Device and method for achieving micron-sized repeated precision positioning through visual detection and compensation

Abstract

The invention relates to the related technical field of semiconductor manufacturing equipment, in particular to a device and method for achieving micron-scale repeated precision positioning through visual inspection and compensation, the device comprises a base, an adsorption mechanism, a light source plate and an edge searching positioning camera, a detection table top is fixedly installed on the upper surface of the base through a vertical rod, and a center groove is formed in the detection table top; a first bracket and a second bracket are fixedly mounted on the base, a transverse driving module is mounted on the first bracket, and a total driving module is mounted on the second bracket; a 2 million-pixel camera is used for replacing a high-precision laser sensor, the problem of compatible detection of transparent and opaque objects to be detected is solved, the detection range is enlarged to 22 mm, the cost is reduced, micron-order repeated precision is achieved, a stepping motor is used for replacing a high-cost DD motor, and the detection efficiency is improved. A vision algorithm is used for compensating the problems of rotation concentricity deviation and positive and negative rotation back clearance of the rotor axis of the stepping motor, and micron-order repetition precision is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field related to semiconductor manufacturing equipment, and in particular to equipment and methods for visual inspection and compensation to achieve micron-level repeatable precision positioning. Background Art

[0002] Modern semiconductor manufacturing involves multiple complex process steps, such as photolithography, etching, ion implantation, etc. Each step requires precise alignment to ensure the performance and reliability of the final product; The existing Chinese patent document with announcement number CN201910174605.5 discloses a special positioning processing table for semiconductor wafer processing, and its scheme includes a support frame, a processing plate, a fixing rod, an electric control box, a controller, a power interface, a connection port, a positioning device and an adjustment device. A processing plate is arranged on the top of the support frame, and the lower end of the inner side of the support frame is fixedly connected to the fixing rod. A positioning device is arranged on the front end of the top of the processing plate, and an adjustment device is arranged on the back of the positioning device. An electric control box is fixed to the right end of the top of the fixing rod, and the front end of the right side of the electric control box is fixedly connected to the controller by strong glue. A power interface is arranged at the rear end of the controller, and the left and right ends of the power interface are fixed to the electric control box by bolts, and a connection port is arranged on the top of the power interface. The positioning device includes a top plate, a fixing device, a bottom plate, a slide groove, a first roller, a first movable rod, a second movable rod, an electric push rod, a first cross bar, a second cross bar, a third cross bar and a second roller; However, the above technical solution has low alignment accuracy and insufficient adaptability due to the sensor alignment technology (the sensor may be sensitive to the surface characteristics of different materials (such as reflection and transparency), resulting in inaccurate alignment in some cases), and the sensor system requires more maintenance and calibration, which increases the long-term operation and maintenance costs. Therefore, the present invention proposes a device and method for visual detection and compensation to achieve micron-level repeatability positioning to solve the above problems. Summary of the invention

[0003] The object of the present invention is to provide a device and method for visual inspection and compensation to achieve micron-level repeatability positioning, so as to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above object, the present invention provides the following technical solution: a device for visual inspection and compensation to achieve micron-level repeatability positioning, comprising: A base, wherein a detection table is fixedly mounted on the upper surface of the base through a vertical rod, a central groove is provided on the detection table, a first bracket and a second bracket are fixedly mounted on the base, a lateral drive module is mounted on the first bracket, a power source of the lateral drive module is a positioning motor, and a total drive module is mounted on the second bracket; An adsorption mechanism, wherein the adsorption mechanism is installed on the main driving module, and the adsorption mechanism is driven by the main driving module, and the silicon wafer to be inspected is positioned by the adsorption mechanism; A light source board, a camera positioning bracket is fixedly mounted on the movable seat of the lateral driving module, the light source board is fixed on the side wall at the lower side of the camera positioning bracket, and the light source board is connected to the light source controller on the base by electrical signals; The edge-finding positioning camera is fixedly mounted on the upper side of the camera positioning bracket, and the edge-finding positioning camera is arranged corresponding to the light source board, and a protective shell is installed on the outer side of the edge-finding positioning camera.

[0005] Preferably, the total driving module is composed of an X-axis driving module and a Y-axis driving module, the X-axis driving module is fixed on the second bracket, the Y-axis driving module is fixed on the moving seat of the X-axis driving module, the adsorption mechanism is fixed on the moving seat of the Y-axis driving module, and the X-axis driving module and the Y-axis driving module respectively use an X-axis stepper motor and a Y-axis stepper motor as power sources, and the X-axis stepper motor and the Y-axis stepper motor are both connected to the stepper driver on the base for electrical signal connection.

[0006] Preferably, the adsorption mechanism includes a mounting seat, a positioning cover, a rotating member and an adsorption head, the mounting seat is fixed on the moving seat of the Y-axis drive module, the rotating member is rotatably mounted on the positioning cover via a ball bearing, the positioning cover is fixedly mounted on the mounting seat, the adsorption head is fixedly mounted on the rotating member, a steering stepper motor is fixedly mounted on the mounting seat, the steering stepper motor is electrically connected to the stepper driver on the base, and a transmission gear is fixedly mounted on the output shaft of the steering stepper motor, a ring gear is integrally formed on the lower end face of the rotating member, and the ring gear is meshed with the transmission gear.

[0007] Preferably, a main air hole is opened through the center position of the rotating part, and a connecting air channel and an annular air channel are opened on the upper end surface of the rotating part, and the annular air channel is connected with the main air hole through the connecting air channel. A central adsorption groove and an edge adsorption groove are opened on the adsorption head, and when the adsorption head is fixedly connected to the rotating part, the edge adsorption groove is connected with the annular air channel. The adsorption head is composed of an adsorption head body and a sealing rubber layer, and the sealing rubber layer is fixedly glued to the upper surface of the adsorption head body.

[0008] Preferably, a transfer tube is integrally formed on the lower end surface of the rotating part at the position of the main air hole, and a transfer seat is fixedly connected to the inner cavity side wall of the positioning cover through a connecting rod, and a sealed bearing is fixedly connected to the port side wall of the transfer seat. When the rotating part is actually installed, the transfer tube is inserted into the inner hole of the sealing bearing, and a connecting air pipe is integrally formed on the lower end surface of the transfer seat. An air pump is fixedly installed on the mounting seat, and the connecting air pipe is connected to the air inlet port of the air pump.

[0009] Preferably, a sealing groove is provided on the outer wall of the adapter tube, and a rubber sealing ring is embedded in the sealing groove. When the adapter tube is actually docked with the sealing bearing, the rubber sealing ring is in a compressed state. A threaded hole is provided on the upper end surface of the rotating part, and a countersunk bolt hole is provided on the adsorption head. The adsorption head is fixedly mounted on the rotating part by a positioning bolt.

[0010] Preferably, a snap-fit ​​groove is provided on the side wall of the nut of the positioning bolt, and an airbag groove is provided on the side wall of the central adsorption groove, the bottom of the airbag groove is connected with the countersunk bolt hole through a connecting hole and an air hole, the cross-section of the connecting hole is a regular hexagon, a limiting plate is fixedly connected at the port position of the airbag groove, and primary mesh holes are evenly provided on the limiting plate, a guide rod is movably provided in the connecting hole, the cross-sectional size of the guide rod matches the connecting hole, and a movable plate is integrally formed with the inner end of the guide rod, the movable plate is movably provided in the airbag groove, and a secondary mesh hole is provided on the movable plate, an inflatable airbag is provided in the airbag groove, gas is injected into the inflatable airbag, a return spring is sleeved on the guide rod, and a snap-fit ​​protrusion is integrally formed on the outer end face of the guide rod.

[0011] Preferably, the cross-section of the engaging groove is U-shaped, and the engaging groove is arranged in a circle at equal intervals around the nut of the positioning bolt, and the size of the engaging protrusion matches the engaging groove. After the vacuum pump completes the vacuuming, the expansion airbag expands and pushes the movable plate to allow the engaging protrusion to be embedded in the engaging groove. After the central adsorption groove and the edge adsorption groove are depressurized, the expansion airbag shrinks, and the movable plate is pushed to its original position by the return spring, and at this time, the engaging protrusion is completely detached from the engaging groove.

[0012] Preferably, the expansion airbag is elliptical in shape, and an octagonal support frame is fixedly glued to both ends of the expansion airbag, the claw body of the octagonal support frame is arc-shaped, and the central adsorption groove and the countersunk bolt hole are connected through a connecting air hole.

[0013] A method for visual inspection and compensation to achieve micron-level repeatability positioning, the method for visual inspection and compensation to achieve micron-level repeatability positioning is implemented by the above-mentioned visual inspection and compensation to achieve micron-level repeatability positioning device, the method comprising: The adaptive wafer size motor moves to the corresponding image acquisition point according to the different sizes of the silicon wafer 13; After the silicon wafer 13 is sent to the rotation center, the negative pressure is turned on to adsorb the silicon wafer 13 onto the adsorption mechanism 2, and the centrifugal force during rotation is offset by increasing the positive pressure; The light source board 3 performs imaging in a back-lighting manner, and the light source controller 20 adjusts the brightness to adapt to the edge imaging effect of the blue film of different thicknesses on the silicon wafer 13; The steering stepper motor 26 starts to rotate, and during the rotation, the controller triggers the edge positioning camera 4 to capture images through a fixed number of pulses for image collection; If OCR is required, the positioning motor 53 will move to the OCR position under the edge-finding positioning camera 4 according to the visual calculation results to perform OCR recognition; After OCR recognition is completed, the main drive module will move to the final set positioning angle and the XY position after eccentricity compensation at that angle; The silicon wafer 13 rotates 372°, and the camera takes pictures in a flying manner, collecting an image every 3°, and discarding the images of rotation acceleration and deceleration, and selecting the images collected at a uniform speed; Extract the edge points of each image, and identify and mark the gap area Id and the matching position of the gap feature image; The image coordinates of each image edge point are converted into a world coordinate system with the rotation center as the coordinate origin according to the shooting angle; Eliminate the edge points of the gap area, and fill in the points by rotating the edge points close to the gap area 3° around the rotation center using the rotation matrix; Perform circle fitting through edge points to find the actual center coordinates of the circle in the world coordinate system; According to the movement from point N to point M, the actual world coordinates of the gap are calculated through the offset from the gap feature image matching position to the image center and the world coordinates of the gap under the ideal circle. According to the movement from point M to point L, the actual gap world coordinates rotate around the image center of the ideal circle gap world coordinates, and the complementary angle of the gap area is rotated to obtain the world coordinates of the gap tilt angle; The world coordinate position of the actual circle center is connected with the world coordinate of the inclination angle of the gap in the M to L region, and the rotation angle P1 of the actual circle center around the rotation center is calculated; The actual world coordinates of the center of the circle are obtained by rotating the angle P1 around the rotation center through the rotation matrix to obtain the world coordinates of the actual center of the circle after rotation (X L ,Y L ), this XY is the compensation value for the actual center of the circle to move to the rotation center; Rotate the angle P2, where P2=P1+12°, and then translate the XY compensation. The first positioning is completed, and the secondary gap feature matching begins to obtain the gap feature image matching position. The angle Q from the gap feature image matching position to the rotation center and the Y axis is the secondary compensation angle data. The pixel offset in the row direction from the gap feature image to the image center * pixel equivalent is the secondary Y compensation: Y L0 ; Move to the position after the secondary compensation positioning, the secondary positioning is completed, and the third gap feature matching is started to obtain the XY pixel offset from the gap feature image matching position to the image center. Through the pixel equivalent, the world coordinate system offset is calculated: X L1 ,Y L1 ; According to the set positioning angle D, the first positioning rotation angle P1 and the secondary compensation angle Q, the total rotation angle R1 is obtained, where R1=-(P1+Q)+D. The actual world coordinate of the center of the circle rotates around the rotation center by an angle R1, and the actual world coordinate of the center of the circle after rotation (X M ,Y M ); (X M ,Y M )+Y L0 The trigonometric components of the positioning angle + (X L1 With Y L1 ) in the trigonometric components of the positioning angle, and the final compensation (X N ,Y N ); After the secondary positioning movement is completed, the rotation axis moves relative to the angle D, where D is the positioning angle, and the XY axis moves absolutely to X. N ,Y N , the final positioning can be completed.

[0014] Compared with the prior art, the present invention has the following beneficial effects: By setting up a visual inspection and compensation device composed of a base, adsorption mechanism, light source board and edge-finding positioning camera, we can achieve micron-level repeatability positioning. By using a 2-megapixel camera to replace the high-precision laser sensor, we can solve the problem of compatible detection of transparent and opaque objects to be tested, increase the detection range to 22mm, reduce costs and achieve micron-level repeatability. Stepper motors are used to replace high-cost DD motors, and visual algorithms are used to compensate for the concentricity deviation of the stepper motor's rotor axis rotation and the backlash problem in forward and reverse rotation, achieving micron-level repeatability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a schematic diagram of the internal structure of the present invention; Figure 3 This is a schematic diagram of the distribution of the light source board and the edge-finding positioning camera of the present invention; Figure 4 It is a schematic diagram of the adsorption mechanism of the present invention; Figure 5 A half-section view of the adsorption mechanism of the present invention; Figure 6 for Figure 5 A schematic diagram of the structure enlargement in the middle; Figure 7 for Figure 5 A magnified schematic diagram of the structure at B in the middle; Figure 8 for Figure 7 A magnified schematic diagram of the structure at C in the middle; Fig. 9 for Figure 7 A magnified schematic diagram of the structure at D in the middle; Fig.10 It is an upper side view of the rotating member of the present invention; Fig.11 It is a lower side view of the rotating member of the present invention; Fig.12 It is a schematic diagram of the structure of the adsorption head of the present invention; Fig.13 It is a schematic diagram of the engaging protrusion structure of the present invention; Fig.14 This is a schematic diagram of the positioning bolt structure of the present invention; Fig.15 This is a schematic diagram of the connection between the expansion airbag and the octopus support frame of the present invention; Fig.16 This is a schematic diagram of the precision positioning method of the present invention.

[0016] In the figure: base 1, adsorption mechanism 2, light source board 3, edge-finding positioning camera 4, vertical pole 5, detection table 6, first bracket 7, second bracket 8, lateral drive module 9, center groove 10, camera positioning bracket 11, protective shell 12, silicon chip 13, X-axis drive module 14, Y-axis drive module 15, mounting seat 16, positioning cover 17, rotating part 18, adsorption head 19, light source controller 20, main air hole 21, connecting airway 22, annular airway 23, transfer tube 24, annular gear 25, steering stepping motor 26, transmission gear 27, connecting Connecting rod 28, adapter seat 29, sealed bearing 30, connecting air pipe 31, rubber sealing ring 32, stepping driver 33, threaded hole 34, central adsorption groove 35, edge adsorption groove 36, countersunk bolt hole 37, adsorption head body 38, sealing rubber layer 39, positioning bolt 40, air bag groove 41, connecting hole 42, air hole 43, limit plate 44, guide rod 45, movable plate 46, expansion air bag 47, return spring 48, engaging protrusion 49, engaging groove 50, octopus support frame 51, connecting air hole 52, positioning motor 53, ball bearing 55. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] See also Figure 1-16 The present invention provides the following three preferred embodiments: Embodiment 1: A device for visual inspection and compensation that achieves micron-level repeatability positioning includes a base 1, an adsorption mechanism 2, a light source board 3 and an edge-finding positioning camera 4. A detection table 6 is fixedly installed on the upper surface of the base 1 through a vertical rod 5. A center groove 10 is provided on the detection table 6. A first bracket 7 and a second bracket 8 are fixedly installed on the base 1. A lateral drive module 9 is installed on the first bracket 7. The power source of the lateral drive module 9 is a positioning motor 53. A main drive module is installed on the second bracket 8. The adsorption mechanism 2 is installed on the main drive module, and the adsorption mechanism 2 is driven by the main drive module, and a silicon wafer 13 to be inspected is positioned by the adsorption mechanism 2. A camera positioning bracket 11 is fixedly installed on the movable seat of the lateral drive module 9. The light source board 3 is fixed on the side wall at the lower side of the camera positioning bracket 11, and the light source board 3 and the light source on the base 1 are connected. The source controller 20 is connected with an electrical signal, the edge-finding positioning camera 4 is fixedly mounted on the upper side of the camera positioning bracket 11, and the edge-finding positioning camera 4 is arranged corresponding to the light source board 3. The outer side of the edge-finding positioning camera 4 is installed with a protective shell 12. The edge-finding positioning camera 4 is a 2-megapixel camera, and a device for visual detection and compensation composed of a base 1, an adsorption mechanism 2, a light source board 3 and an edge-finding positioning camera 4 is set to achieve micron-level repeatability positioning. By using a 2-megapixel camera to replace the high-precision laser sensor, the problem of compatible detection of transparent and opaque objects to be tested is solved, the detection range is increased to 22mm, the cost is reduced and the repeatability accuracy of the micron level is achieved. A stepper motor is used to replace the high-cost DD motor, and a visual algorithm is used to compensate for the concentricity deviation of the stepper motor shaft rotation and the forward and reverse backlash problems to achieve micron-level repeatability accuracy.

[0019] The total driving module is composed of an X-axis driving module 14 and a Y-axis driving module 15. The X-axis driving module 14 is fixed on the second bracket 8, the Y-axis driving module 15 is fixed on the moving seat of the X-axis driving module 14, the adsorption mechanism 2 is fixed on the moving seat of the Y-axis driving module 15, and the X-axis driving module 14 and the Y-axis driving module 15 respectively use the X-axis stepping motor and the Y-axis stepping motor as power sources, and the X-axis stepping motor and the Y-axis stepping motor are both connected to the stepping driver 33 on the base 1 for electrical signal connection.

[0020] The adsorption mechanism 2 includes a mounting seat 16, a positioning cover 17, a rotating member 18 and an adsorption head 19. The mounting seat 16 is fixed on the moving seat of the Y-axis driving module 15. The rotating member 18 is rotatably mounted on the positioning cover 17 through a ball bearing 55. The positioning cover 17 is fixedly mounted on the mounting seat 16. The adsorption head 19 is fixedly mounted on the rotating member 18. A steering stepper motor 26 is fixedly mounted on the mounting seat 16. The steering stepper motor 26 is electrically connected to the stepper driver 33 on the base 1, and a transmission gear 27 is fixedly mounted on the output shaft of the steering stepper motor 26. The lower end surface of the rotating member 18 is integrally formed with a ring gear. The wheel 25, the ring gear 25 and the transmission gear 27 are meshed with each other. A main air hole 21 is opened through the center position of the rotating part 18, and a connecting air channel 22 and an annular air channel 23 are opened on the upper end surface of the rotating part 18. The annular air channel 23 is connected with the main air hole 21 through the connecting air channel 22. A central adsorption groove 35 and an edge adsorption groove 36 are opened on the adsorption head 19. When the adsorption head 19 is fixedly connected to the rotating part 18, the edge adsorption groove 36 is connected with the annular air channel 23. The adsorption head 19 is composed of an adsorption head body 38 and a sealing rubber layer 39. The sealing rubber layer 39 is fixedly glued to the upper surface of the adsorption head body 38.

[0021] The lower end surface of the rotating member 18 is integrally formed with an adapter tube 24 at the position of the main air hole 21, and an adapter seat 29 is fixedly connected to the inner cavity side wall of the positioning cover 17 through a connecting rod 28. A sealing bearing 30 is fixedly connected to the port side wall position of the adapter seat 29. When the rotating member 18 is actually installed, the adapter tube 24 is inserted into the inner hole of the sealing bearing 30, and the lower end surface of the adapter seat 29 is integrally formed with a connecting air pipe 31. An air pump is fixedly installed on the mounting seat 16, and the connecting air pipe 31 is connected to the air inlet port of the air pump. The adapter tube 24 is connected to each other, and a sealing groove is provided on the outer wall of the adapter tube 24, in which a rubber sealing ring 32 is embedded and installed. When the adapter tube 24 is actually connected to the sealing bearing 30, the rubber sealing ring 32 is in a compressed state. A threaded hole 34 is provided on the upper end surface of the rotating part 18, and a countersunk bolt hole 37 is provided on the adsorption head 19. The adsorption head 19 is fixedly installed on the rotating part 18 by a positioning bolt 40. The rubber sealing ring 32 is provided to improve the sealing performance of the connection position between the adapter tube 24 and the sealing bearing 30.

[0022] Embodiment 2: On the basis of embodiment 1, a snap-fit ​​groove 50 is provided on the side wall of the nut of the positioning bolt 40, an airbag groove 41 is provided on the side wall of the central adsorption groove 35, the bottom of the airbag groove 41 is connected with the countersunk bolt hole 37 through a connecting hole 42 and an air hole 43, the cross-section of the connecting hole 42 is a regular hexagon, a limiting plate 44 is fixedly connected at the port position of the airbag groove 41, a primary mesh is evenly provided on the limiting plate 44, a guide rod 45 is movably provided in the connecting hole 42, the cross-sectional size of the guide rod 45 matches the connecting hole 42, and a movable plate 46 is integrally formed on the inner side end of the guide rod 45, the movable plate 46 is movably provided in the airbag groove 41, and a secondary mesh is provided on the movable plate 46, an inflatable airbag 47 is provided in the airbag groove 41, gas is injected into the inflatable airbag 47, a return spring 48 is sleeved on the guide rod 45, and a snap-fit ​​protrusion 49 is integrally formed on the outer end surface of the guide rod 45.

[0023] The cross section of the engaging groove 50 is U-shaped, and the engaging groove 50 is arranged around the nut of the positioning bolt 40 at equal intervals. The size of the engaging protrusion 49 matches the engaging groove 50. After the vacuum pump is completed, since the total amount of gas inside the expanded airbag 47 is a fixed value, in order to achieve the adsorption of the silicon wafer 13 by the adsorption head 19, the air pressure inside the central adsorption groove 35, the edge adsorption groove 36, and the airbag groove 41 will be reduced through the vacuum pump, and the air pressure inside the expanded airbag 47 will be greater than the air pressure inside the airbag groove 41. 1, so the inflatable airbag 47 is inflated and pushes the movable plate 46 to allow the engaging protrusion 49 to be embedded in the engaging groove 50. After the central adsorption groove 35 and the edge adsorption groove 36 are depressurized, the air pressure in the central adsorption groove 35, the edge adsorption groove 36 and the airbag groove 41 is restored to the standard atmospheric pressure, and the internal air pressure value of the inflatable airbag 47 after expansion is less than the external standard atmospheric pressure, so the inflatable airbag 47 is compressed, so that the inflatable airbag 47 shrinks to its original size, so that the movable plate 46 The thrust of the expansion airbag 47 is lost, and the movable plate 46 is pushed to the original position by the return spring 48, and at this time, the engaging protrusion 49 is completely separated from the engaging groove 50. By setting the limit plate 44, the guide rod 45, the movable plate 46, the expansion airbag 47, the return spring 48, the engaging protrusion 49, and opening the engaging groove 50 on the nut side wall of the positioning bolt 40, the pressure in the airbag groove 41 is reduced through the negative pressure suction process, so that the expansion airbag 47 is expanded, thereby pushing the engaging protrusion 49 into the engaging groove 50. In the process, a self-locking effect is formed on the positioning bolt 40, thereby preventing the positioning bolt 40 from loosening due to the operation of the equipment, which causes the sealing between the structures to decrease, thereby affecting the stability of the adsorption positioning. The power source of the structure is the force generated by the expansion and contraction of the expansion bag 47, and the expansion and contraction of the expansion bag 47 is caused by the operation of the vacuum pump during the adsorption positioning of the silicon wafer 13. Therefore, the structure does not require any other additional power source, thereby effectively optimizing the power control system of the device.

[0024] The expansion airbag 47 is elliptical in shape, and an octagonal support frame 51 is fixedly glued at both ends of the expansion airbag 47. The claws of the octagonal support frame 51 are arc-shaped, and the central adsorption groove 35 and the countersunk bolt hole 37 are connected through a connecting air hole 52. The octagonal support frame 51 can prevent the expansion of the expansion airbag 47 from clogging the mesh.

[0025] Embodiment 3: Based on Embodiment 2, a method for visual inspection and compensation to achieve micron-level repeatability positioning is provided. The method for visual inspection and compensation to achieve micron-level repeatability positioning is implemented by the above-mentioned visual inspection and compensation to achieve micron-level repeatability positioning device. The method comprises: The adaptive wafer size motor moves to the corresponding image acquisition point according to different silicon wafer 13 sizes (12inch / 8inch); After the silicon wafer 13 is sent to the rotation center, the negative pressure is turned on to adsorb the silicon wafer 13 onto the adsorption mechanism 2, and the centrifugal force during rotation is offset by increasing the positive pressure; The light source board 3 performs imaging in a back-lighting manner, and the light source controller 20 adjusts the brightness to adapt to the edge imaging effect of the blue film of different thicknesses on the silicon wafer 13; The steering stepper motor 26 starts to rotate, and during the rotation, the controller triggers the edge positioning camera 4 to capture images through a fixed number of pulses for image collection; If OCR is required, the positioning motor 53 will move to the OCR position under the edge-finding positioning camera 4 according to the visual calculation results to perform OCR recognition; After OCR recognition is completed, the main drive module will move to the final set positioning angle and the XY position after eccentricity compensation at that angle; The silicon wafer 13 rotates 372°, and the camera takes pictures in a flying manner, collecting an image every 3°, and discarding the images of rotation acceleration and deceleration, and selecting the images collected at a uniform speed; Extract the edge points of each image, and identify and mark the gap area Id and the matching position of the gap feature image; The image coordinates of each image edge point are converted into a world coordinate system with the rotation center as the coordinate origin according to the shooting angle; Eliminate the edge points of the gap area, and fill in the points by rotating the edge points close to the gap area 3° around the rotation center using the rotation matrix; Perform circle fitting through edge points to find the actual center coordinates of the circle in the world coordinate system; like Fig.16 As shown (N->M): the actual world coordinates of the gap are calculated by the offset from the gap feature image matching position to the image center and the world coordinates of the gap under the ideal circle (the center of the silicon wafer 13 is consistent with the rotation center). like Fig.16 As shown (M->L): the actual gap world coordinates are rotated around the ideal circle gap world coordinates (the image center of the actual gap area image) by the complementary angle of (gap area Id * 3°) to obtain (the world coordinates of the gap tilt angle of the L area in the M area); The actual circle center world coordinate position is connected with (the world coordinate of the inclination angle of the notch in the L region of the M region) to calculate the rotation angle P1 of the actual circle center around the rotation center; The actual world coordinates of the center of the circle are obtained by rotating the angle P1 around the rotation center through the rotation matrix to obtain the world coordinates of the actual center of the circle after rotation (X L ,Y L ), this XY is the compensation value for the actual center of the circle to move to the rotation center; Rotate the angle P2, where P2=P1+12°, and then translate the XY compensation. The first positioning is completed, and the secondary gap feature matching begins to obtain the gap feature image matching position. The angle Q from the gap feature image matching position to the rotation center and the Y axis is the secondary compensation angle data. The pixel offset in the row direction from the gap feature image to the image center * pixel equivalent is the secondary Y compensation: Y L0 ; Move to the position after the secondary compensation positioning, the secondary positioning is completed, and the third gap feature matching is started to obtain the XY pixel offset from the gap feature image matching position to the image center. Through the pixel equivalent, the world coordinate system offset is calculated: X L1 ,Y L1 ; According to the set positioning angle D, the first positioning rotation angle (angle P1) and the secondary compensation angle (angle Q), the total rotation angle R1 is obtained, where R1=-(P1+Q)+D. This formula can be understood as P1 and Q are the angle values ​​of the reverse rotation back to the bottom of the camera (i.e. 0°). The final setting angle D is a positive rotation, so the first rotation to the bottom of the camera is -(P1+Q). The total rotation angle R1 after rotating to the final setting angle D is -(P1+Q)+D, and the total rotation angle R1 is obtained. The actual center of the world coordinate rotates around the rotation center by an angle R1, and the actual center of the world coordinate after rotation (X M ,Y M ); (X M ,Y M )+Y L0 The trigonometric components of the positioning angle + (X L1 With Y L1 ) in the trigonometric components of the positioning angle, and the final compensation (X N ,Y N ); After the secondary positioning movement is completed, the rotation axis moves relative to angle D, and the XY axis moves absolutely to angle X. N ,Y N , the final positioning can be completed.

[0026] Although the above describes the illustrative specific implementation methods of the present application so that technicians in this technical field can understand the present application, the present application is not limited to the scope of the specific implementation methods. For ordinary technicians in this technical field, as long as various changes are within the spirit and scope of the present application defined and determined by the attached claims, all application creations using the concept of the present application are protected.

Claims

1. Equipment for visual inspection and compensation with micron-level repeatability, characterized by: include: A base (1), wherein a detection table (6) is fixedly mounted on the upper surface of the base (1) via a vertical rod (5), wherein a central groove (10) is provided on the detection table (6), wherein a first bracket (7) and a second bracket (8) are fixedly mounted on the base (1), wherein a lateral drive module (9) is mounted on the first bracket (7), wherein a power source of the lateral drive module (9) is a positioning motor (53), and wherein a total drive module is mounted on the second bracket (8); An adsorption mechanism (2), wherein the adsorption mechanism (2) is mounted on a main drive module, the adsorption mechanism (2) is driven by the main drive module, and the silicon wafer (13) to be inspected is positioned by the adsorption mechanism (2); A light source board (3), a camera positioning bracket (11) is fixedly mounted on the movable seat of the lateral driving module (9), the light source board (3) is fixed on the side wall of the camera positioning bracket (11) at a lower position, and the light source board (3) is electrically connected to a light source controller (20) on the base (1); An edge-finding positioning camera (4) is fixedly mounted on the upper side of the camera positioning bracket (11), and the edge-finding positioning camera (4) is arranged corresponding to the light source board (3), and a protective housing (12) is installed on the outer side of the edge-finding positioning camera (4).

2. The device for visual inspection and compensation with micron-level repeatability positioning according to claim 1, characterized in that: The total drive module is composed of an X-axis drive module (14) and a Y-axis drive module (15), wherein the X-axis drive module (14) is fixed on a second bracket (8), the Y-axis drive module (15) is fixed on a movable seat of the X-axis drive module (14), the adsorption mechanism (2) is fixed on the movable seat of the Y-axis drive module (15), and the X-axis drive module (14) and the Y-axis drive module (15) respectively use an X-axis stepping motor and a Y-axis stepping motor as power sources, and the X-axis stepping motor and the Y-axis stepping motor are both electrically connected to a stepping driver (33) on the base (1).

3. The device for visual inspection and compensation with micron-level repeatability positioning according to claim 2, characterized in that: The adsorption mechanism (2) comprises a mounting seat (16), a positioning cover (17), a rotating member (18) and an adsorption head (19); the mounting seat (16) is fixed on a moving seat of a Y-axis driving module (15); the rotating member (18) is rotatably mounted on the positioning cover (17) via a ball bearing (55); the positioning cover (17) is fixedly mounted on the mounting seat (16); the adsorption head (19) is fixedly mounted on the rotating member (18); a steering stepping motor (26) is fixedly mounted on the mounting seat (16); the steering stepping motor (26) is electrically connected to a stepping driver (33) on the base (1); a transmission gear (27) is fixedly mounted on the output shaft of the steering stepping motor (26); a ring gear (25) is integrally formed on the lower end surface of the rotating member (18); the ring gear (25) is meshed with the transmission gear (27).

4. The device for visual inspection and compensation with micron-level repeatability positioning according to claim 3, characterized in that: A main air hole (21) is provided through the center of the rotating member (18), and a connecting air channel (22) and an annular air channel (23) are provided on the upper end surface of the rotating member (18); the annular air channel (23) is connected to the main air hole (21) via the connecting air channel (22); a central adsorption groove (35) and an edge adsorption groove (36) are provided on the adsorption head (19); when the adsorption head (19) is fixedly connected to the rotating member (18), the edge adsorption groove (36) is connected to the annular air channel (23); the adsorption head (19) is composed of an adsorption head body (38) and a sealing rubber layer (39); the sealing rubber layer (39) is fixedly bonded to the upper surface of the adsorption head body (38).

5. The device for visual inspection and compensation with micron-level repeatability positioning according to claim 4, characterized in that: The lower end surface of the rotating member (18) is integrally formed with a transfer tube (24) at the position of the main air hole (21); a transfer seat (29) is fixedly connected to the inner cavity side wall of the positioning cover (17) via a connecting rod (28); a sealing bearing (30) is fixedly connected to the port side wall of the transfer seat (29); when the rotating member (18) is actually installed, the transfer tube (24) is inserted into the inner hole of the sealing bearing (30); the lower end surface of the transfer seat (29) is integrally formed with a connecting air pipe (31); an air pump is fixedly mounted on the mounting seat (16); and the connecting air pipe (31) is connected to the air inlet port of the air pump.

6. The device for visual inspection and compensation with micron-level repeatability positioning according to claim 5, characterized in that: A sealing groove is provided on the outer wall of the transfer tube (24), a rubber sealing ring (32) is embedded in the sealing groove, and when the transfer tube (24) is actually connected to the sealing bearing (30), the rubber sealing ring (32) is in a compressed state. A threaded hole (34) is provided on the upper end surface of the rotating member (18), a countersunk bolt hole (37) is provided on the adsorption head (19), and the adsorption head (19) is fixedly mounted on the rotating member (18) by means of a positioning bolt (40).

7. The device for visual inspection and compensation with micron-level repeatability positioning according to claim 6, characterized in that: The nut side wall of the positioning bolt (40) is provided with a snap-fitting groove (50), the side wall of the central adsorption groove (35) is provided with an airbag groove (41), the groove bottom of the airbag groove (41) is connected with the countersunk bolt hole (37) through a connecting hole (42) and an air hole (43), the cross section of the connecting hole (42) is a regular hexagon, the end position of the airbag groove (41) is fixedly connected with a limiting plate (44), the limiting plate (44) is evenly provided with primary mesh holes, and a guide rod (41) is movably provided in the connecting hole (42). 5), the cross-sectional dimensions of the guide rod (45) match the connecting hole (42), and the inner end of the guide rod (45) is integrally formed with a movable plate (46), the movable plate (46) is movably arranged in the airbag groove (41), and a secondary mesh is opened on the movable plate (46), an expansion airbag (47) is arranged in the airbag groove (41), and gas is injected into the expansion airbag (47), a return spring (48) is sleeved on the guide rod (45), and a locking protrusion (49) is integrally formed on the outer end surface of the guide rod (45).

8. The device for visual inspection and compensation with micron-level repeatability positioning according to claim 7, characterized in that: The cross-section of the engaging groove (50) is U-shaped, and the engaging groove (50) is arranged in a circle at equal intervals around the nut of the positioning bolt (40). The size of the engaging protrusion (49) matches the engaging groove (50). After the vacuum pump completes the vacuuming, the expansion airbag (47) expands and pushes the movable plate (46) to allow the engaging protrusion (49) to be embedded in the engaging groove (50). After the central adsorption groove (35) and the edge adsorption groove (36) are depressurized, the expansion airbag (47) contracts, and the movable plate (46) is pushed to its original position by the return spring (48). At this time, the engaging protrusion (49) is completely detached from the engaging groove (50).

9. The device for visual inspection and compensation with micron-level repeatability positioning according to claim 8, characterized in that: The expansion airbag (47) is arranged in an elliptical shape, and an octagonal support frame (51) is fixedly glued to both ends of the expansion airbag (47), the claw body of the octagonal support frame (51) is arranged in an arc shape, and the central adsorption groove (35) and the countersunk bolt hole (37) are connected through a connecting air hole (52).

10. A method for visual inspection and compensation to achieve micron-level repeatability positioning, characterized in that: The method for visual inspection and compensation to achieve micron-level repeatability positioning is implemented by the device for visual inspection and compensation to achieve micron-level repeatability positioning according to any one of claims 1 to 9, and the method comprises: The adaptive wafer size motor moves to the corresponding image acquisition point according to the size of the silicon wafer (13); After the silicon wafer (13) is sent to the rotation center, the negative pressure is turned on to adsorb the silicon wafer (13) onto the adsorption mechanism (2), thereby increasing the positive pressure to offset the centrifugal force during rotation; The light source plate (3) performs imaging in a back-lighting manner, and the light source controller (20) adjusts the brightness to adapt to the edge imaging effect of the blue film of different thicknesses on the silicon wafer (13); The steering stepper motor (26) starts to rotate, and during the rotation, the controller triggers the edge positioning camera (4) to capture images through a fixed number of pulses for image collection; If OCR is required, the positioning motor (53) will move to the OCR position under the edge-finding positioning camera (4) according to the visual calculation result to perform OCR recognition; After OCR recognition is completed, the main drive module will move to the final set positioning angle and the XY position after eccentricity compensation at that angle; The silicon wafer (13) is rotated 372°, and the camera is used to take pictures, collecting an image every 3°, and discarding images that are accelerated or decelerated during rotation, and selecting images that are collected at a constant speed; Extract the edge points of each image, and identify and mark the gap area Id and the matching position of the gap feature image; The image coordinates of each image edge point are converted into a world coordinate system with the rotation center as the coordinate origin according to the shooting angle; Eliminate the edge points of the gap area, and fill in the points by rotating the edge points close to the gap area by 3° around the rotation center through the rotation matrix; Perform circle fitting through edge points to find the actual center coordinates of the circle in the world coordinate system; According to the movement from point N to point M, the actual world coordinates of the gap are calculated through the offset from the gap feature image matching position to the image center and the world coordinates of the gap under the ideal circle. According to the movement from point M to point L, the actual gap world coordinates rotate around the image center of the ideal circle gap world coordinates, and the complementary angle of the gap area is rotated to obtain the world coordinates of the gap tilt angle; The world coordinate position of the actual circle center is connected with the world coordinate of the inclination angle of the gap in the M to L region, and the rotation angle P1 of the actual circle center around the rotation center is calculated; The actual world coordinates of the center of the circle are obtained by rotating the angle P1 around the rotation center through the rotation matrix to obtain the world coordinates of the actual center of the circle after rotation (X L ,Y L )This XY is the compensation value for the actual center of the circle to move to the rotation center; Rotate the angle P2, where P2=P1+12°, and then translate the XY compensation. The first positioning is completed, and the secondary gap feature matching begins to obtain the gap feature image matching position. The angle Q from the gap feature image matching position to the rotation center and the Y axis is the secondary compensation angle data. The pixel offset in the row direction from the gap feature image to the image center * pixel equivalent is the secondary Y compensation: Y L0 ; Move to the position after the secondary compensation positioning, the secondary positioning is completed, and the third gap feature matching is started to obtain the XY pixel offset from the gap feature image matching position to the image center. Through the pixel equivalent, the world coordinate system offset is calculated: X L1 ,Y L1 ; According to the set positioning angle D + the first positioning rotation angle P1 + the secondary compensation angle Q, the total rotation angle R1 is obtained, where R1=-(P1+Q)+D. The actual world coordinate of the center of the circle rotates around the rotation center by an angle R1, and the actual world coordinate of the center of the circle after rotation (X M ,Y M ); (X M ,Y M )+Y L0 The trigonometric components of the positioning angle + (X L1 With Y L1 ) in the trigonometric components of the positioning angle, and the final compensation (X N ,Y N ); After the secondary positioning movement is completed, the rotation axis moves relative to angle D, and the XY axis moves absolutely to angle X. N ,Y N , the final positioning can be completed.

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