Wafer alignment mechanism and wafer alignment method

Abstract

The invention relates to the technical field of semiconductors, and discloses a wafer alignment mechanism and a wafer alignment method. The wafer alignment mechanism comprises a bearing device, a positioning device, a displacement sensor and a linear driving module, the bearing device comprises a bottom plate and two first positioning blocks, and the two first positioning blocks are installed on the bottom plate; the positioning device comprises a driving assembly and a second positioning block, the driving assembly is installed on the bottom plate, the driving assembly is in driving connection with the second positioning block, the two first positioning blocks are symmetrically arranged on the two sides of the moving direction of the second positioning block, a bearing station is formed between the second positioning block and the two first positioning blocks, and the bearing station is used for bearing a to-be-detected piece; the driving assembly is used for driving the second positioning block to move in the first direction, and the second positioning block and the two first positioning blocks clamp or loosen a to-be-detected piece; the displacement sensor is installed on the bottom plate, and when the second positioning block abuts against the to-be-detected piece, the second positioning block can abut against the detection end of the displacement sensor. The linear driving module is in driving connection with the bottom plate.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a wafer alignment mechanism and a wafer alignment method. Background Art

[0002] At present, when devices such as coating and developing machines, photolithography machines, and wet process equipment are in working state, there are strict requirements on the centering position of the wafer. The center of the wafer and the preset alignment center in the device must be within a certain error range. In patent CN101494188A, the wafer is aligned by tightening and limiting on both sides. However, when the wafer has size deviation, the diameter and center position of the wafer cannot be detected, and the centering accuracy is poor.

[0003] Based on this, a wafer alignment mechanism and a wafer alignment method are urgently needed to solve the above-mentioned problems. Summary of the invention

[0004] Based on the above, the purpose of the present invention is to provide a wafer alignment mechanism and a wafer alignment method, which can realize the fixation and measurement of the part to be detected through a driving component. The structure is simpler and data reading is more convenient because there is only one change, which improves the position accuracy of the part to be detected.

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

[0006] In one aspect, a wafer alignment mechanism is provided, comprising:

[0007] A bearing device, comprising a bottom plate and two first positioning blocks, wherein the two first positioning blocks are mounted on the bottom plate;

[0008] A positioning device, comprising a driving assembly and a second positioning block, wherein the driving assembly is mounted on the bottom plate, the driving assembly is drivingly connected to the second positioning block, the two first positioning blocks are symmetrically arranged on both sides of the moving direction of the second positioning block, a bearing station is formed between the second positioning block and the two first positioning blocks, the bearing station is used to bear the to-be-detected part, and the driving assembly is used to drive the second positioning block to move along the first direction so that the second positioning block and the two first positioning blocks clamp or loosen the to-be-detected part;

[0009] A displacement sensor is mounted on the bottom plate, and when the second positioning block is pressed against the to-be-detected member, the second positioning block can contact the detection end of the displacement sensor;

[0010] A linear drive module is drivingly connected to the base plate, and is used to drive the base plate to move along the first direction.

[0011] As an optimal technical solution for a wafer alignment mechanism, the positioning device also includes an abutment, the second positioning block is provided with a first threaded hole extending along the first direction, the abutment is threadedly connected to the first threaded hole, and the end of the abutment can abut against the detection end of the displacement sensor.

[0012] As an optimal technical solution for a wafer alignment mechanism, the driving assembly includes a slide rail, a slider and a driving cylinder, the slide rail is arranged on the base plate, the slider is arranged at the bottom of the second positioning block, the slider is slidably connected to the slide rail, and the driving cylinder is installed on the base plate and drivingly connected to the second positioning block.

[0013] As a preferred technical solution for a wafer alignment mechanism, the driving assembly also includes an elastic member, an adjusting screw and an adjusting nut. The second positioning block is provided with a stepped hole, and the output end of the driving cylinder is provided with a second threaded hole. The adjusting screw is sequentially passed through the small diameter section of the stepped hole, the large diameter section of the stepped hole, and the elastic member and is threadedly connected to the adjusting nut and the second threaded hole. One end of the elastic member abuts against the step surface of the stepped hole, and the other end abuts against the adjusting nut.

[0014] As a preferred technical solution of a wafer alignment mechanism, the two first positioning blocks are provided with a first arcuate surface, the second positioning block is provided with a second arcuate surface, and the second arcuate surface and the two first arcuate surfaces are used to clamp the side wall of the part to be inspected.

[0015] As a preferred technical solution of a wafer alignment mechanism, the angle between the lines connecting the two contact points of the detected object with the smallest diameter and the two first arc-shaped surfaces and the center of the detected object is not less than 104°;

[0016] The angles between the lines connecting the two contact points of the detected part with the largest diameter and the two first arc-shaped surfaces and the center of the detected part are not less than 136°.

[0017] As a preferred technical solution of a wafer alignment mechanism, a plurality of support columns are arranged on the bottom plate, and the support columns are used to support the to-be-detected component.

[0018] On the other hand, a wafer alignment method is provided, using any of the wafer alignment mechanisms described above, the wafer alignment method comprising the following steps:

[0019] S1. Place the part to be tested on the loading station;

[0020] S2, the driving component drives the second positioning block to clamp the to-be-detected component, and the second positioning block contacts the detection end of the displacement sensor, and the displacement sensor obtains the position information of the second positioning block;

[0021] S3, obtaining the diameter of the to-be-detected component and the center offset of the to-be-detected component according to the position information of the second positioning block;

[0022] S4. The carrying device moves along the first direction to compensate for the center offset, so that the center of the to-be-detected component moves to a preset position.

[0023] As a preferred technical solution of a wafer alignment method, in step S3, the diameter of the object to be detected and the center offset of the object to be detected are obtained by comparing the detection information of the displacement sensor with the database; the following steps are used to establish the database:

[0024] S31. Establish a complete digital model in CAD software;

[0025] S32, in the digital model, setting the diameter of the wafer to be tangent to the second positioning block and the two first positioning blocks;

[0026] S33, setting a reference plane, setting the diameter of the wafer to a standard diameter, setting the center offset to 0 mm, and obtaining a size △L1 of the center of the wafer relative to the reference plane, and a size △L2 of the contact point of the displacement sensor relative to the reference plane;

[0027] S34, gradually increasing the setting value of the wafer diameter from low to high, and obtaining the slave values ​​of △L1, △L2 and the center offset, and recording the wafer diameter, △L1, △L2 and the center offset in the database respectively.

[0028] As a preferred technical solution of a wafer alignment method, the wafer alignment method further includes an accuracy verification method, and the accuracy verification method includes the following steps:

[0029] S10, placing a calibration piece of standard diameter between the second positioning block and the two first positioning blocks, and controlling the second positioning block to clamp the calibration piece; adjusting the front and rear positions of the contact surface of the displacement sensor so that the contact surface stays in the middle position of the effective stroke of the displacement sensor, and setting the current position as the "zero position" of the displacement sensor in the system;

[0030] S20, respectively inserting a calibration piece with the largest diameter and a calibration piece with the smallest diameter and clamping them in place, reading the output parameters of the displacement sensor, comparing the output parameters with the database for deviation values, and completing the accuracy verification method if the deviation values ​​are within a preset range.

[0031] The beneficial effects of the present invention are:

[0032] The present invention provides a wafer alignment mechanism and a wafer alignment method. When working, a robot places a piece to be detected on a bearing station; after the placement is completed, a driving component drives the second positioning block to move toward the side of the first positioning block, and pushes the second positioning block to cooperate with the first positioning block to clamp the piece to be detected, thereby fixing the piece to be detected. While the piece to be detected is fixed, the second positioning block abuts against the detection end of the displacement sensor, and the displacement sensor obtains the position information when the second positioning block clamps the piece to be detected; the diameter of the piece to be detected and the center of the circle offset of the piece to be detected are obtained according to the position information of the second positioning block, thereby obtaining the center of the circle position of the piece to be detected, improving the position accuracy of the piece to be detected, improving the subsequent processing accuracy of the piece to be detected, and improving the product quality. Furthermore, when the center of the circle offset of the piece to be detected is obtained through the detection value of the displacement sensor, the linear drive module drives the bottom plate to move along the first direction so that the piece to be detected automatically adjusts its position, and the bearing device moves along the first direction to compensate for the center of the circle offset, so that the center of the circle of the piece to be detected moves to a preset position, so that the robot can transfer the piece to be detected after accurate positioning to other process positions. The present invention adopts a three-point positioning method, two first positioning blocks are fixed, and a second positioning block is movable to achieve fixed clamping of the part to be detected. The part to be detected can be fixed and measured through a driving component. The structure is simpler and data reading is more convenient because there is only one change, which improves the position accuracy of the part to be detected.

[0033] Finally, since the two first positioning blocks are symmetrically arranged on both sides of the moving direction of the second positioning block, the center of the circle of the part to be detected can always be on the center line of the pushing direction of the second positioning block. That is, the symmetrical arrangement of the two first positioning blocks ensures that the center of the circle of the part to be detected can only be offset in the first direction, and will not be offset in the direction perpendicular to the first direction due to the limiting effect on both sides of the two first positioning blocks. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0035] Figure 1 is a structural schematic diagram of a wafer alignment mechanism provided in a specific embodiment of the present invention;

[0036] Figure 2 yes Figure 1 Zoom in on the image at A;

[0037] Figure 3 is a top view of a wafer alignment mechanism provided in a specific embodiment of the present invention;

[0038] Figure 4 yes Figure 3 Sectional view at CC;

[0039] Figure 5 yes Figure 4 Zoom in on the image at B;

[0040] Figure 6 is a flow chart of a wafer alignment method provided by a specific embodiment of the present invention;

[0041] Figure 7 It is a flowchart of establishing a database provided by a specific embodiment of the present invention;

[0042] Figure 8 It is a schematic diagram of a database provided by a specific embodiment of the present invention;

[0043] Fig. 9 It is a flow chart of the accuracy verification method provided by a specific embodiment of the present invention.

[0044] The following are marked in the figure:

[0045] 10. Parts to be tested;

[0046] 1. Carrying device; 11. Bottom plate; 12. First positioning block; 121. First arc-shaped surface; 122. First guiding inclined surface; 13. Support column;

[0047] 2. Positioning device; 21. Driving assembly; 211. Slide rail; 212. Sliding block; 213. Driving cylinder; 214. Elastic member; 215. Adjusting screw; 216. Adjusting nut; 22. Second positioning block; 221. Second arc-shaped surface; 222. Second guiding inclined surface; 23. Rejecting member; 24. Fastening nut;

[0048] 3. Displacement sensor;

[0049] 4. Linear drive module;

[0050] 5. Robotic arm. DETAILED DESCRIPTION

[0051] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0052] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0054] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0055] like Figure 1 and Figure 2 As shown, the present embodiment provides a wafer alignment mechanism, which includes a carrying device 1, a positioning device 2, a displacement sensor 3 and a linear drive module 4. The carrying device 1 includes a base plate 11 and two first positioning blocks 12, and the two first positioning blocks 12 are installed on the base plate 11; the positioning device 2 includes a driving component 21 and a second positioning block 22, and the driving component 21 is installed on the base plate 11, and the driving component 21 is driven and connected to the second positioning block 22. The two first positioning blocks 12 are symmetrically arranged on both sides of the moving direction of the second positioning block 22, and the second positioning block 22 and the two first positioning blocks 12 are arranged in an isosceles triangle. The second positioning block 22 is located at the vertex position of the isosceles triangle, and the two first positioning blocks 12 are respectively located at the two bottom angles of the isosceles triangle. A carrying station is formed between the second positioning block 22 and the two first positioning blocks 12, and the carrying station is used to carry a to-be-detected component 10 (the to-be-detected component 10 in the present embodiment is an 8-inch wafer. In order to facilitate the display of the specific structure of the present wafer alignment mechanism, Figure 1The wafer is set to be transparent, but the actual wafer is not transparent). The driving component 21 is used to drive the second positioning block 22 to move along the first direction, so that the second positioning block 22 and the two first positioning blocks 12 clamp or loosen the part to be detected 10; the displacement sensor 3 is installed on the base plate 11, and when the second positioning block 22 is pressed against the part to be detected 10, the second positioning block 22 can contact the detection end of the displacement sensor 3; the linear drive module 4 is driven and connected to the base plate 11, and the linear drive module 4 is used to drive the base plate 11 to move along the first direction.

[0056] During operation, the robot 5 places the part to be detected 10 on the carrying station. At this time, the part to be detected 10 is located in the area between the two first positioning blocks 12 and the second positioning block 22, and the edge of the part to be detected 10 is close to the first positioning block 12, about 1-3 mm, and the distance from the second positioning block 22 can be appropriately larger, about 3-10 mm, so that the robot 5 can smoothly place the wafer in the area where the carrying station is located; after placement, the drive component 21 drives the second positioning block 22 to move to the side of the first positioning block 12, and pushes the second positioning block 22 to cooperate with the first positioning block 12 to clamp the part to be detected 10, thereby fixing the part to be detected 10. While the part to be detected 10 is fixed, the second positioning block 22 contacts the detection end of the displacement sensor 3, and the displacement sensor 3 obtains the position information of the second positioning block 22 when clamping the part to be detected 10; the diameter of the part to be detected 10 and the center offset of the part to be detected 10 are obtained according to the position information of the second positioning block 22, so that the center position of the part to be detected 10 is obtained, the position accuracy of the part to be detected 10 is improved, the subsequent processing accuracy of the part to be detected 10 is improved, and the product quality is improved. Furthermore, when the center offset of the part to be detected 10 is obtained through the detection value of the displacement sensor 3, the linear drive module 4 drives the bottom plate 11 to move along the first direction so that the part to be detected 10 automatically adjusts its own position, and the carrying device 1 moves along the first direction to compensate for the center offset, so that the center of the part to be detected 10 moves to the preset position, which is convenient for the manipulator 5 to transfer the part to be detected 10 after precise positioning to other process positions. This embodiment adopts a three-point positioning method, with two first positioning blocks 12 fixed and a second positioning block 22 moving to achieve fixed clamping of the part to be detected 10. The part to be detected 10 can be fixed and measured through a driving component 21. The structure is simpler and data reading is more convenient because there is only one change, which improves the position accuracy of the part to be detected 10.

[0057] Furthermore, since the two first positioning blocks 12 are symmetrically arranged on both sides of the moving direction of the second positioning block 22, the center of the circle of the detected member 10 can always be located on the center line of the pushing direction of the second positioning block 22. That is, the symmetrical arrangement of the two first positioning blocks 12 ensures that the center of the circle of the detected member 10 can only be offset in the first direction, and will not be offset in the direction perpendicular to the first direction due to the limiting effect on both sides of the two first positioning blocks 12.

[0058] Preferably, a plurality of support columns 13 are provided on the bottom plate 11, and the support columns 13 are used to support the to-be-detected member 10. In this embodiment, there are four support columns 13, which can support the to-be-detected member 10.

[0059] In this embodiment, the displacement sensor 3 is a contact displacement sensor, and the displacement sensor 3 has a certain telescopic stroke. When the detected component 10 is clamped and positioned, the hard contact surface on the second positioning block 22 pushes the contact displacement sensor probe to retract, and the center offset is measured by the amount of compression of the probe after the resistance. The hard contact surface can ensure sufficient accuracy and service life.

[0060] Preferably, the positioning device 2 further includes a resisting member 23, the second positioning block 22 is provided with a first threaded hole extending along the first direction, the resisting member 23 is threadedly connected to the first threaded hole, the end of the resisting member 23 can abut against the detection end of the displacement sensor 3, the resisting member 23 is used to resist the probe of the displacement sensor 3, and shrink inward by resisting the probe, thereby realizing the displacement detection of the displacement sensor 3. By rotating the resisting member 23, the resisting member 23 can move along the first direction relative to the second positioning block 22, so as to facilitate the adjustment of the position of the crimped displacement sensor 3. Preferably, in this embodiment, the resisting member 23 is a resisting screw, and the positioning device 2 further includes a fastening nut 24, which is threadedly connected to the end of the resisting member 23 away from the displacement sensor 3 to improve the connection strength between the resisting member 23 and the first threaded hole.

[0061] Furthermore, if Figure 1-Figure 5 As shown, the driving assembly 21 includes a slide rail 211, a slider 212 and a driving cylinder 213. The slide rail 211 is arranged on the bottom plate 11, the slider 212 is arranged at the bottom of the second positioning block 22, the slider 212 is slidably connected to the slide rail 211, and the driving cylinder 213 is installed on the bottom plate 11 and is drivingly connected to the second positioning block 22. When the driving cylinder 213 is extended and retracted, it can drive the second positioning block 22 to move along the first direction; furthermore, by arranging the slide rail 211 and the slider 212, the movement stability and movement accuracy of the second positioning block 22 are improved.

[0062] Preferably, the driving assembly 21 further comprises an elastic member 214, an adjusting screw 215 and an adjusting nut 216, the second positioning block 22 is provided with a stepped hole, the output end of the driving cylinder 213 is provided with a second threaded hole, the adjusting screw 215 is sequentially passed through the small diameter section of the stepped hole, the large diameter section of the stepped hole, the elastic member 214 and the second threaded hole and is threadedly connected to the adjusting nut 216, one end of the elastic member 214 abuts against the stepped surface of the stepped hole, and the other end abuts against the adjusting nut 216. When the driving cylinder 213 drives the second positioning block 22 to clamp the part to be detected 10, the elastic member 214 is compressed, and the elastic force of the elastic member 214 is converted into the elastic clamping force of the second positioning block 22, so that the second positioning block 22 is in elastic contact with the part to be detected 10, and the second positioning block 22 is prevented from being damaged by hard contact with the part to be detected 10. By rotating the adjusting nut 216 to control the distance between the adjusting nut 216 and the stepped surface, the compression amount of the elastic member 214 is adjusted to adjust the elastic force of the elastic member 214, and the appropriate elastic force is selected to accurately control the force of clamping the test piece 10.

[0063] In this embodiment, the elastic member 214 is a coil spring, the coil spring portion is located in the large diameter section of the stepped hole, one end of the spring abuts against the stepped surface of the stepped hole, and the other end abuts against the adjusting nut 216 .

[0064] Preferably, the two first positioning blocks 12 are respectively provided with a first arc surface 121, and the second positioning block 22 is provided with a second arc surface 221, and the second arc surface 221 and the two first arc surfaces 121 are used to clamp the side wall of the to-be-detected part 10. When placing the to-be-detected part 10, the support column 13 carries the to-be-detected part 10, and then the driving cylinder 213 drives the second arc surface 221 and the two first arc surfaces 121 to clamp the side wall of the to-be-detected part 10.

[0065] Since the wafer is provided with a notch for positioning, if the contact surface is a straight surface, when the notch contacts the straight surface, it will seriously affect the position of the wafer, causing the center of the wafer to deviate too much in the direction perpendicular to the first direction. In this embodiment, the first positioning block 12 and the second positioning block 22 are in contact with the part to be detected 10 at the arc surface. For an 8-inch wafer, the deviation of the wafer circle perpendicular to the first direction caused by the notch being located in the arc surface of the first positioning block 12 is less than 0.1 micron, so the adverse effect can be effectively reduced, and the centering accuracy of the wafer can be improved.

[0066] Preferably, a first guiding bevel 122 is provided at the top of the two first curved surfaces 121, and a second guiding bevel 222 is provided at the top of the second curved surface 221. Under the action of its own gravity, the wafer can fall into the second curved surface 221 and one side of the two first curved surfaces 121 along the guidance of the first guiding bevel 122 and the second guiding bevel 222 during the falling process.

[0067] During the wafer processing, the diameter of the same size of the test piece 10 (wafer) may be different due to processing errors. For example, the standard diameter of an 8-inch wafer is 200 mm, so the actual wafer diameter is within the error range of 199.800 mm-200.200 mm. The contact point positions of the test piece 10 with different diameters and the two first arc surfaces 121 are different; the larger the contact point distribution range, the larger the floating range of the angle between the contact point and the center of the circle, and the worse the three-point positioning accuracy. A larger contact surface can disperse the wear of the positioning contour, prevent damage to the wafer, and extend the life of the positioning block; the smaller the contact point distribution range, the smaller the floating range of the angle between the contact point and the center of the circle, and the better the three-point positioning accuracy. A smaller contact surface makes the wear of the positioning contour more concentrated, which is easy to damage the wafer and shortens the life of the positioning block.

[0068] In this embodiment, the angles between the two contact points of the smallest diameter part 10 to be detected (for example, the diameter of an 8-inch wafer with the smallest diameter is 199.8 mm) and the lines connecting the center of the part 10 to be detected are not less than 104°, and the angles between the two contact points of the largest diameter part 10 to be detected (for example, the diameter of an 8-inch wafer with the largest diameter is 200.2 mm) and the lines connecting the center of the part 10 to be detected are not greater than 136°, which meets the above-mentioned angle requirements and ensures the accuracy of detection and subsequent calibration of the part 10 to be detected.

[0069] like Figure 1-Figure 6 As shown, this embodiment also provides a wafer alignment method, using the above-mentioned wafer alignment mechanism, the wafer alignment method includes the following steps:

[0070] S1. Place the object to be inspected 10 on a carrying station; wherein, a robot 5 may be used to grab a wafer in a wafer box and place the wafer on a supporting column 13 of the carrying station.

[0071] S2, the driving component 21 drives the second positioning block 22 to clamp the part to be detected 10, and the second positioning block 22 contacts the detection end of the displacement sensor 3, and the displacement sensor 3 obtains the position information of the second positioning block 22; wherein, when the second positioning block 22 is pushed forward, since the two first positioning blocks 12 are symmetrically arranged and have the same curvature, the circular shape of the wafer is automatically corrected to the center line of the moving direction during the pushing process of the second positioning block 22. In this embodiment, the first direction is the X-axis, and the Y-axis is perpendicular to the first direction. After the circular shape of the wafer is pushed and calibrated, the center of the circle is on the X-axis, that is, the Y-axis coordinate value is 0, and the offset of the center of the circle detected by the subsequent position sensor is only the deflection from the preset center position in the X-axis direction, and the Y-axis is still 0.

[0072] S3, obtaining the diameter of the to-be-detected component 10 and the center offset of the to-be-detected component 10 according to the position information of the second positioning block 22;

[0073] S4. The carrying device 1 moves along the first direction to compensate for the center offset, so that the center of the to-be-detected component 10 moves to a preset position.

[0074] The wafer alignment method adopts a three-point positioning method, which can realize the carrying of the part to be detected 10, and set a displacement sensor 3 to accurately obtain the diameter information and position information of the part to be detected 10. The control system collects the output parameters of the displacement sensor 3, automatically adjusts its own position according to the collected data, and provides the diameter size of the wafer to the host system.

[0075] After step S4, the driving component 21 drives the second positioning to move away from the part to be inspected 10, and the control system sends the wafer diameter and precise positioning completion signal to the central controller, and the robot 5 transfers the wafer after precise centering and position compensation to other process positions.

[0076] Preferably, if Figure 3 , Figure 7 and Figure 8 As shown, in step S3, by comparing the detection information of the displacement sensor 3 with the database, the size of the wafer can be found quickly and easily, and the displacement compensation of the center position of the wafer can be performed, and the alignment accuracy can reach within 0.01mm. Among them, taking an 8-inch wafer with a standard diameter of 200.0mm and an allowable tolerance of the wafer diameter of ±0.2mm as an example, the following steps are used to establish the database:

[0077] S31. Establish a complete digital model in CAD software;

[0078] S32. In the digital model, the diameter of the wafer is set to be tangent to the second positioning block 22 and the two first positioning blocks 12; wherein, the diameter of the wafer varies between 199.8 mm and 200.2 mm, which drives the sliding block assembly to move forward and backward.

[0079] S33, set the reference plane, set the diameter of the standard wafer to the standard diameter, set the center offset to 0mm, and obtain the size △L1 of the center of the wafer relative to the reference plane, and the size △L2 of the contact point of the displacement sensor 3 relative to the reference plane; in this embodiment, the diameter of the wafer is set to 200.0mm, △L1 is 80.000mm, △L2 is 188.800mm, and the center offset is 0mm;

[0080] S34, gradually increase the set value of the wafer diameter from low to high, and obtain the slave values ​​of △L1, △L2 and the center offset, and record the wafer diameter, △L1, △L2 and the center offset in the database. In this embodiment, the wafer diameter setting value is sequentially increased from 199.8mm to 200.2mm, with each increment of 0.01mm, and the slave values ​​of △L1, △L2 and the center offset are repeatedly captured and recorded in the database respectively, and enough data corresponding information is obtained to obtain the following: Figure 8 The database shown.

[0081] Preferably, if Fig. 9 As shown, the wafer alignment mechanism needs to be calibrated before work, and the wafer alignment method also includes an accuracy verification method, which includes the following steps:

[0082] S10. Place a calibration piece of standard diameter between the second positioning block 22 and the two first positioning blocks 12, and control the second positioning block 22 to clamp the calibration piece; adjust the position of the abutment 23, and then adjust the front and rear positions of the contact surface of the displacement sensor 3, so that the contact surface stays in the middle position of the effective stroke of the displacement sensor 3, and sets the current position as the "zero position" of the displacement sensor 3 in the system; this embodiment uses a calibration piece with a standard diameter of 200.0 mm; in other embodiments, for other types of wafers (6 inches, 12 inches, etc.), their standard diameters shall prevail.

[0083] S20, respectively put in the calibration piece with the largest diameter and the calibration piece with the smallest diameter and clamp them in place, read the output parameters of the displacement sensor 3, compare the output parameters with the database for deviation values, and if the deviation values ​​are within the preset range, the accuracy verification method is completed. In this embodiment, the calibration piece with the largest diameter is 200.2 mm, the calibration piece with the smallest diameter is 199.8 mm, and the preset range is 0.008 mm.

[0084] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A wafer alignment mechanism, characterized in that: include: A carrying device (1), comprising a base plate (11) and two first positioning blocks (12), wherein the two first positioning blocks (12) are mounted on the base plate (11); A positioning device (2), comprising a driving component (21) and a second positioning block (22), wherein the driving component (21) is mounted on the base plate (11), the driving component (21) is drivingly connected to the second positioning block (22), the two first positioning blocks (12) are symmetrically arranged on both sides of the moving direction of the second positioning block (22), a bearing station is formed between the second positioning block (22) and the two first positioning blocks (12), the bearing station is used to bear the to-be-detected component (10), and the driving component (21) is used to drive the second positioning block (22) to move along the first direction so that the second positioning block (22) and the two first positioning blocks (12) clamp or loosen the to-be-detected component (10); A displacement sensor (3) is mounted on the bottom plate (11), and when the second positioning block (22) is pressed against the to-be-detected member (10), the second positioning block (22) can contact the detection end of the displacement sensor (3); A linear drive module (4), the linear drive module (4) is drivingly connected to the base plate (11), and the linear drive module (4) is used to drive the base plate (11) to move along the first direction.

2. The wafer alignment mechanism according to claim 1, characterized in that: The positioning device (2) further comprises a resisting member (23); the second positioning block (22) is provided with a first threaded hole extending along the first direction; the resisting member (23) is threadedly connected to the first threaded hole; and the end of the resisting member (23) can abut against the detection end of the displacement sensor (3).

3. The wafer alignment mechanism according to claim 1, characterized in that: The driving assembly (21) comprises a slide rail (211), a slider (212) and a driving cylinder (213); the slide rail (211) is arranged on the base plate (11); the slider (212) is arranged at the bottom of the second positioning block (22); the slider (212) is slidably connected to the slide rail (211); and the driving cylinder (213) is installed on the base plate (11) and drivingly connected to the second positioning block (22).

4. The wafer alignment mechanism according to claim 3, characterized in that: The driving assembly (21) further comprises an elastic member (214), an adjusting screw (215) and an adjusting nut (216); the second positioning block (22) is provided with a stepped hole; the output end of the driving cylinder (213) is provided with a second threaded hole; the adjusting screw (215) is sequentially passed through the small diameter section of the stepped hole, the large diameter section of the stepped hole, and the elastic member (214) and is threadedly connected to the adjusting nut (216) and the second threaded hole; one end of the elastic member (214) abuts against the stepped surface of the stepped hole, and the other end abuts against the adjusting nut (216).

5. The wafer alignment mechanism according to claim 1, characterized in that: The two first positioning blocks (12) are provided with a first arcuate surface (121), and the second positioning block (22) is provided with a second arcuate surface (221), and the second arcuate surface (221) and the two first arcuate surfaces (121) are used to clamp the side wall of the to-be-detected component (10).

6. The wafer alignment mechanism according to claim 5, characterized in that: The angles between the two contact points of the detected object (10) with the smallest diameter and the two first arc-shaped surfaces (121) and the lines connecting the center of the circle of the detected object (10) are not less than 104°; The angles between the two contact points of the detected object (10) with the largest diameter and the two first arc-shaped surfaces (121) and the lines connecting the center of the detected object (10) are not less than 136°.

7. The wafer alignment mechanism according to claim 1, characterized in that: A plurality of support columns (13) are arranged on the bottom plate (11), and the support columns (13) are used to support the to-be-detected component (10).

8. A wafer alignment method, characterized in that: Using the wafer alignment mechanism according to any one of claims 1 to 7, the wafer alignment method comprises the following steps: S1, placing the part to be tested (10) on a loading station; S2, the driving component (21) drives the second positioning block (22) to clamp the to-be-detected component (10), and the second positioning block (22) contacts the detection end of the displacement sensor (3), and the displacement sensor (3) obtains position information of the second positioning block (22); S3, obtaining the diameter of the to-be-detected component (10) and the center offset of the to-be-detected component (10) according to the position information of the second positioning block (22); S4. The carrying device (1) moves along a first direction to compensate for the center offset, so that the center of the to-be-detected component (10) moves to a preset position.

9. The wafer alignment method according to claim 8, characterized in that: In step S3, the detection information of the displacement sensor (3) is compared with the database to obtain the diameter of the to-be-detected part (10) and the center offset of the to-be-detected part (10); the following steps are used to establish the database: S31. Establish a complete digital model in CAD software; S32, in the digital model, setting the diameter of the wafer to be tangent to the second positioning block (22) and the two first positioning blocks (12); S33, setting a reference plane, setting the diameter of the wafer to a standard diameter, setting the center offset to 0 mm, and obtaining a size ΔL1 of the center of the wafer relative to the reference plane, and a size ΔL2 of the contact point of the displacement sensor (3) relative to the reference plane; S34, gradually increasing the setting value of the wafer diameter from low to high, and obtaining the slave values ​​of △L1, △L2 and the center offset, and recording the wafer diameter, △L1, △L2 and the center offset in the database respectively.

10. The wafer alignment method according to claim 9, characterized in that: The wafer alignment method further includes an accuracy verification method, and the accuracy verification method includes the following steps: S10, placing a calibration piece of standard diameter between the second positioning block (22) and the two first positioning blocks (12), and controlling the second positioning block (22) to clamp the calibration piece; adjusting the front and rear positions of the contact surface of the displacement sensor (3) so that the contact surface stays at the middle position of the effective stroke of the displacement sensor (3), and setting the current position as the "zero position" of the displacement sensor (3) in the system; S20, respectively placing the calibration piece with the largest diameter and the calibration piece with the smallest diameter and clamping them in place, reading the output parameters of the displacement sensor (3), comparing the output parameters with the database for deviation values, and completing the accuracy verification method if the deviation values ​​are within a preset range.

Images