Laser processing method, device for sapphire and storage medium

Abstract

Laser processing methods for a sapphire, including: Taking an image of the sapphire (18) during processing (502) characterized by Performing edge detection on the image to obtain a coordinate of a crack (5, 50) (504) Determining an offset parameter according to the coordinate of the crack (5, 50) (506); Setting a laser processing position according to the offset parameter (508), and Further processing of the sapphire (18) according to the set laser processing position (510) where determining the offset parameter includes: Taking a center coordinate of the image (1002); Calculating an average value of the coordinate of the crack (5, 50) (1004); and Taking the offset parameter according to the average value and the center coordinate (1006), where calculating the average value of the crack coordinate (5, 50) includes: Extracting the coordinates corresponding to the point on the edge of the crack (5, 50); and Calculating an average value of the coordinates according to the different coordinate axes.

Description

[0001] This application claims priority over Chinese application No. 201510239300.X entitled “LASER PROCESSING METHOD FOR SAPPHI-RE”, which was filed on May 12, 2015. AREA OF INVENTION

[0002] The present disclosure relates to the technical field of laser processing and relates in particular to a laser processing method, a device for sapphire, and a storage medium. The features of the preamble of claim 1 are known from US 7,112,518 B2. Related technologies are known from US 2002 / 0088952 A1 and US 5,727,433 A. BACKGROUND OF THE INVENTION

[0003] In laser micro-precision machining of semiconductors, such as LED wafers and the like, the sapphire substrate used is usually a wafer with a c-plane. As in Fig. As shown in Figure 1, during the laser singulation process of the LED wafer, the entire piece of the circular wafer must be divided into a plurality of individual core particles with a rectangular shape. Two mutually perpendicular singulation directions generally correspond to an a-plane and an m-plane of the sapphire crystal, and the a-plane and the m-plane are both perpendicular to the c-plane. Since the m-plane is close to the r-plane (slit plane), and the r-plane is not perpendicular to the c-plane and forms a certain angle of inclination to the c-plane, the individual final core particles are actually fractured along the r-plane after laser singulation. This results in a certain deviation between the laser processing point, which corresponds to the CCD camera (CCD for charge-coupled device), and the actual fracture position of the wafer, causing the actual fracture to deviate from the intermediate position of the singulation path.If the singulation path has a larger width, the actual crack does not extend into the emitting electrode (EEE) area of ​​the chip. However, during the manufacturing process, to maximize production, the width of the singulation path is progressively reduced. If the crack deviates from the intermediate position of the singulation path, the emitting electrode area of ​​the chip will be scratched, thus reducing the final yield. SUMMARY OF THE INVENTION

[0004] According to various embodiments, the present disclosure relates to a laser processing method, a device for sapphire, and a storage medium. The invention is defined by the independent claims.

[0005] A laser processing process for sapphire includes: Taking a picture of the sapphire during processing; Performing edge detection on the image to obtain a coordinate of a crack; Determining an offset parameter according to the coordinate of the crack; Setting a laser processing position according to the offset parameter; and further processing of the sapphire according to the set laser processing position.

[0006] A laser processing device for the sapphire is provided, comprising a processor and a memory that stores instructions which, when executed by the processor, cause the processor to perform operational sequences, including: Taking a picture of the sapphire during processing; Performing edge detection on the image to obtain a coordinate of a crack; Determining an offset parameter according to the coordinate of the crack; Setting a laser processing position according to the offset parameter; and further processing of the sapphire according to the set laser processing position.

[0007] A non-volatile, computer-readable medium stores instructions which, when executed by one or more processors, cause one or more processors to perform operational processes, including: Taking a picture of the sapphire during processing; Performing edge detection on the image to obtain a coordinate of a crack; Determining an offset parameter according to the coordinate of the crack; Setting a laser processing position according to the offset parameter; and further processing of the sapphire according to the set laser processing position.

[0008] These and other tasks, advantages, purposes and features will become apparent when considering the following description in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The components in the drawings are not necessarily to scale; the emphasis is instead on a clear illustration of the principles of this disclosure. Furthermore, in the drawings, the same reference numerals denote corresponding parts in the different views. Fig. 1 is a cell unit diagram of a sapphire according to one embodiment; Fig. Figure 2 is a top view showing a singulation direction of a sapphire wafer according to one embodiment; Fig. Figure 3 is a sectional view showing a conventional singulation process of a sapphire wafer along an intermediate position of the singulation path; Fig. Figure 4 is a schematic structural diagram of a laser processing device for a sapphire wafer according to one embodiment; Fig. Figure 5 is a flowchart of a laser processing procedure for a sapphire according to one embodiment; Fig. Figure 6 is a sectional view showing a singulation process of a sapphire wafer along the intermediate position of the singulation path according to one embodiment; Fig. Figure 7 is a sectional view showing a singulation process of a sapphire wafer after setting the processing section according to an embodiment; Fig. Figure 8 is a top view showing a relative position between a machining plane of the sapphire and the center of the image according to one embodiment; Fig. Figure 9 is a flowchart of a method for extracting the coordinate of the crack according to one embodiment; Fig. Figure 10 is a flowchart of a method for calculating an offset parameter according to one embodiment; and Fig. Figure 11 shows the position of the crack in the recorded image according to one embodiment. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0010] The above-mentioned problems, features, and advantages of the present invention will become apparent from the description of detailed embodiments thereof with reference to the accompanying drawings. Furthermore, it should be understood by those skilled in the art that they can carry out other embodiments of the disclosure without one or more of the details described above.

[0011] Fig. Figure 1 shows a cell unit diagram of a sapphire. The sapphire substrate used in the LED array is typically a wafer with a c-plane. Two mutually perpendicular singulation directions of the wafer generally correspond to an m-plane and an a-plane. Referring to Fig. 2 are the two singulation directions for the wafer, an m-axis and an a-axis, which are perpendicular to the m-plane and the a-plane, respectively. Fig. 2 is a projection of Fig. 1 in the c-plane, where the flat edge is parallel to the m-axis.

[0012] As in Fig. As can be seen in Figure 1, the m-plane is located close to the r-plane (cleavage plane). During singulation of the m-plane, the wafer tends to crack at the r-plane due to the characteristics of the sapphire crystal's r-plane. Therefore, after laser singulation, the actual crack plane is the r-plane instead of the m-plane, resulting in a certain angle of inclination between the r-plane and the c-plane in the processed sample.

[0013] Referring to Fig. In process 3, used in the industrial laser singulation of LED wafers, the laser beam is focused in the sapphire substrate such that it forms a plurality of convergent points, and the sapphire fractures using the voltage generated by these convergent points. An electrode 1 with rectangular periodic patterns is grown on the sapphire substrate, separated from each other at right angles by singulation paths 2. Since the r-plane is fractured obliquely, it is possible that the actual fracture position is not located at an intermediate position within the singulation path 2, or that the fracture may even reach the patterned region of the electrode 1, thus generating defective products and reducing the yield.

[0014] The crack direction of the r-plane is observed from the cross-section of the a-plane. The laser beam 3 is directed vertically onto the interior of the sapphire substrate to form a convergent point 4, and the incidence position of the laser beam 3 is aligned with the intermediate position O of the singulation path 2. However, due to the presence of the r-plane, the actual crack 5 is not located at the intermediate position O of the singulation path 2, resulting in a non-uniform electrode surface and impairing the processing yield. If the width of the singulation path is less than 30 µm or even smaller, there is a tendency for the crack 5 to propagate into the electrode 1, producing defective products.

[0015] Fig. Figure 4 is a schematic diagram of a laser processing system for sapphire. In the laser processing system, a device 7 serves as a control device for the processing environment, capable of controlling each component of the processing environment to implement a laser processing procedure. A laser condenser lens 17 has both a laser processing function and an imaging function. A CCD camera 14 is configured to view a surface image and the crack of a sapphire wafer 18. During the specific imaging procedure, a point light source 8 and an area light source 22 are switched on simultaneously, enabling optimal imaging results of the back side of the sapphire, and the image is easily identifiable to aid image acquisition.The CCD camera 14 is connected to the device 7, allowing a monitor of the device 7 to display the image across the entire imaging field of view of the CCD camera. A laser beam 16 passes through a beam splitter 12 and enters a condenser lens 17, focusing on the interior of the sapphire 18 to form a convergent laser spot 4. A mounting table 19 performs a uniform linear movement along one direction of the a-axis, thus processing the m-plane of the sapphire.

[0016] Referring to Fig. Figure 5 describes a laser processing method for the sapphire. In the embodiment shown, the method can be applied to the laser processing system for the sapphire, as shown in Figure 5. Fig. The device 7 can run a laser processing program for the sapphire, and the laser processing method is implemented by the laser processing program for the sapphire. The method specifically comprises the following steps: In step 502, an image of the sapphire is captured during processing. Specifically, during sapphire processing, the device 7 can capture the image of the sapphire via the CCD camera 14, which is connected to the device 7. The CCD camera 14 can transmit the image of the sapphire in its field of view to the device 7, and the device 7 can then display the image in the field of view of the CCD camera 14 on the monitor. The image can be a partial image that is magnified by a certain factor by the CCD camera during laser processing, so that the crack created during sapphire processing can be viewed in the magnified partial image.

[0017] In one embodiment, step 502 comprises: machining the sapphire along an intermediate point of a singulation path, thereby forming the crack in the sapphire; and taking the image of the sapphire with the crack.

[0018] In particular, with reference to Fig. 6. At the m-plane, the processing is carried out by positioning the laser beam, which is to be aligned with the intermediate position O of a singulation path 20. The laser beam 30 shines vertically into the sapphire substrate at the intermediate position O of a singulation path 20, and the convergent point 40 is formed in the sapphire. An actual crack 50 is created, but it is not located at the intermediate position O of the singulation path 20. The device 7 can capture the image of the sapphire with the crack 50 via the CCD camera, and the image of the sapphire with the crack 50 can be displayed so that the crack 50 of the sapphire can be viewed from the image of the sapphire. By reducing the width of the singulation path 20, the yield of the single chip produced from the same wafer can be increased.The sapphire comprises a front and a back with an electrode 10, the interlocking singulation path 20 is formed on the back, and the electrode 10 is separated by the singulation path 20.

[0019] In one embodiment, taking the image of the sapphire with the crack comprises: directing a light source and rays of light generated by the light source onto the sapphire with the crack; and taking the image of the sapphire illuminated by the light.

[0020] In one embodiment, capturing the image of the sapphire illuminated by the light comprises: transmitting an image capture instruction to a CCD camera, and capturing the image of the sapphire illuminated by the light by the CCD camera in a field of view according to the image capture instruction.

[0021] In particular, with reference to Fig. 4. The device 7 controls the point light source 8 and the area light source 22. Light emitted from the point light source 8 passes through a convex lens 9, a 45-degree reflector, a convex lens 11, a beam splitter 12, and enters the condenser lens 17. The convex lens 9 and the convex lens 11 are conjugate lens sets configured to convert diverging light from the point light source 8 into parallel light. The point light source 8 emits parallel white light, which is focused at the rear of the sapphire 18 by the condenser lens and reflected onto the beam splitter 12, enters the convex lens 13, and finally reaches the CCD camera 14. By reasonably adjusting a relative distance between the CCD camera 14 and the back of the sapphire 18, the image of the back of the sapphire 18 can be captured by the CCD camera 14.Meanwhile, the near-infrared light emitted by the area light source 22 passes through the mounting table 19, the sapphire 18, the condensed lens 17, the beam splitter 12, and the convex lens 13, finally reaching the CCD camera 14. By appropriately adjusting the relative distance between the CCD camera 14 and the back of the sapphire 18, the image of the back of the sapphire 18 can be captured by the CCD camera 14.

[0022] Referring to Fig. 4 and Fig. 8 The CCD camera 14 can also be used to align the singulation path of the electrode surface on the front face of the sapphire. The front face of the sapphire 18 is composed of individual chip particles arranged periodically. The front face can be singulated along a direction of an a-axis. The singulation path has a certain width. A crosshair is located in the center 21 of the CCD camera, which is used to align and identify the singulation path 2. Before singulation, the center of the CCD camera is aligned with the center of the singulation path 2. In particular, Fig. 8 can be viewed as an image displayed by the monitor of the device 7, in which the central crosshairs of the CCD camera are arranged at the geometric center of the displayed image. The image can be viewed by switching on the area light source 22. Fig. 7 and setting a relative distance between the CCD camera 14 and the surface of the sapphire 18.

[0023] Light from the area light source 22 can penetrate the mounting table and the sapphire 18, allowing the CCD camera 14 to capture images of the plane at various depths along the thickness direction of the sapphire. These images include an electrode pattern on the front of the sapphire, images of the singulation paths, images of the convergent points 4 within the sapphire, and images of the crack on the back of the sapphire, etc. Images at different depths can be acquired by adjusting the relative distance between the CCD camera 14 and the surface of the sapphire 18.In particular, with regard to the crack on the back of the sapphire, the area light source 22 and the point light source 8 can be switched on simultaneously, whereby the focus of the condensed lens is then adjusted to the back of the sapphire and the brightness of the area light source and point source can be adjusted so that the crack can be obtained with the best sharpness for recording by the CCD camera 14. During the manufacturing of the LED chip, the coatings on the back of the sapphire can exhibit differences, which cause different imaging effects. Accordingly, the present invention provides two light sources for imaging in order to resolve the imaging differences due to the coating, so that the cracks on the back of the sapphire can be easily identified and recorded. In addition, the point light source 8 can be a white light source and the area light source 22 can be a near-infrared light source.

[0024] In step 504, an edge detection is performed on the image to obtain a coordinate of a crack.

[0025] In particular, after the device 7 has acquired the image of the sapphire, a denoising treatment is performed on the image, followed by edge detection on the denoised image using an edge detection algorithm. The edge of the crack is determined by the edge detection, and the coordinates of the points at the edge of the crack in the image are determined, forming a set of coordinates.

[0026] In step 506, an offset parameter is determined according to the coordinate of the crack.

[0027] In particular, a center coordinate of the image is recorded, and the coordinates of the points at the edge of the crack are compared with this center coordinate to determine the offset parameter of the crack with respect to the center coordinate of the image. This offset parameter can be used to specify a positional relationship between the crack and the center of the image.

[0028] In step 508, a laser processing position is set according to an offset parameter.

[0029] More precisely, the center point of the image displayed by the device 7 corresponds to the laser processing position, which is the position at which the laser beam 16 is directed into the sapphire. The device 7 can adjust the point of incidence of the laser beam 16 on the sapphire according to the offset parameter.

[0030] In one embodiment, reference is made to Fig. 6 and Fig. 7. The position of the convergent laser points 40' generated within the wafer by the laser 30 is set, and the laser processing position is adjusted so that the crack is oriented towards the intermediate position of the singulation path. In the illustrated embodiment, since the crack 50 generated by processing at the intermediate position O of the singulation path must be shifted to the right, the laser processing device can be moved to the right so that the crack 50' is positioned precisely at the intermediate position O of the singulation path. It should be noted that the distance for moving to the right is no greater than half the width of the singulation path. Additionally, the distance for moving to the right can be the distance between the crack 50 and the intermediate position O of the singulation path.

[0031] In step 510, the sapphire is further processed according to the set laser processing position.

[0032] More precisely, the device 7 controls the laser so that the laser beam 16, which is generated by the laser, is directed onto the sapphire according to the set position.

[0033] In the illustrated embodiment, an image of the sapphire is captured during processing. By analyzing and processing the captured image, the coordinates of the cracks in the sapphire are detected. The offset parameter is determined according to the crack coordinates, allowing the laser processing position to be adjusted accordingly. This offset parameter is ultimately obtained through image processing based on the crack coordinates, thereby improving both the accuracy of the sapphire processing and the quality of the processed sapphire.

[0034] Referring to Fig. In one embodiment, step 504 includes an image processing step which in particular comprises the following: Step 902 generates a grayscale histogram of the image.

[0035] In particular, the device 7 counts the number of pixels of each grayscale value in the recorded image and calculates the frequency of occurrence of each grayscale value according to the number of pixels of each grayscale value, the grayscale histogram then being generated according to the calculated frequency of occurrence of each grayscale value.

[0036] In step 904, a normalization process is performed on the image according to the grayscale histogram.

[0037] In particular, the frequency of each grayscale value in the grayscale histogram is extracted, and the normalization process of the grayscale value is performed on the image according to the frequency of each grayscale value, so that the grayscale difference of the crack in the image becomes more obvious.

[0038] In step 906, edge detection is performed on the normalized image to record the coordinate of the crack.

[0039] In particular, an edge detection algorithm is executed to perform edge detection on the normalized image, so that the edge of the crack on the sapphire in the image is detected and the coordinates of the points on the edge of the crack in the image are extracted.

[0040] In one embodiment, step 906 includes a drag step for an area of ​​interest, which in particular comprises: dragging an area of ​​interest into the normalized image; and performing edge detection on the area of ​​interest to record the coordinate of the crack.

[0041] In one embodiment, step 906 comprises the following steps: performing edge detection on the image to obtain a profile of the crack; and extracting a coordinate of the profile of the crack from the image.

[0042] In particular, the device 7 performs edge detection on the image using a Canny operator (i.e., a multi-stage edge detection algorithm). The edge of the crack in the sapphire in the image is determined using edge detection based on the Canny operator, and the coordinates of the points on the edge of the crack in the image are calculated, forming a coordinate tuple as [(x1,y1), (x2,y2), ......]. Furthermore, the region of interest is drawn into the image, and edge detection is performed on the region of interest using the Canny operator.

[0043] In the illustrated embodiment, the image normalization process ensures a more obvious crack in the image, making it easy to identify. By dragging the area of ​​interest containing the crack according to the normalized image, interference outside the area of ​​interest is reduced, thereby improving the accuracy of the image processing.

[0044] In one embodiment, step 506 includes a step for calculating the offset parameter, which in particular comprises, as follows: Step 1002 yields a center coordinate of the image.

[0045] In particular, the image center coordinate refers to the center of the field of view of the CCD camera 14, which is also the center of the image captured by the CCD camera 14 and displayed by the device 7. The image center corresponds to the laser processing position. The image center can be marked with a special identifier, such as a red dot or a cross. The image center coordinate can be constant, for example, if the coordinate system is established using the image center coordinate as an origin, such that the image center coordinates are (0,0). The image is a partial image of the sapphire taken by the CCD at a certain interval during laser processing. The crack created during the processing of the sapphire can be viewed from the partial image of the sapphire taken by the CCD at a certain interval.In step 1004, an average value of the crack's coordinate is calculated.

[0046] In particular, the coordinates corresponding to the point at the edge of the crack are extracted, and the average value of the coordinate corresponding to another coordinate axis is calculated in each case, and the average value obtained according to the calculation results is considered to be the coordinates of the center point of the cracks.

[0047] In step 1006, the offset parameter is obtained according to the average value and the center coordinate.

[0048] More precisely, the average coordinate value is compared with the center coordinate to determine the relative position of the crack and the center of the image. The center of the image is related to the laser processing position, allowing the offset parameter of the laser processing position and the crack to be obtained.

[0049] In one embodiment, step 1006 comprises: calculating a difference between the average value and the center coordinate; and determining the offset parameter according to the difference, wherein the offset parameter comprises an offset orientation and an offset distance.

[0050] More precisely, the average value of the center of the crack, obtained by calculation, is extracted, the difference between the average value and the center coordinate is calculated, and the offset orientation of the center of the crack with respect to the center of the image is determined according to whether the difference is less than zero, and the offset distance is the absolute value of the difference.

[0051] For example, the set of coordinates of the points at the edge of the crack is [(x1,y1), (x2,y2), ......], the center coordinate of the image is (x0,y0), the average of the y-coordinate values ​​of the points at the edge is compared to a y-coordinate value y0 of the center of the image, the difference (distance) between the average value and y0 is calculated, and the absolute value of the difference (|D|) between the average value and the y0 value is recorded. If the distance is >0, then the crack is offset upwards relative to the center of the image. If the distance is <0, then the crack is offset downwards relative to the center of the image, and the relative offset distance is |D|.

[0052] In one embodiment, step 510 comprises: extracting an offset orientation and an offset distance from the offset parameter; and moving a laser processing position to the offset orientation by a distance equal to the offset distance.

[0053] For example, with reference to Fig. 11, which is an image captured by the CCD camera 14 and displayed on the device 7, shows the crack 1102 in the image being offset downwards with respect to the center of the image. The offset parameter includes the downward offset of the crack 1102 with respect to the center of the image. The crack in the sapphire is moved with respect to the center of the image by adjusting the mounting table, and the movement distance is equal to the offset distance.

[0054] In the illustrated embodiment, the offset parameter of the sapphire crack and the laser processing position are determined by calculation, thus increasing the accuracy of the determination. Additionally, the laser processing position is set to the center of the crack according to the offset parameter, and the sapphire is processed at the crack location, thereby improving the production yield.

[0055] In one embodiment, a laser processing device for the sapphire is provided, comprising a processor and a memory that stores instructions which, when executed by the processor, cause the processor to perform operational sequences, including: capturing an image of the sapphire during processing; performing edge detection on the image to obtain a crack coordinate; determining an offset parameter according to the crack coordinate; setting a laser processing position according to the offset parameter; and further processing the sapphire according to the set laser processing position.

[0056] In one embodiment, capturing the image of the sapphire comprises: processing the sapphire along an intermediate point on a singulation path, thereby forming the crack in the sapphire; and capturing the image of the sapphire with the crack.

[0057] In one embodiment, taking the image of the sapphire with the crack comprises: directing a light source and rays of light generated by the light source onto the sapphire with the crack; and taking the image of the sapphire illuminated by the light.

[0058] In one embodiment, capturing the image of the sapphire illuminated by the light comprises: transmitting an image capture instruction to a CCD camera, and capturing the image of the sapphire illuminated by the light by the CCD camera in a field of view according to the image capture instruction.

[0059] In one embodiment, performing edge detection on the image to obtain the crack coordinate comprises: generating a grayscale histogram of the image; performing a normalization process on the image according to the grayscale histogram; and performing edge detection on the normalized image to obtain the crack coordinate.

[0060] In one embodiment, performing edge detection on the normalized image to obtain the crack coordinate comprises: dragging an area of ​​interest into the normalized image; and performing edge detection on the area of ​​interest to obtain the crack coordinate.

[0061] In one embodiment, performing edge detection on the image to obtain the crack coordinate comprises: performing edge detection on the image to obtain a profile of the crack; and extracting a coordinate of the crack profile from the image.

[0062] In one embodiment, determining an offset parameter according to the coordinate of the crack comprises: recording a center coordinate of the image; calculating an average value of the coordinate of the crack; and recording the offset parameter according to the average value and the center coordinate.

[0063] In one embodiment, taking the offset parameter according to the average value and the center coordinate comprises: calculating a difference between the average value and the center coordinate; and determining the offset parameter according to the difference, wherein the offset parameter comprises an offset orientation and an offset distance.

[0064] In one embodiment, setting a laser processing position according to the offset parameter comprises: extracting an offset orientation and an offset distance from the offset parameter; and moving a laser processing position to the offset orientation by a distance equal to the offset distance.

[0065] In the illustrated embodiment, an image of the sapphire is captured during processing. By analyzing and processing the captured image, the coordinates of the cracks in the sapphire are detected. The offset parameter is determined according to the crack coordinates, allowing the laser processing position to be adjusted accordingly. This offset parameter is ultimately obtained through image processing based on the crack coordinates, thereby improving both the accuracy of the sapphire processing and the quality of the processed sapphire.

[0066] In one embodiment, a non-volatile, computer-readable medium is included that stores instructions which, when executed by one or more processors, cause the one or more processors to perform the following operations: capturing an image of the sapphire during processing; performing edge detection on the image to obtain a crack coordinate; determining an offset parameter according to the crack coordinate; setting a laser processing position according to the offset parameter; and further processing the sapphire according to the set laser processing position.

[0067] In the illustrated embodiment, an image of the sapphire is captured during processing. By analyzing and processing the captured image, the coordinates of the cracks in the sapphire are detected. The offset parameter is determined according to the crack coordinates, allowing the laser processing position to be adjusted accordingly. This offset parameter is ultimately obtained through image processing based on the crack coordinates, thereby improving both the accuracy of the sapphire processing and the quality of the processed sapphire.

[0068] Embodiments of the invention can be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the invention can also be implemented as instructions stored on a machine-readable medium that can be read and executed by one or more processors. A machine-readable medium can comprise any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine-readable medium can include read-only memory (ROM); random-access memory (RAM); a magnetic disk storage medium; optical storage media; flash memory devices; electrical, optical, acoustic, or other forms of propagating signals (e.g., carrier waves, infrared signals, digital signals, etc.); and others.

[0069] Although the respective embodiments are described sequentially, it should be noted that the respective embodiments are not isolated. A person skilled in the art can see from reading the disclosure of this application that the respective technical features affected in the respective embodiments can be combined arbitrarily between the respective embodiments, as long as no conflict arises between them. Naturally, the respective technical features mentioned in the same embodiment can also be combined arbitrarily, as long as no conflict arises between them.

[0070] Although the description is presented and described here with reference to specific embodiments, it is not intended to be limited to the details shown. Modifications to the details may be made within the scope of protection and area equivalents of the claims.

Claims

[1] Laser processing methods for a sapphire, comprising: Taking an image of the sapphire (18) during processing (502) characterized by Performing edge detection on the image to obtain a coordinate of a crack (5, 50) (504) Determining an offset parameter according to the coordinate of the crack (5, 50) (506); Setting a laser processing position according to the offset parameter (508), and Further processing of the sapphire (18) according to the set laser processing position (510) where determining the offset parameter includes: Taking a center coordinate of the image (1002); Calculating an average value of the coordinate of the crack (5, 50) (1004); and Taking the offset parameter according to the average value and the center coordinate (1006), where calculating the average value of the crack coordinate (5, 50) includes: Extracting the coordinates corresponding to the point on the edge of the crack (5, 50); and Calculating an average value of the coordinates according to the different coordinate axes. [2] Method according to claim 1, wherein the taking of the image of the sapphire (18) comprises: Machining the sapphire (18) along an intermediate point of a singulation path (2, 20) thereby forming the crack (5, 50) on the sapphire (18); and recording the image of the sapphire (18) with the crack (5, 50) [3] Method according to claim 2, wherein taking the image of the sapphire (18) with the crack (5, 50) comprises: Controlling a light source (8, 22) and emitting light generated by the light source (8, 22) onto the sapphire (18) with the crack (5, 50); and Taking the image of the sapphire illuminated by the light (18) [4] Method according to claim 3, wherein the taking of the image of the sapphire (18) illuminated by the light comprises: Transmitting an image acquisition instruction to a CCD camera (14) and capturing the image of the sapphire (18) illuminated by the light by the CCD camera (14) in a field of view according to the image acquisition instructions. [5] Method according to claim 1, wherein performing the edge detection on the image to obtain the coordinate of the crack (5, 50) comprises: Generating a grayscale histogram of the image; Performing a normalization process on the image according to the grayscale histogram; and Perform edge detection on the normalized image to obtain the crack coordinate (5, 50). [6] Method according to claim 5, wherein performing the edge detection on the normalized image to obtain the coordinate of the crack (5, 50) comprises: Dragging an area of ​​interest into the normalized image; and Perform edge detection on the area of ​​interest to obtain the coordinate of the crack (5, 50). [7] Method according to claim 1, wherein performing edge detection on the image to obtain the coordinate of the crack (5, 50) comprises: Performing edge detection on the image to obtain a profile of the crack (5, 50); and Extracting a coordinate of the profile of the crack (5, 50) in the image. [8] Method according to claim 1, wherein recording the offset parameter according to the average value and the center coordinate comprises: Calculating the difference between the average value and the midpoint coordinate; and Determining the offset parameter according to the difference, where the offset parameter includes an offset orientation and an offset distance. [9] Method according to claim 1, wherein setting a laser processing position according to the offset parameter comprises: Extracting an offset orientation and an offset distance from the offset parameter; and Moving a laser processing position relative to the offset orientation by a distance equal to the offset distance. [10] Laser processing device for a sapphire, comprising: a processor; and a memory that stores instructions which, when executed by the processor, cause the processor to execute the method according to any one of claims 1 to 9. [11] Non-volatile computer-readable medium storing instructions which, when executed by one or more processors, cause one or more processors to execute the method according to any one of claims 1 to 9.

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