A dust removal device for wafer cassette overhead buffer station

Abstract

This invention discloses a dust removal device for an overhead buffer station in a wafer cassette, comprising a base frame, an outwardly extending support arm on the outer side of the long side of the base frame, several support columns on the base frame, and an upper frame at the top of each support column away from the base frame; a pair of matching linear guides on both sides of the long side of the base frame, a motor mount on each corresponding linear guide, and sliders matching the linear guides on the bottom of each side of the motor mount, the sliders being slidably engaged on the linear guides; the outer end of the motor mount protruding beyond the linear guides; a stepper motor on the motor mount, with a lead screw parallel to the linear guides, the two ends of the lead screw being mounted on the base frame; a rotary servo motor on the outer end of the motor mount protruding beyond the linear guides, a pair of rotary servos symmetrically mounted at both ends of the motor mount. This application utilizes the rotary servos to rotate the dust removal head 180 degrees, thereby avoiding the support arms on the base frame.

Description

Technical Field

[0001] This invention relates to the field of dust removal equipment technology, and in particular to a dust removal device for a wafer cassette overhead buffer station in the semiconductor industry. Background Technology

[0002] A wafer is a silicon chip used in the fabrication of silicon semiconductor integrated circuits. During semiconductor manufacturing, wafers are placed in wafer cassettes and then transported by overhead cranes to an aerial buffer station in the workshop. The aerial buffer station is equipped with storage carriers 91 (buffers, transfer tracks), and these carriers 91 have several wafer cassette storage areas 93. (See appendix) Figure 7 As shown, in a semiconductor chip manufacturing workshop, the wafer cassette storage area 93 on the storage carrier 91 is equipped with several distributed positioning support heads 92. These are designed to prevent the wafer cassettes from contacting the surface of the storage carrier 91 (cache, turnaround track). The bottom surface of the wafer cassette rests on the positioning support heads 92, maintaining a distance between the bottom surface and the surface of the storage carrier 91. During prolonged use, the wafer cassette storage area 93 generates ultrafine dust, affecting the yield of wafer products. To maintain the cleanliness of the wafer cassette storage area 93, it needs to be cleaned regularly. Existing cleaning methods rely on manual cleaning. Since the wafer cassette storage area 93 (storage carrier 91: cache, turnaround track) is mostly located at the top of the production area and is numerous, manual cleaning requires climbing ladders to reach the top storage area, which is extremely inconvenient and necessitates a temporary interruption of production. The cleaning process is time-consuming, easily disturbs the dust to other environments, and makes it impossible to control the cleanliness level. Manual cleaning involves contact and carries the risk of scratching storage areas and generating static electricity. Summary of the Invention

[0003] In order to solve the problems existing in the prior art, the purpose of this invention is to provide a dust removal device for an overhead buffer station of semiconductor wafer cassettes, which uses a non-contact dust removal head for cleaning, and uses mechanical motion to replace manual cleaning motion, thereby realizing automated cleaning of the wafer cassette storage area.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A dust removal device for a wafer cassette overhead buffer station includes a base frame, an outwardly extending support arm on the outer side of the long side of the base frame, a plurality of support columns on the base frame, and an upper frame on the top of the support columns away from the base frame; a pair of matching linear guide rails are provided on both sides of the long side of the base frame, a motor base is mounted on the corresponding linear guide rails on both sides, and sliders matching the linear guide rails are provided on the bottom of both sides of the motor base, the sliders are slidably locked on the linear guide rails, and the outer end of the motor base extends outward from the outside of the linear guide rails;

[0006] A stepper motor is mounted on the motor base, and a lead screw parallel to the linear guide rail is mounted in the stepper motor. The two ends of the lead screw are mounted on the bottom frame.

[0007] A rotary servo is provided on the outer end of the motor base that protrudes from the outer side of the linear guide rail. A pair of rotary servos are symmetrically arranged at both ends of the motor base. A rotating head is provided at the bottom of the outer end of the rotary servo away from the motor base. A dust removal head is provided on the side of the rotary servo. A rotating connecting plate that matches the rotating head is provided on the dust removal head. The rotating head is fixedly connected to the rotating connecting plate. The rotating connecting plate protrudes from the outer side of the dust removal head.

[0008] The dust collector head is equipped with an exhaust duct, the bottom of which is a negative pressure chamber, inside which is a positive pressure chamber, and above which is a fan chamber. A through-hole is provided between the positive pressure chamber and the fan chamber.

[0009] Furthermore, in some embodiments, a high-efficiency filter is provided on the upper frame, a negative pressure intake port is provided on one side of the high-efficiency filter, a negative pressure fan is provided on the other side of the high-efficiency filter, and a negative pressure fan exhaust port is provided at the end of the negative pressure fan away from the negative pressure intake port.

[0010] The exhaust duct is connected to the negative pressure chamber; the exhaust duct is connected to the negative pressure inlet through a duct.

[0011] Furthermore, in some embodiments, a gap is provided between the inner wall of the negative pressure chamber and the outer wall of the positive pressure chamber; a suction slit is provided on the bottom surface of the gap between the inner wall of the negative pressure chamber and the outer wall of the positive pressure chamber.

[0012] The bottom of the positive pressure chamber has a dust blowing gap; a positive pressure fan is installed inside the fan chamber, and an air inlet is installed on the positive pressure fan, which is located on the top of the fan chamber.

[0013] Furthermore, in some embodiments, the motor base is provided with a chain frame, which is fixedly connected to the motor base, and the motor base is mounted on the linear guide rail by a slider; the outer end of the motor base extends and protrudes outward from the long side of the bottom frame.

[0014] The chain frame is equipped with a drag chain, with the end of the drag chain away from the chain frame set on the upper frame; a middle horizontal plate is provided above the chain frame, and a clearance groove is provided on the middle horizontal plate to accommodate the drag chain.

[0015] Furthermore, in some embodiments, a motor driver is provided on the middle horizontal plate, and the motor driver is electrically connected to the stepper motor; a dust cover is provided on the motor base cover, and the chain frame is located outside the dust cover; a transport crane clamping top cover is provided on the upper frame.

[0016] A displacement sensor is located below the middle horizontal plate, and a battery is located on the upper frame.

[0017] Furthermore, in some embodiments, suction gaps are provided around the bottom surface of the empty space between the inner wall of the negative pressure chamber and the outer wall of the positive pressure chamber.

[0018] The bottom surface of the positive pressure chamber has an I-shaped dust blowing gap.

[0019] Furthermore, in some embodiments, the bottom corner of the fan cavity near the positive pressure chamber is embedded into the top corner of the adjacent side of the positive pressure chamber, and the portion of the bottom corner of the fan cavity embedded into the top corner of the positive pressure chamber forms an embedded cavity;

[0020] An air outlet is provided on the embedded cavity, which is connected to the positive pressure chamber. The positive pressure chamber is connected to the fan cavity through the air outlet.

[0021] This application utilizes a positive pressure fan to generate a positive pressure airflow, which is blown out through the dust-blowing gaps. Dust-laden airflow drawn in through the suction gaps enters a high-efficiency filter via a negative pressure inlet, and the filtered clean air is discharged from the negative pressure fan's exhaust outlet. This application employs a lead screw and stepper motor for linear movement; a rotary servo motor rotates the dust removal head 180 degrees, thus avoiding the support arms on the base frame. During cleaning, the dust removal head rotates to bypass the support arms on both sides of the base frame.

[0022] This application employs a non-contact, suspended positive and negative air duct cleaning method. The OHB (overhead crane transport system) uses a transport crane to hold the top cover, moving the dust removal device to the wafer cassette storage area requiring cleaning. The dust removal device (cleaning device) achieves air-electric isolation and independent operation, improving product processing stability and yield. It can effectively replace manual cleaning, improve work efficiency, and does not interrupt the production rhythm. It can automatically clean approximately 91.7% of the area of ​​the wafer cassette overhead buffer station. Attached Figure Description

[0023] Figure 1 This is a perspective view of an embodiment of this application;

[0024] Figure 2 This is a cross-sectional schematic diagram of an embodiment of this application;

[0025] Figure 3 This is a structural diagram of an embodiment of this application;

[0026] Figure 4 This is an assembly diagram of an embodiment of this application;

[0027] Figure 5 This is a cross-sectional schematic diagram of the dust removal head portion in an embodiment of this application;

[0028] Figure 6 for Figure 5 Structural schematic diagrams of the A1, A2, and A3 sections of the central dust collector head;

[0029] Figure 7This is a schematic diagram illustrating the application of an embodiment of this application;

[0030] Figure 8 This is a schematic diagram of the rotation of the dust removal head in an embodiment of this application.

[0031] Figure label:

[0032] 11. Base frame, 12. Support column, 13. Upper frame, 14. Linear guide rail, 15. Cable chain, 16. Support arm, 18. High-efficiency filter, 19. Negative pressure fan, 21. Negative pressure suction inlet, 22. Middle cross plate, 23. Lead screw, 24. Chain frame, 25. Stepper motor, 26. Displacement sensor, 27. Motor driver, 28. Clearance groove, 29. Motor base, 31. Rotary servo motor, 32. Rotary head, 33. Negative pressure fan exhaust outlet, 34. Dust cover, 35. Slider, 37. Top cover for transport crane clamping. 39. Battery, 41. Dust removal head, 42. Exhaust duct, 43. Air inlet duct, 44. Negative pressure chamber, 45. Negative pressure lateral expansion chamber, 46. Fan chamber, 47. Embedded chamber, 48. Air outlet, 49. Bottom surface of the machine cavity, 51. Positive pressure chamber, 52. Positive pressure top surface, 53. Suction gap, 54. Dust blowing gap, 55. Rotating connecting plate, 56. Positive pressure fan, 57. Outer positive pressure chamber wall, 58. Support arm, 59. Positioning slot, 91. Storage carrier, 92. Positioning support head, 93. Wafer box storage area. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0034] In the description of this invention, it should be noted that the terms "lateral," "upper," "lower," "front," "rear," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0035] This application is used for dust removal from wafer cassette overhead buffer stations in the semiconductor industry. A storage carrier 91 in a semiconductor chip manufacturing workshop has several wafer cassette storage areas 93. The surface of the storage carrier 91 has several positioning support heads 92, meaning the surface of the wafer cassette storage area 93 has several positioning support heads 92. The bottom surface of the wafer cassette rests on the positioning support heads 92, which prevent the bottom surface of the wafer cassette from contacting the surface of the storage carrier 91 when the wafer cassette is placed in the wafer cassette storage area 93. To prevent the dust removal device of this application from contacting the surface of the storage carrier 91 (buffer, turnover track), the bottom frame 11 of the dust removal device of this application has support arms 58 that match and correspond to the positioning support heads 92 on the surface of the storage carrier 91. The support arms 58 are located on the outer side of the long side of the bottom frame 11 and extend outwards, meaning the outer side of the long side of the bottom frame 11 has outwardly protruding support arms 58. A dust removal head 41 is provided on the bottom frame 11, located on the storage carrier 91 (buffer, turnover track).

[0036] Furthermore, in one embodiment, the bottom surface of the support arm 58 is provided with a positioning groove 59 that matches the positioning support head 92, so that the positioning groove 59 of the support arm 58 (bottom frame 11) abuts against the positioning support head 92 of the storage carrier 91. After the positioning groove 59 abuts against the positioning support head 92, the support arm 58 is suspended and bears the weight, maintaining the distance between the dust removal device of this application and the surface of the storage carrier 91 without contact, allowing the dust removal head 41 to perform cleaning in a non-contact, suspended position on the storage carrier 91 (buffer, turnover track). However, the support arm 58 (short beam) on the bottom frame 11 is suspended and covers the track of the wafer cassette storage area 93, which hinders the movement of the dust removal head 41 on the storage carrier 91 (track).

[0037] Referring to the accompanying drawings, the present invention includes a base frame 11, on which a plurality of support columns 12 are provided. Preferably, the support columns 12 are located at the four corners of the base frame 11, and an upper frame 13 is provided at the top of the support columns 12 away from the base frame 11. A pair of matching linear guide rails 14 are provided on the long sides of both sides of the base frame 11. A motor base 29 is mounted on the corresponding linear guide rails 14 on both sides. The bottom of both sides of the motor base 29 is provided with sliders 35 that match the linear guide rails 14. The sliders 35 are slidably engaged on the linear guide rails 14. The motor base 29 is mounted on the linear guide rails 14 through the sliders 35, and the outer end of the motor base 29 extends and protrudes outward from the linear guide rail 14.

[0038] Furthermore, in one embodiment, a stepper motor 25 is mounted on the motor mount 29. The stepper motor 25 has a lead screw 23 parallel to the linear guide rail 14, with both ends of the lead screw 23 mounted on the base frame 11. A chain frame 24 is mounted on the motor mount 29 and is fixedly connected to the motor mount 29; alternatively, the stepper motor 25 can also have a chain frame 24 fixedly connected to it, both being equivalent technical solutions.

[0039] Furthermore, in one embodiment, a drag chain 15 is provided on the chain frame 24, with one end of the drag chain 15 away from the chain frame 24 disposed on the upper frame 13. Furthermore, a middle horizontal plate 22 is provided above the chain frame 24, and a clearance groove 28 is formed on the middle horizontal plate 22 to accommodate the passage of the drag chain 15. A motor driver 27 is provided on the middle horizontal plate 22, and the motor driver 27 is electrically connected to the stepper motor 25. A dust cover 34 is provided on the motor base 29, and the chain frame 24 is disposed outside the dust cover 34.

[0040] A rotary servo motor 31 is provided at the outer end of the motor base 29, which protrudes from the outer side of the linear guide rail 14. A rotary head 32 is provided at the bottom of the outer end of the rotary servo motor 31 away from the motor base 29. A dust removal head 41 is provided on the side of the rotary servo motor 31. A rotary connecting plate 55 corresponding to the rotary head 32 is provided on the dust removal head 41. The rotary head 32 is fixedly connected to the rotary connecting plate 55, which protrudes from the outer side of the dust removal head 41. The rotary head 32 drives the dust removal head 41 to rotate 180° through the rotary connecting plate 55.

[0041] The upper frame 13 is equipped with a transport crane clamping top cover 37.

[0042] See appendix Figure 6 As shown, Figure 6 for Figure 5 Structural schematic diagrams of the A1-direction cross-section (planar view), A2-direction cross-section (planar view), and A3-direction cross-section (planar view) of the central dust collector head 41, attached. Figure 6 The document details the specific structure of the dust collector head 41. The dust collector head 41 is equipped with an exhaust duct 42, the exhaust duct 42 opening vertically upwards, and a negative pressure chamber 44 at the bottom of the exhaust duct 42, which is connected to the negative pressure chamber 44. A positive pressure chamber 51 is located within the negative pressure chamber 44. A gap (separation gap) is provided between the inner wall of the negative pressure chamber 44 and the outer wall of the positive pressure chamber 51. A suction slit 53 is provided at the bottom of the gap (separation gap) between the inner wall of the negative pressure chamber 44 and the outer wall of the positive pressure chamber 51, isolating the negative pressure chamber 44 from the positive pressure chamber 51. Preferably, suction slits 53 are provided around the bottom of the gap (separation gap) between the inner wall of the negative pressure chamber 44 and the outer wall of the positive pressure chamber 51. A dust blowing slit 54 is provided at the bottom of the positive pressure chamber 51; more preferably, an I-shaped dust blowing slit 54 is provided at the bottom of the positive pressure chamber 51.

[0043] Furthermore, in one embodiment, a fan chamber 46 is provided on the upper part of the positive pressure chamber 51, and a through air outlet 48 is provided between the positive pressure chamber 51 and the fan chamber 46. The fan chamber 46 is located on the side of the exhaust duct 42. The bottom corner (bottom) of the fan chamber 46 near the positive pressure chamber 51 is embedded (extended) into the top corner (top) of the adjacent side of the positive pressure chamber 51, and the portion of the bottom corner of the fan chamber 46 embedded (extended) into the top corner of the positive pressure chamber 51 forms an embedded cavity 47. Furthermore, with the attached... Figure 5Taking an example, the bottom corner of the fan cavity 46 near the exhaust duct 42 extends into (embeds) the top corner (top) of the adjacent side of the positive pressure chamber 51 to form an embedded cavity 47. The positive pressure top surface 52 of the positive pressure chamber 51 is higher than the bottom surface 49 of the fan cavity 46, and the positive pressure top surface 52 and the bottom surface 49 overlap in the longitudinal direction (longitudinal intersection distance). The outer positive pressure cavity wall 57 of the positive pressure chamber 51 protrudes outward and extends into the bottom surface 49 of the fan cavity 46, and the portion of the outer positive pressure cavity wall 57 extending into the bottom surface 49 overlaps in the transverse direction (transverse intersection distance). In other words, the height of the embedded cavity 47 is the distance by which the positive pressure top surface 52 is higher than the bottom surface 49 (overlap height), and the width of the embedded cavity 47 is the distance by which the outer positive pressure cavity wall 57 extends into the bottom surface 49 (overlap width).

[0044] An air outlet 48 is provided on the embedded cavity 47, and the air outlet 48 is connected through the positive pressure chamber 51; that is, the positive pressure chamber 51 is connected through the air outlet 48 to the fan cavity 46.

[0045] A positive pressure fan 56 is installed in the fan chamber 46, and an air inlet duct 43 (positive pressure fan inlet) is installed on the positive pressure fan 56. The air inlet duct 43 is located on the fan chamber 46. The positive pressure fan 56 is integrated into the dust collector head 41 through the air outlet 48 structure embedded in the cavity 47.

[0046] The negative pressure chamber 44 has an outwardly protruding negative pressure lateral expansion chamber 45 on the side near the fan chamber 46. The negative pressure lateral expansion chamber 45 is used to increase the volume of the negative pressure chamber 44 and avoid the narrowing bottleneck at the air outlet 48. The negative pressure lateral expansion chamber 45 is located below the bottom surface 49 of the fan chamber, and there is a gap (separation gap) between the negative pressure lateral expansion chamber 45 and the bottom surface 49 of the fan chamber to expand the air cavity. The lower part of the negative pressure chamber 44 below the negative pressure lateral expansion chamber 45 is recessed near the outer positive pressure chamber wall 57. The recessed space at the lower part of the negative pressure chamber 44 near the outer positive pressure chamber wall 57 and from the negative pressure lateral expansion chamber 45 forms a rotation avoidance space.

[0047] Furthermore, in one embodiment, a high-efficiency filter 18 is provided on the upper frame 13. A negative pressure intake port 21 is provided on one side of the high-efficiency filter 18, and a negative pressure fan 19 is provided on the other side. A negative pressure fan exhaust port 33 is provided at the end of the negative pressure fan 19 furthest from the negative pressure intake port 21. The exhaust duct 42 is connected to the negative pressure intake port 21 via a conduit. The sequence of negative pressure intake port 21 → high-efficiency filter 18 → negative pressure fan 19 → negative pressure fan exhaust port 33 constitutes a high-efficiency negative pressure filtration mechanism (prior art disclosed by the applicant), which needs no further explanation.

[0048] A displacement sensor 26 is located below the middle horizontal plate 22, and a battery 39 is located on the upper frame 13.

[0049] The dust removal equipment described in this application can be transported to the corresponding wafer cassette storage area 93 via an OHB (overhead crane system). Upon receiving a signal, the equipment will activate and perform dust removal on the wafer cassette storage area 93 (track). Once one wafer cassette storage area 93 is cleaned, it will move to the next wafer cassette storage area 93 via the OHB overhead crane system. Through the scheduling of the overhead crane system, all wafer cassette storage areas 93 in the production plant will be dusted.

[0050] The dust removal equipment of this application adopts a non-contact dust removal head 41. Dust is blown up by positive pressure and then collected by negative pressure. The dust-laden air is filtered through a high-efficiency filter 18, and clean gas is discharged through the negative pressure fan exhaust port 33. Its dust removal efficiency for 0.3μm particle size dust can reach over 85%. The equipment motor base 29 has non-contact dust removal heads 41 at both ends. A stepper motor 25 (screw motor) drives the dust removal head 41 to move linearly, and a rotary servo motor 31 rotates the dust removal head 41, effectively extending the coverage area of ​​the dust removal head 41 and bypassing the support arms 58 (support beams) on both sides of the base frame 11. This allows the wafer cassette overhead buffer station to achieve a cleaning area of ​​91.7%, resulting in excellent dust removal performance. However, since the wafer cassette overhead buffer station is located at the top of the factory area, manual wiping requires the use of a ladder, making the wiping process complex. Cleaning the two wafer cassette storage areas 93 may take more than half an hour. Production needs to be interrupted during manual wiping, and manual climbing poses safety risks. Using the equipment described in this application, dust removal of a wafer storage area 93 takes approximately 2 minutes. The dust removal process does not require interruption of production, significantly saving cleaning time and greatly increasing efficiency. The dust removal equipment is transported via an overhead crane system, eliminating the need for manual transport and avoiding the safety risks associated with manual climbing. The equipment is powered by a 39-cell battery, requiring no external power supply, reducing the difficulty of moving it across multiple areas. Using 24V low-voltage electricity effectively ensures the safety of manual operation. The equipment weight is controlled below 11kg, and its dimensions meet the existing design requirements of overhead crane transport systems, making it compatible with current overhead crane transport systems on the market.

[0051] This equipment includes modules such as a rotary servo motor 31 (rotating component), a stepper motor 25 with a lead screw 23 (linear motion module), and a high-efficiency filter 18 (dust removal filter component).

[0052] Rotary servo motor 31 and rotating head 32: Rotational motion is achieved by using rotary servo motor 31. Its rated rotational torque reaches 20 kgf.cm. Rotary servo motor 31 is equipped with a magnetic encoder, which can automatically correct itself through the program if the position is incorrect during operation, avoiding collisions or manual operation that could cause inaccurate positioning of dust removal head 41. It can complete the action in 2 seconds and can meet the rotational function of dust removal head 41 (avoiding support arm 58).

[0053] Stepper motor 25 and lead screw 23 (linear motion module): A linear motion module is formed by combining a through-type stepper motor 25 and a lead screw 23 with a double-type linear guide rail 14. The stepper motor 25 can provide a thrust of 140N, which can overcome the resistance brought by the telescopic pipe, and the linear guide rail 14 and slider 35 stabilize the overall movement. The repeatability of the stepper motor 25 (lead screw motor) can reach ±0.03mm. Compared with traditional ordinary motors, the through-type stepper motor 25 (lead screw motor) can achieve a longer stroke on both sides, which is suitable for maximizing the travel distance of the dust removal head 41 and covering a larger dust removal area in a limited space.

[0054] The dust removal and filtration module includes an ultrasonic dust removal head 41, a positive pressure fan 56, a negative pressure fan 19, and a negative pressure high-efficiency filter 18. The high-efficiency filter 18 is equipped with the negative pressure fan 19 and a negative pressure inlet 21, which is connected to the exhaust duct 42 of the ultrasonic dust removal head 41 via a flexible hose. Innovatively, the positive pressure fan 56 and the ultrasonic dust removal device are integrated into a single module, eliminating the need for connecting conduits for the positive pressure fan 56.

[0055] The overall dimensions of the equipment are controlled within 388×355.5×338mm, and the weight is controlled below 11kg. It operates on DC24V and is composed of an aluminum alloy frame and carbon fiber end caps to ensure the overall frame strength and lightweight design. The top cover 37 is designed according to the lifting dimensions of the overhead crane. Inside, there is a dust removal high-efficiency filter chamber that can be equipped with two high-efficiency filters 18, which can respectively handle the dust absorbed by the dust removal modules on both sides.

[0056] The dust removal mechanism includes a dust removal head 41, with a frame sealing cover at the top of the dust removal head 41 cavity; a positive pressure chamber 51 is provided inside the dust removal head 41 cavity, with a separation gap between the top of the positive pressure chamber 51 and the top of the negative pressure chamber 44 inside the dust removal head 41 cavity; and a positive pressure fan 56 is installed above the positive pressure chamber 51.

[0057] Furthermore, in some embodiments, there is a gap between the outer wall of the positive pressure chamber 51 and the inner wall of the dust removal head 41 cavity, and the cavity between the inner wall of the dust removal head 41 cavity and the outer wall of the positive pressure chamber 51 forms a negative pressure chamber 44, which is disposed in the dust removal head 41 cavity.

[0058] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A dust removal device for an overhead buffer station of a wafer cassette, comprising a base frame (11), wherein an outwardly extending support arm (58) is provided on the outer side of the long side of the base frame (11), and a plurality of support columns (12) are provided on the base frame (11), wherein an upper frame (13) is provided at the top of the support columns (12) away from the base frame (11); characterized in that, The bottom frame (11) has a pair of matching linear guide rails (14) on both sides of the long side. A motor seat (29) is mounted on the corresponding linear guide rails (14) on both sides. The bottom of the motor seat (29) on both sides is provided with a slider (35) that matches the linear guide rail (14). The slider (35) is slidably locked on the linear guide rail (14). The outer end of the motor seat (29) extends out of the outside of the linear guide rail (14). A stepper motor (25) is provided on the motor base (29), and a lead screw (23) parallel to the linear guide rail (14) is provided in the stepper motor (25). The two ends of the lead screw (23) are set on the bottom frame (11). A rotary servo motor (31) is provided on the outer end of the motor base (29) protruding from the outer side of the linear guide rail (14). A pair of rotary servo motors (31) are symmetrically arranged at both ends of the motor base (29). A rotary head (32) is provided at the bottom of the outer end of the rotary servo motor (31) away from the motor base (29). A dust removal head (41) is provided on the side of the rotary servo motor (31). A rotary connecting plate (55) matching the rotary head (32) is provided on the dust removal head (41). The rotary head (32) is fixedly connected to the rotary connecting plate (55). The rotary connecting plate (55) protrudes out from the outer side of the dust removal head (41). The dust removal head (41) is equipped with an exhaust duct (42), the bottom of the exhaust duct (42) is equipped with a negative pressure chamber (44), the cavity of the negative pressure chamber (44) is equipped with a positive pressure chamber (51), the top of the positive pressure chamber (51) is equipped with a fan chamber (46), and a through air outlet (48) is opened between the positive pressure chamber (51) and the fan chamber (46).

2. The dust removal device for an overhead buffer station of a wafer cassette according to claim 1, characterized in that, The upper frame (13) is provided with a high-efficiency filter (18), a negative pressure inlet (21) is provided on one side of the high-efficiency filter (18), a negative pressure fan (19) is provided on the other side of the high-efficiency filter (18), and a negative pressure fan exhaust port (33) is provided at the end of the negative pressure fan (19) away from the negative pressure inlet (21). The exhaust duct (42) is connected to the negative pressure chamber (44); the exhaust duct (42) is connected to the negative pressure inlet (21) through a conduit.

3. A dust removal device for an overhead buffer station of a wafer cassette according to claim 2, characterized in that, A gap is provided between the inner wall of the negative pressure chamber (44) and the outer wall of the positive pressure chamber (51); a suction gap (53) is provided on the bottom surface of the gap between the inner wall of the negative pressure chamber (44) and the outer wall of the positive pressure chamber (51). The bottom surface of the positive pressure chamber (51) is provided with a dust blowing gap (54); a positive pressure fan (56) is provided in the fan cavity (46), and an air inlet duct (43) is provided on the positive pressure fan (56), which is located on the fan cavity (46).

4. A dust removal device for an overhead buffer station of a wafer cassette according to claim 1, characterized in that, The motor base (29) is provided with a chain frame (24), which is fixedly connected to the motor base (29). The motor base (29) is mounted on the linear guide rail (14) via a slider (35). The outer end of the motor base (29) extends outward from the long side of the bottom frame (11). A drag chain (15) is provided on the chain frame (24), and the end of the drag chain (15) away from the chain frame (24) is set on the upper frame (13); a middle horizontal plate (22) is provided above the chain frame (24), and a clearance groove (28) is provided on the middle horizontal plate (22) to accommodate the drag chain (15) to pass through.

5. A dust removal device for an overhead buffer station of a wafer cassette according to claim 4, characterized in that, The middle horizontal plate (22) is provided with a motor driver (27), which is electrically connected to a stepper motor (25); the motor base (29) is covered with a dust cover (34), and the chain frame (24) is located outside the dust cover (34); the upper frame (13) is provided with a transport crane clamping top cover (37). A displacement sensor (26) is provided under the middle horizontal plate (22), and a battery (39) is provided on the upper frame (13).

6. A dust removal device for an overhead buffer station of a wafer cassette according to claim 2, characterized in that, Suction gaps (53) are provided around the bottom surface of the empty space between the inner wall of the negative pressure chamber (44) and the outer wall of the positive pressure chamber (51). The bottom surface of the positive pressure chamber (51) has an I-shaped dust blowing slit (54).

7. A dust removal device for an overhead buffer station of a wafer cassette according to claim 3, characterized in that, The bottom corner of the fan cavity (46) near the positive pressure chamber (51) is embedded into the top corner of the adjacent side of the positive pressure chamber (51), and the part of the bottom corner of the fan cavity (46) embedded into the top corner of the positive pressure chamber (51) forms an embedded cavity (47). An air outlet (48) is provided on the embedded cavity (47), and the air outlet (48) is connected to the positive pressure chamber (51). The positive pressure chamber (51) is connected to the fan cavity (46) through the air outlet (48).

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