Printing structure of solar cell and solar cell

Abstract

The utility model relates to a solar cell printing structure and a solar cell, the solar cell comprises a substrate and a main grid layer and an auxiliary grid layer which are arranged on the substrate, the printing structure comprises a plurality of alignment structures, each alignment structure comprises a first alignment point and a second alignment point, the first alignment point and the second alignment point are arranged on a target layer, and the first alignment point and the second alignment point are arranged on the target layer. The target layer comprises a main gate layer or an auxiliary gate layer; wherein the orthographic projection pattern position, on the substrate, of the second alignment point in the same alignment structure corresponds to the orthographic projection pattern position, on the substrate, of the first alignment point, the first alignment point is used for identifying the printing position of the main gate layer, and the second alignment point is used for identifying the printing position of the auxiliary gate layer. The alignment structure is arranged on the main grid layer or the auxiliary grid layer, so that the shading area of the alignment structure can be reduced, the optical absorption of the solar cell is improved, the conductivity of the grid layer is further enhanced, the utilization rate of metal slurry can be improved while the consumption of the metal slurry is reduced, and the overall working efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a printed structure of a solar cell and a solar cell. Background Art

[0002] In the manufacturing process of solar cells, alignment points are usually used to ensure the printing accuracy of metallization patterns. However, the setting of alignment points will affect the effective light-receiving area of ​​the cell surface and increase the consumption of metal paste. Utility Model Content

[0003] Based on this, it is necessary to provide a printing structure of a solar cell and a solar cell to address the problem that the setting of the alignment points in the prior art will affect the effective light-receiving area of ​​the cell surface and increase the consumption of metal paste.

[0004] In order to achieve the above object, the present application provides a printed structure of a solar cell, wherein the solar cell comprises a substrate and a main grid layer and a secondary grid layer arranged on the substrate, and the printed structure comprises:

[0005] A plurality of alignment structures, each of the alignment structures comprises a first alignment point and a second alignment point, the first alignment point and the second alignment point are both arranged in a target layer, and the target layer comprises the main gate layer or the auxiliary gate layer;

[0006] Among them, the orthographic projection graphic position of the second alignment point in the same alignment structure on the substrate corresponds to the orthographic projection graphic position of the first alignment point on the substrate, the first alignment point is used to identify the printing position of the main gate layer, and the second alignment point is used to identify the printing position of the secondary gate layer.

[0007] In one embodiment, the main grid layer includes a plurality of main grid lines and a plurality of harpoon structures, and the harpoon structure is provided at the end of each main grid line in the extension direction;

[0008] Wherein, the first alignment point and the second alignment point of the alignment structure are both arranged at the harpoon structure at the end of the main grid line on the edge area of ​​the substrate.

[0009] In one embodiment, the harpoon structure includes a pad electrically connected to the main grid line and a pair of harpoon lines, wherein the pair of harpoon lines are electrically connected to the pad and extend along the extension direction of the main grid line;

[0010] Wherein, the first alignment point and the second alignment point of the alignment structure are both arranged on at least one harpoon line of the harpoon structure.

[0011] In one embodiment, the harpoon structure includes a pad electrically connected to the main grid line, a pair of harpoon lines and a first overlapping gradient line, the pair of harpoon lines are electrically connected to the pad, and the first overlapping gradient line is provided at the junction of the pad and the secondary grid layer;

[0012] Wherein, the first alignment point and the second alignment point of the alignment structure are both arranged on the first overlapping gradient line.

[0013] In one embodiment, the secondary grid layer includes a plurality of secondary grid lines and a second overlapping gradient line, and the second overlapping gradient line is provided at the intersection of the main grid layer and the secondary grid line;

[0014] The first alignment point of the alignment structure is located on the second overlapping gradient line in an orthographic projection pattern on the substrate, and the second alignment point is located on the second overlapping gradient line.

[0015] In one embodiment, the auxiliary gate layer includes a plurality of auxiliary gate lines and anti-breaking gate lines, the anti-breaking gate lines are used to connect two adjacent auxiliary gate lines, and each of the alignment structures further includes:

[0016] A third pair of points, provided at the intersection of the anti-break gate line and the auxiliary gate line, the third pair of points being used to mark the position of the auxiliary gate line to be laser doped before printing;

[0017] The first pair of points is used to assist in positioning the printing position of the main grid layer according to the laser position of the third pair of points.

[0018] In one embodiment, both the first pair of sites and the second pair of sites are provided with at least a partial hole structure.

[0019] In one embodiment, the plurality of alignment structures are respectively disposed in at least three corner regions, and the corner regions are corners between two adjacent sides of the substrate.

[0020] In one of the embodiments, in each of the alignment structures, a center point of an orthographic projection pattern of the first alignment point on the substrate coincides with a center point of an orthographic projection pattern of the second alignment point on the substrate.

[0021] In one embodiment, a solar cell is provided, comprising the printed structure of the solar cell as described above.

[0022] The printing structure of the solar cell and the solar cell mentioned above include a plurality of alignment structures, each alignment structure includes a first alignment point and a second alignment point, the first alignment point is used to mark the printing position of the main grid layer, the second alignment point is used to mark the printing position of the auxiliary grid layer, the first alignment point and the second alignment point are both arranged in the main grid layer or the auxiliary grid layer, and the orthographic projection graphic position of the second alignment point on the substrate corresponds to the orthographic projection graphic position of the first alignment point on the substrate. On the one hand, by arranging the alignment structure in the main grid layer or the auxiliary grid layer, the shading area of ​​the alignment structure can be reduced, the optical absorption of the solar cell can be improved, and the photoelectric conversion efficiency of the solar cell can be further improved. On the other hand, by arranging the alignment structure in the main grid layer or the auxiliary grid layer, the conductive performance of the grid layer can be further enhanced, and the utilization rate of the metal slurry can be improved while reducing the consumption of the metal slurry, thereby improving the overall work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is one of the structural schematic diagrams of a printed structure of a solar cell provided in an embodiment;

[0025] Figure 2 This is a second structural schematic diagram of a printed structure of a solar cell provided in an embodiment;

[0026] Figure 3 The third structural schematic diagram of the printed structure of a solar cell provided in one embodiment;

[0027] Figure 4 This is a fourth structural schematic diagram of a printed structure of a solar cell provided in an embodiment;

[0028] Figure 5 The fifth structural schematic diagram of the printed structure of a solar cell provided in one embodiment;

[0029] 6(a) to (e) are schematic diagrams of overprint patterns formed by a first pair of dots and a second pair of dots provided in one embodiment.

[0030] Description of reference numerals:

[0031] Alignment structure: 100; first alignment point: 110; second alignment point: 120; third alignment point: 130; main grid line: 210; pad: 220; harpoon line: 230; first overlapping gradient line 240; secondary grid line: 310; second overlapping gradient line: 320; anti-break grid line: 330. DETAILED DESCRIPTION

[0032] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0034] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, in this specification, the term "and / or" includes any and all combinations of the relevant listed items.

[0035] In one embodiment, see Figure 1 , a printed structure of a solar cell is provided, the solar cell includes a substrate and a main grid layer and a secondary grid layer arranged on the substrate, and the printed structure includes: a plurality of alignment structures 100.

[0036] Each alignment structure 100 includes a first alignment point 110 and a second alignment point 120. The first alignment point 110 and the second alignment point 120 are both located in a target layer, and the target layer includes a main grid layer or a secondary grid layer. The orthographic projection graphic position of the second alignment point 120 in the same alignment structure 100 on the substrate corresponds to the orthographic projection graphic position of the first alignment point 110 on the substrate. The first alignment point 110 is used to mark the printing position of the main grid layer, and the second alignment point 120 is used to mark the printing position of the secondary grid layer. It should be noted that Figure 1 The alignment structure 100 is provided on the fish-fork line of the main grid layer as an example for illustration.

[0037] Among them, a solar cell is a device that converts light energy into electrical energy. Its working principle is to excite electrons in semiconductor materials through light irradiation, causing them to flow from the N-type side of the PN junction to the P-type side, thereby generating current for power supply. A solar cell is usually composed of a front electrode, a PN junction, a substrate, a back electrode and other elements. The substrate is an area that absorbs incident photons and generates photogenerated carriers. It may include one or more of monocrystalline silicon, polycrystalline silicon, and microcrystalline silicon. The light-receiving surface of the substrate is the front side, which refers to the side of the solar cell that receives light. The backlight side of the substrate is the back side that is arranged opposite to the light-receiving surface, which refers to the side of the solar cell that is away from the light. In some embodiments, the PN junction can be placed on the front side of the battery. For example, phosphorus elements can be diffused on a P-type silicon wafer to form an n+ / p-type solar cell, or boron elements can be injected into an N-type silicon wafer to form a p+ / n-type solar cell. When sunlight shines on the solar cell, photons will excite electrons in the silicon wafer and release them from atoms. Due to the existence of the PN junction, positively charged electrons are forced to move from the N-type side to the P-type side to form an electron flow, thereby generating a direct current in the battery.

[0038] Furthermore, the main grid layer and the auxiliary grid layer can be used as the front electrode structure for collecting charge carriers in the solar cell, wherein the main grid layer may include a main grid line, a welding point located on the main grid line, and a harpoon structure located at both ends of the main grid line, and the auxiliary grid layer may include an auxiliary grid line and an anti-breaking grid connecting two adjacent auxiliary grid lines, and the auxiliary grid line is used to collect photogenerated carriers, and the main grid line is used to collect the current collected by the auxiliary grid line and conduct it out.

[0039] Among them, when printing the front metal pattern, a distributed printing mode is usually adopted to print the main grid line and the auxiliary grid line, that is, since the morphology of the auxiliary grid line has a greater impact on the conversion efficiency of the battery cell, in order to maximize the current collection efficiency, the main grid line can be printed first, and then the auxiliary grid line can be printed, so as to avoid the adverse effects of the shape and conductivity of the auxiliary grid line caused by the subsequent sintering and curing steps of the main grid line due to the printing of the auxiliary grid line first. In the process of distributed printing, the first alignment point 110 needs to be printed while printing the main grid layer, and the second alignment point 120 needs to be printed while printing the auxiliary grid layer. The first alignment point 110 and the second alignment point 120 both play the role of auxiliary offset calibration during the printing process to ensure that the patterns of the main grid layer and the auxiliary grid layer are accurately overprinted at the expected position.

[0040] However, the first alignment site 110 and the second alignment site 120 are mainly used to assist in overprint calibration to improve the accuracy and consistency in the printing process to ensure the manufacturing quality of solar cells, but the alignment sites are not directly involved in other aspects, such as current collection and transmission, component certification, welding, and reliability.

[0041] In the related art, the positions of the alignment sites are usually distributed outside the metal pattern, which not only causes a waste of slurry, but also reduces the light-receiving area of ​​the solar cell surface, resulting in optical loss of the cell and reducing the photoelectric conversion efficiency of the solar cell. Based on this, this embodiment further optimizes the selection of the alignment sites, which can not only reduce the consumption of metal slurry, but also increase the effective light-receiving area of ​​the surface, so that the photoelectric conversion efficiency of the crystalline silicon solar cell is further improved.

[0042] The plurality of alignment structures 100 may be respectively distributed in at least three corner regions of the edge of the solar cell. Figure 1 An alignment structure 100 is shown on a corner area of ​​the surface of a solar cell. In some embodiments, the number of the plurality of alignment structures 100 can be set to four, and they are arranged one by one in the four corner areas of the solar cell. Furthermore, the first alignment point 110 can help the operator to accurately align the printed pattern of the main grid layer with their predetermined positions. Through a visual or automatic alignment system, the relevant printing equipment can be adjusted according to the position of the first alignment point 110 to ensure accurate printing of the main grid layer. The second alignment point 120 can also help the operator to accurately align the printed pattern of the secondary grid layer with their predetermined positions. Since the second alignment point 120 and the first alignment point 110 are overprinted, that is, the orthographic projection figure of the second alignment point 120 corresponds to the position of the orthographic projection figure of the first alignment point 110, for example, the first alignment point 110 and the second alignment point 120 can be arranged in a pattern of a circle enclosing a solid point or concentric rings. Figure 1 It is shown that the first alignment points 110 and the second alignment points 120 are overprinted and aligned using a circle-in-circle pattern, wherein the first alignment points 110 are large circles on the periphery and the second alignment points 120 are small circles on the inside.

[0043] Therefore, when the second alignment point 120 is used to align the printing position of the secondary grid layer, the overall offset of the overprint pattern composed of the second alignment point 120 and the first alignment point 110 can be determined. If the center points of the two alignment points are offset, fine-tuning of the position is required. If the center points of the two alignment points just coincide, subsequent printing is performed.

[0044] Furthermore, the positions of the first alignment point 110 and the second alignment point 120 can be set at the metallization pattern on the surface of the solar cell. The metallization pattern here can be understood as a printed pattern of the main grid layer or a printed pattern of the auxiliary grid layer. For example, when the main grid layer includes a main grid line, a harpoon structure and a first overlapping gradient line 240, and the auxiliary grid layer includes an auxiliary grid line and a second overlapping gradient line, the first overlapping gradient line 240 is set at the connection between the harpoon structure and the auxiliary grid line, and the second overlapping gradient line is set at the connection between the main grid line and the auxiliary grid line. Therefore, the positions of the first alignment point 110 and the second alignment point 120 can be set in the harpoon structure or the first overlapping gradient line 240 (for example Figure 1 The alignment structure 100 is shown as being arranged in the harpoon line of the harpoon structure), that is, the positions of the first alignment point 110 and the second alignment point 120 can be designed in the main grid layer. In addition, the positions of the first alignment point 110 and the second alignment point 120 can also be arranged in the second overlap gradient line, that is, the positions of the first alignment point 110 and the second alignment point 120 can be designed in the secondary grid layer.

[0045] Therefore, by designing the alignment structure 100 in the metal pattern of the main grid layer or the auxiliary grid layer, on the one hand, it is possible to avoid the generation of an additional shading area, thereby reducing the blocking of the incident light by the alignment structure 100, and further improving the photoelectric conversion efficiency of the solar cell. On the other hand, the alignment structure 100 can not only provide a printing positioning function, but also help to improve the conductive performance of the metal pattern, thereby improving the utilization rate of the metal paste used for printing the alignment structure 100; on the third hand, compared with the related art of designing the alignment point outside the metal pattern, which makes it easy for the alignment point to be detected by the human eye, the alignment structure 100 is set in the main grid layer or the auxiliary grid layer in this embodiment, which can enhance the aesthetics of the solar cell.

[0046] Optionally, since the size of the metal pattern of the main gate layer or the auxiliary gate layer is small, when the alignment structure 100 is designed in the metal pattern of the main gate layer or the auxiliary gate layer, in order to improve the recognition of the alignment structure 100 and improve the positioning accuracy of printing, the number of the alignment structures 100 can be set to multiple in the corner area of ​​a substrate, for example Figure 1 The case where the number of the alignment structures 100 is set to two in one corner region is shown.

[0047] The printing structure of the solar cell provided in the present embodiment includes a plurality of alignment structures 100, each alignment structure 100 includes a first alignment point 110 and a second alignment point 120, the first alignment point 110 is used to mark the printing position of the main grid layer, the second alignment point 120 is used to mark the printing position of the auxiliary grid layer, the first alignment point 110 and the second alignment point 120 are both arranged in the main grid layer or the auxiliary grid layer, and the orthographic projection graphic position of the second alignment point 120 on the substrate corresponds to the orthographic projection graphic position of the first alignment point 110 on the substrate. On the one hand, arranging the alignment structure 100 in the main grid layer or the auxiliary grid layer can reduce the shading area of ​​the alignment structure 100, improve the optical absorption of the solar cell, and further improve the photoelectric conversion efficiency of the solar cell. On the other hand, arranging the alignment structure 100 in the main grid layer or the auxiliary grid layer can further enhance the conductive performance of the grid layer, and can improve the utilization rate of the metal slurry while reducing the consumption of the metal slurry, thereby improving the overall work efficiency.

[0048] In one embodiment, the main grid layer includes a plurality of main grid lines and a plurality of harpoon structures, and a harpoon structure is provided at the end of each main grid line in the extension direction. The first alignment point and the second alignment point of the alignment structure are both provided at the harpoon structure at the end of the main grid line on the edge area of ​​the substrate.

[0049] Among them, multiple main grid lines can be arranged at intervals in a direction perpendicular to their extension direction. The main grid lines can guide the photogenerated carriers collected by the auxiliary grid layer to the welding strip, so the main grid lines play a conductive role and a role in carrying and connecting with the welding strip. For each main grid line, the two ends of the main grid line in the extension direction are respectively provided with a harpoon structure, and the harpoon structure can effectively collect the current at the edge of the battery cell to reduce the loss, thereby improving the current collection capacity of the solar cell. Based on the fact that multiple alignment structures are respectively distributed in the edge area of ​​the solar cell, the positions of the multiple alignment structures can be respectively designed in the harpoon structure at the end of the main grid line at the edge of the substrate. For example, when the number of the multiple alignment structures is four, the positions of the four alignment structures can be respectively set in four harpoon structures, and the four harpoon structures are respectively located at the two ends of the two main grid lines at the edge. In this way, the alignment structure is designed in the metal pattern of the main grid layer, which can not only reduce the consumption of metal slurry, but also increase the effective light receiving area of ​​the battery surface.

[0050] In one embodiment, Figure 2 As shown, the harpoon structure includes a pad 220 electrically connected to the main grid line 210 and a pair of harpoon lines 230, wherein the pair of harpoon lines 230 are electrically connected to the pad 220 and extend along the extension direction of the main grid line 210. The first alignment point 110 and the second alignment point 120 of the alignment structure 100 are both arranged on at least one harpoon line 230 of the harpoon structure.

[0051] Among them, it can be understood that in production applications, multiple solar cells are usually welded together for external output, so each main grid line 210 can be distributed with welding points for welding, and then the welding points in multiple solar cells are all welded together using welding strips to form electrical contact. The welding points set at both ends of the main grid line 210 in the extension direction are used as the pads 220 in this embodiment, and the two ends of the main grid line 210 and the paired harpoon lines 230 are respectively connected in the extension direction. The paired harpoon lines 230 can collect the current at the edge of the battery. The setting of the pads 220 facilitates the connection between the main grid line 210, the auxiliary grid line and the harpoon line 230, and ensures the firmness of the connection position. Therefore, the position of the alignment structure 100 can be set to the harpoon line 230 filled with metal slurry to avoid generating additional shading area, reduce the blocking of the incident light by the alignment structure 100, further improve the photoelectric conversion efficiency of the solar cell, and help to improve the conductive performance of the harpoon line 230, thereby improving the utilization rate of the metal slurry used in the printed alignment structure 100.

[0052] Among them, in a corner area of ​​the substrate, the number of alignment structures 100 can be one or more. Since the size of the harpoon line 230 is small, in order to improve the positioning accuracy of the first alignment point 110 and the second alignment point 120 during the printing process, the alignment structure 100 in the same corner area can be set to multiple to achieve easier alignment marking. For example, when the alignment structure 100 in the same corner area is set to two, and the multiple alignment structures 100 are correspondingly distributed in four edge areas, the number of alignment structures 100 in the entire battery cell graphic area is eight.

[0053] In one embodiment, Figure 3 As shown, the harpoon structure includes a pad 220 electrically connected to the main grid line 210, a pair of harpoon lines 230 and a first overlapping gradient line 240, wherein the pair of harpoon lines 230 is electrically connected to the pad 220, and the first overlapping gradient line 240 is arranged at the intersection of the pad 220 and the secondary grid layer. The first alignment point 110 and the second alignment point 120 of the alignment structure are both arranged at the first overlapping gradient line 240.

[0054] Among them, the auxiliary grid layer may include multiple auxiliary grid lines 310, and the multiple auxiliary grid lines 310 are arranged at intervals in a direction perpendicular to the extension direction of the main grid line 210. The size of the auxiliary grid line 310 is much thinner than the main grid line 210. The auxiliary grid line 310 is used to collect carriers generated by the solar cell. The auxiliary grid line 310 intersects with the main grid line 210 to transfer the carriers to the main grid line 210. A first overlapping gradient line 240 is arranged at the intersection of the pad 220 connected to the harpoon line 230 and the secondary grid line 310 in the secondary grid layer. The size of the first overlapping gradient line 240 in the extension direction of the main grid line 210 is larger than the size of the secondary grid line 310, and the size of the first overlapping gradient line 240 in the extension direction of the main grid line 210 gradually increases along the direction approaching the pad 220. The first overlapping gradient line 240 serves as the overlapping portion between the pad 220 and the correspondingly connected secondary grid line 310, which can improve the reliability of the connection at the intersection of the pad 220 and the secondary grid line 310, and avoid the problem of lack of connectivity between the secondary grid line 310 and the pad 220.

[0055] Therefore, the positions of the first alignment point 110 and the second alignment point 120 of the alignment structure can be set at the first overlapping gradient line 240 filled with metal paste to avoid generating additional shading area, reduce the blocking of incident light by the alignment structure, further improve the photoelectric conversion efficiency of the solar cell, and help to improve the conductivity of the intersection of the sub-gate layer and the pad 220, thereby improving the utilization rate of the metal paste used for the printed alignment structure.

[0056] Optionally, since the size of the first overlapping gradient line 240 is small, in order to improve the positioning accuracy of the first alignment point 110 and the second alignment point 120 during the printing process, the alignment structure of the same corner area can be set to multiple to achieve easier alignment marking, for example Figure 3 When two alignment structures are provided in the same corner region, the two alignment structures correspond to the two first overlapping gradient lines 240 provided on the left and right sides of the pad 220 , respectively.

[0057] In one embodiment, Figure 4 As shown, the secondary gate layer includes a plurality of secondary gate lines 310 and a second overlapping gradient line 320, and the second overlapping gradient line 320 is arranged at the intersection of the main gate layer and the secondary gate line 310. The orthographic projection pattern of the first alignment point 110 of the alignment structure on the substrate is arranged on the second overlapping gradient line 320, and the second alignment point 120 is arranged on the second overlapping gradient line 320.

[0058] Among them, a plurality of auxiliary grid lines 310 are arranged at intervals along the extension direction of the main grid line 210, so that the main grid line 210 and the auxiliary grid line 310 form a crisscross arrangement structure, and the main grid line 210 and the auxiliary grid line 310 are perpendicular to each other to reduce the transmission distance of the carrier, thereby improving the current transmission efficiency. The auxiliary grid line 310 is used to collect the photocurrent converted by the solar cell, and collect the collected photocurrent to the main grid line 210, and the main grid line 210 then conducts the current to the connected welding strip through the welding point thereon.

[0059] Furthermore, a second overlapping gradient line 320 is provided at the intersection of the secondary grid line 310 and the main grid line 210 in the main grid layer. The size of the second overlapping gradient line 320 in the extension direction of the main grid line 210 is larger than the size of the secondary grid line 310, and the size of the second overlapping gradient line 320 in the extension direction of the main grid line 210 gradually increases in the direction approaching the main grid line 210. The second overlapping gradient line 320 serves as the overlapping portion between the secondary grid line 310 and the correspondingly connected main grid line 210, which can improve the reliability of the connection at the intersection of the main grid line 210 and the secondary grid line 310, and avoid the problem of the main grid line 210 and the secondary grid line 310 being unable to connect due to printing errors.

[0060] Therefore, the position of the alignment structure can be set at the second overlapping gradient line 320 filled with metal paste, wherein, based on the distributed printing pattern of the main grid layer and the sub-grid layer, the position of the first alignment point 110 used to identify the printing position of the main grid layer is located on the second overlapping gradient line 320 in the positive projection pattern on the substrate, and the second alignment point 120 used to identify the printing position of the sub-grid layer is set on the second overlapping gradient line 320, thereby avoiding the position of the alignment structure to generate additional shading area, reducing the alignment structure's blocking of incident light, and further improving the photoelectric conversion efficiency of the solar cell, and helping to improve the conductive performance at the intersection of the sub-grid line 310 and the main grid line 210, thereby improving the utilization rate of the metal paste used for printing the alignment structure.

[0061] Optionally, since the size of the second overlapping gradient line 320 is small, in order to improve the positioning accuracy of the first alignment point 110 and the second alignment point 120 during the printing process, the alignment structure of the same corner area can be set to multiple to achieve easier alignment marking, for example Figure 4 It is shown that when two alignment structures are provided in the same corner area, the two alignment structures are respectively provided at positions of the second overlapping gradient line 320 close to the main grid line 210 .

[0062] In one embodiment, the secondary grid layer includes a plurality of secondary grid lines 310 and anti-break grid lines 330, the anti-break grid lines 330 are used to connect two adjacent secondary grid lines 310, and each alignment structure further includes: a third alignment point 130, the third alignment point 130 is arranged at the intersection of the anti-break grid line 330 and the secondary grid line 310, and the third alignment point 130 is used to mark the position of the secondary grid line 310 to be laser doped before printing. Among them, the first alignment point 110 is used to assist in positioning the printing position of the main grid layer according to the laser position of the third alignment point 130.

[0063] Among them, SE (Selective emitter) laser doping technology is to perform laser heavy doping in the area where the secondary grid line 310 contacts the substrate to increase the doping concentration in the area where the secondary grid line 310 contacts. After the secondary grid line 310 area passes through the SE laser, the square resistance of this area is lower than that of other places, which is conducive to the collection of carriers and the reduction of surface recombination losses. When the secondary grid line 310 area is laser doped, it is necessary to use a laser to mark as the third pair of points 130 to assist in calibrating the position accuracy of the secondary grid line 310 during laser doping. In the related art, the third pair of points 130 used to mark the laser doping position of the secondary grid line 310 is usually located outside the printed metal pattern, which not only causes optical loss in the cell, but also causes damage to the surface of the cell.

[0064] Therefore, in this embodiment, the third alignment point 130 is set at the metallized pattern on the surface of the solar cell. The metallized pattern here can be understood as the connection between the anti-break grid line 330 and the auxiliary grid line 310, wherein the anti-break grid line 330 can effectively collect photogenerated current when there are multiple breakages in the same auxiliary grid line 310 to ensure the current collection efficiency. Therefore, the third alignment point 130 is designed at the connection between the anti-break grid line 330 and the auxiliary grid line 310 to avoid the laser marking of the third alignment point 130 from generating additional shading area, thereby reducing the blocking of the incident light by the alignment structure, further improving the photoelectric conversion efficiency of the solar cell, and further reducing the damage caused by the laser marking to the solar cell surface.

[0065] It should be noted that the position of the third pair of sites can be arranged and combined with the positions of the first pair of sites and the second pair of sites provided in the above embodiment, for example:

[0066] In the first case, for example Figure 5 As shown, the first pair of points 110 and the second pair of points 120 are arranged on the harpoon line 230 , and the third pair of points 130 is arranged at the intersection of the anti-break grid line 330 and the secondary grid line 310 .

[0067] In the second case, the first pair of points and the second pair of points are set at the first overlapping gradient line, and the third pair of points is set at the intersection of the anti-break grid line and the auxiliary grid line. Figure 5The first overlapping gradient 240 is disposed at the intersection of the pad 220 and the secondary gate line 310 .

[0068] In the third case, the first pair of points and the second pair of points are set at the second overlapping gradient line, and the third pair of points is set at the intersection of the anti-break grid line and the auxiliary grid line. Figure 5 The second overlapping gradient line 320 is disposed at the intersection of the main grid line 210 and the secondary grid line 310 .

[0069] Optionally, the pattern shape of the third pair of sites 130 may be a T-shape (eg Figure 5 As shown), the laser marking area can be reduced to avoid increasing the optical shielding of the solar cell.

[0070] In one embodiment, in each alignment structure, the center point of the orthographic projection pattern of the first alignment point on the substrate coincides with the center point of the orthographic projection pattern of the second alignment point on the substrate. Wherein, the normal alignment process can be: the third alignment point obtained by SE laser is used to perform laser heavy doping on the secondary grid line area, and then the main grid layer is printed first, for example, it can be determined whether the offset between the position of the third alignment point and the position of the first alignment point reaches the standard for printing the main grid layer, if it reaches, then the main grid layer is printed. Then continue to print the secondary grid layer, and it can be determined whether the secondary grid layer is aligned according to whether the center point of the second alignment point in each alignment structure coincides with the center point of the first alignment point. If the center point of the second alignment point of each alignment structure coincides with the center point of the first alignment point, then the secondary grid layer is printed. If the center point of the second alignment point of each alignment structure does not coincide with the center point of the first alignment point, then the position is fine-tuned until the two coincide, thereby using the method of graphic overprinting between the second alignment point and the first alignment point to achieve overall judgment of the offset of the metallized graphic.

[0071] Optionally, in the same alignment structure, the overprint pattern of the first alignment point and the second alignment point can be a solid circle within a solid circle (for example, the first alignment point uses a large circle on the outside and the second alignment point uses a small circle on the inside), a half-shaped solid circle within a solid circle, a solid circle within a solid circle, etc. For examples, please refer to Figure 6(a) to Figure 6(e), the schematic diagram of FIG6(a) is a pattern of a large circle inside a small circle for the first alignment point 110 and the second alignment point 120. The schematic diagram of FIG6(b) is another overprint pattern of the first alignment point 110 and the second alignment point 120, the first alignment point 110 can be a large circle + two acute triangles in the vertical direction, and the second alignment point 120 can be a small circle + two acute triangles in the horizontal direction. FIG6(c) shows that the first alignment point 110 is a half-truncated solid circle + four small right-angled triangles on the periphery, and the second alignment point 120 is a half-truncated solid circle + four small right-angled triangles on the periphery, thereby overprinting the pattern on the far right of FIG6(c), wherein the formation of FIG6(d) and FIG6(e) can refer to the description of FIG6(c). Therefore, based on the degree of overlap between the center point of the first alignment point pattern and the center point of the second alignment point pattern, the accuracy of the gate layer printing can be effectively judged.

[0072] In one embodiment, the first alignment point and the second alignment point are both provided with at least a partial hole structure. Among them, since the first alignment point and the second alignment point are patterns filled with metal paste, in order to reduce costs, the patterns of the first alignment point and the second alignment point can be set to be partially hollowed out, that is, there is at least a partial area where the paste is not printed, thereby saving production costs while assisting in printing the grid line layer.

[0073] In one embodiment, a plurality of alignment structures are respectively arranged at at least three corner regions, and the corner regions are the corners between two adjacent sides of the substrate. That is, the alignment structures are respectively arranged at at least three corners of the surface of the solar cell, which is conducive to fully grasping the alignment structures in different corner regions during the positioning process, so as to locate the center of the cell and the distance from the alignment structure to the edge of the cell, and then the subsequent printing. In other embodiments, four alignment structures can be respectively arranged at the four corner regions of the substrate for aesthetics.

[0074] In one embodiment, a solar cell is provided, comprising the printed structure of the solar cell provided in the above embodiment. It can be understood that since the solar cell uses the printed structure of the solar cell provided in the above embodiment, when the performance of the printed structure of the solar cell is higher than that of the traditional printed structure, the corresponding working performance of the solar cell is also improved accordingly.

[0075] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", "ideal embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0076] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features of the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A printed structure of a solar cell, characterized in that: The solar cell comprises a substrate and a main grid layer and a secondary grid layer arranged on the substrate, and the printed structure comprises: A plurality of alignment structures, each of the alignment structures comprises a first alignment point and a second alignment point, the first alignment point and the second alignment point are both arranged in a target layer, and the target layer comprises the main gate layer or the auxiliary gate layer; Among them, the orthographic projection graphic position of the second alignment point in the same alignment structure on the substrate corresponds to the orthographic projection graphic position of the first alignment point on the substrate, the first alignment point is used to identify the printing position of the main gate layer, and the second alignment point is used to identify the printing position of the secondary gate layer.

2. The printed structure of solar cell according to claim 1, characterized in that: The main grid layer includes a plurality of main grid lines and a plurality of harpoon structures, and the harpoon structure is provided at the end of each main grid line in the extension direction; Wherein, the first alignment point and the second alignment point of the alignment structure are both arranged at the harpoon structure at the end of the main grid line on the edge area of ​​the substrate.

3. The printed structure of solar cell according to claim 2, characterized in that: The harpoon structure comprises a pad electrically connected to the main grid line and a pair of harpoon lines, wherein the pair of harpoon lines are electrically connected to the pad and extend along the extension direction of the main grid line; Wherein, the first alignment point and the second alignment point of the alignment structure are both arranged on at least one harpoon line of the harpoon structure.

4. The printed structure of a solar cell according to claim 2, characterized in that: The harpoon structure comprises a pad electrically connected to the main grid line, a pair of harpoon lines and a first overlapping gradient line, wherein the pair of harpoon lines is electrically connected to the pad, and the first overlapping gradient line is arranged at the intersection of the pad and the auxiliary grid layer; Wherein, the first alignment point and the second alignment point of the alignment structure are both arranged on the first overlapping gradient line.

5. The printed structure of solar cell according to claim 1, characterized in that: The secondary grid layer includes a plurality of secondary grid lines and a second overlapping gradient line, wherein the second overlapping gradient line is arranged at the intersection of the main grid layer and the secondary grid line; The first alignment point of the alignment structure is located on the second overlapping gradient line in an orthographic projection pattern on the substrate, and the second alignment point is located on the second overlapping gradient line.

6. The printed structure of a solar cell according to any one of claims 2 to 5, characterized in that: The auxiliary gate layer includes a plurality of auxiliary gate lines and an anti-breaking gate line, wherein the anti-breaking gate line is used to connect two adjacent auxiliary gate lines, and each of the alignment structures further includes: A third pair of points, provided at the intersection of the anti-break gate line and the auxiliary gate line, the third pair of points being used to mark the position of the auxiliary gate line to be laser doped before printing; The first pair of points is used to assist in positioning the printing position of the main grid layer according to the laser position of the third pair of points.

7. The printed structure of a solar cell according to any one of claims 1 to 5, characterized in that: The first pair of sites and the second pair of sites are both provided with at least a partial hole structure.

8. The printed structure of solar cell according to claim 1, characterized in that: The plurality of alignment structures are respectively disposed in at least three corner regions, and the corner regions are corners between two adjacent sides of the substrate.

9. The printed structure of solar cell according to claim 1, characterized in that: In each of the alignment structures, a center point of an orthographic projection pattern of the first alignment point on the substrate coincides with a center point of an orthographic projection pattern of the second alignment point on the substrate.

10. A solar cell, characterized in that: A printed structure comprising a solar cell as claimed in any one of claims 1 to 9.

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