Back-contact solar cell modules and their fabrication methods, photovoltaic power generation systems

Abstract

This invention discloses a back-contact solar cell module and its fabrication method, as well as a photovoltaic power generation system, relating to the field of solar cell technology. The back-contact solar cell module uses conventional back-contact cells, with each cell divided into two halves serving as a back-contact cell segment. This allows for the construction of a staggered cell array using the main back-contact cell and the back-contact cell segments, reducing losses during half-cell shading and effectively mitigating hot spot effects, thus preventing excessive temperature rise in the module. Simultaneously, eliminating the rectangular transition area reduces the silicon wafer cost of the module. The conductive lines on the PCB compensate for the lateral misalignment of the dissimilar electrodes in the staggered cell array, ensuring a uniform spacing of 2d between the main back-contact cells and between the main back-contact cell and the back-contact cell segment. This reduces the complexity of the wiring process and improves the consistency of the module's electrical performance.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and in particular to a back-contact solar cell module and its preparation method, as well as a photovoltaic power generation system. Background Technology

[0002] Back-contact solar cells have no grid lines on their front side (the light-receiving side), which greatly reduces optical loss caused by grid line shading and also provides better aesthetics.

[0003] The inventors are aware that some photovoltaic (PV) power generation systems use bypass diodes connected in parallel to all or a designated portion of the solar cells when setting up the circuit loop to reduce shading losses caused by hot spots or shadows. However, the diode strings in a PV power generation system require a certain amount of space, which, without changing the cell layout, leads to an increase in the size of the PV power generation system and a decrease in its efficiency. Patent ZL202411514123.7 discloses a back-contact solar cell module where the back-contact cells are arranged in a staggered array, which avoids the use of bypass diodes and effectively reduces hot spots and power losses caused by shading.

[0004] However, this technology has the following drawbacks: The staggered array arrangement leads to lateral misalignment of adjacent opposite-shaped electrodes in adjacent cell rows. Conventional welding electrodes cannot be bent, failing to meet the connection requirements of the cell array. Therefore, a rectangular transition area needs to be added to the back-contact cell structure, and the spacing between cells and between cell sections within the array needs to be adjusted to eliminate this lateral misalignment. However, this increases the cost of silicon wafers. Furthermore, the inconsistent spacing between cells and between cell sections not only complicates the process but also reduces the consistency of the electrical performance of the photovoltaic power generation system. Summary of the Invention

[0005] The purpose of this invention is to provide a back-contact solar cell module and its preparation method, as well as a photovoltaic power generation system. The invention uses PCB conductive lines to compensate for the lateral misalignment of the heterogeneous electrodes in the misaligned array of back-contact solar cells, thereby unifying the spacing between any two adjacent solar cell bodies and between any adjacent solar cell bodies and solar cell sections in the misaligned array of back-contact solar cells. This reduces the complexity of the manufacturing process and ensures the consistency of the electrical performance of the photovoltaic power generation system, thus solving the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] On one hand, the present invention provides a back-contact solar cell module, including a back-contact cell array and a PCB backplane, wherein:

[0008] The back contact solar cell array includes M first cell row units and M second cell row units arranged alternately along the longitudinal direction. Each first cell row unit includes N back contact solar cell bodies arranged laterally, and the lateral spacing between any two adjacent back contact solar cell bodies is a preset distance 2d. Each back contact solar cell body includes positive electrode main grid lines and negative electrode main grid lines alternately arranged laterally on the backlight surface of the back contact solar cell body, and the lateral spacing between any positive electrode main grid line and an adjacent negative electrode main grid line is a preset distance w. Each of the second battery row units includes N-1 back contact battery cell bodies arranged continuously in the horizontal direction, and back contact battery cell portions respectively arranged at both ends of the N-1 back contact battery cell bodies. The horizontal spacing between any two adjacent back contact battery cell bodies, and the horizontal spacing between any back contact battery cell portion and an adjacent back contact battery cell body, are all preset distances of 2d. The back contact battery cell portion is a half-cell structure after the back contact battery cell body is divided into two. Wherein, M is a positive integer, N is a positive integer greater than 1, and d and w are both positive numbers.

[0009] The PCB backplane includes an insulating substrate layer, a copper cladding layer, and a solder mask layer arranged sequentially from bottom to top. The copper cladding layer has conductive lines that are electrically connected to the back contact cell array. The PCB backplane is in contact with the back contact cell body and the back light surface of the back contact cell portion in the back contact cell array through the solder mask layer.

[0010] In some embodiments, the total number of positive electrode main grid lines and negative electrode main grid lines in any one of the back contact cell segments is half the total number of positive electrode main grid lines and negative electrode main grid lines in the main body of the back contact cell, and the total number of positive electrode main grid lines and negative electrode main grid lines in any one of the main bodies of the back contact cell is an even number.

[0011] In some embodiments, in the back contact cell array, the positive electrode main grid line and the negative electrode main grid line in any first cell row unit are all laterally misaligned with the positive electrode main grid line and the negative electrode main grid line in the adjacent second cell row unit, and the lateral misalignment interval is d; the N-1 back contact cell bodies and the two back contact cell portions in any second cell row unit are all rotated 180° relative to the back contact cell bodies in the first cell row unit, so that the polarities of any set of misaligned corresponding electrode main grid lines are opposite;

[0012] The conductive circuit includes M first conductive units and M second conductive units arranged alternately along the longitudinal direction. Each first conductive unit includes N main conductive groups arranged laterally, and the lateral spacing between any two adjacent main conductive groups is a preset distance of 2d. Each main conductive group includes positive copper foil connecting lines and negative copper foil connecting lines arranged alternately in the lateral direction, and the lateral spacing between any positive copper foil connecting line and an adjacent negative copper foil connecting line is a preset distance w. Each second conductive unit includes N-1 main conductive groups arranged continuously in the lateral direction, and branch conductive groups respectively arranged at both ends of the N-1 main conductive groups. The lateral spacing between any two adjacent main conductive groups and the lateral spacing between any branch conductive group and an adjacent main conductive group are both preset distances of 2d. The branch conductive group is a half-group structure after the main conductive group is divided into two.

[0013] The positive and negative copper foil connecting lines in the first conductive unit are matched one-to-one with the positive and negative main grid lines in the first battery row unit; the positive and negative copper foil connecting lines in the second conductive unit are matched one-to-one with the positive and negative main grid lines in the second battery row unit; and the lateral misalignment interval between any negative copper foil connecting line in the first conductive unit and the corresponding positive copper foil connecting line in the adjacent second conductive unit is d.

[0014] In some embodiments, in the back contact cell array, the positive electrode main grid line and the negative electrode main grid line in any first cell row unit are all laterally staggered with the positive electrode main grid line and the negative electrode main grid line in the adjacent second cell row unit, and the lateral staggering interval is d; the N-1 back contact cell bodies and the two back contact cell portions in any second cell row unit are arranged in the same direction as the back contact cell bodies in the first cell row unit, so that the polarity between any set of staggered corresponding two electrode main grid lines is the same;

[0015] The conductive circuit includes M first conductive units and M second conductive units arranged alternately along the longitudinal direction. Each first conductive unit includes N main conductive groups arranged laterally, and the lateral spacing between any two adjacent main conductive groups is a preset distance of 2d. Each main conductive group includes positive copper foil connecting lines and negative copper foil connecting lines arranged alternately in the lateral direction, and the lateral spacing between any positive copper foil connecting line and an adjacent negative copper foil connecting line is a preset distance w. Each second conductive unit includes N-1 main conductive groups arranged continuously in the lateral direction, and branch conductive groups respectively arranged at both ends of the N-1 main conductive groups. The lateral spacing between any two adjacent main conductive groups and the lateral spacing between any branch conductive group and an adjacent main conductive group are both preset distances of 2d. The branch conductive group is a half-group structure after the main conductive group is divided into two.

[0016] The positive and negative copper foil connecting lines in the first conductive unit are matched one-to-one with the positive and negative main grid lines in the first battery row unit; the positive and negative copper foil connecting lines in the second conductive unit are matched one-to-one with the positive and negative main grid lines in the second battery row unit; and the lateral misalignment interval between any negative copper foil connecting line in the first conductive unit and the corresponding laterally misaligned negative copper foil connecting line in the adjacent second conductive unit is d, and the lateral misalignment interval between any positive copper foil connecting line and the corresponding laterally misaligned positive copper foil connecting line in the adjacent second conductive unit is d.

[0017] In some embodiments, the conductive circuit further includes a positive copper foil busbar disposed at the upper end of the first conductive unit and a negative copper foil busbar disposed at the lower end of the second conductive unit.

[0018] Between any adjacent first conductive unit and second conductive unit, the corresponding negative copper foil connecting lines and positive copper foil connecting lines are connected through electrode interconnect lines to achieve vertical series connection of all first conductive units and second conductive units; wherein, all the positive copper foil connecting lines of the uppermost first conductive unit are connected to the positive copper foil bus bar, and the positive copper foil bus bar is connected to a positive copper foil lead-out line; all the negative copper foil connecting lines of the lowermost second conductive unit are connected to the negative copper foil bus bar, and the negative copper foil bus bar is connected to a negative copper foil lead-out line;

[0019] Both the positive electrode copper foil busbar and the negative electrode copper foil busbar are provided with busbar lead-out contacts at their ends.

[0020] In some embodiments, in any first conductive unit, a battery cell positioning mark is provided around the perimeter and / or at the four corners of any main conductive group; in any second conductive unit, a battery cell positioning mark is provided around the perimeter and / or at the four corners of any main conductive group and any branch conductive group.

[0021] In some embodiments, the conductive line further includes a copper foil lead wire, which is disposed in the row spacing between adjacent first conductive units and second conductive units and passes through and connects with the electrode interconnect; the end of the copper foil lead wire is provided with a lead wire lead-out contact.

[0022] In some embodiments, a positive electrode solder joint is provided on any one of the positive electrode main grid lines, and a negative electrode solder joint is provided on any one of the negative electrode main grid lines; the solder resist layer includes a second cell positioning mark, solder resist layer lead-out contacts, and a plurality of exposed copper points, the exposed copper points matching the layout of the positive electrode solder joints and the negative electrode solder joints in the back contact cell array; the second cell positioning mark matches the layout of the first cell positioning mark; the solder resist layer lead-out contacts include a second busbar lead-out contact and a second lead wire lead-out contact, the second busbar lead-out contact matching the layout of the first busbar lead-out contact, and the second lead wire lead-out contact matching the layout of the first lead wire lead-out contact;

[0023] One end of the positive copper foil lead wire is connected to the positive copper foil busbar, and the other end is exposed on the PCB backplane surface through the solder mask layer, forming a positive lead-out terminal; one end of the negative copper foil lead wire is connected to the negative copper foil busbar, and the other end is exposed on the PCB backplane surface through the solder mask layer, forming a negative lead-out terminal.

[0024] On the other hand, the present invention proposes a method for preparing a back-contact solar cell module as described in any one of the above claims, comprising:

[0025] The back contact cell body is divided into two parts in the horizontal direction, and the resulting half cell structure is used as the back contact cell part.

[0026] A plurality of the back contact cell bodies and a plurality of the back contact cells are arranged longitudinally and transversely on the solder resist layer to form the back contact cell array on the surface of the solder resist layer.

[0027] The PCB backplane is soldered to the back contact cell array using SMT technology to assemble the back contact solar cell module.

[0028] In another aspect, the present invention provides a photovoltaic power generation system, including the aforementioned back-contact solar cell module.

[0029] The present invention achieves the following technical effects compared to the prior art:

[0030] The back-contact solar cell module proposed in this invention uses conventional back-contact cells, and divides the cells into two halves as back-contact cell portions. This allows for the construction of a staggered array of cells using the main back-contact cell and the back-contact cell portions. When a half-cell is shaded, its internal loss is reduced to 1 / 4 of the original loss of the entire cell, effectively reducing hot spot effects and preventing excessive temperature rise in the module. At the same time, by removing the rectangular transition area, the silicon wafer cost of the module is reduced.

[0031] Using PCB as the backplane of back-contact solar cell modules, the conductive lines manufactured by PCB printed circuit board technology can compensate for the lateral misalignment of the dissimilar electrodes in the misaligned cell array, so that the spacing between the back-contact cell bodies and between the back-contact cell bodies and the back-contact cell sections in the misaligned cell array is uniformly 2d, which can reduce the process complexity of wiring and improve the consistency of the electrical performance of the cell module.

[0032] Therefore, the back-contact solar cell module of the present invention solves the problems of increased silicon wafer cost caused by the use of rectangular transition areas in the prior art, and high process complexity and poor electrical performance consistency caused by array layout with different spacing.

[0033] To address the shortcomings of existing technologies where laser cutting is required to correct short-circuit welding wires for carrier film welding, which is not only complex but also requires high alignment accuracy, this invention employs SMT (Surface Mount Technology) assembly between the PCB backplane and the back contact cell array. This eliminates the laser correction process required in existing technologies, simplifies the welding process of back contact solar cell modules, and improves the production efficiency of back contact solar cell modules.

[0034] For PCB conductive lines hidden in the PCB copper layer, EL testing of components can be achieved during production by setting lead-out contacts. The lead-out contacts can also be connected to diodes to form bypass diodes, meeting the anti-shading performance requirements of different battery cells.

[0035] The photovoltaic power generation system proposed in this invention includes the aforementioned back-contact solar cell module and possesses all the characteristics of the aforementioned back-contact solar cell module, which will not be repeated here. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of the back contact battery cell body and the back contact battery cell portion disclosed in an embodiment of the present invention.

[0038] Figure 2 This is a schematic diagram of the back contact battery cell array disclosed in Embodiment 1 of the present invention.

[0039] Figure 3 This is a schematic diagram of the conductive lines in the PCB backplane disclosed in Embodiment 1 of the present invention.

[0040] Figure 4 This is a schematic diagram of the solder mask layer in the PCB backplane disclosed in Embodiment 1 of the present invention.

[0041] Figure 5 This is a schematic diagram of the circuit connection structure of the back-contact solar cell module disclosed in Embodiment 1 of the present invention.

[0042] Figure 6 This is a schematic diagram of the conductive lines in the PCB backplane disclosed in Embodiment 2 of the present invention.

[0043] Figure 7 This is a schematic diagram of the solder mask layer in the PCB backplane disclosed in Embodiment 2 of the present invention.

[0044] Figure 8 This is a schematic diagram of the back contact battery cell array disclosed in Embodiment 3 of the present invention.

[0045] Figure 9 This is a schematic diagram of the conductive lines in the PCB backplane disclosed in Embodiment 3 of the present invention.

[0046] Figure 10 This is a schematic diagram of the solder mask layer in the PCB backplane disclosed in Embodiment 3 of the present invention.

[0047] Figure 11 This is a schematic diagram of the circuit connection structure of the back-contact solar cell module disclosed in Embodiment 3 of the present invention.

[0048] Figure 12 This is a schematic diagram of the conductive lines in the PCB backplane disclosed in Embodiment 4 of the present invention.

[0049] Figure 13 This is a schematic diagram of the solder mask layer in the PCB backplane disclosed in Embodiment 4 of the present invention.

[0050] In the diagram: 100 - Back contact cell array; 1 - First cell row unit; 2 - Second cell row unit; 3 - Back contact cell body; 31 - Positive electrode main grid line; 311 - Positive electrode solder joint; 32 - Negative electrode main grid line; 321 - Negative electrode solder joint; 4 - Back contact cell section; 5 - Exposed copper point; 6 - Copper cladding layer; 7 - Solder resist layer; 8 - Positive electrode copper foil connection line; 9 - Negative electrode copper foil connection line; 10 - First conductive unit; 11 - Second conductive unit; 12 - Main conductive group ; 13-Sub-conductive group; 14-Positive electrode copper foil busbar; 15-Negative electrode copper foil busbar; 16-Positive electrode copper foil lead-out wire; 17-Negative electrode copper foil lead-out wire; 18-Electrode interconnection wire; 19-Busbar lead-out contact one; 20-Cell positioning mark one; 21-Copper foil lead-out wire; 22-Lead-out wire lead-out contact one; 23-Positive electrode lead-out terminal; 24-Negative electrode lead-out terminal; 25-Cell positioning mark two; 26-Busbar lead-out contact two; 27-Lead-out wire lead-out contact two. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] One of the objectives of this invention is to provide a back-contact solar cell module that uses PCB conductive lines to compensate for the lateral misalignment of the dissimilar electrodes in the misaligned array of back-contact solar cells. This ensures uniform spacing between any two adjacent solar cell bodies and between any adjacent solar cell bodies and solar cell sections in the misaligned array of back-contact solar cells, thereby reducing process complexity and ensuring the consistency of the electrical performance of the photovoltaic module, thus solving the problems existing in the prior art.

[0053] Another object of the present invention is to provide a method for preparing the above-mentioned back-contact solar cell module.

[0054] Another object of the present invention is to provide a photovoltaic power generation system comprising the above-described back-contact solar cell module.

[0055] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0056] Example 1

[0057] This embodiment provides a back-contact solar cell module, including a back-contact cell array 100 and a PCB backplane. Wherein:

[0058] The back-contact solar cell array 100 includes M first battery row units 1 and M second battery row units 2 arranged alternately along the longitudinal direction. That is, the first battery row units 1 and second battery row units 2 are arranged alternately along the longitudinal direction. Except for the first battery row unit 1 and second battery row unit 2 located at the very top or bottom, the upper and lower adjacent units of any other first battery row unit 1 are all second battery row units 2, and vice versa. In practical applications, the first row (i.e., the topmost unit) of each back-contact solar cell array 100 can be either a first battery row unit 1 or a second battery row unit 2. It should be noted that M is a positive integer, preferably with a value range of M ≥ 2.

[0059] Each first battery row unit 1 includes N back-contact battery cell bodies 3 arranged equidistantly in the horizontal direction, where N is a positive integer greater than 1. The horizontal spacing between any two adjacent back-contact battery cell bodies 3 is a preset distance 2d (d is a positive number). The structural dimensions of each back-contact battery cell body 3 are identical. Each back-contact battery cell body 3 has multiple positive electrode main grid lines 31 and multiple negative electrode main grid lines 32 on its back surface, and the positive electrode main grid lines 31 and negative electrode main grid lines 32 are arranged alternately along the horizontal extension direction of the back-contact battery cell body 3. The horizontal spacing between any positive electrode main grid line 31 and the adjacent negative electrode main grid line 32 along the back-contact battery cell body 3 is a preset distance w (w is a positive number).

[0060] like Figure 1 As shown, each positive electrode main grid line 31 is provided with a positive electrode solder joint 311, and each negative electrode main grid line 32 is provided with a negative electrode solder joint 321. Among them, the positive electrode solder joint 311 is represented by "○", and the negative electrode solder joint 321 is represented by "□".

[0061] Each second battery row unit 2 includes N-1 back contact battery cell bodies 3 arranged continuously and at equal intervals in the horizontal direction, and back contact battery cell portions 4 respectively arranged at both ends of the N-1 back contact battery cell bodies 3. The horizontal distance between any two adjacent back contact battery cell bodies 3 is a preset distance 2d, and the horizontal distance between any back contact battery cell portion 4 and the adjacent back contact battery cell body 3 is a preset distance 2d. The back contact cell body 3 in the second battery row unit 2 is exactly the same as the back contact cell body 3 in the first battery row unit 1. The back contact cell segment 4 is the structure after the back contact cell body 3 is divided into two parts. Specifically, the lateral length of the back contact cell segment 4 is half the lateral length of the back contact cell body 3. At the same time, the positive electrode main grid line 31 and the negative electrode main grid line 32 are alternately arranged laterally on the back surface of the back contact cell segment 4. The total number of positive electrode main grid lines 31 and negative electrode main grid lines 32 in the back contact cell segment 4 is half the total number of positive electrode main grid lines 31 and negative electrode main grid lines 32 in the back contact cell body 3. In some specific embodiments, preferably, in any back-contact cell body 3, the total number of positive electrode main grid lines 31 and negative electrode main grid lines 32 is even. Correspondingly, in any back-contact cell segment 4, the total number of positive electrode main grid lines 31 and negative electrode main grid lines 32 is also even, and is half of the total number of positive electrode main grid lines 31 and negative electrode main grid lines 32 in the back-contact cell body 3. Since the back-contact cell segment 4 is half of the back-contact cell body 3, the lateral spacing between any positive electrode main grid line 31 and the adjacent negative electrode main grid line 32 in any back-contact cell segment 4 is also a preset distance w.

[0062] The total number of positive electrode main grid lines 31 and negative electrode main grid lines 32 is the same for any first battery row unit 1 and any second battery row unit 2, and the total number is preferably even. After the first battery row units 1 and the second battery row units 2 are arranged alternately along the longitudinal direction, any back contact battery cell body 3 in the second battery row unit 2 is located between two adjacent back contact battery cell bodies 3 in the adjacent first battery row unit 1, and the center line parallel to the longitudinal direction of the back contact battery cell body 3 in the second battery row unit 2 coincides with the center line of the lateral interval between two adjacent back contact battery cell bodies 3 in the first battery row unit 1.

[0063] In any first battery row unit 1 and any second battery row unit 2, the positive electrode main grid line 31 and the negative electrode main grid line 32 of any back-contacting battery cell body 3 are both equally divided into two halves along the horizontal direction, that is, equally divided into two groups of half regions along the horizontal direction. In the first battery row unit 1:

[0064] ① In the back contact cell body 3 located at the end: the positive electrode main grid line 31 and the negative electrode main grid line 32 of one half of the region correspond one-to-one with all the positive electrode main grid lines 31 and the negative electrode main grid lines 32 in the back contact cell portion 4 of the adjacent second cell row unit 2, and are offset laterally; the positive electrode main grid lines 31 and the negative electrode main grid lines 32 of the other half of the region correspond one-to-one with the positive electrode main grid lines 31 and the negative electrode main grid lines 32 of the back contact cell body 3 of the adjacent second cell row unit 2 that have an offset relationship, and are offset laterally.

[0065] ②Apart from the two ends, any other back contact cell body 3 has a misalignment relationship with two adjacent back contact cell bodies 3 in the adjacent second battery row unit 2. Therefore, the positive electrode main grid line 31 and negative electrode main grid line 32 of the two halves of the back contact cell body 3 located in the middle position (i.e., any position between the two ends) in the first battery row unit 1 correspond one-to-one with the positive electrode main grid line 31 and negative electrode main grid line 32 of the two halves of the two back contact cell bodies 3 in the adjacent second battery row unit 2, and are misaligned in the lateral direction. Correspondingly, any one back-contact cell body 3 in the second battery row unit 2 is simultaneously misaligned with two adjacent back-contact cell bodies 3 in the adjacent first battery row unit 1. Therefore, the positive electrode main grid line 31 and negative electrode main grid line 32 of the two halves of any one back-contact cell body 3 in the second battery row unit 2 correspond one-to-one with the positive electrode main grid line 31 and negative electrode main grid line 32 of the two halves of the two back-contact cell bodies 3 in the adjacent first battery row unit 1, respectively, and are misaligned in the lateral direction.

[0066] It should be noted that the aforementioned "end" refers to the horizontal (left and right) end, not the top and bottom end.

[0067] refer to Figure 2 In any first battery row unit 1 and any second battery row unit 2, the positive electrode main grid line 31 and the negative electrode main grid line 32 of any two halves of the back-contacting battery cell body 3 are misaligned with the corresponding positive electrode main grid line 31 and the negative electrode main grid line 32 in opposite directions. In any corresponding upper and lower halves of the positive electrode main grid line 31 and the negative electrode main grid line 32, the misalignment direction of all electrodes is consistent.

[0068] Based on the electrode misalignment arrangement in the first battery row unit 1 and the second battery row unit 2, it is preferable that in the back contact cell array 100, all the first battery row units 1 are arranged aligned at both ends along the longitudinal direction, and correspondingly, all the second battery row units 2 are arranged aligned at both ends along the longitudinal direction. Simultaneously, the two back contact cell portions 4 located at both ends of any second battery row unit 2 are mirror-symmetrical about the centerline of the entire array. Based on the above structure, the lateral misalignment interval between any positive electrode main grid line 31 or negative electrode main grid line 32 in any first battery row unit 1 and the corresponding misaligned positive electrode main grid line 31 or negative electrode main grid line 32 in the adjacent second battery row unit 2 is half of a preset distance 2d, i.e., the lateral misalignment interval is d. Similarly, the lateral misalignment interval between any positive electrode main grid line 31 or negative electrode main grid line 32 in any second battery row unit 2 and the corresponding positive electrode main grid line 31 or negative electrode main grid line 32 in the adjacent first battery row unit 1 is also half of the preset distance 2d, that is, the lateral misalignment interval is d.

[0069] In some specific embodiments, it is preferable that the row spacing between any adjacent first battery row unit 1 and second battery row unit 2 is equal.

[0070] It should be noted that all instances of "horizontal" mentioned above and thereafter refer to the same direction. See [link to relevant documentation]. Figure 2 Each row is shown. Correspondingly, all instances of "vertical" above and thereafter refer to the same direction; "vertical" is perpendicular to "horizontal," see [link to documentation]. Figure 2 The arrangement direction of each row is shown.

[0071] The PCB backplane, serving as the backplane for the back-contact solar cell module, comprises a three-layer structure arranged from bottom to top: an insulating substrate layer, a copper cladding layer 6, and a solder resist layer 7. The solder resist layer 7 is the contact surface that contacts the backlighting surface of the back-contact cell body 3 and the back-contact cell portion 4. The insulating substrate layer is made of materials including, but not limited to, fiberglass FR4 board and PET. The copper cladding layer 6 is formed by removing excess copper through photolithography and etching processes to create conductive lines that match the positive electrode main grid lines 31 and negative electrode main grid lines 32 on the backlighting surface of the back-contact cell. The arrangement of these conductive lines is related to the lateral arrangement of the positive electrode main grid lines 31 and negative electrode main grid lines 32 in the first cell row unit 1 and the second cell row unit 2 of the aforementioned back-contact cell array 100.

[0072] Taking the N-1 back-contact battery cell bodies 3 in the second battery row unit 2 of the back-contact battery cell array 100 and the back-contact battery cell portions 4 respectively arranged at both ends of the N-1 back-contact battery cell bodies 3 as an example, all are rotated 180° relative to the back-contact battery cell bodies 3 in the first battery row unit 1. That is, the staggered arrangement direction of the positive electrode main grid line 31 and the negative electrode main grid line 32 in the first battery row unit 1 is exactly opposite to the staggered arrangement direction of the positive electrode main grid line 31 and the negative electrode main grid line 32 in the adjacent second battery row unit 2. At this time, in the first battery row unit 1 and the adjacent second battery row unit 2, the two electrodes that are in the aforementioned staggered correspondence relationship are one positive and one negative. For example, the negative electrode main grid line 32 of the first battery row unit 1 and the positive electrode main grid line 31 of the adjacent second battery row unit 2 are staggered, and the lateral staggered interval is d. Based on this, the conductive line includes M first conductive units 10 and M second conductive units 11 arranged alternately along the longitudinal direction, where M is a positive integer. The first and second conductive units include several copper foil connecting lines, including positive copper foil connecting lines 8 and negative copper foil connecting lines 9. The first conductive unit 10 includes N main conductive groups 12 (N is a positive integer greater than 1) arranged in the horizontal direction. The second conductive unit 11 includes N-1 main conductive groups 12 arranged in the horizontal direction and branch conductive groups 13 respectively arranged at both ends of the N-1 main conductive groups 12. Positive copper foil connecting lines 8 and negative copper foil connecting lines 9 are arranged in parallel and intersecting directions in the main conductive groups 12 and branch conductive groups 13. The horizontal spacing between the positive copper foil connecting lines 8 and negative copper foil connecting lines 9 in the main conductive groups 12 and branch conductive groups 13 is also w.

[0073] The positive electrode copper foil connecting line 8 and the negative electrode copper foil connecting line 9 in the first conductive unit 10 are matched one-to-one with the positive electrode main grid line 31 and the negative electrode main grid line 32 in the first battery row unit 1. That is, the positive electrode copper foil connecting line 8 is connected to the positive electrode main grid line 31 in the first battery row unit 1, and the negative electrode copper foil connecting line 9 is connected to the negative electrode main grid line 32 in the first battery row unit 1. Correspondingly, the positive electrode copper foil connecting line 8 and the negative electrode copper foil connecting line 9 in the second conductive unit 11 are matched one-to-one with the positive electrode main grid line 31 and the negative electrode main grid line 32 in the second battery row unit 2. That is, the positive electrode copper foil connecting line 8 is connected to the positive electrode main grid line 31 in the second battery row unit 2, and the negative electrode copper foil connecting line 9 is connected to the negative electrode main grid line 32 in the second battery row unit 2. The horizontal spacing between the negative copper foil connecting line 9 of the first conductive unit 10 and the adjacent positive copper foil connecting line 8 of the second conductive unit 11 is also 0.5 times the preset distance 2d, i.e., d. Correspondingly, the horizontal spacing between the positive copper foil connecting line 8 of the first conductive unit 10 and the adjacent negative copper foil connecting line 9 of the second conductive unit 11 is also d. In the first conductive unit 10 and the second conductive unit 11, the horizontal distance between any two adjacent main conductive groups 12 is the preset distance 2d; in the second conductive unit 11, the horizontal distance between any branch conductive group 13 and the adjacent main conductive group 12 is the preset distance 2d.

[0074] In some specific implementations, it is necessary to satisfy the preset distance 2d ≥ creepage distance between the electrode grid lines of the battery cell; w can be 9.75mm, which can be flexibly adjusted according to the actual application.

[0075] In some specific embodiments, the conductive circuit further includes a positive copper foil busbar 14 disposed at the uppermost first conductive unit 10 and a negative copper foil busbar 15 disposed at the lowermost second conductive unit 11. Specifically, the positive copper foil connecting line 8 of the uppermost first conductive unit 10 is connected to the positive copper foil busbar 14; the negative copper foil connecting line 9 of the first conductive unit 10 is connected to the adjacent positive copper foil connecting line 8 of the second conductive unit 11 via an electrode interconnect line 18; the negative copper foil connecting line 9 of the second conductive unit 11 is connected to the adjacent positive copper foil connecting line 8 of the next first conductive unit 10 via an electrode interconnect line 18, and this connection is repeated to achieve a longitudinal series connection between the first conductive unit 10 and the second conductive unit 11; the negative copper foil connecting line 9 of the lowermost second conductive unit 11 is connected to the negative copper foil busbar 15.

[0076] In some specific embodiments, a positive copper foil lead-out line 16 is also included. One end of the positive copper foil lead-out line 16 is connected to the positive copper foil busbar 14, and the other end is exposed on the PCB backplane surface through the solder mask layer 7, forming a positive lead-out terminal 23. Correspondingly, a negative copper foil lead-out line 17 is also included. One end of the negative copper foil lead-out line 17 is connected to the negative copper foil busbar 15, and the other end is exposed on the PCB backplane surface through the solder mask layer 7, forming a negative lead-out terminal 24.

[0077] In some specific embodiments, one end of the positive electrode copper foil busbar 14 and the negative electrode copper foil busbar 15 is provided with a busbar lead-out contact 19.

[0078] In some specific embodiments, the positive electrode copper foil connecting line 8, the electrode interconnect line 18, and the negative electrode copper foil connecting line 9 are preferably integral structures continuously etched on the same copper cladding layer 6.

[0079] In some specific embodiments, in any first conductive unit 10 of the PCB backplane, a battery cell positioning mark 20 is provided around and / or at the four corners of any main conductive group 12; correspondingly, in any second conductive unit 11, a battery cell positioning mark 20 is provided around and / or at the four corners of any main conductive group 12 and any branch conductive group 13, so as to facilitate the positioning and placement of the back contact battery cell main body 3 and the back contact battery cell branch 4.

[0080] In order to reduce the interference or obstruction of each electrode by the battery cell positioning mark 20, it is preferable to set the battery cell positioning mark 20 only at the four corners of any main conductive group 12 and the four corners of any sub-conductive group 13. The battery cell positioning mark 20 adopts a right-angle mark, which corresponds to the outline of the battery cell, so as to facilitate the positioning and placement of the battery cell.

[0081] In some specific embodiments, the conductive circuit may also include copper foil lead-in lines 21. These copper foil lead-in lines 21 are positioned between the first conductive unit 10 and the second conductive unit 11, parallel to the positive copper foil busbar 14 and the negative copper foil busbar 15, and pass through the electrode interconnect line 18 connecting the first conductive unit 10 and the second conductive unit 11. One end of the copper foil lead-in line 21 is provided with a lead-in contact 22. The number of copper foil lead-in lines 21 can be flexibly set to meet the requirements of different components for EL testing and shielding performance.

[0082] In some specific embodiments, the solder mask layer 7 includes a positive electrode lead-out terminal 23, a negative electrode lead-out terminal 24, a second cell positioning mark 25, solder mask layer lead-out contacts, and several exposed copper points 5. The layout of the exposed copper points 5 corresponds to the positive electrode solder point 311 and the negative electrode solder point 321 on the back surface of the cell in the back contact cell array 100. The second cell positioning mark 25 also adopts right-angle marks distributed at the four corners, and the layout of the second cell positioning mark 25 matches the layout of the first cell positioning mark 20 in the copper cladding layer 6, and matches the layout of the back contact cell body 3 and the back contact cell portion 4 in the back contact cell array 100. The aforementioned solder mask layer leads include busbar leads and lead wire leads. To distinguish them from the leads in the copper clad layer 6, the busbar leads and lead wire leads in the solder mask layer 7 are defined as busbar lead contact 26 and lead wire lead contact 27, respectively. The layout of busbar lead contact 26 and lead wire lead contact 27 matches the layout of busbar lead contact 19 and lead wire lead contact 22 in the copper clad layer 6, so that the solder mask layer 7 can expose busbar lead contact 19 and lead wire lead contact 22.

[0083] In some specific implementations, the back-light surfaces of both the back-contact cell body 3 and the back-contact cell portion 4 are surface-mount soldered to the PCB backplane (i.e., SMT soldering technology). Specifically: solder is printed on the PCB solder mask layer to match the layout of the exposed copper points 5, forming solder pads; according to the cell positioning mark 25 on the PCB solder mask layer, the back-contact cell body 3 and the back-contact cell portion 4 are picked up one by one and transferred onto the PCB, so that the back-light surfaces of the back-contact cell body 3 and the back-contact cell portion 4 are in contact with and positioned at corresponding positions on the solder mask layer 7 of the PCB board, forming the back-contact cell array 100; the PCB backplane with the back-contact cell array 100 is transported to a reflow oven, where the solid solder paste is liquefied at high temperature to complete the soldering, followed by cooling and solidification. Finally, the encapsulation layer and the panel are sequentially placed on the entire light-receiving surface of the back-contact cell array 100, and the back-contact solar cell module is finally obtained through a lamination process.

[0084] like Figures 1-5 As shown, the following example, with M=2 and N=2, provides a specific illustration of the structural arrangement and circuit connection of the back-contact solar cell module described above in this embodiment.

[0085] like Figure 1 As shown, on the back-light surface of the back-contact solar cell body 3, six positive electrode main grid lines 31 and six negative electrode main grid lines 32 are arranged alternately; on the back-contact solar cell section 4, three positive electrode main grid lines 31 and three negative electrode main grid lines 32 are arranged alternately. In both the back-contact solar cell body 3 and the back-contact solar cell section 4, the lateral spacing between any positive electrode main grid line and the adjacent negative electrode main grid line is a preset distance w.

[0086] like Figure 2 As shown, the back-contact solar cell module includes two first cell row units 1 and two second cell row units 2 arranged alternately along the longitudinal direction. The first cell row unit 1 includes two back-contact cell bodies 3 arranged laterally, with a predetermined distance of 2d between the two back-contact cell bodies 3. The second cell row unit 2 includes one back-contact cell body 3 arranged laterally and rotated 180°, and two back-contact cell portions 4 arranged at both ends of the back-contact cell body 3 and rotated 180°, with the distance between any back-contact cell portion 4 and the back-contact cell body 3 along the transverse direction being the predetermined distance of 2d. The transverse distance between the negative electrode main grid line 32 of the first cell row unit 1 and the corresponding staggered positive electrode main grid line 31 in the adjacent second cell row unit 2 is d; similarly, the transverse distance between the positive electrode main grid line 32 of the first cell row unit 1 and the corresponding staggered negative electrode main grid line 32 in the adjacent second cell row unit 2 is d.

[0087] like Figure 3 As shown, the conductive circuit includes two first conductive units 10 and two second conductive units 11 arranged alternately along the longitudinal direction. Each first and second conductive unit includes several copper foil connecting lines, including positive copper foil connecting lines 8 and negative copper foil connecting lines 9. The first conductive unit 10 includes two main conductive groups 12 arranged laterally, with a predetermined distance of 2d between the two main conductive groups 12. The second conductive unit 11 includes one main conductive group 12 arranged laterally and two branch conductive groups 13 respectively arranged at both ends of the main conductive group 12. The distance between any branch conductive group 13 and the main conductive group 12 along the transverse direction is a predetermined distance of 2d. Positive copper foil connecting lines 8 and negative copper foil connecting lines 9 are arranged in parallel and interleaved patterns within the main conductive group 12 and the branch conductive group 13, with a transverse interval of w between any adjacent positive copper foil connecting lines 8 and negative copper foil connecting lines 9 within the main conductive group 12 and the branch conductive group 13. The horizontal distance between the negative copper foil connecting line 9 of the first conductive unit 10 and the corresponding positive copper foil connecting line 8 of the adjacent second conductive unit 11 is d. Similarly, the horizontal distance between the positive copper foil connecting line 8 of the first conductive unit 10 and the corresponding negative copper foil connecting line 9 of the adjacent second conductive unit 11 is d.

[0088] The positive electrode copper foil connecting line 8 and the negative electrode copper foil connecting line 9 of the first conductive unit 10 are matched one-to-one with the positive electrode main grid line 31 and the negative electrode main grid line 32 on the back light surface of the back contact battery cell body 3 in the first battery row unit 1. The positive electrode copper foil connecting line 8 and the negative electrode copper foil connecting line 9 of the second conductive unit 11 are matched one-to-one with the positive electrode main grid line 31 and the negative electrode main grid line 32 on the back light surface of the back contact battery cell body 3 and the back contact battery cell division 4 in the second battery row unit 2.

[0089] Each of the positive copper foil busbar 14 and the negative copper foil busbar 15 is provided with a busbar lead-out contact 19 for EL testing. The lead-out contact can also be connected to a diode to form a bypass diode circuit, thereby improving the component's anti-shading performance.

[0090] The circuit connection method of the back-contact solar cell module is as follows: the positive electrode main grid lines 31 of the two back-contact cell bodies 3 of the first cell row unit 1 are connected to the positive electrode copper foil busbar 14 through the exposed copper point 5 and the positive electrode copper foil connecting line 8, and converge to the positive electrode lead-out terminal 23. The negative electrode main grid lines 32 of the two back-contact cell bodies 3 of the first cell row unit 1 are connected to the positive electrode main grid lines 31 of the back-contact cell bodies and the two back-contact cell segments 4 in the second cell row unit 2 with a staggered corresponding relationship through the exposed copper point 5, the negative electrode copper foil connecting line 9, the electrode interconnect line 18, and the positive electrode copper foil connecting line 8. The negative electrode main grid lines 32 of the back-contact cell bodies 3 and the two back-contact cell segments 4 of the second cell row unit 2 are connected through the exposed copper point 5, the negative electrode copper foil connecting line 9, and the electrode interconnect line 18. Line 18 and positive electrode copper foil connecting line 8 are connected to the positive electrode main grid lines 31 of the two back contact battery cell bodies 3 in the second first battery row unit 1 with a staggered correspondence. The negative electrode main grid lines 32 of the two back contact battery cell bodies 3 in the second first battery row unit 1 are connected to the positive electrode main grid lines 31 of the back contact battery cell bodies 3 and the two back contact battery cell segments 4 in the second second battery row unit 2 with a staggered correspondence through exposed copper point 5, negative electrode copper foil connecting line 9, electrode interconnect line 18, and positive electrode copper foil connecting line 8. The negative electrode main grid lines 32 of the back contact battery cell bodies 3 and the two back contact battery cell segments 4 in the second second battery row unit 2 are connected to the negative electrode copper foil busbar 15 through exposed copper point 5 and negative electrode copper foil connecting line 9, and converge to the negative electrode lead-out terminal 24.

[0091] Example 2

[0092] like Figures 6-7 As shown, this embodiment is similar to the example in Embodiment 1, except that:

[0093] like Figure 6As shown, in this embodiment, the conductive lines of the copper-clad layer 6 of the PCB backplane are provided with three copper foil lead-in lines 21. Each copper foil lead-in line 21 is located between the first conductive unit 10 and the second conductive unit 11, parallel to the positive copper foil busbar 14 and the negative copper foil busbar 15, and passes through the electrode interconnect line 18 connecting the first conductive unit 10 and the second conductive unit 11. One end of the copper foil lead-in line 21 is provided with a lead-in line lead-out contact 22. Each lead-in line lead-out contact 22 is exposed through a lead-in line lead-out contact 27 in the solder mask layer 7, which can be used to test the EL of each area of ​​the component, or to connect diodes to build a bypass diode circuit to further enhance the anti-shielding performance of the component. For example, one end of the positive copper foil busbar 14 is provided with a busbar lead-out contact 26 exposed to the solder mask layer 7, and one end of the adjacent copper foil lead-out line 21 is provided with a lead-out contact 27 exposed to the solder mask layer 7. Then, by applying a reverse voltage between the busbar lead-out contact 26 and the lead-out contact 27, the first battery row cell 1 region can be tested. A diode can also be connected between the busbar lead-out contact 26 and the lead-out contact 27 to provide a parallel bypass diode for the first battery row cell 1 region.

[0094] Example 3

[0095] This embodiment provides a back-contact solar cell module, which differs from Embodiment 1 only in that:

[0096] In the back contact cell array 100, the N-1 back contact cell bodies 3 in the second cell row unit 2 and the back contact cell portions 4 respectively arranged at both ends of the N-1 back contact cell bodies 3 are arranged in the same transverse direction as the back contact cell bodies 3 in the first cell row unit 1. That is, the staggered arrangement direction of the positive electrode main grid line 31 and the negative electrode main grid line 32 in the first cell row unit 1 is consistent with the staggered arrangement direction of the positive electrode main grid line 31 and the negative electrode main grid line 32 in the adjacent second cell row unit 2. At this time, in the first cell row unit 1 and the adjacent second cell row unit 2, the two electrodes that are in the aforementioned staggered correspondence are both positive or both are negative. For example, the negative (positive) electrode main grid line of the first cell row unit 1 is staggered with the negative (positive) electrode main grid line of the adjacent second cell row unit 2, and the transverse staggered interval is d. Based on this, the conductive lines of the PCB backplane include M first conductive units 10 and M second conductive units 11 arranged alternately in the longitudinal direction, where M is a positive integer. The first and second conductive units include several copper foil connecting lines, including positive copper foil connecting lines 8 and negative copper foil connecting lines 9. The first conductive unit 10 includes N main conductive groups 12 (N is a positive integer greater than 1) arranged in the horizontal direction. The second conductive unit 11 includes N-1 main conductive groups 12 arranged in the horizontal direction and branch conductive groups 13 respectively arranged at both ends of the N-1 main conductive groups 12. Positive copper foil connecting lines 8 and negative copper foil connecting lines 9 are arranged in parallel and intersecting directions in the main conductive groups 12 and branch conductive groups 13. The horizontal spacing between the positive copper foil connecting lines 8 and negative copper foil connecting lines 9 in the main conductive groups 12 and branch conductive groups 13 is also w.

[0097] The positive electrode copper foil connecting line 8 and the negative electrode copper foil connecting line 9 in the first conductive unit 10 are matched one-to-one with the positive electrode main grid line 31 and the negative electrode main grid line 32 in the first battery row unit 1. That is, the positive electrode copper foil connecting line 8 is connected to the positive electrode main grid line 31 in the first battery row unit 1, and the negative electrode copper foil connecting line 9 is connected to the negative electrode main grid line 32 in the first battery row unit 1. Correspondingly, the positive electrode copper foil connecting line 8 and the negative electrode copper foil connecting line 9 in the second conductive unit 11 are matched one-to-one with the positive electrode main grid line 31 and the negative electrode main grid line 32 in the second battery row unit 2. That is, the positive electrode copper foil connecting line 8 is connected to the positive electrode main grid line 31 in the second battery row unit 2, and the negative electrode copper foil connecting line 9 is connected to the negative electrode main grid line 32 in the second battery row unit 2. The horizontal spacing between the negative copper foil connecting line 9 of the first conductive unit 10 and the adjacent negative copper foil connecting line 9 of the second conductive unit 11 is also 0.5 times the preset distance 2d, i.e., d. Correspondingly, the horizontal spacing between the positive copper foil connecting line 8 of the first conductive unit 10 and the adjacent positive copper foil connecting line 8 of the second conductive unit 11 is also d. In the first conductive unit 10 and the second conductive unit 11, the horizontal distance between any two adjacent main conductive groups 12 is the preset distance 2d; in the second conductive unit 11, the horizontal distance between any branch conductive group 13 and the adjacent main conductive group 12 is the preset distance 2d.

[0098] Unlike Embodiment 1, in this embodiment, when the first conductive unit 10 and the second conductive unit 11 are connected in the longitudinal series, the electrode interconnects 18 connecting the negative copper foil connecting line 9 of the first conductive unit 10 and the corresponding positive copper foil connecting line 8 of the second conductive unit 11, as well as the electrode interconnects 18 connecting the negative copper foil connecting line 9 of the second conductive unit 11 and the corresponding positive copper foil connecting line 8 adjacent to the next first conductive unit 10, all require electrode interconnects 18 with a longer lateral span. This is because the lateral spacing between the positive copper foil connecting line 8 and the negative copper foil connecting line 9 at both ends of any electrode interconnect 18 is larger than that in Embodiment 1.

[0099] like Figures 8-11 As shown, the following example, with M=2 and N=2, provides a specific illustration of the structural arrangement and circuit connection of the back-contact solar cell module described above in this embodiment.

[0100] This example is similar to the example in Example 1, and adopts the following... Figure 1 The back contact cell body 3 and back contact cell portion 4 are shown. The difference from Embodiment 1 is that:

[0101] like Figure 8As shown, the back-contact solar cell module includes two first cell row units 1 and two second cell row units 2 arranged alternately along the longitudinal direction. The first cell row unit 1 includes two back-contact cell bodies 3 arranged laterally, with a predetermined distance of 2d between the two back-contact cell bodies 3. The second cell row unit 2 includes one back-contact cell body 3 arranged laterally and two back-contact cell portions 4 arranged at both ends of the back-contact cell body 3, with a predetermined distance of 2d between any back-contact cell portion 4 and the back-contact cell body 3. The distance d along the transverse direction between the negative electrode main grid line 32 of the first cell row unit 1 and the corresponding offset negative electrode main grid line 32 in the adjacent second cell row unit 2 is also d. Similarly, the distance d along the transverse direction between the positive electrode main grid line 31 of the first cell row unit 1 and the corresponding offset positive electrode main grid line 31 in the adjacent second cell row unit 2 is also d.

[0102] like Figure 9 As shown, the conductive circuit includes two first conductive units 10 and two second conductive units 11 arranged alternately along the longitudinal direction. Each first and second conductive unit includes several copper foil connecting lines, including positive copper foil connecting lines 8 and negative copper foil connecting lines 9. The first conductive unit 10 includes two main conductive groups 12 arranged laterally, with a predetermined distance of 2d between the two main conductive groups 12. The second conductive unit 11 includes one main conductive group 12 arranged laterally and two branch conductive groups 13 respectively arranged at both ends of the main conductive group 12. The distance between any branch conductive group 13 and the main conductive group 12 along the transverse direction is a predetermined distance of 2d. Positive copper foil connecting lines 8 and negative copper foil connecting lines 9 are arranged in parallel and interleaved patterns within the main conductive group 12 and the branch conductive group 13, with a transverse interval of w between any adjacent positive copper foil connecting lines 8 and negative copper foil connecting lines 9 within the main conductive group 12 and the branch conductive group 13. The horizontal distance between the negative copper foil connecting line 9 of the first conductive unit 10 and the corresponding negative copper foil connecting line 9 of the adjacent second conductive unit 11 is d. Similarly, the horizontal distance between the positive copper foil connecting line 8 of the first conductive unit 10 and the corresponding positive copper foil connecting line 8 of the adjacent second conductive unit 11 is d.

[0103] The positive electrode copper foil connecting line 8 and the negative electrode copper foil connecting line 9 of the first conductive unit 10 are matched one-to-one with the positive electrode main grid line 31 and the negative electrode main grid line 32 on the back light surface of the back contact battery cell body 3 in the first battery row unit 1. The positive electrode copper foil connecting line 8 and the negative electrode copper foil connecting line 9 of the second conductive unit 11 are matched one-to-one with the positive electrode main grid line 31 and the negative electrode main grid line 32 on the back light surface of the back contact battery cell body 3 and the back contact battery cell division 4 in the second battery row unit 2.

[0104] Each of the positive copper foil busbar 14 and the negative copper foil busbar 15 is provided with a busbar lead-out contact 19 for EL testing. The lead-out contact can also be connected to a diode to form a bypass diode circuit, thereby improving the component's anti-shading performance.

[0105] The circuit connection method of the back-contact solar cell module is as follows: the positive electrode main grid lines 31 of the two back-contact cell bodies 3 of the first cell row unit 1 are connected to the positive electrode copper foil busbar 14 through the exposed copper point 5 and the positive electrode copper foil connecting line 8, and converge to the positive electrode lead-out terminal 23. The negative electrode main grid lines 32 of the two back-contact cell bodies 3 of the first cell row unit 1 are connected to the corresponding positive electrode main grid lines 31 of the back-contact cell bodies 3 and the two back-contact cell sub-sections 4 in the second cell row unit 2 through the exposed copper point 5, the negative electrode copper foil connecting line 9, the electrode interconnect line 18, and the positive electrode copper foil connecting line 8. The negative electrode main grid lines 32 of the back-contact cell bodies 3 and the two back-contact cell sub-sections 4 of the second cell row unit 2 are connected through the exposed copper point 5 and the negative electrode copper foil connecting line 9. Electrode interconnect line 18 and positive electrode copper foil connection line 8 are connected to the corresponding positive electrode main grid line 31 of the two back contact cell bodies 3 in the second first battery row unit 1. The negative electrode main grid line 32 of the two back contact cell bodies 3 in the second first battery row unit 1 is connected to the corresponding positive electrode main grid line 31 of the back contact cell body 3 and the two back contact cell segments 4 in the second second battery row unit 2 through exposed copper point 5, negative electrode copper foil connection line 9, electrode interconnect line 18, and positive electrode copper foil connection line 8. The negative electrode main grid line 32 of the back contact cell body 3 and the two back contact cell segments 4 in the second second battery row unit 2 is connected to the negative electrode copper foil busbar 15 through exposed copper point 5 and negative electrode copper foil connection line 9, and converges to the negative electrode lead-out terminal 24.

[0106] Example 4

[0107] like Figure 12 and Figure 13 As shown, this embodiment provides a back-contact solar cell module, which is similar to the example in Embodiment 3, except that:

[0108] like Figure 12As shown, in this embodiment, the conductive lines of the copper-clad layer 6 of the PCB backplane are provided with three copper foil lead-in lines 21. Each copper foil lead-in line 21 is located between the first conductive unit 10 and the second conductive unit 11, parallel to the positive copper foil busbar 14 and the negative copper foil busbar 15, and passes through the electrode interconnect line 18 connecting the first conductive unit 10 and the second conductive unit 11. One end of the copper foil lead-in line 21 is provided with a lead-in line lead-out contact 22. Each lead-in line lead-out contact 22 is exposed through a lead-in line lead-out contact 27 in the solder mask layer 7, which can be used to test the EL of each area of ​​the component, or to connect diodes to build a bypass diode circuit to further enhance the anti-shielding performance of the component. For example, one end of the positive copper foil busbar 14 is provided with a busbar lead-out contact 26 exposed to the solder mask layer 7, and one end of the adjacent copper foil lead-out line 21 is provided with a lead-out contact 27 exposed to the solder mask layer 7. Then, by applying a reverse voltage between the busbar lead-out contact 26 and the lead-out contact 27, the first battery row cell 1 region can be tested. A diode can also be connected between the busbar lead-out contact 26 and the lead-out contact 27 to provide a parallel bypass diode for the first battery row cell 1 region.

[0109] In summary, the back-contact solar cell module proposed in this invention has the following main advantages:

[0110] 1. Using conventional back-contact solar cells, the solar cells are divided into two halves, which are then used as back-contact solar cell sections. This allows for the construction of a staggered solar cell array using the main back-contact solar cell and the back-contact solar cell sections. When the half-cell is shaded, its internal loss is reduced to 1 / 4 of the original loss of the whole cell, which can effectively reduce the hot spot effect and prevent the temperature of the solar module from rising excessively. At the same time, by removing the rectangular transition area, the silicon wafer cost of the solar module is reduced.

[0111] 2. Using PCB as the backplane of back-contact solar cell modules, the conductive lines made by PCB printed circuit board technology can compensate for the lateral misalignment of the heterogeneous electrodes in the misaligned cell array, so that the spacing between the back-contact cell bodies and between the back-contact cell bodies and the back-contact cell sections in the misaligned cell array is uniformly 2d, which can reduce the process complexity of wiring and improve the consistency of the electrical performance of the cell module.

[0112] Third, the SMT (Surface Mount Technology) process is used between the PCB backplane and the back contact cell array, eliminating the laser correction process of existing technologies, simplifying the welding process of the back contact solar cell module, and improving the production efficiency of the back contact solar cell module.

[0113] Fourth, by setting lead-out contacts, EL testing of components can be achieved during the production process. The lead-out contacts can also be connected to diodes to form bypass diodes, meeting the anti-shading performance requirements of different battery cells.

[0114] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and objectives of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0115] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A back-contact solar cell module, characterized in that, Including the back-contact cell array and the PCB backplane, wherein: The back contact solar cell array includes M first battery row units and M second battery row units arranged alternately along the longitudinal direction. Each first battery row unit includes N back contact solar cell bodies arranged laterally, and the lateral spacing between any two adjacent back contact solar cell bodies is a preset distance 2d. Each back contact solar cell body includes positive electrode main grid lines and negative electrode main grid lines alternately arranged laterally on the backlight surface of the back contact solar cell body, and the lateral spacing between any positive electrode main grid line and an adjacent negative electrode main grid line is a preset distance w. Each second battery row unit includes N-1 back contact solar cell bodies arranged continuously along the lateral direction, and N-1 back contact solar cell bodies respectively arranged in the backlight surface of the back contact solar cell body. The lateral spacing between any two adjacent back contact cell sections at both ends of the back contact cell main body, and the lateral spacing between any back contact cell section and an adjacent back contact cell main body, are all preset distances of 2d; the back contact cell section is a half-cell structure after the back contact cell main body is divided into two; in the back contact cell array, the positive electrode main grid line and the negative electrode main grid line in any first cell row unit are laterally offset from the positive electrode main grid line and the negative electrode main grid line in the adjacent second cell row unit, and the lateral offset interval is d; where M is a positive integer, N is a positive integer greater than 1, and d and w are both positive numbers; The PCB backplane includes an insulating substrate layer, a copper cladding layer, and a solder mask layer arranged sequentially from bottom to top. The copper cladding layer has conductive lines that are electrically connected to the back contact cell array. The PCB backplane is in contact with the back contact cell body and the back light surface of the back contact cell portion in the back contact cell array through the solder mask layer.

2. The back-contact solar cell module according to claim 1, characterized in that, The total number of positive electrode main grid lines and negative electrode main grid lines in any one of the back contact cell segments is half the total number of positive electrode main grid lines and negative electrode main grid lines in the main body of the back contact cell, and the total number of positive electrode main grid lines and negative electrode main grid lines in any one of the main bodies of the back contact cell is an even number.

3. The back-contact solar cell module according to claim 2, characterized in that, In any one of the N-1 back contact cell bodies and two back contact cell portions in the second battery row unit, the back contact cell bodies in the first battery row unit are rotated 180° relative to the back contact cell bodies in the first battery row unit, so that the polarity of any set of misaligned corresponding two electrode main grid lines is opposite. The conductive circuit includes M first conductive units and M second conductive units arranged alternately along the longitudinal direction. Each first conductive unit includes N main conductive groups arranged laterally, and the lateral spacing between any two adjacent main conductive groups is a preset distance of 2d. Each main conductive group includes positive copper foil connecting lines and negative copper foil connecting lines arranged alternately in the lateral direction, and the lateral spacing between any positive copper foil connecting line and an adjacent negative copper foil connecting line is a preset distance w. Each second conductive unit includes N-1 main conductive groups arranged continuously in the lateral direction, and branch conductive groups respectively arranged at both ends of the N-1 main conductive groups. The lateral spacing between any two adjacent main conductive groups and the lateral spacing between any branch conductive group and an adjacent main conductive group are both preset distances of 2d. The branch conductive group is a half-group structure after the main conductive group is divided into two. The positive and negative copper foil connecting lines in the first conductive unit are matched one-to-one with the positive and negative main grid lines in the first battery row unit; the positive and negative copper foil connecting lines in the second conductive unit are matched one-to-one with the positive and negative main grid lines in the second battery row unit; and the lateral misalignment interval between any negative copper foil connecting line in the first conductive unit and the corresponding positive copper foil connecting line in the adjacent second conductive unit is d.

4. The back-contact solar cell module according to claim 2, characterized in that, In any one of the N-1 back contact cell bodies and two back contact cell portions in the second battery row unit, the back contact cell bodies are arranged in the same direction as the back contact cell bodies in the first battery row unit, so that the polarity between any two electrode main grid lines that are misaligned is the same. The conductive circuit includes M first conductive units and M second conductive units arranged alternately along the longitudinal direction. Each first conductive unit includes N main conductive groups arranged laterally, and the lateral spacing between any two adjacent main conductive groups is a preset distance of 2d. Each main conductive group includes positive copper foil connecting lines and negative copper foil connecting lines arranged alternately in the lateral direction, and the lateral spacing between any positive copper foil connecting line and an adjacent negative copper foil connecting line is a preset distance w. Each second conductive unit includes N-1 main conductive groups arranged continuously in the lateral direction, and branch conductive groups respectively arranged at both ends of the N-1 main conductive groups. The lateral spacing between any two adjacent main conductive groups and the lateral spacing between any branch conductive group and an adjacent main conductive group are both preset distances of 2d. The branch conductive group is a half-group structure after the main conductive group is divided into two. The positive and negative copper foil connecting lines in the first conductive unit are matched one-to-one with the positive and negative main grid lines in the first battery row unit; the positive and negative copper foil connecting lines in the second conductive unit are matched one-to-one with the positive and negative main grid lines in the second battery row unit; and the lateral misalignment interval between any negative copper foil connecting line in the first conductive unit and the corresponding laterally misaligned negative copper foil connecting line in the adjacent second conductive unit is d, and the lateral misalignment interval between any positive copper foil connecting line and the corresponding laterally misaligned positive copper foil connecting line in the adjacent second conductive unit is d.

5. The back-contact solar cell module according to claim 3 or 4, characterized in that, The conductive circuit also includes a positive copper foil busbar disposed at the upper end of the first conductive unit at the uppermost end, and a negative copper foil busbar disposed at the lower end of the second conductive unit at the lowermost end. Between any adjacent first conductive unit and second conductive unit, the corresponding negative copper foil connecting lines and positive copper foil connecting lines are connected through electrode interconnect lines to achieve vertical series connection of all first conductive units and second conductive units; wherein, all the positive copper foil connecting lines of the uppermost first conductive unit are connected to the positive copper foil bus bar, and the positive copper foil bus bar is connected to a positive copper foil lead-out line; all the negative copper foil connecting lines of the lowermost second conductive unit are connected to the negative copper foil bus bar, and the negative copper foil bus bar is connected to a negative copper foil lead-out line; Both the positive electrode copper foil busbar and the negative electrode copper foil busbar are provided with busbar lead-out contacts at their ends.

6. The back-contact solar cell module according to claim 5, characterized in that, In any of the first conductive units, a battery cell positioning mark is provided around the perimeter and / or at the four corners of any of the main conductive groups; in any of the second conductive units, the battery cell positioning mark is provided around the perimeter and / or at the four corners of any of the main conductive groups and any of the branch conductive groups.

7. The back-contact solar cell module according to claim 6, characterized in that, The conductive circuit also includes a copper foil lead wire, which is disposed in the row spacing between adjacent first conductive units and second conductive units and passes through and connects with the electrode interconnect; the end of the copper foil lead wire is provided with a lead wire lead-out contact.

8. The back-contact solar cell module according to claim 7, characterized in that, Each of the positive electrode main grid lines is provided with a positive electrode solder joint, and each of the negative electrode main grid lines is provided with a negative electrode solder joint; the solder resist layer includes a second cell positioning mark, solder resist layer lead-out contacts, and several exposed copper points, the exposed copper points matching the layout of the positive electrode solder joints and the negative electrode solder joints in the back contact cell array; the second cell positioning mark matches the layout of the first cell positioning mark; the solder resist layer lead-out contacts include a second busbar lead-out contact and a second lead wire lead-out contact, the second busbar lead-out contact matching the layout of the first busbar lead-out contact, and the second lead wire lead-out contact matching the layout of the first lead wire lead-out contact; One end of the positive copper foil lead wire is connected to the positive copper foil busbar, and the other end is exposed on the PCB backplane surface through the solder mask layer, forming a positive lead-out terminal; one end of the negative copper foil lead wire is connected to the negative copper foil busbar, and the other end is exposed on the PCB backplane surface through the solder mask layer, forming a negative lead-out terminal.

9. A method for preparing a back-contact solar cell module according to any one of claims 1 to 8, characterized in that, include: The back contact cell body is divided into two parts in the horizontal direction, and the resulting half cell structure is used as the back contact cell part. A plurality of the back contact cell bodies and a plurality of the back contact cells are arranged longitudinally and transversely on the solder resist layer to form the back contact cell array on the surface of the solder resist layer. The PCB backplane is soldered to the back contact cell array using SMT technology to assemble the back contact solar cell module.

10. A photovoltaic power generation system, characterized in that, Includes the back-contact solar cell module as described in any one of claims 1 to 8.

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