Laser doping pattern and solar cell

Abstract

The invention relates to a laser doping pattern and a solar cell. The embodiment of the invention provides a laser doping pattern. The laser doping pattern comprises two end lines, a plurality of auxiliary grid laser lines and a first set of offset lines. The two end lines are oppositely arranged along a first direction. The multiple auxiliary grid laser lines are arranged in parallel in the second direction and located between the two end lines, the second direction is perpendicular to the first direction, the multiple auxiliary grid laser lines have the middle position, and the multiple auxiliary grid laser lines comprise the inner set of auxiliary grid laser lines located in the middle position and the first set of auxiliary grid laser lines located at the outermost end in the second direction. The first group of offset lines comprises first offset lines in one-to-one correspondence with the auxiliary grid laser lines in the first group of auxiliary grid laser lines, the auxiliary grid laser lines corresponding to the first offset lines deviate outwards, and the first offset lines are overlapped with or attached to the corresponding auxiliary grid laser lines. According to the laser doped pattern, the offset effect is improved, the service life of the screen printing plate is prolonged, and the production cost is reduced.

Description

Technical Field

[0001] The present disclosure relates to the technical field of high-efficiency selective emitter laser doping, and particularly to laser doping patterns and solar cells. Background Art

[0002] In the field of solar single-crystal passivated emitter and rear contact (PERC), it involves high-efficiency selective emitter (SE) laser doping technology. Specifically, a doping pattern is formed on the surface layer of the wafer through the SE laser doping technology, and then a front silver electrode is formed by screen printing, so that the front silver electrode is connected to the doping pattern.

[0003] Since the screen is an essential tool in the printing process, the quality of the screen has a great impact on the electroluminescence (EL) problems and efficiency related to printing. Offset is one of the most common EL problems. During the printing process of the front silver electrode of the solar cell, the screen cloth will deform under the pressure of the squeegee, resulting in the offset of the actual front silver electrode printed on the wafer, which is likely to cause the problem of misalignment between the front silver sub-grid lines and the laser doping area. The common solution is to directly replace the screen, but due to the high price of the screen, if the service life is too short, it will cause a great impact on the manufacturing cost.

[0004] It is very urgent to find a solution to extend the service life of the screen and then improve the offset. However, due to the limitations of the current screen material, improving the screen itself has little effect. Summary of the Invention

[0005] Based on this, it is necessary to provide a laser doping pattern and a solar cell for the problem of EL offset in the screen printing process.

[0006] An embodiment of the present disclosure provides a laser doping pattern, which includes two end lines, a plurality of sub-grid laser lines, and a first group of offset lines. The two end lines are oppositely arranged along a first direction. The plurality of sub-grid laser lines are arranged in parallel along a second direction and are located between the two end lines. The second direction is perpendicular to the first direction. The plurality of sub-grid laser lines have a middle position. The plurality of sub-grid laser lines include an inner group of sub-grid laser lines located at the middle position and a first group of sub-grid laser lines located at the outermost ends along the second direction. The first group of offset lines includes first offset lines corresponding one by one to the sub-grid laser lines in the first group of sub-grid laser lines. The first offset lines are offset outward relative to the corresponding sub-grid laser lines, and the first offset lines overlap or abut against the corresponding sub-grid laser lines.

[0007] The laser doping pattern provided by the embodiments of the present disclosure has the first offset line offset outward relative to the corresponding sub-grid laser line, and the first offset line overlaps or abuts against the corresponding sub-grid laser line, so that the width of the formed laser doping region increases outward and is greater than the original width. In this way, even if the positive silver electrode is offset due to the deformation of the screen mesh during actual printing, the positive silver electrode can still be aligned with the formed laser doping region, increasing the alignment accuracy. The technical solution provided by the embodiments of the present disclosure extends the service life of the screen mesh and reduces the production cost.

[0008] In some embodiments, the multiple sub-grid laser lines further include a second group of sub-grid laser lines located inside the first group of sub-grid laser lines. The laser doping pattern further includes a second group of offset lines. The second group of offset lines includes second offset lines corresponding one by one to the sub-grid laser lines in the second group of sub-grid laser lines. The second offset line is offset outward relative to the corresponding sub-grid laser line, and the second offset line overlaps or abuts against the corresponding sub-grid laser line.

[0009] With such an arrangement, corresponding offset lines are offset outside the multiple groups of sub-grid laser lines, and the multiple groups of sub-grid laser lines overlap or abut against the corresponding offset lines to form multiple laser doping regions with increased widths outward. The alignment accuracy between the multiple laser doping regions with increased widths and the multiple offset positive silver electrodes is improved. The service life of the screen mesh is extended, and the production cost is reduced.

[0010] In some embodiments, the length of the second offset line in the first direction is shorter than the length of the first offset line in the first direction.

[0011] With such an arrangement, since the closer to the outer sub-grid laser line, the greater the deformation of the screen mesh and the greater the offset amount, setting the length of the first offset line in the first direction to be greater than the length of the second offset line in the first direction can reduce the offset error and improve the alignment accuracy.

[0012] In some embodiments, the laser doping pattern has eight regions equally divided along the second direction, namely the left one region, the left two region, the left three region, the left four region, the right four region, the right three region, the right two region and the right one region. The inner group of sub-grid laser lines is located in the left four region and the right four region, the first group of offset lines is located in the left one region and the right one region, and the second group of offset lines is located in the left two region and the right two region. The multiple sub-grid laser lines further include a third group of sub-grid laser lines located in the left three region and the right three region. The laser doping pattern further includes a third group of offset lines. The third group of offset lines includes third offset lines corresponding one by one to the sub-grid laser lines in the third group of sub-grid laser lines. The third offset line is offset outward relative to the corresponding sub-grid laser line, and the third offset line overlaps or abuts against the corresponding sub-grid laser line.

[0013] With such an arrangement, the setting of the three groups of opposite offset lines can better improve the offset effect, reduce the offset error and improve the alignment accuracy.

[0014] In some embodiments, the ratio of the length of the offset line in the first group of offset lines to the length of the corresponding laser line is from 1 / 2 to 1. The ratio of the length of the offset line in the second group of offset lines to the length of the corresponding laser line is from 1 / 4 to 1 / 2. The ratio of the length of the offset line in the third group of offset lines to the length of the corresponding laser line is from 1 / 8 to 1 / 4.

[0015] With such a setting, since the degree of deformation of the stencil gradually decreases from the laser line corresponding to the first group of offset lines to the laser line corresponding to the third group of offset lines, the area of the laser doping region formed by the overlap or abutment of the sub-grid laser line and the corresponding offset line also gradually decreases. Therefore, the length of the first group of offset lines to the length of the third group of offset lines gradually decreases. While improving the offset effect, the influence on the electrical performance of the battery is reduced.

[0016] In some embodiments, it further includes a marking point and a chamfering line. The marking point is located between two end lines, and the marking point is spaced apart from the sub-grid laser line. The chamfering line is connected to the corresponding end line and the outermost sub-grid laser line among the multiple sub-grid laser lines.

[0017] With such a setting, the connection of the chamfering line, the end line, and the outermost sub-grid laser line defines the shape of the outermost end of the laser doping pattern. The marking point defines the distance from the edge for positioning, increasing the alignment accuracy.

[0018] In some embodiments, it further includes two end offset lines. The end offset lines are offset inward relative to the corresponding end lines and overlap or abut against the corresponding end lines.

[0019] Due to the inward offset of the stencil relative to the end line, the laser doping region formed by the end offset lines offsetting inward relative to the corresponding end lines and overlapping or abutting against the corresponding end lines increases the alignment rate and improves the offset effect.

[0020] In some embodiments, it further includes a first group of additional offset lines and a second group of additional offset lines.

[0021] The first group of additional offset lines includes first additional offset lines corresponding one-to-one to the first offset lines in the first group of offset lines. The first additional offset lines are offset outward relative to the corresponding first offset lines, and the first additional offset lines overlap or abut against the corresponding first offset lines.

[0022] The first additional offset line has the same length as the corresponding first offset line.

[0023] The second group of additional offset lines includes second additional offset lines corresponding one-to-one to the two end offset lines. The second additional offset lines are offset inward relative to the corresponding end offset lines, and the second additional offset lines overlap or abut against the corresponding end offset lines.

[0024] The ratio of the length of the end offset line to the span of the multiple sub-grid laser lines in the second direction is from 1 / 2 to 1.

[0025] With such a setting, the area formed by the additional offset line and the offset line further improves the alignment accuracy between the laser doping area and the front silver electrode, further extends the service life of the stencil, and reduces the production cost.

[0026] An embodiment of the present disclosure also provides a laser doping pattern. The laser doping pattern includes multiple laser lines, and the multiple laser lines include two end lines, multiple sub-grid laser lines, and two end offset lines. The two end lines are arranged opposite to each other in the first direction. The multiple sub-grid laser lines are arranged side by side in the second direction and are located between the two end lines. The second direction is perpendicular to the first direction, and the multiple sub-grid laser lines have a middle position. The end offset line is offset inward relative to the corresponding end line and overlaps or abuts against the corresponding end line.

[0027] In the laser doping pattern provided by the embodiment of the present disclosure, the end offset line is offset inward relative to the corresponding end line and overlaps or abuts against the corresponding end line, and the formed laser doping area improves the alignment accuracy with the front silver electrode that generates the offset. The service life of the stencil is extended, and the production cost is reduced.

[0028] An embodiment of the present disclosure also provides a solar cell. The solar cell includes a substrate, the above-mentioned laser doping pattern, and electrode lines. The laser doping pattern extends into the substrate. The electrode lines are stacked on the laser doping pattern.

[0029] In the solar cell provided by the embodiment of the present disclosure, the alignment accuracy of the laser doping pattern is improved, the EL problem caused by printing offset is reduced, the printing cost is reduced, and the printing efficiency is improved. At the same time, the quality of the solar cell is improved. Description of the Drawings

[0030] Figure 1 Schematic diagram of the detection effect of the solar cell produced after the stencil is deformed in the comparative example;

[0031] Figure 2 Schematic diagram of the detection effect of another solar cell produced after the stencil is deformed in the comparative example;

[0032] Figure 3 Simplified schematic diagram of the solar cell in the comparative example;

[0033] Figure 4 Simplified schematic diagram of the laser doping pattern in the comparative example;

[0034] Figure 5 Structural schematic diagram of the laser doping pattern of the embodiment of the present disclosure;

[0035] Figure 6 ForFigure 5 Schematic enlarged structure diagram at position A;

[0036] Figure 7 Schematic structure diagram of the solar cell provided by the embodiment of the present disclosure;

[0037] Figure 8 is Figure 7 Cross-sectional view in the B-B direction;

[0038] Figure 9 Simplified schematic diagram of the laser doping pattern of the embodiment of the present disclosure;

[0039] Figure 10 Simplified schematic diagram of the laser doping pattern of the embodiment of the present disclosure;

[0040] Figure 11 Simplified schematic diagram of the laser doping pattern of the embodiment of the present disclosure.

[0041] Explanation of reference numerals: 1, substrate; 2, laser doping pattern; 201, end line; 202, chamfer line; 203, marking point; 204, sub-grid laser line; 20, inner group of sub-grid laser lines; 21, first group of sub-grid laser lines; 22, second group of sub-grid laser lines; 23, third group of sub-grid laser lines; 310, first group of offset lines; 311, first offset line; 320, second group of offset lines; 321, second offset line; 330, third group of offset lines; 331, third offset line; 340, end offset line; 40, laser spot; 401, first laser spot; 402, second laser spot; 510, first group of additional offset lines; 511, first additional offset line; 520, second group of additional offset lines; 521, second additional offset line; 6, electrode line; 1000, solar cell. Detailed implementation manners

[0042] To make the above-mentioned objects, features and advantages of the embodiments of the present disclosure more obvious and understandable, the following will describe in detail the specific implementation manners of the embodiments of the present disclosure with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the embodiments of the present disclosure. However, the embodiments of the present disclosure can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the embodiments of the present disclosure. Therefore, the embodiments of the present disclosure are not limited by the specific examples disclosed below.

[0043] In the description of the embodiments of the present disclosure, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "perpendicular", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the embodiments of the present disclosure.

[0044] In the embodiments of the present disclosure, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0045] In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. Exemplarily, the first laser spot may also be referred to as the second laser spot, and the second laser spot may also be referred to as the first laser spot. In the description of the embodiments of the present disclosure, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0046] In the embodiments of the present disclosure, unless otherwise clearly specified and limited, the terms "connected" and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a flexible connection or a rigid connection along at least one direction; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, or there may be an intermediate medium while being directly connected, and it may also be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. The terms "installed", "set", "fixed", etc. can be understood in a broad sense as connection. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0047] As used herein, the terms "layer" and "region" refer to a portion of a material that includes an area with a certain thickness. A layer can extend horizontally, vertically and / or along a tapered surface. A layer can be an area of ​​a uniform or non-uniform continuous structure, and its thickness perpendicular to the extension direction may not be greater than the thickness of the continuous structure. A layer can include multiple layers, which can be stacked layers or multiple layers extending discretely. The shapes of various regions and layers in the drawings and their relative sizes and positional relationships are only exemplary, and may actually deviate due to manufacturing tolerances or technical limitations, and the design can be adjusted according to actual needs.

[0048] refer to Figure 1 and Figure 2 , Figure 1 and Figure 2 Both show the detection results of solar cells produced after the screen is deformed under the prior art. During the printing process of the positive silver electrode of the solar cell, the screen will be deformed under the pressure of the scraper, causing the positive silver electrode actually printed on the silicon wafer to shift, and the positive silver secondary grid line and the laser doped area are prone to misalignment, which in turn leads to an increase in the black area at the edge of the solar cell, that is, the EL problem caused by the deformation of the screen.

[0049] like Figure 3 As shown, the comparative example of the present disclosure provides a solar cell 1000, which includes a substrate 1 and a laser doping pattern 2 formed on the substrate 1 by a laser doping process.

[0050] like Figure 4 As shown, the comparative example of the present disclosure provides a laser doping pattern 2, which can be formed on a silicon wafer. The laser doping pattern 2 can be Figure 3The figures in []. Exemplarily, the size of the silicon wafer is 182 * 182 mm. The secondary grid laser lines 204 with an even number of lines are parallel and evenly distributed on the silicon wafer in the left - right direction. The laser spot 40 width of each secondary grid laser line 204 is 100 μm. The distance between the two outermost secondary grid laser lines 204 is equal to the length of the innermost secondary grid laser line 204. The length of the secondary grid laser line 204 is 180 mm, and the DP value is 180 mm. Exemplarily, for the laser doping pattern 2 as a theoretical figure, its outer contour can be obtained based on the square formed by two preset end lines and the two outermost preset laser lines. For example, the outer contour of the laser doping pattern 2 is obtained by cutting off the four corners of the square pattern with a circle. The length of the two preset end lines is the DP value, and the laser spot 40 width of each preset end line is 100 μm. The two preset end lines and the two preset laser lines form a square pattern. The circle with a radius of 0.686 times the DP intersects with the above - mentioned square pattern to obtain the end line 201 and the secondary grid laser lines 204 inside the circle, and four chamfer lines 202 are obtained. The position of the center of the circle is the center position of the square. Some of the preset secondary grid laser lines of the preset laser doping pattern that are relatively close to the outer end can also be cut off to obtain multiple shorter secondary grid laser lines 204 that extend to the chamfer lines 202; and the uncut preset secondary grid laser lines are the longer secondary grid laser lines 204. The four chamfer lines 202 connect the end line 201 and the outermost secondary grid laser line 204 respectively. Four marking points 203 are located at the four corners. Each marking point 203 is composed of two mutually perpendicular laser lines, and the length of the laser lines is 600 μm. The distance between each marking point 203 and the nearest end line 201 is equal, and the distance between each marking point 203 and the nearest outermost secondary grid laser line 204 is equal. The distance between each marking point 203 and the nearest end line 201 and the distance between the marking point 203 and the nearest outermost secondary grid laser line 204 can be equal or not equal. In the up - down direction, the distance between two marking points 203 is 152 mm, and in the left - right direction, the distance between two marking points 203 is 157 mm.

[0051] Reference Figures 5 to 8 , the laser doping pattern 2 provided by the embodiment of the present disclosure includes two end lines 201, multiple secondary grid laser lines 204 and a first group of offset lines 310. Exemplarily, the secondary grid laser lines 204 are even - numbered and symmetrically arranged. For example, there are 160 or 176 secondary grid laser lines 204.

[0052] The two end lines 201 are arranged opposite to each other in the first direction. Exemplarily, the first direction is the X - axis direction, that is, the up - down direction. The two end lines 201 include an upper end line 201 and a lower end line 201.

[0053] A plurality of secondary grid laser lines 204 are arranged in parallel along a second direction and are located between two end lines 201. The second direction is perpendicular to the first direction. Exemplarily, the second direction is the Y-axis direction, i.e., the left-right direction. The plurality of secondary grid laser lines 204 have a middle position. The plurality of secondary grid laser lines 204 include an inner group of secondary grid laser lines 20 located at the middle position and a first group of secondary grid laser lines 21 located at the outermost ends along the second direction.

[0054] As Figure 5 shown, the inner group of secondary grid laser lines 20 includes four secondary grid laser lines 204, and actually may include more, such as 40 or 44. A plurality of secondary grid laser lines 204 in the inner group of secondary grid laser lines 20 can be symmetrically divided into inner left secondary grid laser lines and inner right secondary grid laser lines along the left-right direction. A plurality of secondary grid laser lines 204 in the outermost first group of secondary grid laser lines 21 can be symmetrically divided into first left secondary grid laser lines and first right secondary grid laser lines along the left-right direction.

[0055] The first group of offset lines 310 includes first offset lines 311 corresponding one-to-one to the secondary grid laser lines 204 in the first group of secondary grid laser lines 21. The first offset lines 311 are offset outward relative to the corresponding secondary grid laser lines 204, and the first offset lines 311 overlap or abut against the corresponding secondary grid laser lines 204. Exemplarily, the first group of offset lines 310 includes a first left offset line and a first right offset line symmetrically arranged along the left-right direction. The first offset line 311 can be referred to as the first left offset line or the first right offset line. The first left offset line is offset to the left relative to the first left secondary grid laser line, and the first left offset line overlaps or abuts against the first left secondary grid laser line. The first group of right offset lines is offset to the right relative to the first right secondary grid laser line, and the first right offset line overlaps or abuts against the first right secondary grid laser line.

[0056] In the laser doping pattern 2 provided by the embodiment of the present disclosure, the first left offset line overlaps or abuts against the first left secondary grid laser line to form an alignment region with a larger width than the original first left secondary grid laser line and an increased width relative to the left side. The first right offset line overlaps or abuts against the first right secondary grid laser line to form an alignment region with a larger width than the original first right secondary grid laser line and an increased width relative to the right side. Since the stencil can deform to the left and right sides during use, the positive silver electrode on the left side during printing is offset to the left and the positive silver electrode on the right side is offset to the right. Therefore, the first left offset line increases the alignment accuracy with the offset left positive silver electrode, and the first right offset line increases the alignment accuracy with the offset right positive silver electrode.

[0057] Exemplarily, the inner group of sub-grid laser lines 20 includes two inner left sub-grid laser lines adjacent to each other on the left and right and two inner right sub-grid laser lines adjacent to each other on the left and right. The outermost first group of sub-grid laser lines 21 includes two first left sub-grid laser lines adjacent to each other on the left and right and two first right sub-grid laser lines adjacent to each other on the left and right. The number of sub-grid laser lines 204 in the figure is an exemplary number, and actually more lines may be included.

[0058] The laser doping pattern 2 provided by the embodiment of the present disclosure increases the alignment accuracy with the misaligned positive silver electrode. The service life of the screen printing stencil is extended, and the production cost is reduced.

[0059] Reference Figure 6 , exemplarily, the laser doping pattern 2 is located on the silicon wafer. The width range of the laser spot 40 of the sub-grid laser line 204 is 80 - 120 μm. The length of the sub-grid laser line 204 is 1 - 5 mm shorter than the length of the silicon wafer. The distance between the outermost sub-grid laser lines 204 is called the DP value, and the size of the DP value is the same as the length of the sub-grid laser line 204, which is 1 - 5 mm shorter than the length of the silicon wafer.

[0060] Exemplarily, the width range of the laser spot 40 of the end line 201 is 80 - 120 μm. The length of the end line 201 is 5 - 20 mm smaller than the DP, and the distances from both ends of the end line 201 in the left - right direction to the edge of the silicon wafer are equal.

[0061] Exemplarily, the width range of the laser spot 40 of the first group of offset lines 310 is 80 - 120 μm.

[0062] Exemplarily, the width of the laser spot 40 of the end line 201, the width of the laser spot 40 of the sub-grid laser line 204, and the width of the laser spot 40 of the first group of offset lines 310 are the same.

[0063] Exemplarily, the distance between the sub-grid laser line 204 and the first offset line 311 ranges from 0 to the distance of 1 laser spot 40.

[0064] Reference Figures 5 to 8 , in some embodiments, the multiple sub-grid laser lines 204 further include a second group of sub-grid laser lines 22 located inside the first group of sub-grid laser lines 21. Exemplarily, the multiple sub-grid laser lines 204 in the second group of sub-grid laser lines 22 include second left sub-grid laser lines and second right sub-grid laser lines symmetrically arranged in the left - right direction. The second left sub-grid laser line is located between the first left sub-grid laser line and the inner left sub-grid laser line, and the second right sub-grid laser line is located between the first right sub-grid laser line and the inner right sub-grid laser line. The interval distances between the multiple sub-grid laser lines 204 are equal.

[0065] The laser doping pattern 2 further includes a second set of offset lines 320. The second set of offset lines 320 includes second offset lines 321 corresponding one-to-one to the sub-grid laser lines 204 in the second set of sub-grid laser lines 22. The second offset lines 321 are offset outward relative to the corresponding sub-grid laser lines 204, and the second offset lines 321 overlap or abut against the corresponding sub-grid laser lines 204. Exemplarily, the second set of offset lines 320 includes a second left offset line and a second right offset line symmetrically arranged in the left-right direction. Either the second left offset line or the second right offset line can be referred to as the second offset line 321. The second left offset line is offset to the left relative to the second left sub-grid laser line, and the second left offset line overlaps or abuts against the second left sub-grid laser line. The second right offset line is offset to the right relative to the second right sub-grid laser line, and the second right offset line overlaps or abuts against the second right sub-grid laser line.

[0066] With such an arrangement, corresponding offset lines are offset outside the multiple sets of sub-grid laser lines 204, and the multiple sets of sub-grid laser lines 204 overlap or abut against the corresponding offset lines, which can form multiple laser doping regions with an increasing width outward. The alignment accuracy between the multiple width-increased laser doping regions and the multiple offset positive silver electrodes is improved. The service life of the stencil is extended, and the production cost is reduced.

[0067] Exemplarily, the width range of the laser spot 40 of the second set of sub-grid laser lines 22 is 80 - 120 μm. The width range of the laser spot 40 of the second set of offset lines 320 is 80 - 120 μm.

[0068] Reference Figures 5 to 8 In some embodiments, the length of the second offset line 321 in the first direction is shorter than the length of the first offset line 311 in the first direction.

[0069] With such an arrangement, since the closer to the outer sub-grid laser line 204, the greater the deformation of the stencil and the more the offset amount. Therefore, setting the length of the first offset line 311 in the first direction to be greater than the length of the second offset line 321 in the first direction can reduce the offset error and improve the alignment accuracy.

[0070] Exemplarily, the length of the second left offset line in the up-down direction is shorter than the length of the first left offset line in the up-down direction.

[0071] Reference Figures 5 to 8, in some embodiments, the laser doping pattern 2 has eight regions equally divided along the second direction, namely the left first region S1, the left second region S2, the left third region S3, the left fourth region S4, the right fourth region S5, the right third region S6, the right second region S7, and the right first region S8. The inner group of sub-grid laser lines 20 are located in the left fourth region and the right fourth region, the first group of offset lines 310 are located in the left first region and the right first region, and the second group of offset lines 320 are located in the left second region and the right second region. The multiple sub-grid laser lines 204 further include a third group of sub-grid laser lines 23 located in the left third region and the right third region. The laser doping pattern 2 further includes a third group of offset lines 330, and the third group of offset lines 330 includes third offset lines 331 corresponding one-to-one to the sub-grid laser lines 204 in the third group of sub-grid laser lines 23. The third offset lines 331 are offset outward relative to the corresponding sub-grid laser lines 204, and the third offset lines 331 overlap or abut against the corresponding sub-grid laser lines 204.

[0072] Exemplarily, the laser doping pattern 2 from left to right is successively: the first left offset line and the first left sub-grid laser line in the left first region, the second left offset line and the second left sub-grid laser line in the left second region, the third left offset line and the third left sub-grid laser line 204 in the left third region, the inner left sub-grid laser line in the left fourth region, the inner right sub-grid laser line in the right fourth region, the third right sub-grid laser line and the third right offset line in the right third region, the second right sub-grid laser line and the second right offset line in the right second region, the first right sub-grid laser line and the first right offset line in the right first region.

[0073] With such a setting, the setting of the three groups of opposite offset lines can better improve the offset effect, reduce the offset error, and improve the alignment accuracy.

[0074] Reference Figures 3 to 8 , in some embodiments, the ratio of the length of the offset line in the first group of offset lines 310 to the length of the corresponding laser line is 1 / 2 to 1. The ratio of the length of the offset line in the second group of offset lines 320 to the length of the corresponding laser line is 1 / 4 to 1 / 2. The ratio of the length of the offset line in the third group of offset lines 330 to the length of the corresponding laser line is 1 / 8 to 1 / 4.

[0075] With such a setting, since the degree of deformation of the stencil gradually decreases from the laser line corresponding to the first group of offset lines 310 to the laser line corresponding to the third group of offset lines 330, the area of the laser doping region formed by the overlap or abutment of the sub-grid laser lines 204 and the corresponding offset lines also gradually decreases. Therefore, the length of the first group of offset lines 310 to the length of the third group of offset lines 330 gradually decreases. While improving the offset effect, the influence on the open circuit voltage of the silicon wafer test of the battery and the fill factor of the silicon wafer test is reduced.

[0076] Exemplarily, the length of the first offset line 311 is equal to the length of the first set of sub-grid laser lines 21. The length of the second offset line 321 is 1 / 2 of the length of the second set of sub-grid laser lines 22. The length of the third offset line 331 is 1 / 4 of the length of the third set of sub-grid laser lines 23.

[0077] Exemplarily, the length of the first offset line 311 is 1 / 2 of the length of the first set of sub-grid laser lines 21. The length of the second offset line 321 is 1 / 4 of the length of the second set of sub-grid laser lines 22. The length of the third offset line 331 is 1 / 8 of the length of the third set of sub-grid laser lines 23.

[0078] Referring again to Figures 3 to 8 , in some embodiments, it further includes a marking point 203 and a chamfer line 202. The marking point 203 is located between two end lines 201, and the marking point 203 is spaced apart from the sub-grid laser line 204. The chamfer line 202 is connected to the corresponding end line 201 and the outermost sub-grid laser line 204 among the plurality of sub-grid laser lines 204.

[0079] With such a setting, the connection of the chamfer line 202, the end line 201 and the outermost sub-grid laser line 204 defines the shape of the outermost end of the laser doping pattern 2. The marking point 203 defines the distance from the edge for positioning and increases the alignment accuracy.

[0080] Exemplarily, there are four marking points 203, which are distributed at the four corners and close to the chamfer line 202. The distance between each marking point 203 and the nearest end line 201 is equal, and the distance between each marking point 203 and the nearest first left sub-grid laser line or first right sub-grid laser line is equal. Each marking point 203 is composed of two mutually perpendicular laser lines, the directions of the laser lines are parallel to the four sides of the silicon wafer, and the length range of the laser lines is 500 - 1000 μm. The distance between the two marking points 203 in the up-down direction is 10 - 50 mm shorter than the length of the silicon wafer, and the distance between the two marking points 203 in the left-right direction is 10 - 50 mm shorter than the length of the silicon wafer. The lengths between the marking points in the two directions are not necessarily equal.

[0081] Exemplarily, a preset laser doping pattern is formed by a preset end line and a preset laser line, which has a square outer contour. Taking the center position of the square outer contour as the center of the circle, a circle with a radius of 0.686 times DP intersects with the above preset laser doping pattern, and then the four corners outside the circle are removed, and the end line 201 and the outermost sub-grid laser line 204 are connected to form four chamfer lines 202.

[0082] Referring to Figures 5 to 8 , in some embodiments, it further includes two end offset lines 340. The end offset lines 340 are offset inward relative to the corresponding end lines 201 and overlap or abut against the corresponding end lines 201.

[0083] Since the stencil is offset inward relative to the end line 201, the end offset line 340 is offset inward relative to the corresponding end line 201, and the laser doping region formed by overlapping or abutting against the corresponding end line 201 increases the alignment rate and improves the offset effect.

[0084] Exemplarily, the two end offset lines 340 are respectively an upper end offset line 340 and a lower end offset line 340. The upper end offset line 340 is located below the upper end line 201, while the lower end offset line 340 is located above the lower end line 201.

[0085] Exemplarily, the laser doping pattern 2 is composed of two end lines 201, multiple sub-grid laser lines 204, multiple sets of offset lines, marking points 203, chamfer lines 202, and end offset lines 340. The two end lines 201 are distributed in the up and down direction. The multiple sub-grid laser lines 204 are symmetrically arranged in groups in the left and right direction. The chamfer lines 202 are used to connect the end lines 201 and the outermost sub-grid laser lines 204. The multiple offset lines are offset outward relative to the corresponding sub-grid laser lines 204, and each offset line overlaps or abuts against the corresponding sub-grid laser line 204. The two end offset lines 340 are offset inward relative to the corresponding end lines 201, and each end offset line 340 overlaps or abuts against the corresponding end line 201. The laser doping pattern 2 is located on the silicon wafer.

[0086] Exemplarily, the first embodiment of the laser doping pattern 2 is as follows: The size of the silicon wafer is 182 * 182 mm. The even-numbered sub-grid laser lines 204 are parallel and evenly distributed on the silicon wafer in the left-right direction. The width of the laser spot 40 of each sub-grid laser line 204 is 100 μm. The distance between the two outermost sub-grid laser lines 204 is equal to the length of the innermost sub-grid laser line 204. The length of the sub-grid laser line 204 is 180 mm, and the DP value is 180 mm. Exemplarily, for the laser doping pattern 2 as a theoretical pattern, the outer contour can be obtained based on a square pattern formed by two preset end lines and the two outermost preset laser lines. The length of the two preset end lines is the DP value, and the width of the laser spot 40 of each preset end line is 100 μm. The two preset end lines and the two preset laser lines form a square pattern. A circle with a radius of 0.686 times the DP intersects the above square pattern to obtain the end line 201 and the sub-grid laser lines 204 within the circle, and four chamfer lines 202 are obtained. The position of the center of the circle is the center position of the square. The four chamfer lines 202 connect the end line 201 and the outermost sub-grid laser lines 204 respectively. Four marking points 203 are located at the four corners. Each marking point 203 is composed of two perpendicular laser lines, and the length of the laser lines is 600 μm. The distance between each marking point 203 and the nearest end line 201 is equal, and the distance between each marking point 203 and the nearest outermost sub-grid laser line 204 is equal. Along the up-down direction, the distance between two marking points 203 is 152 mm, and along the left-right direction, the distance between two marking points 203 is 157 mm. The sub-grid laser line 204 is evenly divided into eight regions. In the leftmost region, a first left offset line with a width of 100 μm, a length equal to that of the first left sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the first left sub-grid laser line is added to the left side of the first left sub-grid laser line. In the second left region, a second left offset line with a width of 100 μm, a length of 1 / 2 of the length of the second left sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the second left sub-grid laser line is added to the left side of the second left sub-grid laser line. In the third left region, a third left offset line with a width of 100 μm, a length of 1 / 4 of the length of the third left sub-grid laser line 204, and a distance of 0 - 1 laser spot 40 from the third left sub-grid laser line 204 is added to the left side of the third left sub-grid laser line 204. There is only an inner left sub-grid laser line in the fourth left region. There is only an inner right sub-grid laser line in the fourth right region. In the third right region, a third right offset line with a width of 100 μm, a length of 1 / 4 of the length of the third right sub-grid laser line 204, and a distance of 0 - 1 laser spot 40 from the third right sub-grid laser line 204 is added to the right side of the third right sub-grid laser line 204. In the second right region, a second right offset line with a width of 100 μm, a length of 1 / 2 of the length of the second right sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the second right sub-grid laser line is added to the right side of the second right sub-grid laser line.In the rightmost area, a first right offset line with a width of 100 μm is added to the right side of the first right sub-grid laser line. The length of the first right offset line is equal to that of the first right sub-grid laser line, and the distance between the first right offset line and the first right sub-grid laser line is 0 - 1 laser spot 40. A top-end offset line 340 with a width of 100 μm is added to the lower side of the top-end line 201. The length of the top-end offset line 340 is equal to that of the top-end line 201, and the distance between the top-end offset line 340 and the top-end line 201 is 0 - 1 laser spot 40. A bottom-end offset line 340 with a width of 100 μm is added to the upper side of the bottom-end line 201. The length of the bottom-end offset line 340 is equal to that of the bottom-end line 201, and the distance between the bottom-end offset line 340 and the bottom-end line 201 is 0 - 1 laser spot 40.

[0087] Reference Figures 9 to 11 , in some embodiments, it further includes a first group of additional offset lines 510 and a second group of additional offset lines 520. The first group of additional offset lines 510 includes first additional offset lines 511 that correspond one-to-one with the first offset lines 311 in the first group of offset lines 310. The first additional offset lines 511 are offset outward relative to the corresponding first offset lines 311, and the first additional offset lines 511 overlap or abut against the corresponding first offset lines 311. The first additional offset lines 511 have the same length as the corresponding first offset lines 311. The ratio of the length of the end offset line 340 to the span of the plurality of sub-grid laser lines 204 in the second direction is 1 / 2 to 1.

[0088] Exemplarily, the first additional offset lines 511 include first left additional offset lines and first right additional offset lines. The width range of the first additional offset lines 511 is 80 - 120 μm, and the length range of the first additional offset lines 511 is 1 / 2 - 1 times the length of the sub-grid laser lines 204.

[0089] Reference Figures 9 to 11 , in some embodiments, the second group of additional offset lines 520 includes second additional offset lines 521 that correspond one-to-one with the two end offset lines 340. The second additional offset lines 521 are offset inward relative to the corresponding end offset lines 340, and the second additional offset lines 521 overlap or abut against the corresponding end offset lines 340. The ratio of the length of the end offset line 340 to the span of the plurality of sub-grid laser lines 204 in the second direction is 1 / 2 to 1.

[0090] Exemplarily, the second additional offset lines 521 include second upper additional offset lines and second lower additional offset lines. The width range of the second additional offset lines 521 is 80 - 120 μm, and the length range of the second additional offset lines 521 is 1 / 2 - 1 times the length of the sub-grid laser lines 204.

[0091] Reference Figure 9, in some embodiments, the laser doping pattern 2 may be formed on a silicon wafer. The size of the silicon wafer is 182 * 182 mm. The sub-grid laser lines 204 with an even number of lines are parallel and evenly distributed on the silicon wafer in the left-right direction. The width of the laser spot 40 of each sub-grid laser line 204 is 100 μm. The distance between the two outermost sub-grid laser lines 204 is equal to the length of the innermost sub-grid laser line 204. The length of the sub-grid laser line 204 at the non-corner-cutting position is 180 mm, and the DP value is 180 mm. Exemplarily, for the laser doping pattern 2 as a theoretical pattern, the outer contour can be obtained based on a square pattern formed by two preset end lines and the two outermost preset laser lines. The length of the two preset end lines is the DP value, and the width of the laser spot 40 of each preset end line is 100 μm. The two preset end lines and the two preset laser lines form a square pattern. A circle with a radius of 0.686 times the DP intersects the above square pattern to obtain the end line 201 and the sub-grid laser lines 204 inside the circle, and four corner-cutting lines 202 are obtained. The position of the center of the circle is the center position of the square. The four corner-cutting lines 202 respectively connect the end line 201 and the outermost sub-grid laser line 204. Four marking points 203 are located at the four corners. Each marking point 203 is composed of two perpendicular laser lines, and the length of the laser lines is 600 μm. The distance between each marking point 203 and the nearest end line 201 is equal, and the distance between each marking point 203 and the nearest outermost sub-grid laser line 204 is equal. Along the up-down direction, the distance between two marking points 203 is 152 mm, and along the left-right direction, the distance between two marking points 203 is 157 mm. The sub-grid laser line 204 is divided into eight regions on average. In the leftmost region, a first left offset line with a width of 100 μm, a length of 1 / 2 of the length of the first left sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the first left sub-grid laser line is added to the left side of the first left sub-grid laser line; a first left additional offset line with a width of 100 μm, a length of 1 / 2 of the length of the first left sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the first left offset line is added to the left side of the first left offset line. In the second left region, a second left offset line with a width of 100 μm, a length of 1 / 2 of the length of the second left sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the second left sub-grid laser line is added to the left side of the second left sub-grid laser line. In the third left region, a third left offset line with a width of 100 μm, a length of 1 / 4 of the length of the third left sub-grid laser line 204, and a distance of 0 - 1 laser spot 40 from the third left sub-grid laser line 204 is added to the left side of the third left sub-grid laser line 204. There is only an inner left sub-grid laser line in the fourth left region. There is only an inner right sub-grid laser line in the fourth right region. In the third right region, a third right offset line with a width of 100 μm, a length of 1 / 4 of the length of the third right sub-grid laser line 204, and a distance of 0 - 1 laser spot 40 from the third right sub-grid laser line 204 is added to the right side of the third right sub-grid laser line 204.In the second right area, a second right offset line with a width of 100 μm, a length of 1 / 2 of the length of the second right sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the second right sub-grid laser line is added on the right side of the second right sub-grid laser line. In the first right area, a first right offset line with a width of 100 μm, a length of 1 / 2 of the length of the first right sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the first right sub-grid laser line is added on the right side of the first right sub-grid laser line; a first right additional offset line with a width of 100 μm, a length of 1 / 2 of the length of the first right sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the first right offset line is added on the right side of the first right offset line. A top-end offset line 340 with a width of 100 μm, a length of 1 / 2 of the length of the top-end line 201, and a distance of 0 - 1 laser spot 40 from the top-end line 201 is added on the lower side of the top-end line 201; a second top additional offset line with a width of 100 μm, a length of 1 / 2 of the length of the top-end line 201, and a distance of 0 - 1 laser spot 40 from the top-end offset line 340 is added on the lower side of the top-end offset line 340. A bottom-end offset line 340 with a width of 100 μm, a length of 1 / 2 of the length of the bottom-end line 201, and a distance of 0 - 1 laser spot 40 from the bottom-end line 201 is added on the upper side of the bottom-end line 201; a second bottom additional offset line with a width of 100 μm, a length of 1 / 2 of the length of the bottom-end line 201, and a distance of 0 - 1 laser spot 40 from the bottom-end offset line 340 is added on the upper side of the bottom-end offset line 340.

[0092] Reference Figure 10, in some embodiments, the laser doping pattern 2 can be formed on a silicon wafer. The size of the silicon wafer is 182 * 182 mm. The sub-grid laser lines 204 with an even number of lines are parallel and evenly distributed on the silicon wafer in the left-right direction. The width of the laser spot 40 of each sub-grid laser line 204 is 100 μm. The distance between the two outermost sub-grid laser lines 204 is equal to the length of the innermost sub-grid laser line 204. The length of the sub-grid laser line 204 is 180 mm, and the DP value is 180 mm. Exemplarily, for the laser doping pattern 2 as a theoretical pattern, the outer contour can be obtained based on a square pattern formed by two preset end lines and the two outermost preset laser lines. The length of the two preset end lines is the DP value, and the width of the laser spot 40 of each preset end line is 100 μm. The two preset end lines and the two preset laser lines form a square pattern. A circle with a radius of 0.686 times the DP intersects the above square pattern to obtain the end line 201 and the sub-grid laser lines 204 within the circle, and four chamfer lines 202 are obtained. The position of the center of the circle is the center position of the square. The four chamfer lines 202 respectively connect the end line 201 and the outermost sub-grid laser line 204. Four marking points 203 are located at the four corners. Each marking point 203 is composed of two mutually perpendicular laser lines, and the length of the laser lines is 600 μm. The distance between each marking point 203 and the nearest end line 201 is equal, and the distance between each marking point 203 and the nearest outermost sub-grid laser line 204 is equal. Along the up-down direction, the distance between two marking points 203 is 152 mm, and along the left-right direction, the distance between two marking points 203 is 157 mm. The sub-grid laser line 204 is divided into eight regions on average. In the leftmost region, a first left offset line with a width of 100 μm, a length of 1 / 2 of the length of the first left sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the first left sub-grid laser line is added to the left side of the first left sub-grid laser line; a first left additional offset line with a width of 100 μm, a length of 1 / 2 of the length of the first left sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the first left offset line is added to the left side of the first left offset line. In the second left region, a second left offset line with a width of 100 μm, a length of 1 / 4 of the length of the second left sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the second left sub-grid laser line is added to the left side of the second left sub-grid laser line. In the third left region, a third left offset line with a width of 100 μm, a length of 1 / 8 of the length of the third left sub-grid laser line 204, and a distance of 0 - 1 laser spot 40 from the third left sub-grid laser line 204 is added to the left side of the third left sub-grid laser line 204. There is only an inner left sub-grid laser line in the fourth left region. There is only an inner right sub-grid laser line in the fourth right region. In the third right region, a third right offset line with a width of 100 μm, a length of 1 / 8 of the length of the third right sub-grid laser line 204, and a distance of 0 - 1 laser spot 40 from the third right sub-grid laser line 204 is added to the right side of the third right sub-grid laser line 204.In the second right region, a second right offset line with a width of 100 μm, a length of 1 / 4 of the length of the second right sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the second right sub-grid laser line is added on the right side of the second right sub-grid laser line. In the first right region, a first right offset line with a width of 100 μm, a length of 1 / 2 of the length of the first right sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the first right sub-grid laser line is added on the right side of the first right sub-grid laser line; a first right additional offset line with a width of 100 μm, a length of 1 / 2 of the length of the first right sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the first right offset line is added on the right side of the first right offset line. A top end offset line 340 with a width of 100 μm, a length of 1 / 4 of the length of the top end line 201, and a distance of 0 - 1 laser spot 40 from the top end line 201 is added on the lower side of the top end line 201; a second upper additional offset line with a width of 100 μm, a length of 1 / 4 of the length of the top end line 201, and a distance of 0 - 1 laser spot 40 from the top end offset line 340 is added on the lower side of the top end offset line 340. A bottom end offset line 340 with a width of 100 μm, a length of 1 / 4 of the length of the bottom end line 201, and a distance of 0 - 1 laser spot 40 from the bottom end line 201 is added on the upper side of the bottom end line 201; a second lower additional offset line with a width of 100 μm, a length of 1 / 4 of the length of the bottom end line 201, and a distance of 0 - 1 laser spot 40 from the bottom end offset line 340 is added on the upper side of the bottom end offset line 340.

[0093] Reference Figure 11, in some embodiments, the laser doping pattern 2 may be formed on a silicon wafer. The size of the silicon wafer is 182 * 182 mm. The sub-grid laser lines 204 with an even number of lines are parallel and evenly distributed on the silicon wafer in the left-right direction. The width of the laser spot 40 of each sub-grid laser line 204 is 100 μm. The distance between the two outermost sub-grid laser lines 204 is equal to the length of the innermost sub-grid laser line 204. The length of the sub-grid laser line 204 is 180 mm, and the DP value is 180 mm. Exemplarily, for the laser doping pattern 2 as a theoretical pattern, the outer contour can be obtained based on a square pattern formed by two preset end lines and the two outermost preset laser lines. The length of the two preset end lines is the DP value, and the width of the laser spot 40 of each preset end line is 100 μm. The two preset end lines and the two preset laser lines form a square pattern. A circle with a radius of 0.686 times the DP intersects the above square pattern to obtain the end line 201 and the sub-grid laser lines 204 within the circle, and four chamfer lines 202 are obtained. The position of the center of the circle is the center position of the square. The four chamfer lines 202 respectively connect the end line 201 and the outermost sub-grid laser line 204. Four marking points 203 are located at the four corners. Each marking point 203 is composed of two perpendicular laser lines, and the length of the laser lines is 600 μm. The distance between each marking point 203 and the nearest end line 201 is equal, and the distance between each marking point 203 and the nearest outermost sub-grid laser line 204 is equal. Along the up-down direction, the distance between two marking points 203 is 152 mm, and along the left-right direction, the distance between two marking points 203 is 157 mm. The sub-grid laser line 204 is evenly divided into eight regions. In the leftmost region, a first left offset line with a width of 100 μm, a length equal to that of the first left sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the first left sub-grid laser line is added to the left side of the first left sub-grid laser line; a first left additional offset line with a width of 100 μm, a length equal to that of the first left sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the first left offset line is added to the left side of the first left offset line. In the second left region, a second left offset line with a width of 100 μm, a length of half of the length of the second left sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the second left sub-grid laser line is added to the left side of the second left sub-grid laser line. In the third left region, a third left offset line with a width of 100 μm, a length of 1 / 8 of the length of the third left sub-grid laser line 204, and a distance of 0 - 1 laser spot 40 from the third left sub-grid laser line 204 is added to the left side of the third left sub-grid laser line 204. Only the inner left sub-grid laser line exists in the fourth left region. Only the inner right sub-grid laser line exists in the fourth right region. In the third right region, a third right offset line with a width of 100 μm, a length of 1 / 8 of the length of the third right sub-grid laser line 204, and a distance of 0 - 1 laser spot 40 from the third right sub-grid laser line 204 is added to the right side of the third right sub-grid laser line 204.In the second right region, a second right offset line with a width of 100 μm, a length of 1 / 2 of the length of the second right sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the second right sub-grid laser line is added on the right side of the second right sub-grid laser line. In the first right region, a first right offset line with a width of 100 μm, a length equal to the length of the first right sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the first right sub-grid laser line is added on the right side of the first right sub-grid laser line; a first right additional offset line with a width of 100 μm, a length equal to the length of the first right sub-grid laser line, and a distance of 0 - 1 laser spot 40 from the first right offset line is added on the right side of the first right offset line. A top end offset line 340 with a width of 100 μm, a length equal to the length of the top end line 201, and a distance of 0 - 1 laser spot 40 from the top end line 201 is added on the lower side of the top end line 201; a second upper additional offset line with a width of 100 μm, a length equal to the length of the top end line 201, and a distance of 0 - 1 laser spot 40 from the top end offset line 340 is added on the lower side of the top end offset line 340. A bottom end offset line 340 with a width of 100 μm, a length equal to the length of the bottom end line 201, and a distance of 0 - 1 laser spot 40 from the bottom end line 201 is added on the upper side of the bottom end line 201; a second lower additional offset line with a width of 100 μm, a length equal to the length of the bottom end line 201, and a distance of 0 - 1 laser spot 40 from the bottom end offset line 340 is added on the upper side of the bottom end offset line 340.

[0094] With such a setting, the region formed by the additional offset line and the offset line further improves the alignment accuracy between the laser doping region and the front silver electrode, further extends the service life of the stencil, and reduces the production cost.

[0095] Reference Figures 5 to 11 Referring to

[0096] For the laser doping pattern 2 provided by the embodiment of the present disclosure, the partial offset line is offset inward relative to the corresponding end line 201 and overlaps or abuts against the corresponding end line 201, and the formed laser doping region improves the alignment accuracy with the front silver electrode that generates the offset. It extends the service life of the stencil and reduces the production cost.

[0097] The present disclosure embodiment also provides a solar cell 1000, which includes a substrate 1, the above-mentioned laser doping pattern 2, and an electrode line 6. The laser doping pattern 2 extends into the substrate 1. The electrode line 6 is stacked on the laser doping pattern 2.

[0098] For the solar cell 1000 provided by the present disclosure embodiment, the alignment accuracy rate of the laser doping pattern 2 is improved, the EL problem caused by printing deviation is reduced, the printing cost is lowered, and the printing efficiency is increased. At the same time, the quality of the solar cell is improved.

[0099] Reference Figure 6 , the laser spot 40 includes a first laser spot 401 and a second laser spot 402. Exemplarily, the first laser spot 401 is located inside the sub-grid laser line 204, and the second laser spot 402 is located inside the second offset line 321.

[0100] Reference Figure 8 , the sub-grid laser line 204 and the first offset line 311 of the laser doping pattern 2 extend into the substrate 1. The electrode line 6 is stacked either on the sub-grid laser line 204, or on the overlapping portion of the sub-grid laser line 204 and the first offset line 311, or on the first offset line 311. Exemplarily, the width of the electrode line 6 is about 30 μm.

[0101] In another aspect, the present disclosure embodiment provides a method for manufacturing the solar cell 1000. The above-mentioned laser doping pattern 2 is engraved on the substrate 1, and the screen plate is placed on the substrate 1 and aligned with the above-mentioned laser doping pattern 2 for printing the positive silver electrode.

[0102] In another aspect, the present disclosure embodiment provides a system for manufacturing the solar cell 1000. The system includes a laser doping device and a screen plate. The theoretical pattern of the above-mentioned laser doping pattern 2 is stored in the laser doping device. By using this device, the above-mentioned method can be executed to engrave the above-mentioned laser doping pattern 2 on the solar substrate 1. The screen plate is placed on the substrate 1 and aligned with the above-mentioned laser doping pattern 2 for printing the positive silver electrode. After that, the solar cell 1000 can be obtained through other processes.

[0103] Table 1 shows the comparison results of the average monthly service life of the screen plate and the monthly offset ratio between the comparative example and the examples. Among them, Figure 4 is shown as the comparative example, Figure 5 is shown as Example 1, Figure 9 is shown as Example 2, Figure 10 is shown as Example 3, Figure 11 is shown as Example 4.

[0104] Table 1

[0105] Average service life of monthly screen Monthly average offset ratio Comparative example 150,000 pieces / block 0.13％ Example 1 250,000 pieces / block 0.06％ Example 2 210,000 pieces / block 0.08％ Example 3 200,000 pieces / block 0.09％ Example 4 280,000 pieces / block 0.05％

[0106] As can be seen from Table 1, the average monthly service life of the screen plate in the comparative example is 150,000 sheets / block, and the average monthly offset ratio is 0.13%; the average monthly service life of the screen plate in Example 1 is 250,000 sheets / block, and the average monthly offset ratio is 0.06%, which is better than the comparative example; the average monthly service life of the screen plate in Example 2 is 210,000 sheets / block, and the average monthly offset ratio is 0.08%, which is better than the comparative example; the average monthly service life of the screen plate in Example 3 is 200,000 sheets / block, and the average monthly offset ratio is 0.09%, which is better than the comparative example; the average monthly service life of the screen plate in Example 4 is 280,000 sheets / block, and the average monthly offset ratio is 0.05%, which is better than the comparative example and better than the other 3 examples, and it is the best example. The present invention can increase the average monthly service life of the screen plate by 50,000 - 130,000 sheets / block and can reduce the offset ratio by 0.04% - 0.08%.

[0107] Table 2 shows the comparison results of the electrical properties of the solar cell 1000 between the comparative example and the four examples.

[0108] Table 2

[0109] Group Uoc (v) Isc (A) Rs (Ω) Rsh (Ω) FF (%) NCell Comparative example 0.6978 13.616 0.00155 998 81.32 23.40％ Example 1 0.6977 13.622 0.00156 1059 81.29 23.40％ Example 2 0.6977 13.623 0.00158 1000 81.27 23.40％ Example 3 0.6981 13.632 0.00162 997 81.19 23.40％ Example 4 0.6978 13.636 0.00163 1042 81.18 23.40％

[0110] Uoc represents the open-circuit voltage of the silicon wafer test, with the unit of V. Isc represents the short-circuit current of the silicon wafer test, with the unit of A. Rs represents the series resistance of the silicon wafer test, with the unit of Ω. Rsh represents the parallel resistance of the silicon wafer test, with the unit of Ω. FF represents the fill factor of the silicon wafer test, with the unit of %. NCell represents the conversion efficiency of the silicon wafer test, with the unit of %.

[0111] According to the data in the table, when the four examples are compared with the comparative example respectively, the short-circuit current of the silicon wafer test in the examples is on the high side, and the fill factor of the silicon wafer test is on the low side, but the conversion efficiency of the silicon wafer test is not affected.

[0112] The technical features of each of the above-disclosed examples can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above examples are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0113] In the above-disclosed examples, unless otherwise clearly specified and limited, the execution order of each step is not limited. For example, it can be executed in parallel or in different orders successively. The sub-steps of each step can also be executed alternately. Various forms of processes can be used, and steps can also be reordered, added, or deleted, as long as the desired results of the technical solutions provided by the embodiments of the present disclosure can be achieved. This is not limited herein.

[0114] The embodiments disclosed above merely represent several implementation manners of the present invention creation. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the patent protection scope of the invention creation. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention creation, several variations and improvements can still be made, and these all fall within the patent protection scope required by the present invention creation. Therefore, the patent protection scope of the present invention creation shall be subject to the appended claims.

Claims

1. A laser doping pattern for a solar cell, characterized in that, Comprising: Two end lines, oppositely arranged along a first direction; A plurality of sub-grid laser lines, arranged in parallel along a second direction and located between the two end lines, the second direction being perpendicular to the first direction, the plurality of sub-grid laser lines having a middle position, the plurality of sub-grid laser lines including an inner group of sub-grid laser lines located at the middle position and a first group of sub-grid laser lines located at the outermost ends along the second direction; And A first group of offset lines, including first offset lines corresponding one-to-one to the sub-grid laser lines in the first group of sub-grid laser lines, the first offset lines being offset outward relative to the corresponding sub-grid laser lines and overlapping or abutting against the corresponding sub-grid laser lines.

2. The laser doping pattern according to claim 1, wherein The plurality of sub-grid laser lines further includes a second group of sub-grid laser lines located inside the first group of sub-grid laser lines; The laser doping pattern further includes a second group of offset lines, the second group of offset lines including second offset lines corresponding one-to-one to the sub-grid laser lines in the second group of sub-grid laser lines, the second offset lines being offset outward relative to the corresponding sub-grid laser lines and overlapping or abutting against the corresponding sub-grid laser lines.

3. The laser doping pattern according to claim 2, wherein The length of the second offset line along the first direction is shorter than the length of the first offset line along the first direction.

4. The laser doping pattern according to claim 2, wherein, The laser doping pattern has eight regions equally divided along the second direction, namely a left one region, a left two region, a left three region, a left four region, a right four region, a right three region, a right two region and a right one region; The inner group of sub-grid laser lines is located in the left four region and the right four region, the first group of offset lines is located in the left one region and the right one region, and the second group of offset lines is located in the left two region and the right two region; The plurality of sub-grid laser lines further includes a third group of sub-grid laser lines located in the left three region and the right three region; The laser doping pattern further includes a third group of offset lines, the third group of offset lines including third offset lines corresponding one-to-one to the sub-grid laser lines in the third group of sub-grid laser lines, the third offset lines being offset outward relative to the corresponding sub-grid laser lines and overlapping or abutting against the corresponding sub-grid laser lines.

5. The laser doping pattern according to claim 4, wherein, The ratio of the length of the offset line in the first group of offset lines to the length of the corresponding laser line is from 1 / 2 to 1; The ratio of the length of the offset line in the second group of offset lines to the length of the corresponding laser line is from 1 / 4 to 1 / 2; The ratio of the length of the offset line in the third group of offset lines to the length of the corresponding laser line is from 1 / 8 to 1 / 4.

6. The laser doping pattern according to claim 1, wherein, Also including a marking point and a chamfering line; The marking point is located between the two end lines, and the marking point is spaced apart from the sub-grid laser lines; The chamfering line is connected to the corresponding end line and the outermost corresponding sub-grid laser line among the plurality of sub-grid laser lines.

7. The laser doping pattern according to claim 1, wherein Also including two end offset lines, the end offset lines being offset inward relative to the corresponding end lines and overlapping or abutting against the corresponding end lines.

8. The laser doping pattern according to claim 7, wherein, Also including a first group of additional offset lines and a second group of additional offset lines; The first set of additional offset lines includes first additional offset lines that correspond one-to-one with the first offset lines in the first set of offset lines. The first additional offset lines are offset outward relative to the corresponding first offset lines, and the first additional offset lines overlap or abut against the corresponding first offset lines. The first additional offset lines have the same length as the corresponding first offset lines. The second set of additional offset lines includes second additional offset lines that correspond one-to-one with the two end offset lines. The second additional offset lines are offset inward relative to the corresponding end offset lines, and the second additional offset lines overlap or abut against the corresponding end offset lines. The ratio of the length of the end offset lines to the span of the plurality of sub-grid laser lines in the second direction is 1 / 2 to 1.

9. A laser doping pattern for a solar cell, characterized in that, The laser doping pattern includes a plurality of laser lines, and the plurality of laser lines include: Two end lines, which are oppositely arranged in the first direction; A plurality of sub-grid laser lines, which are arranged side by side in the second direction and are located between the two end lines. The second direction is perpendicular to the first direction, and the plurality of sub-grid laser lines have a middle position; and Two end offset lines, which are offset inward relative to the corresponding end lines and overlap or abut against the corresponding end lines.

10. A solar cell, characterized in that, Comprising: A substrate; The laser doping pattern according to any one of claims 1 to 9, wherein the laser doping pattern extends into the substrate; And Electrode lines, which are stacked on the laser doping pattern.

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