28b is screwed into the other end.
[0048]
Two tubes 30a branched from the supply-side hose 34a through the socket 33a are connected to the nipple 28a, respectively. Through the hose 34a and the tube 30a, the through hole 9b serves as a cooling fluid. For example, pure water is supplied. On the other hand, two tubes 30b are connected to the nipple 28b, respectively, and the pure water as a cooling fluid is discharged together by a socket 33b in a hose 34b on the discharge side. .
[0049]
The cooling means composed of the through-holes 9b and the like is provided to heat the waveguide body 7 to a certain extent although it does not become high heat due to the self-resonance of the waveguide body 9, Heat that has an adverse effect can be removed with high efficiency.
[0050]
Next, the liquid contact part vibrating body 12 provided in the ultrasonic excitation device 1 will be described.
[0051]
The wetted part vibrating body 12 is made of a material having corrosion resistance to the cleaning fluid 15, in this case, stainless steel, and is formed in a substantially rectangular parallelepiped box shape corresponding to the waveguide body 9. The waveguide 9 is tightly fixed to the peripheral surface and the lower surface of the waveguide 9 with an epoxy adhesive or the like. The liquid contact part vibrating body 12 covers only a part of the waveguide body 9 that comes into contact with the cleaning fluid 15, and in this embodiment, a part (height) below the flange part 9a. H ₁ ) Covers the whole.
[0052]
In this embodiment, the thickness d of the wetted part vibrating body 12 in the traveling direction of ultrasonic vibration generated from the vibrator 7 (the direction of the thickness H) is set to about 3 mm. The thickness d is an integral multiple of the half wavelength (λ / 2) of the ultrasonic vibration calculated based on the sound velocity of the material of the wetted part vibrating body 12, and has a resonance length.
[0053]
Here, the half wavelength (λ / 2) of the liquid contact part vibrating body 12 is calculated as follows.
λ / 2 = C / 2f
However,
λ: one wavelength C: sound velocity of stainless steel = 5.5 × 10 ⁵ cm
f: Frequency = 10 ⁶ Hz
Therefore, λ / 2 = 2.8 mm.
[0054]
Further, in this case, the wetted part vibrating body 12 has a direction (length) perpendicular to the traveling direction (the direction of the thickness H) of the ultrasonic vibration generated from the vibrator 7 of the waveguide 9. The thickness d in the L direction and the width w direction is also about 3 mm, and the whole is a thin plate having a thickness approximately equal to the half wavelength (λ / 2). Therefore, the wetted part vibrating body 12 efficiently vibrates the ultrasonic vibration generated from the vibrator 7 together with the waveguide 9, and the ultrasonic vibration is applied to the cleaning fluid 15 from the oscillation surface 12a. In addition to being able to transmit, the ultrasonic vibration is not adversely affected such as attenuation.
[0055]
In addition, the wetted part vibrating body 12 can be used by appropriately selecting various materials having corrosion resistance to the cleaning fluid 15 to be used. As a material of the liquid contact part vibrating body 12, tantalum, titanium, quartz, sapphire, ceramics, etc. can be used in addition to stainless steel. That is, since the liquid contact part vibrating body 12 is configured to cover only a narrow range of the waveguide body 9 that is in contact with the cleaning fluid 15, for example, an expensive material such as sapphire is used. It is easy to use a material, and even a material that is difficult to be plastically processed, such as ceramics, can be used by easily processing a block-shaped material by cutting or the like.
[0056]
Next, the said conveying apparatus 2 with which the ultrasonic cleaning apparatus 10a of this invention is provided is demonstrated.
[0057]
The transfer device 2 as a transfer means for the object to be cleaned includes a plurality of rollers 2a arranged at equal intervals and a drive means (not shown) for driving the rollers 2a. And the said board | substrate 6 as a to-be-cleaned object is mounted on the said some roller 2a, for example, It has the structure which conveys the said board | substrate 6 at the predetermined speed in the arrow X direction.
[0058]
Next, the said liquid supply apparatus 3 with which the ultrasonic cleaning apparatus 10a of this invention is provided is demonstrated.
[0059]
As shown in FIG. 1, a liquid supply device 3 as a liquid supply means for the cleaning fluid 15 includes a liquid supply member 3a for supplying the cleaning fluid 15 from the traveling direction side of the substrate 6 as an object to be cleaned. And a suction member 3b for sucking the cleaning fluid 15 by the action of a pump (not shown).
[0060]
In the present embodiment, the cleaning fluid 15 sucked by the suction member 3b is cleaned by a filter (not shown) and returned to the liquid supply member 3a. That is, the amount of the cleaning fluid 15 used can be greatly reduced. Although the effect of suppressing the usage amount of the cleaning fluid 15 is reduced, the cleaning fluid 15 sucked by the suction member 3b may be discarded as it is, and in addition to the liquid supply member 3a The liquid may also be supplied from the suction member 3b side.
[0061]
Next, the operation of the ultrasonic cleaning apparatus 10a of the present invention will be described.
[0062]
As shown in FIGS. 1 and 2, first, when a voltage having a predetermined drive frequency is applied to the vibrator 7 from the oscillator (not shown), the vibrator 7 is excited, and an ultrasonic wave having this frequency is applied. Generates vibration. The generated ultrasonic vibration is transmitted to the cleaning fluid 15 supplied as an external load below the liquid contact part vibration body 12 via the waveguide body 9 and the liquid contact part vibration body 12. It is the composition which becomes.
[0063]
The ultrasonic cleaning apparatus 10a according to the present invention can be used as an object to be cleaned such as a glass substrate unless the cleaning fluid 15 as an external load is supplied to the lower part of the oscillation surface 12a of the wetted part vibrating body 12. No ultrasonic vibration is transmitted to the substrate 6.
[0064]
Therefore, as shown particularly in FIG. 2, the clearance e between the surface 6a of the substrate 6 and the oscillation surface 12a, that is, the separation distance is set to about 3 to 5 mm, and the substrate 6 serves as the transport means. The roller 2a of the apparatus 2 passes in the conveying direction indicated by an arrow X (shown in FIG. 1), and the cleaning fluid 15 is supplied from the liquid supply member 3a into the gap e in the direction indicated by the arrow Xa (shown in FIG. 1). To supply. At this time, a liquid film of the cleaning fluid 15 is formed between the surface 6a of the substrate 6 and the oscillation surface 12a (gap e ) by the action of surface tension, and the vibrator 7 is interposed through the liquid film. Is transmitted to the substrate 6. Therefore, the ultrasonic cleaning apparatus 10a can clean the substrate 6 by the action of the liquid film of the cleaning fluid 15.
[0065]
At this time, the ultrasonic vibration generated from the vibrator 7 is transmitted in a direction perpendicular to the oscillation surface 12a of the liquid contact part vibrating body 12, and the oscillation surface 12a having the same width as the vibrator 7 Since the substrate 6 as the object to be cleaned is uniformly irradiated while vibrating uniformly over the entire surface, the cleaning effect on the surface 6a of the substrate 6 is high.
[0066]
In addition, the waveguide body 9 includes the liquid contact portion vibrating body 12 having corrosion resistance to the cleaning fluid 15 at a portion in contact with the cleaning fluid 15. Various chemicals such as ozone gas-added pure water, hydrofluoric acid aqueous solution, acidic aqueous solution, and alkaline aqueous solution can be used.
[0067]
The ultrasonic cleaning device 10a has the following operational effects, for example.
[0068]
That is,
(1) Since the waveguide 9 has the wetted part vibrating body 12 having corrosion resistance to the cleaning fluid 15 at the wetted part with the cleaning fluid 15, Various chemicals such as ozone gas-added pure water, hydrofluoric acid aqueous solution, acidic and alkaline aqueous solution can be used as the cleaning fluid 15 according to the material and the like. The wetted part vibrating body 12 is formed into a thin plate as a whole, and the thickness d is a half wavelength (λ / w) of the ultrasonic vibration calculated based on the sound speed of the material of the wetted part vibrator 12. It is an integral multiple of 2) and is the resonance length. Therefore, the wetted part vibrating body 12 efficiently vibrates the ultrasonic vibration generated from the vibrator 7 together with the waveguide 9, and does not adversely affect the ultrasonic vibration such as attenuation.
[0069]
(2) The oscillation surface 12a having the same width as the vibrator 7 vibrates uniformly over the entire surface, and the ultrasonic vibration from the vibrator 7 is evenly applied to the substrate 6 as an object to be cleaned. Therefore, the cleaning effect on the substrate 6 is high.
[0070]
(3) Since the cleaning fluid 15 having an amount of liquid sufficient to form a surface tension needs to exist between the oscillation surface 12a and the surface 6a of the substrate 6 as an object to be cleaned, the cleaning The usage amount of the working fluid 15 can be greatly reduced.
[0071]
(4) The thickness H of the waveguide 9 is set to be large, and the waveguide 9 has a relatively large acoustic impedance. Therefore, even if the amount of the cleaning fluid 15 existing as an external load below the waveguide 9 is insufficient, the acoustic impedance of the vibrator 7 is reduced because the acoustic impedance of the entire device is reduced. As the vibration increases, the effective output increases to suppress heat generation. That is, the adhesive that fixes the vibrator 7 to the waveguide 9 can be prevented from degrading and peeling, and the vibrator 7 itself can be prevented from cracking due to heat. Yes.
[0072]
(5) A pair of through holes 9b are formed in the flange portion 9a as a cooling means for the waveguide body 9, and a structure for supplying a cooling fluid such as pure water is provided. As much as possible, heat that adversely affects the heat can be removed.
[0073]
(6) Maintenance is extremely easy because there is no need to provide an interlocking facility consisting of sensors or the like in order to prevent flying.
[0074]
In the ultrasonic cleaning device 10a of the present embodiment, the ultrasonic excitation device 1 is configured to be used with the oscillation surface 12a side of the wetted part vibrating body 12 facing down. For example, the ultrasonic excitation device 1 may be applied to a cleaning tank type ultrasonic cleaning device such as the conventional ultrasonic cleaning device 110, and the oscillation surface 12a may be used on the upper side.
[0075]
In the present embodiment, the waveguide 9 is formed in a substantially rectangular parallelepiped shape, but various shapes such as a disk shape can be employed according to the shape of the space to be installed.
[0076]
【The invention's effect】
As described above, according to the ultrasonic cleaning apparatus of the present invention, it is possible to reliably suppress an increase in effective output even when the cleaning fluid decreases, and to adversely affect the transmitted ultrasonic vibration such as attenuation. Can be applied to various cleaning fluids according to the purpose of cleaning and the material of the object to be cleaned.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an ultrasonic cleaning apparatus of the present invention.
FIG. 2 is a side view of the ultrasonic cleaning apparatus shown in FIG.
3 is a perspective view including a partial cross-section showing an ultrasonic excitation device provided in the ultrasonic cleaning device shown in FIGS. 1 and 2. FIG.
4 is a cross-sectional view taken along the line AA in FIG. 3 of the ultrasonic excitation device.
FIG. 5 is a side view including a partial cross section showing a conventional ultrasonic cleaning apparatus.
FIG. 6 is a perspective view including a partial cross section showing a conventional ultrasonic vibration generator provided in a conventional ultrasonic cleaning apparatus.

Claims (1)

An ultrasonic cleaning apparatus comprising a transport means for transporting an object to be cleaned, a liquid supply means for supplying a cleaning fluid, and an ultrasonic excitation device for exciting the cleaning fluid,
The ultrasonic excitation device includes a vibrator that generates an ultrasonic vibration of 200 KHz or more, and a waveguide that is coupled to the vibrator and guides the ultrasonic vibration to a cleaning fluid.
The waveguide closely adheres to a flange portion formed so as to protrude over the entire circumference at a substantially central portion in a traveling direction of ultrasonic vibration generated from the vibrator, and a surface facing the surface having the vibrator. It has a fixed wetted part vibrating body,
There is a gap between the ultrasonic vibration oscillation surface of the wetted part vibrating body and the surface of the object to be cleaned, the liquid supply means supplies the cleaning fluid into the gap,
The liquid contact part vibrating body has corrosion resistance to the cleaning fluid, covers a peripheral surface and a lower surface of the waveguide that are in contact with the cleaning fluid, and
The ultrasonic cleaning apparatus, wherein a dimension in a traveling direction of the ultrasonic vibration has a size that is an integral multiple of a half wavelength of the ultrasonic vibration based on a sound speed of a material of the liquid contact part vibrating body.

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