Black photovoltaic module silicon wafer color sorting method and system

Abstract

The invention discloses a black photovoltaic module silicon wafer color sorting method and system, and belongs to a method or device suitable for semiconductor processing. The color sorting method for the silicon wafers of the black photovoltaic module comprises the following steps: determining a silicon wafer polarization image about the silicon wafers to be sorted; based on color channels and polarization angles, the silicon wafer polarization image is recombined, and silicon wafer polarization sub-images about all the color channels and all the polarization angles are obtained; and determining an image mean value of the silicon wafer polarization sub-images, and performing color sorting on the silicon wafers to be sorted according to the image mean value of the silicon wafer polarization sub-images. The black photovoltaic module silicon wafer color sorting device has the beneficial effects that effective color sorting of black photovoltaic module silicon wafers can be achieved, and the color sorting accuracy is guaranteed.

Description

Technical Field

[0001] The present invention relates to a method or device suitable for semiconductor processing, and in particular to a method and system for color sorting of silicon wafers of black photovoltaic modules. Background Art

[0002] With the vigorous development of the photovoltaic industry, the market has a growing demand for aesthetics in addition to high conversion efficiency for photovoltaic modules, which has led to further demand for silicon wafer color sorting in the photovoltaic industry. At present, a photovoltaic module that appears black in the sun has been derived, which is called a black photovoltaic module in the industry. Because the silicon wafers used in the production of this module adopt a special multi-layer coating process, the silicon wafers show different color characteristics before and after being pressed into modules, which further leads to the original machine vision equipment based on silicon wafer appearance sorting (for example, patent CN207800568U battery cell color sorting defect intelligent detection equipment, publication date: August 31, 2018) cannot effectively sort its color. Summary of the invention

[0003] The technical problem to be solved by the present invention is that existing machine vision equipment cannot effectively sort the colors of black photovoltaic module silicon wafers, and a method and system for sorting the colors of black photovoltaic module silicon wafers are provided.

[0004] In order to solve the aforementioned technical problems, the present invention provides a technical solution: a method for color sorting of silicon wafers of black photovoltaic modules, which is used for color sorting of silicon wafers to be sorted. The method for color sorting of silicon wafers of black photovoltaic modules comprises: determining a silicon wafer polarization image of the silicon wafer to be sorted; reorganizing the silicon wafer polarization image based on the color channel and the polarization angle to obtain a silicon wafer polarization sub-image for each color channel and each polarization angle; and determining the image mean of the silicon wafer polarization sub-image, and color sorting the silicon wafer to be sorted according to the image mean of the silicon wafer polarization sub-image. The beneficial effect is that by analyzing the image mean of the silicon wafer polarization sub-image for each color channel and each polarization angle, effective color sorting of silicon wafers of black photovoltaic modules can be achieved, and the accuracy of color sorting can be ensured.

[0005] As a preferred solution of the method for color sorting of silicon wafers of black photovoltaic modules, the number of polarized images of silicon wafers is 2, and they are taken at different shooting angles. One polarized image of silicon wafer is directly facing the silicon wafer to be sorted, and one polarized image of silicon wafer is obliquely facing the silicon wafer to be sorted. The beneficial effect is that the color sorting result obtained by combining the polarized images of silicon wafers taken at different shooting angles has a higher accuracy.

[0006] As a preferred solution for the method of color sorting of black photovoltaic module silicon wafers, there are three color channels, namely R channel, G channel and B channel; there are four polarization angles, namely 0°, 45°, 90° and 135°; the color channels and polarization angles are arranged and combined, totaling 12 combinations.

[0007] As a preferred solution for the color sorting method of black photovoltaic module silicon wafers, different color levels for each color channel are predefined, and each color level corresponds to its own threshold range for the image mean. When the image mean of the silicon wafer polarization sub-image falls within the threshold range of one of the color levels, it is determined that the silicon wafer to be sorted is of the color level of the color channel, and color sorting is performed in this way.

[0008] As a preferred solution of the method for color sorting of silicon wafers of black photovoltaic modules, before determining the image mean of the polarization sub-image of the silicon wafer, the image uniformity of the polarization sub-image of the silicon wafer is first determined. If the image uniformity of the polarization sub-image of the silicon wafer exceeds the set threshold, it is determined that the silicon wafer to be sorted has an intra-chip color difference problem, and the color sorting is terminated. The beneficial effect is that if the silicon wafer to be sorted has an intra-chip color difference problem, it is treated as NG, and color sorting does not need to be performed again, saving sorting processing time.

[0009] In order to solve the aforementioned technical problems, the present invention also provides a black photovoltaic module silicon wafer color sorting system, which is used to perform color sorting on silicon wafers to be sorted. The black photovoltaic module silicon wafer color sorting system includes: a polarization camera, which is used to determine the silicon wafer polarization image of the silicon wafer to be sorted; and a sorting device, which is used to reorganize the silicon wafer polarization image based on the color channel and the polarization angle to obtain the silicon wafer polarization sub-image for each color channel and each polarization angle, and then determine the image mean of the silicon wafer polarization sub-image, and perform color sorting on the silicon wafer to be sorted according to the image mean of the silicon wafer polarization sub-image. The beneficial effect is that through the black photovoltaic module silicon wafer color sorting system, effective color sorting of black photovoltaic module silicon wafers can be achieved, and the accuracy of color sorting can be ensured.

[0010] As a preferred solution for the color sorting system of silicon wafers of black photovoltaic modules, the polarization camera includes: a first polarization camera and a second polarization camera. When color sorting the silicon wafers to be sorted, the first polarization camera is directly opposite to the silicon wafers to be sorted, and the second polarization camera is obliquely opposite to the silicon wafers to be sorted. Specifically, the first polarization camera is directly above the center point of the silicon wafer to be sorted, the first polarization camera points to the center point of the silicon wafer to be sorted, and the camera focus of the first polarization camera is at the center point of the silicon wafer to be sorted; the second polarization camera is directly above one of the diagonals of the silicon wafer to be sorted, the second polarization camera points to the center point of the silicon wafer to be sorted, and the camera focus of the second polarization camera is at the center point of the silicon wafer to be sorted. The beneficial effect is that the color sorting result obtained by combining the polarization images of the silicon wafers at different shooting angles has higher accuracy.

[0011] In addition to the technical problems solved by the present invention, the technical features that constitute the technical solution, and the beneficial effects brought about by the technical features of the technical solution described above, other technical problems that can be solved by the present invention, other technical features included in the technical solution, and the beneficial effects brought about by these technical features will be further described in detail in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a method flow chart of an embodiment of the method for color sorting of black photovoltaic module silicon wafers of the present invention.

[0013] Figure 2 Schematic diagram of color superpixels of an image captured by a polarization camera in an embodiment of the method for color sorting of silicon wafers of black photovoltaic modules of the present invention. The four squares in the upper left corner are red R. The four squares in the lower right corner are blue B. The four squares in the lower left corner and the upper right corner are green G.

[0014] Figure 3 It is a structural schematic diagram of an embodiment of a black photovoltaic module silicon wafer color sorting system of the present invention. DETAILED DESCRIPTION

[0015] The present invention is further described in detail below by means of specific embodiments in combination with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0016] See also Figure 1 , the figure shows a method for color sorting of silicon wafers of black photovoltaic modules. The method for color sorting of silicon wafers of black photovoltaic modules is to use machine vision detection technology to color sort the silicon wafers to be sorted. The method for color sorting of silicon wafers of black photovoltaic modules includes: Step S1, determining a polarization image of the silicon wafer to be sorted. In a specific implementation, the silicon wafer to be sorted is photographed by a polarization camera. Figure 2 , the figure shows the color superpixels of the image captured by the polarization camera. There are 3 color channels, namely R channel, G channel and B channel. There are 4 polarization angles, namely 0°, 45°, 90° and 135°.

[0017] Step S2, based on the color channel and the polarization angle, the silicon wafer polarization image is reorganized to obtain the silicon wafer polarization sub-images for each color channel and each polarization angle. In the specific implementation, each color channel and each polarization angle are arranged and combined, with a total of 12 combinations. That is, one silicon wafer polarization image can be reorganized into 12 silicon wafer polarization sub-images. The 12 silicon wafer polarization sub-images are respectively the polarization angle 0° image of the R channel, the polarization angle 45° image of the R channel, the polarization angle 90° image of the R channel, the polarization angle 135° image of the R channel, the polarization angle 0° image of the G channel, the polarization angle 45° image of the G channel, the polarization angle 90° image of the G channel, the polarization angle 135° image of the G channel, the polarization angle 0° image of the B channel, the polarization angle 45° image of the B channel, the polarization angle 90° image of the B channel, and the polarization angle 135° image of the B channel.

[0018] Step S3, determining the image uniformity of the silicon wafer polarization sub-image. If the image uniformity of the silicon wafer polarization sub-image exceeds the set threshold, it is determined that the silicon wafer to be sorted has an intra-chip chromatic aberration problem, and the color sorting is terminated. At this time, the silicon wafer to be sorted can be treated as NG. In specific implementation, traverse the 12 silicon wafer polarization sub-images, and perform the above operation on each of the silicon wafer polarization sub-images.

[0019] Step S4, determine the image mean of the polarization sub-image of the silicon wafer. Perform color sorting on the silicon wafer to be sorted according to the image mean of the polarization sub-image of the silicon wafer. In a specific implementation, traverse the 12 polarization sub-images of the silicon wafer, and perform the above-mentioned operation on each polarization sub-image of the silicon wafer. In a specific implementation, predefine different color levels for each color channel. Each color level corresponds to its own threshold range for the image mean. When the image mean of the polarization sub-image of the silicon wafer falls within the threshold range of one of the color levels, it is determined that the silicon wafer to be sorted is the color level of the color channel, and color sorting is performed accordingly.

[0020] It should be noted that the number of polarized images of the silicon wafer is not limited to one. Preferably, the number of polarized images of the silicon wafer is two, and they are taken at different angles. In specific implementation, one image is directly facing the silicon wafer to be sorted, and the other image is obliquely facing the silicon wafer to be sorted. The purpose of such a design is to combine the polarized images of the silicon wafer at different shooting angles, and the color sorting result obtained has a higher accuracy.

[0021] See also Figure 3 , the figure shows a black photovoltaic module silicon wafer color sorting system. The black photovoltaic module silicon wafer color sorting system is used to implement the black photovoltaic module silicon wafer color sorting method. The black photovoltaic module silicon wafer color sorting system includes: a first polarization camera 1, a first camera light source 2, a second polarization camera 3, a second camera light source 4 and a sorting device (omitted in the figure), etc. When color sorting the silicon wafer 100 to be sorted, the first polarization camera 1, the first camera light source 2, the second polarization camera 3 and the second camera light source 4 are configured as follows: the first polarization camera 1 is directly opposite to the silicon wafer 100 to be sorted, and the light emitted by the first camera light source 2 is reflected to the first polarization camera 1 through the silicon wafer 100 to be sorted; the second polarization camera 3 is obliquely opposite to the silicon wafer 100 to be sorted, and the light emitted by the second camera light source 4 is reflected to the second polarization camera 3 through the silicon wafer 100 to be sorted.

[0022] The first polarization camera 1 is used to obtain the polarization sub-image of the silicon wafer facing the to-be-sorted silicon wafer 100. The second polarization camera 3 is used to obtain the polarization sub-image of the silicon wafer facing obliquely the to-be-sorted silicon wafer 100.

[0023] In a specific implementation, the first polarization camera 1 is directly above the center point of the silicon wafer to be sorted 100. The first polarization camera 1 points to the center point of the silicon wafer to be sorted 100. The camera focus of the first polarization camera 1 is at the center point of the silicon wafer to be sorted 100.

[0024] In a specific implementation, the second polarization camera 3 is directly above one of the diagonals of the silicon wafer 100 to be sorted. The second polarization camera 3 is not directly above the center point of the silicon wafer 100 to be sorted. The second polarization camera 3 points to the center point of the silicon wafer 100 to be sorted. The camera focus of the second polarization camera 3 is at the center point of the silicon wafer 100 to be sorted. The second camera light source 4 is also directly above one of the diagonals of the silicon wafer 100 to be sorted. The second camera light source 4 is also not directly above the center point of the silicon wafer 100 to be sorted. The second camera light source 4 points to the center point of the silicon wafer 100 to be sorted. More specifically, the pitch angles of the second polarization camera 3 and the second camera light source 4 are +45° and -45°.

[0025] The sorting device is used to reorganize the silicon wafer polarization image based on the color channel and the polarization angle to obtain the silicon wafer polarization sub-image for each color channel and each polarization angle, then determine the image mean of the silicon wafer polarization sub-image, and perform color sorting on the silicon wafer to be sorted according to the image mean of the silicon wafer polarization sub-image.

[0026] The above only expresses the implementation mode of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A method for color sorting of silicon wafers of black photovoltaic modules, used for color sorting of silicon wafers to be sorted, characterized in that: include: Determining a silicon wafer polarization image of the silicon wafer to be sorted; Based on the color channels and polarization angles, the silicon wafer polarization images are reorganized to obtain silicon wafer polarization sub-images for each color channel and each polarization angle; and, An image mean value of the polarization sub-image of the silicon wafer is determined, and the silicon wafer to be sorted is color sorted according to the image mean value of the polarization sub-image of the silicon wafer.

2. The method for color sorting of black photovoltaic module silicon wafers according to claim 1, characterized in that: The number of the silicon wafer polarization images is 2, and they are taken at different angles.

3. The method for color sorting of black photovoltaic module silicon wafers according to claim 2, characterized in that: One of the polarized images of the silicon wafer is directly opposite to the silicon wafer to be sorted, and another of the polarized images of the silicon wafer is obliquely opposite to the silicon wafer to be sorted.

4. The method for color sorting of black photovoltaic module silicon wafers according to claim 1, characterized in that: There are three color channels, namely R channel, G channel and B channel; there are four polarization angles, namely 0°, 45°, 90° and 135°; the color channels and polarization angles are arranged and combined, with a total of 12 combinations.

5. The method for color sorting of black photovoltaic module silicon wafers according to claim 4, characterized in that: Different color levels for each color channel are predefined, and each color level corresponds to its own threshold range for the image mean. When the image mean of the silicon wafer polarization sub-image falls within the threshold range of one of the color levels, it is determined that the silicon wafer to be sorted is of the color level of the color channel, so that color sorting is performed.

6. The method for color sorting of black photovoltaic module silicon wafers according to claim 1, characterized in that: Before determining the image mean of the silicon wafer polarization sub-image, the image uniformity of the silicon wafer polarization sub-image is first determined. If the image uniformity of the silicon wafer polarization sub-image exceeds a set threshold, it is determined that the silicon wafer to be sorted has an intra-wafer color difference problem, and color sorting is terminated.

7. A black photovoltaic module silicon wafer color sorting system, used for color sorting of silicon wafers to be sorted, characterized in that: include: A polarization camera, used for determining a polarization image of the silicon wafer to be sorted; as well as, The sorting device is used to reorganize the silicon wafer polarization image based on the color channel and the polarization angle to obtain the silicon wafer polarization sub-image about each color channel and each polarization angle, then determine the image mean of the silicon wafer polarization sub-image, and color sort the silicon wafer to be sorted according to the image mean of the silicon wafer polarization sub-image.

8. The black photovoltaic module silicon wafer color sorting system according to claim 7, characterized in that: The polarization camera includes: a first polarization camera and a second polarization camera. When the silicon wafers to be sorted are color sorted, the first polarization camera is directly opposite to the silicon wafers to be sorted, and the second polarization camera is obliquely opposite to the silicon wafers to be sorted.

9. The black photovoltaic module silicon wafer color sorting system according to claim 8, characterized in that: The first polarization camera is directly above the center point of the silicon wafer to be sorted, the first polarization camera points to the center point of the silicon wafer to be sorted, and the camera focus of the first polarization camera is at the center point of the silicon wafer to be sorted; the second polarization camera is directly above one of the diagonals of the silicon wafer to be sorted, the second polarization camera points to the center point of the silicon wafer to be sorted, and the camera focus of the second polarization camera is at the center point of the silicon wafer to be sorted.

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