Crystalline silicon solar cell, laser sintering pattern, processing method and related equipment

Abstract

The invention provides a crystalline silicon solar cell, a laser sintering pattern, a processing method and related equipment, and relates to the technical field of solar cells. According to the method, redundant laser sintering coverage space is provided for the crystalline silicon solar cell through the laser sintering pattern, so that the corresponding crystalline silicon solar cell can be sintered to the maximum extent, and the problem of edge blackening of the corresponding EL test image is effectively solved; meanwhile, the laser sintering pattern can also ensure that the middle area of the crystalline silicon solar cell is subjected to two times of laser scanning processing, so that carriers corresponding to the middle area are fully excited to form enough metal silicon contact points, the problem of pocking marks or blackening in the middle of an image corresponding to an EL test image is effectively solved, and the performance of the solar cell is improved. Therefore, on the basis that the metal contact resistance of the corresponding solar cell is effectively reduced by using the laser-induced sintering technology, the photoelectric conversion efficiency and the cell production yield of the corresponding solar cell are effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a crystalline silicon solar cell, a laser sintering pattern and processing method, and related equipment. Background Art

[0002] At present, the main metallization method of conventional crystalline silicon solar cells (for example, TOPCon (Tunnel Oxide Passivated Contact) solar cells, PERT (Passivated Emitter and Rear Totally-diffused cell) solar cells, PERC (Passivated Emitter and Rear Cell) solar cells, IBC (Interdigitated Back Contact) solar cells, etc.) is: screen printing metal grid lines on the cell substrate of the crystalline silicon solar cell, and then sending them into a sintering furnace for high-temperature sintering, so that the metal grid lines form ohmic contact with silicon after high-temperature sintering, so as to realize the collection and output of photogenerated carriers. It is worth noting that the traditional sintering furnace cannot ensure the formation of good ohmic contact with the corresponding crystalline silicon solar cell, and cannot achieve good photoelectric conversion efficiency. It is very easy to produce serious metal contact composite losses, and there is an obvious problem of battery production yield.

[0003] To this end, the industry has further studied the metal contact mechanism and proposed a laser-induced sintering (LIF) technology to replace the original sintering method to improve the metal contact composite loss of the corresponding crystalline silicon solar cells. However, in the actual use of the laser-induced sintering technology, there are still many technical problems that need to be solved, such as the black edge problem and / or the pitting or blackening problem in the middle of the image in the EL (Electroluminescence) test image of the corresponding solar cell after the introduction of the laser-induced sintering technology. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide a crystalline silicon solar cell and its laser sintering pattern, a laser sintering pattern planning method, a laser sintering control method, a photovoltaic module, a laser induced sintering device and a readable storage medium, which can provide a redundant laser sintering coverage space for the crystalline silicon solar cell through the provided laser sintering pattern, so that the corresponding crystalline silicon solar cell can be sintered to the maximum extent, so as to effectively improve the edge blackening problem of the corresponding EL test image. At the same time, through the laser sintering pattern, it is ensured that the middle area of ​​the corresponding crystalline silicon solar cell can be processed by laser scanning twice, so that the carriers in the middle area can be fully excited to form a sufficient number of metal silicon contact points, so as to effectively improve the image pitting or blackening problem in the middle of the corresponding EL test image, thereby effectively improving the photoelectric conversion efficiency and battery production yield of the corresponding solar cell on the basis of effectively reducing the metal contact resistance of the corresponding solar cell by using the laser induced sintering technology.

[0005] In order to achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0006] In a first aspect, the present application provides a laser sintering pattern of a crystalline silicon solar cell, wherein the pattern size of the laser sintering pattern is larger than the layout size of the crystalline silicon solar cell, and the laser sintering pattern comprises a plurality of first sintering path lines and a plurality of second sintering path lines which are parallel to the extension direction of the length of the battery grid lines of the crystalline silicon solar cell and are spaced apart from each other, wherein one line endpoint of each of the plurality of first sintering path lines is located on a first pattern boundary of the laser sintering pattern, one line endpoint of each of the plurality of second sintering path lines is located on a second pattern boundary of the laser sintering pattern, and the first pattern boundary is arranged opposite to the second pattern boundary;

[0007] Each first sintering path line corresponds to a second sintering path line individually, and the corresponding first sintering path lines and second sintering path lines partially overlap in the extension direction of the battery grid line length, wherein the corresponding first sintering path lines and second sintering path lines are used to realize laser scanning sintering of the same battery cell grid line.

[0008] In an optional embodiment, among the plurality of first sintering path lines intersecting with the theoretically normalized distribution area, the actual spacing between two adjacent first sintering path lines is consistent with the spacing between the cell grid lines of the crystalline silicon solar cell, wherein the theoretically normalized distribution area is used to represent the actual mapping area of ​​the theoretical distribution position of the crystalline silicon solar cell after normalization within the laser sintering pattern;

[0009] Among the plurality of second sintering path lines intersecting the theoretical normalized distribution area, the actual spacing between two adjacent second sintering path lines is consistent with the battery grid line spacing.

[0010] In an optional embodiment, among the plurality of first sintering path lines that do not intersect the theoretical normalized distribution area, the actual spacing between two adjacent first sintering path lines is smaller than the battery grid line spacing;

[0011] Among the plurality of second sintering path lines that do not intersect the theoretical normalized distribution area, the actual spacing between two adjacent second sintering path lines is smaller than the battery grid line spacing.

[0012] In an optional embodiment, the other line endpoint of each first sintering path line is located at the edge of the first middle area of ​​the crystalline silicon solar cell on the theoretical normalized mapping straight line within the laser sintering pattern, and the other line endpoint of each second sintering path line is located at the edge of the second middle area of ​​the crystalline silicon solar cell on the theoretical normalized mapping straight line within the laser sintering pattern, wherein the edge of the first middle area and the edge of the second middle area are parallel to each other and perpendicular to the extension direction of the battery grid line length, the theoretical normalized mapping straight line of the edge of the first middle area is close to the boundary of the second figure, and the theoretical normalized mapping straight line of the edge of the second middle area is close to the boundary of the first figure.

[0013] In an optional embodiment, the first sintering path lines and the second sintering path lines corresponding to each other are staggered in the laser sintering pattern.

[0014] In a second aspect, the present application provides a laser sintering pattern planning method, the method comprising:

[0015] Obtaining the layout size, cell grid line length and cell grid line spacing of the crystalline silicon solar cell to be sintered;

[0016] In a laser sintering plane of a laser induced sintering device, a target laser sintering area that can cover the normalized crystalline silicon solar cell is determined according to the layout size, wherein the area size of the target laser sintering area is larger than the layout size;

[0017] According to the battery grid line spacing and the battery grid line length, sintering path line planning is performed in the target laser sintering area to obtain a plurality of first sintering path lines and a plurality of second sintering path lines that are parallel to the battery grid line length extension direction of the crystalline silicon solar cell and spaced from each other, so as to form a laser sintering pattern matching the crystalline silicon solar cell, wherein each first sintering path line corresponds to a second sintering path line individually, and each of the corresponding first sintering path line and the corresponding second sintering path line has a path line endpoint located on the opposite side of the target laser sintering area, and the corresponding first sintering path line and the second sintering path line partially overlap in projection in the battery grid line length extension direction, wherein the corresponding first sintering path line and the second sintering path line cooperate to realize laser scanning sintering of the same battery cell grid line.

[0018] In an optional embodiment, the step of planning a sintering path line in the target laser sintering area according to the cell grid line spacing and the cell grid line length to obtain a plurality of first sintering path lines and a plurality of second sintering path lines that are parallel to the extension direction of the cell grid line length of the crystalline silicon solar cell and spaced from each other comprises:

[0019] On a first side of the target laser sintering area perpendicular to the extending direction of the battery grid line length, a plurality of first path line endpoints are determined according to the battery grid line spacing, and on a second side of the target laser sintering area opposite to the first side, a plurality of second path line endpoints are determined according to the battery grid line spacing;

[0020] For each target path line endpoint among the plurality of first path line endpoints and the plurality of second path line endpoints, determining a desired path line endpoint corresponding to the target path line endpoint according to the battery grid line length along the extending direction of the battery grid line length, wherein the desired path line endpoint is located on a straight line along the edge of a middle area of ​​the crystalline silicon solar cell away from the target path line endpoint;

[0021] A sintering path line is planned between the target path line endpoint and the desired path line endpoint corresponding to the target path line endpoint to obtain a first sintering path line or a second sintering path line.

[0022] In an optional embodiment, the step of determining a plurality of first path line endpoints or second path line endpoints on the target edge of the target laser sintering area according to the battery grid line spacing includes:

[0023] Determine a normalized projection line segment of the crystalline silicon solar cell on the target edge along the extending direction of the battery grid line, wherein the target edge is a first edge matching the endpoint of the first path line, or the target edge is a second edge matching the endpoint of the second path line;

[0024] Selecting a plurality of first discrete points in the normalized projection line segment according to the battery grid line spacing, and using each selected first discrete point as a first path line endpoint or a second path line endpoint, wherein the distance between two adjacent first discrete points is consistent with the battery grid line spacing;

[0025] A plurality of second discrete points are selected according to the target spacing in the remaining line segments of the target edge except the normalized projection line segment, and each selected second discrete point is used as a first path line endpoint or a second path line endpoint, wherein the distance between two adjacent second discrete points is consistent with the target spacing, and the target spacing is obtained by multiplying the battery grid line spacing by a preset spacing coefficient, and the preset spacing coefficient is a positive number less than 1.

[0026] In an optional embodiment, the step of determining the desired path line endpoint corresponding to the target path line endpoint according to the battery grid line length along the extending direction of the battery grid line length includes:

[0027] Calculating a first distance between an edge of a target middle region corresponding to an endpoint of the target path line and an edge of a target cell in the crystalline silicon solar cell according to an area ratio of the middle region of the crystalline silicon solar cell and a length of the cell grid line, wherein the edge of the target middle region is distributed away from the endpoint of the target path line, and the edge of the target cell is distributed close to the endpoint of the target path line;

[0028] Calculating a second distance from an endpoint of the target path line to an edge of the target cell according to a relative normalized position relationship between the crystalline silicon solar cell and the target laser sintering area;

[0029] A desired path line endpoint matching the target path line endpoint is determined in the target laser sintering area along the battery grid line length extension direction, wherein the distance between the desired path line endpoint and the target path line endpoint is obtained by adding the first distance and the second distance.

[0030] In an optional embodiment, the first distance between the edge of the target middle area corresponding to the endpoint of the target path line and the edge of the target cell is calculated using the following formula:

[0031]

[0032] Wherein, d1 is used to represent the first distance, p is used to represent the area ratio of the middle region, and l is used to represent the length of the battery grid line.

[0033] In an optional embodiment, the first sintering path lines and the second sintering path lines corresponding to each other are staggered in the target laser sintering area.

[0034] In a third aspect, the present application provides a laser sintering control method, which is applied to a laser induced sintering device, and the method comprises:

[0035] Acquire a laser sintering pattern as described in any one of the preceding embodiments that matches the crystalline silicon solar cell wafer normalized in the laser sintering plane, wherein the laser sintering pattern is planned using the laser sintering pattern planning method as described in any one of the preceding embodiments;

[0036] A reverse bias voltage is applied to the crystalline silicon solar cell, and the laser component is driven to perform laser scanning according to a plurality of first sintering path lines in the laser sintering pattern, and then the laser component is driven to perform laser scanning and irradiation according to a plurality of second sintering path lines in the laser sintering pattern, so as to sinter all battery grid lines that need to be sintered in the crystalline silicon solar cell.

[0037] In an optional embodiment, the diameter range of the circular laser spot or the side length range of the square laser spot of the laser assembly on the crystalline silicon solar cell is 90-120 μm.

[0038] In a fourth aspect, the present application provides a crystalline silicon solar cell, comprising a cell substrate, and a plurality of cell grid lines screen-printed on the cell substrate, wherein each cell grid line is laser scanned and sintered based on the laser sintering pattern described in any one of the aforementioned embodiments.

[0039] In a fifth aspect, the present application provides a photovoltaic module, comprising a plurality of crystalline silicon solar cells as described in the foregoing embodiments, wherein the plurality of crystalline silicon solar cells are arranged in an array.

[0040] In a sixth aspect, the present application provides a laser induced sintering device, the device comprising a cell carrier, a laser assembly, a reverse voltage applying unit and a main control unit, wherein the cell carrier is used to carry a crystalline silicon solar cell, the main control unit is electrically connected to the laser assembly and the reverse voltage applying unit respectively, the laser assembly is used to perform laser scanning and irradiation on the crystalline silicon solar cell carried on the cell carrier, and the reverse voltage applying unit is used to apply a reverse bias voltage to the crystalline silicon solar cell;

[0041] The main control unit stores a computer program, and by running the computer program, implements the laser sintering pattern planning method described in any one of the aforementioned embodiments, or drives the laser component and the reverse voltage application unit to collaboratively implement the laser sintering control method described in any one of the aforementioned embodiments.

[0042] In a seventh aspect, the present application provides a readable storage medium having a computer program stored thereon. When the computer program is executed by a laser induced sintering device, it implements the laser sintering graphic planning method described in any one of the aforementioned embodiments or the laser sintering control method described in any one of the aforementioned embodiments.

[0043] In this case, the beneficial effects of the embodiments of the present application may include the following:

[0044] The graphic size of the laser sintering pattern provided by the present application for the crystalline silicon solar cell is larger than the layout size of the crystalline silicon solar cell, so that the complete laser sintering area corresponding to the laser induced sintering equipment of the laser sintering pattern can fully cover the corrected crystalline silicon solar cell, and at the same time, the laser sintering pattern includes a plurality of first sintering path lines and a plurality of second sintering path lines which are parallel to the extension direction of the battery grid line length of the crystalline silicon solar cell and are spaced apart from each other, wherein one line endpoint of each of the plurality of first sintering path lines is on the first graphic boundary of the laser sintering pattern, and one line endpoint of each of the plurality of second sintering path lines is on the second graphic boundary of the laser sintering pattern which is arranged opposite to the first graphic boundary. At this time, each first sintering path line will correspond to a second sintering path line separately, and the first sintering path lines and the second sintering path lines which correspond to each other are parallel to the battery grid line length. The projections partially overlap in the extension direction, so that the first sintering path line and the second sintering path line corresponding to each other can cooperatively realize the laser scanning sintering of the same cell grid line, thereby ensuring that the laser sintering pattern can provide redundant laser sintering coverage space for the crystalline silicon solar cell, ensuring that the corresponding crystalline silicon solar cell can be sintered to the maximum extent, to improve the edge blackening problem of the corresponding EL test image, and at the same time, the laser sintering pattern can also ensure that the middle area of ​​the crystalline silicon solar cell is laser scanned twice, so that the carriers in the corresponding middle area are fully excited and form a sufficient number of metal silicon contact points, to improve the image pitting or blackening problem in the middle of the corresponding EL test image, and then on the basis of effectively reducing the metal contact resistance of the corresponding solar cell by using the laser induced sintering technology, the photoelectric conversion efficiency of the corresponding solar cell and the battery production yield are effectively improved.

[0045] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 A schematic diagram of the composition of a laser induced sintering device provided in an embodiment of the present application;

[0048] Figure 2 A schematic diagram of a process flow of a laser sintering pattern planning method provided in an embodiment of the present application;

[0049] Figure 3 A schematic diagram of the distribution of the laser sintering pattern and the crystalline silicon solar cell provided in the embodiment of the present application within the laser sintering plane of the laser induced sintering equipment;

[0050] Figure 4 for Figure 2 A schematic flow chart of the sub-steps included in step S230;

[0051] Figure 5 for Figure 4 A schematic diagram of the path line endpoint distribution of sub-step S231 in FIG.

[0052] Figure 6 for Figure 4 A schematic diagram of the path line endpoint distribution of sub-step S232;

[0053] Figure 7 A schematic diagram of a laser sintering pattern provided for a crystalline silicon solar cell in an embodiment of the present application;

[0054] Figure 8 A schematic flow chart of the laser sintering control method provided in an embodiment of the present application.

[0055] Icons: 10-laser induced sintering equipment; 11-main control unit; 12-laser assembly; 13-reverse voltage application unit; 14-cell carrier. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0057] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0058] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0059] In the description of the present application, it should be understood that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the application is conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0060] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0061] In addition, in the description of the present application, it is understood that the relational terms such as the term "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements that are not clearly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the sentence "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood by specific circumstances.

[0062] The applicant has found through in-depth research on the laser induced sintering technology that in actual application, the laser induced sintering technology is often unable to perform laser irradiation sintering on the metal grid lines (e.g., silver grid lines) located at the edge of the crystalline silicon solar cell (e.g., N-type TOPCon solar cell) due to factors such as cell alignment offset and silicon wafer size exceeding the preset size, resulting in the problem of black edges in the EL test image of the corresponding crystalline silicon solar cell; in addition, for conventional crystalline silicon solar cells, the carrier excitation energy requirement of the metal grid lines in the middle area of ​​the cell is much higher than the carrier excitation energy in other areas. The conventional laser induced sintering technology (i.e., one-time laser irradiation and sintering of each metal grid line in the entire crystalline silicon solar cell according to a specific carrier excitation energy) is actually prone to insufficient carrier excitation in the middle area of ​​the corresponding crystalline silicon solar cell, and it is impossible to form sufficient metal silicon contact points, resulting in a larger contact resistivity in the middle area of ​​the crystalline silicon solar cell than in other areas, and a higher corresponding square resistance than in other areas, which in turn causes the EL test image of the corresponding crystalline silicon solar cell to have pitting or blackening in the middle of the image, seriously affecting the photoelectric conversion efficiency of the crystalline silicon solar cell and the battery production yield.

[0063] To this end, the embodiments of the present application solve the above-mentioned problems by providing a crystalline silicon solar cell and its laser sintering pattern, a laser sintering pattern planning method, a laser sintering control method, a photovoltaic module, a laser induced sintering device and a readable storage medium, so as to effectively improve the edge blackening problem and the pitting or blackening problem in the middle of the image in the EL test image of the crystalline silicon solar cell through the provided laser sintering pattern, thereby effectively improving the photoelectric conversion efficiency and battery production yield of the corresponding crystalline silicon solar cell on the basis of effectively reducing the metal contact resistance of the corresponding crystalline silicon solar cell by using the laser induced sintering technology.

[0064] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0065] Please refer to Figure 1 , Figure 1: is a schematic diagram of the composition of the laser induced sintering device 10 provided in the embodiment of the present application. In the embodiment of the present application, the laser induced sintering device 10 may include a main control unit 11, a laser assembly 12, a reverse voltage application unit 13 and a cell carrier 14, wherein the cell carrier 14 is used to carry a crystalline silicon solar cell and provide an effective laser sintering operation plane (i.e., a laser sintering plane) for all cell grid lines that need to be sintered in the crystalline silicon solar cell; the cell type of the crystalline silicon solar cell may be, but not limited to, a TOPCon solar cell, a PERT solar cell, a PERC solar cell, an IBC solar cell, etc.; each cell grid line on the crystalline silicon solar cell may be formed by silver paste screen printing.

[0066] In this embodiment, the main control unit 11 is electrically connected to the laser assembly 12 and the reverse voltage applying unit 13 respectively, the laser assembly 12 is used to perform laser scanning and irradiation on the crystalline silicon solar cell carried on the cell carrier 14, and the reverse voltage applying unit 13 is used to apply a reverse bias voltage to the crystalline silicon solar cell, wherein the main control unit 11 can drive the laser assembly 12 and the reverse voltage applying unit 13 to collaboratively perform laser scanning and sintering on the crystalline silicon solar cell by controlling their respective working states.

[0067] Among them, for any battery grid line that needs to be sintered in the crystalline silicon solar cell, the local part of the battery grid line irradiated by the laser beam will form induced carriers due to the laser beam, and form a local current under the influence of the reverse bias voltage. At this time, because the preferred transmission path of the local current is a low-resistance path, the corresponding local current will automatically seek a low-resistance position for aggregation, resulting in a high-temperature heating point at the corresponding low-resistance position due to the high current density phenomenon, so that the low-resistance position is sintered under the action of high temperature, triggering the mutual diffusion of silver and silicon at the low-resistance position, thereby forming a silver-silicon alloy junction (i.e., a metal silicon contact point) at the low-resistance position.

[0068] Optionally, in the present embodiment, the main control unit 11 pre-stores a specific computer program related to the laser sintering pattern planning operation, and plans an adaptive laser sintering pattern for the crystalline silicon solar cell by running the specific computer program, ensuring that the planned laser sintering pattern can provide a redundant laser sintering coverage space for the crystalline silicon solar cell, ensuring that the corresponding crystalline silicon solar cell can be sintered to the maximum extent, so as to effectively improve the blackening problem of the edge of the corresponding EL test image. At the same time, the planned laser sintering pattern can also ensure that the middle area of ​​the corresponding crystalline silicon solar cell is laser scanned twice, so that the carriers in the corresponding middle area are fully excited to form a sufficient number of metal silicon contact points, so as to effectively improve the pitting or blackening problem in the middle of the corresponding EL test image, thereby effectively improving the photoelectric conversion efficiency and battery production yield of the corresponding solar cell on the basis of effectively reducing the metal contact resistance of the corresponding solar cell by using the laser induced sintering technology.

[0069] Optionally, in this embodiment, the main control unit 11 also pre-stores a specific computer program related to the laser induced sintering control operation, and by running the specific computer program, drives the laser assembly 12 and the reverse voltage applying unit 13 to collaboratively perform laser scanning and sintering according to a laser sintering pattern adapted to the crystalline silicon solar cell, so as to improve the edge blackening problem and the pitting or blackening problem in the middle of the image in the EL test image of the corresponding crystalline silicon solar cell after the introduction of the laser induced sintering technology, thereby effectively improving the photoelectric conversion efficiency and battery production yield of the corresponding crystalline silicon solar cell on the basis of effectively reducing the metal contact resistance of the corresponding crystalline silicon solar cell by utilizing the laser induced sintering technology.

[0070] Understandably, Figure 1 The block diagram shown is only a schematic diagram of a composition of the laser induced sintering device 10. The laser induced sintering device 10 may also include Figure 1 More or fewer components as shown, or with Figure 1 Different configurations shown. Figure 1 Each component shown in the figure can be implemented by hardware, software or a combination thereof.

[0071] In the present application, in order to ensure that the above-mentioned laser induced sintering equipment 10 can plan an adaptive laser sintering pattern for the crystalline silicon solar cell, and effectively improve the edge blackening problem of the EL test image and the pitting or blackening problem in the middle of the image through the planned laser sintering pattern, so as to effectively improve the photoelectric conversion efficiency of the crystalline silicon solar cell and the battery production yield, the embodiment of the present application provides a laser sintering pattern planning method to achieve the above-mentioned purpose. The laser sintering pattern planning method provided by the present application is described in detail below.

[0072] Please refer to Figure 2 , Figure 2 : is a schematic diagram of the process of the laser sintering pattern planning method provided in the embodiment of the present application. In the embodiment of the present application, Figure 2 The laser sintering pattern planning method shown may include steps S210 to S230.

[0073] Step S210, obtaining the layout size, cell grid line length and cell grid line spacing of the crystalline silicon solar cell.

[0074] In this embodiment, the layout size is used to describe the default layout size of the crystalline silicon solar cell, and the layout size includes the cell length and cell width of the crystalline silicon solar cell; the cell grid line length is used to describe the actual length of any cell grid line that needs to be sintered in the crystalline silicon solar cell, and the cell grid line spacing is used to describe the actual distance between two adjacent cell grid lines in the crystalline silicon solar cell; the cell grid line length extension directions of all the cell grid lines in the crystalline silicon solar cell are parallel to each other.

[0075] Step S220, determining a target laser sintering area that can cover the normalized crystalline silicon solar cell according to the layout size within the laser sintering plane of the laser induced sintering equipment.

[0076] In this embodiment, after the laser induced sintering equipment 10 obtains the relevant parameter data of the crystalline silicon solar cell (including the above-mentioned layout size, battery grid line length and battery grid line spacing), it will determine the theoretical distribution position of the corresponding crystalline silicon solar cell after correction in the laser sintering plane (including the theoretical position of the four battery cell edges of the corresponding crystalline silicon solar cell in the battery cell correction state) and the theoretical distribution position of each battery grid line in the crystalline silicon solar cell after the battery cell is corrected based on the pre-stored default correction reference position of the battery cell center of the crystalline silicon solar cell of different battery cell types in the laser sintering plane of the battery cell support platform 14 according to the aforementioned relevant parameter data, and then construct and delineate the target laser sintering area that can effectively cover the corrected crystalline silicon solar cell in the laser sintering plane (see Figure 3 The larger rectangular dotted line frame area in the figure) is used to provide redundant laser sintering coverage space for the crystalline silicon solar cell through the target laser sintering area, thereby reducing the influence of factors such as cell correction offset and silicon wafer size exceeding the preset size on the sintering result of the solar cell, ensuring that the corresponding crystalline silicon solar cell can be sintered to the maximum extent, thereby effectively improving the edge blackening problem of the corresponding EL test image.

[0077] In this process, the area size of the target laser sintering area is larger than the layout size of the crystalline silicon solar cell to be sintered. For example, the area length of the target laser sintering area is larger than the cell length of the corresponding crystalline silicon solar cell, and / or the area width of the target laser sintering area is larger than the cell width of the corresponding crystalline silicon solar cell.

[0078] In one implementation of the present embodiment, in order to facilitate the implementation convenience of laser induced sintering technology, the regional center position of the target laser sintering area can be designed to overlap with the theoretical center position of the corresponding crystalline silicon solar cell after correction (that is, the default correction reference position of the center part of the crystalline silicon solar cell).

[0079] Step S230, planning a sintering path line in the target laser sintering area according to the battery grid line spacing and the battery grid line length, obtaining a plurality of first sintering path lines and a plurality of second sintering path lines that are parallel to the extension direction of the battery grid line length of the crystalline silicon solar cell and spaced apart from each other, so as to form a laser sintering pattern that matches the crystalline silicon solar cell.

[0080] In this embodiment, a plurality of first sintering path lines (for example, Figure 3 The sintering path lines Aa, Bb, Cc, Dd, Ee, Ff, Gg, Hh and Ii in the target laser sintering area are spaced apart from each other and parallel to the extension direction of the battery grid line length. A plurality of second sintering path lines (for example, Figure 3The sintering path lines Jj, Kk, Ll, Mm, Nn, Oo, Pp, Qq and Rr) are spaced apart from each other and parallel to the length extension direction of the battery grid line, wherein each first sintering path line corresponds to a second sintering path line individually (for example, the sintering path line Aa and the sintering path line Jj correspond to each other, the sintering path line Bb and the sintering path line Kk correspond to each other, the sintering path line Cc and the sintering path line Ll correspond to each other, the sintering path line Dd and the sintering path line Mm correspond to each other, the sintering path line Ee and the sintering path line Nn correspond to each other, the sintering path line Ff and the sintering path line Oo correspond to each other, the sintering path line Gg and the sintering path line Pp correspond to each other, the sintering path line Hh and the sintering path line Qq correspond to each other, and the sintering path line Ii and the sintering path line Rr correspond to each other). Among them, the mutually corresponding first sintering path lines and the second sintering path lines cooperate to realize the laser scanning sintering operation of the same cell grid line; the total number of path lines of the first sintering path lines planned in the target laser sintering area is greater than the total number of cell grid lines of the corresponding crystalline silicon solar cell, so as to ensure that the corresponding planned laser sintering pattern can make the crystalline silicon solar cell be sintered to the maximum extent after actual correction, reduce the influence of factors such as cell correction offset and silicon chip size exceeding the preset size on the sintering result of the solar cell, thereby effectively improving the edge blackening problem of the corresponding EL test image.

[0081] In this process, the theoretical distribution position of each battery grid line that needs to be sintered in the corresponding crystalline silicon solar cell in the straightened state of the battery cell corresponds to a first sintering path line and a second sintering path line separately; the first sintering path line and the second sintering path line corresponding to each other in the target laser sintering area have their own path line endpoints located on opposite sides of the target laser sintering area (for example, a path line endpoint A of the sintering path line Aa is located on the first side of the target laser sintering area that is perpendicular to the extension direction of the battery grid line length, and a path line endpoint J of the sintering path line Jj is located on the second side of the target laser sintering area that is opposite to the first side), and at the same time, the projection line segments of the first sintering path line and the second sintering path line corresponding to each other on any battery grid line partially overlap (that is, the projections of the first sintering path line and the second sintering path line corresponding to each other partially overlap in the extension direction of the battery grid line length), at this time, there will be a partial area overlap between the first sintering area and the second sintering area in the target laser sintering area, and the overlapping sintering area between the first sintering area and the second sintering area can cover the middle area of ​​the corresponding crystalline silicon solar cell (see Figure 3The smaller rectangular dotted line frame area in the target laser induced sintering process) is used to ensure that the middle area of ​​the crystalline silicon solar cell can be laser scanned and sintered twice during the laser induced sintering process, so that the carriers at the corresponding middle area are fully excited to form a sufficient number of metal silicon contact points, so as to effectively improve the pitting or blackening problem in the middle of the image of the corresponding EL test image, and improve the photoelectric conversion efficiency of the corresponding solar cell and the battery production yield, wherein the first sintering area is obtained by determining all the first sintering path coils in the target laser sintering area, and the second sintering area is obtained by determining all the second sintering path coils in the target laser sintering area.

[0082] In this embodiment, the first sintering path line and the second sintering path line corresponding to each other in the target laser sintering area may be on the same straight line or may be staggered. In one implementation of this embodiment, in order to avoid the silicon-based damage phenomenon caused by the excessive total energy of the secondary laser scanning sintering in the overlapping sintering area of ​​the first sintering path line and the second sintering path line corresponding to each other, and effectively suppress the pitting or blackening problem in the middle of the EL test image caused by the silicon-based damage phenomenon, the first sintering path line and the second sintering path line corresponding to each other in the target laser sintering area need to be designed to be staggered, so that the first sintering path line and the second sintering path line corresponding to each other are respectively located on both sides of the corresponding cell grid line responsible for sintering.

[0083] Therefore, the present application can plan an appropriate laser sintering pattern for the crystalline silicon solar cell that needs to be sintered by executing the above-mentioned steps S210 to S230, and effectively improve the blackening problem at the edges of the EL test image and the pitting or blackening problem in the middle of the image through the planned laser sintering pattern, thereby improving the photoelectric conversion efficiency of the solar cell and the battery production yield.

[0084] Optionally, see Figure 4 , Figure 4 yes Figure 2 In the embodiment of the present application, the step S230 may include sub-steps S231 to S233 to ensure that the laser sintering pattern planned for the crystalline silicon solar cell can effectively improve the edge blackening problem of the EL test image and the pitting or blackening problem in the middle of the image.

[0085] Sub-step S231, on the first side of the target laser sintering area perpendicular to the extension direction of the battery grid line length, determine multiple first path line endpoints according to the battery grid line spacing, and on the second side of the target laser sintering area opposite to the first side, determine multiple second path line endpoints according to the battery grid line spacing.

[0086] In this embodiment, the first path line endpoint is used to construct the first sintering path line, and the second path line endpoint is used to construct the second sintering path line. The number of the first path line endpoints is consistent with the number of the second path line endpoints, and each first path line endpoint corresponds to a second path line endpoint. If the first sintering path line and the second sintering path line that need to correspond to each other are located on both sides of the corresponding cell grid line responsible for sintering, the projection position spacing of the first path line endpoint and the second path line endpoint that correspond to each other on any straight line perpendicular to the extension direction of the cell grid line length must be greater than the cell grid line width.

[0087] In one implementation of the present embodiment, in order to effectively simplify the planning process of the laser sintering pattern, the actual spacing between two adjacent first path line endpoints among multiple first path line endpoints can be directly set to the battery grid line spacing, and the actual spacing between two adjacent second path line endpoints among multiple second path line endpoints can be directly set to the battery grid line spacing.

[0088] In another implementation of this embodiment, in order to effectively improve the laser sintering accuracy of the crystalline silicon solar cell and reduce the interference of factors such as cell alignment offset and silicon cell size exceeding the preset size on the sintering result of the solar cell, the first path line endpoint spacing (i.e., the actual spacing between two adjacent first path line endpoints) on the first side within the theoretical normalized projection range of the crystalline silicon solar cell can be directly set as the cell grid line spacing (see Figure 5 The first path line endpoint spacing of the first path line endpoints C, D, E, F and G in the first side is the battery grid line spacing), and the endpoint density of the first path line endpoints within the non-theoretical normalized projection range on the first side is increased (see Figure 5 The endpoint spacing between the first path line endpoints A and B in the embodiment is significantly smaller than the battery grid line spacing, and the endpoint spacing between the first path line endpoints H and I is significantly smaller than the battery grid line spacing), and at the same time, the endpoint spacing of the second path line on the second side within the theoretical normalized projection range (i.e., the actual spacing between two adjacent second path line endpoints) is directly set to the battery grid line spacing (see Figure 5 The first path line endpoint spacing of the second path line endpoints L, M, N, O and P in the battery grid line spacing is the battery grid line spacing), and the endpoint density of the second path line endpoints within the non-theoretical normalized projection range on the second side is increased (see Figure 5 The endpoint spacing between the second path line endpoints J and K is significantly smaller than the battery grid line spacing, and the endpoint spacing between the second path line endpoints Q and R is significantly smaller than the battery grid line spacing), wherein the theoretical normalized projection range is used to characterize the projection line segment range of the theoretical distribution position of the crystalline silicon solar cell after normalization on the first side or the second side.

[0089] At this time, for the target edge of the target laser sintering area, the step of determining a plurality of first path line endpoints or second path line endpoints according to the battery grid line spacing may include:

[0090] Determine a normalized projection line segment of the crystalline silicon solar cell on the target edge along the extension direction of the battery grid line, wherein the target edge is a first edge that matches the endpoint of the first path line, or the target edge is a second edge that matches the endpoint of the second path line, and the normalized projection line segment is used to characterize the theoretical normalized projection range;

[0091] Selecting a plurality of first discrete points in the normalized projection line segment according to the battery grid line spacing, and using each selected first discrete point as a first path line endpoint or a second path line endpoint, wherein the distance between two adjacent first discrete points is consistent with the battery grid line spacing;

[0092] A plurality of second discrete points are selected according to the target spacing in the remaining line segments of the target edge except the normalized projection line segment, and each selected second discrete point is used as a first path line endpoint or a second path line endpoint, wherein the distance between two adjacent second discrete points is consistent with the target spacing, and the target spacing is obtained by multiplying the battery grid line spacing by a preset spacing coefficient, and the preset spacing coefficient is a positive number less than 1.

[0093] Sub-step S232, for each target path line endpoint among the plurality of first path line endpoints and the plurality of second path line endpoints, determining a desired path line endpoint corresponding to the target path line endpoint according to the battery gate line length along the extending direction of the battery gate line length.

[0094] In this embodiment, for a single target path line endpoint, the desired path line endpoint corresponding to the target path line endpoint is located on a straight line along the edge of the middle region of the crystalline silicon solar cell away from the target path line endpoint when the cell is in the corrected state, and the extension direction of the straight line where the target path line endpoint and the corresponding desired path line endpoint are located is parallel to the extension direction of the battery grid line length; the middle region of the crystalline silicon solar cell may include a first middle region edge and a second middle region edge, wherein the first middle region edge and the second middle region edge are parallel to each other and are both perpendicular to the extension direction of the battery grid line length; when When the crystalline silicon solar cell is in the cell correction state, the edge of the first middle region is distributed close to the second edge in the laser sintering plane, and the edge of the second middle region is distributed close to the first edge in the laser sintering plane. At this time, the middle region edge straight line corresponding to the edge of the first middle region in the laser sintering plane (i.e., the straight line corresponding to the edge of the middle region) is the theoretical correction mapping straight line of the edge of the first middle region in the laser sintering pattern, and the middle region edge straight line corresponding to the edge of the second middle region in the laser sintering plane is the theoretical correction mapping straight line of the edge of the second middle region in the laser sintering pattern. For example, Figure 6 Taking the first path line endpoint A and the second path line endpoint N shown as examples, when the first path line endpoint A is used as the target path line endpoint, the expected path line endpoint corresponding to the first path line endpoint A is the path line endpoint a on the middle area edge straight line where the first middle area edge is located, and the middle area edge straight line where the first middle area edge is located is far away from the first path line endpoint A; when the second path line endpoint N is used as the target path line endpoint, the expected path line endpoint corresponding to the second path line endpoint N is the path line endpoint n on the middle area edge straight line where the second middle area edge is located, and the middle area edge straight line where the second middle area edge is located is far away from the second path line endpoint N.

[0095] In this embodiment, the specific size of the middle area of ​​any crystalline silicon solar cell can be estimated by the laser induced sintering device 10 according to the layout size, or can be accurately calculated by the laser induced sintering device 10 according to a preset area ratio.

[0096] Optionally, in an implementation of this embodiment, for each target path line endpoint in the plurality of first path line endpoints and the plurality of second path line endpoints, the sub-step S232 may include:

[0097] Calculating a first distance between an edge of a target middle region corresponding to an endpoint of the target path line and an edge of a target cell in the crystalline silicon solar cell according to an area ratio of the middle region of the crystalline silicon solar cell and a length of the cell grid line, wherein the edge of the target middle region is distributed away from the endpoint of the target path line, and the edge of the target cell is distributed close to the endpoint of the target path line;

[0098] Calculating a second distance from an endpoint of the target path line to an edge of the target cell according to a relative normalized position relationship between the crystalline silicon solar cell and the target laser sintering area;

[0099] A desired path line endpoint matching the target path line endpoint is determined in the target laser sintering area along the battery grid line length extension direction, wherein the distance between the desired path line endpoint and the target path line endpoint is obtained by adding the first distance and the second distance.

[0100] The relative normalized position relationship is used to describe the relative position relationship between the area demarcated position of the target laser sintering area in the laser sintering plane and the theoretical distribution position of the corresponding crystalline silicon solar cell after normalization. For a single target path line endpoint, the first distance between the edge of the target middle area and the edge of the target cell corresponding to the target path line endpoint is calculated using the following formula:

[0101]

[0102] Wherein, d1 is used to represent the first distance, p is used to represent the area ratio of the middle region, and l is used to represent the length of the battery grid line.

[0103] Therefore, the present application can ensure that the first sintering path line and the second sintering path line corresponding to each other can collaboratively achieve the secondary laser scanning sintering effect of the corresponding battery cell grid line in the middle area by executing the specific step process of the above sub-step S232.

[0104] Sub-step S233, performing sintering path line planning between the target path line endpoint and the desired path line endpoint corresponding to the target path line endpoint to obtain a first sintering path or a second sintering path.

[0105] Among them, if the target path line endpoint is a first path line endpoint, then the sintering path line planned based on the target path line endpoint and the corresponding expected path line endpoint is a first sintering path line; if the target path line endpoint is a second path line endpoint, then the sintering path line planned based on the target path line endpoint and the corresponding expected path line endpoint is a second sintering path line.

[0106] Therefore, the present application can ensure that the laser sintering pattern planned for the crystalline silicon solar cell can effectively improve the edge blackening problem of the EL test image and the pitting or blackening problem in the middle of the image by executing the above sub-steps S231 to S233.

[0107] In this case, the laser sintering pattern provided by the present application for any crystalline silicon solar cell can be as follows: Figure 7 As shown. In the embodiment of the present application, the graphic size of the laser sintering pattern provided in the embodiment of the present application will be larger than the layout size of the crystalline silicon solar cell, so that the complete laser sintering area (i.e., the target laser sintering area) corresponding to the laser induced sintering device 10 can fully cover the corrected crystalline silicon solar cell, so as to provide the crystalline silicon solar cell with redundant laser sintering coverage space, ensure that the crystalline silicon solar cell can be sintered to the maximum extent, and improve the edge blackening problem of the corresponding EL test image. Among them, the graphic size of the laser sintering pattern can be expressed by the area size of the above-mentioned target laser sintering area.

[0108] Meanwhile, in the embodiment of the present application, the laser sintering pattern includes a plurality of first sintering path lines (for example, Figure 7 A first sintering path line Aa, Bb, Cc, Dd, Ee, Ff, Gg, Hh and Ii) and a plurality of second sintering path lines (e.g., Figure 7 The laser sintering pattern is a laser sintering pattern having a plurality of first sintering path lines Jj, Kk, Ll, Mm, Nn, Oo, Pp, Qq and Rr, wherein one line end point (i.e., path line end point) of each of the plurality of first sintering path lines is located on the first graphic boundary of the laser sintering pattern, and one line end point (i.e., path line end point) of each of the plurality of second sintering path lines is located on the second graphic boundary of the laser sintering pattern, and the first graphic boundary and the second graphic boundary are arranged opposite to each other. The first graphic boundary of the laser sintering pattern can be represented by the first side of the target laser sintering area, and the second graphic boundary of the laser sintering pattern can be represented by the second side of the target laser sintering area.

[0109] In the laser sintering pattern provided in the present application, each first sintering path line corresponds to a second sintering path line individually (for example, the sintering path line Aa and the sintering path line Jj correspond to each other, the sintering path line Bb and the sintering path line Kk correspond to each other, the sintering path line Cc and the sintering path line Ll correspond to each other, the sintering path line Dd and the sintering path line Mm correspond to each other, the sintering path line Ee and the sintering path line Nn correspond to each other, the sintering path line Ff and the sintering path line Oo correspond to each other, the sintering path line Gg and the sintering path line Pp correspond to each other, the sintering path line Hh and the sintering path line Qq correspond to each other, and the sintering path line Ii and the sintering path line Rr correspond to each other). Among them, the first sintering path line and the second sintering path line corresponding to each other cooperate to realize the laser scanning sintering operation of the same cell grid line; the total number of path lines of the first sintering path line in the laser sintering pattern is greater than the total number of cell grid lines of the corresponding crystalline silicon solar cell, so as to ensure that the laser sintering pattern can make the crystalline silicon solar cell be sintered to the maximum extent after actual correction, reduce the influence of factors such as cell correction offset and silicon chip size exceeding the preset size on the sintering result of the solar cell, thereby effectively improving the edge blackening problem of the corresponding EL test image.

[0110] In addition, in the laser sintering pattern provided in the present application, the first sintering path line and the second sintering path line corresponding to each other are partially projected and overlapped in the extension direction of the battery grid line length, so as to ensure that the middle area of ​​the corresponding crystalline silicon solar cell can be laser scanned and sintered twice during the laser induced sintering process, so that the carriers in the corresponding middle area can be fully excited to form a sufficient number of metal silicon contact points, so as to effectively improve the problem of pitting or blackening in the middle of the image of the corresponding EL test image, and improve the photoelectric conversion efficiency of the corresponding solar cell and the battery production yield.

[0111] In this embodiment, the first sintering path line and the second sintering path line corresponding to each other in the laser sintering pattern may be on the same straight line, or may be staggered. In one implementation of this embodiment, in order to avoid the silicon-based damage phenomenon caused by the excessive total energy of the secondary laser scanning sintering in the overlapping sintering area of ​​the first sintering path line and the second sintering path line corresponding to each other, and to effectively suppress the pitting or blackening problem in the middle of the EL test image caused by the silicon-based damage phenomenon, the first sintering path line and the second sintering path line corresponding to each other in the laser sintering pattern need to be designed to be staggered, so that the first sintering path line and the second sintering path line corresponding to each other are respectively located on both sides of the corresponding battery cell grid line responsible for sintering.

[0112] In this embodiment, the area within the laser sintering pattern that is consistent with the theoretical normalized distribution area (see Figure 7Among the multiple first sintering path lines intersecting with the area encircled by two cut-corner rectangular dotted frames in the laser sintering pattern, the actual spacing between two adjacent first sintering path lines is consistent with the battery grid line spacing of the crystalline silicon solar cell. At the same time, among the multiple second sintering path lines intersecting with the theoretical normalized distribution area in the laser sintering pattern, the actual spacing between two adjacent second sintering path lines is consistent with the battery grid line spacing.

[0113] In this embodiment, the first sintering path line density of the laser sintering pattern in the graphic area other than the theoretical normalized distribution area is greater than or equal to the first sintering path line density in the theoretical normalized distribution area, and the second sintering path line density of the laser sintering pattern in the graphic area other than the theoretical normalized distribution area is greater than or equal to the second sintering path line density in the theoretical normalized distribution area. Specifically, among the multiple first sintering path lines in the laser sintering pattern that do not intersect with the theoretical normalized distribution area, the actual spacing between two adjacent first sintering path lines is less than or equal to the battery grid line spacing, and at the same time, among the multiple second sintering path lines in the laser sintering pattern that do not intersect with the theoretical normalized distribution area, the actual spacing between two adjacent second sintering path lines is less than or equal to the battery grid line spacing; wherein, the smaller the actual spacing between two adjacent first sintering path lines or second sintering path lines, the greater the density of the first sintering path lines or the second sintering path lines in the corresponding graphic area, the more the laser sintering accuracy of the crystalline silicon solar cell can be improved, and the interference of factors such as cell normalization offset and silicon wafer size exceeding the preset size on the sintering result of the solar cell can be further reduced.

[0114] In this embodiment, the other line endpoint (i.e., the path line endpoint) of each first sintering path line in the laser sintering pattern is located at the edge of the first middle area of ​​the crystalline silicon solar cell on the theoretical corrected mapping straight line within the laser sintering pattern, and the other line endpoint (i.e., the path line endpoint) of each second sintering path line is located at the edge of the second middle area of ​​the crystalline silicon solar cell on the theoretical corrected mapping straight line within the laser sintering pattern, wherein the edge of the first middle area and the edge of the second middle area are parallel to each other and perpendicular to the extension direction of the length of the battery grid line, the theoretical corrected mapping straight line of the edge of the first middle area is close to the boundary of the second figure, and the theoretical corrected mapping straight line of the edge of the second middle area is close to the boundary of the first figure, so as to ensure that the corresponding first sintering path line and the second sintering path line can cooperate to achieve the secondary laser scanning sintering effect of the corresponding battery grid line in the middle area.

[0115] In the present application, in order to ensure that the above-mentioned laser induced sintering equipment 10 can perform laser scanning sintering according to the laser sintering pattern adapted to the crystalline silicon solar cell to be sintered, so as to improve the edge blackening problem and the pitting or blackening problem in the middle of the image in the EL test image of the corresponding crystalline silicon solar cell, so as to improve the photoelectric conversion efficiency and battery production yield of the corresponding solar cell, the embodiment of the present application provides a laser sintering control method applied to the above-mentioned laser induced sintering equipment 10 to achieve the above-mentioned purpose. The laser sintering control method provided by the present application is described in detail below.

[0116] Please refer to Figure 8 , Figure 8 is a schematic flow chart of the laser sintering control method provided in the embodiment of the present application. In the embodiment of the present application, Figure 8 The laser sintering control method shown may include step S310 and step S320.

[0117] Step S310, obtaining a laser sintering pattern that matches the crystalline silicon solar cell wafer rectified in the laser sintering plane.

[0118] In this embodiment, after the crystalline silicon solar cell to be sintered completes the correction operation in the laser sintering plane of the laser induced sintering device 10, the laser induced sintering device 10 can obtain the relevant parameter data of the crystalline silicon solar cell (including the layout size, the cell grid line length and the cell grid line spacing), and perform a graphic search in the laser sintering graphic database according to the obtained relevant parameter data, so as to obtain the laser sintering graphic matching the crystalline silicon solar cell. Among them, the laser sintering graphic database records the laser sintering graphics of the crystalline silicon solar cells of different cell designs and / or cell specifications, and the light sintering graphics of each crystalline silicon solar cell are planned by any one of the laser sintering graphic planning methods provided above; the laser sintering graphic database can be deployed at the main control unit 11 included in the laser induced sintering device 10, and the laser sintering graphic database can also be deployed on a data server that is connected to the main control unit 11 in communication.

[0119] Step S320, applying a reverse bias voltage to the crystalline silicon solar cell, and driving the laser assembly to perform laser scanning according to a plurality of first sintering path lines in the laser sintering pattern, and then driving the laser assembly to perform laser scanning and irradiation according to a plurality of second sintering path lines in the laser sintering pattern, so as to sinter all the cell grid lines that need to be sintered in the crystalline silicon solar cell.

[0120] Among them, the laser induced sintering equipment 10 can drive the reverse voltage applying unit 13 through the main control unit 11 to apply a reverse bias voltage on the crystalline silicon solar cell after the correction operation is completed, and at the same time drive the laser component 12 to perform laser scanning according to multiple first sintering path lines in the found laser sintering pattern, and then perform laser scanning and irradiation according to multiple second sintering path lines in the found laser sintering pattern, so as to perform laser scanning and sintering on all battery grid lines in the crystalline silicon solar cell, ensuring that the actual sintering result of the crystalline silicon solar cell can effectively improve the blackening problem of the edges of the corresponding EL test image and the pitting or blackening problem in the middle of the image, thereby effectively improving the photoelectric conversion efficiency and battery production yield of the corresponding solar cell on the basis of effectively reducing the metal contact resistance of the corresponding solar cell by using laser induced sintering technology.

[0121] In one implementation of this embodiment, the diameter range of the circular laser spot or the side length range of the square laser spot of the laser component 12 on the crystalline silicon solar cell is 90-120 μm, and the laser scanning rate of the laser component 12 is greater than 50 m / s.

[0122] It is understandable that because the laser sintering control method provided in the present application will cause the middle area of ​​the crystalline silicon solar cell to undergo two laser scanning sinterings, in order to avoid the silicon-based damage phenomenon and the pitting or blackening problem in the middle of the EL test image due to the excessive total energy of the two laser scanning sinterings in the middle area, the laser induced sintering equipment 10 needs to lower the laser emission power of the laser component 12 and the reverse bias voltage applied by the reverse voltage application unit 13, so that the carrier excitation energy borne by the crystalline silicon solar cell during a single laser scanning sintering process is lower than the carrier excitation energy when the conventional laser induced sintering technology is applied.

[0123] Therefore, the present application can perform laser scanning sintering according to the laser sintering pattern adapted to the crystalline silicon solar cell by executing the above-mentioned steps S310 and S320, so as to improve the edge blackening problem and the pitting or blackening problem in the middle of the image in the EL test image of the corresponding crystalline silicon solar cell, thereby improving the photoelectric conversion efficiency and battery production yield of the corresponding solar cell.

[0124] On this basis, an embodiment of the present application can provide a crystalline silicon solar cell, which can include a cell substrate and a plurality of cell grid lines screen-printed on the cell substrate; wherein each cell grid line is laser scanned and sintered based on a laser sintering pattern adapted to the crystalline silicon solar cell; the laser sintering pattern adapted to the crystalline silicon solar cell can be planned using any one of the laser sintering pattern planning methods described above, and the crystalline silicon solar cell can be laser scanned and sintered using the laser sintering control method described above to ensure that the crystalline silicon solar cell provided by the present application has minimal edge blackening problems and pitting or blackening problems in the middle of the image in the corresponding EL test image, thereby effectively improving the photoelectric conversion efficiency of the corresponding solar cell and the battery production yield.

[0125] In addition, the embodiment of the present application can also provide a photovoltaic module, which can include a plurality of crystalline silicon solar cells, and the plurality of crystalline silicon solar cells are arranged in an array. Each crystalline silicon solar cell in the photovoltaic module is obtained by laser scanning and sintering using an adapted laser sintering pattern to ensure that the photovoltaic module has good photoelectric conversion efficiency and device reliability.

[0126] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic, for example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to the embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and a module, a program segment or a part of a code contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or the flowchart, and the combination of boxes in the block diagram and / or the flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0127] In addition, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist separately, or two or more modules can be integrated to form an independent part. If the various functions provided by the present application are implemented in the form of software functional modules and sold or used as independent products, they can be stored in a storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a readable storage medium, including a number of instructions for a laser induced sintering device to perform all or part of the steps of the method recorded in each embodiment of the present application. The aforementioned readable storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or CD-ROM and other media that can store program codes.

[0128] The above are only various implementations of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A laser sintering pattern of a crystalline silicon solar cell, characterized in that: The pattern size of the laser sintering pattern is larger than the layout size of the crystalline silicon solar cell. The laser sintering pattern includes a plurality of first sintering path lines and a plurality of second sintering path lines which are parallel to the extension direction of the cell grid line of the crystalline silicon solar cell and are spaced apart from each other, wherein one line end point of each of the plurality of first sintering path lines is located on the first pattern boundary of the laser sintering pattern, one line end point of each of the plurality of second sintering path lines is located on the second pattern boundary of the laser sintering pattern, and the first pattern boundary is arranged opposite to the second pattern boundary; Each first sintering path line corresponds to a second sintering path line individually, and the corresponding first sintering path lines and second sintering path lines partially overlap in the extension direction of the battery grid line length, wherein the corresponding first sintering path lines and second sintering path lines are used to realize laser scanning sintering of the same battery cell grid line.

2. The laser sintering pattern according to claim 1, characterized in that: Among the plurality of first sintering path lines intersecting with the theoretically normalized distribution area, the actual spacing between two adjacent first sintering path lines is consistent with the spacing between the cell grid lines of the crystalline silicon solar cell, wherein the theoretically normalized distribution area is used to represent the actual mapping area of ​​the theoretical distribution position of the crystalline silicon solar cell after normalization within the laser sintering pattern; Among the plurality of second sintering path lines intersecting the theoretical normalized distribution area, the actual spacing between two adjacent second sintering path lines is consistent with the battery grid line spacing.

3. The laser sintering pattern according to claim 2, characterized in that: Among the plurality of first sintering path lines that do not intersect the theoretical normalized distribution area, the actual spacing between two adjacent first sintering path lines is smaller than the battery grid line spacing; Among the plurality of second sintering path lines that do not intersect the theoretical normalized distribution area, the actual spacing between two adjacent second sintering path lines is smaller than the battery grid line spacing.

4. The laser sintering pattern according to claim 1, characterized in that: The other line endpoint of each first sintering path line is located on the theoretically corrected mapping straight line of the first middle area edge of the crystalline silicon solar cell within the laser sintering pattern, and the other line endpoint of each second sintering path line is located on the theoretically corrected mapping straight line of the second middle area edge of the crystalline silicon solar cell within the laser sintering pattern, wherein the first middle area edge and the second middle area edge are parallel to each other and perpendicular to the extension direction of the battery grid line length, the theoretically corrected mapping straight line of the first middle area edge is close to the second figure boundary, and the theoretically corrected mapping straight line of the second middle area edge is close to the first figure boundary.

5. The laser sintering pattern according to any one of claims 1 to 4, characterized in that: The first sintering path lines and the second sintering path lines corresponding to each other are staggeredly distributed in the laser sintering pattern.

6. A laser sintering pattern planning method, characterized in that: The method comprises: Obtaining the layout size, cell grid line length and cell grid line spacing of the crystalline silicon solar cell to be sintered; In a laser sintering plane of a laser induced sintering device, a target laser sintering area that can cover the normalized crystalline silicon solar cell is determined according to the layout size, wherein the area size of the target laser sintering area is larger than the layout size; According to the battery grid line spacing and the battery grid line length, sintering path line planning is performed in the target laser sintering area to obtain a plurality of first sintering path lines and a plurality of second sintering path lines that are parallel to the battery grid line length extension direction of the crystalline silicon solar cell and spaced from each other, so as to form a laser sintering pattern matching the crystalline silicon solar cell, wherein each first sintering path line corresponds to a second sintering path line individually, and each of the corresponding first sintering path line and the corresponding second sintering path line has a path line endpoint located on the opposite side of the target laser sintering area, and the corresponding first sintering path line and the second sintering path line partially overlap in projection in the battery grid line length extension direction, wherein the corresponding first sintering path line and the second sintering path line cooperate to realize laser scanning sintering of the same battery cell grid line.

7. The method according to claim 6, characterized in that The step of planning a sintering path line in the target laser sintering area according to the cell grid line spacing and the cell grid line length to obtain a plurality of first sintering path lines and a plurality of second sintering path lines that are parallel to the extension direction of the cell grid line length of the crystalline silicon solar cell and spaced from each other comprises: On a first side of the target laser sintering area perpendicular to the extending direction of the battery grid line length, a plurality of first path line endpoints are determined according to the battery grid line spacing, and on a second side of the target laser sintering area opposite to the first side, a plurality of second path line endpoints are determined according to the battery grid line spacing; For each target path line endpoint among the plurality of first path line endpoints and the plurality of second path line endpoints, determining a desired path line endpoint corresponding to the target path line endpoint according to the battery grid line length along the extending direction of the battery grid line length, wherein the desired path line endpoint is located on a straight line along the edge of a middle area of ​​the crystalline silicon solar cell away from the target path line endpoint; A sintering path line is planned between the target path line endpoint and the desired path line endpoint corresponding to the target path line endpoint to obtain a first sintering path line or a second sintering path line.

8. The method according to claim 7, characterized in that The step of determining a plurality of first path line endpoints or second path line endpoints on a target edge of the target laser sintering area according to the battery grid line spacing comprises: Determine a normalized projection line segment of the crystalline silicon solar cell on the target edge along the extending direction of the battery grid line, wherein the target edge is a first edge matching the endpoint of the first path line, or the target edge is a second edge matching the endpoint of the second path line; Selecting a plurality of first discrete points in the normalized projection line segment according to the battery grid line spacing, and using each selected first discrete point as a first path line endpoint or a second path line endpoint, wherein the distance between two adjacent first discrete points is consistent with the battery grid line spacing; A plurality of second discrete points are selected according to the target spacing in the remaining line segments of the target edge except the normalized projection line segment, and each selected second discrete point is used as a first path line endpoint or a second path line endpoint, wherein the distance between two adjacent second discrete points is consistent with the target spacing, and the target spacing is obtained by multiplying the battery grid line spacing by a preset spacing coefficient, and the preset spacing coefficient is a positive number less than 1.

9. The method according to claim 7, characterized in that: The step of determining the desired path line endpoint corresponding to the target path line endpoint according to the battery grid line length along the extending direction of the battery grid line length comprises: Calculating a first distance between an edge of a target middle region corresponding to an endpoint of the target path line and an edge of a target cell in the crystalline silicon solar cell according to an area ratio of the middle region of the crystalline silicon solar cell and a length of the cell grid line, wherein the edge of the target middle region is distributed away from the endpoint of the target path line, and the edge of the target cell is distributed close to the endpoint of the target path line; Calculating a second distance from an endpoint of the target path line to an edge of the target cell according to a relative normalized position relationship between the crystalline silicon solar cell and the target laser sintering area; A desired path line endpoint matching the target path line endpoint is determined in the target laser sintering area along the battery grid line length extension direction, wherein the distance between the desired path line endpoint and the target path line endpoint is obtained by adding the first distance and the second distance.

10. The method according to claim 9, characterized in that The first distance between the edge of the target middle area corresponding to the endpoint of the target path line and the edge of the target cell is calculated using the following formula: Wherein, d1 is used to represent the first distance, p is used to represent the area ratio of the middle region, and l is used to represent the length of the battery grid line.

11. The method according to any one of claims 6 to 10, characterized in that: The first sintering path lines and the second sintering path lines corresponding to each other are staggeredly distributed in the target laser sintering area.

12. A laser sintering control method, characterized in that: Applied to laser induced sintering equipment, the method comprises: Obtaining a laser sintering pattern according to any one of claims 1 to 5 that matches the crystalline silicon solar cell corrected in the laser sintering plane, wherein the laser sintering pattern is planned using the laser sintering pattern planning method according to any one of claims 6 to 11; A reverse bias voltage is applied to the crystalline silicon solar cell, and the laser component is driven to perform laser scanning according to a plurality of first sintering path lines in the laser sintering pattern, and then the laser component is driven to perform laser scanning and irradiation according to a plurality of second sintering path lines in the laser sintering pattern, so as to sinter all battery grid lines that need to be sintered in the crystalline silicon solar cell.

13. The method according to claim 12, characterized in that The diameter range of the circular laser spot or the side length range of the square laser spot of the laser assembly on the crystalline silicon solar cell is 90-120 μm.

14. A crystalline silicon solar cell, characterized in that: The invention comprises a battery cell substrate and a plurality of battery grid lines screen-printed on the battery cell substrate, wherein each battery grid line is subjected to laser scanning sintering based on the laser sintering pattern according to any one of claims 1 to 5.

15. A photovoltaic module, characterized in that: It comprises a plurality of crystalline silicon solar cells as claimed in claim 14, wherein the plurality of crystalline silicon solar cells are arranged in an array.

16. A laser induced sintering device, characterized in that: The device comprises a cell carrier, a laser assembly, a reverse voltage applying unit and a main control unit, wherein the cell carrier is used to carry a crystalline silicon solar cell, the main control unit is electrically connected to the laser assembly and the reverse voltage applying unit respectively, the laser assembly is used to perform laser scanning and irradiation on the crystalline silicon solar cell carried on the cell carrier, and the reverse voltage applying unit is used to apply a reverse bias voltage to the crystalline silicon solar cell; The main control unit stores a computer program, and by running the computer program, implements the laser sintering pattern planning method described in any one of claims 6-11, or drives the laser component and the reverse voltage application unit to collaboratively implement the laser sintering control method described in any one of claims 12-13.

17. A readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the laser induced sintering equipment, the laser sintering pattern planning method described in any one of claims 6 to 11 or the laser sintering control method described in any one of claims 12 to 13 is implemented.

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