Conveyance system

Abstract

To provide a conveyance system capable of preventing the occurrence of problems such as an automatic conveyance device meandering and an automatic conveyance device being unable to move straight in an area where a travel guide line is missing.SOLUTION: A travel guide line 12 that guides the travel of an automatic conveyance device 8 is formed on the travel panel of a conveyance system 2. The automatic conveyance device 8 is equipped with a right servo motor that drives the right tire, a left servo motor 22 that drives the left tire 34, a front reading sensor 24 and a rear reading sensor 26 that read the travel guide line 12, and control means that controls the traveling direction of the automatic conveyance device 8. The control means reads the travel guide line 12 with the front reading sensor 24 and the rear reading sensor 26 while activating the right servo motor and the left servo motor 22 to cause the automatic conveyance device 8 to move straight, determines and stores the ratio between the number of pulses of the right servo motor and the number of pulses of the left servo motor 22, and controls the right servo motor and the left servo motor 22 based on the stored ratio to ensure straight-line travel.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a conveying system in which a traveling panel along which an automatic conveying device travels is arranged on the top plate of a processing device including multiple processing devices, and a traveling guide line for guiding the travel of the automatic conveying device is formed on the traveling panel. [Background technology]

[0002] A wafer has multiple devices such as ICs and LSIs formed on its surface, separated by planned dividing lines. The back side is ground using a grinding machine to form the wafer to the desired thickness, and then the wafer is divided into individual device chips using a cutting machine and laser processing machine. Each of the divided device chips is used in electrical equipment such as mobile phones and personal computers.

[0003] The present applicant has also developed a transport system in which a travel path is arranged using the top plate of a processing device including processing devices such as grinding devices, cutting devices, and laser processing devices, and a wafer storage device that stores multiple wafers, and an automatic transport device travels between the processing devices to transport wafers from the wafer storage device to each processing device or to transport consumables (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-013892 Summary of the Invention [Problem to be solved by the invention]

[0005] The travel motors, each fitted with an automatic transport device's tires, are arranged on either side of a guide line formed on the travel path to guide the automatic transport device. The direction of travel of the automatic transport device is controlled by the rotation speed of the travel motors arranged on the left and right. However, even slight differences in the installation accuracy of the travel motors, the characteristics of the travel motors, or the tire diameter can cause problems such as the automatic transport device meandering or being unable to travel straight through areas where the guide line is missing as needed.

[0006] An object of the present invention is to provide a conveying system that can prevent the problems of an automatic conveying device meandering and an automatic conveying device being unable to move straight through an area where a travel guide line is missing. [Means for solving the problem]

[0007] According to the present invention, there is provided the following transport system that solves the above-mentioned problems: "In a conveyance system in which a traveling panel on which an automatic conveyance device travels is arranged on the top plate of a processing device including a plurality of processing devices, and a traveling guide line for guiding the travel of the automatic conveyance device is formed on the traveling panel, The automatic transport device comprises a right servo motor for driving a right tire, a left servo motor for driving a left tire, front reading sensors disposed in front of the right tire and the left tire for reading the travel guide line, rear reading sensors disposed behind the right tire and the left tire for reading the travel guide line, and control means for controlling the traveling direction of the automatic transport device, The control means reads the travel guide line with the front reading sensor and the rear reading sensor while activating the right servo motor and the left servo motor to move the automatic conveying device in a straight line, determines and stores the ratio between the number of pulses of the right servo motor and the number of pulses of the left servo motor, and controls the right servo motor and the left servo motor based on the stored ratio to ensure straight-line movement.

[0008] The automatic transport device is preferably provided with directional casters in front of and behind the right and left tires. [Effects of the Invention]

[0009] The transport system of the present invention comprises: A conveyance system in which a travel panel on which an automatic conveyance device travels is arranged on a top plate of a processing device including a plurality of processing devices, and a travel guide line for guiding the travel of the automatic conveyance device is formed on the travel panel, The automatic transport device comprises a right servo motor for driving a right tire, a left servo motor for driving a left tire, front reading sensors disposed in front of the right tire and the left tire for reading the travel guide line, rear reading sensors disposed behind the right tire and the left tire for reading the travel guide line, and control means for controlling the traveling direction of the automatic transport device, The control means reads the travel guide lines with the front reading sensor and the rear reading sensor, operates the right servo motor and the left servo motor to make the automatic conveying device go straight, calculates and stores the ratio between the number of pulses of the right servo motor and the number of pulses of the left servo motor, and controls the right servo motor and the left servo motor based on the stored ratio to ensure straight-line travel, so that problems such as the automatic conveying device meandering or being unable to go straight in areas where the travel guide lines are missing can be prevented even if the installation accuracy or characteristics of the right and left servo motors or the diameters of the right and left tires are different. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of a transport system according to the present invention. [Figure 2] FIG. 2 is a perspective view of the automatic transport device shown in FIG. [Figure 3] FIG. 3 is a perspective view of the main body shown in FIG. 2 (with the belt unwound). [Figure 4] FIG. 2 is a control block diagram when the automatic transport device shown in FIG. 1 travels. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a transport system according to the present invention will now be described with reference to the drawings.

[0012] (Transport System 2) Referring to FIG. 1, in the conveying system 2, a traveling panel 10 along which the automatic conveying device 8 travels is disposed on the top plate 6 of the processing device 4 including a plurality of processing devices, and a traveling guide line 12 for guiding the travel of the automatic conveying device 8 is formed on the traveling panel 10.

[0013] The processing equipment 4 includes a storage device 4a for storing articles and first, second, and third processing devices 4b, 4c, and 4d to which the articles in the storage device 4a are transported by an automatic transport device 8. Examples of articles stored in the storage device 4a include workpieces such as semiconductor wafers to be processed in the first to third processing devices 4b to 4d, and processing tools used when processing in any of the first to third processing devices 4b to 4d. Examples of processing tools used when processing in any of the first to third processing devices 4b to 4d include cutting blades used when cutting the workpieces, and grinding wheels with grinding stones used when grinding the workpieces to thin them. In this embodiment, one storage device 4a and three processing devices 4b to 4d are provided as the processing equipment 4, but the number and combination of processing devices 4 can be set as desired.

[0014] A traveling panel 10 is disposed on the top plate 6 of the processing equipment 4, and a plurality of processing equipments 4 are connected to one another by the traveling panel 10. An article delivery opening 10a is formed in the traveling panel 10. Although not shown, a delivery opening corresponding in position and size to the delivery opening 10a of the traveling panel 10 is also formed in the top plate 6 of the processing equipment 4. Articles are delivered between the automatic conveying equipment 8 and the processing equipment 4 through the delivery opening 10a of the traveling panel 10 and the delivery opening in the top plate 6 of the processing equipment 4.

[0015] Furthermore, on the upper surface of the traveling panel 10, there are formed travel guide lines 12 for guiding the travel of the automatic conveying device 8. Therefore, the automatic conveying device 8 travels on the traveling panel 10 along the travel guide lines 12, and is able to transport the articles received from the storage device 4a to the first to third processing devices 4b to 4d. The traveling panel 10 is also provided with a fall prevention wall 14 for preventing the automatic conveying device 8 from falling off the traveling panel 10.

[0016] (Main body 16 of automatic conveying device 8) 2 and 3, the automatic transport device 8 includes a main body 16 and a cover 18 (see FIG. 2) that covers the main body 16. The main body 16 includes a right servo motor 20 (see FIG. 3), a left servo motor 22, a front reading sensor 24 (see FIG. 2), a rear reading sensor 26, and a control means 28 (see FIG. 3).

[0017] (Right servo motor 20, left servo motor 22) As shown in FIG. 3 , the right servo motor 20 drives the right tire 30 and is disposed on the right side of the frame 32 of the main body 16. The left servo motor 22 drives the left tire 34 and is disposed on the left side of the frame 32. Swivel casters 36 are disposed in front of and behind the right tire 30 and the left tire 34. A pair of swivel casters 36 are provided on the left and right sides of the front side of the frame 32, and another pair of swivel casters 36 are provided on the left and right sides of the rear side of the frame 32 (a total of four). In the automatic transport device 8, the rotational speed and rotation direction of the right tire 30 and the left tire 34 are adjusted by the right servo motor 20 and the left servo motor 22, so that the automatic transport device 8 can move forward, backward, turn right, turn left, or spin turn (turn on the spot around the vertical center axis of the automatic transport device 8).

[0018] (Front reading sensor 24, rear reading sensor 26) The front reading sensor 24 is disposed in front of the right tire 30 and the left tire 34, and is attached to the left-right central portion of the front lower surface of the frame 32. The rear reading sensor 26 is disposed behind the right tire 30 and the left tire 34, and is attached to the left-right central portion of the rear lower surface of the frame 32. Both the front reading sensor 24 and the rear reading sensor 26 read the travel guide lines 12 formed on the travel panel 10 and send the reading results to the control means 28.

[0019] (Control means 28) The control means 28 is composed of a computer having a processor and memory, and controls the traveling direction of the automatic transport device 8. As shown in FIG. 4, the control means 28 receives the reading results of the front reading sensor 24 and the rear reading sensor 26. Based on the reading results, the control means 28 controls the driver 38, causing the driver 38 to output the required drive current to the right servo motor 20 and the left servo motor 22. In this way, the control means 28 controls the traveling direction of the automatic transport device 8. The control means 28 and the driver 38 are supplied with power from a battery 40.

[0020] Continuing the explanation with reference to Figure 3, a rectangular opening 42 is formed in the center of the frame 32 of the main body 16. A front support wall 44 extending upward is provided at the front end of the opening 42. Meanwhile, a rear support wall 46 extending upward is provided at the rear end of the opening 42. A belt 50 attached to a cassette 48 that stores articles passes through the opening 42. A belt winding means 52 is attached to the frame 32 and winds up the belt 50 to raise and lower the cassette 48.

[0021] (Cassette 48) Cassette 48 is formed in a box shape with a vertical dimension (thickness) that is smaller than the dimensions in the front-rear and left-right directions. Cassette 48 has a storage section 48a that stores articles and a flip-up cover section 48b that opens and closes an opening (not shown) of storage section 48a.

[0022] (Belt 50) The belt 50 has two right-side belts 50a spaced apart in the front-to-rear direction and extending upward from the upper right surface of the storage section 48a of the cassette 48, and two left-side belts 50b spaced apart in the front-to-rear direction and extending upward from the upper left surface of the storage section 48a of the cassette 48.

[0023] (Belt winding means 52) The belt winding means 52 includes a right guide roller 54 that guides the two right belts 50a, a left guide roller 56 that guides the two left belts 50b, a winding roller 58 that winds up the right belt 50a and the left belt 50b, and a winding motor 60 that rotates the winding roller 58. The right guide roller 54, the left guide roller 56, and the winding roller 58 are rotatably supported by the front support wall 44 and the rear support wall 46 of the frame 32. The right guide roller 54 is disposed on the right side of the main body 16, and the left guide roller 56 is disposed on the left side of the main body 16. The winding roller 58 is disposed between the right guide roller 54 and the left guide roller 56, and the winding motor 60 is mounted on the upper rear surface of the frame 32. The drive current for the winding motor 60 is output from the driver 38.

[0024] In the belt winding means 52, the winding motor 60 is operated in the winding direction to wind the right belt 50a and the left belt 50b onto the winding roller 58, thereby lifting the cassette 48. In addition, the belt winding means 52 is configured to operate the winding motor 60 in the unwinding direction to unwind the right belt 50a and the left belt 50b from the winding roller 58, thereby lowering the cassette 48.

[0025] (Cover 18 of automatic transport device 8) 2, the cover 18 of the automatic conveying device 8 has a top plate 62 and side walls 64. The top plate 62 is formed in a rectangular shape with rounded corners. The side walls 64 are formed in a rectangular cylindrical shape extending downward from the outer periphery of the top plate 62.

[0026] (Adjustments to ensure straight-line driving) To ensure straightness, the control means 28 of the automatic transport device 8 performs the following adjustments at the location where the travel guide line 12 is formed (not necessarily on the travel panel 10).

[0027] In making adjustments to ensure straightness, the control means 28 operates the right servo motor 20 and the left servo motor 22 to cause the automatic conveying device 8 to travel straight a predetermined distance (for example, approximately 1 meter). The travel speed of the automatic conveying device 8 at this time may be slower than the speed when conveying articles. When traveling straight, the control means 28 reads the travel guide line 12 with the front reading sensor 24 and the rear reading sensor 26, and controls the right servo motor 20 and the left servo motor 22 to cause the automatic conveying device 8 to travel straight so that the read travel guide line 12 is positioned midway between the right tire 30 and the left tire 34. The control means 28 then determines and stores the ratio between the number of pulses of the right servo motor 20 and the left servo motor 22 during straight travel. In this manner, the control means 28 performs adjustments to ensure straightness.

[0028] After making the adjustments to ensure straightness, the control means 28 controls the right servo motor 20 and the left servo motor 22 based on the stored ratio in areas where the travel guide line 12 is straight or areas where the travel guide line 12 is missing when transporting an article, thereby ensuring straightness of the automatic conveying device 8. This prevents problems such as the automatic conveying device 8 meandering or being unable to move straight in areas where the travel guide line 12 is missing, even if the installation accuracy or characteristics of the right servo motor 20 and the left servo motor 22 or the diameters of the right tire 30 and the left tire 34 are different.

[0029] It is preferable that the control means 28 periodically performs adjustments related to ensuring straightness. If the ratio has changed by a predetermined value or more from the ratio at the time of shipment, it can be said that adjustment or replacement of parts is necessary. Therefore, by periodically performing adjustments related to ensuring straightness, parts can be adjusted or replaced at the appropriate time, and the occurrence of malfunctions in the conveyance system 2 can be suppressed.

[0030] Next, an example of transporting a workpiece such as a semiconductor wafer in the transport system 2 will be described.

[0031] In the conveyance system 2, first, a workpiece is transferred from the storage device 4a to the automatic conveyance device 8. At this time, the automatic conveyance device 8 stops at the transfer opening 10a of the traveling panel 10 installed above the storage device 4a. Although the travel guide line 12 is missing at the transfer opening 10a, the automatic conveyance device 8 is able to travel straight even above the transfer opening 10a because it has made adjustments to ensure straight travel.

[0032] Next, the belt winding means 52 lowers the cassette 48 from the automatic conveying device 8 through the delivery opening 10a of the traveling panel 10 and the delivery opening of the top plate 6 of the storage device 4a, and the cassette 48 is sent into the storage device 4a. Once the cassette 48 is positioned at a predetermined position within the storage device 4a, the workpieces are stored in the cassette 48 by the transport means (for example, a robot hand) of the storage device 4a. Then, the belt winding means 52 raises the cassette 48 containing the workpieces, and the cassette 48 is removed from the storage device 4a. In this manner, the workpieces are transferred from the storage device 4a to the automatic conveying device 8.

[0033] After the workpiece is handed over from the storage device 4a to the automatic transport device 8, the automatic transport device 8 transports the workpiece to the first processing device 4b. At this time, the automatic transport device 8 travels on the traveling panel 10 while reading the travel guide line 12 with the front reading sensor 24 and the rear reading sensor 26, and moves from the storage device 4a to the first processing device 4b. Because the automatic transport device 8 performs adjustments to ensure straightness, it does not meander in the area where the travel guide line 12 is straight.

[0034] When the automatic conveying device 8 arrives at a predetermined position above the first processing device 4b (the position where the transfer opening 10a of the traveling panel 10 is formed), the cassette 48 is lowered from the automatic conveying device 8 through the transfer opening 10a of the traveling panel 10 and the transfer opening of the top plate 6 of the first processing device 4b, and the cassette 48 is sent into the first processing device 4b.

[0035] After the workpiece is transported to the first processing device 4b, the first processing device 4b performs the required processing on the workpiece. When the cassette 48 is lowered and positioned at a predetermined position within the first processing device 4b, the workpiece is removed from the cassette 48 by the transport means (e.g., a robot hand) of the first processing device 4b. Then, the first processing device 4b performs the required processing on the workpiece. Thereafter, the transport means stores the processed workpiece in a cassette 48 of the same automatic transport device 8 or a different automatic transport device 8. Once the processed workpiece is stored in the cassette 48, the cassette 48 is raised and removed from the first processing device 4b.

[0036] After the required processing is performed on the workpiece in the first processing device 4b, the workpiece is transported by the automatic transport device 8 to the second processing device 4c, where the required processing is performed on the workpiece. The steps for transporting the workpiece to the second processing device 4c are substantially the same as the steps for transporting the workpiece to the first processing device 4b, and therefore a description thereof will be omitted.

[0037] After the required processing is performed on the workpiece in the second processing device 4c, the workpiece is transported to the third processing device 4d by the automatic transport device 8, where the required processing is performed on the workpiece. After that, the automatic transport device 8 transports the workpiece to the storage device 4a, where the processed workpiece is stored.

[0038] As described above, the control means 28 for the automatic conveyance device 8 of this embodiment reads the travel guide lines 12 with the front reading sensor 24 and the rear reading sensor 26, while operating the right servo motor 20 and the left servo motor 22 to move the automatic conveyance device 8 in a straight line, determines and stores the ratio between the number of pulses of the right servo motor 20 and the number of pulses of the left servo motor 22, and controls the right servo motor 20 and the left servo motor 22 based on the stored ratio to ensure straight-line movement. Therefore, even if the installation accuracy and characteristics of the right servo motor 20 and the left servo motor 22 or the diameters of the right tires 30 and the left tires 34 are different, problems such as the automatic conveyance device 8 meandering or being unable to move straight through areas where the travel guide lines 12 are missing can be prevented. [Explanation of symbols]

[0039] 2:Transport system 4: Processing equipment 4a: Storage device 4b: First processing device 4c: Second processing equipment 4d: Third processing equipment 6: Top plate 8: Automatic transport device 10: Travel panel 12: Driving guidance line 20: Right servo motor 22: Left servo motor 24: Front reading sensor 26: Rear reading sensor 28: Control means 30: Right tire 34: Left tire 36: Free-direction caster

Claims

1. A conveyance system in which a travel panel on which an automatic conveyance device travels is arranged on a top plate of a processing device including a plurality of processing devices, and a travel guide line for guiding the travel of the automatic conveyance device is formed on the travel panel, The automatic transport device comprises a right servo motor for driving a right tire, a left servo motor for driving a left tire, front reading sensors disposed in front of the right tire and the left tire for reading the travel guide line, rear reading sensors disposed behind the right tire and the left tire for reading the travel guide line, and control means for controlling the traveling direction of the automatic transport device, The control means reads the travel guide line with the front reading sensor and the rear reading sensor while activating the right servo motor and the left servo motor to move the automatic conveying device in a straight line, determines and stores the ratio between the number of pulses of the right servo motor and the number of pulses of the left servo motor, and controls the right servo motor and the left servo motor based on the stored ratio to ensure straight-line movement.

2. 2. The transport system according to claim 1, wherein said automatic transport device is provided with directional casters in front of and behind said right and left tires.

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