Image acquisition device, silicon wafer detection equipment and silicon wafer detection method

Abstract

The invention relates to an image acquisition device, silicon wafer detection equipment and a silicon wafer detection method. The image acquisition device comprises a rack, a silicon wafer conveying line penetrates through the rack in the conveying direction of a silicon wafer group, and the silicon wafer group comprises a plurality of silicon wafers stacked in the vertical direction; and the at least one line scanning detection unit is installed on the rack, the lens shooting direction of the line scanning detection unit is parallel to the conveying plane of the silicon wafer group, and the line scanning detection unit is used for collecting edge images of the silicon wafer group in the vertical direction. By applying the image acquisition device, the image acquisition and identification efficiency and the defect detection efficiency can be improved under the condition that the image pixel precision is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon wafer detection, and in particular to an image acquisition device, silicon wafer detection equipment and a silicon wafer detection method. Background Art

[0002] During the production of silicon wafers, since the sorting machine may miss inspections or cause secondary damage during sorting, it is necessary to manually re-inspect the whole stack of sorted silicon wafers to check for defects such as edge collapse, silicon drop, and dirt, which affect production efficiency. Therefore, how to carefully inspect the entire group of silicon wafers and achieve manual inspection-free whole machine is of great research significance.

[0003] The related art discloses that a camera is set up to take photos of silicon wafers at a detection station. However, since the detection object is a silicon wafer group, how to quickly collect and detect silicon wafer information becomes a problem that needs to be solved urgently.

[0004] There is no effective solution to the problem of low efficiency of silicon wafer detection in related technologies. Summary of the invention

[0005] Based on this, it is necessary to provide an image acquisition device, a silicon wafer detection equipment and a silicon wafer detection method to address the problem of low silicon wafer detection efficiency.

[0006] In a first aspect, an embodiment of the present disclosure provides an image acquisition device, which is applied to a silicon wafer conveyor line, wherein the silicon wafer detection device comprises: a rack, wherein the silicon wafer conveyor line passes through the rack along a transport direction of a silicon wafer group, wherein the silicon wafer group comprises a plurality of silicon wafers stacked in a vertical direction; At least one line scan detection unit is installed on the frame, the lens shooting direction of the line scan detection unit is parallel to the transportation plane of the silicon wafer group, and the line scan detection unit is used to move in the vertical direction to collect the edge image of the silicon wafer group.

[0007] The image acquisition device provided in the embodiment of the present disclosure performs line scan image acquisition on a whole group of stacked silicon wafers based on a line scan detection unit moving in the vertical direction. Since the detection of a whole group of silicon wafers in the photovoltaic industry is usually 150 pieces per group of 210mm silicon wafers, compared with the conventional area array camera detection scheme and the horizontal line scan detection scheme, the vertical line scan detection scheme adopted in this embodiment can greatly reduce the image size while ensuring sufficient pixel accuracy, so that the processing speed of the image analysis algorithm is significantly improved, and the configuration requirements for the hardware such as the industrial computer CPU and the graphics card are greatly reduced, thereby improving the detection efficiency.

[0008] In one embodiment, the frame includes a lifting assembly and at least two groups of supporting assemblies; the supporting assemblies are arranged on both sides of the silicon wafer conveyor line; the lifting assembly is located above the silicon wafer conveyor line and is connected to the supporting assemblies on both sides of the silicon wafer conveyor line, and the lifting assembly is used to load the line scan detection unit and move it along the vertical direction.

[0009] In one embodiment, the support assembly includes at least two support columns and at least one connecting column; the arrangement direction of at least two of the support columns is parallel to the extension direction of the silicon wafer conveyor line, and the bottom end of the support column is fixed; the two ends of the connecting column are respectively connected to the top end of the support column, and the extension direction of the connecting column is parallel to the extension direction of the silicon wafer conveyor line.

[0010] In one embodiment, the frame also includes a guide assembly, which includes a plurality of guide rails and sliding members; the guide rails are arranged on the opposite side of the support column located on the same side of the silicon wafer conveyor line, and the guide rails extend in the vertical direction; one side of the sliding member is arranged on the lifting assembly, and the other side is slidably connected to the guide rail, so that the lifting assembly rises or falls along the extension direction of the guide rail when moving.

[0011] In one embodiment, the lifting assembly includes a driving member and a loading member; the driving member is fixed to the supporting assembly; the loading member is connected to the driving member and rises or falls under the drive of the driving member.

[0012] In one embodiment, the image acquisition device further includes a chamfer detection unit, and the chamfer detection unit is disposed relative to the lifting assembly along a diagonal direction of the silicon wafer group.

[0013] In one embodiment, the image acquisition device also includes an in-place detection unit, which includes a first mounting column and an identification member, wherein both ends of the first mounting column are respectively connected to support assemblies disposed on both sides of the silicon wafer conveyor line, and the identification member is fixed to the first mounting column and the shooting direction of the identification member is located in the same plane as the silicon wafer conveyor line.

[0014] In one embodiment, the image acquisition device also includes a pressing unit, which includes a lifting member, a second mounting column and a limiting member; the lifting member is arranged in a hollow portion between the silicon wafer conveying lines, the bottom end of the lifting member is fixed, and the top end passes through the hollow portion to lift the silicon wafer group on the silicon wafer conveying line when the lifting member is in an extended state; the two ends of the second mounting column are connected to the supporting components arranged on both sides of the silicon wafer conveying line; the limiting member and the lifting member are arranged on the second mounting column relatively along the vertical direction to cooperate with the lifting member to clamp the silicon wafer group.

[0015] In the second aspect, the present embodiment further provides a silicon wafer inspection device, which includes an image acquisition device as described in any embodiment of the first aspect above, and the silicon wafer inspection device also includes: a control unit, used to control the image acquisition device to acquire a silicon wafer image and send the silicon wafer image to an image recognition unit; an image recognition unit, used to acquire a silicon wafer image and perform defect detection based on the silicon wafer image.

[0016] In the third aspect, the present embodiment also provides a silicon wafer detection method, which includes: an in-place detection unit obtains position information of a silicon wafer group, a lifting unit and a pressing unit press the silicon wafer group based on the position information, a chamfer detection unit performs image acquisition on the pressed silicon wafer group to obtain a chamfer image; a line scan detection unit moves in a vertical direction and simultaneously performs image acquisition on the pressed silicon wafer group to obtain an edge image; an image recognition unit performs silicon wafer defect detection based on the chamfer image and the edge image.

[0017] The above-mentioned image acquisition device uses a vertical line scanning method to capture silicon wafer images of a whole group of stacked silicon wafers. On the basis of ensuring pixel requirements, it reduces the storage volume of the image, helps to improve the algorithm processing speed, and reduce the processing pressure of hardware such as industrial computers, CPUs, and graphics cards, thereby greatly improving the inspection efficiency of silicon wafer groups on the production line. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a structural schematic diagram of an image acquisition device according to an embodiment of the present application; Figure 2 is a schematic diagram of the structure of a rack according to an embodiment of the present application; Figure 3 is a schematic structural diagram of a support assembly according to an embodiment of the present application; Figure 4 is a schematic structural diagram of a guide assembly according to an embodiment of the present application; Figure 5 is a schematic structural diagram of a lifting assembly according to an embodiment of the present application; Figure 6 is a structural schematic diagram of a chamfer detection unit according to an embodiment of the present application; Figure 7 is a structural schematic diagram of an in-place detection unit according to an embodiment of the present application; Figure 8 is a schematic structural diagram of a pressing unit according to an embodiment of the present application; Fig. 9 A schematic diagram of an edge image of a silicon wafer assembly according to an embodiment of the present application; Fig.10is a schematic structural diagram of a silicon wafer inspection device according to an embodiment of the present application; Fig.11 Schematic diagram of a silicon wafer detection method according to an embodiment of the present application; Fig.12 4 is a flow chart of a silicon wafer inspection method according to another embodiment of the present application.

[0019] Explanation of the accompanying drawings: 100, silicon wafer conveyor line; 200, frame; 300, line scan detection unit; 201, lifting assembly; 2011, driving member; 2012, loading member; 202, supporting assembly; 2021, supporting column; 2022, connecting column; 203, guiding assembly; 2031, guide rail; 2032, sliding member; 400, chamfering detection unit; 500, in-place detection unit; 501, first mounting column; 502, identification member; 600, pressing unit; 601, lifting member; 602, second mounting column; 603, limiting member; 10, image acquisition device; 20, control unit; 30, image recognition unit. DETAILED DESCRIPTION

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0021] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0023] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0025] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0026] Silicon wafers are generally slices of single crystal silicon, which are important materials for making integrated circuits and photovoltaic cells. Throughout the entire process of silicon wafer production, from cutting to cleaning to transmission on the entire production line, defect detection is an indispensable link. Generally, after the silicon wafers are cleaned, they need to be graded by silicon wafer sorting equipment, that is, they are grouped based on the final quality of the silicon wafers to meet the quality requirements of different productions. After the silicon wafers are sorted, the silicon wafers are placed in a material box in the form of multiple stacks. The silicon wafers in the material box need to be taken out and packaged. In order to detect and identify the transportation loss during the period from silicon wafer sorting to packaging, the silicon wafers need to be inspected for defects again. Based on this, the present application provides an image acquisition device, a silicon wafer detection device, and a silicon wafer detection method to improve the detection efficiency of the entire group of silicon wafers.

[0027] See also Figures 1 to 9The present invention provides an image acquisition device, which is applied to a silicon wafer conveyor line 100. The image acquisition device includes: a rack 200, and the silicon wafer conveyor line 100 runs through the rack 200 along the transportation direction of the silicon wafer group. The rack 200 is used to fix and install various detection units and execution structures required for image acquisition. The rack 200 is fixedly set on a machine table or the ground. The silicon wafer group includes a plurality of silicon wafers stacked in a vertical direction. In one specific embodiment, the silicon wafer group includes 150 silicon wafers sorted by a silicon wafer sorting device, and the single wafer specification is 210mm*210*0.15mm. The length, width and height of the entire group of silicon wafers are 210mm*210mm*22.5mm. The silicon wafer group is placed on the silicon wafer conveyor line 100 manually or by a robot. The silicon wafer conveyor line 100 is composed of one or more conveyor belts.

[0028] This embodiment uses at least one line scan detection unit 300 to image the edge of the silicon wafer group. The line scan detection unit 300 includes a line array camera. The line scan detection unit 300 is installed on the rack 200. The shooting direction of the lens of the line scan detection unit 300 is parallel to the transportation plane of the silicon wafer group. The lens shooting direction refers to the direction in which the lens of the line scan camera is facing. The line scan detection unit 300 can be raised and lowered in the vertical direction under the drive of the electric drive mechanism of the rack 200, so as to collect the edge image of the silicon wafer group in the vertical direction. The number of the line scan detection units 300 is one or more. Preferably, the number of the line scan detection units 300 is four, wherein two line scan detection units 300 are arranged relatively to each other along the transport direction of the silicon wafer group, and the other two line scan detection units 300 are arranged relatively to each other along the direction orthogonal to the transport direction in the transport plane of the silicon wafer group. When the silicon wafer group is located at the detection position, the four line scan detection units 300 respectively correspond to the front side, the rear side, the left side and the right side of the silicon wafer group, and the line scan detection units 300 photograph the silicon wafer group to obtain an edge image of the silicon wafer group.

[0029] The image acquisition device of this embodiment acquires the edge image of the silicon wafer group along the vertical direction through the line scan detection unit 300, which can reduce the image volume while ensuring the pixel accuracy of the image, thereby improving the image recognition efficiency and the detection efficiency of the silicon wafer group.

[0030] In the field of photovoltaic silicon wafer inspection, the commonly used single silicon wafer specifications are 210mm*210*0.15mm, and silicon wafers are mostly packaged in groups of 150 wafers. The length, width and height of the whole group of silicon wafers are 210mm*210mm*22.5mm. When it is necessary to inspect the entire group of silicon wafers, machine vision technology is mostly used for defect identification. Therefore, the image acquisition efficiency and the image volume directly affect the efficiency of image recognition by the image processing algorithm. When performing camera imaging, the commonly used detection cameras can be divided into two types according to the arrangement of their photosensitive units. One is a planar array camera, which uses a flying shooting method to collect images; the other is a linear array camera, which uses a horizontal scanning method to collect images. Under the premise of ensuring the pixel accuracy of the image, the images collected by the two cameras and the corresponding shooting methods are compared in this embodiment. Based on the comparison results, it can be determined that the image acquisition device of this embodiment can effectively improve the image acquisition effect and improve the detection efficiency of the silicon wafer group.

[0031] Taking the image acquisition requirements of a silicon wafer group with a length, width and height of 210mm*210mm*22.5mm as an example, the adapter camera must meet the following conditions: the camera field of view height only needs to cover the height of the silicon wafer. The conventional inspection object is a 22.5mm silicon wafer group, so the camera field of view height is set to 40mm. The scanning length covers the length of the silicon wafer and is set to 230mm. The resulting magnification is 0.7168.

[0032] Based on the preset conditions, an adapted area array camera is selected. When the area array camera is a 5-megapixel camera, the camera target surface size is 2 / 3", and the resolution is 2448×2048. The horizontal dimension of the field of view is 230 mm, the vertical dimension is 192 mm, the magnification is 0.03672, and the camera frame rate is 24.2 FPS. In this embodiment, the pixel accuracy is the ratio of the resolution to the field of view size. Therefore, the pixel accuracy of the camera imaging is only 2048÷192=10.6 pixels / mm. Furthermore, the number of pixels in the thickness direction of each silicon wafer is 10.6×0.15=1.59 pixels, and the shooting time is 1÷24.2=0.04s. Image size = 5000000×3÷1024÷1024=15MB.

[0033] Based on the above preset conditions, an adapted area array camera is selected. When the area array camera is a 12-megapixel camera, its target surface size is 1 / 1", and its resolution is 4096×3000. Correspondingly, the horizontal dimension of the camera's field of view is 230mm, the vertical dimension is 168mm, the magnification is 0.06144, and the camera frame rate is 9.4FPS. The imaging accuracy of the camera is 3000÷168=17.8 pixels / mm, the number of pixels in the thickness direction of each silicon wafer is: 17.8×0.15=2.67 pixels, the shooting time = 1÷9.4=0.1s, and the image size is 12000000×3÷1024÷1024=36MB.

[0034] Based on the above preset conditions, an adapted 4K line scan camera is selected, and when the horizontal line scan method is used for image acquisition, the resolution of the 4K line scan camera is 4096×2, and the moving speed is 600mm / s. When the line scan direction is horizontal to the long side of the silicon wafer, the field of view length only needs to cover the height of the silicon wafer, which can be set to 40mm, and the line scan distance covers the length of the silicon wafer, which is set to 230mm. The imaging magnification of the camera is 0.7168, the pixel accuracy of the imaging is 4096÷40=102.4 pixels / mm, the number of pixels in the thickness direction of each silicon wafer is 102.4×0.15=15.36 pixels, the shooting time is 230÷600=0.383s, and the image size is 4096×102.4×230×3÷1024÷1024=276MB.

[0035] Based on the above preset conditions, a suitable 4K line scan camera is selected, and when the vertical line scan method is used for image acquisition, the resolution of the 4K line scan camera is 4096×2, and the moving speed is 600mm / s. If the line scan direction is horizontal to the thickness direction of the silicon wafer, the line scan distance needs to cover the height of the silicon wafer, which can be set to 40mm, and the field of view length needs to cover the length of the silicon wafer, which is set to 230mm. The magnification of the camera imaging is 0.124, and the imaging accuracy is 4096÷230=17.8 pixels / mm. The number of pixels in the thickness direction of each silicon wafer is 17.8×0.15=2.67 pixels, the shooting time = 40÷600=0.067s, and the image size = 4096×17.8×40×3÷1024÷1024=8MB.

[0036] As can be seen from the above, in the shooting scheme of the area array camera, the pixel accuracy of the image is limited by the camera accuracy. The pixel accuracy of the 5-megapixel area array camera is low and it is difficult to meet the image requirements of the actual measurement. Therefore, the relatively preferred scheme is the image acquisition scheme of the 12-megapixel area array camera. In the shooting scheme of the linear array camera, the vertical shooting method adopted in the embodiment of the present application can greatly shorten the image shooting time and reduce the image volume while ensuring pixel accuracy compared to the horizontal shooting method. At the same time, the vertical line scanning shooting scheme adopted in the embodiment of the present application has a shorter shooting time and a smaller image volume under the condition of achieving the same shooting accuracy as the 12-megapixel area array camera. Therefore, the image acquisition device based on the embodiment of the present application can greatly reduce the image volume while ensuring sufficient pixel accuracy, improve the algorithm processing speed, reduce the performance requirements for industrial computer CPU, graphics card and other equipment, and reduce the equipment cost. In addition, due to the shortened image shooting time, the detection efficiency of the silicon wafer group can be greatly improved.

[0037] In one embodiment, Figure 2 As shown, the rack 200 includes a lifting assembly 201 and at least two groups of support assemblies 202; the support assemblies 202 are arranged on both sides of the silicon wafer conveyor line 100; the lifting assembly 201 is located above the silicon wafer conveyor line 100 and connected to the support assemblies 202 on both sides of the silicon wafer conveyor line 100, and the lifting assembly 201 is used to load the line scan detection unit 300 and move it in the vertical direction. Specifically, the support assemblies 202 arranged on both sides of the silicon wafer conveyor line 100 cooperate to form an outer frame, and the lifting assembly 201 serves as an inner frame to load and move the line scan detection unit 300 to realize the acquisition of the silicon wafer group image. Based on the rack 200 structure of this embodiment, the modular design of the rack 200 is realized, which is convenient for the assembly and later maintenance of the equipment and reduces the maintenance cost.

[0038] In one embodiment, Figure 3 As shown, the support assembly 202 includes at least two support columns 2021 and at least one connecting column 2022; the support columns 2021 and the connecting columns 2022 can be cylindrical or square. The arrangement direction of at least two support columns 2021 is parallel to the extension direction of the silicon wafer conveyor line 100, and the bottom end of the support column 2021 is fixed. The bottom end of the support column 2021 is fixed to the machine or the ground, and the fixing method includes but is not limited to bolt fixing or pin fixing. The two ends of the connecting column 2022 are respectively connected to the top of the support column 2021, and the extension direction of the connecting column 2022 is parallel to the extension direction of the silicon wafer conveyor line 100.

[0039] In one preferred embodiment, the rack 200 includes two groups of support components 202, which are arranged on both sides of the silicon wafer conveyor line 100. Each group of support components 202 includes two square support columns 2021 and a square connecting column 2022. The bottom end of the square support column 2021 is fixed to the machine platform, and the square connecting column 2022 is arranged on the side of the square support column 2021 away from the silicon wafer conveyor line 100 and the two ends of the square connecting column 2022 are respectively connected to the top of the two square support columns 2021.

[0040] In one embodiment, Figure 4 As shown, the rack 200 further includes a guide assembly 203, which includes a plurality of guide rails 2031 and a sliding member 2032; the guide rails 2031 are arranged on the opposite side of the support column 2021 located on the same side of the silicon wafer conveyor line 100, and the guide rails 2031 extend in the vertical direction; one side of the sliding member 2032 is arranged on the lifting assembly 201, and the other side is slidably connected with the guide rails 2031, so that the lifting assembly 201 moves up or down along the extension direction of the guide rails 2031. By providing the guide assembly 203, the stability of the lifting assembly 201 when moving can be improved, and the imaging effect of the line scan camera when taking pictures can be enhanced.

[0041] In one embodiment, Figure 5 As shown, the lifting assembly 201 includes a driving member 2011 and a loading member 2012; the driving member 2011 may be a cylinder or a motor, which is connected to an electric control mechanism and starts and stops the driving member 2011 based on the received electric control signal. The driving member 2011 is fixed to the supporting assembly 202; the loading member 2012 is connected to the driving member 2011 and rises or falls under the drive of the driving member.

[0042] In one preferred embodiment, the driving member 2011 is a cylinder, which is fixedly arranged on the side of the connecting column 2022 close to the silicon wafer conveyor line 100. A gas rod is arranged in the cylinder, and the gas rod is connected to the loading member 2012. When the gas rod extends or contracts in the cylinder, it drives the loading member 2012 to rise or fall. The loading member 2012 is used to install the line scan detection unit 300. When the loading member 2012 moves, the line scan detection unit 300 is driven to rise or fall accordingly to perform image acquisition. Further, a guide rail 2031 is arranged on the side wall of the support column 2021, and a slider is built in the guide rail 2031, and the slider is also connected to the loading member 2012. When the driving member 2011 drives the loading member 2012 to move, the loading member 2012 moves smoothly along the direction guided by the guide rail 2031.

[0043] In one embodiment, Figure 6 As shown, the image acquisition device further includes a chamfer detection unit 400, which is disposed relatively to the lifting assembly 201 along the diagonal direction of the silicon wafer group.

[0044] Specifically, the chamfer detection unit 400 is used to detect the chamfer of the silicon wafers in the silicon wafer group. The chamfer detection unit 400 includes a light source, an image sensor, etc. The light source is used to increase the ambient brightness around the silicon wafer group; the image sensor is used to collect the photographic detection of the chamfer of the silicon wafer group, and identify defects such as corner chipping and debris through machine vision technology. Preferably, the number of chamfer detection units 400 is 4 groups, and each group of chamfer detection units 400 is arranged at a chamfer interval of the silicon wafer group on the lifting assembly 201.

[0045] In one embodiment, a multi-directional adjustment mechanism is further provided at the connection between the chamfer detection unit 400 and the lifting assembly 201 to adjust the shooting angle of the chamfer detection unit 400. The chamfer detection unit 400 and the line scan detection unit 300 cooperate to improve the defect detection capability of the silicon wafer group.

[0046] In one embodiment, Figure 7 As shown, the image acquisition device also includes an in-place detection unit 500, which includes a first mounting column 501 and an identification member 502. Both ends of the first mounting column 501 are respectively connected to support assemblies 202 arranged on both sides of the silicon wafer conveyor line 100. The identification member 502 is fixed to the first mounting column 501 and the shooting direction of the identification member 502 is located in the same plane as the silicon wafer conveyor line 100.

[0047] Specifically, the in-place detection unit 500 is used to detect whether the silicon wafer group is transported to the detection station. The detection station is a position set for performing silicon wafer quality detection on the silicon wafer group. The identification member 502 is a position sensor, including one or more of an image sensor, a laser sensor, and a Hall sensor, for performing in-place detection on the silicon wafer group.

[0048] In one preferred embodiment, the identification element 502 includes a light source and a camera lens. The light source is used to increase the ambient brightness near the silicon wafer group. The camera lens is used to capture an image of the top of the silicon wafer group, especially the image of the first silicon wafer at the top of the silicon wafer group. The image of the first silicon wafer can be used to characterize the quality level of the entire group of silicon wafers. By detecting indicators such as color difference, line mark direction, and line mark length in the image of the first silicon wafer at the top of the silicon wafer group, and comparing these indicators with the incoming material information provided by the front-end sorting machine, the identity information of the current silicon wafer group can be determined. The in-place detection unit 500 of this embodiment helps to improve the automation level of the equipment, and at the same time, improves the level of information flow in the silicon wafer sorting and packaging process, which helps to strengthen the production information management and control of the silicon wafer production line.

[0049] In one embodiment, Figure 8As shown, the image acquisition device also includes a pressing unit 600, which includes a lifting member 601, a second mounting column 602 and a limiting member 603; the lifting member 601 is arranged in the hollow part between the silicon wafer conveyor lines 100, the bottom end of the lifting member 601 is fixed, and the top end passes through the hollow part to lift the silicon wafer group on the silicon wafer conveyor line 100 when the lifting member 601 is in an extended state; the two ends of the second mounting column 602 are connected to the support components 202 arranged on both sides of the silicon wafer conveyor line 100; the limiting member 603 and the lifting member 601 are arranged on the second mounting column 602 in a vertical direction relative to each other, so as to cooperate with the lifting member 601 to clamp the silicon wafer group.

[0050] Specifically, the lifting member 601 includes a lifting cylinder and a lifting telescopic rod; the lifting cylinder is fixedly installed on the machine or the silicon wafer conveyor line, and the lifting telescopic rod is used to extend or contract under the drive of the lifting cylinder. The lifting member 601 lifts the silicon wafer group from the silicon wafer conveyor line 100 to separate the silicon wafer group from the silicon wafer conveyor line 100. The lifting member 601 and the limiting member 603 cooperate to press the silicon wafer group, and the silicon wafer group is pressed and positioned to achieve the effect of eliminating the air gap between the silicon wafers. Fig. 9 As shown, due to certain warping of silicon wafers, the presence of silicon powder or fine silicon particles between wafers, and the inability to completely eliminate the air layer between wafers, the imaging of the whole stack of silicon wafers will show black gaps. When encountering a situation where the gap between silicon wafers is large, especially when the size of the gap between silicon wafers is close to the thickness of the silicon wafers, the black gap is easily misjudged as a defect. In this embodiment, by pressing and positioning the silicon wafer group, the close combination of each silicon wafer in the silicon wafer group is achieved, which can effectively reduce the impact of the gap between wafers on the whole stack of silicon wafers, improve the accuracy of silicon wafer detection, and reduce the misjudgment rate. At the same time, the cooperation of the lifting member 601 and the limiting member 603 can keep the silicon wafer relatively still, and when the line scanning detection unit 300 performs detection in a vertical lifting manner, the stability of the imaging quality can be guaranteed.

[0051] In one embodiment, an image acquisition device is provided, such as Figure 1As shown, the image acquisition device includes a frame 200, an in-position detection unit 500, a pressing unit 600, a line scan detection unit 300 and a chamfer detection unit 400. Among them, the frame 200 includes an outer frame, an inner frame and a guide assembly 203. The outer frame includes support assemblies 202 arranged on both sides of the silicon wafer conveyor line, and each group of support assemblies 202 includes two support columns 2021 and a connecting column 2022. The bottom ends of the support columns 2021 are fixed to the machine table through angle seats. The two ends of the connecting column 2022 are connected to the top ends of the two support columns 2021 on the side of the support column 2021 away from the silicon wafer conveyor line 100. The two groups of support assemblies 202 cooperate to form an outer frame. The inner frame is a lifting assembly 201, which includes a loading part 2012 for installing the line scan detection unit 300 and the chamfer detection unit 400 and a driving part 2011 for driving the device to move up and down. The driving member 2011 is a lifting cylinder, there are two of them, which are installed on the opposite side of the connecting column of the support assembly 202. The loading member 2012 is a ring structure surrounded by four square columns. The square column is parallel or perpendicular to the direction of the silicon wafer conveyor line 100. The corner of the ring structure is connected to the guide assembly 203 through a mounting plate. Based on this ring structure, four first mounting plates and four second mounting plates are also installed. The first mounting plate is used to install the line scan detection unit 300, and the second mounting plate is used to install the chamfer detection unit 400. Through the image acquisition device of this embodiment, the outer frame is used to install and fix each positioning mechanism and the identification mechanism, and the inner frame is used to lift and collect the image of the silicon wafer group. Through four groups of line scan detection units 300 and four groups of chamfer detection units 400, the edge and chamfer detection of the silicon wafer can be realized at the same time.

[0052] This embodiment also provides a silicon wafer detection device, such as Fig.10 As shown, the silicon wafer inspection device includes an image acquisition device 10 as described in any of the above embodiments, and the silicon wafer inspection device also includes: a control unit 20, used to control the image acquisition device 10 to obtain a silicon wafer image and send the silicon wafer image to an image recognition unit 30; the image recognition unit 30, used to obtain a silicon wafer image and perform defect detection based on the silicon wafer image.

[0053] Specifically, the control unit 20 is an industrial computer, a processor, a PLC, etc. The image recognition unit 30 can be a processor, a microprocessor or an industrial computer, etc., which is used to process and recognize the silicon wafer image collected by the image acquisition device, perform image processing based on preset defect recognition rules or pre-trained deep learning models, detect whether the current silicon wafer image has defects, and then complete defect detection of the silicon wafer group.

[0054] This embodiment also provides a silicon wafer detection method, such as Fig.11 As shown, the silicon wafer detection method includes: Step S101, the in-place detection unit obtains the position information of the silicon wafer group; Step S102, the pressing unit presses the silicon wafer group based on the position information; Step S103, the chamfer detection unit and the line scan detection unit move in the vertical direction to collect the chamfer image and edge image of the silicon wafer group; In step S104 , the image recognition unit performs silicon wafer defect detection based on the chamfer image and the edge image.

[0055] In one embodiment, Fig.12 As shown, the silicon wafer detection method includes: Step S201: The robot moves the silicon wafer group to the silicon wafer conveyor line.

[0056] Step S202: The silicon wafer conveyor line transports the silicon wafer group along a preset direction.

[0057] Step S203: The arrival detection unit detects whether the silicon wafer group has arrived at the detection station.

[0058] Specifically, the in-place detection unit is located above the detection station to take pictures and image the first silicon wafer on the top of the silicon wafer group to represent the entire stack of silicon wafers in the silicon wafer group, detect color difference, line mark direction, etc., and compare and verify it with the incoming material information provided by the upstream sorting machine.

[0059] Step S204: the pressing unit lifts up the silicon wafer group and clamps it.

[0060] Specifically, the lifting unit lifts the silicon wafer to separate the silicon wafer group from the silicon wafer conveyor line, and the pressing unit presses down to discharge the air between the silicon wafers and eliminate the black gap, thereby keeping the silicon wafer group in a pressed state during the entire shooting process. In one embodiment, the pressing unit can also be fixed to the frame and only relatively moved by the lifting unit.

[0061] Step S205 , the lifting assembly moves in a vertical direction, driving the line scan detection unit to take an edge image of the silicon wafer assembly; and driving the chamfer detection unit to take a chamfer image of the silicon wafer assembly.

[0062] Step S206 : the image recognition unit performs silicon wafer defect detection based on the chamfer image and the edge image.

[0063] Step S207, after the detection is completed, the lifting member of the pressing unit descends, driving the silicon wafer group back to the silicon wafer conveying line.

[0064] The above-mentioned image acquisition device uses a vertical line scanning method to capture silicon wafer images of a whole group of stacked silicon wafers. On the basis of ensuring pixel requirements, it reduces the storage volume of the image, helps to improve the algorithm processing speed, and reduce the processing pressure of hardware such as industrial computers, CPUs, and graphics cards, thereby greatly improving the inspection efficiency of silicon wafer groups on the production line.

[0065] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0066] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An image acquisition device, applied to a silicon wafer conveyor line, characterized in that: The image acquisition device comprises: A rack, wherein the silicon wafer conveyor line passes through the rack along a transport direction of a silicon wafer group, wherein the silicon wafer group includes a plurality of silicon wafers stacked in a vertical direction; At least one line scan detection unit is installed on the frame, the lens shooting direction of the line scan detection unit is parallel to the transportation plane of the silicon wafer group, and the line scan detection unit is used to move in the vertical direction to collect the edge image of the silicon wafer group.

2. The image acquisition device according to claim 1, characterized in that: The frame includes a lifting assembly and at least two sets of supporting assemblies; The support components are arranged on both sides of the silicon wafer conveying line; The lifting assembly is located above the silicon wafer conveying line and is connected to the supporting assemblies on both sides of the silicon wafer conveying line. The lifting assembly is used to load the line scanning detection unit and move it along the vertical direction.

3. The image material device according to claim 2, characterized in that: The support assembly includes at least two support columns and at least one connecting column; The arrangement direction of at least two of the support columns is parallel to the extension direction of the silicon wafer conveying line, and the bottom ends of the support columns are fixed; Both ends of the connecting column are respectively connected to the top of the supporting column, and the extending direction of the connecting column is parallel to the extending direction of the silicon wafer conveying line.

4. The image acquisition device according to claim 3, characterized in that: The frame further comprises a guide assembly, wherein the guide assembly comprises a plurality of guide rails and sliding members; The guide rail is arranged on the opposite side of the support column located on the same side of the silicon wafer conveying line, and the guide rail extends in the vertical direction; One side of the sliding member is arranged on the lifting assembly, and the other side is slidably connected with the guide rail, so that the lifting assembly rises or falls along the extension direction of the guide rail when moving.

5. The image acquisition device according to claim 2, characterized in that: The lifting assembly includes a driving member and a loading member; The driving member is fixed to the supporting assembly; The loading member is connected to the driving member and is driven to rise or fall.

6. The image acquisition device according to claim 2, characterized in that: The image acquisition device further comprises a chamfer detection unit, and the chamfer detection unit is arranged relatively to the lifting assembly along the diagonal direction of the silicon wafer group.

7. The image acquisition device according to claim 2, characterized in that: The image acquisition device also includes an in-place detection unit, which includes a first mounting column and an identification member, wherein both ends of the first mounting column are respectively connected to the support components arranged on both sides of the silicon wafer conveyor line, and the identification member is fixed to the first mounting column and the shooting direction of the identification member is located in the same plane as the silicon wafer conveyor line.

8. The image acquisition device according to claim 1, characterized in that: The image acquisition device further includes a pressing unit, which includes a lifting member, a second mounting column and a limiting member; The lifting member is arranged in the hollow part between the silicon wafer conveying lines, the bottom end of the lifting member is fixed, and the top end passes through the hollow part to lift the silicon wafer group on the silicon wafer conveying line when the lifting member is in an extended state; Both ends of the second mounting column are connected to the support components disposed on both sides of the silicon wafer conveying line; The limiting member and the lifting member are arranged on the second mounting column along the vertical direction in a direction opposite to each other, so as to cooperate with the lifting member to clamp the silicon wafer group.

9. A silicon wafer testing device, characterized in that: The silicon wafer inspection device comprises the image acquisition device according to any one of claims 1 to 8, and the silicon wafer inspection device further comprises: A control unit, used for controlling the image acquisition device to acquire a silicon wafer image and send the silicon wafer image to an image recognition unit; The image recognition unit is used to obtain the silicon wafer image and perform defect detection based on the silicon wafer image.

10. A silicon wafer detection method, characterized in that: The silicon wafer detection method comprises: The in-place detection unit obtains the position information of the silicon wafer group; The pressing unit presses the silicon wafer group based on the position information; The chamfer detection unit and the line scan detection unit move in a vertical direction to collect chamfer images and edge images of the silicon wafer group; The image recognition unit performs silicon wafer defect detection based on the chamfer box and the edge image.

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