A compensation calibration method and apparatus for wafer chamfering.

Abstract

This invention relates to the field of wafer processing equipment technology, and in particular to a compensation calibration method and apparatus for wafer chamfering. The compensation calibration method for wafer chamfering provided by this invention includes: acquiring a target image; wherein the target image includes: a wafer stage and a wafer disposed on the wafer stage; determining the eccentricity between the center of the wafer stage 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 stage based on the reference angle corresponding to the target processing point, the eccentricity, and a first distance; acquiring the error between the actual grinding point and a preset grinding point in the grinding groove; and determining the compensation amount during grinding of the target processing point based on the first distance, the second distance, and the error amount. Through compensation calibration, processing accuracy is greatly improved, not only eliminating frequent manual calibration operations but also reducing the range of incoming wafer errors, decreasing the total grinding amount, improving overall processing efficiency, and reducing the scrap rate.

Description

Technical Field

[0001] This invention relates to the field of wafer processing equipment technology, and in particular to a compensation calibration method and apparatus for wafer chamfering. Background Technology

[0002] With the rapid development of China's semiconductor industry, the quantity and quality requirements for wafers—the carriers of integrated circuits—are constantly increasing. Chamfering, a crucial step in wafer manufacturing, prevents edge breakage during subsequent processing and reduces wear on polishing equipment. In existing chamfering machines, the wafer is first aligned in a calibration unit before being transferred to the grinding chamber for processing. It is generally assumed that the wafer is concentric with the wafer stage after being placed on it. However, in reality, wafer misalignment can occur during the transfer and handling process from the calibration unit to the grinding chamber. The traditional approach is to increase the wafer's incoming material error range to cover the deviations during handling, while 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, impacts production efficiency, and if misalignment occurs, it cannot be detected and corrected, leading to wafer scrap. Summary of the Invention

[0003] The purpose of this invention is to provide a compensation calibration method and apparatus for wafer chamfering, in order to solve the technical problems of existing chamfering machines in wafer processing, such as large grinding volume, time-consuming and labor-intensive manual calibration of wafer placement and removal positions, low production efficiency, and inability to detect and correct any deviations, leading to wafer scrap.

[0004] In a first aspect, the present invention provides a compensation calibration method for wafer chamfering, applied to a wafer chamfering apparatus, the compensation calibration method comprising:

[0005] Acquire a target image; wherein the target image includes: a wafer stage and a wafer disposed on the wafer stage;

[0006] The eccentricity between the center of the wafer stage and the center of the wafer is determined based on the target image;

[0007] The second distance from the target processing point to the center of the wafer stage 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 stage and the reference line; the reference line is the line connecting the center of the wafer stage 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.

[0008] Obtain the error between the actual grinding point and the preset grinding point in the grinding groove;

[0009] The compensation amount during grinding of the target machining point is determined based on the first distance, the second distance, and the error amount.

[0010] In an optional implementation, the step of determining the eccentricity between the wafer abutment center and the wafer center based on the target image includes:

[0011] The coordinates of the wafer center in a preset reference coordinate system are determined by a three-point measurement method; wherein the origin of the reference coordinate system is the center of the wafer stage.

[0012] The straight-line distance from the coordinates of the wafer center to the origin is defined as the eccentricity.

[0013] In an optional implementation, the step of determining the second distance from the target processing point to the center of the wafer abutment 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:

[0014]

[0015] Where 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.

[0016] In an optional implementation, the step of determining the compensation amount during grinding of the target machining point based on the first distance, the second distance, and the error amount includes:

[0017] The wafer feed direction is determined based on the relationship between the fifth distance and the second distance; wherein, if the fifth distance is greater than the second distance, the wafer feed direction is determined to be closer to the grinding groove; if the fifth distance is less than the second distance, the wafer feed direction is determined to be farther from the grinding groove; the fifth distance is the sum of the first distance and the error amount;

[0018] The compensation amount is constrained by the following formula:

[0019] a = |a1+rb|;

[0020] Where a is the compensation amount; a1 is the error amount; r is the first distance; and b is the second distance.

[0021] In an optional embodiment, the processed edge of the wafer includes a straight edge; the method further includes:

[0022] The coordinates of the midpoint of the straight edge are determined based on the coordinates of the wafer center and the coordinates of any two points on the straight edge in the reference coordinate system.

[0023] The distance from the coordinates of the midpoint of the straight edge to the center of the wafer stage is defined as the third distance;

[0024] The distance from the coordinates of the midpoint of the straight edge to the center of the wafer is defined as the fourth distance;

[0025] The compensation amount during grinding of the target machining point is determined based on the third distance, the fourth distance, and the error amount.

[0026] In an optional implementation, 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:

[0027] The equation of the line containing the right edge is determined as y = (y3 - y2) / (x3 - x2) × (x - x2) + y2; where (x2, y2) are the coordinates of the first point on the right edge; and (x3, y3) are the coordinates of the second point on the right edge.

[0028] The equation of the line perpendicular from the wafer center to the straight edge is determined as y = -(x3-x2) / (y3-y2)×(x-x1)+y1; where (x1, y1) are the coordinates of the wafer center.

[0029] The coordinates (x4, y4) of the midpoint of the straight edge are determined based on the equation of the line containing the straight edge and the equation of the line containing the perpendicular line from the wafer center to the straight edge.

[0030] The third distance is determined by the following formula:

[0031]

[0032] Where c is the third distance.

[0033] In an optional implementation, the step of determining the compensation amount during grinding of the target machining point based on the third distance, the fourth distance, and the error amount includes:

[0034] The wafer feed direction is determined based on the relationship between the third distance and the sixth distance; wherein, 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 closer to the grinding groove; the sixth distance is the sum of the fourth distance and the error amount;

[0035] The compensation amount is constrained by the following formula:

[0036] a = |a1+dc|;

[0037] Where a is the compensation amount; a1 is the error amount; c is the third distance; and d is the fourth distance.

[0038] In an optional implementation, the step of obtaining the error between the actual grinding point and the preset grinding point of the grinding groove includes:

[0039] The single-shot error is determined based on the total grinding feed depth, the total length loss in the radius direction of the grinding wheel, and the cumulative feed depth before the current wafer processing.

[0040] The error amount is determined by averaging the single error from multiple samplings.

[0041] In an optional implementation, prior to the step of acquiring the target image, the compensation calibration method further includes:

[0042] Obtain the height of the wafer on the wafer stage;

[0043] The Z-axis motion of the wafer stage is determined based on the height of the wafer and the height of the grinding groove.

[0044] Secondly, the present invention provides a wafer chamfering processing apparatus, which can realize the compensation and calibration method for wafer chamfering processing described in any of the foregoing embodiments. The wafer chamfering processing apparatus includes: a feeding device, a CCD position detection sensor, a wafer grinding cavity, a wafer carrier device, a wafer grinding device, and a control module.

[0045] The feeding device, the CCD position detection sensor, and the wafer grinding device are respectively disposed in the wafer grinding cavity. The wafer carrier device is disposed on the feeding device. The wafer carrier device includes a rotatable wafer stage. The wafer grinding device includes a grinding wheel with grinding grooves.

[0046] The feeding device, the CCD position detection sensor, the wafer carrier device, and the wafer grinding device are all communicatively connected to the control module.

[0047] The CCD position detection sensor is used to scan the target image. The control module controls the feed 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 the wafer grinding.

[0048] Compared with the prior art, the technical advantages of the compensation calibration method and wafer chamfering apparatus provided by the present invention are as follows:

[0049] The present invention provides a compensation and calibration method for wafer chamfering, applied to a wafer chamfering apparatus. The compensation and calibration method includes: acquiring a target image; wherein the target image includes a wafer stage and a wafer disposed on the wafer stage; determining the eccentricity between the center of the wafer stage 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 stage based on a reference angle corresponding to the target processing point, the eccentricity, and a first distance; wherein the reference angle represents the angle between the line connecting the target processing point to the center of the wafer stage and a reference line; the reference line is the line connecting the center of the wafer stage and the grinding point of the grinding tank; 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 and the preset grinding point of the grinding tank; and determining the compensation amount during grinding of the target processing point based on the first distance, the second distance, and the error amount.

[0050] 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 and calibration of the wafer offset and the error amount between the actual grinding point and the preset grinding point of the grinding groove. This not only eliminates frequent manual calibration operations, but also incorporates grinding wheel wear compensation into the compensation parameters, which can monitor the wafer position in real time, greatly improve processing accuracy, reduce scrap rate, and after the processing accuracy is improved, the allowable error range of the incoming material can be reduced, the amount removed by grinding can be reduced, the processing time can be shortened, and the wear of the grinding wheel will also be reduced.

[0051] The wafer chamfering apparatus provided by the present invention can realize the above-mentioned compensation and calibration method for wafer chamfering. Therefore, the technical advantages and effects achieved by it include the technical advantages and effects achieved by the above-mentioned compensation and calibration method for wafer chamfering, which will not be elaborated here.

[0052] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0053] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0054] Figure 1 This is a schematic diagram of the wafer chamfering processing apparatus provided in an embodiment of the present invention;

[0055] Figure 2 This is a cross-sectional view of the wafer chamfering processing apparatus provided in an embodiment of the present invention;

[0056] Figure 3This is a flowchart illustrating the process of wafer chamfering processing equipment provided in an embodiment of the present invention.

[0057] Icons: 1-Feed device; 2-CCD position detection sensor; 3-Wafer grinding chamber; 4-Wafer carrier; 5-Wafer grinding device; 6-Wafer stage; 7-Grinding wheel; 8-Distance detection sensor; 9-Grinding wheel spindle; 10-Drive motor; 11-Belt. Detailed Implementation

[0058] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the 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.

[0060] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0061] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0062] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0063] This embodiment provides a compensation and calibration method for wafer chamfering, applied to a wafer chamfering apparatus. The compensation and calibration method includes:

[0064] Acquire a target image; wherein the target image includes: a wafer stage 6 and a wafer disposed on the wafer stage 6; determine the eccentricity between the center of the wafer stage 6 and the center of the wafer based on the target image; determine a second distance from the target processing point to the center of the wafer stage 6 based on the reference angle corresponding to the target processing point, the eccentricity, and a first distance; wherein the reference angle represents the angle between the line connecting the target processing point to the center of the wafer stage 6 and the reference line; the reference line is the line connecting the center of the wafer stage 6 and the grinding point of the grinding tank; the first distance is the distance from the target processing point to the center of the wafer; acquire the error between the actual grinding point and the preset grinding point of the grinding tank; determine the compensation amount during grinding of the target processing point based on the first distance, the second distance, and the error amount.

[0065] 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 and calibration of the wafer offset and the error amount between the actual grinding point and the preset grinding point of the grinding groove. This not only eliminates frequent manual calibration operations, but also adds wear compensation of the grinding wheel 7 to the compensation parameters, which can monitor the wafer position in real time, greatly improve the processing accuracy, reduce the scrap rate, and after the processing accuracy is improved, the allowable error range of the incoming material can be reduced, the amount removed by grinding is reduced, the processing time can be shortened, and the wear of the grinding wheel 7 will also be reduced.

[0066] In this embodiment, any point on the arc edge of the wafer can be the target processing point. The target image can be acquired using an industrial camera or other components that meet the requirements.

[0067] In the optional technical solution of this embodiment, the step of determining the eccentricity between the center of the 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 means of a three-point measurement method; wherein the origin of the reference coordinate system is the center of the wafer stage 6; and determining the straight-line distance from the coordinates of the wafer center to the origin as the eccentricity.

[0068] In this embodiment, based on the target image, the center of the wafer can be determined by taking any 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 Y-axis are on the same horizontal plane. The coordinates of the wafer center can be obtained. The eccentricity can be determined by the distance from the coordinates of the wafer center to the origin. The method is simple and the eccentricity is easy to obtain.

[0069] In the optional technical solution of this embodiment, the step of determining the second distance from the target processing point to the center of the wafer stage 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: Where 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.

[0070] In this embodiment, during the processing of the arc edge of the wafer, the wafer is rotated so that the wafer center, the center of wafer stage 6, and the grinding point are collinear, i.e., the wafer center is located on the reference line. At this time, any point on the arc edge of the wafer (i.e., the target processing point) is connected to the center of wafer stage 6. The angle between the connecting line and the reference line is denoted as θ, and the length of the connecting line is denoted as b. The connecting line, the wafer radius (i.e., the first distance), and the line connecting the wafer center and the origin (i.e., the eccentricity) form a triangle, where the wafer radius r is a known value, obtained through trigonometric functions. The value of b can be calculated. The method is simple, and the value of the second distance is easy to obtain.

[0071] In the optional technical solution of this embodiment, the step of determining the compensation amount during grinding of the target machining point based on the first distance, the second distance, and the error amount includes: determining the wafer feed direction based on the relationship between the fifth distance and the second distance; wherein, if the fifth distance is greater than the second distance, the wafer feed direction is determined to be closer to the grinding groove; if the fifth distance is less than the second distance, the wafer feed direction is determined to be farther 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│; where a is the compensation amount; a1 is the error amount; r is the first distance; and b is the second distance.

[0072] In this embodiment, the coordinates of any point on the arc edge of the wafer relative to the center of the wafer stage 6 can be represented by θ and b. During processing, when the wafer rotates to a certain angle θ, if a1 + rb < 0, the wafer stage 6 moves away from the grinding wheel 7, with a compensation amount of a = -[a1 + rb]. If a1 + rb > 0, the wafer stage 6 moves towards the grinding wheel 7, with a compensation amount of a = a1 + rb. The method is simple, and the feed direction and compensation amount of the wafer during arc edge processing are easy to obtain.

[0073] In the optional technical solution of this embodiment, the processing edge of the wafer includes a straight edge; the method further includes: 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; determining the distance from the coordinates of the midpoint of the straight edge to the center of the wafer stage 6 as a third distance; determining the distance from the coordinates of the midpoint of the straight edge to the wafer center as a fourth distance; and determining the compensation amount during grinding of the target processing point based on the third distance, the fourth distance and the error amount.

[0074] In this embodiment, during the straight-edge processing of the 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 of the wafer offset and the error between the actual grinding point and the preset grinding point of the grinding groove. This not only eliminates frequent manual calibration operations but also incorporates wear compensation for the grinding wheel 7 into the compensation parameters, allowing for real-time monitoring of the wafer position, greatly improving processing accuracy, reducing scrap rate, and reducing the allowable error range of the incoming material after improving processing accuracy. This reduces the amount of material removed during grinding, shortens the processing time, and also reduces the wear of the grinding wheel 7. Furthermore, this method is applicable to the processing of wafers with complex shapes (such as multiple diced edges).

[0075] In the optional technical solution of this 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: determining the equation of the straight line containing the straight edge as y = (y3-y2) / (x3-x2)×(x-x2)+y2; where (x2, y2) are the coordinates of the first point on the straight edge; (x3, y3) are the coordinates of the second point on the straight edge; determining the equation of the straight line containing the perpendicular line from the wafer center to the straight edge as y = -(x3-x2) / (y3-y2)×(x-x1)+y1; where (x1, y1) are the coordinates of the wafer center; determining the coordinates (x4, y4) of the midpoint of the straight edge based on the equation of the straight line containing the straight edge and the equation of the straight line containing the perpendicular line from the wafer center to the straight edge; and determining the third distance using the following formula: Where c is the third distance.

[0076] 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. The equation of the straight line containing the straight edge can be determined as y = (y3-y2) / (x3-x2)×(x-x2)+y2. A perpendicular line is drawn from the center of the wafer to this line. The equation of the line containing this perpendicular line is y = -(x3-x2) / (y3-y2)×(x-x1)+y1. The intersection of the two lines is the midpoint of the straight edge. Solving the equations of the two lines simultaneously, the coordinates of the intersection point can be obtained, denoted as (x4, y4). The length of the line connecting the center of wafer stage 6 to the midpoint of the straight edge is denoted as c. c can be obtained from the distance formula between two points. The calculation shows that the method is simple, and the coordinates of the midpoint of the straight edge and the value of the third distance are easy to obtain.

[0077] In the optional technical solution of this embodiment, the step of determining the compensation amount during grinding of the target machining point based on the third distance, the fourth distance, and the error amount includes: determining the wafer feed direction based on the relationship between the third distance and the sixth distance; wherein, 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 closer 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│; where a is the compensation amount; a1 is the error amount; c is the third distance; and d is the fourth distance.

[0078] In this embodiment, the distance from the wafer center to the midpoint of the straight edge is denoted as d, which is a known value. The wafer is rotated so that the midpoint of the straight edge coincides with the baseline. During processing, when a1 + dc < 0, the wafer stage 6 moves away from the grinding wheel 7, with a compensation amount of a = -[a1 + dc]. When a1 + dc > 0, the wafer stage 6 moves towards the grinding wheel 7, with a compensation amount of a = a1 + dc. Subsequently, the wafer stage 6 moves in the X direction to perform straight edge processing. The method is simple, and the feed direction and compensation amount of the wafer during straight edge processing are easy to obtain.

[0079] In the optional technical solution of this embodiment, the step of obtaining the error between the actual grinding point and the preset grinding point of the grinding groove includes: determining the single error based on the total grinding feed depth, the total loss of the radius length of the grinding wheel 7, and the cumulative feed depth before the current wafer processing; and determining the error by taking the average value of multiple single errors.

[0080] 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 wear of the grinding wheel 7 in the radial direction is defined as N (the value of N can be obtained by laser measurement), the wear of the grinding wheel 7 per unit feed depth is defined as L, then L=N / M, and the cumulative feed depth before the current wafer processing is defined as L1, then a1=L1×N / M. The method is simple, and the error is easy and accurate to obtain.

[0081] However, this embodiment is not limited to this; the error a1 can also be obtained by laser measurement, acoustic wave measurement, etc.

[0082] In the 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 stage 6; and determining the Z-axis motion of the wafer stage 6 based on the height of the wafer and the height of the grinding groove.

[0083] In this embodiment, by determining whether the height of the wafer on the wafer stage 6 is equal to the height of the grinding groove, the movement direction and amount of the wafer stage 6 in the Z direction are determined, so as to compensate and calibrate the height during wafer grinding, so that the wafer and the grinding groove are at the same height, which greatly improves the processing accuracy and reduces the scrap rate.

[0084] The wafer chamfering processing apparatus provided in this embodiment can realize the above-mentioned compensation and calibration method for wafer chamfering processing. Therefore, the technical advantages and effects achieved by the wafer chamfering processing apparatus include the technical advantages and effects achieved by the above-mentioned compensation and calibration method for wafer chamfering processing, which will not be repeated here.

[0085] like Figure 1 and Figure 2 As shown, the wafer chamfering processing apparatus includes: a feed device 1, a CCD position detection sensor 2, a wafer grinding cavity 3, a wafer carrier 4, a wafer grinding device 5, and a control module; the feed device 1, the CCD position detection sensor 2, and the wafer grinding device 5 are respectively disposed in the wafer grinding cavity 3, the wafer carrier 4 is disposed on the feed device 1, the wafer carrier 4 includes a rotatable wafer stage 6, and the wafer grinding device 5 includes a grinding wheel 7 with grinding grooves; the feed device 1, the CCD position detection sensor 2, the wafer carrier 4, and the wafer grinding device 5 are respectively communicatively connected to the control module; the CCD position detection sensor 2 is used to scan the target image, and the control module controls the feed device 1 to drive the wafer carrier 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 compensate and calibrate the compensation amount during wafer grinding.

[0086] Furthermore, the wafer chamfering processing device also includes a distance detection sensor 8, which is disposed in the wafer grinding cavity 3 and is communicatively connected to the control module. The distance detection sensor 8 is used to detect the height of the wafer on the wafer stage 6. The control module controls the feed device 1 to drive the wafer carrier device 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 during wafer grinding.

[0087] Furthermore, the feed device 1 is a three-axis feed device 1, which can realize feed motion in three directions: horizontal X-axis, Y-axis and vertical Z-axis of the wafer, and can realize grinding of the arc edge and straight edge of the wafer, thus improving applicability.

[0088] Furthermore, the three-axis feed device 1 includes an X-axis motion mechanism, a Y-axis motion mechanism, a Z-axis motion mechanism, and a constant force spring; each of the X-axis motion mechanism, the Y-axis motion mechanism, and the Z-axis motion mechanism includes a motor, a lead screw, and a nut seat, and the motor is connected to the lead screw via a transmission, and the nut seat is disposed 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.

[0089] In this embodiment, the Z-axis motion mechanism and X-axis motion mechanism can be driven by the Y-axis motion mechanism to move along the Y direction, and the X-axis motion mechanism can be driven by the Z-axis motion mechanism to move along the Z direction. The X-axis motion mechanism ultimately drives the wafer carrier 4 to move along the X direction. Each axis motion mechanism uses a servo motor for power transmission via a ball screw. The X-axis motion mechanism uses linear guides for ease of installation, while the Z-axis and X-axis motion mechanisms, requiring compact structures, use crossed roller guides, utilizing the high rigidity of this type of guide to ensure motion accuracy. The Z-axis and X-axis motion mechanisms are machined to ensure the perpendicularity of the mounting reference, thus guaranteeing accurate positioning. Constant force springs are added to each motion axis motion mechanism to eliminate the backlash of the lead screw due to long-term use, ensuring the long-term accuracy and reliability of the equipment.

[0090] Furthermore, the wafer grinding apparatus 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 mounted 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. The cooling mechanism on the grinding wheel spindle 9 further reduces heat transfer, ensuring the reliability of wafer processing. The cooling mechanism can be water-cooled or other cooling methods, as long as they meet the requirements.

[0091] like Figure 3 As shown, the specific processing workflow in this embodiment is as follows:

[0092] S1, Start;

[0093] S2, Distance detection sensor 8 detects the height of the wafer;

[0094] S3, check whether the wafer and the grinding groove are at the same height; if not, adjust the wafer height along the Z direction of the wafer stage 6 to the same height position and then perform CCD position detection sensor 2 to scan the target image; if yes, then directly perform CCD position detection sensor 2 to scan the target image.

[0095] S4, check whether the wafer and the center of the wafer stage 6 are concentric; if not, calculate the distance the wafer needs to move in the Y direction and the error between the actual grinding point and the preset grinding point of the grinding groove, and obtain the compensation amount; if yes, calculate the error between the actual grinding point and the preset grinding point of the grinding groove and obtain the compensation amount.

[0096] S5, Generate the wafer feed path and the position of the wafer on the CCD position detection sensor 2 based on the compensation amount;

[0097] S6, the wafer is fed according to the wafer feed path;

[0098] S7, 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 triggered and grinding is terminated; if there is no deviation, normal feeding occurs.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions 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, The compensation calibration method, applied to a wafer chamfering processing apparatus, includes: Acquire a target image; wherein the target image includes: a wafer stage (6) and a wafer disposed on the wafer stage (6); The eccentricity between the center of the wafer stage (6) and the center of the wafer is determined based on the target image; The second distance from the target processing point to the center of the wafer stage (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 stage (6) and the reference line; the reference line is the line connecting the center of the wafer stage (6) and the grinding point of the grinding wheel 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 and the preset grinding point in the grinding groove; The compensation amount during grinding of the target machining point is determined based on the first distance, the second distance, and the error amount; The step of determining the second distance from the target processing point to the center of the wafer stage (6) 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: Where 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. The step of determining the compensation amount during grinding of the target machining point based on the first distance, the second distance, and the error amount includes: The wafer feed direction is determined based on the relationship between the fifth distance and the second distance; wherein, if the fifth distance is greater than the second distance, the wafer feed direction is determined to be closer to the grinding groove; if the fifth distance is less than the second distance, the wafer feed direction is determined to be farther 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|; Where a is the compensation amount; a1 is the error amount.

2. The compensation and calibration method for wafer chamfering according to claim 1, characterized in that, The step of determining the eccentricity between the center of the wafer stage (6) and the center of the wafer based on the target image includes: The coordinates of the wafer center in a preset reference coordinate system are determined 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 coordinates of the wafer center to the origin is defined as the eccentricity.

3. The compensation and calibration method for wafer chamfering according to claim 2, characterized in that, The wafer's processing edge includes a straight edge; the method further includes: The coordinates of the midpoint of the straight edge are determined based on the coordinates of the wafer center and the coordinates of any two points on the straight edge in the reference coordinate system. The distance from the coordinates of the midpoint of the straight edge to the center of the wafer stage (6) is determined as the third distance; The distance from the coordinates of the midpoint of the straight edge to the center of the wafer is defined as the fourth distance; The compensation amount during grinding of the target machining point is determined based on the third distance, the fourth distance, and the error amount.

4. The compensation and calibration method for wafer chamfering according to claim 3, 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 includes: The equation of the line containing the right edge is determined as y = (y3 - y2) / (x3 - x2) × (x - x2) + y2; where (x2, y2) are the coordinates of the first point on the right edge; and (x3, y3) are the coordinates of the second point on the right edge. The equation of the line perpendicular from the wafer center to the straight edge is determined as y = -(x3-x2) / (y3-y2)×(x-x1)+y1; where (x1, y1) are the coordinates of the wafer center. The coordinates (x4, y4) of the midpoint of the straight edge are determined based on the equation of the line containing the straight edge and the equation of the line containing the perpendicular line from the wafer center to the straight edge. The third distance is determined by the following formula: Where c is the third distance.

5. The compensation and calibration method for wafer chamfering according to claim 4, characterized in that, The step of determining the compensation amount during grinding of the target machining point based on the third distance, the fourth distance, and the error amount includes: The wafer feed direction is determined based on the relationship between the third distance and the sixth distance; wherein, 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 closer 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|; Where a is the compensation amount; a1 is the error amount; c is the third distance; and d is the fourth distance.

6. The compensation and calibration method for wafer chamfering according to claim 1, characterized in that, The step of obtaining the error between the actual grinding point and the preset grinding point of the grinding groove includes: The single error is determined based on the total grinding feed depth, the total loss of the grinding wheel (7) in the radial direction, and the cumulative feed depth before the current wafer processing. The error amount is determined by averaging the single error from multiple samplings.

7. The compensation and calibration method for wafer chamfering according to claim 1, characterized in that, Prior to the step of acquiring the target image, the compensation calibration method further includes: Obtain the height of the wafer on the wafer stage (6); The Z-axis motion of the wafer stage (6) is determined based on the height of the wafer and the height of the grinding groove.

8. A wafer chamfering processing apparatus, characterized in that, The wafer chamfering processing device is capable of implementing the compensation and calibration method for wafer chamfering processing according to any one of claims 1-7. The wafer chamfering processing device includes: a feed device (1), a CCD position detection sensor (2), a wafer grinding cavity (3), a wafer carrier 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 disposed in the wafer grinding cavity (3), the wafer carrier device (4) is disposed on the feeding device (1), the wafer carrier device (4) includes a rotatable wafer stage (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 carrier 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 the target image. The control module controls the feed device (1) to drive the wafer carrier 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 compensate and calibrate the compensation amount during the grinding of the wafer.

Images