Wafer bevel detection method and computer device

Abstract

The application discloses a wafer chamfer detection method and computer equipment, and relates to the technical field of LED, which comprises the following steps: acquiring the reference position of each wafer in a wafer box; driving a handling hand to send the wafer to a first vacuum adsorption table of a center positioning mechanism to position the wafer; driving the handling hand to send the wafer to a second vacuum adsorption table of an edge face width measuring mechanism; driving the second vacuum adsorption table to rotate to acquire image information of the sidewall of the wafer in the rotating process, and calculating the face width of the flat edge position and the circumferential position of the wafer according to the image information; driving the handling hand to send the wafer to a third vacuum adsorption table of a diameter measuring mechanism; driving the third vacuum adsorption table to rotate to measure the distance between the flat edge position and the center of the wafer, the maximum diameter and the minimum diameter; and driving the handling hand to move the wafer to the corresponding reference position of the wafer. The application can effectively improve the measurement speed and the measurement accuracy.

Description

Technical Field

[0001] This invention relates to the field of LED technology, and in particular to a method for detecting the chamfering of wafers and a computer device. Background Technology

[0002] Currently, sapphire substrates are the main material for LED chips. Because sapphire is brittle and the sharp edges generated during processing can cause stress concentration, it can lead to problems such as wafer breakage, epitaxial layer defects, and uneven photoresist coating in subsequent processes, thus directly affecting the yield and reliability of semiconductor devices. To reduce this impact, wafers need to be chamfered after cutting and grinding.

[0003] Chamfering typically involves using a metal-bonded diamond grinding wheel to grind the wafer edge at high speed. The relative movement between the grinding wheel, which has arc or trapezoidal grooves on its edge, and the wafer transforms the right-angled sidewalls into arc or trapezoidal structures. This process requires high-precision CNC chamfering equipment.

[0004] The mainstream CNC chamfering equipment includes Tokyo Seimitsu, NTS, and Qingdao Gaocheng. However, none of these manufacturers have fully automated inspection devices after chamfering; all require manual inspection. This involves using a handheld microscope to check the front and back edges, and calipers to measure the wafer diameter to confirm the chamfered quality meets requirements. Parameters are adjusted based on the measurements to gradually correct for the desired dimensional accuracy. However, this approach suffers from several drawbacks. The calipers touching the wafer circumference can easily cause edge chipping and breakage. It also requires significant manpower and is inefficient. Furthermore, variations in measurement techniques and understanding of processing principles and parameter settings can lead to inaccuracies, preventing timely optimization of parameters and resulting in significant errors in the surface area and diameter of the chamfered wafer. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a wafer chamfer detection method and computer equipment, which can effectively improve the measurement speed and measurement accuracy.

[0006] To address the aforementioned technical problems, this invention provides a wafer chamfer detection method, comprising: acquiring the reference position of each wafer in a wafer cassette; driving a transporter to deliver the wafer to a first vacuum adsorption stage of a center positioning mechanism for center positioning based on the reference position; driving the transporter to deliver the wafer to a second vacuum adsorption stage of an edge area measurement mechanism; driving the second vacuum adsorption stage to rotate to acquire image information of the wafer sidewall during rotation, and calculating the area width of the wafer at its flat edge position and circumferential position based on the image information; driving the transporter to deliver the wafer to a third vacuum adsorption stage of a diameter measurement mechanism; driving the third vacuum adsorption stage to rotate to measure the distance between the flat edge position and the center of the wafer, the maximum diameter, and the minimum diameter; and driving the transporter to move the wafer to the corresponding reference position.

[0007] As an improvement to the above solution, the step of obtaining the reference position of each wafer in the wafer cassette includes: driving the loading and unloading mechanism to move the wafer cassette back and forth in a specific direction; during the movement of the wafer cassette, driving a scanning sensor to scan the wafer cassette to collect the reference position of each wafer in the wafer cassette.

[0008] As an improvement to the above solution, the step of centering the wafer includes: driving the first positioning plate and the second positioning plate of the center positioning mechanism to move simultaneously toward the center of the first vacuum adsorption stage, so as to push the center of the wafer toward the center of the first vacuum adsorption stage, wherein the first positioning plate and the second positioning plate are arranged facing each other on both sides of the first vacuum adsorption stage; when the first positioning plate and the second positioning plate simultaneously contact the circumference of the wafer, driving the first positioning plate and the second positioning plate to stop moving; driving the first vacuum adsorption stage to turn on the vacuum to adsorb the wafer; driving the first positioning plate and the second positioning plate to move simultaneously toward the center of the first vacuum adsorption stage in the opposite direction.

[0009] As an improvement to the above solution, the step of driving the second vacuum adsorption stage to rotate to obtain image information of the wafer sidewall during rotation, and calculating the width of the wafer at the flat edge position and the circumferential position based on the image information, includes: driving the second vacuum adsorption stage to rotate, during which light emitted from the sensor emitter passes through the sidewall of the wafer and enters the sensor receiver; identifying the flat edge position of the wafer based on the light signal received by the sensor receiver; when the light signal at the flat edge position is identified, driving the second vacuum adsorption stage to rotate by a first angle and then stopping, and driving the image acquisition device to acquire image information of the light spot with wafer sidewall characteristics, and calculating the width of the flat edge position based on the image information; driving the second vacuum adsorption stage to rotate by a second angle and then stopping, and driving the image acquisition device to acquire image information of the light spot with wafer sidewall characteristics, and calculating the width of the circumferential position based on the image information.

[0010] As an improvement to the above solution, when the sidewall of the wafer adopts a trapezoidal chamfer, the step of calculating the width of the surface area includes: taking points on the upper plane of the wafer to form a first straight line, taking points on the lower plane of the wafer to form a second straight line, taking points on the upper inclined surface of the wafer to form a third straight line, taking points on the lower inclined surface of the wafer to form a fourth straight line, and taking points on the end face of the wafer to form a fifth straight line; extracting the first intersection point between the first and third straight lines, the second intersection point between the second and fourth straight lines, the third intersection point between the third and fifth straight lines, and the fourth intersection point between the fourth and fifth straight lines; calculating the vertical distance between the first and third intersection points as the upper surface area width; and calculating the vertical distance between the second and fourth intersection points as the lower surface area width.

[0011] As an improvement to the above solution, when the sidewall of the wafer adopts a rounded chamfer, the step of calculating the width of the surface area includes: taking points on the upper plane of the wafer to form a first straight line, taking points on the lower plane of the wafer to form a second straight line, and taking points on the semi-circular surface area of ​​the wafer to form an arc; extracting the first intersection point between the first straight line and the arc, the second intersection point between the second straight line and the arc, and the midpoint of the arc; calculating the vertical distance between the first intersection point and the midpoint as the upper surface area width; and calculating the vertical distance between the second intersection point and the midpoint as the lower surface area width.

[0012] As an improvement to the above solution, the wafer chamfering detection method further includes adjusting the grinding wheel position according to the surface width. Specific steps include: when the difference between the upper and lower surface widths of the wafer is greater than a preset error, if the upper surface width is greater than the lower surface width, the grinding position of the grinding wheel is moved downwards; if the lower surface width is greater than the upper surface width, the grinding position of the grinding wheel is moved upwards; when the surface width at the circumferential position of the wafer is less than a preset minimum circumferential width, the vertical feed direction of the grinding wheel is adjusted along the wafer direction; when the surface width at the circumferential position of the wafer is greater than a preset maximum circumferential width, the vertical feed direction of the grinding wheel is adjusted in the opposite direction of the wafer; when the surface width at the flat edge position of the wafer is less than a preset minimum flat edge width, the vertical feed direction of the grinding wheel is adjusted along the wafer direction; when the surface width at the flat edge position of the wafer is greater than a preset maximum flat edge width, the vertical feed direction of the grinding wheel is adjusted in the opposite direction of the wafer.

[0013] As an improvement to the above solution, the step of driving the third vacuum adsorption stage to rotate to measure the distance between the flat edge position and the center of the wafer, the maximum diameter, and the minimum diameter includes: taking points on the edge of the wafer according to at least six preset sampling frames, wherein the sampling frames have the same reference center, one sampling frame is located at the flat edge position, and the other sampling frames are located at the circumference position, the sampling frames are combined in pairs to form sampling frame groups, and the two sampling frames in the same sampling frame group are located on the same diameter corresponding to the reference center, and two reference points are taken in each sampling frame; driving the third vacuum adsorption stage to rotate, during the rotation, the reference points in each sampling frame group fall simultaneously. Within the measurement range of the diameter measuring mechanism, the measurement range includes two measurement areas located on the same diameter corresponding to the center of the reference circle; the diameter measuring mechanism is driven to measure the distance between the two sampling frames within the measurement range, and the maximum measured distance is taken as the maximum diameter, and the minimum measured distance is taken as the minimum diameter; a virtual circle is constructed based on the reference point located on the circumference; when all reference points in the sampling frame group to which the sampling frame located on the flat edge is located are within the measurement range, the center point between the reference points on the flat edge is extracted, and the distance between the center point and the virtual circle is calculated as the distance between the flat edge and the center of the circle.

[0014] As an improvement to the above solution, the wafer chamfer detection method further includes: adjusting the grinding wheel position according to the distance between the flat edge position and the center, the maximum diameter, and the minimum diameter. Specific steps include: when the distance between the flat edge position and the center is less than a preset minimum distance, reducing the feed rate of the grinding wheel during grinding; when the distance between the flat edge position and the center is greater than a preset maximum distance, increasing the feed rate of the grinding wheel during grinding; when the minimum diameter is less than a preset minimum threshold, reducing the θ-axis feed coordinate value of the grinding wheel; and when the maximum diameter is greater than a preset maximum threshold, increasing the θ-axis feed coordinate value of the grinding wheel.

[0015] Accordingly, the present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described wafer chamfer detection method.

[0016] Implementing this invention has the following beneficial effects:

[0017] The wafer chamfering inspection method of this invention only requires manual loading and unloading operations. The remaining steps, such as wafer centering, surface area inspection, and diameter measurement, are all completed by a parallel inspection mechanism and a handling operator. The measurement speed is fast, with a single wafer inspection cycle of ≤15 seconds, which is 500% more efficient than manual methods.

[0018] Meanwhile, the wafer chamfer detection method of the present invention can more accurately match the action rhythm of each mechanism, with high measurement efficiency and accuracy, small accuracy error, and better accuracy, repeatability and reliability compared with manual measurement.

[0019] Furthermore, the wafer chamfering detection method of the present invention can be linked with chamfering equipment to achieve full automation of processing and inspection, and can automatically adjust the equipment processing parameters according to the detection data to make the processing accuracy more accurate, forming a processing-inspection closed-loop control and improving the CPK value. Attached Figure Description

[0020] Figure 1 This is a flowchart of the first embodiment of the wafer chamfering detection method of the present invention;

[0021] Figure 2 This is a schematic diagram of the layout of the loading and unloading mechanism, center positioning mechanism, edge measurement mechanism, diameter measurement mechanism and conveying mechanism in the wafer chamfer detection method of the present invention;

[0022] Figure 3 This is a schematic diagram of the loading and unloading mechanism in the wafer chamfering detection method of the present invention;

[0023] Figure 4 This is a schematic diagram of the transport mechanism in the wafer chamfering detection method of the present invention;

[0024] Figure 5 This is a schematic diagram of the center positioning mechanism in the wafer chamfer detection method of the present invention;

[0025] Figure 6 This is a schematic diagram of the edge measurement mechanism in the wafer chamfer detection method of the present invention;

[0026] Figure 7 This is a schematic diagram of the sampling points when the sidewall of the wafer adopts a trapezoidal chamfer in this invention;

[0027] Figure 8 This is a schematic diagram of the sampling points when the sidewall of the wafer adopts a rounded chamfer in this invention;

[0028] Figure 9 This is a schematic diagram of the diameter measuring mechanism in the wafer chamfer detection method of the present invention;

[0029] Figure 10 This is a schematic diagram of the points used to measure the distance between the flat edge of the wafer and the center, the maximum diameter, and the minimum diameter in this invention.

[0030] Figure 11 This is a flowchart of the second embodiment of the wafer chamfer detection method of the present invention;

[0031] Figure 12 This is a schematic diagram of the adjustment distance of the grinding position in the wafer chamfer detection method of the present invention;

[0032] Figure 13 This is a schematic diagram of the vertical feed direction of the grinding wheel in the wafer chamfering detection method of the present invention;

[0033] Figure 14 This is a flowchart of the third embodiment of the wafer chamfer detection method of the present invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. It is hereby declared that the directional terms such as up, down, left, right, front, back, inside, and outside used in this text are based solely on the accompanying drawings and are not intended to specifically limit the invention.

[0035] See Figure 1 , Figure 1 The flowchart of a first embodiment of the wafer chamfer detection method of the present invention is shown, which includes:

[0036] S101, Obtain the reference position of each wafer in the wafer cassette;

[0037] like Figure 2As shown, the wafer chamfering detection method of the present invention requires a loading and unloading mechanism 1, a center positioning mechanism 2, an edge measuring mechanism 3, a diameter measuring mechanism 4, and a transport mechanism 5 (i.e., a transporter). The loading and unloading mechanism 1, the center positioning mechanism 2, the edge measuring mechanism 3, and the diameter measuring mechanism 4 adopt a four-station ring layout design, and the transport mechanism 5 is located at the center of the ring to facilitate the transport / transfer of wafers.

[0038] like Figure 3 As shown, the loading and unloading mechanism 1 includes a wafer cassette 11, a scanning sensor, a horizontal moving mechanism 12, and a vertical moving mechanism 13. The wafer cassette 11 is used to hold wafers, the scanning sensor is used to scan the wafer cassette 11, the horizontal moving mechanism 12 is used to move the wafer cassette 11 horizontally to adjust its position, and the vertical moving mechanism 13 is used to move the wafer cassette 11 vertically to adjust the height of the wafers. Accordingly, the horizontal moving mechanism 12 and the vertical moving mechanism 13 can be implemented using methods such as "guide rail + slider" or "ball screw + bearing + motor". Their specific structures are not limited here, as long as they can achieve the corresponding functions.

[0039] In this embodiment, wafer cassette A and wafer cassette B are provided. Wafer cassette A is loaded with wafers a1 to a25 from top to bottom. The scanning sensor is located on the handling arm. When it is necessary to switch wafer cassette A and wafer cassette B, the horizontal moving mechanism 12 can be driven to move wafer cassette A and wafer cassette B left and right to complete the switching of the two wafer cassette positions. When it is necessary to scan wafers a1 to a25, the vertical moving mechanism 13 can be driven to move wafer cassette A up and down while the scanning sensor is stationary. Each time the wafer cassette rises or falls by the distance of one wafer, the scanning of one wafer can be completed.

[0040] like Figure 4 As shown, the handling mechanism 5 (i.e., the handling arm / robotic arm) can be a 4-axis horizontal multi-joint cleanroom robotic arm, but this is not a limitation, as long as it can handle the wafers. In this embodiment, the handling mechanism includes two arms, one above the other; when in the same position, the upper arm can remove the wafer, then rise upwards, push forward, and place the wafer in the corresponding position on the lower arm. Then the lower arm descends downwards and retracts backwards, thus avoiding the problem of slow speed with a single arm.

[0041] Accordingly, the steps for obtaining the reference position of each wafer in the wafer cassette include:

[0042] (1) Drive the loading and unloading mechanism so that the sheet box on the loading and unloading mechanism moves back and forth in a specific direction;

[0043] (2) During the movement of the wafer cassette, the drive scanning sensor scans the wafer cassette to collect the reference position of each wafer in the wafer cassette.

[0044] During operation, the wafer cassette 11 is first moved to its initial position by the horizontal moving mechanism 12 and the vertical moving mechanism 13. Then, the wafer cassette 11 is driven to move up and down by the vertical moving mechanism 13. The scanning sensor scans from top to bottom to confirm whether there are wafers in each position of the wafer cassette 11 and records them in the computer device. The computer device will drive the transporter to pick up wafers one by one in the order from bottom to top to perform subsequent inspection steps.

[0045] S102, based on the reference position, drive the transporter to send the wafer to the first vacuum adsorption stage of the center positioning mechanism to center the wafer;

[0046] Specifically, based on the reference position, the drive arm moves to below the wafer and lifts it up to remove the wafer, which is then sent to the first vacuum adsorption stage of the center positioning mechanism for center positioning.

[0047] During operation, the transporter first moves to the bottom of the wafer in the wafer cassette, then lifts it up and removes a wafer, loading it onto the first vacuum adsorption stage of the central positioning mechanism. The transporter then retracts. Subsequently, with the vacuum not activated, the central positioning mechanism is driven to perform center positioning. After positioning is completed, the vacuum is activated to adsorb the wafer.

[0048] like Figure 5 As shown, the center positioning mechanism 2 includes a first vacuum adsorption stage 21, a first positioning plate 22, a second positioning plate 23, and a positioning drive mechanism 24. The first vacuum adsorption stage 21 uses a solenoid valve to open and close the vacuum to adsorb the wafer. The first positioning plate 22 and the second positioning plate 23 are positioned facing each other on both sides of the first vacuum adsorption stage 21. The positioning drive mechanism 24 drives the first positioning plate 22 and the second positioning plate 23 to move back and forth towards the center of the first vacuum adsorption stage 21. It should be noted that the inner sides of the first positioning plate 22 and the second positioning plate 23 are both arc-shaped structures to match the sidewalls of the wafer. The positioning drive mechanism 24 can be implemented using methods such as "guide rail + slider" or "thread + bearing + motor," and its specific structure is not limited here, as long as it can achieve the corresponding function.

[0049] Accordingly, the steps for centering the wafer include:

[0050] (1) The first positioning plate and the second positioning plate of the drive center positioning mechanism move simultaneously toward the center of the first vacuum adsorption stage, so as to push the center of the wafer to move toward the center of the first vacuum adsorption stage.

[0051] (2) When the first positioning plate and the second positioning plate simultaneously come into contact with the circumference of the wafer, drive the first positioning plate and the second positioning plate to stop moving;

[0052] (3) Drive the first vacuum adsorption stage to turn on the vacuum to adsorb the wafer;

[0053] (4) Drive the first positioning plate and the second positioning plate to move in the opposite direction to the center of the first vacuum adsorption stage.

[0054] When the wafer is placed on the first vacuum adsorption stage 21, the vacuum is initially closed. At this time, the first positioning plate 22 and the second positioning plate 23 simultaneously move towards or separate from the center of the first vacuum adsorption stage 21. The inner sides of the first positioning plate 22 and the second positioning plate 23 move precisely towards the center, pushing the center of the wafer towards the center of the vacuum adsorption stage 21. When the inner sides of the first positioning plate 22 and the second positioning plate 23 contact the circumference of the wafer, they stop rotating. Then, the vacuum adsorbs the wafer, and the first positioning plate 22 and the second positioning plate 23 separate forward and backward, thus completing the positioning action of the wafer center. When the transporter reaches under the wafer, the vacuum is closed, the wafer is no longer adsorbed, and the transporter transports the wafer to the next workstation.

[0055] It should be noted that by precisely aligning the geometric or optical center of the wafer, misjudgments caused by positional deviations can be reduced.

[0056] S103, drive the transporter to deliver the wafer to the second vacuum adsorption stage of the edge area measurement mechanism;

[0057] Specifically, the drive handle moves to below the wafer and lifts it up to remove the wafer, which is then sent to the second vacuum adsorption stage of the edge area measurement mechanism; wherein, when the handle moves to below the centered wafer, the vacuum is turned off, the handle lifts up and removes the wafer, which is then sent to the second vacuum adsorption stage of the edge area measurement mechanism, and the handle retracts.

[0058] like Figure 6 As shown, the edge measurement mechanism 3 includes a second vacuum adsorption stage 31, a sensor, an image acquisition device, a fixing plate 32, and a measurement drive mechanism 33. Specifically:

[0059] The sensor can be a Keyence (model LS-9030M) sensor, used to determine the position of the flat edge of the wafer and assist the second vacuum adsorption stage in rotating the wafer to the corresponding measurement and viewing position; wherein, the sensor includes a sensor transmitter 34 and a sensor receiver 35 arranged facing each other, the sensor transmitter 34 is located above the circumference of the side of the wafer, and the sensor receiver 35 is located below the circumference of the side of the wafer.

[0060] The image acquisition device is mounted on the fixed plate 32 and includes a telecentric lens 36, a light source emitting end 37, and a light source receiving end 38. The telecentric lens 36 is located in front of the light source emitting end 37. The light source emitting end 37, the telecentric lens 36, and the light source receiving end 38 are arranged in a straight line. The spatial position of the wafer surface shape is located between the telecentric lens 36 and the light source receiving end 38. The telecentric lens 36 measures the dimensions of the wafer circumferential edge shape in a non-contact manner.

[0061] The measurement principle of this invention is based on optical triangulation. Green LED light is emitted by the light source emitter 37 and the reflected light is received by the light source receiver 38 to achieve high-precision measurement. When used with a telecentric lens 36, the measurement accuracy and stability can be further improved. The measurement area accuracy is ±0.3µm, covering a range of ø6mm, and is suitable for rapid measurement of complex-shaped workpieces.

[0062] The measurement drive mechanism 33 is used to adjust the position of the fixed plate 32 to drive the sensor and image acquisition equipment to move, thereby moving the flat edge or circumferential position of the wafer to the projection measurement range according to the size of the wafer diameter. The measurement drive mechanism 33 can be implemented by means of "guide rail + slider" or "ball screw + motor", and its specific structure is not limited here, as long as it can achieve the corresponding function.

[0063] S104, drive the second vacuum adsorption stage to rotate to obtain image information of the wafer sidewall during rotation, and calculate the width of the wafer at the flat edge position and the circumferential position based on the image information.

[0064] Accordingly, the steps of driving the second vacuum adsorption stage to rotate to obtain image information of the wafer sidewalls during rotation, and calculating the width of the wafer at the flat edge position and the circumferential position based on the image information include:

[0065] (1) Drive the second vacuum adsorption stage to rotate. During the rotation, the light emitted from the sensor transmitter passes through the sidewall of the wafer and enters the sensor receiver.

[0066] (2) Identify the flat edge position of the wafer based on the optical signal received by the sensor receiver;

[0067] (3) When the light signal at the flat edge position is detected, the second vacuum adsorption stage 31 is driven to rotate by the first angle and then stopped, and the image acquisition device is driven to acquire the image information of the light spot with the wafer sidewall feature. The width of the flat edge position is calculated based on the image information.

[0068] (4) Drive the second vacuum adsorption stage 31 to rotate by a second angle and then stop and drive the image acquisition device to acquire image information of the light spot with wafer sidewall features, and calculate the area width of the circumferential position based on the image information.

[0069] It should be noted that the values ​​of the first and second angles can be set according to the relationship between the position of the flat edge and the sensing area of ​​the sensor (e.g., the flat edge entering the sensing area and the flat edge exiting the sensing area), and the positional relationship between the sensing area of ​​the sensor and the detection area of ​​the image acquisition device. Specifically, after the second vacuum adsorption stage 31 rotates by the first angle, it must ensure that the flat edge is rotated to the detection area of ​​the image acquisition device and that the flat edge is parallel to the green LED light emitted by the light source emitting end 37; after the second vacuum adsorption stage 31 rotates by the second angle, it must ensure that the non-flat edge (i.e., the circumferential position) is rotated to the detection area of ​​the image acquisition device.

[0070] When the wafer is placed on the second vacuum adsorption stage 31, the second vacuum adsorption stage 31 drives the wafer to rotate. At this time, the sensor emitter 34 emits parallel light, which passes through the edge of the wafer and reaches the sensor receiver 35 below. During the rotation, when the flat edge passes through the sensor's sensing area (i.e., the flat edge just enters the flat edge sensing area and the flat edge just leaves the sensing area), the sensor receiver 35 will sense the change in the light signal, thereby calculating the flat edge position, and controlling the second vacuum adsorption stage 31 to rotate by a first angle and then stop to move the flat edge of the wafer to the detection area of ​​the image acquisition device, and ensuring that the flat edge is parallel to the green LED light emitted by the light source emitter 37 to form a light spot with wafer sidewall characteristics. Then, the surface shape of the flat edge position is calculated based on the image information of the light spot. Then, the second vacuum adsorption stage 31 is controlled to rotate by a second angle and then stop to move the circumferential position of the wafer to the detection area of ​​the image acquisition device to form a light spot with wafer sidewall characteristics. Then, the surface shape of the circumferential position is calculated based on the image information of the light spot.

[0071] Therefore, the present invention can control the fixed plate 32 to move back and forth by rotating the wafer multiple times and stopping it, and measure the surface area of ​​the wafer at the flat edge position and the surface area of ​​the circumference position respectively.

[0072] like Figure 7 As shown, when the sidewalls of a wafer have trapezoidal chamfers, the steps for calculating the surface width include:

[0073] K1, take points on the upper plane of the wafer to form a first straight line, take points on the lower plane of the wafer to form a second straight line, take points on the upper inclined surface of the wafer to form a third straight line, take points on the lower inclined surface of the wafer to form a fourth straight line, and take points on the end face of the wafer to form a fifth straight line.

[0074] For example, points can be automatically selected according to preset selection frame locations:

[0075] Points f1 and f2 are taken on the plane of the wafer, and the two points form the first straight line A1.

[0076] Points f3 and f4 are taken on the lower plane of the wafer, and the two points form the second straight line B1;

[0077] Points f5 and f6 are taken on the inclined plane of the wafer, and the two points form a third straight line C1;

[0078] Points f7 and f8 are taken on the inclined plane of the wafer, and the two points form the fourth straight line D1;

[0079] Points f9 and f10 are taken from the end face of the wafer, and the two points form the fifth straight line E1.

[0080] K2, extract the first intersection point between the first and third lines, the second intersection point between the second and fourth lines, the third intersection point between the third and fifth lines, and the fourth intersection point between the fourth and fifth lines;

[0081] For example, the intersection point formed by taking points can be used as the base point for dimension calculation:

[0082] The point where the first line A1 intersects the third line C1 (i.e., the first intersection point) is U1;

[0083] The point where the second line B1 intersects the fourth line D1 (i.e., the second intersection point) is V1;

[0084] The point where the third line C1 intersects the fifth line E1 (i.e., the third intersection point) is W1;

[0085] The point where the fourth line D1 intersects the fifth line E1 (i.e., the fourth intersection point) is N1.

[0086] K3, calculate the vertical distance between the first intersection point and the third intersection point to use as the width of the upper section;

[0087] For example, the vertical distance between the first intersection point U1 and the third intersection point W1 is the width H1 of the upper section.

[0088] K4, calculate the vertical distance between the second and fourth intersection points to be used as the width of the lower section.

[0089] For example, the vertical distance between the second intersection point V1 and the fourth intersection point N1 is the width H2 below.

[0090] It should be noted that the number of measurement points can be set in the program according to the actual situation to meet the needs of multi-point measurement.

[0091] like Figure 8 As shown, when the sidewalls of a wafer are rounded, the steps for calculating the surface width include:

[0092] K1, take points on the upper plane of the wafer to form a first straight line, take points on the lower plane of the wafer to form a second straight line, and take points on the semi-circular surface of the wafer to form an arc.

[0093] For example, automatically select points according to the preset selection frame locations:

[0094] Points g1 and g2 are taken on the plane of the wafer, and the two points form the first straight line A2.

[0095] Points g3 and g4 are taken on the lower plane of the wafer, and the two points form the second straight line B2.

[0096] Four points (g5, g6, g7, and g8) are evenly selected on the semi-circular surface to form an arc.

[0097] K2, extract the first intersection point between the first straight line and the arc, the second intersection point between the second straight line and the arc, and the midpoint of the arc;

[0098] For example, the intersection point formed by taking points can be used as the base point for dimension calculation:

[0099] The intersection point (i.e., the first intersection point) of the first straight line A2 and the arc is U2;

[0100] The intersection point (i.e., the second intersection point) of the second straight line B2 and the arc is V2;

[0101] The leftmost quadrant point of the arc (i.e., the midpoint of the arc) is W2.

[0102] K3, calculate the vertical distance between the first intersection point and the midpoint to be used as the width of the upper section;

[0103] For example, the vertical distance between the first intersection point U2 and the midpoint W2 is the width H3 of the upper section.

[0104] K4, calculate the vertical distance between the second intersection point and the midpoint to be used as the width of the lower section.

[0105] For example, the vertical distance between the second intersection point V2 and the midpoint W2 is the width H4 of the lower section.

[0106] S105, drive the transporter to deliver the wafer to the third vacuum adsorption stage of the diameter measurement mechanism;

[0107] Specifically, the drive handle moves to below the wafer and lifts it up to remove the wafer, which is then sent to the third vacuum adsorption stage of the diameter measuring mechanism; wherein, after the handle moves to below the wafer whose width has been measured, the vacuum is turned off, the handle lifts up and removes the wafer, which is then sent to the third vacuum adsorption stage of the diameter measuring mechanism, and the handle retracts.

[0108] like Figure 9As shown, the diameter measuring mechanism 4 can be a Keyence TM-X5006. After the wafer has undergone circumferential chamfering, the diameter measuring mechanism 4 measures the outer diameter of the wafer in a non-contact manner. Specifically, the diameter measuring mechanism 4 includes a third vacuum adsorption stage 41 and two TM-X series sensor heads 42. By placing the wafer in the measurement area, it can rotate while measuring.

[0109] S106 drives the third vacuum adsorption stage to rotate in order to measure the distance between the flat edge position of the wafer and the center, the maximum diameter and the minimum diameter;

[0110] During operation, the wafer is positioned parallel to the left and right sides according to the flat edge position confirmed by the edge area measurement mechanism. The distance between the flat edge position and the center of the circle is measured. Then the wafer is rotated and the wafer diameter is measured to obtain the maximum and minimum values.

[0111] Accordingly, the steps of driving the third vacuum adsorption stage to rotate to measure the distance between the flat edge position and the center of the wafer, the maximum diameter, and the minimum diameter include:

[0112] (1) Take points on the edge of the wafer according to at least six preset point frames;

[0113] It should be noted that the point frames have the same reference center. One point frame is set at the flat edge position, and the other point frames are set at the circumference position. The point frames are combined in pairs to form a point frame group, and the two point frames in the same point frame group are set on the same diameter corresponding to the reference center. Each point frame takes two reference points.

[0114] like Figure 10 As shown, in this embodiment, eight point selection frames are preset, and each point selection frame selects two points as reference points for a straight line (flat edge position) or an arc (circumferential position), and the dimensions between the reference points are calculated.

[0115] (2) Drive the third vacuum adsorption stage to rotate. During the rotation, the reference points in each sampling frame group fall into the measurement range of the diameter measuring mechanism at the same time.

[0116] The measurement range includes two measurement areas located on the same diameter corresponding to the center of the reference circle;

[0117] (3) Drive the diameter measuring mechanism to measure the distance between two sampling frames within the measurement range respectively, take the maximum measured distance as the maximum diameter, and take the minimum measured distance as the minimum diameter;

[0118] For example, rotating the third vacuum adsorption stage 41 so that the sampling frames k1-1 and k1-2 are respectively within the measurement range directly below the two measuring heads, the distance between the arc quadrant points formed by them is the diameter dimension D1; rotating the third vacuum adsorption stage so that the sampling frames k2-1 and k2-2 are respectively within the measurement range directly below the two measuring heads, the distance between the arc quadrant points formed by them is the diameter dimension D2; rotating the third vacuum adsorption stage so that the sampling frames k3-1 and k3-2 are respectively within the measurement range directly below the two measuring heads, the distance between the arc quadrant points formed by them is the diameter dimension D3.

[0119] (4) Construct a virtual circle based on the reference point set on the circumference;

[0120] For example, virtual circle X can be formed by taking point boxes k1-1 and k1-2, k2-1 and k2-2, k3-1 and k3-2, and adding point box k5.

[0121] (5) When all reference points in the reference point group of the reference point set on the flat edge are within the measurement range, extract the center point between the reference points on the flat edge and calculate the distance between the center point and the virtual circle as the distance between the flat edge and the center of the circle.

[0122] For example, rotating the third vacuum adsorption stage so that the sampling frames k4 and k5 are within the measurement range directly below the two measuring heads. The center point between the two reference points of the sampling frame k4 is Y. The straight-line distance from the virtual circle X to the center point Y is the distance Z between the flat edge position and the center of the circle. The size of Z determines whether the flat edge size of the wafer meets the requirements.

[0123] S107, drive the transporter to move the wafer to the reference position corresponding to the wafer.

[0124] After all measurements are completed, the transporter moves the wafer to its original position (i.e., the reference position) in the original wafer cassette, returning it to its original position to complete the inspection.

[0125] Furthermore, the inspection results of each wafer can be automatically uploaded to the production execution system to generate an inspection report that includes a 3D topography image, dimensional tolerance zone, and historical trend analysis.

[0126] In summary, the wafer chamfering inspection method of this invention only requires manual loading and unloading operations. The remaining steps, such as wafer centering, surface area inspection, and diameter measurement, are all completed by a parallel inspection mechanism and a handling operator. The measurement speed is fast, with a single wafer inspection cycle of ≤15 seconds, which is 500% more efficient than manual methods. At the same time, this invention, combined with a precise algorithm, can more accurately match the action rhythm of each mechanism, resulting in high measurement efficiency, high accuracy, and small accuracy error. Compared with manual measurement, the accuracy, repeatability, and reliability of the measurement are better. In addition, this invention is compatible with 4-8 inch wafers after switching processing programs and position parameters, with a changeover time of less than 5 minutes.

[0127] See Figure 11 , Figure 11 A flowchart of a second embodiment of the wafer chamfer detection method of the present invention is shown, which includes:

[0128] S201, Obtain the reference position of each wafer in the wafer cassette;

[0129] S202, based on the reference position, drive the transporter to send the wafer to the first vacuum adsorption stage of the center positioning mechanism to center the wafer;

[0130] S203, drive the transporter to deliver the wafer to the second vacuum adsorption stage of the edge area measurement mechanism;

[0131] S204, drive the second vacuum adsorption stage to rotate to obtain image information of the wafer sidewall during rotation, and calculate the width of the wafer at the flat edge position and the circumferential position based on the image information.

[0132] S205, adjust the grinding wheel position according to the width of the surface area;

[0133] and Figure 1 The difference from the first embodiment is that this embodiment introduces an automatic grinding wheel position adjustment method based on the width of the surface area, the specific steps of which include:

[0134] (1) When the difference between the upper width and the lower width of the wafer is greater than the preset error, if the upper width is greater than the lower width, the grinding position of the grinding wheel is moved downward; if the lower width is greater than the upper width, the grinding position of the grinding wheel is moved upward.

[0135] like Figure 12 The formula for calculating the area adjustment is as follows:

[0136] 30° chamfer: Grinding position adjustment distance Hd = (upper width - lower width) / (2 / sin30°);

[0137] 45° chamfer: The adjustment distance Hd for the grinding position is Hd = (upper width - lower width) / (2 / tan45°).

[0138] (2) When the width of the wafer circumference is less than the preset minimum circumference width, the vertical feed direction P of the grinding wheel M1 (see Figure 13 Adjust along the M2 direction (i.e., the positive direction) of the wafer; when the width of the wafer circumference is greater than the preset maximum circumference width, adjust the vertical feed direction of the grinding wheel in the opposite direction of the wafer.

[0139] Accordingly, the adjustment distance for the grinding wheel position is (upper width - lower width) / 4.

[0140] (3) When the width of the flat edge of the wafer is less than the preset minimum flat edge width, the vertical feed direction of the grinding wheel is adjusted along the wafer direction; when the width of the flat edge of the wafer is greater than the preset maximum flat edge width, the vertical feed direction of the grinding wheel is adjusted in the opposite direction of the wafer.

[0141] Accordingly, the grinding wheel position adjustment distance = standard width - actual width.

[0142] In practical applications, parameters can be adjusted manually or automatically to improve processing accuracy. Furthermore, an adaptive compensation mechanism can be introduced to correct chamfering machine parameters (such as grinding wheel feed position and grinding wheel vertical position adjustment) in real time based on detection data.

[0143] S206, drive the transporter to deliver the wafer to the third vacuum adsorption stage of the diameter measuring mechanism;

[0144] S207 drives the third vacuum adsorption stage to rotate in order to measure the distance between the flat edge position of the wafer and the center, the maximum diameter and the minimum diameter;

[0145] S208 drives the transporter to move the wafer to the reference position corresponding to the wafer.

[0146] Therefore, the wafer chamfering inspection method of this invention can be linked with chamfering equipment, adopting integrated control and cooperating with the wafer loading and unloading mechanism of the chamfering machine to achieve full automation of processing and inspection, completely replacing manual operation. It can also automatically adjust the processing parameters of the equipment according to the inspection data, making the processing accuracy more accurate. Furthermore, an adaptive compensation mechanism can be introduced to correct the chamfering machine parameters (such as the feed position of the grinding wheel and the adjustment of the vertical position of the grinding wheel) in real time based on the inspection data, forming a processing-inspection closed-loop control and improving the CPK value.

[0147] See Figure 14 , Figure 14 The flowchart of a third embodiment of the wafer chamfer detection method of the present invention is shown, which includes:

[0148] S301, Obtain the reference position of each wafer in the wafer cassette;

[0149] S302, based on the reference position, drive the transporter to send the wafer to the first vacuum adsorption stage of the center positioning mechanism to center the wafer;

[0150] S303, drives the transporter to deliver the wafer to the second vacuum adsorption stage of the edge area measurement mechanism;

[0151] S304, drive the second vacuum adsorption stage to rotate to obtain image information of the wafer sidewall during the rotation process, and calculate the width of the wafer at the flat edge position and the circumferential position based on the image information.

[0152] S305, adjust the grinding wheel position according to the width of the surface area;

[0153] S306, drive the transporter to deliver the wafer to the third vacuum adsorption stage of the diameter measuring mechanism;

[0154] S307 drives the third vacuum adsorption stage to rotate in order to measure the distance between the flat edge position of the wafer and the center, the maximum diameter, and the minimum diameter.

[0155] S308, adjust the grinding wheel position according to the distance between the flat edge and the center of the circle, the maximum diameter, and the minimum diameter;

[0156] and Figure 11 The second embodiment shown differs in that it introduces an automatic adjustment method for the grinding wheel position based on the center distance and diameter. The specific steps include:

[0157] (1) When the distance between the flat edge position and the center of the circle is less than the preset minimum distance, the feed rate during grinding is reduced; when the distance between the flat edge position and the center of the circle is greater than the preset maximum distance, the feed rate during grinding is increased.

[0158] In other words, when the distance between the flat edge and the center is small, the feed rate of the grinding wheel should be smaller; when the distance between the flat edge and the center is large, the feed rate of the grinding wheel should be larger.

[0159] Accordingly, the adjusted distance = standard distance - actual distance.

[0160] (2) When the minimum diameter is less than the preset minimum threshold, the θ-axis feed coordinate value of the grinding wheel is reduced; when the maximum diameter is greater than the preset maximum threshold, the θ-axis feed coordinate value of the grinding wheel is increased.

[0161] In other words, if the diameter is too small, it means that the grinding wheel is fed too much, and the θ-axis feed coordinate value needs to be reduced accordingly according to the error value; conversely, if the diameter is too large, it should be increased accordingly.

[0162] Furthermore, if the difference between the measured diameters exceeds the standard value, the θ axial feed coordinate value of each chamfer angle needs to be adjusted accordingly, either increasing or decreasing it.

[0163] Similarly, in practical applications, parameters can be adjusted manually or automatically to make the processing accuracy more precise. At the same time, an adaptive compensation mechanism can be introduced to correct the chamfering machine parameters (such as the grinding wheel feed position and the grinding wheel vertical position adjustment) in real time based on the detection data.

[0164] S309, drives the transporter to move the wafer to the reference position corresponding to the wafer.

[0165] Therefore, the wafer chamfering inspection method of this invention replaces manual inspection with automation, effectively avoiding quality instability caused by human measurement errors and significantly improving inspection efficiency and accuracy. At the same time, this invention can automatically adjust the equipment processing parameters according to the inspection data, making the processing accuracy more accurate. In addition, this invention uses optical non-contact measurement components, which are accurate in measurement, do not damage the wafer, have a simple mechanism design, low equipment manufacturing cost, low equipment failure rate, stable operation, high work efficiency, and almost no consumable consumption.

[0166] Accordingly, the present invention also discloses a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described wafer chamfer detection method.

[0167] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for detecting the chamfer of a wafer, characterized in that, include: Obtain the reference position of each wafer in the wafer cassette; Based on the reference position, the drive transporter delivers the wafer to the first vacuum adsorption stage of the center positioning mechanism to center the wafer; The transporter is driven to deliver the wafer to the second vacuum adsorption stage of the edge area measurement mechanism; The second vacuum adsorption stage is driven to rotate to obtain image information of the sidewall of the wafer during the rotation process, and the surface width of the wafer at the flat edge position and the circumferential position is calculated based on the image information. The specific steps include: driving the second vacuum adsorption stage to rotate, during which light emitted from the sensor emitter passes through the sidewall of the wafer and enters the sensor receiver; identifying the flat edge position of the wafer based on the light signal received by the sensor receiver; when the light signal at the flat edge position is identified, driving the second vacuum adsorption stage to rotate by a first angle and then stopping, and driving the image acquisition device to acquire image information of the light spot with wafer sidewall characteristics, and calculating the area width of the flat edge position based on the image information; driving the second vacuum adsorption stage to rotate by a second angle and then stopping, and driving the image acquisition device to acquire image information of the light spot with wafer sidewall characteristics, and calculating the area width of the circumferential position based on the image information; The transporter is driven to deliver the wafer to the third vacuum adsorption stage of the diameter measuring mechanism; The third vacuum adsorption stage is driven to rotate to measure the distance between the flat edge of the wafer and the center, the maximum diameter, and the minimum diameter. The transporter is driven to move the wafer to the reference position corresponding to the wafer.

2. The wafer chamfering detection method as described in claim 1, characterized in that, The step of obtaining the reference position of each wafer in the wafer cassette includes: Drive the loading and unloading mechanism to make the sheet box on the loading and unloading mechanism move back and forth in a specific direction; During the movement of the wafer cassette, a driving scanning sensor scans the wafer cassette to acquire the reference position of each wafer in the wafer cassette.

3. The wafer chamfering detection method as described in claim 1, characterized in that, The steps for centering the wafer include: The first positioning plate and the second positioning plate of the drive center positioning mechanism move simultaneously toward the center of the first vacuum adsorption stage, so as to push the center of the wafer to move toward the center of the first vacuum adsorption stage. The first positioning plate and the second positioning plate are arranged facing each other on both sides of the first vacuum adsorption stage. When the first positioning plate and the second positioning plate simultaneously come into contact with the circumference of the wafer, the first positioning plate and the second positioning plate are driven to stop moving. Drive the first vacuum adsorption stage to turn on the vacuum to adsorb the wafer; The first positioning plate and the second positioning plate are driven to move in the opposite direction to the center of the first vacuum adsorption stage.

4. The wafer chamfering detection method as described in claim 1, characterized in that, When the sidewalls of the wafer are chamfered in a trapezoidal shape, the steps for calculating the width of the surface area include: Points are taken on the upper plane of the wafer to form a first straight line, points are taken on the lower plane of the wafer to form a second straight line, points are taken on the upper inclined surface of the wafer to form a third straight line, points are taken on the lower inclined surface of the wafer to form a fourth straight line, and points are taken on the end face of the wafer to form a fifth straight line. Extract the first intersection point between the first line and the third line, the second intersection point between the second line and the fourth line, the third intersection point between the third line and the fifth line, and the fourth intersection point between the fourth line and the fifth line; Calculate the vertical distance between the first intersection point and the third intersection point to use as the width of the upper section; Calculate the vertical distance between the second and fourth intersection points to determine the width of the lower section.

5. The wafer chamfering detection method as described in claim 1, characterized in that, When the sidewalls of the wafer are rounded, the step of calculating the width of the area includes: Points are taken on the upper plane of the wafer to form a first straight line, points are taken on the lower plane of the wafer to form a second straight line, and points are taken on the semi-circular surface of the wafer to form an arc. Extract the first intersection point between the first straight line and the arc, the second intersection point between the second straight line and the arc, and the midpoint of the arc; Calculate the vertical distance between the first intersection point and the midpoint to determine the width of the upper section; Calculate the vertical distance between the second intersection point and the midpoint to determine the width of the lower section.

6. The wafer chamfering detection method as described in claim 5, characterized in that, It also includes adjusting the position of the grinding wheel according to the width of the surface area, and the specific steps include: When the difference between the upper width and the lower width of the wafer is greater than a preset error, if the upper width is greater than the lower width, the grinding position of the grinding wheel is moved downward; if the lower width is greater than the upper width, the grinding position of the grinding wheel is moved upward. When the width of the wafer circumference is less than the preset minimum circumference width, the vertical feed direction of the grinding wheel is adjusted along the wafer direction. When the width of the wafer circumference is greater than the preset maximum circumference width, the vertical feed direction of the grinding wheel is adjusted in the opposite direction of the wafer. When the width of the flat edge of the wafer is less than the preset minimum flat edge width, the vertical feed direction of the grinding wheel is adjusted along the wafer direction. When the width of the flat edge of the wafer is greater than the preset maximum flat edge width, the vertical feed direction of the grinding wheel is adjusted in the opposite direction of the wafer.

7. The wafer chamfering detection method as described in claim 1, characterized in that, The step of driving the third vacuum adsorption stage to rotate to measure the distance between the flat edge position and the center of the wafer, the maximum diameter, and the minimum diameter includes: Points are taken on the edge of the wafer according to at least six preset sampling frames. The sampling frames have the same reference center. One sampling frame is located at the flat edge position, and the other sampling frames are located at the circumference position. The sampling frames are combined in pairs to form a sampling frame group. The two sampling frames in the same sampling frame group are located on the same diameter corresponding to the reference center. Each sampling frame takes two reference points. The third vacuum adsorption stage is driven to rotate. During the rotation, the reference points in each sampling frame group fall into the measurement range of the diameter measuring mechanism at the same time. The measurement range includes two measurement areas set on the same diameter corresponding to the center of the reference circle. The driving diameter measuring mechanism measures the distance between two sampling frames within the measurement range, and takes the maximum measured distance as the maximum diameter and the minimum measured distance as the minimum diameter. A virtual dot is constructed based on the reference point set at the circumference position; When all reference points in the reference frame group to which the reference frame is located at the flat edge position are within the measurement range, the center point between the reference points at the flat edge position is extracted, and the distance between the center point and the virtual circle is calculated as the distance between the flat edge position and the center of the circle.

8. The wafer chamfering detection method as described in claim 1 or 7, characterized in that, Also includes: Adjust the grinding wheel position based on the distance between the flat edge and the center of the circle, the maximum diameter, and the minimum diameter. Specific steps include: When the distance between the flat edge position and the center of the circle is less than the preset minimum distance, the feed rate during grinding is reduced. When the distance between the flat edge position and the center of the circle is greater than the preset maximum distance, the feed rate during grinding is increased. When the minimum diameter is less than the preset minimum threshold, the θ-axis feed coordinate value of the grinding wheel is reduced. When the maximum diameter is greater than the preset maximum threshold, the θ-axis feed coordinate value of the grinding wheel is increased.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the wafer chamfer detection method according to any one of claims 1 to 8.

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