Slewing device suitable for wafer defect detection

Abstract

The invention belongs to the technical field of wafer detection, and discloses a slewing device suitable for wafer defect detection, which comprises a shell, a vacuum chuck, a rotating shaft, a driving piece, a limiting assembly and an adjusting assembly. At least one end of the shell is open; the vacuum chuck is rotationally connected to one end of the shell and is used for adsorbing a to-be-detected wafer; the rotating shaft penetrates through the shell, and one end of the rotating shaft is connected with the vacuum chuck; the driving piece is arranged in the shell and is in transmission connection with the other end of the rotating shaft; the limiting assembly is used for preventing the rotating shaft from moving in the shell in the radial direction and the axial direction. The adjusting assembly is arranged on the shell and used for adjusting the mass eccentricity of the rotating device. The rotary device has high load capacity, can sensitively change speed under the load working condition, guarantees the dynamic rigidity of a system, is excellent in vibration performance and strict in bounce limitation on parts, can achieve the national standard level G0.4 in dynamic balance level, and can meet the operation stability of the device at a high rotating speed.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer detection, and in particular to a rotating device suitable for wafer defect detection. Background Art

[0002] The wafer motion trajectories used in the current mainstream wafer defect detection instruments are linear reciprocating scanning and spiral scanning. The spiral scanning method requires that the wafer motion trajectory meet the established requirements of non-equidistant spiral lines, whose pitch is not fixed and the average value is small (usually only tens of microns). The spiral motion is generally achieved through a two-axis motion system consisting of a linear motion system and a high-speed rotary system.

[0003] Based on the measurement requirements of wafer defect detection, the requirements for high-speed rotary systems are also relatively high. Existing rotary platforms often adopt a flat design, but this design makes the system itself have a large moment of inertia and the system's load capacity is weak. Summary of the invention

[0004] The object of the present invention is to provide a rotary device suitable for wafer defect detection, which adopts a slender design and meets the requirements of high rotation speed, high torque, high positioning accuracy, high rigidity, and high-speed vacuum adsorption stability.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A rotary device suitable for wafer defect detection comprises: an outer shell, which is hollow and has at least one end open; a vacuum suction cup, rotatably connected to one end of the outer shell and used for adsorbing a wafer to be detected; a rotating shaft, which passes through the outer shell and one end of the rotating shaft is connected to the vacuum suction cup; a driving member, which is arranged in the outer shell and is transmission-connected to the other end of the rotating shaft; a limit assembly, which is used to limit the displacement of the rotating shaft along its radial and axial directions inside the outer shell; and an adjusting assembly, which is arranged in the outer shell and used for adjusting the mass eccentricity of the rotary device.

[0007] Preferably, the limit assembly includes: a radial limit bearing, arranged inside the outer shell and located in the circumference of the rotating shaft, for preventing the rotating shaft from displacing in its radial direction; an axial limit bearing, arranged inside the outer shell and located at one end of the rotating shaft, for preventing the rotating shaft from displacing in its axial direction.

[0008] Preferably, an extension shaft is provided at one end of the rotating shaft connected to the driving member and extending axially along the outer shell, a flange is provided on the outer periphery of the extension shaft, and the axial limit bearing limits the rotating shaft by limiting the axial position of the flange.

[0009] Preferably, at least two groups of radial limit bearings are provided, which are spaced apart along the axial direction of the rotating shaft and sleeved on the rotating shaft.

[0010] Preferably, a sleeve is arranged between two groups of the radial limit bearings to support two adjacent groups of the radial limit bearings arranged at intervals, and the sleeve is in contact with the inner wall of the outer shell.

[0011] Preferably, an air flotation air path is provided on the outer shell, and the air flotation air path is used to supply air to the radial limit bearing; wherein, the air flotation air path includes an air flotation air inlet and an air flotation air hole, the air flotation air inlet is arranged on the outer shell, the air flotation air hole is arranged inside the side wall of the outer shell and extends along the axial direction of the outer shell, and the air flotation air hole is respectively connected to the air flotation air inlet and the radial limit bearing.

[0012] Preferably, a vacuum air path is provided on the outer shell and the rotating shaft, and the vacuum suction cup generates negative pressure through the vacuum air path; wherein, the vacuum air path includes a connecting hole, a vacuum chamber and a vacuum interface, the vacuum chamber is provided between the outer shell and the rotating shaft, the connecting hole is provided in the rotating shaft and is connected to the vacuum suction cup at one end and connected to the vacuum chamber at the other end, and the vacuum interface passes through the side wall of the outer shell and is connected to the vacuum chamber.

[0013] Preferably, a sealing member is further included, and a plurality of sealing members are provided for sealing gaps between the structures.

[0014] Preferably, a position sensor is further included, which is located inside the housing and arranged at the bottom of the driving member.

[0015] Preferably, the outer wall of the housing corresponding to the driving member has a plurality of protrusion structures.

[0016] Beneficial effects of the present invention:

[0017] The rotary device for wafer defect detection of the present invention comprises a housing, a vacuum suction cup, a rotating shaft, a driving member, a limit assembly and an adjusting member. The vacuum suction cup is rotatably connected to one end of the housing and is used to absorb the wafer to be detected; the rotating shaft is arranged in the housing, and one end of the vacuum suction cup is connected to the vacuum suction cup; the driving member is arranged in the housing and is connected to the other end of the rotating shaft; the limit assembly is used to prevent the displacement of the rotating shaft in the radial and axial directions inside the housing; the adjusting member is arranged in the housing and is used to adjust the mass eccentricity of the rotary device. Each structure of the present invention is designed to be slender along the axial direction of the rotating shaft, so that the rotational inertia of the device itself can be controlled to be smaller, the load capacity is greatly enhanced, the requirement for the rotational inertia of the vacuum suction cup is lower, and the speed can be sensitively changed under load conditions; the dynamic rigidity of the system is ensured by the setting of the limit assembly, so that the vibration performance of the device is excellent and the jump limit of the parts is strict; the mass eccentricity of the rotary device is adjusted in combination with the adjusting member, so that the dynamic balance level of the device can finally reach the highest level of the national standard G0.4, so as to meet the stability of the device operation at high speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of the three-dimensional structure of a rotary device in one embodiment of the present invention;

[0019] Figure 2 is a cross-sectional schematic diagram of a rotary device in one embodiment of the present invention;

[0020] Figure 3 is a schematic cross-sectional view of a vacuum interface in one embodiment of the present invention;

[0021] Figure 4 is an exploded schematic diagram of one end of a rotary device in one embodiment of the present invention;

[0022] Figure 5 It is an exploded schematic diagram of the other end of the rotary device in one embodiment of the present invention.

[0023] In the figure:

[0024] 1. Shell; 11. Cylinder; 12. Base; 121. Bottom plate; 13. Connector; 14. Air flotation vent; 15. Upper cover plate; 16. Lower cover plate; 17. Side plate; 18. Support plate;

[0025] 2. Vacuum suction cup;

[0026] 3. Rotating shaft; 31. Connecting hole;

[0027] 4. Driving member; 41. Outer ring stator; 42. Inner ring rotor;

[0028] 51. Radial limit bearing; 52. Axial limit bearing;

[0029] 6. Adjustment assembly; 7. Extension shaft; 8. Air flotation inlet; 9. Vacuum interface;

[0030] 10. Limit screw; 20. Sleeve; 30. Position sensor; 40. Vacuum chamber; 50. Accommodation chamber; 60. Power aviation socket; 70. DB9 communication cable. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0032] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0035] The present invention discloses a rotating device suitable for wafer defect detection, such as Figure 1 and Figure 2As shown, it includes a housing 1, a vacuum suction cup 2, a rotating shaft 3, a driving member 4, a limit assembly and an adjustment assembly 6. The housing 1 is hollow and has at least one end open. The housing 1 is generally cylindrical. In some embodiments, as Figure 2 and Figure 5 As shown, the housing 1 includes a cylinder 11 and a base 12. Both ends of the cylinder 11 are open, one end of the cylinder 11 is sealed by the base 12, and the cylinder 11 and the base 12 are detachably connected. Optionally, the housing 1 also includes a connector 13 between the cylinder 11 and the base 12. The base 12 and the cylinder 11 are connected by the connector 13, which is convenient for adapting to the situation where the diameters of the base 12 and the cylinder 11 are inconsistent, and it is convenient to replace different types of bases 12 for connection with an external workbench, thereby enhancing the applicability of the rotary device. Figure 2 and Figure 4 As shown, the vacuum suction cup 2 is rotatably connected to one end of the housing 1 for adsorbing the wafer to be tested. In some embodiments, the vacuum suction cup 2 is rotatably connected to the housing 1 through a rotating shaft 3; the rotating shaft 3 is arranged through the housing 1, and one end of the rotating shaft 3 is connected to the vacuum suction cup 2. Optionally, the diameter of the end of the rotating shaft 3 connected to the vacuum suction cup 2 is set larger than the diameter of the main shaft body, so that the installation of the rotating shaft 3 and the vacuum suction cup 2 is more stable; in other embodiments, a mounting flange can also be set at one end of the rotating shaft 3 connected to the vacuum suction cup 2, and the rotating shaft 3 is connected to the vacuum suction cup 2 through the mounting flange. The driving member 4 is arranged in the housing 1 and is transmission-connected to the other end of the rotating shaft 3; the limit assembly is used to prevent the displacement of the rotating shaft 3 along its radial and axial directions inside the housing 1; the adjusting assembly 6 is arranged in the housing 1, and is used to adjust the mass eccentricity of the rotary device. It can be understood that the above-mentioned structure is slender along the axial design of the rotating shaft 3. Compared with the flat design of conventional rotating devices or platforms, the rotational inertia of the device itself can be controlled to be smaller, which greatly enhances the load capacity of the system and has lower requirements on the rotational inertia of the vacuum suction cup 2, so that the rotating device has a higher torque, thereby enabling the vacuum suction cup 2 to quickly accelerate and decelerate under load conditions, thereby improving the measurement efficiency.

[0036] Since the size of the wafer defect itself is generally very small (generally nanometer level), the vibration and jitter of the high-speed rotating system will have a great impact on the accuracy of defect detection and the positioning accuracy of the defect position. Therefore, the dynamic rigidity requirements of the high-speed rotating system itself are very high, and the vibration performance and the beating of the components must be limited to a very high level, and the dynamic balance level must reach the highest national standard level G0.4. To this end, in some embodiments, the limit assembly includes a radial limit bearing 51 and an axial limit bearing 52. The radial limit bearing 51 is arranged inside the housing 1 and is located in the circumference of the rotating shaft 3 to prevent the rotating shaft 3 from moving in its radial direction; the axial limit bearing 52 is arranged inside the housing 1 and is located at one end of the rotating shaft 3 to prevent the rotating shaft 3 from moving in its axial direction. It can be understood that by simultaneously limiting the radial and axial positions of the rotating shaft 3, the rigidity of the rotating shaft 3 structure and the stability of the device operation are guaranteed.

[0037] In some embodiments, Figure 2 and Figure 5 As shown, an extension shaft 7 is provided at one end of the rotating shaft 3 connected to the driving member 4 along the axial extension of the housing 1, and a flange is provided on the outer periphery of the extension shaft 7. The axial limit bearing 52 limits the rotating shaft 3 by the axial position of the limit flange. The extension shaft 7 and the rotating shaft 3 can be an integrally formed whole or two detachably connected parts. For example, the extension shaft 7 in this embodiment is provided at one end of the rotating shaft 3 and is detachably connected to the rotating shaft 3 by a fixing screw. In some specific embodiments, the axial limit bearing 52 includes a thrust roller bearing, which is used to limit the axial displacement of the rotating shaft 3. Specifically, the thrust roller bearings are respectively arranged on both sides of the flange of the extension shaft 7, so as to prevent the axial displacement of the rotating shaft 3 without affecting the normal rotation of the rotating shaft 3. It can be understood that by setting the axial limit bearing 52, the axial rigidity of the rotating device is improved; preferably, the thrust roller bearing has an allowable speed range of 5000rpm-14000rpm. Optionally, the axial limit bearing 52 is selected to allow a maximum speed of 14000rpm, which meets the use requirement of 4000rpm and avoids the thrust roller bearing from reaching the maximum load to extend its service life. Of course, according to actual needs, a bearing model that allows a higher speed can also be used; similarly, the axial load that the thrust roller bearing can withstand is required to be at least 40kN.

[0038] In some embodiments, Figure 2As shown, at least two groups of radial limit bearings 51 are provided, which are spaced apart along the axial direction of the rotating shaft 3 and sleeved on the rotating shaft 3. The radial limit bearings 51 are sleeved on the rotating shaft 3 to limit the radial displacement of the rotating shaft 3. Each group of radial limit bearings 51 is provided with two and used in pairs. At least two groups of radial limit bearings 51 are spaced apart along the axial direction of the rotating shaft 3. It can be understood that by providing the radial limit bearings 51 and the use of the above-mentioned radial limit bearings 51, the radial rigidity of the high-speed rotary system can be guaranteed. In some specific embodiments, the radial limit bearing 51 uses a pair of angular contact ball bearings or a pair of tapered roller bearings installed back to back, which can limit the axial displacement of the rotating shaft 3 while further enhancing the axial rigidity of the device structure; optionally, the allowable speed range of the radial limit bearing 51 needs to be 5000rpm-12000rpm, and optionally, the radial limit bearing 51 is selected to allow a maximum speed of 12000rpm to meet the use requirement of 4000rpm; of course, the present invention takes the use requirements of some embodiments as an example to illustrate, and according to actual needs, a bearing model that allows a higher speed can also be used; similarly, the radial limit bearing 51 can withstand a radial load of at least 20kN.

[0039] In some embodiments, the housing 1 is further provided with an air flotation path, which is used to supply air to the radial limit bearing 51; wherein the air flotation path includes an air flotation air inlet 8 and an air flotation air hole 14, such as Figure 2 As shown, the air flotation air inlet 8 is arranged on the housing 1, the air flotation air hole 14 is arranged inside the side wall of the housing 1 and is extended along the axial direction of the housing 1, the air flotation air hole 14 is respectively connected to the air flotation air inlet 8 and the air inlet of the radial limit bearing 51, the air flotation air inlet 8 is connected to the external air source, and compressed air is introduced into the radial limit bearing 51 through the air flotation air path, so that a very thin compressed air film layer is formed between the two groups of paired radial limit bearings 51 and the housing 1, which can not only increase the bearing capacity of the bearing, but also adjust the dynamic comprehensive damping of the radial limit bearing 51, and further enhance the dynamic rigidity of the device structure. In order to cooperate with the setting of the air flotation air path, the radial limit bearing 51 is selected with rubber end caps on both sides to ensure air tightness; in other embodiments, the radial limit bearing 51 can also be directly set as an air flotation bearing or a combination of an air flotation bearing and the above-mentioned angular contact ball bearing or tapered roller bearing.

[0040] Since the wafer needs to be fixed on the rotary device through vacuum adsorption, the vacuum air path of the rotary device needs to be designed. At a speed of more than 4000rpm, most of the current rotary joints (or air slip rings) either cannot meet the ultra-high speed requirements or cannot guarantee long-term service life. Therefore, the vacuum air path design of high-speed rotary devices requires a certain degree of difficulty.

[0041] In order to solve the problems of difficult vacuum air path design and short service life, the rotary device of the present invention is provided with a vacuum air path on the housing 1 and the rotating shaft 3, and the vacuum suction cup 2 generates negative pressure through the vacuum air path; wherein the vacuum air path includes a connecting hole 31, a vacuum cavity 40 and a vacuum interface 9, wherein the vacuum cavity 40 is arranged between the housing 1 and the rotating shaft 3, the connecting hole 31 is arranged in the rotating shaft 3 and is connected to the vacuum suction cup 2 at one end and connected to the vacuum cavity 40 at the other end, wherein the connecting hole 31 is arranged along the central axis of the rotating shaft 3, and the vacuum interface 9 is arranged through the side wall of the housing 1 and is connected to the vacuum cavity 40. In some specific embodiments, a plurality of openings for realizing the connection between the connecting hole 31 and the vacuum cavity 40 are evenly spaced along the circumference of the rotating shaft 3, and optionally, the number of the openings is 4, and the diameter of the openings is smaller than the diameter of the connecting hole 31, which can ensure the connectivity between the connecting hole 31 and the vacuum cavity 40 when the rotating shaft 3 rotates, and can also ensure the structural rigidity of the rotating shaft 3. It is understandable that the design of the vacuum air circuit of the present invention avoids the use of rotary joints or air slip rings, which is equivalent to building an air-supported air slip ring, which can ensure air tightness under ultra-high-speed conditions. Under the premise that the structure does not fail, the vacuum air circuit has a nearly unlimited service life; in terms of air tightness design, it can avoid the use of dynamic sealing O-rings, and only static sealing O-rings and radial bearings with sealing covers are required to meet the use requirements of ultra-high-speed dynamic seals. In some embodiments, the vacuum interface 9 and the air flotation air inlet 8 are both configured as quick plugs, which are convenient for connection to an external air source, and the quick plug is sealed to the housing 1. The vacuum air intake is VAC (vacuum / negative pressure suction gas), and the air flotation air intake is CDA (compressed dry air).

[0042] To facilitate the structural sealing arrangement and the installation of the radial limit bearing 51, in some embodiments, as Figure 2 and Figure 3As shown, a sleeve 20 is arranged between two groups of radial limit bearings 51 to support the two adjacent groups of radial limit bearings 51 arranged at intervals, and the sleeve 20 is fitted with the inner wall of the shell 1. The sleeve 20 is arranged in the vacuum chamber 40, and the sleeve 20 is fitted with the inner wall of the shell 1. The vacuum interface 9 is arranged through the sleeve 20. Along the circumference of the shell 1, limit screws 10 are also arranged on both sides of the vacuum interface 9 to limit the installation angle of the sleeve 20 and prevent the sleeve 20 from rotating along its axial direction to ensure the smoothness of the vacuum air path. Specifically, taking the radial limit bearings 51 as an example, the two groups of radial limit bearings 51 are respectively arranged at the two ends of the sleeve 20, and the sleeve 20 plays a role in supporting and spacing the two groups of radial limit bearings 51, and is also the installation base of the seal of the vacuum chamber 40; there are multiple seals in the rotary device, which are used to seal the gaps between the structures. Specifically, seals are provided at multiple locations in the rotary device that need to be sealed. For example, seals are provided between the two end faces of the sleeve 20 and the two sets of radial limit bearings 51. The sleeve 20 serves as a mounting base for the seal. Grooves are provided on the two end faces of the sleeve 20 for limiting the seal. The seal here is provided as an O-ring to ensure the sealing of the vacuum air path. A seal is provided between the peripheral side of the connecting hole 31 at the connection between the rotating shaft 3 and the vacuum suction cup 2 and the vacuum suction cup 2. At least one of the two adjacent end faces of the vacuum suction cup 2 and the rotating shaft 3 is provided with a groove for limiting the seal. The depth of the groove is less than the thickness of the seal.

[0043] The measurement process of a single wafer requires the turntable to rotate a large number of times. In order to ensure the measurement efficiency, a rotating device with a speed exceeding 4000rpm is generally required to meet the measurement efficiency requirements, and the speed uniformity must be high, generally not exceeding 1%; therefore, the drive member 4 of the present invention adopts a frameless high-speed motor, which is a hollow high-speed rotating motor, including an outer ring stator 41 and an inner ring rotor 42, and its speed can reach more than 4000rpm, meeting the system speed requirements; the peak torque exceeds 2N·m, and the comprehensive damping does not exceed 0.1N·m, ensuring that the system can accelerate from static to the maximum speed within 2s. Among them, the outer ring stator 41 is fixedly connected to the inner wall of the shell 1, and the inner ring rotor 42 is fixed on the rotating shaft 3. It can be understood that the material of the shell 1 is generally selected from aviation aluminum alloy, which can not only ensure high strength, high rigidity, and light weight, but also can quickly conduct the heat generated during the operation of the frameless high-speed motor, and the inner cylindrical surface of the shell 1 that is in direct contact with the frameless high-speed motor must be conductively oxidized to ensure that the frameless high-speed motor and the shell 1 of the rotating device are well grounded.

[0044] Since wafer defect detection requires the precise location of wafer defects, the high-speed rotary system has a high requirement for rotary positioning accuracy. Considering the high-speed rotary working conditions, the position sensor 30 has a higher performance requirement to meet this requirement. The position sensor 30 of the present invention is located inside the housing 1 and is close to the drive member 4. Specifically, Figure 2 As shown, a housing cavity 50 is provided between the cylinder 11 and the base 12 of the housing 1, an opening is provided on one side of the housing cavity 50, and a side plate 17 is provided at the opening, and the side plate 17 is used to seal the housing cavity 50. A support plate 18 is provided between the housing cavity 50 and the cylinder 11, and the support plate 18 is annularly provided, and the support plate 18 is detachably connected to the end face of the cylinder 11, and the support plate 18 is used to fix and support the frameless high-speed motor, and the position sensor 30 is provided in the housing cavity 50 and is located at the bottom of the frameless high-speed motor. Among them, the position sensor 30 is a position feedback sensor of the rotary device, which can output the current angle position signal of the rotary device in real time, and its resolution generally needs to reach 2^16bit or more, which can be realized by using devices such as Hall sensors, circular gratings, optical encoders, magnetic encoders, and rotary transformers. It can be understood that designing both the frameless high-speed motor and the position sensor 30 in a closed cavity can improve the electromagnetic compatibility and anti-interference ability of the system, and ensure that the performance of the frameless high-speed motor and the position sensor 30 is fully and stably exerted.

[0045] In some embodiments, Figure 1 As shown, the rotary device also includes a power aviation socket 60 and a DB9 communication line 70. The power aviation socket 60 is a power supply socket for the high-speed rotary system, which is connected to the power supply line of the frameless high-speed motor and an external 220V power supply; the DB9 communication line 70 is a communication line for the rotary device, and is connected to the power supply line and communication line of the position sensor 30 at the same time. The DB9 communication line 70 is externally connected to the drive control system of the rotary device to feed back the position signal of the position sensor 30.

[0046] In some embodiments, Figure 2 and Figure 4 As shown, an upper cover plate 15 is provided at one end of the cylinder 11 of the housing 1 close to the vacuum suction cup 2. The upper cover plate 15 is annular, and the center of the annular plate is used to allow the rotating shaft 3 to pass through. The upper cover plate 15 is covered on the end face of the housing 1 and fixed to the housing 1, serving as an axial fixing member for the radial limit bearing 51 and the sleeve 20. A lower cover plate 16 is provided at one end of the base 12 of the housing 1 away from the cylinder 11. The lower cover plate 16 is annular, and the center of the annular plate is used to avoid the extension shaft 7. The lower cover plate 16 is covered on the base 12 and fixed to the base 12, serving as an axial fixing member for the axial limit bearing 52. Optionally, as Figure 2 and Figure 5 As shown, a bottom plate 121 is further provided at the bottom of the base 12 , and the bottom plate 121 is detachably connected to the base 12 , so as to facilitate the installation and maintenance of the structure in the base 12 .

[0047] In some embodiments, the outer wall of the housing 1 corresponding to the driving member 4 has a plurality of protrusions, and the plurality of protrusions are evenly and spaced apart along the axial direction of the housing 1, so that the outer wall of the housing 1 is arranged in a corrugated shape. Optionally, as Figure 2 and Figure 5 As shown, the adjustment component 6 is arranged between two adjacent protrusion structures and located inside the side wall of the housing 1. It can be understood that the corrugated housing 1 can greatly increase the first-order natural frequency of the system and improve the dynamic stability of the system, and can also increase the heat dissipation area to ensure the heat dissipation efficiency of the high-speed motor.

[0048] In some embodiments, the adjustment assembly 6 includes a plurality of adjustment screws, and a plurality of threaded holes are evenly and spaced apart along the circumference of the side wall of the housing 1, and an adjustment screw is screwed into each threaded hole. It is understandable that by adjusting the screw-in depth of each adjustment screw, the mass eccentricity of the high-speed rotary device can be accurately adjusted, thereby adjusting its dynamic balance level to an ideal state. Optionally, the threaded holes and adjustment screws are both set to 12, and after adjustment, the positions of the 12 adjustment screws are locked with thread glue.

[0049] The installation and adjustment method of the rotary device applicable to wafer defect detection of the present invention is roughly as follows:

[0050] First, epoxy structural glue (metal particle conductive glue) is evenly applied on the outer surface of the outer ring stator 41 of the frameless high-speed motor, and then the outer ring stator 41 is smoothly pushed into the interior of the cylinder 11 of the shell 1 along the end of the cylinder 11 of the shell 1 close to the base 12 to ensure that the outer ring stator 41 is firmly fixed to the shell 1 and well grounded.

[0051] After the outer ring stator 41 is installed in place, the support plate 18 is installed and the outer ring stator 41 is pressed. The support plate 18 can be installed on the cylinder 11 of the outer shell 1 by screws arranged along the circumference of the outer shell 1, and the pre-tightening force of the screws at each location must be uniform; optionally, the support plate 18 and the outer shell 1 are fixedly connected by 12 screws.

[0052] Then, a polyester film of suitable thickness is installed in the inner bore of the outer ring stator 41 to ensure the clearance and concentricity of the inner and outer rings of the frameless high-speed motor, and then the inner ring rotor 42 of the frameless high-speed motor is smoothly pushed into the inner ring of the polyester film. After the inner ring rotor 42 is installed, the polyester film is removed, and the running clearance is checked for any debris or blockage, and the inner ring rotor 42 is rotated by hand to confirm that it can rotate freely; then the position sensor 30 is installed at the bottom of the frameless high-speed motor.

[0053] The first set of paired radial limit bearings 51, sleeve 20, and the second set of paired radial limit bearings 51 are pushed into the outer shell 1 from the other end of the cylinder 11 of the outer shell 1 in sequence, and are pressed with the upper cover plate 15. Two seals are installed at both ends of the sleeve 20, and the seals can be O-rings, and the installation angle of the sleeve 20 is fixed with the limit screws 10 on both sides. The limit screws 10 and the outer shell 1 are sealed, for example, silicone rubber is applied to ensure air tightness. The upper cover plate 15 is fixed to the end face of the outer shell 1 by multiple screws. Optionally, the screws and threaded holes between the upper cover plate 15 and the end face of the outer shell 1 are set at 6 locations and evenly distributed along the circumference of the outer shell 1. It should be noted that the pre-tightening force of the screws at each location of the upper cover plate 15 must be uniform, and the combined pre-tightening force ensures that the two seals have a suitable amount of compression. In order to ensure the air tightness of the vacuum air path, the compression is generally controlled at about 15%.

[0054] Pass the power supply line of the frameless high-speed motor through the installation hole of the power supply aviation socket 60 in the housing 1, weld the power supply line to the corresponding pins of the power supply aviation socket 60, and install the heat shrink sleeve. Then install the power supply aviation socket 60 on the housing 1. The length of the wire harness must be controlled to prevent the length of the wire harness inside the housing 1 from being too long or too short; then cover the power supply line and communication line of the position sensor 30 with a heat shrink sleeve and reserve a suitable length.

[0055] Push the rotating shaft 3 into the housing 1 from the end of the cylinder 11 of the housing 1 away from the base 12, respectively install the radial bearings and the frameless high-speed motor in two places, install the base 12, and optionally install the fastening screws of the cylinder 11 and the base 12 and the connecting piece 13. And pass the power supply line and communication line of the position sensor 30 through the corresponding installation holes of the base 12.

[0056] Install a set of axial limit bearings 52 into the base 12, and then install the extension shaft 7 on the rotating shaft 3, and ensure the concentricity of the two. At this time, it is necessary to ensure that the extension shaft 7 and the axial limit bearing fit tightly. If they do not fit tightly, the extension shaft 7 needs to be precisely trimmed until it meets the requirements.

[0057] The second set of axial limit bearings 52 are installed into the base 12 and pressed with the lower cover plate 16. The lower cover plate 16 and the base 12 are fixed by a plurality of screws. Optionally, six screws and threaded holes are provided between the lower cover plate 16 and the base 12 and are evenly distributed along the circumference of the lower cover plate 16. It is necessary to ensure that the pre-tightening force of the screws at each location of the lower cover plate 16 is uniform.

[0058] The bottom plate 121 is mounted on the base 12 , and the power supply line and the communication line of the position sensor 30 are welded to the connector of the DB9 communication line 70 , and then the side plate 17 is mounted on the housing 1 to seal the accommodating cavity 50 .

[0059] Sequentially install the seal at the vacuum suction cup 2 and the vacuum suction cup 2 on the rotating shaft 3. The seal can be an O-ring to ensure that the screw preload between the vacuum suction cup 2 and the rotating shaft 3 is uniform, and the combined preload ensures that the O-ring has a suitable compression amount. To ensure the airtightness of the vacuum air path, the compression amount is generally controlled at about 15%. Optionally, the vacuum suction cup 2 is fixedly connected to the rotating shaft 3 by three screws.

[0060] Two quick plugs serving as the vacuum interface 9 and the air flotation inlet 8 are mounted on the housing 1 to ensure air tightness.

[0061] In order to ensure that the rotary device has higher dynamic rigidity and smaller comprehensive damping, the rotary device is ventilated using the quick plug of the air floatation air inlet 8, so that an extremely thin compressed air film layer is formed between the two paired radial bearings and the housing 1, which can not only increase the bearing capacity of the bearing, but also adjust the dynamic comprehensive damping of the bearing.

[0062] Check whether the eccentricity of the slewing device meets the requirements. If not, fine-tune the system eccentricity by adjusting the screwing depth of the 12 adjusting screws in the housing 1 until the dynamic balance level of the system is improved to meet the requirements.

[0063] It should be noted that the sequence and installation method of the above-mentioned installation and adjustment method of the rotary device are only preferred embodiments, and the actual installation and adjustment method are not limited thereto.

[0064] The rotary device suitable for wafer defect detection of the present invention utilizes a frameless high-speed motor equipped with a position sensor to realize high-speed rotation and high-speed angle feedback of the system, thereby saving the installation space of the encoder of the conventional rotary system. By selecting a slender high-speed motor, the high-speed rotary system is designed to be slender as a whole. Compared with the flat type of the conventional rotary system, the rotational inertia of the system itself can be controlled to be smaller, which greatly enhances the load-carrying capacity of the system and reduces the requirement for the rotational inertia of the vacuum suction cup. The dynamic rigidity of the system is ensured by the design of the thrust roller bearing of the radial limit bearing and the axial limit bearing. The dynamic rigidity of the system is further enhanced by passing compressed air through the radial limit bearing.

[0065] The present invention also avoids the use of rotary joints or air slip rings through the design of the vacuum air circuit, which is equivalent to building an air-supported air slip ring, which can not only ensure air tightness under ultra-high-speed conditions but also have an unlimited lifespan; in the air tightness design, the use of dynamic sealing O-rings is avoided, and only static sealing O-rings and radial bearings with sealing covers are required to meet the use requirements of ultra-high-speed dynamic seals; the motor and sensor of the rotary device are designed in a closed cavity, which improves the electromagnetic compatibility and anti-interference ability of the system.

[0066] The present invention also adopts a corrugated design for the shell, which can greatly increase the first-order natural frequency of the system and improve the dynamic stability of the system on the one hand; on the other hand, it can increase the heat dissipation area and ensure the heat dissipation efficiency of the high-speed motor. At the same time, since the selected frameless high-speed motor itself has low power, it avoids the dependence of conventional high-speed motor heat dissipation on water cooling or air cooling, and simplifies the use conditions of the system; the dynamic balance level of the system is fine-tuned by adjusting the depth of screw insertion at multiple places, the adjustment method is simple, the adjustment accuracy is high, and the dynamic balance level of the device reaches the highest level of the national standard G0.4, so as to meet the stability of the device operation at high speed.

[0067] Compared with the conventional flat rotary system, which can only be installed externally through flanges, the high-speed rotary device of the present invention has a more flexible external mechanical interface, which can be fixed by hugging the cylindrical surface or by adding flanges to the outer shell. The first fixing method is more conducive to reducing the overall space and weight of the system, and is more conducive to compact and lightweight design.

[0068] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A rotating device suitable for wafer defect detection, characterized in that: include: The housing (1) is hollow; A vacuum suction cup (2) rotatably connected to one end of the housing (1) and used for sucking the wafer to be inspected; A rotating shaft (3) is inserted through the housing (1), and one end of the rotating shaft (3) is connected to the vacuum suction cup (2); A driving member (4) is disposed in the housing (1) and is drivingly connected to the other end of the rotating shaft (3); A limiting assembly, the limiting assembly being used to limit the displacement of the rotating shaft (3) along the radial direction and the axial direction inside the housing (1); An adjustment component (6) is arranged on the housing (1) and is used to adjust the mass eccentricity of the rotary device.

2. The rotating device for wafer defect detection according to claim 1, characterized in that: The limiting component comprises: A radial limiting bearing (51), arranged inside the housing (1) and located in the circumferential direction of the rotating shaft (3), and used to prevent the rotating shaft (3) from being displaced in its radial direction; An axial limit bearing (52) is arranged inside the housing (1) and located at one end of the rotating shaft (3), and is used to prevent the rotating shaft (3) from being displaced along its axial direction.

3. The rotating device for wafer defect detection according to claim 2, characterized in that: An extension shaft (7) is provided at one end of the rotating shaft (3) connected to the driving member (4) and extending axially along the housing (1); a flange is provided on the outer periphery of the extension shaft (7); and the axial limiting bearing (52) limits the rotating shaft (3) by limiting the axial position of the flange.

4. The rotating device suitable for wafer defect detection according to claim 2, characterized in that: At least two groups of radial limit bearings (51) are provided, which are spaced apart along the axial direction of the rotating shaft (3) and sleeved on the rotating shaft (3).

5. The rotating device suitable for wafer defect detection according to claim 4, characterized in that: A sleeve (20) is arranged between two groups of radial limit bearings (51) to support two adjacent groups of radial limit bearings (51) arranged at intervals, and the sleeve (20) is in contact with the inner wall of the housing (1).

6. The rotating device suitable for wafer defect detection according to claim 2, characterized in that: An air flotation air path is provided on the housing (1), and the air flotation air path is used to supply air to the radial limit bearing (51); The air flotation air path comprises an air flotation air inlet (8) and an air flotation air hole (14); the air flotation air inlet (8) is arranged on the housing (1); the air flotation air hole (14) is arranged inside the side wall of the housing (1); and the air flotation air hole (14) is respectively connected to the air flotation air inlet (8) and the radial limit bearing (51).

7. The rotating device suitable for wafer defect detection according to claim 1, characterized in that: The housing (1) and the rotating shaft (3) are provided with a vacuum air path, and the vacuum suction cup (2) generates negative pressure through the vacuum air path; The vacuum air path comprises a connecting hole (31), a vacuum chamber (40) and a vacuum interface (9); the vacuum chamber (40) is arranged between the housing (1) and the rotating shaft (3); the connecting hole (31) is arranged in the rotating shaft (3) and is connected to the vacuum suction cup (2) at one end and to the vacuum chamber (40) at the other end; and the vacuum interface (9) is arranged through the side wall of the housing (1) and is connected to the vacuum chamber (40).

8. The rotating device for wafer defect detection according to any one of claims 1 to 7, characterized in that: Also included is a sealing member, wherein a plurality of sealing members are provided and used for sealing gaps between structures.

9. The rotating device for wafer defect detection according to any one of claims 1 to 7, characterized in that: It also includes a position sensor (30), which is located inside the housing (1) and is arranged at the bottom of the driving member (4).

10. The rotating device for wafer defect detection according to any one of claims 1 to 7, characterized in that: The outer wall of the housing (1) corresponding to the driving member (4) has a plurality of protruding structures.

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