Exhaust device, exhaust system and wafer processing equipment

Abstract

The utility model provides an exhaust device, an exhaust system and wafer processing equipment. The two ends of the air exhaust device are in fluid connection with a machining cavity of the wafer machining equipment and an air duct outside the wafer machining equipment respectively, and the air exhaust device comprises a first air exhaust pipe, a second air exhaust pipe and a third air exhaust pipe, the branch pipe is arranged at the communicating hole of the first exhaust pipe and is in fluid communication with the first exhaust pipe through the communicating hole, and the branch pipe is configured to be connected with the air pressure detector; and the second exhaust pipe is at least partially nested in the first exhaust pipe, the side wall of the second exhaust pipe at least covers the communicating hole, and a buffer gap is formed between the side wall of the second exhaust pipe and the side wall of the first exhaust pipe at the communicating hole, so that the situation that airflow carries machining dust to impact into the branch pipe is avoided. According to the technical scheme, the airflow speed at the branch pipe is remarkably reduced, vortex is effectively prevented, and dust deposition of the branch pipe and the pressure measuring air pipe is avoided.

Description

Technical Field

[0001] This application relates to the field of wafer processing technology, specifically to an exhaust device, an exhaust system, and wafer processing equipment. Background Technology

[0002] Wafer processing equipment, specifically wafer thinning equipment, is equipped with exhaust ventilation to remove dust floating in the equipment chamber after grinding. To ensure effective dust removal, a certain air pressure is required. Usually, the air pressure of the exhaust duct is monitored by drilling a hole in the side wall of the exhaust duct and connecting a differential pressure transmitter through a pressure measuring air pipe. When the air pressure is insufficient, an alarm will be triggered to remind the staff to carry out maintenance. However, due to the accumulation of dust in the pressure measuring air pipe, false alarms may occur. Utility Model Content

[0003] This application provides an exhaust system and wafer processing equipment to solve or alleviate at least some of the problems in the prior art.

[0004] According to one aspect of this application, an exhaust device is provided for the exhaust system of a wafer processing equipment, wherein the two ends of the exhaust device are respectively fluidly connected to the processing cavity of the wafer processing equipment and an air duct outside the wafer processing equipment, and the exhaust device includes:

[0005] The first row of air ducts has a connecting hole on its side wall;

[0006] A branch pipe is provided at the connecting hole of the first exhaust pipe and is in fluid communication with the first exhaust pipe through the connecting hole; the branch pipe is configured to be connected to the wind pressure detector.

[0007] The second exhaust duct is at least partially nested within the first exhaust duct, and the sidewall of the second exhaust duct at least covers the connecting hole. A buffer gap exists between the sidewall of the second exhaust duct and the sidewall of the first exhaust duct at the connecting hole to prevent airflow carrying processing dust from impacting the branch duct.

[0008] In an optional or preferred embodiment, the sidewall of the second exhaust duct tapers radially inward at the connecting hole to form the buffer gap.

[0009] In an optional or preferred embodiment, the radial dimension of the buffer gap is 5% to 10% of the inner wall radius of the first exhaust duct.

[0010] In an optional or preferred embodiment, the second exhaust duct is provided with an axially extending discharge hole, one end of which is in fluid communication with the buffer gap, and the other end opens toward the air inlet of the exhaust device and is in fluid communication with the collector inside the wafer processing equipment, so as to discharge droplets at the buffer gap.

[0011] In an optional or preferred embodiment, at the outlet of the exhaust device, the first exhaust pipe extends axially beyond the second exhaust pipe.

[0012] In an optional or preferred embodiment, the end of the second exhaust duct facing the air outlet of the exhaust device is constructed with a semi-cylindrical structure, the semi-cylindrical structure covers the connecting hole, and the outer surface of the semi-cylindrical structure is provided with a groove that is recessed away from the connecting hole, and the groove forms the buffer gap with the side wall of the first exhaust duct.

[0013] In an optional or preferred embodiment, the groove extends circumferentially along the outer surface of the semi-cylindrical structure around the axis of the semi-cylindrical structure to communicate with the airflow inside the semi-cylindrical structure.

[0014] In an optional or preferred embodiment, the second exhaust duct is divided into a first section and a second section along the axial direction. The outer diameter of the first section is smaller than the outer diameter of the second section so that the outer contour of the second exhaust duct forms a stepped shape. The first section is closer to the air outlet of the exhaust device than the second section and covers the connecting hole. The buffer gap is formed between the first section and the side wall of the first exhaust duct.

[0015] In an optional or preferred embodiment, the second exhaust pipe includes a separate first pipe segment and a second pipe segment, which are nested into the first exhaust pipe from both ends, and the ends of the first pipe segment and the second pipe segment overlap at the connecting hole to form a fluid-connected labyrinth structure, which forms the buffer gap.

[0016] In an optional or preferred embodiment, the first pipe segment is divided into a first partition and a second partition along the axial direction, the second partition being closer to the connecting hole than the first partition, and the outer diameter of the second partition being smaller than the outer diameter of the first partition.

[0017] The first pipe segment is divided into a third section and a fourth section along the axial direction. The third section is closer to the connecting hole than the fourth section, and the outer diameter of the third section is smaller than the outer diameter of the fourth section. The third section includes a radially spaced double-layer cylindrical structure. The second section is at least partially inserted into the double-layer cylindrical structure to form the labyrinth structure between the second section, the third section, and the sidewall of the first exhaust pipe.

[0018] According to another aspect of this application, an exhaust system for a wafer processing equipment is provided, the exhaust system comprising:

[0019] The exhaust device described above,

[0020] A connecting pipe that fluidly connects the exhaust device to the processing chamber of the wafer processing equipment;

[0021] A wind pressure detector is connected to a branch pipe of the exhaust device to detect the wind pressure in the exhaust device.

[0022] According to another aspect of this application, a wafer processing apparatus is provided, comprising:

[0023] shell;

[0024] A wafer processing unit disposed in the housing, the wafer processing unit including a processing cavity;

[0025] The exhaust system described above has an exhaust device located at the top of the housing, and the connecting pipe of the exhaust system extends upward from the processing chamber to the exhaust device.

[0026] According to the exhaust device, exhaust system, and wafer processing equipment of this application, by setting a double-layer exhaust duct structure and forming a buffer gap between the double-layer exhaust duct structure and at the connecting hole of the branch duct, the airflow speed at the branch duct can be significantly reduced, effectively preventing the generation of eddies, avoiding the accumulation of dust and silicon sludge in the branch duct and pressure measuring air pipe, thus ensuring the detection accuracy of the wind pressure detector, avoiding false alarms, and thus avoiding equipment downtime for maintenance due to false alarms, ensuring the safe and effective operation of the equipment, increasing the effective working time of the equipment, and thereby improving wafer processing efficiency. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0028] Figure 1 A partial schematic diagram of a wafer processing apparatus according to one embodiment of this application is shown;

[0029] Figure 2 A cross-sectional schematic diagram of an exhaust device is shown;

[0030] Figure 3 It shows Figure 2 A schematic diagram of airflow in the exhaust system;

[0031] Figure 4 Show Figure 3 Enlarged view of point A in the middle;

[0032] Figure 5 It shows Figure 1 A schematic diagram of an exhaust device according to one embodiment of this application;

[0033] Figure 6 It shows Figure 5 Cross-sectional view of the exhaust system in the middle;

[0034] Figure 7 It shows Figure 6 A schematic diagram of airflow in the exhaust system;

[0035] Figure 8 It shows Figure 1 A cross-sectional schematic diagram of an exhaust device according to another embodiment of this application;

[0036] Figure 9 It shows Figure 8 A schematic diagram of airflow in the exhaust system;

[0037] Figure 10 It shows Figure 1 A cross-sectional schematic diagram of an exhaust device according to another embodiment of this application;

[0038] Figure 11 It shows Figure 10 A schematic diagram of airflow in the exhaust system.

[0039] Figure label:

[0040] The wafer processing equipment 100 includes a housing 110, a base 120, a wafer processing unit 130, a turntable 131, a support platform 1310, a grinding unit 132, a rough grinding spindle unit 1321, a fine grinding spindle unit 1322, a processing chamber 133, an exhaust device 101, a connecting pipe 102, a connector 103, an exhaust duct 10, a first exhaust duct 1, a second exhaust duct 2, an exhaust hole 200, a semi-cylindrical structure 201, a first pipe section 21, an end of the first pipe section 211, a second pipe section 22, an end of the second pipe section 221, a connecting hole 31, a branch pipe 3, a wind pressure detector 4, a connector 51, a drainage connector 52, a buffer gap G, and a collector 6. Detailed Implementation

[0041] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of this application.

[0042] In the description of this application, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and 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 this application.

[0043] In addition, in the description of this application, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0044] Wafer processing equipment 100, such as wafer thinning equipment, typically includes an exhaust system 101 to remove dust that has been ground and floats within the processing chamber 133 of the equipment. To ensure effective dust removal, the exhaust system 101 needs to achieve a certain air pressure; therefore, the air pressure in the exhaust duct is usually monitored. Figure 1A partial schematic diagram of a wafer processing apparatus 100 according to one embodiment of this application is shown. This apparatus can be used to grind and thin the back side (non-electronic device mounting surface) of a wafer. The apparatus mainly includes a housing 110 (only a portion of the housing 110 is shown in the figure), a base 120 disposed within the housing 110, and a wafer processing unit 130 disposed on the base 120. The wafer processing unit 130 mainly includes a turntable 131, a support stage 1310 disposed on the turntable 131, and a grinding unit 132 disposed above the support stage 1310. The grinding unit 132 may include a rough grinding spindle unit 1321 and a fine grinding spindle unit 1322 as shown in the figure. Multiple support stages 1310 may be disposed on the turntable 131, for example, three (only one is shown in the figure). The support stages 1310 are used to support the wafer. The three carrier platforms 1310 can correspond to three workstations: the rough grinding workstation below the rough grinding spindle unit 1321, the fine grinding workstation below the fine grinding spindle unit 1322, and the loading / unloading workstation shown in the figure. Through the rotation of the turntable 131, the three carrier platforms 1310 can rotate between the three workstations to allow the wafers to be loaded, rough ground, fine ground, and unloaded sequentially. Although not shown, the wafer processing unit 130 may also include a front-end module for providing wafers to be processed and receiving processed wafers, a transfer module for transferring wafers between the front-end module and the wafer processing unit 130, and a cleaning module for cleaning the processed wafers, etc.

[0045] from Figure 1 As can be seen, the grinding wheels at the lower ends of the rough grinding spindle unit 1321 and the fine grinding spindle unit 1322, and the support platform 1310 located below them at the rough grinding and fine grinding stations, are enclosed in the processing cavity 133 to prevent processing dust, such as silicon powder ground off the wafer, from scattering. The wafer processing equipment 100 also includes an exhaust system. The exhaust device 101 of the exhaust system is located at the top of the housing 110. The connecting pipe 102 of the exhaust system extends approximately vertically upward from the processing cavity 133 to the exhaust device 101. The end of the exhaust device 101 facing away from the connecting pipe 102 can be connected to the ventilation system duct of the facility where the wafer processing equipment 100 is located via a connector 103. It should be understood that the exhaust device 101 shown in the figure is located inside the housing 110, but in actual implementation, it may be partially or completely exposed to the outside of the housing 110. The exhaust system may also include a wind pressure detector 4, which may be integrated, for example, into an electrical box above the top wall of the housing 110. The wind pressure detector 4 is connected to a branch pipe 3 of the exhaust unit 101 via a pressure measuring pipe (see...). Figure 2The air pressure in the exhaust device 101 is detected. Only one connecting pipe 102 and one exhaust device 101 near the rough grinding spindle unit 1321 are shown in the figure. In an optional embodiment, the connecting pipe 102 and the exhaust device 101 can be located at the center of the rough grinding spindle unit 1321 and the fine grinding spindle unit 1322. Alternatively, in a preferred embodiment, connecting pipes 102 and exhaust devices 101 can be symmetrically added near the fine grinding spindle unit 1322, so that two sets of connecting pipes 102 and exhaust devices 101 are used for dust discharge at the rough grinding station and the fine grinding station, respectively.

[0046] Figure 2 A cross-sectional schematic diagram of an exhaust device 101 is shown. The exhaust device 101 includes an exhaust duct 10. A connecting hole 31 is provided on the side wall of the exhaust duct 10. A branch pipe 3 is arranged radially outward from the connecting hole 31. A wind pressure detector 4, such as a differential pressure transmitter, is connected through the branch pipe 3 and a connector 51 to detect wind pressure. When the wind pressure is insufficient, the wind pressure detector 4 will sound an alarm to remind the staff to carry out maintenance.

[0047] Figure 3 It shows Figure 2 A schematic diagram of the airflow in the exhaust device 101. Figure 4 for Figure 3 The enlarged view at point A shows the airflow direction indicated by the arrow. It can be seen that the airflow in exhaust duct 10 forms a vortex in branch pipe 3, blowing dust to connector 51 and then into the pressure measuring pipe connecting connector 51 and the air pressure detector 4. The dust in the pressure measuring pipe adheres to the pipe wall. Simultaneously, due to the high humidity and temperature of the gas in processing chamber 133 compared to branch pipe 3, water droplets condense when the airflow reaches branch pipe 3. Over time, these droplets combine with the dust to form silicon sludge, clogging the pressure measuring pipe. This causes the detected air pressure (or airflow pressure) to fall below the set value, resulting in a false alarm from the wafer processing equipment 100, misleading operators into stopping the machine for maintenance.

[0048] Therefore, this application provides an exhaust device 101 for a wafer processing equipment 100, which mainly includes a first exhaust duct 1, a second exhaust duct 2, and a branch duct 3. A connecting hole 31 is provided on the side wall of the first exhaust duct 1. The branch duct 3 is disposed at the connecting hole 31 of the first exhaust duct 1 and is in fluid communication with the first exhaust duct 1 via the connecting hole 31. The branch duct 3 is configured to be connected to a wind pressure detector 4 via a connector 51. The second exhaust duct 2 is at least partially nested within the first exhaust duct 1. The side wall of the second exhaust duct 2 at least covers the connecting hole 31, and a buffer gap G is provided between the side wall of the second exhaust duct 2 and the side wall of the first exhaust duct 1 at the connecting hole 31 to prevent processing dust carried by the airflow from impacting the branch duct 3.

[0049] This application, by setting up a double-layer exhaust duct structure and forming a buffer gap G between the double-layer exhaust duct structure and at the connecting hole 31 of the branch pipe 3, can significantly reduce the airflow speed at the branch pipe 3, effectively prevent the generation of eddies, avoid the accumulation of dust and silica sludge in the branch pipe 3 and the pressure measuring pipe, thus ensuring the detection accuracy of the wind pressure detector, avoiding false alarms, and thus avoiding equipment downtime for maintenance due to false alarms, ensuring the safe and effective operation of the equipment, increasing the effective working time of the equipment, and thereby improving wafer processing efficiency.

[0050] like Figure 5-7 This application illustrates a specific embodiment of an exhaust device 101. One end of the second exhaust pipe 2 faces the outlet of the exhaust device 101 (i.e....). Figure 5 The upper end of the device has a semi-cylindrical structure 201 covering the connecting hole 31. The outer surface of the semi-cylindrical structure 201, facing outwards, has a recessed groove that is radially inwards from the connecting hole 31. The gap between the groove and the side wall of the first exhaust duct forms a buffer gap G. Specifically, the first exhaust duct 1 and the second exhaust duct 2 can be bonded together. At the outlet of the exhaust device 101, the first exhaust duct 1 extends axially beyond the second exhaust duct 2 to save materials and reduce weight while ensuring a buffering effect, and to prevent the second exhaust duct 2 from interfering with the connection between the exhaust device 101 and the factory ventilation system. Figure 5 As shown, the groove extends circumferentially along the outer surface of the semi-cylindrical structure 201 around its axis (the dashed line in the figure) to communicate with the airflow inside the semi-cylindrical structure 201. This ensures that the air pressure at the buffer gap G is consistent with the air pressure inside the semi-cylindrical structure 201. Simultaneously, because the upper part of the second exhaust duct 2 is not completely sealed, liquids such as distilled water carried in the airflow are less likely to accumulate in the buffer gap G. Figure 5 The groove shown extends along a horizontal arc on the outer peripheral surface of the semi-cylindrical structure 201. In an alternative embodiment, it may also extend along a spiral ascending or spiral descending arc on the outer peripheral surface of the semi-cylindrical structure 201.

[0051] In a preferred embodiment, an axially extending discharge hole (not shown, but in fluid communication with the buffer gap G) may also be provided in the second exhaust duct 2. Figure 10 Similar to the discharge port 200 in the example, for instance, one end of the discharge port is configured to open at the lower end face of the groove, and the other end is configured to open at the air inlet of the exhaust device 101, i.e., at the lower end face. The discharge port can be fluidly connected to a collector inside the device (not shown, see reference). Figure 10 For example, a water collection tray can be used so that even if droplets accumulate at the lower end face of the groove, they can be drained away, preventing water accumulation. In a further embodiment, the lower end face of the groove can extend obliquely towards the drain hole, which is more conducive to guiding the liquid flow to the drain hole.

[0052] The exhaust device 101 can prevent the formation of eddies and effectively prevent impurities from entering the branch pipe 3 and the pressure measuring pipe, such as Figure 7 As shown, after adding the second exhaust duct 2, the airflow mainly passes through the exhaust device 101 along the axial direction, and obviously no longer blows into the branch pipe 3. The airflow velocity in the branch pipe 3 is small, or even close to 0, and thus no longer affects the accuracy of the wind pressure detector 4.

[0053] Figure 8-9 An exhaust device 101 according to another specific embodiment of this application is shown. (Compared to...) Figure 5 Similarly, in the embodiment described above, the sidewall of the second exhaust duct 2 radially narrows inward at the connecting hole 31. However, unlike the embodiment, the second exhaust duct 2 does not form the buffer gap G in the form of a groove, but rather in the form of segmented steps. Specifically, the second exhaust duct 2 is axially divided into a first section (in... Figure 8 The middle section is the upper part of the second exhaust duct 2) and the second zone (in Figure 8 The lower part of the second exhaust duct 2 is shown in the image. The outer diameter of the first section is smaller than that of the second section, so that the outer contour of the second exhaust duct 2 forms a stepped shape. The first section is closer to the outlet of the exhaust device 101 than the second section (i.e., the first section is downstream of the second section) and covers the connecting hole 31. A buffer gap G is formed between the first section and the side wall of the first exhaust duct 1. At the outlet of the exhaust device 101, the second exhaust duct 2 extends axially beyond the first exhaust duct 1. The first exhaust duct 1 and the second exhaust duct 2 can also be fixed together by adhesive bonding. This exhaust device 101 can effectively prevent the formation of eddies in the branch pipe 3, and has a simple structure and is easy to manufacture. In a preferred embodiment, an exhaust hole (not shown, connected to the buffer gap G) is provided axially in the second section. Figure 10 Similar to the drain hole 200 in the previous embodiment, the drain hole may be fluidly connected to a collector inside the device, such as a water collection tray, to prevent grinding chips or droplets from accumulating on the end face of the second region facing the buffer gap G. In a further embodiment, the end face of the second region facing the buffer gap G may extend obliquely toward the drain hole, thereby further facilitating the guidance of liquid flow toward the drain hole.

[0054] Figure 10-11The following diagram illustrates another specific embodiment of the exhaust device 101 of this application. The second exhaust duct 2 comprises a separate first pipe segment 21 and a second pipe segment 22. The first pipe segment 21 and the second pipe segment 22 are nested into the first exhaust duct 1 from both ends, and the ends 211 and 221 of the first pipe segment 21 and the second pipe segment 22 facing each other overlap at the connecting hole 31, forming a fluid-connected labyrinth structure that forms a buffer gap G. The first exhaust duct 1 can be bonded together with the first pipe segment 21 and the second pipe segment 22. One of the first pipe segments 21 and the second pipe segment 22, near the air inlet of the exhaust device 101 (e.g., the lower second pipe segment 22), may also be provided with a discharge hole 200. The discharge hole 200 is connected to a drain connector 52 for drainage. The discharge hole 200 can be connected to a collector 6 inside the device, such as a water collection tray, via the drain connector 52, a drain pipe (not shown), etc. (shown only in boxes in the figure). It should be understood that even if a small amount of gas blows in from the exhaust port 200, it will have little impact on the differential pressure transmitter. This structure prevents the formation of eddies, effectively preventing processing dust from entering the pressure measuring gas pipe, and can also discharge droplets condensed in the buffer gap G, even in relatively humid environments. Figure 11 As can be seen, after adding the second exhaust duct 2, which includes the first duct section 21 and the second duct section 22, the airflow no longer blows into the branch duct 3, effectively preventing the formation of eddies in the branch duct 3 and avoiding the accumulation of dust in the branch duct 3 and the pressure measuring tube of the wind pressure detector.

[0055] More specifically, the first pipe segment 21 is divided into a first section and a second section along the axial direction. The second section is closer to the connecting hole 31 than the first section, and the outer diameter of the second section is smaller than the outer diameter of the first section, so that the outer contour of the second pipe segment 21 is stepped. The second section is, for example,... Figure 10 The first pipe segment 211 has its upper portion as the first partition. The second pipe segment 22 is axially divided into a third partition and a fourth partition. The third partition is closer to the connecting hole 31 than the fourth partition, and the outer diameter of the third partition is smaller than that of the fourth partition. The third partition is, for example,... Figure 10 The second pipe section 221, and the fourth section is the portion below the third section. The third section may include a radially spaced double-layered cylindrical structure. Figure 10 The inner layer of the double-layer cylindrical structure shown is longer than the outer layer. In optional embodiments, the inner layer may be of uniform length or shorter than the outer layer. The second section is at least partially inserted into the double-layer cylindrical structure to form a curved, extending labyrinth structure between the second section, the third section, and the sidewalls of the first exhaust duct. In optional embodiments, the second and third sections may have other structures to make the labyrinth structure simpler or more complex; for example, the second section may be a double-layer cylindrical structure, and the third section may be a triple-layer cylindrical structure accordingly.

[0056] In a preferred embodiment, the radial dimension of the buffer gap G is 5% to 10% of the inner wall radius of the first exhaust duct 1. For example, the inner wall radius of the first exhaust duct 1 is 45 mm, and the outer wall radius of the second exhaust duct 2 at the connection hole 31 is 42 mm. Thus, the radial dimension of the buffer gap G is 3 mm, which is 6.7% of the inner wall radius of the first exhaust duct 1. The above-mentioned size range of the buffer gap G can ensure an effective buffering effect while avoiding excessive reduction of the cross-sectional area of ​​the internal airflow channel of the exhaust device 101 due to the setting of the second exhaust duct 2 and the buffer gap G, thereby ensuring smooth and efficient exhaust.

[0057] The above embodiments are only used to illustrate the embodiments of this application, and are not intended to limit the embodiments of this application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of this application. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of this application, and the patent protection scope of the embodiments of this application should be defined by the claims.

Claims

1. An exhaust device for the exhaust system of wafer processing equipment, characterized in that, The exhaust device is fluidly connected at both ends to the processing cavity of the wafer processing equipment and the air duct outside the wafer processing equipment, respectively. The exhaust device includes: The first row of air ducts has a connecting hole on its side wall; A branch pipe is provided at the connecting hole of the first exhaust pipe and is in fluid communication with the first exhaust pipe through the connecting hole; the branch pipe is configured to be connected to the wind pressure detector. The second exhaust duct is at least partially nested within the first exhaust duct, and the sidewall of the second exhaust duct at least covers the connecting hole. A buffer gap exists between the sidewall of the second exhaust duct and the sidewall of the first exhaust duct at the connecting hole to prevent airflow carrying processing dust from impacting the branch duct.

2. The exhaust device according to claim 1, characterized in that, The sidewall of the second exhaust duct contracts radially inward at the connecting hole to form the buffer gap.

3. The exhaust device according to claim 1, characterized in that, The radial dimension of the buffer gap is 5% to 10% of the inner wall radius of the first exhaust duct.

4. The exhaust device according to claim 1, characterized in that, The second exhaust duct is provided with an axially extending discharge hole. One end of the discharge hole is in fluid communication with the buffer gap, and the other end opens toward the air inlet of the exhaust device and is in fluid communication with the collector inside the wafer processing equipment to discharge droplets at the buffer gap.

5. The exhaust device according to claim 1, characterized in that, At the air outlet of the exhaust device, the first exhaust pipe extends axially beyond the second exhaust pipe.

6. The exhaust device according to any one of claims 1-5, characterized in that, The second exhaust duct has a semi-cylindrical structure at one end facing the air outlet of the exhaust device. The semi-cylindrical structure covers the connecting hole, and a groove is provided on the outer surface of the semi-cylindrical structure that is recessed away from the connecting hole. The groove and the side wall of the first exhaust duct form the buffer gap.

7. The exhaust device according to claim 6, characterized in that, The groove extends circumferentially along the outer surface of the semi-cylindrical structure around the axis of the semi-cylindrical structure to communicate with the airflow inside the semi-cylindrical structure.

8. The exhaust device according to any one of claims 1-5, characterized in that, The second exhaust duct is divided into a first section and a second section along the axial direction. The outer diameter of the first section is smaller than that of the second section so that the outer contour of the second exhaust duct forms a stepped shape. The first section is closer to the air outlet of the exhaust device than the second section and covers the connecting hole. The buffer gap is formed between the first section and the side wall of the first exhaust duct.

9. The exhaust device according to any one of claims 1-4, characterized in that, The second exhaust duct includes a separate first section and a second section. The first section and the second section are nested into the first exhaust duct from both ends, and the ends of the first section and the second section overlap at the connecting hole to form a fluid-connected labyrinth structure, which forms the buffer gap.

10. The exhaust device according to claim 9, characterized in that, The first pipe segment is divided into a first section and a second section along the axial direction. The second section is closer to the connecting hole than the first section, and the outer diameter of the second section is smaller than the outer diameter of the first section. The second pipe segment is axially divided into a third section and a fourth section, the third section being closer to the connecting hole than the fourth section, and the outer diameter of the third section being smaller than the outer diameter of the fourth section; the third section includes a radially spaced double-layer cylindrical structure, the second section being at least partially inserted into the double-layer cylindrical structure to form the labyrinth structure between the second section, the third section, and the sidewall of the first exhaust pipe.

11. An exhaust system for a wafer processing equipment, characterized in that, The exhaust system includes: The exhaust device according to any one of claims 1-10; A connecting pipe that fluidly connects the exhaust device to the processing chamber of the wafer processing equipment; A wind pressure detector is connected to a branch pipe of the exhaust device to detect the wind pressure in the exhaust device.

12. A wafer processing equipment, characterized in that, include: shell; A wafer processing unit disposed in the housing, the wafer processing unit including a processing cavity; According to claim 11, the exhaust device of the exhaust system is disposed at the top of the housing, and the connecting pipe of the exhaust system extends upward from the processing chamber to the exhaust device.

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