JP2919451B1 - Floating and transporting device in liquid and method thereof - Google Patents

Abstract

The present invention provides an apparatus and a method for floating a liquid in a liquid, which floats a non-conveyed object in a liquid and conveys the liquid in a non-contact manner and has a cleaning function. SOLUTION: A transfer tank 10A accommodating a liquid 16 and ultrasonic excitation means 20 for emitting ultrasonic waves to the liquid 16 in the transfer tank 10A are provided. The apparatus is characterized in that the transported object 5 is levitated on 16 and travels.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating apparatus and a method for floating a liquid to be conveyed in a non-contact manner.

[0002]

2. Description of the Related Art In the field of semiconductor devices, miniaturization of semiconductor substrates,
Multi-layered wiring has been developed along with higher density such as reduction in chip area. However, if this is simply multi-layered, the unevenness becomes larger in the upper layer pattern, and there is a limit to the multi-layering in the current photolithography process alone due to a decrease in the focus margin.

Therefore, as a technique for flattening an interlayer insulating film of a multilayer wiring of a semiconductor substrate, chemical mechanical polishing (hereinafter, referred to as C
MP). Since an abrasive called a slurry is used in the CMP, it is necessary to completely remove the slurry after polishing and to transport the slurry to the next step without contamination from outside. In addition, this slurry becomes a powder when dried and adheres, and it is difficult to remove the slurry from the surface of the semiconductor substrate.

[0004] That is, in the case of CMP, the semiconductor substrate after polishing has 1) a large amount of particles adhered thereto.

2) Since an alkali-based slurry is used as an abrasive, the slurry is contaminated with an alkali metal or the like.

[0006] 3) The abrasive which has not been removed is fixed when dried and cannot be removed.

For this reason, it is preferable that the polished semiconductor substrate be immediately moved into the liquid and stored, and also transported in the liquid.

As described above, the surface of a flat substrate object (silicon wafer, liquid crystal glass, etc.) must be completely controlled and kept clean during the manufacturing process. Transport and storage of objects will become increasingly important in the future.

Conventionally, as a method of transporting a semiconductor substrate without drying, a semiconductor substrate is transported by using a submerged transport device having a transport drive unit (roller, belt, chain, etc.) installed in the liquid. A common method is to place the unit on the drive unit and transport it in liquid without touching the outside air.

[0010]

However, in such a conventional submerged transport apparatus, since a transport drive section exists in the liquid, contamination of the semiconductor substrate due to dust from the drive section occurs. There was a problem that it was easy to do.

Further, since the above-described submerged transfer apparatus does not have a mechanism for removing particles adhered to the semiconductor substrate, it is necessary to provide a cleaning mechanism separately from the transfer apparatus.

For this reason, there has been a demand for a submerged transfer device capable of transporting an object to be transported such as a semiconductor substrate in a non-contact manner and having a cleaning function.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and provides an apparatus and a method for floating in a liquid having a function of floating, wherein the object to be transported is levitated in liquid and transported in a non-contact manner. With the goal.

[0014]

According to the present invention, there is provided a submerged levitation transfer device having a slope bottom surface inclined in one direction with respect to a horizontal plane.
And a transfer tank containing a liquid, mounted on the slope bottom surface.
Radiates ultrasonic waves with a frequency of 500 KHz or more to the liquid
Ultrasonic excitation means including a thin plate-shaped vibrator
The acoustic stream of the ultrasonic waves radiated from the ultrasonic excitation means is
With the conveyed object floating in the liquid or on the liquid surface
To generate a propulsion force reflected on the lower surface of the transferred object.
Travels the transferred object in the direction of lower height of the slope bottom surface
And cleaning the transferred object by the ultrasonic waves.
Is what you do.

[0015] Further, the slope bottom surface is formed with respect to the horizontal plane.
At an angle of 2 to 5 degrees .

[0016] The method of the submerged buoyant conveying invention, horizontal
Transfer tank with a sloped bottom that slopes in one direction relative to the surface
A thin plate-shaped vibration attached to the bottom of the gradient is applied to the stored liquid.
500 kHz or more by ultrasonic excitation
The ultrasonic wave of the wave number is radiated and radiated from the ultrasonic excitation means.
The acoustic wave of the ultrasonic wave moves the transferred object in the liquid or
Float on the liquid surface and at the lower surface of the transferred object
The propulsion is reflected to generate the propulsion force, and the transferred object
Run in the direction of low surface height, and
Thus, the object to be conveyed is cleaned .

Further, the liquid in the flotation conveying apparatus of the present invention, the liquid
And a transfer tank for storing the liquid in the transfer tank substantially horizontally.
A plate-shaped vibrating body that can be flexibly vibrated by providing the vibrating body;
Exciting the vibrator provided at one end to bend and vibrate
Ultrasonic excitation means, provided at the other end of the vibrating body,
Ultrasonic energy generated by the vibrator is converted into electrical energy
Energy conversion means for converting the energy,
Means generate ultrasonic vibration with a frequency of 500 kHz or more
Vibrating, and transmitting the ultrasonic vibration to the vibrating body
Horn and radiation pressure of ultrasonic waves generated by the vibrating body
The object to be conveyed in the liquid above the vibrating body or on the liquid surface
Levitates the body and flexes the vibrating body.
The transported object is caused to travel by the traveling wave generated by
First, the object to be conveyed is cleaned by the ultrasonic waves .

Further, the method of floating and transporting in a liquid according to the present invention comprises the steps of:
Is provided almost horizontally in the liquid in the transfer tank containing
A vibrating plate-like vibrator is provided at one end of the vibrator.
To generate ultrasonic vibration with a frequency of 500 kHz or more
A transducer for transmitting the ultrasonic vibration to the vibrating body.
The vibration caused by the ultrasonic vibration
The energy conversion means provided at the other end of the vibrating body.
The ultrasonic energy generated by the vibrating body is
And the radiation pressure of the ultrasonic waves generated by the vibrating body.
The object to be conveyed in the liquid above the vibrating body or on the liquid surface
Levitates the body and flexes the vibrating body.
The transported object is caused to travel by the traveling wave generated by
First, the object to be conveyed is cleaned by the ultrasonic waves .

[0019]

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. This submerged levitation transfer apparatus 1A is an ultrasonic excitation including a transfer tank 10A having a sloped bottom surface 12 and a vibrator 24 mounted on the sloped bottom surface 12. And means 20.

The transfer tank 10A has a rectangular cross-sectional shape with an open upper part, is formed to extend long in the direction in which the transferred object 5 is transferred, and stores, for example, pure water as the liquid 16 for floating transfer. And a gradient bottom surface 1 inclined at an angle θ in the longitudinal direction with respect to the liquid surface 16a (horizontal surface).
2 is formed.

The ultrasonic excitation means 20 includes an oscillator 22 and a vibrator 24, and the vibrator 24 is fixed to the lower surface of the gradient bottom surface 12.

The vibrator 24 is formed so that a voltage of a predetermined frequency is applied by the oscillator 22 to generate ultrasonic vibration of the frequency. This ultrasonic vibration is transmitted to the liquid 16 through the gradient bottom surface 12, specifically, about 5
Ultrasonic energy of 00 KHz or more, for example, 1 MHz, 5 w / cm ² is radiated into the liquid 16.

Next, the operation of the submerged levitation and transport device configured as described above will be described.

First, the levitation operation of the transferred object 5 will be described with reference to FIG. 2, the flotation tank 10C has a bottom surface 14 parallel to the liquid surface 16a, and a vibrator 24 is mounted on the bottom surface 14.

In this state, when a voltage of a predetermined frequency is applied to the vibrator 24, ultrasonic vibration of that frequency is generated, and the ultrasonic wave excites the liquid 16 via the bottom surface 14, and the liquid 1
6 is radiated toward the liquid surface 16a.

Thereafter, the transported object 5 arrives horizontally on the liquid surface 16a and floats on the liquid surface 16a. At this time,
The lower surface of the transported object 5 has an ultrasonic wave 25 a from the vibrator 24.
Receive radiation. The transported object 5 is in a floating state on the liquid surface 16a or in the liquid 16 due to the ratio of the weight of the object itself to the floating amount and the radiation pressure of the ultrasonic waves 25a emitted from the vibrator 24. It floats in a horizontal state at a required floating distance e from 14.

When the transported object 5 is a heavy object, it may be placed on the bottom surface 14 before the vibrator 24 starts to vibrate. In this case, for example, 1 MH
When ultrasonic energy of 5 w / cm ² is radiated into the liquid 16, a 6-inch silicon wafer is 0.1 sec.
It begins to ascend within and continues to levitate as long as the ultrasound is emitted.

Here, it is assumed that the transported object 5 is a relatively flat and relatively lightweight one, for example, a thin sheet made of synthetic resin or metal. These objects are levitated as test specimens by the apparatus shown in FIG. 2, but those which are difficult to levitate by themselves are carried on a flat carrier similar to the above-mentioned transported object 5. Can be levitated. Examples of the transported object 5 requiring such a flat carrier include an object having a shape close to a sphere, an object having an uneven shape, a powder or liquid contained in a container, and the like.

Next, the operation of the submerged levitation and conveying apparatus 1A including the above-described levitation of an object will be described.

The submerged levitation transporting apparatus 1A is obtained by adding a traveling means for traveling the levitated transported object 5 to the configuration of the levitation apparatus shown in FIG. As this traveling means, the transport tank 10A employs a configuration having a slope bottom surface 12 having an inclination angle θ with respect to the horizontal plane. In the experiment, the angle θ was set to 2 to 5 degrees.

As is apparent from FIG. 1, the slope bottom surface 12 is
It is formed so as to increase from the right side to the left side of the transfer tank 10A, and is, for example, in a non-parallel state with the horizontal transferred object 5 floating in the liquid 16.

When power is supplied to the vibrator 24, the ultrasonic waves from the vibrator 24 pass through the gradient bottom surface 12,
It is emitted upward into the liquid 16 at right angles to 2. The acoustic stream of the ultrasonic waves 25a in the liquid 16 is obliquely incident on the lower surface of the non-parallel transported object 5, rebounds, exerts a levitating action, and is further reflected obliquely to the lower right (FIG. 3). reference). The transported object 5 is accelerated by the propulsive force of the reflected wave 25b and travels in the direction of the two-dot chain line arrow A. In the present specification, the acoustic stream of the ultrasonic wave 25a is used as including a radiation pressure for levitating the transported object 5 and a traveling wave for traveling the transported object 5.

The upper, lower, and end surfaces of the object 5 to be transferred are directly irradiated with ultrasonic waves from the inclined bottom surface 12 during the transfer in the liquid 16 or reflected by the side surface in the transfer tank 10A. The irradiation of the refracted ultrasonic waves removes foreign substances such as slurry adhering to the surface of the transported object 5 and exerts a cleaning action.

Further, since there is no drive unit such as a roller and a chain in the transport tank 10A, contamination of the liquid 16 by these external elements can be prevented.

FIGS. 4 and 5 show a second embodiment of the present invention, which is characterized in that the traveling means for traveling the object to be transported 5 comprises a vibrating body, an ultrasonic excitation means and an energy conversion means. Have. In the following description, components that are the same as or equivalent to those in the first embodiment are given the same reference numerals, and descriptions thereof are omitted.

The levitation transfer device 1B according to the second embodiment.
Are a transfer tank 10B having a bottom surface 14 substantially parallel to the liquid surface 16a, a vibrating body 18 provided substantially horizontally in the transfer tank 10B, and an ultrasonic exciting means 20 provided at one end of the vibrating body 18. , An energy conversion means 30 provided at the other end of the vibrating body 18.

The transport tank 10B has a rectangular cross-sectional shape with an open top, is formed to extend in the transport direction, and has a bottom surface 14 substantially parallel to the liquid surface 16a of the stored liquid 16. I'm here.

The vibrating body 18 is formed of a rectangular duralumin plate, and is provided in the liquid 16 substantially parallel to the bottom surface 14 of the transfer tank 10B at a predetermined distance. In addition, as the material of the vibrating body 18, various materials such as stainless steel, which is carbon steel and its alloy steel, and a titanium alloy can be adopted.

In the present embodiment, the ultrasonic excitation means 20 comprises an oscillator 22, a vibrator 24, and a horn 26, and is installed on the right end side of the vibrator 18, as shown in FIG.

The vibrator 24 and the lower part of the horn 26 are located in a case 28, and the upper part of the horn 26 is
9, and protrudes into the transport tank 10B, and the tip is fastened to the vibrating body 18 by a fixing screw (not shown).

When a voltage of a predetermined frequency is applied to the electrode 24a of the vibrator 24 by the oscillator 22, an ultrasonic vibration of this frequency is generated, and the horn 26 is moved upward and downward in FIG. It is configured to vibrate in the direction and mechanically amplify the vibration and transmit it to the right end of the vibrating body 18.

The energy conversion means 30 has substantially the same configuration as that of the ultrasonic excitation means 20, and is installed on the left end side of the vibrating body 18. The energy conversion means 30 includes a vibrator 24 and a horn 26, and a circuit including a resistor R and a coil L is connected to an electrode 24a of the vibrator 24.
The tip of the horn 26 is fastened to the vibrating body 18 by a fixing screw.

The energy converting means 30 converts the ultrasonic energy generated by the vibrating body 18 excited by the ultrasonic exciting means 20 into electric energy again. Then, the electric energy passes through the RL circuit and is further converted into Joule heat and dissipated.

According to the submerged levitation and transport apparatus of the second embodiment, when the ultrasonic excitation means 20 and the energy conversion means 30 act simultaneously, the horn 2 of the ultrasonic excitation means 20
6, the vibrating body 18 is excited, the ultrasonic wave is emitted from the vibrating body 18, and the vibrating body 18 performs bending vibration as shown by a curve B, and the wave of the bending vibration advances toward the energy conversion means 30. It becomes a wave.

After the vibrating body 18 starts to vibrate in this manner, the transported object 5 is brought to the right end side of the transport tank 10B or floated on the liquid surface 16a in a horizontal state.

At this time, the conveyed object 5 floats on the liquid surface 16a or in the liquid 16 by the radiation pressure of the ultrasonic wave emitted from the vibrating body 18 in the same manner as described above for the floating action. Simultaneously with the levitating, the transported object 5 rides on the traveling wave and travels in the direction of the two-dot chain line arrow A. The cleaning action for removing foreign substances during the transfer of the transported object 5 and the cleanliness maintaining action by protection from external contamination are the same as in the first embodiment.

The present invention is not limited to the above description and examples, but can be modified in its embodiments. For example, one transfer tank 10A longer in the longitudinal direction
With two or more vibrators 24 connected in series, or one transfer tank 10B longer in the longitudinal direction.
Alternatively, two or more sets of the vibrating body 18, the ultrasonic excitation means 20, and the energy conversion means 20 may be provided in series. Thereby, the length of the transport path can be freely set. The cross-sectional shape of the transfer tank 10A (10B) is
The shape may be a polygon, a circle, or a mixture thereof.

[0050]

As described above, the floating device of the present invention is capable of floating the object to be transported in the liquid in the transport tank and transporting it without contact from outside without contact. it can.

Further, since the entire surface of the object to be transported is irradiated with ultrasonic waves for floating and transporting, the object to be transported can be cleaned while being transported. That is, the levitation transporting apparatus itself has an ultrasonic cleaning function, so that a special cleaning mechanism for the cleaning operation is not required, and the cleaning operation time can be reduced.

Further, unlike the conventional submerged transfer apparatus, since there is no transfer drive section in the liquid, contamination of the liquid in the transfer tank from external elements can be prevented, and the transfer apparatus can be simplified. With the configuration, downsizing and cost reduction can be achieved.

In addition, since the levitation and the transfer are performed by the radiation pressure of the ultrasonic waves converted from the electric energy, the safety of the work can be improved and the control of the apparatus can be easily performed. I have.

[Brief description of the drawings]

FIG. 1 is a front view including a partial cross section of a levitation transporting device according to a first embodiment of the present invention.

FIG. 2 is a levitation explanatory view showing a levitation action of a transferred object.

FIG. 3 is a partially enlarged view for explaining the operation of the submerged levitation transfer device shown in FIG. 1;

FIG. 4 is a front view including a partial cross section of a submerged levitation transfer device according to a second embodiment of the present invention.

FIG. 5 is a transverse sectional view taken along line CC of FIG. 4;

[Explanation of symbols]

 Reference Signs List 1A, 1B floating device in liquid 5 object to be transported 10A, 10B transfer tank 12 gradient bottom 16 liquid 16a liquid level 18 vibrating body 20 ultrasonic excitation means 24 vibrator 26 horn 30 energy conversion means

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yoshikazu Koike 3-16-12-409 Chuo-Rinkan, Yamato-shi, Kanagawa (56) References JP-A-59-82222 (JP, A) JP-A-7-187388 ( JP, A) JP-A-61-166429 (JP, A) JP-A-61-62722 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B65G 53/30 B06B 3/00 B65G 27/00 F03G 7/00

Claims (5)

(57) [Claims] 1. A slope bottom which is inclined in one direction with respect to a horizontal plane.
A transfer tank having a surface and containing a liquid; and 500 KHz or more for the liquid mounted on the slope bottom surface.
Including a thin plate-shaped vibrator that emits ultrasonic waves of different frequencies
Wave excitation means, the acoustic flow of ultrasonic waves emitted from the ultrasonic excitation means,
When the conveyed object is levitated in the liquid or on the liquid surface,
In addition, a propulsion force is generated by being reflected on the lower surface of the transferred object.
The object to be conveyed in the direction of lower height of the slope bottom.
Cleaning the object to be conveyed by the ultrasonic waves.
A floating device in a liquid characterized by cleaning. 2. The inclined bottom surface has a height of 2 with respect to the horizontal plane.
5. The method of claim 1, wherein the angle of inclination is between about 5 degrees and about 5 degrees.
2. The levitation transport device according to claim 1. 3. A slope bottom inclined in one direction with respect to a horizontal plane.
The liquid contained in the transfer tank having
5 by the ultrasonic excitation means including the attached thin plate vibrator.
Ultrasonic waves having a frequency of 00 KHz or more are radiated, and the acoustic flow of the ultrasonic waves radiated from the ultrasonic excitation means is:
When the conveyed object is levitated in the liquid or on the liquid surface,
In addition, a propulsion force is generated by being reflected on the lower surface of the transferred object.
The object to be conveyed in the direction of lower height of the slope bottom.
Cleaning the object to be conveyed by the ultrasonic waves.
Floating and transporting in liquid characterized by purifying . 4. A transfer tank for containing a liquid, and provided substantially horizontally in the liquid in the transfer tank and capable of flexural vibration.
A plate-shaped vibrating body, which is provided at one end of the vibrating body to excite and vibrate the vibrating body
An ultrasonic exciting means for vibrating only, and an ultrasonic wave provided at the other end of the vibrating body and generated by the vibrating body.
Energy that converts sound energy into electrical energy
Conversion means, and the ultrasonic excitation means has a frequency of 500 kHz or more.
A vibrator for generating ultrasonic vibration, and the ultrasonic vibration
A horn for transmitting to a moving body , wherein the vibrating body is driven by a radiation pressure of an ultrasonic wave generated by the vibrating body.
When an object to be transported is levitated in the liquid above or above the liquid level,
Both are traveling waves generated by bending vibration of the vibrating body.
Makes the conveyed object travel, and
Therefore , the levitation transfer device is characterized in that the transferred object is washed . 5. The method according to claim 5, wherein the liquid in the transfer tank containing the liquid contains substantially water.
The flat vibrating body, which is provided flat and can be flexibly vibrated, is
It is provided at one end of the moving body and has a frequency of 500 KHz or more.
A vibrator for generating ultrasonic vibration, and the ultrasonic vibration
And a horn transmitting to the vibrating body.
Excited to bend and vibrate, and energy conversion means provided at the other end of the vibrating body
The ultrasonic energy generated by the vibrator is converted into electric energy
The vibrating body is converted by the radiation pressure of the ultrasonic wave generated by the vibrating body.
When an object to be transported is levitated in the liquid above or above the liquid level,
Both are traveling waves generated by bending vibration of the vibrating body.
Makes the conveyed object travel, and
Therefore, the method of levitation transfer in liquid, comprising washing the object to be transferred .