Compensation calibration method and device for wafer chamfering processing

Abstract

The invention relates to the technical field of wafer processing equipment, in particular to a compensation calibration method and device for wafer chamfering processing. The compensation calibration method for wafer chamfering processing provided by the invention comprises the following steps: acquiring a target image; wherein the target image comprises a wafer table and a wafer arranged on the wafer table; determining the eccentricity of the center of the wafer table and the center of the wafer based on the target image; determining a second distance from the target processing point to the center of the wafer table based on the reference included angle and the eccentricity corresponding to the target processing point and the first distance; the error amount of an actual grinding point of the grinding groove and a preset grinding point is obtained; and the compensation amount during grinding of the target machining point is determined based on the first distance, the second distance and the error amount. Through compensation calibration, the machining precision is greatly improved, frequent manual calibration operation is omitted, the wafer incoming material error range can be narrowed, the total grinding amount is reduced, the machining efficiency is overall improved, and the rejection rate is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer processing equipment, and in particular to a compensation calibration method and device for wafer chamfering. Background Art

[0002] With the rapid development of China's semiconductor industry, the demand for the quantity and quality of wafers—the substrates of integrated circuits—is also increasing. Chamfering, a critical step in wafer manufacturing, prevents edge cracking during subsequent processing and reduces wear on polishing equipment. Existing chamfering machines first align the wafer's centering in a calibration unit before transferring it to the grinding chamber for processing. The default is for the wafer to be placed concentrically with the wafer table. However, wafers can drift during transfer and placement between the calibration unit and the grinding chamber. Traditionally, wafers have been designed to increase the error range of incoming wafers to cover any deviations during placement and handling, while also periodically performing manual calibration to ensure accurate positioning during repeated wafer transfers. This approach increases the amount of grinding, is time-consuming and labor-intensive, and impacts production efficiency. Furthermore, any deviation cannot be detected or corrected, resulting in wafer scrap. Summary of the Invention

[0003] The purpose of the present invention is to provide a compensation calibration method and device for wafer chamfering processing, so as to solve the technical problems that the grinding chamber of the existing chamfering machine has a large grinding amount during the wafer processing process, the manual calibration of the wafer position is time-consuming and labor-intensive, the production efficiency is low, and once an offset occurs, it cannot be detected and corrected, resulting in the scrapping of the wafer.

[0004] In a first aspect, the present invention provides a compensation calibration method for wafer chamfering, which is applied to a wafer chamfering device. The compensation calibration method includes: Acquire a target image; wherein the target image includes: a wafer stage and a wafer disposed on the wafer stage; determining an eccentricity between the center of the wafer table and the center of the wafer based on the target image; Determining a second distance from the target processing point to the center of the wafer table based on a reference angle corresponding to the target processing point, the eccentricity, and the first distance; wherein the reference angle represents the angle between a line connecting the target processing point to the center of the wafer table and a reference line; the reference line is a line connecting the center of the wafer table and a grinding point of the grinding groove; and the first distance is the distance from the target processing point to the center of the wafer; Obtaining the error between the actual grinding point of the grinding groove and the preset grinding point; A compensation amount when grinding the target processing point is determined based on the first distance, the second distance, and the error amount.

[0005] In an optional embodiment, the step of determining the eccentricity between the center of the wafer table and the center of the wafer based on the target image includes: Determine the coordinates of the wafer center in a preset reference coordinate system by a three-point measurement method; wherein the origin of the reference coordinate system is the center of the wafer stage; The straight-line distance from the coordinate of the wafer center to the origin is determined as the eccentricity.

[0006] In an optional embodiment, the step of determining the second distance from the target processing point to the center of the wafer table based on the reference angle corresponding to the target processing point, the eccentricity, and the first distance includes: determining the second distance using the following formula:

[0007] Wherein, r is the first distance; a2 is the eccentricity; b is the second distance; and θ is the reference angle corresponding to the target processing point.

[0008] In an optional embodiment, the step of determining the compensation amount during grinding of the target processing point based on the first distance, the second distance, and the error amount includes: The wafer feed direction is determined based on a magnitude relationship between the fifth distance and the second distance; if the fifth distance is greater than the second distance, the wafer feed direction is determined to be close to the grinding groove; if the fifth distance is less than the second distance, the wafer feed direction is determined to be away from the grinding groove; the fifth distance is the sum of the first distance and the error amount; The compensation amount is constrained by the following formula: a=│a1+rb│; Among them, a is the compensation amount; a1 is the error amount; r is the first distance; and b is the second distance.

[0009] In an optional embodiment, the processed edge of the wafer includes a straight edge; and the method further comprises: Determine the coordinates of the midpoint of the straight edge based on the coordinates of the center of the wafer and the coordinates of any two points on the straight edge in the reference coordinate system; Determine the distance from the coordinate of the midpoint of the straight edge to the center of the wafer table as a third distance; Determine the distance from the coordinate of the midpoint of the straight edge to the center of the wafer as a fourth distance; A compensation amount when grinding the target processing point is determined based on the third distance, the fourth distance, and the error amount.

[0010] In an optional embodiment, the step of determining the coordinates of the midpoint of the straight edge based on the coordinates of the wafer center and the coordinates of any two points on the straight edge in the reference coordinate system includes: Determine the equation of the line on which the straight edge lies as y = (y3-y2) / (x3-x2)×(x-x2)+y2; where (x2, y2) are the coordinates of the first point on the straight edge; and (x3, y3) are the coordinates of the second point on the straight edge. Determine that the equation of the straight line from the center of the wafer to the straight edge is y = -(x3-x2) / (y3-y2) × (x-x1) + y1; where (x1, y1) are the coordinates of the center of the wafer; Determine the coordinates (x4, y4) of the midpoint of the straight edge based on the equation of the straight line on which the straight edge is located and the equation of the straight line on which the perpendicular line from the center of the wafer to the straight edge is located; The third distance is determined by the following formula:

[0011] Wherein, c is the third distance.

[0012] In an optional embodiment, the step of determining the compensation amount during grinding of the target processing point based on the third distance, the fourth distance, and the error amount includes: The wafer feed direction is determined based on a magnitude relationship between the third distance and the sixth distance; if the third distance is greater than the sixth distance, the wafer feed direction is determined to be away from the grinding groove; if the third distance is less than the sixth distance, the wafer feed direction is determined to be close to the grinding groove; the sixth distance is the sum of the fourth distance and the error amount; The compensation amount is constrained by the following formula: a=│a1+dc│; Among them, a is the compensation amount; a1 is the error amount; c is the third distance; and d is the fourth distance.

[0013] In an optional embodiment, the step of obtaining the error between the actual grinding point of the grinding groove and the preset grinding point includes: Determine the single error based on the total grinding feed depth, the total loss of the grinding wheel in the radial direction, and the accumulated feed depth before the current wafer processing; The error amount is determined by sampling the single error multiple times and taking an average value.

[0014] In an optional embodiment, before the step of acquiring the target image, the compensation calibration method further includes: Obtaining the height of the wafer on the wafer stage; The Z-direction movement amount of the wafer table is determined based on the height of the wafer and the height of the grinding groove.

[0015] In a second aspect, the present invention provides a wafer chamfering processing device capable of implementing the compensation calibration method for wafer chamfering processing described in any one of the aforementioned embodiments, wherein the wafer chamfering processing device comprises: a feeding device, a CCD position detection sensor, a wafer grinding chamber, a wafer carrying device, a wafer grinding device, and a control module; The feeding device, the CCD position detection sensor and the wafer grinding device are respectively arranged in the wafer grinding chamber, the wafer carrying device is arranged on the feeding device, the wafer carrying device includes a rotatable wafer table, and the wafer grinding device includes a grinding wheel with grinding grooves; The feeding device, the CCD position detection sensor, the wafer carrying device and the wafer grinding device are respectively communicatively connected to the control module; The CCD position detection sensor is used to scan the target image, and the control module controls the feeding device to drive the wafer carrier device to move along the Y direction based on the first distance and the second distance determined by the target image and the error between the actual grinding point and the preset grinding point, so as to compensate and calibrate the compensation amount during wafer grinding.

[0016] Compared with the prior art, the compensation calibration method for wafer chamfering and the wafer chamfering device provided by the present invention have the following technical advantages: The compensation calibration method for wafer chamfering provided by the present invention is applied to a wafer chamfering processing device, and the compensation calibration method includes: acquiring a target image; wherein the target image includes: a wafer table and a wafer arranged on the wafer table; determining the eccentricity between the center of the wafer table and the center of the wafer based on the target image; determining the second distance from the target processing point to the center of the wafer table based on the reference angle and eccentricity corresponding to the target processing point and the first distance; wherein the reference angle represents the angle between the line connecting the target processing point to the center of the wafer table and the reference line; the reference line is the line connecting the center of the wafer table and the grinding point of the grinding groove; the first distance is the distance from the target processing point to the center of the wafer; acquiring the error between the actual grinding point of the grinding groove and the preset grinding point; and determining the compensation amount when grinding the target processing point based on the first distance, the second distance and the error amount.

[0017] Since the compensation amount during grinding of the target processing point is determined based on the first distance, the second distance and the error amount, the feed amount during grinding of the target processing point is the feed amount after automatic compensation calibration for the wafer offset and the error amount between the actual grinding point of the grinding groove and the preset grinding point. This not only eliminates the need for frequent manual calibration operations, but also adds grinding wheel loss compensation to the compensation parameters, which can monitor the wafer position at all times, greatly improve processing accuracy, and reduce scrap rate. Moreover, after the processing accuracy is improved, the allowable error range of the incoming material can be narrowed, the grinding removal amount is reduced, the processing time can be shortened, and the grinding wheel loss will also be reduced.

[0018] The wafer chamfering processing device provided by the present invention can realize the compensation calibration method of the above-mentioned wafer chamfering processing. Therefore, the technical advantages and effects achieved by it include the technical advantages and effects achieved by the above-mentioned compensation calibration method of wafer chamfering processing, which will not be elaborated here.

[0019] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 A schematic structural diagram of a wafer chamfering processing device provided in an embodiment of the present invention; Figure 2 A cross-sectional view of a wafer chamfering processing device provided by an embodiment of the present invention; Figure 3 This is a workflow diagram of the wafer chamfering processing device provided by an embodiment of the present invention.

[0022] Icons: 1-feeding device; 2-CCD position detection sensor; 3-wafer grinding chamber; 4-wafer carrying device; 5-wafer grinding device; 6-wafer table; 7-grinding wheel; 8-distance detection sensor; 9-grinding wheel spindle; 10-drive motor; 11-belt. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0026] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0027] The present invention will be further described in detail below through specific implementation examples in conjunction with the accompanying drawings.

[0028] This embodiment provides a compensation calibration method for wafer chamfering, which is applied to a wafer chamfering device. The compensation calibration method includes: Acquire a target image; wherein the target image includes: a wafer table 6 and a wafer disposed on the wafer table 6; determine the eccentricity between the center of the wafer table 6 and the center of the wafer based on the target image; determine the second distance from the target processing point to the center of the wafer table 6 based on the reference angle and eccentricity corresponding to the target processing point and the first distance; wherein the reference angle represents the angle between a line connecting the target processing point to the center of the wafer table 6 and a reference line; the reference line is a line connecting the center of the wafer table 6 and a grinding point of the grinding groove; the first distance is the distance from the target processing point to the center of the wafer; obtain the error between the actual grinding point of the grinding groove and the preset grinding point; determine the compensation amount when grinding the target processing point based on the first distance, the second distance and the error amount.

[0029] In this embodiment, since the compensation amount during grinding of the target processing point is determined based on the first distance, the second distance and the error amount, the feed amount during grinding of the target processing point is the feed amount after automatic compensation calibration of the wafer offset and the error amount between the actual grinding point of the grinding groove and the preset grinding point. This not only eliminates the need for frequent manual calibration operations, but also adds loss compensation for the grinding wheel 7 to the compensation parameters, which can monitor the wafer position at all times, greatly improve the processing accuracy, and reduce the scrap rate. Moreover, after the processing accuracy is improved, the allowable error range of the incoming material can be narrowed, the grinding removal amount is reduced, the processing time can be shortened, and the loss of the grinding wheel 7 will also be reduced.

[0030] In this embodiment, any point on the arc edge of the wafer can be the target processing point. The target image can be obtained by an industrial camera or other components that meet the requirements.

[0031] In the optional technical solution of this embodiment, the step of determining the eccentricity between the center of wafer stage 6 and the center of the wafer based on the target image includes: determining the coordinates of the wafer center in a preset reference coordinate system by a three-point measurement method; wherein the origin of the reference coordinate system is the center of wafer stage 6; and determining the straight-line distance from the coordinates of the wafer center to the origin as the eccentricity.

[0032] In this embodiment, based on the target image, the center of the wafer can be determined by randomly selecting three points on the arc edge of the wafer; a reference coordinate system is established with the center of the wafer stage 6 as the origin, and the Y axis of the reference coordinate system coincides with the reference line, and the X axis and the Y axis are in the same horizontal plane. The coordinates of the center of the wafer can be obtained, and the eccentricity can be determined by the distance from the coordinates of the center of the wafer to the origin. The method is simple and the eccentricity is easy to obtain.

[0033] In an optional technical solution of this embodiment, the step of determining the second distance from the target processing point to the center of the wafer table 6 based on the reference angle and eccentricity corresponding to the target processing point and the first distance includes: determining the second distance using the following formula: ; Among them, r is the first distance; a2 is the eccentricity; b is the second distance; θ is the reference angle corresponding to the target processing point.

[0034] In this embodiment, when processing the arc edge of the wafer, the wafer is rotated so that the wafer center, the center of the wafer table 6, and the grinding point are collinear, that is, the wafer center is located on the reference line. At this time, any point on the arc edge of the wafer (that is, the target processing point) is connected to the center of the wafer table 6. The angle formed by the connecting line and the reference line is recorded as θ, and the length of the connecting line is recorded as b. The connecting line, the wafer radius (that is, the first distance) and the line connecting the wafer center and the origin (that is, the eccentricity) form a triangle, where the wafer radius r is a known number. Through trigonometric functions The value of b can be calculated. The method is simple and the value of the second distance can be easily obtained.

[0035] In the optional technical solution of this embodiment, the step of determining the compensation amount when grinding the target processing point based on the first distance, the second distance and the error amount includes: determining the feed direction of the wafer based on the size relationship between the fifth distance and the second distance; wherein, if the fifth distance is greater than the second distance, the feed direction of the wafer is determined to be close to the grinding groove; if the fifth distance is less than the second distance, the feed direction of the wafer is determined to be away from the grinding groove; the fifth distance is the sum of the first distance and the error amount; the compensation amount is constrained by the following formula: a=│a1+rb│; wherein, a is the compensation amount; a1 is the error amount; r is the first distance; and b is the second distance.

[0036] In this embodiment, the coordinates of any point on the wafer's arc edge relative to the center of wafer table 6 can be represented by θ and b. During processing, when the wafer is rotated to a certain angle θ, if a1 + rb < 0, wafer table 6 moves away from grinding wheel 7 with a compensation amount of a = -[a1 + rb]. When a1 + rb > 0, wafer table 6 moves toward grinding wheel 7 with a compensation amount of a = a1 + rb. This method is simple and allows for easy determination of the wafer feed direction and compensation amount during arc edge processing.

[0037] In the optional technical solution of this embodiment, the processing edge of the wafer includes a straight edge; the method also includes: determining the coordinates of the midpoint of the straight edge based on the coordinates of the center of the wafer and the coordinates of any two points on the straight edge in the reference coordinate system; determining the distance from the coordinates of the midpoint of the straight edge to the center of the wafer table 6 as the third distance; determining the distance from the coordinates of the midpoint of the straight edge to the center of the wafer as the fourth distance; and determining the compensation amount when grinding the target processing point based on the third distance, the fourth distance and the error amount.

[0038] In this embodiment, when machining the straight edge of a wafer, the compensation amount is the same at any point on the straight edge. Since the compensation amount during straight edge grinding is determined based on the third distance, the fourth distance, and the error amount, the feed rate during straight edge grinding is the feed rate after automatic compensation and calibration for the wafer offset and the error between the actual grinding point of the grinding groove and the preset grinding point. This not only eliminates the need for frequent manual calibration operations, but also incorporates compensation for the wear of the grinding wheel 7 into the compensation parameters, allowing for constant monitoring of the wafer position, significantly improving machining accuracy and reducing scrap rates. Furthermore, with improved machining accuracy, the allowable error range of the incoming material can be narrowed, the amount of grinding removal can be reduced, machining time can be shortened, and wear of the grinding wheel 7 can be reduced. Furthermore, this method is applicable to machining wafers with complex shapes (e.g., multiple trimming edges).

[0039] In an optional technical solution of this embodiment, the step of determining the coordinates of the midpoint of the straight side based on the coordinates of the wafer center and the coordinates of any two points on the straight side in the reference coordinate system includes: determining that the equation of the straight line on which the straight side is located is y=(y3-y2) / (x3-x2)×(x-x2)+y2; wherein (x2, y2) are the coordinates of the first point on the straight side; (x3, y3) are the coordinates of the second point on the straight side; determining that the equation of the straight line on which the perpendicular line from the wafer center to the straight side is located is y=-(x3-x2) / (y3-y2)×(x-x1)+y1; wherein (x1, y1) are the coordinates of the wafer center; determining the coordinates of the midpoint of the straight side (x4, y4) based on the equation of the straight line on which the straight side is located and the equation of the straight line on which the perpendicular line from the wafer center to the straight side is located; and determining the third distance by the following formula: ; where c is the third distance.

[0040] In this embodiment, based on the target image, the coordinates (x2, y2) and (x3, y3) of any two points on the straight edge are obtained, and the equation of the straight line where the straight edge is located can be determined to be y=(y3-y2) / (x3-x2)×(x-x2)+y2. A perpendicular line is drawn through the center of the wafer, and the equation of the straight line where the perpendicular line is located is y=-(x3-x2) / (y3-y2)×(x-x1)+y1. The intersection of the two straight lines is the midpoint of the straight edge. The coordinates of the intersection can be obtained by combining the equations of the two lines, which is recorded as (x4, y4). The length of the connecting line from the center of wafer stage 6 to the midpoint of the straight edge is recorded as c, which can be obtained by the distance formula between the two points. The calculation shows that the method is simple and the coordinates of the midpoint of the straight side and the value of the third distance are easy to obtain.

[0041] In the optional technical solution of this embodiment, the step of determining the compensation amount when grinding the target processing point based on the third distance, the fourth distance and the error amount includes: determining the feed direction of the wafer based on the size relationship between the third distance and the sixth distance; wherein, if the third distance is greater than the sixth distance, the feed direction of the wafer is determined to be away from the grinding groove; if the third distance is less than the sixth distance, the feed direction of the wafer is determined to be close to the grinding groove; the sixth distance is the sum of the fourth distance and the error amount; the compensation amount is constrained by the following formula: a=│a1+dc│; wherein, a is the compensation amount; a1 is the error amount; c is the third distance; and d is the fourth distance.

[0042] In this embodiment, the distance from the wafer center to the midpoint of the straight edge is denoted as d, a known value. The wafer is rotated so that the midpoint of the straight edge coincides with the reference line. During machining, when a1 + dc < 0, wafer table 6 moves away from grinding wheel 7 with a compensation amount of a = -[a1 + dc]. When a1 + dc > 0, wafer table 6 moves toward grinding wheel 7 with a compensation amount of a = a1 + dc. Subsequently, wafer table 6 moves in the X direction to perform straight edge machining. This method is simple, and the wafer feed direction and compensation amount during straight edge machining are easily determined.

[0043] In the optional technical solution of this embodiment, the step of obtaining the error amount between the actual grinding point of the grinding groove and the preset grinding point includes: determining a single error based on the total grinding feed depth, the total loss of the radial length of the grinding wheel 7 and the accumulated feed depth before the current wafer processing; and determining the error amount by taking the average value of the single error by sampling multiple times.

[0044] In this embodiment, the error is calculated by averaging a large number of samples. Specifically, the total grinding feed depth is defined as M, the total radial length loss of the grinding wheel 7 is defined as N (N can be measured using laser light), and the grinding wheel 7 loss per unit feed depth is defined as L, where L = N / M. The cumulative feed depth before the current wafer is processed is defined as L1, and a1 = L1 × N / M. This method is simple, and the error is easily and accurately obtained.

[0045] However, this embodiment is not limited thereto, and the error amount a1 can also be obtained through laser measurement, acoustic wave measurement, and the like.

[0046] In an optional technical solution of this embodiment, before the step of acquiring the target image, the compensation calibration method further includes: acquiring the height of the wafer on the wafer table 6; and determining the Z-direction movement of the wafer table 6 based on the height of the wafer and the height of the grinding groove.

[0047] In this embodiment, by judging whether the height of the wafer on the wafer table 6 is the same as the height of the grinding groove, the movement direction and amount of the wafer table 6 in the Z direction are determined, so as to compensate and calibrate the height of the wafer during grinding, so that the wafer and the grinding groove are at the same height, greatly improving the processing accuracy and reducing the scrap rate.

[0048] The present embodiment provides a wafer chamfering processing device that can implement the above-mentioned compensation calibration method for wafer chamfering processing. Therefore, the technical advantages and effects achieved by the wafer chamfering processing device include the technical advantages and effects achieved by the above-mentioned compensation calibration method for wafer chamfering processing, which will not be repeated here.

[0049] like Figure 1 and Figure 2As shown, the wafer chamfering processing device includes: a feeding device 1, a CCD position detection sensor 2, a wafer grinding chamber 3, a wafer carrying device 4, a wafer grinding device 5 and a control module; the feeding device 1, the CCD position detection sensor 2 and the wafer grinding device 5 are respectively arranged in the wafer grinding chamber 3, the wafer carrying device 4 is arranged on the feeding device 1, the wafer carrying device 4 includes a rotatable wafer table 6, and the wafer grinding device 5 includes a grinding wheel 7 with grinding grooves; the feeding device 1, the CCD position detection sensor 2, the wafer carrying device 4 and the wafer grinding device 5 are respectively communicated with the control module; the CCD position detection sensor 2 is used to scan the target image, and the control module controls the feeding device 1 to drive the wafer carrying device 4 to move along the Y direction based on the first distance and the second distance determined by the target image and the error amount between the actual grinding point and the preset grinding point, so as to compensate and calibrate the compensation amount during wafer grinding.

[0050] Furthermore, the wafer chamfering processing device also includes a distance detection sensor 8, which is arranged in the wafer grinding chamber 3, and the distance detection sensor 8 is communicatively connected to the control module; the distance detection sensor 8 is used to detect the height of the wafer on the wafer table 6, and the control module controls the feeding device 1 to drive the wafer carrier 4 to move along the Z direction based on the height of the wafer and the height of the grinding groove, so as to compensate and calibrate the height of the wafer during grinding.

[0051] Furthermore, the feeding device 1 is a three-axis feeding device 1, which can realize feeding movement of the wafer in three directions: horizontal X-axis, Y-axis and vertical Z-axis, and can realize grinding of arc edges and straight edges of the wafer, thereby improving applicability.

[0052] Furthermore, the three-axis feeding device 1 includes an X-axis motion mechanism, a Y-axis motion mechanism, a Z-axis motion mechanism and a constant force spring; the X-axis motion mechanism, the Y-axis motion mechanism and the Z-axis motion mechanism all include a motor, a lead screw and a nut seat, and the motor is connected to the lead screw for transmission, and the nut seat is arranged on the lead screw; at least one of the X-axis motion mechanism, the Y-axis motion mechanism and the Z-axis motion mechanism is provided with a constant force spring, which is used to apply a force along the axial direction of the lead screw to the nut seat.

[0053] In this embodiment, the Z-axis motion mechanism and the X-axis motion mechanism as a whole can be driven by the Y-axis motion mechanism to move in the Y direction, the X-axis motion mechanism can be driven by the Z-axis motion mechanism to move in the Z direction, and the X-axis motion mechanism is finally installed to drive the wafer carrier 4 to move in the X direction. Each axis motion mechanism uses a servo motor to transmit power through a ball screw. The X-axis motion mechanism is guided by a linear guide for easy installation. The Z-axis motion mechanism and the X-axis motion mechanism need to have a compact structure and are guided by a cross roller guide, and the high rigidity of this type of guide is used to ensure motion accuracy. The Z-axis motion mechanism and the X-axis motion mechanism use machine tool processing methods to ensure the verticality of the installation reference to ensure accurate positioning. A constant force spring is added to each motion axis motion mechanism to eliminate the return clearance of the screw due to long-term use, thereby ensuring the long-term accuracy and reliability of the equipment.

[0054] Furthermore, the wafer grinding device 5 also includes a grinding wheel spindle 9, a drive motor 10, a belt 11, and a cooling mechanism. The grinding wheel 7 is connected to the grinding wheel spindle 9, and the drive motor 10 is connected to the grinding wheel spindle 9 via the belt 11. The cooling mechanism is provided on the grinding wheel spindle 9. The drive motor 10 and the grinding wheel spindle 9 are connected by the belt 11 to isolate heat transfer. At the same time, the cooling mechanism provided on the grinding wheel spindle 9 can further reduce heat transfer and ensure the reliability of wafer processing. The cooling mechanism can be water cooling or other cooling methods, as long as it meets the requirements.

[0055] like Figure 3 As shown, the specific processing workflow of this embodiment is as follows: S1, start; S2, the distance detection sensor 8 detects the height of the wafer; S3, check whether the wafer and the grinding groove are at the same height; if not, adjust the wafer height along the Z direction to the same height position and then perform the CCD position detection sensor 2 to scan the target image; if so, directly perform the CCD position detection sensor 2 to scan the target image; S4, calibrating whether the wafer and the center of the wafer stage 6 are concentric; if not, calculating the corresponding distance the wafer needs to move in the Y direction and the error between the actual grinding point of the grinding groove and the preset grinding point, and obtaining the compensation amount; if so, calculating the error between the actual grinding point of the grinding groove and the preset grinding point, and obtaining the compensation amount; S5, generating a wafer feeding route and a position of the wafer on the CCD position detection sensor 2 according to the compensation amount; S6, the wafer is fed according to the wafer feeding route; S7, the CCD position detection sensor 2 monitors the wafer position. If there is a slight deviation, the wafer position is corrected; if there is a serious deviation, an alarm is issued and grinding is terminated; if there is no deviation, normal feeding is carried out.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A compensation calibration method for wafer chamfering, characterized in that: Applied to a wafer chamfering processing device, the compensation calibration method includes: Acquiring a target image; wherein the target image includes: a wafer table (6) and a wafer disposed on the wafer table (6); Determining the eccentricity between the center of the wafer table (6) and the center of the wafer based on the target image; The second distance from the target processing point to the center of the wafer table (6) is determined based on the reference angle corresponding to the target processing point, the eccentricity, and the first distance; wherein the reference angle represents the angle between the line connecting the target processing point to the center of the wafer table (6) and the reference line; the reference line is the line connecting the center of the wafer table (6) and the grinding point of the grinding groove; the first distance is the distance from the target processing point to the center of the wafer; Obtaining the error between the actual grinding point of the grinding groove and the preset grinding point; A compensation amount when grinding the target processing point is determined based on the first distance, the second distance, and the error amount.

2. The compensation calibration method for wafer chamfering according to claim 1, characterized in that: The step of determining the eccentricity between the center of the wafer table (6) and the center of the wafer based on the target image comprises: Determine the coordinates of the wafer center in a preset reference coordinate system by a three-point measurement method; wherein the origin of the reference coordinate system is the center of the wafer stage (6); The straight-line distance from the coordinate of the wafer center to the origin is determined as the eccentricity.

3. The compensation calibration method for wafer chamfering according to claim 2, wherein: The step of determining the second distance from the target processing point to the center of the wafer table (6) based on the reference angle corresponding to the target processing point, the eccentricity and the first distance includes: determining the second distance by the following formula: Wherein, r is the first distance; a2 is the eccentricity; b is the second distance; and θ is the reference angle corresponding to the target processing point.

4. The compensation calibration method for wafer chamfering according to claim 3, characterized in that: The step of determining the compensation amount when grinding the target processing point based on the first distance, the second distance, and the error amount includes: The wafer feed direction is determined based on a magnitude relationship between a fifth distance and the second distance; if the fifth distance is greater than the second distance, the wafer feed direction is determined to be close to the grinding groove; if the fifth distance is less than the second distance, the wafer feed direction is determined to be away from the grinding groove; the fifth distance is the sum of the first distance and the error amount; The compensation amount is constrained by the following formula: a=│a1+rb│; Among them, a is the compensation amount; a1 is the error amount; r is the first distance; and b is the second distance.

5. The compensation calibration method for wafer chamfering according to claim 2, wherein: The processed edge of the wafer includes a straight edge; the method further includes: Determine the coordinates of the midpoint of the straight edge based on the coordinates of the center of the wafer and the coordinates of any two points on the straight edge in the reference coordinate system; Determine the distance from the coordinate of the midpoint of the straight edge to the center of the wafer table (6) as a third distance; Determine the distance from the coordinate of the midpoint of the straight edge to the center of the wafer as a fourth distance; A compensation amount when grinding the target processing point is determined based on the third distance, the fourth distance, and the error amount.

6. The compensation calibration method for wafer chamfering according to claim 5, characterized in that: The step of determining the coordinates of the midpoint of the straight edge based on the coordinates of the wafer center and the coordinates of any two points on the straight edge in the reference coordinate system comprises: Determine the equation of the line on which the straight edge lies as y = (y3-y2) / (x3-x2)×(x-x2)+y2; where (x2, y2) are the coordinates of the first point on the straight edge; and (x3, y3) are the coordinates of the second point on the straight edge. Determine that the equation of the straight line from the center of the wafer to the straight edge is y = -(x3-x2) / (y3-y2) × (x-x1) + y1; where (x1, y1) are the coordinates of the center of the wafer; Determine the coordinates (x4, y4) of the midpoint of the straight edge based on the equation of the straight line on which the straight edge is located and the equation of the straight line on which the perpendicular line from the center of the wafer to the straight edge is located; The third distance is determined by the following formula: Wherein, c is the third distance.

7. The compensation calibration method for wafer chamfering according to claim 6, characterized in that: The step of determining the compensation amount when grinding the target processing point based on the third distance, the fourth distance and the error amount includes: The wafer feed direction is determined based on the magnitude relationship between the third distance and the sixth distance; if the third distance is greater than the sixth distance, the wafer feed direction is determined to be away from the grinding groove; if the third distance is less than the sixth distance, the wafer feed direction is determined to be close to the grinding groove; the sixth distance is the sum of the fourth distance and the error amount; The compensation amount is constrained by the following formula: a=│a1+dc│; Among them, a is the compensation amount; a1 is the error amount; c is the third distance; and d is the fourth distance.

8. The compensation calibration method for wafer chamfering according to claim 1, wherein: The step of obtaining the error between the actual grinding point of the grinding groove and the preset grinding point includes: Determine a single error based on the total grinding feed depth, the total loss of the grinding wheel (7) in the radial direction, and the accumulated feed depth before the current wafer is processed; The error amount is determined by sampling the single error multiple times and taking an average value.

9. The compensation calibration method for wafer chamfering according to claim 1, wherein: Before the step of acquiring the target image, the compensation calibration method further includes: Obtaining the height of the wafer on the wafer table (6); The Z-direction movement amount of the wafer table (6) is determined based on the height of the wafer and the height of the grinding groove.

10. A wafer chamfering processing device, characterized in that: A compensation calibration method for wafer chamfering processing capable of realizing any one of claims 1 to 9, wherein the wafer chamfering processing device comprises: a feeding device (1), a CCD position detection sensor (2), a wafer grinding chamber (3), a wafer carrying device (4), a wafer grinding device (5) and a control module; The feeding device (1), the CCD position detection sensor (2) and the wafer grinding device (5) are respectively arranged in the wafer grinding chamber (3); the wafer carrying device (4) is arranged on the feeding device (1); the wafer carrying device (4) includes a rotatable wafer table (6); and the wafer grinding device (5) includes a grinding wheel (7) with grinding grooves; The feeding device (1), the CCD position detection sensor (2), the wafer carrying device (4) and the wafer grinding device (5) are respectively connected to the control module for communication; The CCD position detection sensor (2) is used to scan a target image, and the control module controls the feeding device (1) to drive the wafer carrying device (4) to move along the Y direction based on the first distance and the second distance determined by the target image and the error between the actual grinding point and the preset grinding point, so as to perform compensation calibration for the compensation amount during wafer grinding.

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