Method and apparatus for detecting photovoltaic cells with chamfers

Abstract

The present application relates to a kind of detection method and detection equipment of photovoltaic cell with chamfer, wherein, detection method includes: photovoltaic cell is transported to optical detection station in two columns and side by side, and the two photovoltaic cells in the two columns of photovoltaic cells are symmetrically arranged with the center line between the two photovoltaic cells, and the optical camera of optical detection station is located at the center position of the two photovoltaic cells, while the optical detection is carried out to the two photovoltaic cells;After the above-mentioned optical detection is completed, one of the photovoltaic cells is rotated to the chamfer of another photovoltaic cell and is arranged in the same direction and side by side.The detection method of the present application can improve the accuracy of chromatic aberration optical detection by rotating the plane of photovoltaic cell, and can meet the demand of the same direction of photovoltaic cell chamfer in the next station, simplify the operation of production, and improve production efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic application, and in particular to a detection method and detection equipment for photovoltaic cells with chamfers. BACKGROUND

[0002] With the increasing size and decreasing thickness of solar-grade silicon wafers, the traditional whole-cell is prone to breakage in production. In order to reduce the breakage rate and follow the cost reduction trend of wafer thinning, more and more half-cell production schemes are used in the production line of solar cells, that is, the whole-cell is divided into two halves at the wafer stage to directly produce half-cell photovoltaic cells. Since the wafer cut is effectively passivated during the cell production process, the wafer cutting loss of the module is reduced.

[0003] In the color difference sorting of the half-cell test end, in order to not affect the production capacity, a scheme of testing two wafers at the same time is adopted, generally a scheme of testing both sides at the same time is adopted. Generally, in order to keep the direction of the chamfer of the cell in the grading box after sorting, the chamfers of the two cells need to be kept in the same direction during the automatic conveying process and the AOI testing process. However, in actual production, if the chamfers of the cells are kept consistent, the positions of the cameras relative to the two half-cells are different, for example, the pictures obtained by the camera are different in color under the condition that the chamfers of the two normal half-cells are kept consistent. Therefore, color mixing problems are prone to occur in production, and the half-cells with normal appearance are treated as abnormalities, causing unnecessary losses. SUMMARY

[0004] The present application provides a new detection method for photovoltaic cells with chamfers to solve the above problems.

[0005] In order to achieve the above purpose, the technical scheme provided by the present application is as follows:

[0006] A detection method for photovoltaic cells with chamfers, comprising:

[0007] The photovoltaic cells are conveyed in two rows side by side to an optical detection station. The two photovoltaic cells arranged side by side in the two rows of photovoltaic cells are symmetrically arranged with the center line between the two photovoltaic cells, and the optical camera of the optical detection station is located at the center position of the two photovoltaic cells. At the same time, optical detection is performed on the two photovoltaic cells.

[0008] After the above optical detection is completed, one of the photovoltaic cells is rotated to be arranged side by side with the chamfer of the other photovoltaic cell in the same direction.

[0009] Further, before the aforementioned two photovoltaic cells enter the optical detection station, the arrangement of the two photovoltaic cells arranged side by side is acquired, and if the two photovoltaic cells are not arranged symmetrically with respect to the center line, one of the photovoltaic cells is rotated in the plane to be arranged symmetrically with the other photovoltaic cell with respect to the center line.

[0010] Further, the test method further comprises: before the aforementioned two photovoltaic cells are subjected to optical detection at the same time, the two photovoltaic cells are subjected to positioning processing to ensure that the positions of the optical camera with respect to the two photovoltaic cells are the same.

[0011] Further, the test method further comprises: after the aforementioned one of the photovoltaic cells is rotated in the plane to be arranged with the other photovoltaic cell with the chamfer in the same direction and side by side, the photovoltaic cell that is rotated in the plane is subjected to positioning processing.

[0012] Further, the aforementioned rotation in the plane comprises:

[0013] The conveying belt conveying the photovoltaic cell is controlled to be paused;

[0014] Then, the center position of the photovoltaic cell is controlled to be adsorbed by the suction cup and rotated in the plane by a certain angle, so that the direction of the chamfer of the rotated photovoltaic cell and the relative position of the other photovoltaic cell meet the requirements of symmetry or the chamfer in the same direction;

[0015] The photovoltaic cell is controlled to be released by the suction cup on the conveying belt;

[0016] The conveying belt is controlled to resume moving.

[0017] Further, the total time of the aforementioned rotation in the plane is not greater than 1.2s.

[0018] The application also provides a detection device for a photovoltaic cell with a chamfer, wherein the detection device comprises a conveying belt for conveying two photovoltaic cells side by side at the same time, an optical camera arranged above the center line of the two conveying belts, and a first rotating unit arranged above any of the conveying belts and used for rotating the photovoltaic cell in the plane, and in the conveying direction, the first rotating unit is located at the rear side of the optical camera.

[0019] Further, the first rotating unit comprises a first rotating motor and a first suction cup electrically connected below the first rotating motor, and the vertical distance between the first suction cup and the conveying belt corresponding to the first suction cup is between 1-5mm.

[0020] Further, the detection device further comprises a first positioning unit and a second positioning unit arranged on both sides of the conveying belt to position the photovoltaic cell, the first positioning unit is located below the optical camera, and the second positioning unit is located at the rear side of the first rotating unit.

[0021] Furthermore, in the conveying direction, a second rotating unit is also included, located in front of the optical camera, and the second rotating unit is located in front of the first positioning unit.

[0022] Furthermore, it also includes a direction recognition unit for identifying the chamfer direction of photovoltaic cells, the direction recognition unit being located above the conveyor belt and in front of the second rotating unit.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: the detection method of the present invention for photovoltaic cells with chamfers ensures that the position of the optical camera relative to the two photovoltaic cells is the same during optical detection, so as to reduce unnecessary losses caused by detection errors. Then, one of the photovoltaic cells is rotated in a plane so that its chamfer direction is the same as that of the other photovoltaic cell, thereby meeting the requirement that the photovoltaic cells transported to the sorting box in the subsequent process maintain the same chamfer direction. Attached Figure Description

[0024] Figure 1 This is a flowchart of one embodiment of the detection method for photovoltaic cells with chamfered corners according to the present invention.

[0025] Figure 2 This is a flowchart of another embodiment of the detection method of the present invention.

[0026] Figure 3 This invention relates to the testing equipment implementation. Figure 1 A schematic diagram of the detection method.

[0027] Figure 4 This invention relates to the testing equipment implementation. Figure 2 A schematic diagram of the detection method.

[0028] Among them, 10-conveyor belt, 11-optical camera, 12-first rotating unit, 121-rotating motor, 122-suction cup, 13-second rotating unit, 14-direction recognition unit, 15-first positioning unit, 20-photovoltaic cell, 21-chamfer. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0030] The application provides a detection method and a detection device for photovoltaic cells with chamfers, which are used for simultaneously optically detecting the color difference of two photovoltaic cells 20, especially for half photovoltaic cells 20 with chamfers 21, and can effectively improve the accuracy of photovoltaic detection.

[0031] Specifically, the detection device of the application comprises a conveying belt 10 arranged in parallel to simultaneously convey two photovoltaic cells 20, an optical camera 11 arranged above the center line of the two conveying belts 10, a first rotating unit 12 arranged above any of the conveying belts 10 and used for planarly rotating the photovoltaic cells 20, and the first rotating unit 12 is located at the rear side of the optical camera 11 in the conveying direction. Figure 3 Figure 4 The above detection device can simultaneously optically detect two photovoltaic cells 20 with chamfers 21 arranged symmetrically with the center line, then planarly rotate one of the photovoltaic cells 20 to be in the same direction as the chamfer 21 of the other photovoltaic cell 20, so as to meet the requirement that the photovoltaic cells 20 conveyed to the grading box later have the same direction of the chamfer 21.

[0032] The optical camera 11 is arranged at an optical detection station, and when the photovoltaic cells 20 are located directly below the optical camera 11, the photovoltaic cells 20 are automatically optically detected.

[0033] Further, the detection device comprises a first positioning unit 15 arranged on both sides of the conveying belt 10 to position the photovoltaic cells 20, and the first positioning unit 15 is located below the optical camera 11 and is used for slightly adjusting the position of the photovoltaic cells 20 before optical detection, so as to ensure that the optical camera 11 has the same position relative to the two photovoltaic cells 20 and improve the accuracy of photovoltaic detection.

[0034] In actual production, the photovoltaic cells 20 waiting for optical detection on the conveying belt 10 may have the same direction of the chamfer 21 or different directions of the chamfer 21, and in order to identify the direction of the chamfer 21 of the two photovoltaic cells 20, the detection device further comprises a direction identification unit 14 used for identifying the direction of the chamfer 21 of the photovoltaic cells 20, and the direction identification unit 14 is arranged above the conveying belt 10 to facilitate simultaneous direction identification of the two photovoltaic cells 20.

[0035] If the directions of the chamfers 21 of the two photovoltaic cells 20 are arranged symmetrically with the center line, the photovoltaic cells 20 are directly conveyed to below the optical camera 11 to wait for optical detection; if the directions of the chamfers 21 of the two photovoltaic cells 20 are not arranged symmetrically with the center line, one of the photovoltaic cells 20 needs to be planarly rotated to be arranged symmetrically with the direction of the chamfer 21 of the other photovoltaic cell 20.

[0036] ​In the embodiment, in the conveying direction, the detection device further comprises a second rotating unit 13 located in front of the optical camera 11, in front of the first positioning unit, and behind the direction identification unit 14, for rotating one of the photovoltaic cells 20 in a plane to be symmetrically arranged in the chamfer direction of the other photovoltaic cell 20, and then jointly conveyed below the optical camera 11, so that the two photovoltaic cells 20 are simultaneously subjected to optical detection after being positioned by the first positioning unit 15.

[0037] In some embodiments, the detection device further comprises a third positioning unit (not shown) located behind the second rotating unit 13, the third positioning unit being located on both sides of each conveying belt 10, for performing a slight adjustment on the position of one of the photovoltaic cells 20 rotated in a plane, so as to prevent the photovoltaic cell 20 from being rotated and not being in the center of the conveying belt 10, and thus subsequently falling off the conveying belt 10, and ensure the normal conveying of the photovoltaic cell 20.

[0038] Further, the first rotating unit 12 comprises a first rotating motor 121 and a first suction disc 122 electrically connected below the first rotating motor 121, the vertical distance between the first suction disc 121 and the corresponding conveying belt 10 being 1-5 mm, so as to facilitate the control of the suction and release of the photovoltaic cell 20. The second rotating unit 13 and the first rotating unit 12 are both used to rotate the photovoltaic cell 20, and the specific structure will not be described again.

[0039] The detection device further comprises a second positioning unit (not shown) arranged on both sides of the conveying belt 10 for positioning the photovoltaic cell 20, the second positioning unit being located on both sides of any conveying belt 10, in the conveying direction, the second positioning unit being located behind the first rotating unit 12, for performing a slight adjustment on the position of the photovoltaic cell 20 rotated in a plane, so as to ensure that the photovoltaic cell 20 rotated in a plane is located in the middle position of the conveying belt 10, and ensure the smoothness of the subsequent conveying process.

[0040] In the conveying direction, the overall arrangement of the detection device of the preferred embodiment is: the direction identification unit 14, the second rotating unit 13, the third positioning unit, the first positioning unit 15, the first rotating unit 12, and the second positioning unit in sequence, and the optical camera 11 being located above the first positioning unit 15.

[0041] As can be seen from the above, based on the detection device, the application further provides a detection method of the photovoltaic cell 20 with the chamfer 21, as shown in the following steps: Figure 1As shown, the method specifically comprises: conveying the photovoltaic cells 20 into the optical detection station in two rows, and the two photovoltaic cells 20 arranged side by side are arranged symmetrically with the center line between the two photovoltaic cells 20, and the optical camera 11 of the optical detection station is located at the center position of the two photovoltaic cells 20, and the optical detection is performed on the two photovoltaic cells 20 at the same time, so as to ensure that the position of the optical camera 11 relative to the two photovoltaic cells 20 is the same, thereby avoiding optical detection errors and improving the accuracy of detection.

[0042] After the above optical detection is completed, the first rotating unit 12 is used to rotate one of the photovoltaic cells 20 in the plane to be arranged in the same direction as the chamfer 21 of the other photovoltaic cell 20, and the chamfer 21 of the two photovoltaic cells after the plane rotation is in the same direction, so that the photovoltaic cells 20 conveyed into the magazine in the subsequent process are kept in the state that the chamfers 21 are in the same direction.

[0043] The detection method of the present application is applicable to the case of the photovoltaic cells 20 made of half silicon wafers, but is not limited to the specific type, size and shape of the photovoltaic cells 20. The center line symmetric arrangement of the photovoltaic cells includes the arrangement of one side away from the chamfer adjacent to the center line and the arrangement of one side connected to the chamfer 21 adjacent to the center line, which does not affect the result of optical detection and is within the detection range of the present application. The following will be described in detail by taking the detection of two half photovoltaic cells 20 as an example.

[0044] As a preferred embodiment of the detection method of the present application, as shown in Figure 2 Before the above two rows of photovoltaic cells 20 enter the optical detection station, the direction recognition unit 14 is used to obtain the arrangement mode of the two photovoltaic cells 20 arranged side by side. If the two photovoltaic cells 20 are arranged symmetrically with the center line, the photovoltaic cells 20 are directly conveyed to the optical detection station for optical detection. If the two photovoltaic cells 20 are not arranged symmetrically with the center line, the second rotating unit 13 is used to rotate one of the photovoltaic cells 20 in the plane to be arranged symmetrically with the center line with the other photovoltaic cell 20, so as to ensure that the direction of the optical camera 11 relative to the two photovoltaic cells 20 is the same, thereby reducing unnecessary waste caused by detection errors.

[0045] Further, the plane rotation process comprises: controlling the conveying belt 10 conveying the photovoltaic cells 20 to pause; then, controlling the suction cup to adsorb the center position of the photovoltaic cell 20 and rotate the photovoltaic cell 20 in the plane by a certain angle, so that the relative position of the chamfer direction of the rotated photovoltaic cell 20 and the other photovoltaic cell 20 meets the requirement of the same direction or symmetry of the chamfer 21; controlling the suction cup to release the photovoltaic cell 20 on the conveying belt 10; and controlling the conveying belt 10 to resume moving. In this embodiment, the photovoltaic cell 20 is rotated in the plane by 180°, and the chamfers 21 of the two photovoltaic cells 20 are arranged in the same direction or symmetrically.

[0046] Specifically, before the optical detection of the two photovoltaic cells 20, the second rotating unit 13 rotates the two photovoltaic cells 20 in the plane to make the chamfers 21 of the two photovoltaic cells 20 symmetrical, so as to ensure that the optical camera 11 has the same position relative to the two photovoltaic cells 20, and improve the accuracy of the optical detection.

[0047] After the optical detection of the two photovoltaic cells 20, the first rotating unit 12 rotates the two photovoltaic cells 20 in the plane to make the chamfers 21 of the two photovoltaic cells 20 symmetrical, and in the embodiment, it is not limited to which photovoltaic cell 20 is rotated, as long as the chamfers 21 of the photovoltaic cells 20 transported to the grading box have the same direction.

[0048] Preferably, the total time of the above-mentioned rotation in the plane is not more than 1.2s, which does not affect the production capacity of the production line; in the vertical direction, the center of the suction cup is controlled to project on the center of the photovoltaic cell 20, and the error is required to be not more than 3mm, so as to realize the accurate control of the suction cup on the photovoltaic cell 20.

[0049] As another preferred embodiment of the detection method of the present application, before the optical detection of the two photovoltaic cells 20, the first positioning unit 15 is used to position the two photovoltaic cells 20. It can be understood that before the optical detection of the two photovoltaic cells 20, the photovoltaic cells 20 need to be positioned whether they are rotated in the plane or not, so as to ensure that the optical camera 11 has the same position relative to the two photovoltaic cells 20, and improve the accuracy of the optical detection.

[0050] As another preferred embodiment of the detection method of the present application, after the rotation of one of the photovoltaic cells 20 in the plane to make the chamfer 21 of the other photovoltaic cell 20 have the same direction and be arranged side by side, the second positioning unit is used to position the photovoltaic cell 20 rotated in the plane. The structure and function of the second positioning unit and the third positioning unit are the same. Since the photovoltaic cell 20 will deviate from the position of the conveying belt 10 after being rotated in the plane, and then fall off from the conveying belt 10 in the subsequent conveying process, the positioning of the photovoltaic cell 20 can effectively ensure the normal transmission of the photovoltaic cell 20 on the conveying belt 10.

[0051] In summary, the detection method of the photovoltaic cell with chamfer of the present application ensures that the optical camera 11 has the same position relative to the two photovoltaic cells 20 during the optical detection, so as to reduce unnecessary losses caused by detection errors, and then rotates one of the photovoltaic cells 20 in the plane to make the chamfer 21 of the other photovoltaic cell 20 have the same direction, so as to make the photovoltaic cells 20 transported to the grading box keep the same direction of the chamfer 21.

[0052] It should be understood that although the present specification describes each example as comprising a single independent technical solution, the specification is merely described in this way for the sake of clarity, and the skilled person should consider the specification as a whole, and the technical solutions in each example can also be appropriately combined to form other examples that the skilled person can understand.

[0053] The above detailed description of a series of embodiments is merely a specific description of the feasible embodiments of the present application, and is not intended to limit the protection scope of the present application. Any equivalent embodiments or changes made without departing from the spirit of the present application should be included in the protection scope of the present application.

Claims

1. A method for detecting photovoltaic cells with chamfers, characterized in that: photovoltaic cells are transported side by side in two rows to an optical detection station, two photovoltaic cells arranged side by side in the two rows are symmetrically arranged with a center line between the two photovoltaic cells, and an optical camera of the optical detection station is located at a center position of the two photovoltaic cells, and the two photovoltaic cells are simultaneously subjected to optical detection; the photovoltaic cells are half photovoltaic cells with chamfers; after the optical detection is completed, one of the photovoltaic cells is planarly rotated to be arranged side by side with the chamfers of the other photovoltaic cell by a first rotating unit; before the two rows of photovoltaic cells enter the optical detection station, the direction of the chamfers of the two photovoltaic cells arranged side by side is identified by a direction identifying unit, if the chamfers of the two photovoltaic cells are not symmetrically arranged with a center line, one of the photovoltaic cells is planarly rotated to be symmetrically arranged with the chamfer direction of the other photovoltaic cell with a center line by a second rotating unit.

2. The method of detecting a photovoltaic cell having a chamfered corner as defined in claim 1, wherein: Further comprising: before the two photovoltaic cells are simultaneously subjected to optical detection, the two photovoltaic cells are subjected to positioning processing to ensure that the position of the optical camera relative to the two photovoltaic cells is the same.

3. The method of detecting a photovoltaic cell having a chamfered corner as defined in claim 1, wherein: Further comprising: after the one photovoltaic cell is planarly rotated to be arranged side by side with the chamfers of the other photovoltaic cell, the planarly rotated photovoltaic cell is subjected to positioning processing.

4. The method of detecting a photovoltaic cell having a chamfered corner as defined in claim 3, wherein: The planar rotation process comprises: controlling a conveying belt conveying the photovoltaic cells to pause; then, controlling a suction cup to adsorb a center position of the photovoltaic cell and planarly rotate by a certain angle, so that the chamfer direction of the rotated photovoltaic cell and the relative position of the other photovoltaic cell meet the requirements of symmetry or same direction of the chamfers; controlling the suction cup to release the photovoltaic cell on the conveying belt; controlling the conveying belt to resume moving.

5. The method of detecting a photovoltaic cell having a chamfered corner as defined in claim 4, wherein: The total time of the planar rotation process is not more than 1.2s.

6. A testing device for photovoltaic cells with chamfered edges, characterized in that: comprising a conveying belt arranged side by side to simultaneously convey two photovoltaic cells, an optical camera arranged above the center line of the two conveying belts, a first rotating unit above either conveying belt for planarly rotating the photovoltaic cells, the first rotating unit is located at the rear side of the optical camera in the conveying direction; the detection device further comprises a second rotating unit located at the front side of the optical camera in the conveying direction, the second rotating unit is located at the front side of the first positioning unit; the detection device further comprises a direction identifying unit for identifying the direction of the chamfers of the photovoltaic cells, the direction identifying unit is located above the conveying belt and at the front side of the second rotating unit; the photovoltaic cells are half photovoltaic cells with chamfers; the detection device simultaneously subjects the two photovoltaic cells symmetrically arranged with a center line to optical detection, and after the optical detection is completed, one of the photovoltaic cells is planarly rotated to be arranged side by side with the chamfers of the other photovoltaic cell by the first rotating unit; The optical camera is arranged in an optical detection station. Before two rows of photovoltaic cells enter the optical detection station, the chamfer directions of the two photovoltaic cells arranged side by side are identified by a direction identification unit. If the chamfer directions of the two photovoltaic cells are not symmetrically arranged with the center line, one of the photovoltaic cells is rotated to be symmetrically arranged with the chamfer direction of the other photovoltaic cell with the center line by a second rotating unit.

7. The apparatus for detecting a photovoltaic cell having a chamfered corner as defined in claim 6, wherein: The first rotating unit comprises a first rotating motor and a first suction disc electrically connected below the first rotating motor. The vertical distance between the first suction disc and the corresponding conveying belt is between 1-5 mm.

8. The apparatus for detecting a photovoltaic cell having a chamfered corner as defined in claim 6, wherein: The detection device further comprises a first positioning unit and a second positioning unit arranged on both sides of the conveying belt to position the photovoltaic cells. The first positioning unit is arranged below the optical camera, and the second positioning unit is arranged on the rear side of the first rotating unit.

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