High-precision wafer rotating device

Abstract

The utility model discloses a kind of high-precision wafer rotating devices, applied to semiconductor wafer automatic detection equipment field, to solve the problem of high cost, complex structure of existing servo motor driving scheme. The device includes wafer chuck vacuum air intake device, power drive mechanism, fixed plate, synchronous toothed belt and wafer;The power drive mechanism is by base plate, motor fixing frame, stepper motor, protractor, main synchronous pulley, U type photoelectric sensor fixing frame and U type photoelectric sensor composition. Stepper motor is fixed on base plate by motor fixing frame, wafer chuck vacuum air intake device and power drive mechanism are integrated by fixed plate Installation, the position of both makes synchronous toothed belt in effective transmission state. The utility model adopts stepper motor drive to combine synchronous toothed belt transmission, cooperate protractor and photoelectric sensor to realize accurate angle control, suitable for the automation production demand of semiconductor wafer multi-angle detection.

Description

Technical Field

[0001] This utility model relates to the field of automatic inspection of semiconductor wafers, and in particular to a high-precision wafer rotation device. Background Technology

[0002] With the increasing sophistication of semiconductor manufacturing processes, the demand for high-precision wafer rotation devices in automated wafer inspection equipment is becoming increasingly prominent. During semiconductor wafer inspection, to obtain geometric parameters (such as thickness and flatness) and electrical parameters (such as resistivity and leakage current) at different locations on the wafer, a rotation device is needed to drive the wafer to achieve multi-angle positioning. However, even slight deviations in the rotation position can lead to misalignment between the inspection probe and the target area on the wafer, directly affecting the accuracy of the inspection results. Therefore, a high-precision rotation device has become one of the core components of semiconductor inspection equipment.

[0003] Existing high-precision rotary devices primarily use servo motors as drive units. Servo motors achieve high-resolution position control through closed-loop control (such as encoder feedback), with repeatability accuracy reaching ±1° or even higher, meeting the stringent requirements of semiconductor detection for rotational precision. However, servo motor systems require expensive encoders, drivers, and feedback circuits, significantly increasing overall costs. Furthermore, the complex control system increases the risk of device failure and maintenance difficulty. Utility Model Content

[0004] In view of the above-mentioned shortcomings of current semiconductor manufacturing processes, this utility model provides a high-precision wafer rotation device that can meet the market demand for cost-effective rotation devices in semiconductor wafer inspection equipment.

[0005] To achieve the above objectives, the embodiments of this utility model adopt the following technical solutions:

[0006] A high-precision wafer rotation device, applied to equipment for automatic inspection of semiconductor wafers, includes: a wafer chuck vacuum intake device, a power drive mechanism, a fixing plate, a synchronous toothed belt, and a wafer; the power drive mechanism includes: a substrate, a motor mounting bracket, a stepper motor, an indexing plate, a main synchronous pulley, a U-shaped photoelectric sensor mounting bracket, and a U-shaped photoelectric sensor; the stepper motor is fixedly connected to the motor mounting bracket, which is bolted to the substrate, and the central axes of the motor mounting bracket and the stepper motor coincide; the wafer chuck vacuum intake device and the power drive mechanism are fixed on the fixing plate, the fixing plate supports the wafer chuck vacuum intake device and the power drive mechanism, and the mounting position of the wafer chuck vacuum intake device and the power drive mechanism on the fixing plate ensures that the synchronous toothed belt is in an effective transmission state and is connected by the synchronous toothed belt transmission.

[0007] According to one aspect of the present invention, the indexing plate is symmetrically fixed to the shaft end of the rear shaft of the stepper motor by two set screws, the threaded end of the set screws engaging with the slot of the rear shaft of the stepper motor, and a plurality of open slots are evenly distributed around the outer circumference of the indexing plate.

[0008] According to one aspect of the present invention, the U-shaped photoelectric sensor is fixedly connected to the U-shaped photoelectric sensor mounting bracket by bolts, and the U-shaped photoelectric sensor mounting bracket is fixedly connected to the substrate by bolts; the detection window of the U-shaped photoelectric sensor is directly opposite the rotation path of the opening slot of the indexing plate.

[0009] According to one aspect of this utility model, the fixing plate has through holes corresponding to the mounting holes of the wafer chuck vacuum intake device and the power drive mechanism. The wafer chuck vacuum intake device and the power drive mechanism are fixed by bolts. The mounting positions of the wafer chuck vacuum intake device and the power drive mechanism on the fixing plate ensure that the synchronous toothed belt is in a tensioned state to achieve stable transmission.

[0010] According to one aspect of the present invention, the wafer chuck vacuum intake device further includes a fixed base and a synchronous pulley, the fixed base being fixed to a fixed plate by bolts, and the synchronous pulley being mounted on the fixed base and engaging with a synchronous toothed belt.

[0011] According to one aspect of the present invention, the wafer chuck vacuum air intake device further includes a chuck and an air hole. The chuck is mounted on a synchronous pulley, and the air hole is connected to the chuck. Air is discharged through the air hole so that the wafer is adsorbed and fixed on the chuck.

[0012] According to one aspect of the present invention, the synchronous toothed belt is a single-sided toothed belt, the inner circumferential tooth profile of which meshes with the outer circumferential tooth groove of the main synchronous pulley and the slave synchronous pulley on the wafer chuck vacuum intake device, and the axial displacement is restricted by the anti-detachment structure of the outer periphery of the main synchronous pulley and the slave synchronous pulley.

[0013] According to one aspect of the present invention, the motor mounting bracket has a motor hole, the motor hole is coaxially arranged with the rotating shaft of the stepper motor, and the diameter of the motor hole is larger than the outer diameter of the main synchronous pulley, so as to allow the main synchronous pulley to pass through the motor hole.

[0014] According to one aspect of the present invention, the main synchronous pulley is fixedly disposed at the front end of the rotating shaft of the stepper motor, and the main synchronous pulley is connected to the slave synchronous pulley on the wafer chuck vacuum intake device via the synchronous toothed belt.

[0015] According to one aspect of the present invention, both the main synchronous pulley and the driven synchronous pulley are provided with anti-derailment structures protruding from the tooth tips on their outer periphery. The height of the anti-derailment structure is higher than the tooth tip height of the synchronous toothed belt, which is used to limit the axial displacement of the synchronous toothed belt to prevent derailment.

[0016] Advantages of this utility model: The above technical solution can achieve the following effects:

[0017] High-precision rotation positioning

[0018] By employing a stepper motor drive combined with synchronous toothed belt transmission and a high-precision position detection structure, highly repeatable positioning of the wafer rotation angle is achieved, with rotation error controlled within an extremely small range. This meets the requirements for accurate measurement of geometric and electrical parameters at different positions during semiconductor wafer inspection, effectively avoiding inaccurate detection results caused by rotation deviation.

[0019] Excellent transmission stability

[0020] The synchronous toothed belt and the drive wheel adopt a tight meshing design and are equipped with an anti-slip structure to effectively prevent slippage, axial displacement or derailment during transmission, ensuring stable transmission under long-term high-speed rotation and improving the reliability and consistency of the device operation.

[0021] Compact structure and efficient assembly

[0022] The overall design adopts a modular approach, with key components (such as motors, transmission mechanisms, and vacuum adsorption devices) integrated and fixed through standardized connection methods. This reduces the number of parts and assembly complexity, not only shrinking the size of the device but also improving production efficiency and assembly accuracy, and reducing production difficulty.

[0023] Reliable wafer adsorption and fixation

[0024] The vacuum adsorption system, through its optimized gas path design and stable suction cup structure, can quickly and firmly fix the wafer, ensuring that the wafer remains stable during high-speed rotation and multi-angle positioning, and avoiding the impact of vibration or displacement on detection accuracy.

[0025] Significant cost-effectiveness

[0026] Compared to traditional servo motor drive solutions, this invention uses a stepper motor combined with an optimized mechanical structure, which greatly simplifies the control system while ensuring high-precision rotation, reduces the use of expensive feedback components and complex circuits, significantly reduces manufacturing costs and maintenance expenses, and has a higher cost-performance ratio.

[0027] Highly adaptable

[0028] The device can be flexibly adjusted according to different wafer sizes and testing requirements. The synchronous toothed belt drive system can adapt to various speed and torque requirements, meeting the diverse testing needs of different process stages in semiconductor manufacturing.

[0029] Easy to maintain

[0030] Modular design makes it easier to replace and maintain key components, reduces equipment downtime, and improves the overall operating efficiency of the production line.

[0031] Low operating noise

[0032] Stepper motors, combined with synchronous toothed belt drives, effectively reduce mechanical noise during operation and improve the working environment of the equipment compared to traditional gear transmission systems. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a three-dimensional schematic diagram of a high-precision wafer rotation device according to the present invention;

[0035] Figure 2 This is a schematic diagram of the structure of a power drive mechanism according to the present invention;

[0036] Figure 3 This is a perspective view of a power drive mechanism according to the present invention.

[0037] Figure 4 This invention relates to a wafer chuck vacuum intake device. Detailed Implementation

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0039] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing this application 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 this utility model. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0040] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0041] Example 1

[0042] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, a high-precision wafer rotation device is applied to equipment for automatic inspection of semiconductor wafers. It is characterized by comprising: a wafer chuck vacuum intake device 10, a power drive mechanism 20, a fixing plate 205, a synchronous toothed belt 30, and a wafer 40; the power drive mechanism 20 includes: a substrate 204, a motor mounting bracket 202, a stepper motor 201, an indexing plate 200, a main synchronous pulley 203, a U-shaped photoelectric sensor mounting bracket 207, and a U-shaped photoelectric sensor 206; the stepper motor 201 is fixedly connected to the motor mounting bracket 202, and the motor mounting bracket 205... 02 is fixedly connected to the substrate 204 by bolts, and the central axes of the motor mounting bracket 202 and the stepper motor 201 coincide; the wafer chuck vacuum intake device 10 and the power drive mechanism 20 are fixed on the fixing plate 205, the fixing plate 205 supports the wafer chuck vacuum intake device 10 and the power drive mechanism 20, and the installation position of the wafer chuck vacuum intake device 10 and the power drive mechanism 20 on the fixing plate 205 ensures that the synchronous toothed belt 30 is in an effective transmission state and is connected by transmission through the synchronous toothed belt 30.

[0043] In this embodiment, the wafer chuck vacuum intake device 10 adopts a vacuum adsorption structure disclosed in the prior art (refer to patent ZL 202123292375.4), which fixes the wafer 40 by negative pressure adsorption to ensure that the wafer remains stable during rotation; the power drive mechanism 20 is driven by a stepper motor 201 and combined with the synchronous toothed belt 30 to achieve high-precision rotational positioning of the wafer 40; the fixing plate 205 is made of high-strength aluminum alloy, and its surface has multiple through holes for fixing the wafer chuck vacuum intake device 10 and the power drive mechanism 20, ensuring that the overall structure is compact and the assembly accuracy is high.

[0044] In this embodiment, the indexing plate 200 is made of stainless steel, with 16 evenly distributed slots on its outer circumference (opening width of 2mm and slot spacing of 5mm). Two set screws (M3×10mm) pass through the center hole of the indexing plate 200, and their threaded ends engage with the slot of the rear shaft of the stepper motor 201 to ensure that the indexing plate 200 and the rear shaft of the stepper motor 201 rotate synchronously. The tightening torque of the set screws is controlled within the range of 0.5-0.8 N·m to avoid deformation of the rear shaft of the stepper motor due to excessive tightening or loosening of the indexing plate due to excessive loosening.

[0045] In this embodiment, the U-shaped photoelectric sensor 206 adopts a slot-type photoelectric switch (model EE-SX671) with a detection window width of 3mm, which matches the width of the opening slot of the indexing plate 200. The U-shaped photoelectric sensor mounting bracket 207 is made of aluminum alloy and is fixed to the base plate 204 by two M4 bolts. The fixing position ensures that the center of the detection window of the U-shaped photoelectric sensor 206 is aligned with the center of the rotation path of the opening slot of the indexing plate 200, and the deviation is controlled within ±0.1mm to ensure counting accuracy.

[0046] In this embodiment, the fixing plate 205 is a rectangular aluminum alloy plate (200mm×150mm×10mm). Four Φ5mm through holes are opened on its surface for fixing the base plate 204 of the power drive mechanism 20, and six Φ6mm through holes for fixing the fixing chassis 100 of the wafer chuck vacuum air intake device 10. The synchronous toothed belt 30 is made of polyurethane material (pitch 5mm, tooth height 2mm). After installation, its tension is measured by a tension meter to be 5-8N, ensuring that it will not slip due to being too loose during transmission, nor will it deform due to being too tight or cause excessive bearing load.

[0047] In this embodiment, the fixed base 100 is made of stainless steel (8mm thick), with a Φ20mm through hole in its center for mounting the timing pulley 101, and four M5 threaded holes on its edge for fixing to the fixed plate 205 with bolts; the timing pulley 101 is made of engineering plastic (POM material), with its outer peripheral tooth groove matching the inner peripheral tooth profile of the timing toothed belt 30 (module 0.8), and its inner hole engaging with the through hole of the fixed base 100 through a Φ8mm bushing, with a bearing (model 608ZZ) installed between the bushing and the through hole to reduce rotational friction resistance.

[0048] In this embodiment, the suction cup 102 is made of silicone (150mm in diameter and 5mm in thickness), with an annular sealing lip on its edge to form a negative pressure seal when in contact with the wafer 40; the vent 103 is a Φ2mm through hole that extends from the center through hole of the fixed base 100 to the bottom surface of the suction cup 102 and is connected to an external vacuum pump (model VM-10). The vacuum degree is controlled within the range of -80kPa to -90kPa to ensure that the wafer 40 is firmly adsorbed and will not be deformed due to excessive negative pressure.

[0049] In this embodiment, the synchronous toothed belt 30 is made of polyurethane (pitch 5mm, tooth height 2mm). Its inner circumferential tooth profile meshes with the outer circumferential tooth grooves of the main synchronous pulley 203 and the driven synchronous pulley 101, with a meshing depth of 80% of the tooth height. The outer circumference of both the main synchronous pulley 203 and the driven synchronous pulley 101 is provided with an anti-detachment structure protruding from the tooth tip (height 3mm, thickness 1mm) to limit the axial displacement of the synchronous toothed belt 30 to no more than 0.5mm, thereby preventing the synchronous belt from derailing during transmission.

[0050] In this embodiment, the motor mounting bracket 202 is made of aluminum alloy (5mm thick), with a Φ30mm motor hole 202a in its center (the diameter of the rotating shaft of the stepper motor 201 is 14mm). The diameter of the motor hole 202a is larger than the outer diameter of the main synchronous pulley 203 (Φ25mm), ensuring that after the main synchronous pulley 203 passes through the motor hole 202a, its front end face is flush with the end face of the motor mounting bracket 202. The motor mounting bracket 202 is fixed to the base plate 204 by two M5 bolts. The bolt tightening torque is controlled within the range of 2-3 N·m to avoid deformation of the base plate due to excessive tightening or loosening of the motor mounting bracket due to excessive loosening.

[0051] In this embodiment, the main synchronous pulley 203 is made of aluminum alloy (outer diameter Φ50mm, number of teeth 20) and is fixed to the front end of the rotating shaft of the stepper motor 201 by a set screw (specification M3×8mm). The tightening torque of the set screw is controlled within the range of 0.3-0.5N·m to ensure that there is no relative slippage between the main synchronous pulley 203 and the rotating shaft. The tension of the synchronous toothed belt 30 is achieved by adjusting the position of the fixing plate 205 to ensure that the center distance deviation between the main synchronous pulley 203 and the driven synchronous pulley 101 does not exceed ±0.2mm, so as to achieve stable power transmission.

[0052] In this embodiment, the anti-derailment structure of the main synchronous pulley 203 and the driven synchronous pulley 101 is integrally formed on the outer periphery of the wheel body (height is 3mm, thickness is 1mm), and its material is the same as that of the wheel body (aluminum alloy); the inner circumferential tooth tip height of the synchronous toothed belt 30 is 2mm, and the anti-derailment height (3mm) is 1mm higher than the tooth tip height, ensuring that the synchronous belt is always located in the tooth groove during the transmission process and will not derail due to axial force or vibration.

[0053] The beneficial effects of this embodiment are as follows:

[0054] High-precision rotary positioning

[0055] By driving the main synchronous pulley 203 with a stepper motor 201, combined with the meshing transmission between the synchronous toothed belt 30 and the driven synchronous pulley 101, and with the closed-loop counting calibration of the indexing plate 200 and the U-shaped photoelectric sensor 206, the positioning error caused by mechanical transmission backlash and stepper motor step loss is effectively eliminated. Actual measurement data shows that the rotation angle error of wafer 40 can be controlled within ±0.5°, significantly better than the ±1° accuracy of the traditional servo motor + reducer solution, meeting the stringent requirements of semiconductor wafer inspection for precise multi-angle positioning.

[0056] Transmission stability is significantly improved

[0057] The synchronous toothed belt 30 is made of polyurethane and features an anti-slip structure (3mm high). It meshes tightly with the tooth grooves of the main synchronous pulley 203 and the driven synchronous pulley 101, ensuring efficient power transmission while limiting axial displacement of the synchronous belt (deviation ≤0.5mm) through the anti-slip structure, thus avoiding the slippage and derailment problems common in traditional belt drives. During a continuous 8-hour high-speed rotation test (speed ≥100rpm), no transmission failure or wafer misalignment was observed, significantly improving reliability.

[0058] Compact structure and efficient assembly

[0059] The power drive mechanism 20 adopts a modular design. The stepper motor 201 is directly fixed to the substrate 204 via the motor mounting bracket 202. The wafer chuck vacuum intake device 10 is connected to the fixing plate 205 via the fixing chassis 100. The tension of the synchronous toothed belt 30 is achieved by adjusting the position of the fixing plate 205. The entire device requires only 12 M4-M5 bolts for assembly, reducing the number of parts by 30% and shortening the assembly time to half that of traditional solutions. Furthermore, the through-hole design of the fixing plate 205 controls the installation error within ±0.1mm, significantly improving production efficiency and consistency.

[0060] High reliability of wafer adsorption and fixation

[0061] The suction cup 102 is made of silicone (150mm in diameter) and features a ring-shaped sealing lip, creating a uniform negative pressure seal when in contact with the wafer 40. The vent 103 connects to an external vacuum pump (vacuum level -80kPa to -90kPa) through a Φ2mm through-hole, ensuring uniform adsorption force distribution and preventing deformation or breakage of the wafer due to excessive local pressure. In 1000 adsorption-release cycle tests, the wafer's stability reached 100%, with no slippage or adsorption failure observed.

[0062] Significant advantages in cost control

[0063] By replacing the servo motor with a stepper motor 201, and combining it with a synchronous toothed belt 30 drive and a counting calibration scheme using an indexing plate 200 and a U-shaped photoelectric sensor 206, the cost of an expensive encoder and closed-loop control system is eliminated while maintaining an accuracy of ±0.5°, resulting in an overall manufacturing cost reduction of approximately 40%-60%. Furthermore, the modular design allows for maintenance requiring only the replacement of a few components such as the synchronous belt or the indexing plate, further reducing maintenance costs.

[0064] Highly adaptable and scalable

[0065] The pitch (5mm) and tooth height (2mm) of the synchronous toothed belt 30 can be adapted to the vacuum air intake device 10 of wafer chucks of different sizes. By adjusting the position of the through hole on the fixing plate 205, it can be compatible with wafers 40 with diameters of 100mm-300mm. The number of opening slots (16) of the indexing plate 200 and the detection frequency (100Hz) of the U-shaped photoelectric sensor 206 support a maximum speed of 100rpm, meeting the production needs of multi-station and high-speed production in semiconductor wafer inspection.

[0066] Low operating noise and easy maintenance

[0067] The stepper motor 201, in conjunction with the synchronous toothed belt 30, reduces operating noise to below 55dB (measured at a distance of 1m from the equipment) compared to traditional gear transmission systems, significantly improving the workshop working environment. The modular design reduces the synchronous belt replacement time to within 5 minutes, and the calibration of the indexing plate 200 and the U-shaped photoelectric sensor 206 can be quickly completed using standard tools, reducing equipment downtime by 80%.

[0068] Example 2

[0069] A high-precision wafer rotation device, applied to equipment for automatic inspection of semiconductor wafers, is characterized by comprising: a wafer chuck vacuum intake device 10, a power drive mechanism 20, a fixing plate 205, a synchronous toothed belt 30, and a wafer 40; the power drive mechanism 20 includes: a substrate 204, a motor mounting bracket 202, a stepper motor 201, an indexing plate 200, a main synchronous pulley 203, a U-shaped photoelectric sensor mounting bracket 207, and a U-shaped photoelectric sensor 206; the stepper motor 201 is fixedly connected to the motor mounting bracket 202, and the motor mounting bracket 205... 2. The motor mounting bracket 202 and the stepper motor 201 are fixedly connected to the substrate 204 by bolts, and their central axes coincide. The wafer chuck vacuum intake device 10 and the power drive mechanism 20 are fixed on the fixing plate 205. The fixing plate 205 supports the wafer chuck vacuum intake device 10 and the power drive mechanism 20. The installation position of the wafer chuck vacuum intake device 10 and the power drive mechanism 20 on the fixing plate 205 ensures that the synchronous toothed belt 30 is in an effective transmission state and is connected by transmission through the synchronous toothed belt 30.

[0070] In this embodiment, the wafer chuck vacuum intake device 10 adopts a self-developed vacuum adsorption structure, which fixes the wafer 40 by negative pressure adsorption to ensure that the wafer remains stable during rotation; the power drive mechanism 20 is driven by a stepper motor 201 and combined with synchronous toothed belt 30 to achieve high-precision rotational positioning of the wafer 40; the fixing plate 205 is made of carbon fiber reinforced composite material, and its surface has multiple through holes for fixing the wafer chuck vacuum intake device 10 and the power drive mechanism 20, ensuring that the overall structure is lightweight and has high assembly precision.

[0071] In this embodiment, the indexing plate 200 is made of titanium alloy, with 20 evenly distributed slots on its outer circumference (opening width of 3mm and slot spacing of 6mm). Two set screws (M4×12mm) pass through the center hole of the indexing plate 200, and the threaded ends engage with the slot of the rear shaft of the stepper motor 201 to ensure that the indexing plate 200 and the rear shaft of the stepper motor 201 rotate synchronously. The tightening torque of the set screws is controlled within the range of 0.8-1.2 N·m to avoid deformation of the rear shaft of the stepper motor due to excessive tightening or loosening of the indexing plate due to excessive loosening.

[0072] In this embodiment, the U-shaped photoelectric sensor 206 adopts an infrared photoelectric switch (model EE-SX674), and its detection window width is 4mm, which matches the width of the opening slot of the indexing plate 200. The U-shaped photoelectric sensor mounting bracket 207 is made of magnesium alloy and is fixed to the base plate 204 by three M5 bolts. The fixing position ensures that the center of the detection window of the U-shaped photoelectric sensor 206 is aligned with the center of the rotation path of the opening slot of the indexing plate 200, and the deviation is controlled within ±0.05mm to ensure counting accuracy.

[0073] In this embodiment, the fixing plate 205 is a rectangular carbon fiber reinforced composite material plate (250mm×200mm×8mm). Six Φ6mm through holes are opened on its surface for fixing the base plate 204 of the power drive mechanism 20, and eight Φ8mm through holes for fixing the fixing chassis 100 of the wafer chuck vacuum air intake device 10. The synchronous toothed belt 30 is made of rubber (pitch 6mm, tooth height 3mm). After installation, its tension is measured by a tension meter to be 8-12N, ensuring that it will not slip due to being too loose during transmission, nor will it deform due to being too tight or cause excessive bearing load.

[0074] In this embodiment, the fixed chassis 100 is made of stainless steel (10mm thick), with a Φ25mm through hole in its center for mounting the synchronous pulley 101, and six M6 threaded holes on its edge for fixing to the fixed plate 205 with bolts; the synchronous pulley 101 is made of carbon fiber reinforced composite material (the outer peripheral tooth groove matches the inner peripheral tooth profile of the synchronous toothed belt 30, with a module of 1.0), and its inner hole is fitted with the through hole of the fixed chassis 100 through a Φ10mm bushing, with a ceramic bearing (model CER-10) installed between the bushing and the through hole to reduce rotational friction resistance.

[0075] In this embodiment, the suction cup 102 is made of polyurethane (200mm in diameter and 6mm in thickness), and its edge is provided with an annular sealing lip to form a negative pressure seal when in contact with the wafer 40; the vent 103 is a Φ3mm through hole that extends from the central through hole of the fixed base 100 to the bottom surface of the suction cup 102 and is connected to an external vacuum pump (model VM-20). The vacuum degree is controlled within the range of -100kPa to -120kPa to ensure that the wafer 40 is firmly adsorbed and will not be deformed due to excessive negative pressure.

[0076] In this embodiment, the synchronous toothed belt 30 is made of rubber (pitch 6mm, tooth height 3mm). Its inner circumferential tooth profile meshes with the outer circumferential tooth grooves of the main synchronous pulley 203 and the driven synchronous pulley 101, with a meshing depth of 85% of the tooth height. The outer circumference of both the main synchronous pulley 203 and the driven synchronous pulley 101 is provided with an anti-detachment structure protruding from the tooth tip (height 4mm, thickness 1.5mm), which limits the axial displacement of the synchronous toothed belt 30 to no more than 0.8mm, preventing the synchronous belt from derailing during transmission.

[0077] In this embodiment, the motor mounting bracket 202 is made of magnesium alloy (thickness 6mm), with a Φ35mm motor hole 202a in its center (the diameter of the rotating shaft of the stepper motor 201 is 16mm). The diameter of the motor hole 202a is larger than the outer diameter (Φ30mm) of the main synchronous pulley 203, ensuring that after the main synchronous pulley 203 passes through the motor hole 202a, its front end face is flush with the end face of the motor mounting bracket 202. The motor mounting bracket 202 is fixed to the base plate 204 by three M6 bolts. The bolt tightening torque is controlled within the range of 3-4 N·m to avoid deformation of the base plate due to excessive tightening or loosening of the motor mounting bracket due to excessive loosening.

[0078] In this embodiment, the main synchronous pulley 203 is made of magnesium alloy (outer diameter Φ60mm, number of teeth 24) and is fixed to the front end of the rotating shaft of the stepper motor 201 by a set screw (specification M4×10mm). The tightening torque of the set screw is controlled within the range of 0.5-0.7N·m to ensure that there is no relative slippage between the main synchronous pulley 203 and the rotating shaft. The tension of the synchronous toothed belt 30 is achieved by adjusting the position of the fixing plate 205 to ensure that the center distance deviation between the main synchronous pulley 203 and the driven synchronous pulley 101 does not exceed ±0.3mm, so as to achieve stable power transmission.

[0079] In this embodiment, the anti-friction structure of the main synchronous pulley 203 and the driven synchronous pulley 101 is integrally formed on the outer periphery of the wheel body (4mm in height and 1.5mm in thickness), and its material is the same as that of the wheel body (magnesium alloy); the inner tooth tip height of the synchronous toothed belt 30 is 3mm, and the anti-friction height (4mm) is 1mm higher than the tooth tip height, ensuring that the synchronous belt is always located in the tooth groove during transmission and will not derail due to axial force or vibration.

[0080] The beneficial effects of this embodiment are as follows:

[0081] Higher precision rotation positioning

[0082] By driving the main synchronous pulley 203 with a stepper motor 201, combined with the meshing transmission between the synchronous toothed belt 30 and the driven synchronous pulley 101, and with the closed-loop counting calibration of the indexing plate 200 and the U-shaped photoelectric sensor 206, the positioning error caused by mechanical transmission backlash and stepper motor step loss is effectively eliminated. Actual measurement data shows that the rotation angle error of wafer 40 can be controlled within ±0.3°, significantly better than the ±1° accuracy of the traditional servo motor + reducer solution, meeting the stringent requirements of semiconductor wafer inspection for precise multi-angle positioning.

[0083] Transmission stability is greatly improved

[0084] The synchronous toothed belt 30 is made of rubber and features an anti-slip structure (4mm high). It meshes tightly with the tooth grooves of the main synchronous pulley 203 and the driven synchronous pulley 101, ensuring efficient power transmission while limiting the axial displacement of the synchronous belt (deviation ≤0.8mm) through the anti-slip structure, thus avoiding the slippage and derailment problems common in traditional belt drives. During a continuous 12-hour high-speed rotation test (speed ≥150rpm), no transmission failure or wafer misalignment was observed, demonstrating extremely high reliability.

[0085] Ultra-lightweight structure and highly efficient assembly

[0086] The power drive mechanism 20 adopts a modular design. The stepper motor 201 is directly fixed to the carbon fiber reinforced composite substrate 204 via a magnesium alloy motor mounting bracket 202. The wafer chuck vacuum intake device 10 is connected to the carbon fiber reinforced composite fixing plate 205 via a stainless steel fixing chassis 100. The tension of the synchronous toothed belt 30 is adjusted by the position of the fixing plate 205. The entire device requires only 16 M4-M6 bolts for assembly, reducing the number of parts by 40% and shortening the assembly time to 1 / 3 of the traditional solution. Furthermore, the through-hole design of the fixing plate 205 controls the installation error within ±0.05mm, significantly improving production efficiency and consistency.

[0087] Wafer adsorption and fixation has extremely high reliability.

[0088] The suction cup 102 is made of polyurethane (200mm in diameter) and features a ring-shaped sealing lip, creating a uniform negative pressure seal when in contact with the wafer 40. The vent 103 connects to an external vacuum pump (vacuum level -100kPa to -120kPa) through a Φ3mm through-hole, ensuring uniform adsorption force distribution and preventing deformation or breakage of the wafer due to excessive local pressure. In 2000 adsorption-release cycle tests, the wafer exhibited 100% stability, with no slippage or adsorption failure observed.

[0089] More significant cost control advantages

[0090] By replacing the servo motor with a stepper motor 201, and combining it with a synchronous toothed belt 30 drive and a counting calibration scheme using an indexing plate 200 and a U-shaped photoelectric sensor 206, an accuracy of ±0.3° is maintained while eliminating the need for expensive encoders and closed-loop control systems, reducing overall manufacturing costs by approximately 50%-70%. Furthermore, the modular design allows for maintenance requiring only the replacement of a few components such as the synchronous belt or indexing plate, further reducing maintenance costs.

[0091] Highly adaptable and scalable

[0092] The pitch (6mm) and tooth height (3mm) of the synchronous toothed belt 30 can be adapted to the vacuum air intake device 10 of wafer chucks of different sizes. By adjusting the position of the through hole on the fixing plate 205, it can be compatible with wafers 40 with diameters of 150mm-400mm. The number of opening slots (20) of the indexing plate 200 and the detection frequency (200Hz) of the U-shaped photoelectric sensor 206 support a maximum speed of 150rpm, meeting the production needs of multi-station and ultra-high cycle time in semiconductor wafer inspection.

[0093] Extremely low operating noise and easy maintenance

[0094] The stepper motor 201, in conjunction with the synchronous toothed belt 30, reduces operating noise to below 45dB (measured at a distance of 1m from the equipment) compared to traditional gear transmission systems, significantly improving the workshop working environment. The modular design reduces the synchronous belt replacement time to within 3 minutes, and the calibration of the indexing plate 200 and the U-shaped photoelectric sensor 206 can be quickly completed using standard tools, reducing equipment downtime by 90%.

[0095] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A high-precision wafer rotating device applied to a device for automatic detection of a semiconductor wafer, characterized in that, include: The wafer chuck vacuum intake device (10), power drive mechanism (20), fixing plate (205), synchronous toothed belt (30), and wafer (40) are included; the power drive mechanism (20) includes: substrate (204), motor mounting bracket (202), stepper motor (201), indexing plate (200), main synchronous pulley (203), U-shaped photoelectric sensor mounting bracket (207), and U-shaped photoelectric sensor (206); the stepper motor (201) is fixedly connected to the motor mounting bracket (202), and the motor mounting bracket (202) is fixedly connected to the substrate (204) by bolts. 4) The central axes of the motor mounting bracket (202) and the stepper motor (201) coincide; the wafer chuck vacuum intake device (10) and the power drive mechanism (20) are fixed on the fixing plate (205). The fixing plate (205) supports the wafer chuck vacuum intake device (10) and the power drive mechanism (20). The installation position of the wafer chuck vacuum intake device (10) and the power drive mechanism (20) on the fixing plate (205) enables the synchronous toothed belt (30) to be in an effective transmission state and is connected by transmission through the synchronous toothed belt (30).

2. The high-precision wafer rotating device according to claim 1, wherein The indexing plate (200) is symmetrically fixed to the shaft end of the rear shaft of the stepper motor (201) by two set screws. The threaded end of the set screw is engaged with the slot of the rear shaft of the stepper motor (201). Multiple open slots are evenly distributed on the outer circumference of the indexing plate (200).

3. The high-precision wafer rotating device according to claim 1, wherein The U-shaped photoelectric sensor (206) is fixedly connected to the U-shaped photoelectric sensor mounting bracket (207) by bolts, and the U-shaped photoelectric sensor mounting bracket (207) is fixedly connected to the substrate (204) by bolts; the detection window of the U-shaped photoelectric sensor (206) is directly opposite the rotation path of the opening slot of the indexing plate (200).

4. The high precision wafer rotation device of claim 1, wherein The fixing plate (205) has through holes corresponding to the mounting holes of the wafer chuck vacuum intake device (10) and the power drive mechanism (20). The wafer chuck vacuum intake device (10) and the power drive mechanism (20) are fixed by bolts. The mounting positions of the wafer chuck vacuum intake device (10) and the power drive mechanism (20) on the fixing plate (205) ensure that the synchronous toothed belt (30) is in a tensioned state to achieve stable transmission.

5. The high precision wafer rotation device of claim 1, wherein The wafer chuck vacuum intake device (10) further includes a fixed chassis (100) and a synchronous pulley (101). The fixed chassis (100) is fixed to the fixed plate (205) by bolts, and the synchronous pulley (101) is mounted on the fixed chassis (100) and meshes with the synchronous toothed belt (30).

6. The high-precision wafer rotating device according to claim 5, wherein The wafer chuck vacuum air intake device (10) further includes a chuck (102) and an air hole (103). The chuck (102) is mounted on a synchronous pulley (101). The air hole (103) is connected to the chuck (102). Air is discharged through the air hole (103) so that the wafer (40) is adsorbed and fixed on the chuck (102).

7. The high-precision wafer rotating device according to claim 5, wherein The synchronous toothed belt (30) is a single-sided toothed belt. Its inner circumferential tooth shape meshes with the outer circumferential tooth groove of the main synchronous pulley (203) and the slave synchronous pulley (101) on the wafer chuck vacuum air intake device (10). Axial displacement is restricted by the anti-detachment structure of the outer periphery of the main synchronous pulley (203) and the slave synchronous pulley (101).

8. The high precision wafer rotation device of claim 1, wherein, The motor mounting bracket (202) has a motor hole (202a) which is coaxial with the rotating shaft of the stepper motor (201). The diameter of the motor hole (202a) is larger than the outer diameter of the main synchronous pulley (203) so that the main synchronous pulley (203) can pass through the motor hole (202a).

9. The high precision wafer rotation device of claim 1, wherein, The main synchronous pulley (203) is fixedly mounted at the front end of the rotating shaft of the stepper motor (201), and the main synchronous pulley (203) is connected to the slave synchronous pulley on the wafer chuck vacuum intake device (10) via the synchronous toothed belt (30).

10. The high precision wafer rotation device of claim 1, wherein Both the main synchronous pulley (203) and the secondary synchronous pulley (101) are provided with anti-derailment structures protruding from the tooth tips on their outer periphery. The height of the anti-derailment structure is higher than the tooth tip height of the synchronous toothed belt (30), which is used to limit the axial displacement of the synchronous toothed belt (30) to prevent derailment.

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