JPH10157851A - Object-to-be-conveyed conveying method in floatation type conveying device and floatation type conveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a floatation type conveying device, by which uniform pressure film is formed between an object to be conveyed and a conveying member and stability in the floating condition of the object to be conveyed is stability so that the object to be conveyed can be conveyed without any deflection from a target route, at a low cost. SOLUTION: Conveying members 2a, 3a provided with multiple small diameter jetting ports 5 are arranged in a conveying path, and fluid serving as a conveying medium is jetted from the conveying members 2a, 3a so as to float and convey an object to be conveyed without any contact with the conveying path. The conveying members 2a, 3a are formed of porous material, and the vacuum conveying member 2a provided with a vacuum port 2 is arranged in the center of the conveying path while the pressurizing conveying members 3a provided with a pressurizing port 3 are arranged in the both end parts of the conveying path, so that the conveying medium flows from the both end parts to the center part, and the object to be conveyed is floated while being guided toward the center part of the conveying path so as to be conveyed in a required direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of transporting an object to be transported such as a semiconductor wafer (hereinafter referred to as "object to be transported") in a non-contact manner by ejecting a carrier medium from a small-diameter ejection port to float the medium. And a floating type transport device.

[0002]

2. Description of the Related Art Conventionally, as a method of transporting a body to be transported, a transport member having a large number of small-diameter injection ports is arranged in a transport path, and a gas or liquid fluid (hereinafter, referred to as a “liquid”) is provided from the injection ports.
A method is known in which a transport medium is ejected, and the transported body is transported without contacting the transport path.

[0003] However, the object floats due to the pressure film generated by the medium to be ejected from the object to be ejected from the small-diameter ejection port provided in the conveying member, but does not come into contact with the object (the contact resistance is zero). There is a problem that the trajectory deviates from the target trajectory due to the inclination of the transport path and the unevenness of the pressure film. For this reason, a guide rail or the like is provided to prevent the deviation phenomenon. However, since the semiconductor wafer involves a contact action with a hard substance which is least desired by the semiconductor wafer, an alternative transport method capable of preventing the deviation phenomenon is required.

[0004] A transfer method for preventing a deviation phenomenon without providing a guide rail or the like is disclosed in Japanese Patent Publication No. 140496/1994. This invention focuses on the unstable operation of the receiver due to the irregularity of the injection ports, and is based on the fact that the receiver exerts a desired action by an ordered and irregular configuration. This departure prevention method will be described with reference to FIG. As shown in FIG.
By making the opening distribution of the injection ports dense at both ends and making the center sparse, the lift by the transport medium is high at both ends and low at the center. As a result, the overall lift has a shape similar to a reverse parabola, so that the transmitted pair 10 at the center of the transport member 20 is stable, and the transmitted body 10 at the end (shown by a dotted line in the drawing). ) Is guided to the central part where the lift is small.

Alternatively, as shown in FIG. 6 (B), by setting the ejection direction of the carrier medium to be directed above the center line O of the carrier member 21, the object 10 is shifted to a position deviated from the center line O. In some cases, the transported object 1 is moved so that the center line O is located at the center position by the propulsive action in the biased injection direction.
0 is guided to the center. Further, even if the above two types of methods are combined, the object to be transmitted can be similarly guided to the center.

[0006]

However, according to the conveying method described in Japanese Patent Publication No. 40496/1992, the conveying medium ejected from the ultra-fine-diameter ejection openings opened on the surfaces of the conveying members 20 and 21 can be any ejection medium. It is necessary that the fuel be sprayed uniformly from the mouth and in the set spray direction. Therefore, in order to satisfy this condition, it is necessary to perforate the injection port on the surface of the conveying member with high precision, which makes the perforation processing difficult, and as a result, the conveying member becomes expensive. For this reason, there has been a problem that the transport device itself is expensive.

Further, the rigidity (stability) of the transported body in the floating state is low, so that the transported body is transported in a considerably unstable state, and may be deviated from the target trajectory under the influence of external airflow or vibration. Very likely to end up.

Accordingly, the present invention has been made to solve the above-mentioned problems, and a uniform pressure film is formed between an object to be transferred and a conveying member to increase the stability in a floating state. It is an object of the present invention to provide a transport method capable of transporting a transported object without deviating from the trajectory, and to provide a floating transport device that can be realized at low cost.

[0009]

According to the first aspect of the present invention, there is provided a transporting member having a plurality of small-diameter ejection ports in a transporting path, and a fluid is supplied from the transporting member. In the method of ejecting as a transport medium and transporting the transported body without contacting the transport path by floating the transported body, pressurizing ports are provided at both ends of the transport path, and the transported body is located at the center of the transport path. It is characterized in that it can be levitated while being guided and transported in a desired direction.

By providing the pressurizing ports at both ends of the transport path, a lift by the transport medium is generated only at both ends of the object to be transported, so that deviation from the target transport trajectory can be prevented.

According to the second aspect of the present invention, in order to solve the above-mentioned problem, a conveying member having a plurality of small-diameter ejection ports is provided on a conveying path, and a fluid is jetted from the conveying member as a conveying medium, and the conveying member is ejected. In the method in which the transfer member is lifted and transferred without contacting the transfer path, the transfer member is formed of a porous material, and pressurized ports are provided at both ends of the transfer path to transfer the transfer target to the transfer path. , While being guided to the central portion of the, and can be transported in a desired direction.

By providing pressurizing ports at both ends of the transfer path and using a porous material as a transfer member, a lift is generated only by the transfer medium at both ends of the object to be transferred,
Further, since the pressure film formed by the transport medium becomes uniform, the transported object is guided to the central portion of the transport path while maintaining a very stable state. Therefore, the transported object can be stably transported along the target trajectory.

According to a third aspect of the present invention, in order to solve the above-mentioned problems, a conveying member having a plurality of small-diameter ejection ports is provided on a conveying path, and a fluid is jetted from the conveying member as a conveying medium, and the conveying member is ejected. In the method in which the transport body is lifted and transported without contacting the transport path, a vacuum port is provided at a central portion of the transport path, and pressurizing ports are provided at both ends of the transport path, and the transport medium transports the transport medium. The present invention is characterized in that the object is caused to flow from both ends of the path to the center, and that the object to be transported is floated while being guided to the center of the conveying path, and is conveyed in a desired direction.

By providing a vacuum port at the center of the transfer path, the transfer object is sucked, so that the rigidity (stability) of the transfer object in the floating state is higher than that of the conventional transfer method. Was. As a result, instability during transport of the transported object is eliminated. Furthermore, by providing pressurized ports at both ends of the transport path, the flow of the transport medium is created in the direction from both ends of the transport path to the center. The body is guided to the center of the transport path. That is, it is possible to prevent a deviation from the target trajectory.

According to a fourth aspect of the present invention, in order to solve the above-mentioned problems, a conveying member having a plurality of small-diameter ejection ports is provided in a conveying path, and a fluid is ejected from the conveying member as a conveying medium, and a fluid is ejected from the conveying member. In the method in which the transfer member is lifted and transferred without contacting the transfer path, the transfer member is formed of a porous material, and a vacuum port is provided at a central portion of the transfer path, and pressurized ports are provided at both ends of the transfer path. Is provided so that the object can be levitated while being guided to the center of the transport path and transported in a desired direction.

By providing a vacuum port at the center of the transfer path and pressurizing ports at both ends and using a porous material as the transfer member, the object to be transferred is sucked and the transfer path is drawn from both ends of the transfer path to the center. In this case, the flow of the transport medium is generated in the direction, and the pressure film formed by the transport medium becomes uniform, so that the transported object is guided to the central portion of the transport path while maintaining a very stable state. Therefore, the transported object can be stably transported along the target trajectory.

According to a fifth aspect of the present invention, in order to solve the above-mentioned problems, a conveying member having a plurality of small-diameter jetting ports is provided on a conveying path, and a fluid is jetted from the conveying member as a conveying medium, and the conveying member is ejected. In a device for lifting a transport body and transporting it without contacting a transport path, the transport member is formed of a porous material.

Since a porous material is used as the transporting member, a sophisticated drilling technique is not required unlike the transporting device described in Japanese Patent Publication No. 140496/140, so that the floating type transporting device can be easily and inexpensively manufactured. Can be manufactured.

According to the sixth aspect of the present invention, in order to solve the above-mentioned problems, a conveying member having a plurality of small-diameter ejection ports is provided in a conveying path, and a fluid is ejected from the conveying member as a conveying medium, and the conveying member is ejected. An apparatus for transporting a body without lifting and contacting a transport path, wherein the transport path has a vacuum port at a central portion and a pressurizing port at both ends of the transport path.

By providing a vacuum port at the center of the transfer path and pressurizing ports at both ends, the flow of the transfer medium is created in the direction from both ends of the transfer path to the center. , A floating type transport device capable of transporting a transport body can be provided.

According to a seventh aspect of the present invention, in order to solve the above-mentioned problem, in the floating type transport apparatus according to the sixth aspect, the transport member is formed of a porous material.

By providing a vacuum port at the center of the transfer path and pressurizing ports at both ends and using a porous material as a transfer member, the object to be transferred is sucked and the transfer path is drawn from both ends to the center. To create a flow of the transport medium in the direction
Since the pressure film formed by the transport medium becomes uniform, the transported object is guided to the center of the transport path while maintaining a very stable state. In addition, since a porous material is used as the transport member, an advanced drilling technique is not required. Therefore, it is possible to easily and inexpensively manufacture a floating transfer device capable of stably transferring the transferred object along the target track.

[0023]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a levitation type transport device according to the present invention. FIG. 1 is a perspective view of a floating-type transfer device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a propulsion pressure port. The transfer device 1 is provided with a vacuum port 2 at the center of the transfer path, and pressurized ports 3 at both ends thereof. A member 2a and a pressure conveying member 3a are arranged. Here, the transport members 2a,
3a will be described. This transport member is formed of a porous material, and in the present embodiment, a resin powder is formed by sintering using ethylene trifluoride ethylene resin. The material of the conveying member is not limited to the ethylene trifluoride chloride resin, but may be another fluorine resin. And the transport member 2
About 5100 holes having an average diameter of 0.1 mm are formed in 1a and 3a per 1 cm ² . By using a porous material as the transfer member, it is not necessary to form fine holes in the transfer member as in the related art. Further, a uniform pressure film is formed by the transport medium ejected from the fine holes.

A propulsion pressurizing port 4 is provided between each port to apply a propulsive force to the object to be transmitted.
Injection ports 5 communicating with the propulsion pressure port
As shown in FIG. 2, 5, 5,... When the transport medium is pressurized to the propulsion pressure port 4, the transport medium is obliquely ejected from the ejection ports 5, 5,. Therefore, the transfer object 10 is connected to the pressure ports 3 and 3.
Are lifted up by the carrier medium ejected from the carrier members 3a via the carrier members 3a, and the ejection ports 5, 5,.
Propelling force is given by a conveying medium which is obliquely ejected from the medium, and is conveyed in a desired direction without contact. In FIG. 2, the object is transported in the direction B.

However, in the prior art, as described above,
Due to low stability in the vertical and horizontal directions in the floating state of the transported body, the transported body has been transported in a rather unstable state. For this reason, there has been a problem that the track may be deviated from the orbit under the influence of an external air flow, vibration, or the like. First, in the present invention, the vacuum port 2 is provided at the center of the transport path to suck the object, thereby increasing the stability of the object in the vertical direction in the floating state.

A method for increasing the stability in the up-down direction in the floating state of the object to be transported will be described with reference to FIG. FIG. 3 shows the relationship between the floating clearance and rigidity (curve (1)) and the relationship between the floating clearance and weight (curve (2)) when a porous material is used for the transport member. It is a graph. Here, rigidity is
It refers to the stability of the floating clearance with respect to the change in weight of the transported body. Generally, it is said that the rigidity is high when the change in the floating clearance is small with respect to the change in weight. It can be seen from the curve (1) that the rigidity becomes maximum at a certain floating clearance, and becomes lower when the value deviates from the certain value. Also, from the curve (2), it can be seen that when the weight of the object is large, the flying clearance is small, and conversely, when the weight is small, the flying clearance is large.

Here, first, as in the prior art, the transfer member 3
A case will be described in which the transport medium is uniformly jetted from a to float the object. In this case, point a shown in FIG. 3 is obtained, indicating that the rigidity is low. This is because only the ejection (pressurization) of the transport medium causes the transferred body to float, so that the floating clearance is increased, and as a result, the rigidity is reduced. Therefore, in the present invention, a vacuum is drawn at the center of the transport path. As a result, the floating clearance is reduced by sucking the body to be transferred, and the rigidity can be increased. Further, according to experiments by the inventors, when about 20 g of the receiver was used, the pressure at both ends was 0.1 to 0.2 kg.
Assuming that f / cm ² and the vacuum pressure at the center were about 600 Torr, point b in FIG. 3 was found. in this case,
It can be seen that the rigidity can be kept high even if the weight of the receiver changes.

As described above, by providing a vacuum port at the center of the transport path and sucking the object, the floating clearance is reduced, the rigidity is increased, and the unstable state in the vertical direction is eliminated. Was completed. Therefore, the transfer object is strong against the influence of external airflow, vibration, and the like, and can be transported in a stable state.

Next, a method of preventing instability in the left-right direction, that is, meandering and deviation will be described with reference to FIGS. First, a method of using gravity applied to a transported object will be described. Pressurized conveying members 3 at both ends of the conveying path
By providing a, lift is generated only at both ends of the transported object 10 by the transport medium. Here, FIG.
In (A), since the areas S1 and S2 of receiving the pressure from the transport medium at both ends of the object 10 are equal, the lift at both ends of the object 10 is equal. Therefore, at this time, the transported object 10 is stable in the horizontal state at the center of the transport path. On the other hand, as shown in FIG. 4B, when the transported object 10 is deviated leftward from the center of the transport path due to disturbance, the transported object 1
Since the relationship between the areas receiving the pressure from the transport medium at both end portions of S0 is S1> S2, the lift at the left end of the transferred object 10 becomes larger than that at the right end, and the transferred object 10 is in a state of rising to the left. I will tilt. When tilted to the left, a difference in gravity distribution occurs between the right and left sides of the body 10 to be fed, and the force is guided rightward in the figure by the component force with respect to the gravity, and returns to the state of FIG. In addition, even if it is shifted to the right, the state returns to the state of FIG.

As described above, pressurized conveying members are provided at both ends of the conveying path, and lift is generated by the conveying medium only at both ends of the object to be transported. In addition, the object can be transported without any meandering.

Next, a method of utilizing the shear force caused by the flow of the transport medium will be described. By providing a vacuum transfer member 2a at the center of the transfer path and pressurized transfer members 3a at both ends of the transfer path, a flow of the transfer medium is created in a direction from both ends of the transfer path to the center. Here, FIG.
In this case, since the areas S3 and S4 of receiving the shearing force of the transport medium at both ends of the transported body 10 are equal, the transported body 1
0 is stable at the center of the transport path. On the other hand, FIG.
As shown in FIG. 5, when the transported object 10 is deviated leftward from the center of the transport path due to disturbance, the relationship of the areas receiving the shearing force of the transport medium at both ends of the transported body 10 becomes S3> S4. The shear force on the middle left is greater than on the right. Therefore, the target is guided to the right in the drawing due to the difference in the shearing force, and returns to the state shown in FIG. In addition, the state returns to the state shown in FIG.

As described above, the vacuum conveyance member is provided at the center of the conveyance path, and the pressurized conveyance members are provided at both ends of the conveyance path, so that the conveyance medium is moved from both ends of the conveyance path to the center. By generating the flow, it is possible to convey the object without deviating from the target conveyance trajectory and preventing meandering, similarly to the gravity utilizing method.

In the transport method of the present embodiment, since the above three types of methods are simultaneously used, all instabilities in the vertical and horizontal directions during transport of the object are eliminated. It has become possible to carry the object to be transported without deviating from the target trajectory while maintaining a very stable state.
Needless to say, even if the above-mentioned three types of methods are used individually, the object can be transported without departing from the target trajectory.

Further, in order to realize the transport method,
As in the transfer device described in Japanese Patent Publication No. 140496/1994, advanced drilling technology is not required, and a sintered body (porous material) of a fluororesin is used as a transfer member, and the upper surface of each port is used. Should be placed at Therefore, it is possible to easily and inexpensively manufacture a floating transfer device that can transfer the transfer target in a stable state without deviating from the target trajectory.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various applications are possible. For example, in the present embodiment, a propulsion pressurizing port for providing a propulsive force to the receiver is provided. It is also possible to supply the transport medium to the jetting port for use.

[0036]

According to the transfer method of the floating transfer device of the present invention, the transfer path has a transfer member having a large number of small-diameter injection ports, and the transfer member ejects a fluid as a transfer medium from the transfer member. In the method in which the body is levitated and transported without being brought into contact with the transport path, pressurizing ports are provided at both ends of the transport path, so that lift is generated by the transport medium only at both ends of the transported body. Therefore, it is possible to prevent the deviation from the target transport trajectory. Further, by providing a vacuum port at the center of the transport path, the transport medium is allowed to flow from both ends of the transport path to the center, and the transported object is caused to float while being guided to the center of the transport path, and the transport medium is transported. Since the body is sucked, the floating clearance can be reduced, the rigidity can be increased, and the unstable state in the vertical direction can be eliminated. Further, by forming the transport member from a porous material,
Since a uniform pressure film is formed by the transport medium ejected from the fine holes of the transport member, the transported object can be transported in a stable state.

Further, according to the floating transfer device of the present invention,
Having a transport member with a large number of small-diameter injection ports in the transport path,
In a device for ejecting a fluid as a transport medium from the transport member, and for transporting the object to be levitated without contacting the transport path, a pressure transport member having pressure ports at both ends of the transport path; A vacuum transport member having a vacuum port at the center of the transport path, and the transport member is formed of a porous material, such as a floating transport device described in JP-B-1-40496, Since advanced drilling technology is not required, a floating transfer device that can transfer a transferred object in a stable state without deviating from a target trajectory can be easily and inexpensively manufactured.

[Brief description of the drawings]

FIG. 1 is a perspective view of a floating type transport device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the floating transfer device in a cross section of the pressure propulsion port.

FIG. 3 is a graph showing the relationship between the flying clearance of the object and the rigidity and weight, (1) showing the relationship between the flying clearance and the rigidity, and (2) showing the relationship between the flying clearance and the weight.

FIG. 4 is an explanatory view of a transfer method (gravity utilization method) of the present invention.

FIG. 5 is a transfer method of the present invention (method of utilizing shear force of a flow).
FIG.

FIG. 6 is an explanatory diagram of a conventional transport method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Floating type conveyance apparatus 2 Vacuum port 2a Vacuum conveyance member 3 Pressurization port 3a Pressurization conveyance member 4 Propulsion pressurization port 5 Injection port 10 Subject

Claims (7)

[Claims] 1. A transport member having a plurality of small-diameter ejection ports in a transport path, wherein a fluid is ejected from the transport member as a transport medium, and a transported body is floated and transported without contacting the transport path. In the method, pressurizing ports are provided at both ends of the transport path, so that the object to be transported is floated while being guided to the center of the transport path, and can be transported in a desired direction. A method of transporting an object to be transported in a floating type transport apparatus. 2. A transporting member having a plurality of small-diameter ejection ports in a transporting path, wherein a fluid is ejected from the transporting member as a transporting medium, and a transported body is floated and transported without contacting the transporting path. In the method, the transport member is formed of a porous material, and pressurized ports are provided at both ends of the transport path to guide the object to be guided to the center of the transport path while floating, and transport in a desired direction. A method of transporting an object to be transported in a floating-type transport device, characterized in that: 3. A transporting member having a plurality of small-diameter ejection ports in a transporting path, wherein a fluid is ejected from the transporting member as a transporting medium, and the transported body is floated and transported without contacting the transporting path. In the method, a vacuum port is provided at a central portion of the transport path, and a pressurizing port is provided at both ends of the transport path so that the transport medium flows from both ends of the transport path to the central portion. Wherein the sheet is floated while being guided to the center of the conveyance path, and is conveyed in a desired direction. 4. A transporting member having a plurality of small-diameter ejection ports in a transporting path, wherein a fluid is ejected from the transporting member as a transporting medium, and a transported body is floated and transported without contacting the transporting path. In the method, the transport member is formed of a porous material, and a vacuum port is provided at a central portion of the transport path, and pressurizing ports are provided at both ends of the transport path. A method of transporting an object to be transported in a levitation type transport device, wherein the transported object can be levitated while being guided to the surface and transported in a desired direction. 5. A transporting member having a plurality of small-diameter ejection ports in a transporting path, wherein a fluid is ejected from the transporting member as a transporting medium, and a transported body is floated and transported without contacting the transporting path. In the apparatus, the transport member is formed of a porous material. 6. A transport member having a plurality of small-diameter ejection ports in a transport path, wherein a fluid is ejected from the transport member as a transport medium, and a transported body is floated and transported without contacting the transport path. In the apparatus, a levitation type transport device having a vacuum port at a center of the transport path and pressurizing ports at both ends of the transport path. 7. The floating transfer device according to claim 6, wherein the transfer member is formed of a porous material.