Crown block system and control method thereof

Abstract

The crown block system comprises a rail assembly, a storage assembly and a crown block assembly, the rail assembly comprises a first rail and second rails which are arranged in parallel, and the second rails are arranged above process machines in a one-to-one correspondence mode; the storage assembly comprises storage racks arranged in one-to-one correspondence with the process machines, and each storage rack is arranged close to the corresponding process machine and located below the first track. The crown block assembly comprises a first crown block and a second crown block, and the first crown block is located on the first track and used for circulation of the wafer box between the different storage racks; the second crown block is located on the second track and used for circulation of the wafer box between the corresponding process machine table and the storage frame. The method can effectively solve the problem that the waiting time of a process machine is long due to the fact that the crown block is not responded in time.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor processing, and in particular to an overhead crane system and a control method thereof. Background Art

[0002] In the semiconductor manufacturing process, the overhead crane system is often used to transfer wafer boxes loaded with wafers between different process machines. For example, when a process machine has processed the wafers in a wafer box and needs to process the wafers in the next wafer box, the overhead crane system will first dispatch an unloaded overhead crane to transport the wafer box processed on the current process machine to the next process machine, and then dispatch another overhead crane to place the wafer box to be processed on the current process machine. However, in this process, due to the long transportation path of the overhead crane, the overhead crane may not respond in time when the overhead crane system is dispatched, resulting in a long waiting time for the process machine. Summary of the invention

[0003] In order to overcome the above disadvantages, the object of the present invention is to provide an overhead crane system and a control method thereof, which can effectively solve the problem of long waiting time of process machines caused by untimely response of the overhead crane.

[0004] An overhead travelling vehicle system according to an embodiment of the present invention comprises: A track assembly, the track assembly comprising a first track and a second track arranged in parallel, wherein the second tracks are arranged above the process machine in a one-to-one correspondence; A storage component, the storage component comprising storage racks arranged in one-to-one correspondence with the process machines, each of the storage racks being arranged close to the corresponding process machine and located below the first track; The overhead crane assembly includes a first overhead crane and a second overhead crane. The first overhead crane is located on the first track and is used for transferring wafer boxes between different storage racks. The second overhead crane is located on the second track and is used for transferring wafer boxes between corresponding process machines and storage racks. Further, the first overhead crane includes a first walking part, a first lifting part, and a first grasping part. The first walking part moves along the first track. The first lifting part is installed on the first walking part and can drive the first grasping part to move up and down. When the first grasping part is located at the highest position of movement, the vertical distance between the first overhead crane and the storage rack is not less than the sum of the heights of the two wafer boxes.

[0005] Furthermore, the second car includes a second walking part, a second lifting part, a second transverse moving part, and a second grabbing part. The second walking part moves along the second track; the second lifting part is installed on the second walking part, and can drive the second transverse moving part to move up and down; the second grabbing part is installed on the second transverse moving part, and can move horizontally in a direction close to or away from the first track under the action of the second transverse moving part.

[0006] Furthermore, when the second gripping part is at the highest moving position, the vertical distance between the second carriage and the storage rack is not less than the height of a wafer box, and the vertical distance between the second carriage and the storage rack is less than the sum of the heights of the two wafer boxes.

[0007] Furthermore, the height of the second track is lower than the height of the first track.

[0008] Furthermore, the storage rack is located above the corresponding process machine; and along the length direction of the first track, the storage rack is provided with a plurality of storage positions for placing wafer boxes.

[0009] The present invention also provides a method for controlling an overhead crane system, which is used for any of the above-mentioned overhead crane systems and comprises the following steps: The first track is divided into pick-and-place track segments corresponding to the storage racks, and the pick-and-place track segments are located directly above the corresponding storage racks; A traffic light assembly is arranged on the first track in one-to-one correspondence with the storage rack; when the second car takes and places the wafer box on the storage rack, the red light of the traffic light assembly is turned on, and the first car located outside the corresponding take-and-place track section cannot enter the take-and-place track section. Furthermore, position information codes for scanning by the first overhead crane and the second overhead crane are respectively provided on the pick-and-place track section and the second track; when the first overhead crane is located on the pick-and-place track section, and the second overhead crane needs to pick up and place a wafer box from the corresponding storage rack, the control system controls the second overhead crane to avoid the first overhead crane according to the position information codes scanned by the first overhead crane and the second overhead crane.

[0010] Furthermore, when the second overhead crane picks up and places a wafer box on the storage rack, and the first overhead crane is not on the corresponding pick-up and placement track segment, after the second overhead crane places the processed wafer box on the storage rack, the second overhead crane can move along the second track to any storage position of the storage rack when the second gripping part has not been retracted laterally.

[0011] Furthermore, when the second overhead crane picks up and places the wafer box on the storage rack and the first overhead crane is on the corresponding pick-up and placement track segment, the control system determines whether the storage position where the second overhead crane places the processed wafer box is adjacent to the storage position where the second overhead crane picks up the wafer box to be processed. If they are adjacent, after the second overhead crane places the processed wafer box, the second overhead crane can move along the second track to the adjacent storage position where the wafer box to be processed is stored when the second gripping part has not retracted laterally. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the structure of an overhead traveling vehicle system according to an embodiment of the present invention; Figure 2 It is a structural schematic diagram of the overhead travelling vehicle system from another perspective of an embodiment of the present invention.

[0013] In the figure: 1-first track; 2-second track; 21-stop plate; 3-processing machine; 4-storage rack; 5-first traveling device; 51-first walking part; 52-first lifting part; 53-first grasping part; 6-second traveling device; 61-second walking part; 62-second lifting part; 63-second lateral moving part; 64-second grasping part; 7-wafer box; 8-wiring rod. DETAILED DESCRIPTION The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0014] Example See attached Figure 1-2 As shown, a crane system of the present invention includes a track assembly, a storage assembly, and a crane assembly. The track assembly includes a first track 1 and a second track 2 arranged in parallel, wherein the second track 2 is arranged above the process machine 3 in a one-to-one correspondence. The storage assembly includes storage racks 4 arranged in a one-to-one correspondence with the process machine 3, and each storage rack 4 is arranged close to the corresponding process machine 3 and is located below the first track 1. The crane assembly includes a first crane 5 and a second crane 6. The first crane 5 is located on the first track 1 and is used for the flow of wafer boxes 7 between different storage racks 4. The second crane 6 is located on the second track 2 and is used for the flow of wafer boxes 7 between the corresponding process machine 3 and the storage rack 4.

[0015] In this embodiment, each process machine 3 is equipped with an independent second track 2 and storage rack 4, and the movement of the second car 6 on the second track 2 realizes the transfer of the wafer box 7 between the corresponding process machine 3 and the storage rack 4, that is, the wafer box 7 processed on the process machine 3 can be transported to the storage rack 4 via the second car 6, and the wafer box 7 to be processed on the storage rack 4 can also be transported to the process machine 3 via the second car 6; and the setting of the first track 1 and the first car 5 can realize the transfer of the wafer box 7 between multiple storage racks 4, and then realize the transfer of the wafer box 7 between multiple process machines 3, meeting the needs of the transfer of the wafer box 7 between different process machines 3. It can be understood that the first track 1 is connected to the storage racks 4 corresponding to multiple process machines 3, and the first car 5 can go back and forth between different storage racks 4 along the first track 1; and the second track 2 corresponds to only one process machine 3, and the second car 6 can only go back and forth between the corresponding process machine 3 and the storage rack 4 along the second track 2.

[0016] Since the storage rack 4 is arranged close to the corresponding process machine 3, the length of the second track 2 is relatively short, and the moving distance of the second car 6 between the process machine 3 and the storage rack 4 is also relatively short. Therefore, the second car 6 can respond to the wafer box retrieval demand on the process machine 3 in time to reduce the waiting time of the process machine 3.

[0017] It should be noted that the wafer box 7 taken away from the storage rack 4 by the first stage carriage 5 is the wafer box 7 processed by the corresponding process machine 3, and the wafer box 7 placed on the storage rack 4 by the first stage carriage 5 is the wafer box 7 to be processed by the corresponding process machine 3. In other words, the first stage carriage 5 can take away the wafer box 7 processed by the process machine 3 from the storage rack 4 of the previous process machine 3, and transport the wafer box 7 to the storage rack 4 corresponding to the next process machine 3 for processing by the next process machine 3. In addition, when the first stage carriage 5 carrying the wafer box 7 moves to the top of the storage rack 4, the first stage carriage 5 can continuously perform two actions: placing the wafer box 7 to be processed by the corresponding process machine 3 and taking away the wafer box 7 processed by the corresponding process machine 3, thereby improving the working efficiency of the first stage carriage and the circulation efficiency of the wafer box.

[0018] In practical applications, since the process machine 3 has high requirements for the processing accuracy of the wafer box 7, the accuracy requirements for taking and placing the wafer box 7 on the process machine 3 are also relatively high. Therefore, in the prior art, the overhead traveling crane has high walking accuracy requirements near the process machine 3 and relatively slow walking speed, which will undoubtedly affect the overall circulation efficiency of the wafer box. In this embodiment, the circulation of the wafer box on the process machine 3 is realized by the second overhead traveling crane 6 walking on the second track 2, and the second track 2 is independent of the first track 1, and because the second track 2 is short, the walking speed of the second overhead traveling crane 6 along the second track 2 itself will not be too fast, and it is easier to meet the accuracy requirements for taking and placing the wafer box; and the first overhead traveling crane 5 walking on the first track 1 will not contact the wafer box 7 on the process machine 3, therefore, the walking of the first overhead traveling crane 5 along the first track 1 is not affected by the accuracy requirements for taking and placing the wafer box by the process machine 3, and the walking speed of the first overhead traveling crane 5 can be set faster to improve the circulation efficiency of the wafer box 7 between different process machines 3.

[0019] In some embodiments, see Appendix Figure 2 As shown, the storage rack 4 is suspended directly below the first track 1, and is provided with a plurality of storage positions arranged along the length direction of the first track 1. Since the storage rack 4 is located directly below the first track 1, when the first crane 5 moves along the first track 1 to directly above the storage rack 4, it only needs to be lifted and lowered to complete the wafer box 7 pick-up and placement action, thereby reducing the difficulty of the first crane 5 to pick up and place the wafer box 7.

[0020] Since the first track 1 needs to connect the storage racks 4 corresponding to multiple process machines 3, and the layout of the process machines 3 is relatively complex, multiple forks may be set on the first track 1 for the first car 5 to change direction and move to different process machines 3. In order to ensure the flexibility of the first car 5 to change direction, the size and weight of the first car 5 should not be too large. The second car 6 only moves in a straight line along the second track 2, and the second car 6 does not need to change direction during the movement. Therefore, there are not many restrictions on the size and space of the second car 6 during design.

[0021] Based on this, in some embodiments, see the attached Figure 1-2As shown, the first carriage 5 includes a first walking part 51, a first lifting part 52, and a first grabbing part 53. The first walking part 51 walks along the first track 1. The first lifting part 52 is installed on the first walking part 51 and can drive the first grabbing part 53 to move up and down. The first grabbing part 53 is used to grab or release the wafer box 7. The second carriage 6 includes a second walking part 61, a second lifting part 62, a second traverse part 63, and a second grabbing part 64. The second walking part 61 walks along the second track 2; the second lifting part 62 is installed on the second walking part 61 and can drive the second traverse part 63 to move up and down; the second grabbing part 64 is installed on the second traverse part 63 and can move horizontally in the direction close to or away from the first track 1 under the action of the second traverse part 63. The second grabbing part 64 is used to grab or release the wafer box 7. For the convenience of the following description, the horizontal movement of the second gripping portion 64 toward the first rail 1 is referred to as the lateral extension of the second gripping portion 64 , and the horizontal movement of the second gripping portion 64 toward the direction away from the first rail 1 is referred to as the lateral retraction of the second gripping portion 64 .

[0022] The transport process of the first car 5 is as follows: when it is necessary to take away the processed wafer box 7 on the storage rack 4, the first car 5 moves to the storage rack 4 and is located directly above the processed wafer box 7, and the first lifting part 52 drives the first grabbing part 53 to move down to grab the processed wafer box 7; then the first lifting part 52 drives the first grabbing part 53 to move up and drives the wafer box 7 to leave the storage rack 4, at this time, the first car 5 can carry the wafer box 7 to the storage rack 4 corresponding to the next process machine 3. Similarly, when it is necessary to place the wafer box 7 to be processed on the storage rack 4, the first car 5 drives the wafer box 7 to be processed to move directly above the vacant storage position of the storage rack 4, the first lifting part 52 drives the first grabbing part 53 to move down to place the wafer box 7 to be processed on the vacant storage position, and the first grabbing part 53 immediately releases the wafer box 7; then the first lifting part 52 drives the first grabbing part 53 to move up.

[0023] The handling process of the second car 6 is as follows: when it is necessary to take away the wafer box 7 processed on the process machine 3, the second car 6 moves to the top of the process machine 3, the second lifting part 62 drives the second transverse part 63 and the second grabbing part 64 to move down to the position of grabbing the wafer box 7, and the second grabbing part 64 immediately grabs the wafer box 7 on the process machine 3, and the second lifting part 62 drives the second transverse part 63 and the second grabbing part 64 to move up, which can drive the wafer box 7 away from the process machine 3; then the second car 6 moves to a place close to the storage rack 4 , and makes the second grabbing part 64 face the empty storage position; then the second transverse moving part 63 drives the second grabbing part 64 to move laterally and extend until the second grabbing part 64 is located directly above the empty storage position, and then the second lifting part 62 drives the second transverse moving part 63 and the second grabbing part 64 to move downward to place the wafer box 7 on the empty storage position, and the second grabbing part 64 immediately releases the wafer box 7; the second lifting part 62 drives the second transverse moving part 63 and the second grabbing part 64 to move upward, and at the same time, the second transverse moving part 63 drives the second grabbing part 64 to move laterally and retract.

[0024] Similarly, when it is necessary to transport the wafer box 7 to be processed on the storage rack 4 to the process machine 3, the second car 6 moves to the storage position close to the storage rack 4 where the wafer box 7 to be processed is placed, and the second transverse moving part 63 drives the second grabbing part 64 to move transversely and extend until the second grabbing part 64 is located directly above the wafer box 7 to be processed; the second lifting part 62 then drives the second transverse moving part 63 and the second grabbing part 64 to descend until the second grabbing part 64 grabs the wafer box 7 to be processed; then the second lifting part 62 drives the second transverse moving part 63 and the second grabbing part 64 to move downward. The second lifting part 62 drives the second lateral moving part 63 and the second grabbing part 64 to move upward. At this time, the wafer box 7 to be processed is always grabbed on the second grabbing part 64. The next car 6 moves to the top of the process machine 3, and the second lifting part 62 drives the second lateral moving part 63 and the second grabbing part 64 to descend until the wafer box 7 to be processed is located on the process machine 3. The second grabbing part 64 immediately releases the wafer box 7, and the second lifting part 62 drives the second lateral moving part 63 and the second grabbing part 64 to move upward. At this time, the process machine 3 can process the wafer box 7.

[0025] Since the storage rack 4 is arranged directly below the first track 1, when the first car 5 moves along the first track 1, the first car 5 only needs to move up and down to contact the storage rack 4. Therefore, for the first car 5, the first travel part 51, the first lifting part 52 and the first grabbing part 53 can cooperate to complete the transportation action of the wafer box 7 on the storage rack 4, and at the same time, the moving structure of the first car 5 can be simplified (the transverse moving part is omitted), so that the structure of the first car 5 is more streamlined and the weight is relatively reduced. The streamlined structure and lighter weight reduce the inertia of the first car 5 walking along the first track 1, and the acceleration and deceleration time of the first car 5 is shortened, which is conducive to the first car 5 to travel on the first track 1 at a higher speed, thereby improving the circulation efficiency of the wafer box 7 between different process machines 3.

[0026] The second car 6 has no size or weight restrictions, and since the first track 1 and the second track 2 are arranged in parallel, the process machine 3 is located below the second track 2, and the storage rack 4 is located directly below the first track 1. Therefore, in order to ensure the flow of wafer boxes between the process machine 3 and the storage rack 4, the second car 6, in addition to the second walking part 61, the second lifting part 62 and the second grasping part 64, is also provided with a second lateral movement part 63 that can drive the second grasping part 64 to move horizontally.

[0027] In addition, it should be noted that the overhead crane in the prior art is usually also equipped with a rotating mechanism, which is to compensate for the position deviation of the wafer box relative to the process machine when the position of the overhead crane stopping on the process machine is deviated due to high-speed driving, so as to ensure the processing accuracy of the process machine. In this embodiment, the wafer box 7 on the process machine 3 is taken and placed by the second car 6, and the second car 6 moves along the second track 2. Since the second track 2 is short, the driving speed of the second car 6 on the second track 2 is relatively slow, and the position of the wafer box 7 placed on the process machine 3 is relatively accurate. Therefore, there will be no problem of deviation in the parking position on the process machine 3 due to the excessive speed of the second car 6. The first car 5 moves along the first track 1, and the first car 5 does not touch the wafer box 7 on the process machine 3. Therefore, even if the first car 5 has a parking position deviation when traveling at high speed along the first track 1, it will not affect the position accuracy of the wafer box on the process machine 3. Therefore, in this embodiment, the first car 5 and the second car 6 do not need to be provided with a rotating mechanism, which further simplifies the structure of the first car 5 and the second car 6, which is conducive to reducing the size and weight of the first car 5.

[0028] Since the second carriage 6 needs to take and place the wafer box 7 from the process machine 3, and the process machine 3 has a high requirement for the position accuracy of the wafer box 7, in order to ensure the placement accuracy of the second carriage 6, in some embodiments, the second lifting part 62 adopts a toothed belt drive (gear and toothed belt meshing drive). Since the second lifting part 62 adopts a toothed belt drive, the lifting height of the second traverse part 63 and the second grabbing part 64 will be more accurate, thereby improving the accuracy of the second grabbing part 64 grabbing the wafer box position, avoiding the problem of the wafer box 7 bumping or not being placed in place during the placement process.

[0029] Since the first crane 5 only takes and places the wafer box 7 on the storage rack 4, the position accuracy requirement of the wafer box 7 is relatively low, and the first crane 5 has the requirements of weight reduction and compact structural design. Therefore, the first lifting part 52 of the first crane 5 can be driven by an ordinary belt (toothless belt) to reduce the size and weight of the first lifting part 52 as much as possible.

[0030] In some embodiments, the storage rack 4 is arranged at a height higher than that of the process machine 3. This arrangement makes the lifting and moving path required for the first crane 5 to take and place the wafer box 7 from the storage rack 4 relatively short compared to taking and placing the wafer box 7 from the process machine 3, and the belt length and diameter of the first lifting part 52 after winding are relatively small, which is conducive to making the structure of the first crane 5 more compact, and the overall size of the first crane 5 can be further reduced. The reduction in the size of the first crane 5 can not only make the movement of the first crane 5 more flexible, but also facilitate the first track 1 to run more first cranes 5 within a unit length, further improving the circulation efficiency of the wafer box 7.

[0031] In addition to taking and placing wafer boxes 7 from the storage rack 4, the first car 5 also needs to transport wafer boxes 7 between different storage racks 4. In order to prevent the first car 5 from accidentally hitting the wafer boxes 7 on the storage rack 4 during the process of transporting the wafer boxes 7, in some embodiments, the distance between the first car 5 and the storage rack 4 is limited. Specifically, when the first grabbing portion 53 is at the highest position of movement, the vertical distance between the first car 5 and the storage rack 4 (the vertical distance between the bottom end of the first car 5 and the top end of the storage rack 4) is not less than the sum of the heights of the two wafer boxes 7. This arrangement allows the first car 5 with the wafer boxes 7 grabbed to still move smoothly on the first track 1 above the storage rack 4 when there are wafer boxes 7 grabbed on the first car 5 and there are wafer boxes 7 stored on the storage rack 4.

[0032] In some embodiments, in order to improve the speed of the second car 6 in picking up and placing the wafer box 7, the moving height of the second car 6 is limited. Specifically, when the second gripping part 64 is at the highest position of the movement, the vertical distance between the second car 6 and the storage rack 4 (the vertical distance between the bottom end of the second car 6 and the top end of the storage rack 4) is not less than the height of one wafer box 7, and the vertical distance between the second car 6 and the storage rack 4 is less than the sum of the heights of two wafer boxes 7. In other words, the highest position of the second gripping part 64 should be higher than the height of the wafer box 7 on the storage rack 4, but lower than the highest position of the first gripping part 53 of the first car 5. In this way, it is ensured that the second gripping part 64 can smoothly grab the wafer box 7 on the storage rack 4, and the lifting path of the second gripping part 64 can be reduced as much as possible, saving the time of picking up and placing the wafer box 7, and improving the efficiency of the second car 6 in picking up and placing the wafer box 7, thereby reducing the waiting time of the process machine 3.

[0033] Furthermore, the height of the second track 2 is lower than that of the first track 1, thereby reducing the height difference between the second track 2 and the process machine 3, and between the second track 2 and the storage rack 4, shortening the lifting path of the second car 6 in the process of taking and placing the wafer box 7 on the process machine 3 or the storage rack 4, and improving the efficiency of the second car 6 in taking and placing the wafer box 7 from the process machine 3 and the storage rack 4.

[0034] In some embodiments, the first rail 1 and the second rail 2 are both suspended from the ceiling, and the second rail 2 is detachably connected to the first rail 1 through the wiring rod 8. The wiring rod 8 can be used to lead the Litz wire on the first rail 1 to the second rail 2, so as to power the second trolley 6. At the same time, the wiring rod 8 can limit the distance between the second rail 2 and the first rail 1, ensuring that the second rail 2 and the first rail 1 remain parallel to each other, so as to avoid the second trolley 6 from being unable to smoothly pick up and place the wafer box 7 on the storage rack 4. In addition, the vibration of the first rail 1 caused by the high-speed driving of the first trolley 5 can also be transmitted to the second rail 2 through the wiring rod 8, which helps to reduce the vibration of the first rail 1 and reduce the risk of damage to the first rail 1.

[0035] In some embodiments, stop plates 21 are further provided at both ends of the second track 2 to prevent the second carriage 6 from accidentally falling off the second track 2 .

[0036] During the operation of the first crane 5 and the second crane 6, it is possible that the first crane 5 and the second crane 6 take and place the wafer box 7 on the same storage rack 4. If the first crane 5 and the second crane 6 operate improperly, the first crane 5 and the second crane 6 may interfere with each other and fail to take and place the wafer box 7 normally. Based on this, the present invention also provides a method for controlling a crane system, comprising the following steps: The first track 1 is divided into pick-and-place track segments corresponding to the storage racks 4, and the pick-and-place track segments are located directly above the corresponding storage racks 4; A traffic light assembly is arranged on the first track 1 in one-to-one correspondence with the storage rack 4; when the second car 6 takes and places the wafer box 7 on the storage rack 4, the red light of the traffic light assembly is turned on, and the first car 5 located outside the corresponding pick-up and placement track section cannot enter the pick-up and placement track section.

[0037] By dividing the pick-and-place track segments, the area where the first car 5 and the second car 6 may interfere with each other can be limited. By setting the traffic light assembly, an alarm can be given as to whether the second car 6 is picking up and placing the wafer box 7 on the storage rack 4. When the second car 6 is picking up and placing the wafer box 7 on the storage rack 4, the red light of the traffic light assembly lights up, indicating that the pick-and-place track segment directly above the storage rack 4 is stationary and passable; when the second car 6 is not picking up and placing the wafer box 7 on the storage rack 4, the green light of the traffic light assembly lights up, indicating that the pick-and-place track segment directly above the storage rack 4 is passable.

[0038] For example, when the second car 6 takes and places the wafer box 7 on the storage rack 4, the red light of the corresponding traffic light assembly lights up. At this time, if the first car 5 on the first track 1 moves toward the storage rack 4, the control system can send an instruction to the first car 5 to make the first car 5 stop outside the corresponding pick-up and placement track section; when the second car 6 completes the pick-up and placement action of the wafer box 7 at the storage rack 4 and exits the storage rack 4, the green light of the corresponding traffic light assembly lights up. At this time, the first car 5 stopped outside the pick-up and placement track section can enter the pick-up and placement track section to take and place the wafer box 7 or pass through the pick-up and placement track section.

[0039] In some embodiments, the length and position of the pick-and-place track segment are adapted to the second track 2. When the first crane 5 is located on the pick-and-place track segment, the first crane 5 can pick up and place the wafer box 7 from the corresponding storage rack 4. This arrangement can ensure that when the second crane 6 is at any position of the second track 2, it will not interfere with the first crane 5 outside the pick-and-place track segment.

[0040] The above control method can effectively avoid the interference of the first crane 5 outside the pick-and-place track section with the second crane 6 when the second crane 6 picks up and places the wafer box 7 from the storage rack 4. However, in actual application, it is possible that when the first crane 5 is on the pick-and-place track section, the second crane 6 picks up and places the wafer box 7 from the storage rack 4. At this time, the traffic light assembly can only warn the first crane 5 outside the pick-and-place track section, while the first crane 5 in the pick-and-place track section may still interfere with the second crane 6. Based on this, in some embodiments, a position information code for the first crane 5 to scan is provided on the pick-and-place track section, and a position information code for the second crane 6 to scan is provided on the second track 2. When the first crane 5 is located on the pick-and-place track section and the second crane 6 needs to pick up and place the wafer box 7 from the corresponding storage rack 4, the control system controls the second crane 6 to avoid the first crane 5 according to the position information codes scanned by the first crane 5 and the second crane 6. Specifically, the position information code on the pick-and-place track segment, the position information code on the second track 2 and the storage position on the storage rack 4 are all set in one-to-one correspondence. It can be understood that the corresponding position information code on the pick-and-place track segment and the position information code on the second track 2 point to the same storage position on the storage rack 4.

[0041] When the control system receives the position information code scanned by the first and second car 5, 6, if the position information code scanned by the second car 6 does not correspond to the position information code scanned by the first car 5 (that is, the first and second car 6 are respectively facing different storage positions), at this time, the picking and placing actions of the first and second car 5 are not interfered with; if the position information code scanned by the second car 6 corresponds to the position information code scanned by the first car 5 (that is, the first and second car 6 are facing the same storage position), the control system controls the second car 6 to move to the remaining position along the second track 2, so that the position information code scanned by the second car 6 does not correspond to the position information code scanned by the first car 5. At this time, the second car 6 and the first car 5 can respectively perform wafer box picking and placing actions on different storage positions on the storage rack 4, and the first and second car 5 will not interfere with each other.

[0042] Through the coordination of the position information code and the control system, while avoiding mutual interference between the first and second car 5, 6, the first car 5 can place the wafer box 7 to be processed on the storage rack 4 while the second car 6 can place the processed wafer box 7 on the storage rack 4 at the same time; when the first car 5 places the wafer box 7 to be processed, the control system can control the first car 5 to move to the storage position where the processed wafer box 7 is placed, while avoiding the second car 6, and then take away the processed wafer box 7 on the storage position; similarly, after the second car 6 places the processed wafer box 7, the control system can control the second car 6 to move to the storage position where the wafer box 7 to be processed is placed, while avoiding the first car 5, and then take away the wafer box 7 to be processed on the storage position.

[0043] In some embodiments, in order to improve the pick-up and placement efficiency of the second car 6, the second car 6 can directly take the wafer box 7 to be processed from the storage rack 4 after placing the processed wafer box 7 on the storage rack 4. After placing the processed wafer box 7, the second gripper 64 can directly take the wafer box 7 to be processed without lateral movement and retraction. Specifically, when the second car 6 places the processed wafer box 7 on the storage rack 4, the second lifting part 62 drives the second transverse movement part 63 and the second grasping part 64 to rise, and then the second car 6 moves along the second track 2 to make the second grasping part 64 move to just above the storage position where the wafer box 7 to be processed is placed (in this process, the second transverse movement part 63 does not drive the second grasping part 64 to move transversely and retract), and then the second lifting part 62 drives the second transverse movement part 63 and the second grasping part 64 to descend to grab the wafer box 7 to be processed, and then the second lifting part 62 drives the second transverse movement part 63 and the second grasping part 64 to rise again, and at the same time, the second transverse movement part 63 drives the second grasping part 64 to move transversely and retract in the direction of the second track 2 to take away the wafer box 7 to be processed on the storage rack 4. That is to say, in the two actions of the second car 6 placing the processed wafer box 7 and taking away the wafer box 7 to be processed, the second transverse moving part 63 only needs to reciprocate transversely once, which further improves the placement efficiency of the second car 6.

[0044] However, since the second gripper 64 does not move laterally and retract after placing the processed wafer box 7, it directly moves to the storage position above the wafer box 7 to be processed, and the second gripper 64 is always located directly above the storage rack 4, it may interfere with the first car 5's pick-up and placement action on the storage rack 4. Therefore, in actual application, if there is no first car 5 on the pick-up and placement track section, after the second car 6 places the processed wafer box 7 on the storage rack 4, the second car 6 can move along the second track 2 to any storage position of the storage rack 4 without the second gripper 64 moving laterally and retracting. If there is a first car 5 on the pick-and-place track section, the control system needs to determine whether the storage position where the second car 6 takes the wafer box 7 to be processed is adjacent to the storage position where the processed wafer box 7 is placed. If they are adjacent, the second car 6 can move to the adjacent storage position where the wafer box 7 to be processed is stored without the second gripping part 64 moving laterally and retracting, and the second gripping part 64 will not interfere with the pick-and-place action of the first car 5; if they are not adjacent, the second gripping part 64 of the second car 6 needs to move laterally and retract after placing the processed wafer box 7, and then move along the second track 2 to the storage position where the wafer box 7 to be processed is stored.

[0045] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A crane system, characterized in that: include A track assembly, the track assembly comprising a first track and a second track arranged in parallel, wherein the second tracks are arranged above the process machine in a one-to-one correspondence; A storage component, the storage component comprising storage racks arranged in one-to-one correspondence with the process machines, each of the storage racks being arranged close to the corresponding process machine and located below the first track; The overhead crane assembly includes a first overhead crane and a second overhead crane. The first overhead crane is located on the first track and is used for transferring wafer boxes between different storage racks. The second overhead crane is located on the second track and is used for transferring wafer boxes between corresponding process machines and storage racks.

2. The overhead travelling vehicle system according to claim 1, characterized in that: The first overhead crane includes a first traveling part, a first lifting part, and a first grasping part. The first traveling part travels along the first track. The first lifting part is installed on the first traveling part and can drive the first grasping part to move up and down. When the first grasping part is located at the highest position of movement, the vertical distance between the first overhead crane and the storage rack is not less than the sum of the heights of the two wafer boxes.

3. The overhead travelling vehicle system according to claim 1, characterized in that: The second car includes a second walking part, a second lifting part, a second transverse moving part, and a second grabbing part. The second walking part moves along the second track. The second lifting part is installed on the second walking part and can drive the second transverse moving part to move up and down. The second grabbing part is installed on the second transverse moving part and can move horizontally toward or away from the first track under the action of the second transverse moving part.

4. The overhead travelling vehicle system according to claim 3, characterized in that: When the second gripping part is at the highest position of movement, the vertical distance between the second carriage and the storage rack is not less than the height of a wafer box, and the vertical distance between the second carriage and the storage rack is less than the sum of the heights of the two wafer boxes.

5. The overhead travelling vehicle system according to claim 1, characterized in that: The height of the second track is lower than that of the first track.

6. The overhead travelling vehicle system according to claim 1, characterized in that: The storage rack is located above the corresponding process machine; and along the length direction of the first track, the storage rack is provided with a plurality of storage positions for placing wafer boxes.

7. A method for controlling an overhead crane system, used for the overhead crane system according to any one of claims 1 to 6, characterized in that: The steps include: Divide the first track into pick-and-place track segments corresponding to the storage racks one by one, and the pick-and-place track segments are located directly above the corresponding storage racks; A traffic light assembly is arranged on the first track in one-to-one correspondence with the storage rack; when the second car takes and places the wafer box on the storage rack, the red light of the traffic light assembly is turned on, and the first car located outside the corresponding take-and-place track section cannot enter the take-and-place track section.

8. The method for controlling an overhead travelling crane system according to claim 7, characterized in that: Position information codes for scanning by the first overhead crane and the second overhead crane are respectively arranged on the pick-and-place track section and the second track; when the first overhead crane is located on the pick-and-place track section and the second overhead crane needs to pick up and place a wafer box from the corresponding storage rack, the control system controls the second overhead crane to avoid the first overhead crane according to the position information codes scanned by the first overhead crane and the second overhead crane.

9. The method for controlling an overhead travelling crane system according to claim 7, characterized in that: The second carriage comprises a second transverse moving part and a second grabbing part, wherein the second grabbing part is mounted on the second transverse moving part and can move horizontally toward or away from the first track under the action of the second transverse moving part; When the second overhead crane picks up and places a wafer box on the storage rack, and the first overhead crane is not on the corresponding pick-up and placement track segment, after the second overhead crane places the processed wafer box on the storage rack, the second overhead crane can move along the second track to any storage position of the storage rack without the second gripping part being retracted laterally.

10. The method for controlling an overhead travelling crane system according to claim 7, characterized in that: The second carriage comprises a second transverse moving part and a second grabbing part, wherein the second grabbing part is mounted on the second transverse moving part and can move horizontally toward or away from the first track under the action of the second transverse moving part; When the second overhead crane picks up and places wafer boxes on the storage rack, and the first overhead crane is on the corresponding pick-up and placement track segment, the control system determines whether the storage position where the second overhead crane places the processed wafer boxes is adjacent to the storage position where the second overhead crane takes the wafer boxes to be processed. If they are adjacent, after the second overhead crane places the processed wafer boxes, the second overhead crane can move along the second track to the adjacent storage position where the wafer boxes to be processed are stored when the second gripping part has not retracted laterally.

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