Wafer edge polishing device and system and tension detection and control method

Abstract

The invention relates to a wafer edge polishing device and system and a tension detection and control method.The wafer edge polishing device comprises a polishing module and a polishing belt, and the polishing module comprises a belt supplying mechanism, a belt supplying guide wheel assembly, a pressure feeding assembly, a belt collecting guide wheel assembly and a belt collecting mechanism; the wafer edge polishing device further comprises a detection mechanism arranged on at least one side of the pressure feeding assembly. The detection mechanism comprises a force measuring sensor and a force conduction piece arranged on the force measuring sensor, the force measuring sensor is used for detecting the acting force borne by the force conduction piece, and the polishing belt is further wound around the force conduction piece and can generate the acting force on the force conduction piece. According to the wafer edge polishing device, direct online detection of the tension of the polishing belt is carried out through the acting force generated by the polishing belt on the force conduction piece and further through the difference of the acting force generated by the force conduction piece on the force measurement sensor by the force measurement sensor, accurate control over the tension of the polishing belt is facilitated, and the process control difficulty of edge polishing is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the field of wafer edge polishing technology, and in particular to a wafer edge polishing device, system, tension detection and control method. Background Art

[0002] Chemical Mechanical Planarization (CMP) is a global surface planarization technology used to reduce the impact of wafer thickness variation and surface morphology during semiconductor manufacturing, and CMP has become the most widely used surface planarization technology in semiconductor manufacturing.

[0003] Wafer edge polishing is the process of polishing and grinding the side edges of the wafer using a wafer edge polishing device to remove defects such as particles, fragments, scratches, etc. on the side of the wafer, and to form a specific wafer edge profile, making the silicon wafer surface have higher strength.

[0004] Figure 1 It is a structural schematic diagram of a wafer edge polishing device in the prior art, which mainly includes a polishing belt and a polishing module. The polishing module includes a tape supply mechanism, multiple tape supply guide wheels, a pressure feeding assembly, multiple tape take-up guide wheels and a tape take-up mechanism which are arranged in sequence. The tape supply mechanism includes a tape supply winding wheel and a tape supply motor for driving the tape supply winding wheel to rotate. The tape take-up mechanism includes a tape take-up winding wheel and a tape take-up motor for driving the tape take-up winding wheel to rotate. Multiple tape supply guide wheels are arranged in sequence, and multiple tape take-up guide wheels are arranged in sequence. Two ends of the polishing belt are respectively connected to the tape supply winding wheel and the tape take-up winding wheel, and the polishing belt is wound around multiple tape supply guide wheels, the pressure feeding assembly and multiple tape take-up guide wheels in sequence. The wafer is arranged correspondingly to the pressure feeding assembly, and the wafer and the pressure feeding assembly are respectively located on both sides of the polishing belt. During edge polishing, the polishing belt runs toward the tape take-up side, and the pressure feeding assembly is pushed out by the cylinder to contact the edge of the wafer. The polishing belt runs continuously to polish the edge of the wafer.

[0005] In actual working conditions, when wafers are polished, it is necessary to regulate the wafer polishing device, especially the tension of the polishing belt, mainly to detect and control the tension of the polishing belt to reduce the loss of the wafer and improve the polishing effect of wafer polishing. Existing wafer polishing devices usually use motors (force control mode) to detect and control the tension on the polishing belt, and adjust the speed of the supply motor and the take-up motor according to the change of the actual torque of each motor. The retraction and release amount of the polishing belt on both sides of the supply side and the take-up side are adjusted by the speed change, thereby realizing the tension adjustment in the polishing belt, and the tension control of the polishing belt is realized by the torque self-adjustment of the motors on each side.

[0006] However, both the supply motor and the take-up motor are far away from the wafer polishing position, and the force output by the supply motor / take-up motor is used to replace the tension of the polishing belt. However, the force output by the supply motor / take-up motor is not the direct tension on the polishing belt, and is fundamentally different from the direct tension on the polishing belt, and cannot accurately reflect the real tension of the polishing belt. Therefore, the current method of detecting and controlling the tension of the polishing belt through the torque of the motor cannot achieve accurate control of the tension of the polishing belt, increasing the difficulty of controlling the wafer edge polishing process, the control of the polishing belt tension is inaccurate, the delay is high, and the tension is difficult to stabilize after repeated changes, which is easy to produce unfavorable stripe patterns on the edge of the wafer. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a wafer edge polishing device capable of more accurately detecting and controlling the tension of the polishing belt in view of one or more deficiencies in the prior art.

[0008] The second object of the present invention is to provide a wafer edge polishing system, in which the tension detection and control of the polishing belt are more accurate, and the control difficulty of the wafer edge polishing process is greatly reduced.

[0009] A third object of the present invention is to provide a method for detecting tension of a polishing belt.

[0010] The fourth object of the present invention is to provide a method for controlling the tension of a polishing belt, by which the tension of the polishing belt can be controlled more accurately, thereby reducing the control difficulty of the wafer edge polishing process.

[0011] In order to solve one or more of the above technical problems, the present invention adopts the following technical solutions:

[0012] A wafer edge polishing device comprises a polishing module and a polishing belt, wherein the polishing module comprises a belt supply mechanism, a belt supply guide wheel assembly, a pressure feed assembly, a belt take-up guide wheel assembly and a belt take-up mechanism;

[0013] The tape supply mechanism, tape supply guide wheel assembly, pressure feed assembly, tape take-up guide wheel assembly and tape take-up mechanism are arranged in sequence, the two ends of the polishing tape are respectively connected to the tape supply mechanism and the tape take-up mechanism, and the polishing tape is wound around the tape supply guide wheel assembly, the pressure feed assembly and the tape take-up guide wheel assembly in sequence, and the wafer edge polishing device also includes a detection mechanism arranged on at least one side of the pressure feed assembly;

[0014] The detection mechanism includes a force sensor and a force transmission component arranged on the force sensor, the force sensor is used to detect the force applied to the force transmission component, the polishing belt is also wound around the force transmission component, and the tension of the polishing belt can change the force.

[0015] Since the tension of the polishing belt is generated by deformation and the polishing belt cannot be cut off for measurement, there is no good solution in the prior art for online detection of the tension of the polishing belt. The present application adopts the above-mentioned solution, which can convert the tension in the polishing belt into a force acting on the force transmission component, and then detect the pressure of the force transmission component on the force sensor through the force sensor, thereby detecting the tension in the polishing belt, thereby realizing online detection of the tension of the polishing belt, and the detection and control of the tension of the polishing belt are more accurate, which is convenient for accurate control of the wafer edge polishing process, and helps to maintain a basically constant tension of the polishing belt during edge polishing to ensure the uniformity of edge polishing, and is not easy to produce adverse stripe patterns at the edge of the wafer, thereby ensuring the edge polishing effect.

[0016] Optionally, in the wafer edge polishing device as described above, the detection mechanism also includes a first guide wheel and a second guide wheel arranged on both sides of the force transmission member, and the polishing belt is arranged to pass around the first guide wheel, the force transmission member and the second guide wheel in sequence.

[0017] Optionally, the first guide wheel and / or the second guide wheel are arranged in a position-adjustable manner, so that the angle between the part of the polishing belt between the first guide wheel and the force transmission member and the part of the polishing belt between the second guide wheel and the force transmission member can be adjusted through different installation positions of the first guide wheel and the second guide wheel, and the distance between the first guide wheel and the force transmission member can also be adjusted through different installation positions of the first guide wheel and / or the second guide wheel, so as to change the tension of the polishing belt and achieve the effect of adjusting the tension of the polishing belt.

[0018] Optionally, the rotating shafts of the first guide wheel and the second guide wheel are connected to a position adjustment device, and the position adjustment device is used to make the rotating shafts of the first guide wheel and the second guide wheel move upward and downward synchronously, and / or change positions synchronously towards and in opposite directions.

[0019] Optionally, the synchronously changing positions in opposite directions makes the angle between the partial polishing belt between the first guide wheel and the force transmission member and the partial polishing belt between the second guide wheel and the force transmission member change in the range of -5 to 5°.

[0020] Furthermore, the angle is -2 to 2°, and is actually as close to 0° as possible, so that the portion of the polishing belt between the first guide wheel and the force transmission component and the portion of the polishing belt between the second guide wheel and the force transmission component are parallel to each other, preventing the two portions of the polishing belt from having an angle that affects the measurement result of the tension of the polishing belt.

[0021] Optionally, in the wafer edge polishing device as described above, part of the polishing belt between the first guide wheel and the force transmission member and part of the polishing belt between the second guide wheel and the force transmission member are arranged parallel to each other to ensure the measurement accuracy of the tension of the polishing belt.

[0022] Optionally, the force sensor is fixedly arranged, and the force transmission component is a fixed pulley arranged on the force sensor.

[0023] In the prior art, the tension detection method of the polishing belt (reading the tension through a force-controlled motor) is such that the torque output by the motor is greatly affected by external factors, among which the mass of the polishing belt winding wheel (including the polishing belt), the remaining polishing belt thickness on the winding wheel (rotation radius), the acceleration of the winding wheel, the friction between the guide wheel and the polishing belt, and other factors can all affect the torque of the motor; therefore, the torque collected by the motor fluctuates relatively greatly, and it is impossible to accurately detect and control the tension of the polishing belt, which increases the difficulty of controlling the wafer edge polishing process. The tension of the polishing belt is difficult to stabilize during repeated changes, and it is difficult to ensure a constant tension of the polishing belt during the edge polishing process.

[0024] In the present invention, the fixed pulley principle is used to convert the tension in the polishing belt into the external force of the fixed pulley, and the force acting on the fixed pulley on the force sensor is detected by the force sensor, thereby detecting the tension of the polishing belt, and realizing online detection of the tension of the polishing belt. In addition, the above technical solution of the present application also eliminates a large number of influencing factors in the existing tension detection method (reading the tension through a force control motor). Basically, except for the friction of the guide wheel and the error of the force sensor, the measured value is almost completely close to the true value.

[0025] Optionally, in the wafer edge polishing device as described above, the detection mechanism also includes a fixed mounting plate, the force sensor is fixedly arranged on the mounting plate, the fixed pulley includes a fixed pulley bracket arranged on the force sensor and a fixed pulley guide wheel arranged on the fixed pulley bracket and rotating around its own axis, and the polishing belt is wound around the fixed pulley guide wheel.

[0026] Optionally, the force sensor is a tension sensor, a pressure sensor or a tension-pressure sensor.

[0027] Optionally, in the wafer edge polishing device as described above, the detection mechanism is respectively provided on both sides of the pressure feed assembly.

[0028] Optionally, the detection mechanisms on both sides are recorded as a supply side detection mechanism and a take-up side detection mechanism, and the supply side detection mechanism is arranged between the supply guide wheel assembly and the pressure feeding assembly; the take-up side detection mechanism is arranged between the pressure feeding assembly and the take-up guide wheel assembly. Both the supply side detection mechanism and the take-up side detection mechanism are arranged close to the wafer position to detect the tension of the polishing belt closest to the wafer position. The detected tension is the actual tension of the polishing belt, which is relatively less affected by additional factors and has small tension fluctuations.

[0029] Optionally, in the tape supply side detection mechanism, the force transmission component is located above the force sensor, and the force sensor is a pressure sensor or a tension-pressure sensor; in the tape take-up side detection mechanism, the force transmission component is located below the force sensor, and the force sensor is a tension sensor or a tension-pressure sensor; or, in the tape supply side detection mechanism, the force transmission component is located below the force sensor, and the force sensor is a tension sensor or a tension-pressure sensor; in the tape take-up side detection mechanism, the force transmission component is located above the force sensor, and the force sensor is a pressure sensor or a tension-pressure sensor.

[0030] Optionally, in the wafer edge polishing device as described above, the polishing module also includes a follower pressure roller and a traction assembly sequentially arranged between the belt taking-up guide wheel assembly and the belt taking-up detection mechanism, and the polishing belt is also wound around the follower pressure roller and the traction assembly.

[0031] Optionally, in the wafer edge polishing device as described above, the tape supply mechanism includes a tape supply motor and a tape supply winding wheel driven and rotated by the tape supply motor; the tape take-up mechanism includes a tape take-up motor and a tape take-up winding wheel driven and rotated by the tape take-up motor, and the two ends of the polishing tape are respectively connected to the tape supply winding wheel and the tape take-up winding wheel.

[0032] Optionally, in the wafer edge polishing device as described above, the tape supply guide wheel assembly includes a plurality of tape supply guide wheels arranged in sequence, and the polishing tape is wound around the plurality of tape supply guide wheels in sequence.

[0033] Optionally, in the wafer edge polishing device as described above, the belt take-up guide wheel assembly includes a plurality of belt take-up guide wheels arranged in sequence, and the polishing belt is wound around the plurality of belt take-up guide wheels in sequence.

[0034] Optionally, in the wafer polishing device as described above, the wafer polishing device further includes a frame, and the polishing module and the detection mechanism are arranged on the frame.

[0035] According to a second aspect of the present invention, a wafer edge polishing system is provided, comprising a processing controller and a tension controller. The wafer edge polishing system also comprises the wafer edge polishing device described above. The processing controller is connected to the force sensor signal, and the processing controller is used to receive the pressure signal sent by the force sensor for processing and displaying the tension of the polishing belt.

[0036] Optionally, in the wafer edge polishing system as described above, the processing controller is also electrically connected to the tension controller and sends instructions to the tension controller to control the speed of the motor of the tape supply mechanism and / or the motor of the tape take-up mechanism, and / or control the position of the movable guide wheel, thereby controlling the tension of the polishing tape.

[0037] According to a third aspect of the present invention, a method for detecting tension of a polishing belt is provided, using the above-mentioned wafer side polishing device or the above-mentioned wafer side polishing system, the tension detection method comprising:

[0038] When the polishing module and the detection mechanism are not wound with the polishing belt, the force value of the force transmission member on the force sensor is detected by the force sensor and recorded as F 0 ;

[0039] When the polishing belt is wound around the polishing module and the detection mechanism and / or the side polishing process is performed, the polishing belt generates a force on the force transmission member, and the force value of the force transmission member on the force sensor is detected by the force sensor and recorded as F t ;

[0040] The tension value of the polishing belt is calculated as |F 0 -F t ∣ / 2.

[0041] By adopting the above technical solution, online detection of the tension of the polishing belt can be achieved, and the detected tension is the actual tension of the polishing belt, which is relatively less affected by additional factors and has small tension fluctuations, making it easier to complete the precise control of the wafer edge polishing process.

[0042] According to a fourth aspect of the present invention, a method for controlling the tension of a polishing belt is provided, comprising:

[0043] Using the tension detection method described above to detect the tension value of the polishing belt;

[0044] The rotation speed of the motor of the tape supply mechanism and / or the motor of the tape take-up mechanism is adjusted according to the tension value, thereby controlling the tension of the polishing tape.

[0045] Further optionally, the detection mechanisms are respectively arranged on both sides of the pressure feeding assembly, and the detection mechanisms on both sides are recorded as a tape supply side detection mechanism and a tape take-up side detection mechanism;

[0046] Adjusting the rotation speed of the motor of the tape supply mechanism according to the tension value detected by the tape supply side detection mechanism;

[0047] The rotation speed of the motor of the belt taking-up mechanism is adjusted according to the tension value detected by the belt taking-up side detection mechanism.

[0048] According to a fifth aspect of the present invention, there is provided a method for controlling the tension of a polishing belt, comprising:

[0049] Using the tension detection method described above to detect the tension value of the polishing belt;

[0050] The position of the first guide wheel and / or the second guide wheel is adjusted according to the tension value, thereby changing the distance between at least one guide wheel and the force transmission member to adjust the tension of the polishing belt, thereby controlling the tension of the polishing belt.

[0051] Further optionally, the detection mechanisms are respectively arranged on both sides of the pressure feeding assembly, and the detection mechanisms on both sides are recorded as a tape supply side detection mechanism and a tape take-up side detection mechanism;

[0052] Adjusting the position of the first guide wheel and / or the second guide wheel in the tape supply side detection mechanism according to the tension value detected by the tape supply side detection mechanism;

[0053] The position of the first guide wheel and / or the second guide wheel in the tape-receiving side detection mechanism is adjusted according to the tension value detected by the tape-receiving side detection mechanism.

[0054] By adopting the above technical solution, the tension adjustment and control of the polishing belt is more convenient and more accurate, which greatly reduces the control difficulty of the wafer edge polishing process.

[0055] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0056] The wafer edge polishing device of the present application uses the force generated by the polishing belt on the force transmission component, and then uses the force sensor to sense the difference in force between the force transmission component and the force sensor, to perform direct online detection of the tension of the polishing belt, which helps to accurately control the tension of the polishing belt, greatly reducing the difficulty of controlling the wafer edge polishing process, and thus maintaining a basically constant tension of the polishing belt during edge polishing to ensure the uniformity of edge polishing, and is less likely to produce adverse stripe patterns on the edge of the wafer, thereby ensuring the edge polishing effect.

[0057] The polishing belt tension detection of the wafer edge polishing device of the present application eliminates a large number of influencing factors in the existing measurement method (force control motor reading tension), and the detected tension is closer to the actual tension of the polishing belt, and the measured value is almost completely close to the true value. In addition, since the influencing factors are small, the tension fluctuation is small, further reducing the difficulty of process control. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0059] Figure 1 It is a structural schematic diagram of a wafer edge polishing device in the prior art;

[0060] Figure 2 A schematic structural diagram of a wafer edge polishing device according to an embodiment of the present application;

[0061] Figure 3 for Figure 2 A schematic diagram of the enlarged structure at A in the middle;

[0062] Figure 4 A structural block diagram of a wafer edge polishing system according to an embodiment of the present application;

[0063] Figure 5 A flowchart of a wafer edge polishing system according to an embodiment of the present application;

[0064] Figure 6 for Figure 5 A specific flow chart of step S1 in the workflow shown;

[0065] Reference numerals:

[0066] 1. Tape supply motor; 2. Tape supply reel; 3. Tape supply guide wheel; 4. Polishing tape; 5. Pressure feed assembly; 6. Wafer; 7. Traction assembly; 8. Follow-up pressure roller; 9. Take-up reel; 10. Take-up motor; 11. First guide wheel; 12. Fixed pulley guide wheel; 13. Fixed pulley bracket; 14. Force sensor; 15. Second guide wheel; 16. Mounting plate; 17. Take-up guide wheel

[0067] 100. Wafer side polishing device; 200. Processing controller; 300. Tension controller. DETAILED DESCRIPTION

[0068] The wafer edge polishing device of the prior art, such as Figure 1 As shown, the detection of the tension of the polishing belt is mainly through the force control motor reading the tension (motor torque on the supply side and / or the take-up side). However, in this way, the torque output by the motor is greatly affected by external factors, and the torque collected by the motor is relatively volatile, which makes it impossible to accurately detect and control the tension of the polishing belt, greatly increasing the control difficulty of the wafer edge polishing process, and the edge polishing effect is difficult to guarantee. In the prior art, there is no solution that can realize online detection of the tension of the polishing belt.

[0069] The present application sets a detection mechanism on the side of the pressure feed assembly 5, and the detection mechanism includes a fixed force sensor 14 and a force transmission member arranged on the force sensor 14. The force sensor 14 is used to detect the force acting on the force transmission member. The polishing belt is also wound on the force transmission member and can generate force on the force transmission member. The force sensor 14 records the pressure value of the force transmission member on the force sensor 14 when the polishing belt 4 is not wound and the force value of the force transmission member on the force sensor 14 after the polishing belt 4 is wound, and then calculates the tension of the polishing belt 4, which can realize direct online detection of the tension of the polishing belt 4 and eliminate a large number of influencing factors in the existing tension detection method (reading the tension through a force control motor). The detection method of the present application basically has a measurement value that is almost completely close to the true value, except for the friction of the guide wheel and the error of the force sensor, which greatly reduces the control difficulty of the wafer edge polishing process.

[0070] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in the field based on the embodiments in the embodiments of the present invention should fall within the scope of protection of the embodiments of the present invention.

[0071] See also Figure 2-Figure 3 The wafer edge polishing device shown includes a frame, a polishing belt 4 and a polishing module arranged on the frame, the polishing module includes a tape supply mechanism, a tape supply guide wheel assembly, a pressure feed assembly 5, a traction assembly 7, a follower pressure roller 8, a tape take-up guide wheel assembly and a tape take-up mechanism, the tape supply mechanism, the tape supply guide wheel assembly, the pressure feed assembly 5, the traction assembly 7, the follower pressure roller 8, the tape take-up guide wheel assembly and the tape take-up mechanism are arranged in sequence, the two ends of the polishing belt 4 are respectively connected to the tape supply mechanism and the tape take-up mechanism, and the polishing belt 4 is wound around the tape supply guide wheel assembly, the pressure feed assembly 5, the traction assembly 7, the follower pressure roller 8 and the tape take-up guide wheel assembly in sequence.

[0072] The wafer 6 and the pressure feed assembly 5 are arranged correspondingly, and the wafer 6 and the pressure feed assembly 5 are respectively located on both sides of the polishing belt 4. When the wafer 6 is polished, the wafer 6 rotates in the horizontal direction.

[0073] The tape supply mechanism includes a tape supply motor 1 and a tape supply winding wheel 2 driven and rotated by the tape supply motor 1, and the tape take-up mechanism includes a tape take-up motor 10 and a tape take-up winding wheel 9 driven and rotated by the tape take-up motor 10. The two ends of the polishing tape 4 are respectively connected to the tape supply winding wheel 2 and the tape take-up winding wheel 9.

[0074] The tape supply guide wheel assembly includes a plurality of tape supply guide wheels 3 arranged in sequence, and the polishing belt 4 is wound around the plurality of tape supply guide wheels 3 in sequence; the tape take-up guide wheel assembly includes a plurality of tape take-up guide wheels 17 arranged in sequence, and the polishing belt 4 is also wound around the plurality of tape take-up guide wheels 17 in sequence.

[0075] In order to realize the online direct detection of the tension of the polishing belt 4, Figure 2 It can be seen that the wafer edge polishing device also includes detection mechanisms arranged on the opposite sides of the pressure feeding assembly 5, and the detection mechanisms on both sides are recorded as supply side detection mechanisms and take-up side detection mechanisms. In this example, the supply side detection mechanism is arranged between the supply guide wheel 3 and the pressure feeding assembly 5, and the take-up side detection mechanism is arranged between the pressure feeding assembly 5 and the traction assembly 7. In the initial state of the wafer edge polishing process, the polishing belt between the supply side detection mechanism and the take-up side detection mechanism is made to be perpendicular to the surface of the wafer 6 as much as possible, that is, parallel to the center axis of the wafer 6.

[0076] In other embodiments, the supply side detection mechanism may also be set at any position between the supply winding wheel 2 and the pressure feeding assembly 5, and the take-up side detection mechanism may also be set at any position between the pressure feeding assembly 5 and the take-up winding wheel 9.

[0077] See also Figure 2 The supply side detection mechanism and the take-up side detection mechanism each include a mounting plate 16 fixedly mounted on the frame, a force sensor 14 fixedly mounted on the mounting plate 16, a force transmission member mounted on the force sensor 14, and a first guide wheel 11 and a second guide wheel 15 mounted on both sides of the force transmission member. The force sensor 14 is used to detect the force acting on the force transmission member. Figure 2 It can be seen that the winding order of the polishing belt 4 is as follows: the polishing belt 4 is sequentially wound around multiple tape supply guide rollers 3, the first guide roller 11 in the tape supply side detection mechanism, the force transmission component in the tape supply side detection mechanism, the second guide roller 15 in the tape supply side detection mechanism, the pressure feeding assembly 5, the second guide roller 15 in the tape taking-up side detection mechanism, the force transmission component in the tape taking-up side detection mechanism, the first guide roller 11 in the tape taking-up side detection mechanism, the traction assembly 7, the follow-up pressure roller 8 and multiple tape taking-up guide rollers 17.

[0078] In some embodiments, see Figure 3 The force transmission component is a fixed pulley arranged on the force sensor 14, and the fixed pulley includes a fixed pulley bracket 13 fixedly arranged on the force sensor 14 and a fixed pulley guide wheel 12 rotatably arranged on the fixed pulley bracket 13 around its own axis. Specifically, the fixed pulley guide wheel 12 has an axle, and the axle is rotatably mounted on the fixed pulley bracket 13. The fixed pulley bracket 13 is fixedly connected to the force sensor 14 by screws and screw holes.

[0079] The polishing belt 4 is wound around the fixed pulley guide wheel 12. When working normally, the polishing belt 4 will inevitably generate a force on the fixed pulley guide wheel 12 due to its own tension. The fixed pulley principle is used to convert the tension in the polishing belt 4 into an external force on the fixed pulley guide wheel 12, and the force sensor 14 senses the change in the force of the fixed pulley guide wheel 12 on the force sensor 14, thereby calculating the tension of the polishing belt 4.

[0080] Depend on Figure 2 As can be seen in the figure, for the supply side detection mechanism, the force sensor 14 is located below the fixed pulley guide wheel 12, and the polishing belt 4 exerts an upward force on the fixed pulley guide wheel 12; while for the take-up side detection mechanism, the force sensor 14 is located above the fixed pulley guide wheel 12, and the polishing belt 4 exerts a downward force on the fixed pulley guide wheel 12. The force sensors of the supply side detection mechanism and the take-up side detection mechanism are both tension and pressure sensors.

[0081] The supply side detection mechanism and the take-up side detection mechanism are symmetrically arranged, and by locating the force sensor in the supply side detection mechanism below the fixed pulley guide wheel, and the force sensor in the take-up side detection mechanism above the fixed pulley guide wheel, the force sensor of the supply side detection mechanism and the force sensor of the take-up detection mechanism can be arranged close to each other, so that the structure of the supply side detection mechanism and the take-up side detection mechanism are compact and space-saving, and the addition of the two will not occupy too much space of the original equipment, and the original equipment does not need to be significantly modified; and such an arrangement can also prevent the polishing belt 4 from contacting and interfering with the force sensor 14 or the mounting plate 16 when it shakes.

[0082] In this example, the principle of using a tension sensor to detect the tension of the polishing belt by the supply side detection mechanism is as follows: when the fixed pulley guide wheel is not wound with the belt, due to the weight of the fixed pulley (including the fixed pulley guide wheel and the fixed pulley bracket), pressure is applied to the tension sensor, and the elastic sensitive element of the tension sensor produces a slight deformation. At this time, the tension sensor can detect the initial pressure (that is, the initial force of the fixed pulley on the tension sensor, recorded as F 0 , and F 0 =G, where G is the gravity value of the fixed pulley); when the fixed pulley is wound with a belt and polished, the polishing belt will generate an upward force on the fixed pulley, which can offset part of the weight of the fixed pulley, causing the pressure applied by the fixed pulley to the tension pressure sensor to decrease, and the deformation of the tension pressure sensor to decrease. At this time, the tension pressure sensor detects a pressure value F t , and F t =G-2F 张 , so the tension of the polishing belt is F 张 =(F 0 -F t ) / 2.

[0083] The principle of using a tension sensor to detect the tension of the polishing belt by the belt-collecting side detection mechanism is as follows: when the fixed pulley guide wheel is not wound with the belt, due to the weight of the fixed pulley (including the fixed pulley guide wheel and the fixed pulley bracket), a tension is applied to the tension sensor (the tension value is equal to the gravity G of the fixed pulley). At this time, the initial tension detected by the tension sensor (i.e., the initial force of the fixed pulley on the tension sensor, recorded as F 0 , and F 0 = G); when the fixed pulley is wound with a belt and polished, the polishing belt will exert a downward force on the fixed pulley, increasing the tension value of the tension pressure sensor, and the deformation of the tension pressure sensor increases. At this time, the tension pressure sensor detects the tension value F t , and F t =G+2F 张 , so the tension of the polishing belt is F 张 =(F t -F 0 ) / 2.

[0084] In some other embodiments, the force sensor in the detection mechanism on the supply side may also be a pressure sensor, and the force sensor in the detection mechanism on the take-up side may also be a tension sensor.

[0085] In other embodiments, for the tape supply side detection mechanism, the force sensor may also be located above the fixed pulley guide wheel, and the force sensor may be a tension sensor or a tension pressure sensor; for the tape collection side detection mechanism, the force sensor may also be located below the fixed pulley guide wheel, and the force sensor may be a pressure sensor or a tension pressure sensor.

[0086] See also Figure 2 The first guide wheel 11 and the second guide wheel 15 in the tape receiving side detection mechanism and the tape supply side detection mechanism are used to adjust the angle between the part of the polishing belt 4 between the first guide wheel 11 and the fixed pulley and the part of the polishing belt 4 between the second guide wheel 15 and the fixed pulley, and make the angle as close to 0° as possible, so that the two parts of the polishing belt 4 are arranged in parallel, and the angle of the polishing belt 4 is prevented from affecting the measurement of the tension, so as to ensure the measurement accuracy. Furthermore, the extension line of the force of the polishing belt 4 on the fixed pulley is parallel to the two parts of the polishing belt 4.

[0087] In the edge throwing device, the polishing tape transmission system composed of a plurality of supply guide wheels 3 and take-up guide wheels 17 improves the stability of the polishing tape tension to a certain extent, but when the tension is adjusted by, for example, the torque / rotation speed of the motor of the supply mechanism and / or the motor of the take-up mechanism, the adjustment result may not be transmitted to the wafer polishing in time, affecting the effect of wafer edge polishing. In view of the narrow space of the edge throwing device, in some embodiments, the position of at least one of the first guide wheel 11 and the second guide wheel 15 is adjustable, that is, the first guide wheel 11 and / or the second guide wheel 15 are set as movable guide wheels, so that the first guide wheel 11 and the second guide wheel 15 can be used not only to adjust the angle of the polishing tape 4, but also to change the tension of the polishing tape 4 to adjust the tension of the polishing tape 4.

[0088] In one embodiment, the rotation axes of the first guide wheel 11 and the second guide wheel 15 are connected to a position adjustment device, and the position adjustment device is used to make the rotation axes of the first guide wheel 11 and the second guide wheel 15 move upward and downward synchronously, and / or change positions synchronously in opposite directions. In one embodiment, a slide groove is provided on the mounting frame of the guide wheel assembly, and two bearing assemblies that can move along the slide groove are arranged in the slide groove. The rotation axes of the first guide wheel 11 and the second guide wheel 15 are respectively engaged in one of the bearing assemblies, so that the first guide wheel 11 and the second guide wheel 15 can move along the slide groove while rotating. Preferably, the slide groove is two and is symmetrically arranged in an "eight" shape with the axial plane where the wheel axle of the fixed pulley guide wheel 12 is located. The position adjustment device connects the rotation axes of the first guide wheel 11 and the second guide wheel 15, and drives the first guide wheel 11 and the second guide wheel 15 to move toward each other synchronously along the corresponding slide groove in an upward and opposite moving trajectory, and move away from each other in a downward and opposite moving trajectory. Preferably, during the movement, the angle change range between the partial polishing belt 4 located between the first guide wheel 11 and the force transmission member and the partial polishing belt 4 located between the second guide wheel 15 and the force transmission member is -5 to 5°, the vertical or horizontal movement distance of the first guide wheel 11 or the second guide wheel 15 is less than 1 cm, and the angle range between the slide groove and the horizontal plane is 30° to 60°.

[0089] According to the embodiment of the present invention, the tension is adjusted directly at the tension detection mechanism, so that the adjustment result is quickly and accurately transmitted to the wafer polishing part, effectively maintaining the stability of the polishing belt tension at the wafer polishing part, and improving the side polishing effect. At the same time, by setting the slide groove and synchronously controlling the first and second guide wheels in this embodiment, the space occupation requirement is reduced, and the tension has a sufficiently large adjustment range, and the control is simple and efficient.

[0090] The tension detection of the polishing tape 4 by the supply side detection mechanism is as follows: (1) when the polishing module, the supply side detection mechanism and the take-up side detection mechanism are not winding the polishing tape 4, the force sensor 14 in the supply side detection mechanism detects the force value of the fixed pulley guide wheel 12 on the force sensor 14 and records it as F 0 (2) When the polishing belt 4 is wound around the polishing module, the supply side detection mechanism and the take-up side detection mechanism and the side polishing process is performed, the polishing belt 4 exerts a force on the fixed pulley guide wheel 12 in the supply side detection mechanism. The force value of the fixed pulley guide wheel 12 on the force sensor 14 is detected by the force sensor 14 in the supply side detection mechanism and recorded as F t ; (3) Calculate the tension value of the polishing belt 4 as (F 0 -F t ) / 2.

[0091] The tension detection of the polishing belt 4 by the take-up side detection mechanism is caused by gravity and the installation direction of the force sensor. When the polishing module, the supply side detection mechanism and the take-up side detection mechanism are not winding the polishing belt 4, the value F of the force sensor in the take-up side detection mechanism is 0 will be smaller than the value F of the force sensor in the take-up side detection mechanism after the polishing tape 4 is wound around the polishing tape 4 in the polishing module, the supply side detection mechanism and the take-up side detection mechanism. t Therefore, the tension value of the polishing belt 4 calculated on the take-up side is (F t -F 0 ) / 2.

[0092] When winding the polishing belt 4 to detect the tension, first adjust the installation position of the first guide wheel 11 and the second guide wheel 15 to ensure that the part of the polishing belt between the first guide wheel 11 and the fixed pulley remains parallel to the part of the polishing belt between the second guide wheel 15 and the fixed pulley to prevent the polishing belt 4 from having an angle that affects the tension measurement.

[0093] The supply side detection mechanism is arranged between the supply guide wheel 3 and the pressure feed assembly 5, and the take-up side detection mechanism is arranged between the traction assembly 7 and the pressure feed assembly 5. Both the supply side detection mechanism and the take-up side detection mechanism are arranged close to both sides of the wafer 6. The measured value is closest to the tension of the polishing belt 4 acting on the wafer 6, and the detection eliminates a large number of influencing factors in the existing detection method. Except for the error of the friction force of the guide wheel and the force sensor, the measured value is almost completely close to the real value of the tension of the polishing belt. There are relatively few additional influencing factors, and the tension fluctuation is small, which greatly reduces the process control difficulty of wafer edge polishing.

[0094] In actual working conditions, when winding the tape, the tension value of the polishing tape can be roughly adjusted through the tension values ​​detected by the supply side detection mechanism and the take-up side detection mechanism; and when performing the edge polishing process, the tension of the polishing tape can be fine-tuned in real time through the tension values ​​detected by the supply side detection mechanism and the take-up side detection mechanism to ensure that the tension of the polishing tape remains basically constant during edge polishing, so as to ensure the uniformity of edge polishing and prevent unfavorable stripe patterns from being generated at the edge of the wafer. Especially when the ratio of the wafer size to the width of the polishing belt is relatively large, the edge of the wafer is more sensitive to the change of tension during edge polishing. If the tension of the polishing belt changes repeatedly, it is easier to produce unfavorable stripe patterns at the edge of the wafer. For example, when using a polishing belt of a commonly used width (35mm) to edge polish wafers of different sizes, a 12-inch wafer (300mm in diameter) is more sensitive to the change of the tension of the polishing belt than a 6-inch or 8-inch wafer. Traditional control and detection methods will cause inaccurate control and high delay, and the tension is difficult to stabilize after repeated changes. For a 12-inch wafer, it is easier to produce unfavorable stripe patterns at the edge of the wafer. The edge polishing device of the wafer of the embodiment of the present application can control the tension of the polishing belt more accurately and with lower control difficulty, which helps to maintain a basically constant tension of the polishing belt during edge polishing to ensure the uniformity of edge polishing and the effect of edge polishing.

[0095] See also Figure 4 An embodiment of the present application provides a wafer edge polishing system, including a processing controller 200, the above-mentioned wafer edge polishing device 100 and a tension controller 300. The processing controller 200 is connected to the force sensors 14 on both sides by signals. The processing controller 200 is used to receive the pressure signal sent by the force sensor 14 for processing and displaying the tension of the polishing belt 4.

[0096] The processing controller 200 is also electrically connected to the tension controller 300 and sends instructions to the tension controller 300 to control the rotation speed of the take-up motor 10 of the take-up mechanism and the supply motor 1 of the supply mechanism, thereby controlling the tension of the polishing belt 4 .

[0097] The specific working process of the wafer edge polishing system of the embodiment of the present application is described below:

[0098] S1. Detect the tension of the polishing belt

[0099] S11, complete the installation of the force sensor and fixed pulley on the supply side / take-up side, and record the current reading F of the force sensor on the supply side / take-up side 0 .

[0100] Specifically, after the force sensors and fixed pulleys in the supply side detection mechanism and the take-up side detection mechanism are installed, the force sensors 14 in the supply side detection mechanism and the take-up side detection mechanism respectively record the current readings F in the supply side detection mechanism and the take-up side detection mechanism. 0 ;

[0101] S12, completing the installation of the first guide wheel and the second guide wheel on the supply side / take-up side, winding the tape, and adjusting the installation positions of the first guide wheel and the second guide wheel on the supply side / take-up side.

[0102] Specifically, the first guide wheel 11 and the second guide wheel 15 in the supply side detection mechanism and the take-up side detection mechanism are installed, and the polishing belt 4 is installed in sequence, and then the installation positions of the first guide wheel 11 and the second guide wheel 15 in the supply side detection mechanism and the take-up side detection mechanism are adjusted to ensure that the part of the polishing belt 4 between the first guide wheel 11 and the fixed pulley in the supply side detection mechanism and the take-up side detection mechanism and the part of the polishing belt 4 between the second guide wheel 15 and the fixed pulley are parallel to each other;

[0103] S13, turn on the motor on the supply side / take-up side, and record the current value F of the force sensor on the supply side / take-up side t , the tension on the supply side is calculated to be (F 0 -F t ) / 2, the tension on the take-up side is (F t -F 0 ) / 2.

[0104] Specifically, the supply motor 1 and the take-up motor 10 are turned on to make the polishing belt 4 run. When the polishing belt 4 works normally, the tension of the polishing belt 4 generates an upward force on the fixed pulley of the supply side detection mechanism and a downward force on the fixed pulley of the take-up side detection mechanism. The current value F of the force sensor 14 in the supply side detection mechanism and the take-up side detection mechanism is recorded. t ;

[0105] According to the working principle of the fixed pulley, the polishing belt tension on the supply side is calculated as (F 0 -F t ) / 2, and the tension calculation result of the polishing belt on the take-up side is (F t -F 0 ) / 2, the tension value of the polishing belt on the supply side is basically the same as the tension value of the polishing belt on the take-up side.

[0106] S2. Adjust and control the tension of the polishing belt

[0107] The calculated tension value (F 0 -F t ) / 2 is compared with the tension value preset in the processing controller to adjust the speed of the tape supply motor 1;

[0108] The calculated tension value (F t -F 0) / 2 is compared with the tension value preset in the processing controller, the rotation speed of the take-up motor 10 is adjusted, and then the actual tension of the polishing belt 4 is adjusted and controlled.

[0109] The wafer edge polishing device of the embodiment of the present application is used to edge polish the wafer. Compared with the wafer edge polishing device in the prior art, the tension detection and control of the polishing belt 4 are more convenient, and the tension detection value is more accurate, which greatly reduces the difficulty of process control of wafer edge polishing. The tension control is more accurate and the delay is low, ensuring that the tension of the polishing belt is basically constant during edge polishing, so as to ensure the uniformity of edge polishing and not easily produce unfavorable stripe patterns on the edge of the wafer.

[0110] In some embodiments, the tension control of the polishing belt 4 can also be carried out by adjusting the distance between the first guide wheel 11 and the second guide wheel 15 in the supply side detection mechanism and the fixed pulley according to the supply side tension value detected by the supply side detection mechanism, and adjusting the distance between the first guide wheel 11 and the second guide wheel 15 in the take-up side detection mechanism and the fixed pulley according to the take-up side tension value of the take-up side detection mechanism, thereby controlling the tension of the polishing belt 4.

[0111] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0112] In addition, in the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection of two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0113] The above implementation methods are only used to illustrate the embodiments of the present invention, and are not limitations of the embodiments of the present invention. Ordinary technicians in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the embodiments of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the embodiments of the present invention. The patent protection scope of the embodiments of the present invention should be defined by the claims.

Claims

1. A wafer edge polishing device, characterized in that: It comprises a polishing module and a polishing belt (4), wherein the polishing module comprises a belt supply mechanism, a belt supply guide wheel assembly, a pressure feeding assembly (5), a belt take-up guide wheel assembly and a belt take-up mechanism; The tape supply mechanism, tape supply guide wheel assembly, pressure feed assembly (5), tape take-up guide wheel assembly and tape take-up mechanism are arranged in sequence, the two ends of the polishing tape (4) are respectively connected to the tape supply mechanism and the tape take-up mechanism, and the polishing tape (4) is wound around the tape supply guide wheel assembly, the pressure feed assembly (5) and the tape take-up guide wheel assembly in sequence; The wafer side polishing device also includes a detection mechanism arranged on at least one side of the pressure feeding assembly; The detection mechanism comprises a force sensor (14) and a force transmission component arranged on the force sensor (14), wherein the force sensor (14) is used to detect the force applied to the force transmission component, and the polishing belt (4) is also wound around the force transmission component, and the tension of the polishing belt (4) can change the force.

2. The wafer polishing device according to claim 1, characterized in that: The detection mechanism also includes a first guide wheel (11) and a second guide wheel (15) arranged on both sides of the force transmission member, and the polishing belt (4) is arranged to pass around the first guide wheel (11), the force transmission member and the second guide wheel (15) in sequence.

3. The wafer polishing device according to claim 2, characterized in that: The first guide wheel (11) and / or the second guide wheel (15) are arranged in a position-adjustable manner, so that the tension of the polishing belt (4) can be controlled by changing the position.

4. The wafer side polishing device according to claim 3, characterized in that: The rotation axes of the first guide wheel (11) and the second guide wheel (15) are connected to a position adjustment device, and the position adjustment device is used to make the rotation axes of the first guide wheel (11) and the second guide wheel (15) move upward and downward synchronously, and / or change positions synchronously towards and in opposite directions.

5. The wafer polishing device according to claim 4, characterized in that: The synchronously changing positions in opposite directions and in opposite directions makes the angle between the part of the polishing belt (4) between the first guide wheel (11) and the force transmission member and the part of the polishing belt (4) between the second guide wheel (15) and the force transmission member change within a range of -5 to 5 degrees.

6. The wafer polishing device according to claim 1, characterized in that: The force sensor (14) is fixedly arranged, and the force transmission component is a fixed pulley arranged on the force sensor (14).

7. The wafer polishing device according to claim 6, characterized in that: The detection mechanism also includes a fixed mounting plate (16), the force sensor (14) is fixedly mounted on the mounting plate (16), the fixed pulley includes a fixed pulley bracket (13) mounted on the force sensor (14) and a fixed pulley guide wheel (12) mounted on the fixed pulley bracket (13) and rotatable around its own axis, and the polishing belt (4) is wound around the fixed pulley guide wheel (12).

8. The wafer edge polishing device according to any one of claims 1 to 7, characterized in that: The force sensor (14) is a tension sensor, a pressure sensor or a tension-pressure sensor.

9. The wafer edge polishing device according to any one of claims 1 to 7, characterized in that: The detection mechanisms are respectively arranged on both sides of the pressure feeding assembly (5).

10. The wafer polishing device according to claim 9, characterized in that: The detection mechanisms on both sides are denoted as a supply side detection mechanism and a take-up side detection mechanism. The supply side detection mechanism is arranged between the supply guide wheel assembly and the pressure feed assembly (5); the take-up side detection mechanism is arranged between the pressure feed assembly (5) and the take-up guide wheel assembly.

11. The wafer polishing device according to claim 10, characterized in that: In the tape supply side detection mechanism, the force transmission component is located above the force sensor (14), and the force sensor is a pressure sensor or a tension pressure sensor; in the tape take-up side detection mechanism, the force transmission component is located below the force sensor (14), and the force sensor is a tension sensor or a tension pressure sensor; or, in the tape supply side detection mechanism, the force transmission component is located below the force sensor (14), and the force sensor is a tension sensor or a tension pressure sensor; in the tape take-up side detection mechanism, the force transmission component is located above the force sensor (14), and the force sensor is a pressure sensor or a tension pressure sensor.

12. The wafer polishing device according to claim 1, characterized in that: The tape supply mechanism comprises a tape supply motor (1) and a tape supply reel (2) driven to rotate by the tape supply motor (1); the tape take-up mechanism comprises a tape take-up motor (10) and a tape take-up reel (9) driven to rotate by the tape take-up motor (10), and the two ends of the polishing tape (4) are respectively connected to the tape supply reel (2) and the tape take-up reel (9); and / or, The tape supply guide wheel assembly comprises a plurality of tape supply guide wheels (3) arranged in sequence, and the polishing tape (4) is wound around the plurality of tape supply guide wheels (3) in sequence; and / or, The belt guide wheel assembly comprises a plurality of belt guide wheels (17) arranged in sequence, and the polishing belt (4) is wound around the plurality of belt guide wheels (17) in sequence; and / or, The wafer edge polishing device also includes a frame, and the polishing module and the detection mechanism are arranged on the frame.

13. A wafer edge polishing system, comprising a processing controller and a tension controller, characterized in that: The wafer edge polishing system also includes a wafer edge polishing device according to any one of claims 1 to 12, wherein the processing controller is connected to the force sensor (14) signal, and the processing controller is used to receive the pressure signal sent by the force sensor (14) for processing and displaying the tension of the polishing belt (4); the processing controller also controls the tension controller to control the tension of the polishing belt (4).

14. A method for detecting tension of a polishing belt, using the wafer edge polishing device according to any one of claims 1 to 12 or the wafer edge polishing system according to claim 13, characterized in that: The tension detection method comprises: When the polishing module and the detection mechanism are not winding the polishing belt, the force value of the force transmission component on the force sensor (14) is detected by the force sensor (14) and recorded as F0; When the polishing belt is wound around the polishing module and the detection mechanism and / or the side polishing process is performed, the polishing belt generates a force on the force transmission member, and the force value of the force transmission member on the force sensor (14) is detected by the force sensor (14) and recorded as F t ; The tension value of the polishing belt is calculated as |F0-F t ∣ / 2.

15. A method for controlling the tension of a polishing belt, characterized in that: The tension control method comprises: S1. Detecting the tension value of the polishing belt (4) using the tension detection method described in claim 14; S2. Control the tension of the polishing belt by any of the following methods: Method 1: adjusting the rotation speed of the motor of the tape supply mechanism and / or the motor of the tape take-up mechanism according to the tension value, thereby controlling the tension of the polishing tape (4); Method 2: adjusting the position of the first guide wheel (11) and / or the second guide wheel (15) according to the tension value, thereby controlling the tension of the polishing belt (4).

16. The tension control method according to claim 15, characterized in that: The detection mechanisms are respectively arranged on both sides of the pressure feeding assembly (5), and the detection mechanisms on both sides are recorded as a tape supply side detection mechanism and a tape take-up side detection mechanism; In the first mode, the rotation speed of the motor of the tape supply mechanism is adjusted according to the tension value detected by the tape supply side detection mechanism; adjusting the rotation speed of the motor of the take-up mechanism according to the tension value detected by the take-up side detection mechanism; and / or, In the second method, the position of the first guide wheel (11) and / or the second guide wheel (15) in the tape supply side detection mechanism is adjusted according to the tension value detected by the tape supply side detection mechanism; The position of the first guide wheel (11) and / or the second guide wheel (15) in the belt-receiving side detection mechanism is adjusted according to the tension value detected by the belt-receiving side detection mechanism.

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