Photovoltaic module

Abstract

The present application provides a photovoltaic module, which comprises a plurality of solar cell sheets having gaps therebetween, each solar cell sheet having a first surface and a second surface opposite to the first surface. The photovoltaic module further comprises, which are provided on the second surface, a busbar, an insulating member, a plurality of first welding strips electrically connected to the busbar, and a plurality of second welding strips insulated from the busbar. The projection of the busbar in a direction perpendicular to the first surface and on the plane where the first surface is located at least partially overlaps the projection of the gaps in the direction perpendicular to the first surface and on the plane where the first surface is located. The projection of the insulating member in the direction perpendicular to the first surface and on the plane where the first surface is located at least partially overlaps the projection of the gaps in the direction perpendicular to the first surface and on the plane where the first surface is located. The busbar and the solar cell sheets are insulated from each other by means of the insulating member in the direction perpendicular to the first surface and in a projection overlapping region on the plane where the first surface is located. In the present application, optimizing a positional relationship between the welding strips and the busbar improves the reliability and safety of photovoltaic modules.

Description

Photovoltaic module

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese application No. 202510120952.5, filed on January 24, 2025, entitled Photovoltaic module, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the field of photovoltaic technology, in particular, to a photovoltaic module. BACKGROUND

[0004] In today's era, solar energy is attracting much attention due to its considerable potential. Throughout the years, improving the photoelectric conversion efficiency of solar cells has always been at the core of solar cell design and optimization work, and is a key task. In the process of continuous development and evolution of technology, the photovoltaic field has always been pursuing the goal of higher power and higher conversion efficiency per unit area of the module. Among them, the back contact cell module stands out with its unique advantages of no grid lines on the front and no solder strips. However, in the conventional back contact cell module version, the busbar and the solder strip electrically connected to the busbar cumulatively occupy a space of up to 30 mm width of the cell module, and this part of the occupied space cannot directly generate electricity. Due to the presence of these busbars and solder strips, not only the effective generating area of the cell module is reduced, but also the power of the module is limited to a certain extent, and the cost of electricity is reduced.

[0005] Therefore, it is necessary to provide an improved photovoltaic module to overcome or reduce at least part of the shortcomings existing in the prior art. SUMMARY

[0006] To address the aforementioned technical problems, this application provides a photovoltaic module comprising: multiple solar cells, a busbar, an insulator, multiple first solder strips, and multiple second solder strips. The solar cells are spaced apart, and each solar cell has a first surface and a second surface opposite to the first surface. The busbar is disposed on the second surface of the solar cells, and its projection along a direction perpendicular to the first surface in the plane of the first surface at least partially overlaps with the projection of the gap along the same direction perpendicular to the first surface in the plane of the first surface. The insulator is disposed on the second surface of the solar cells, and its projection along a direction perpendicular to the first surface in the plane of the first surface at least partially overlaps with the projection of the gap along the same direction perpendicular to the first surface in the plane of the first surface. The overlapping area of ​​the projections of the busbar and the solar cells along the same direction perpendicular to the first surface in the plane of the first surface is electrically insulated by the insulator. The first solder strips are disposed on the second surface and electrically connected to the busbar; the second solder strips are disposed on the second surface and electrically insulated from the busbar.

[0007] Optionally, the width d of the busbar and the spacing c of the solar cells satisfy the following formula: c+k≤d≤2x+ck, where x is the distance from the edge pad of the solar cell to the edge of the solar cell, and k is a constant.

[0008] Optionally, the photovoltaic module has a front glass; c≤(b-2z-na) / (n-1), where b is the length of the front glass, n is the number of solar cells in a battery string arranged from one end to the other end of the photovoltaic module along the length of the front glass, z is the distance from the edge of the battery string at one end and the other end of the photovoltaic module to the edge of the corresponding front glass, and a is the length of the solar cell.

[0009] Optionally, the second surface of the solar cell is provided with a plurality of fine grid lines, and the constant k satisfies the following formula: k≥2y, where y is the distance between adjacent fine grid lines.

[0010] Optionally, a plurality of fine grid lines are provided on the second surface of the solar cell, and the busbar covers at least one of the fine grid lines located on the second surface of the solar cell.

[0011] Optionally, adhesive dots are further provided on the second surface of the solar cell, and the busbar does not cover the adhesive dots, or partially covers the adhesive dots, or completely covers the adhesive dots.

[0012] Optionally, the adhesive dots bond the solar cell to the first solder strip and / or the second solder strip.

[0013] Optionally, the busbar, the insulating component, and the first solder strip are pre-assembled together; or, the busbar, the insulating component, the first solder strip, and the second solder strip are pre-assembled together.

[0014] Optionally, the insulating element includes insulating tape or an insulating coating.

[0015] Optionally, the insulating tape includes at least one of the following: a whole insulating tape, multiple small insulating pieces, and an insulating tape with openings.

[0016] Optionally, the projection of the busbar in the plane of the second surface along a direction perpendicular to the second surface intersects with both of the solar cells adjacent to the busbar; or, it intersects only with one of the two solar cells adjacent to the busbar.

[0017] Optionally, a portion of the second weld strip spans the gap, or the projection of a portion of the second weld strip along a direction perpendicular to the second surface into the plane containing the second surface does not intersect the gap.

[0018] Optionally, at least a portion of the second solder strip does not contact the insulating element.

[0019] Optionally, in the thickness direction of the photovoltaic module, in the projection area of ​​the busbar, the first solder strip and the second solder strip are located on the same side of the busbar; wherein, the busbar is located at the top, and the insulating member is an insulating tape with an opening, located between the busbar and the first solder strip and the second solder strip, electrically insulating the second solder strip from the busbar, and the first solder strip is electrically connected to the busbar at the opening; or, the insulating member includes a first insulating member and a second insulating member, the first insulating member is located between the busbar and the solar cell, the second insulating member is not on the same side of the busbar as the first insulating member, and the second insulating member is located between the second solder strip and the busbar.

[0020] Optionally, in the thickness direction of the photovoltaic module, in the projected area of ​​the busbar, the first solder strip and the second solder strip are not on the same side of the busbar; wherein, the insulating component and the second solder strip are located between the busbar and the solar cell, the insulating component is located between the second solder strip and the busbar and electrically isolates the second solder strip and the busbar, the first solder strip is located on the top layer, or the insulating component includes a first insulating component and a second insulating component, the first insulating component is located between the first solder strip and the solar cell, the first solder strip is located between the first insulating component and the busbar, and the second insulating component is located between the busbar and the second solder strip.

[0021] Optionally, the bus is an edge bus and / or an intermediate bus.

[0022] Optionally, the length 'a' of the solar cell satisfies the following formula: 30mm ≤ a ≤ 110mm; and / or, the width of the solar cell is between 180mm and 220mm.

[0023] This application significantly reduces the module space occupied by the busbar by concealing it within the back surface of the back-contact cell. This allows for an increase in the size of the solar cells or the spacing between them. Increasing the size of the solar cells increases the light-receiving area, thereby improving power generation. Increasing the spacing between the solar cells optimizes heat dissipation within the module, further enhancing module power and reducing the levelized cost of electricity (LCOE). Furthermore, this application optimizes the positional relationship of the solder strips, reducing the welding difficulty of the busbar, decreasing the risk of short-circuit anomalies, improving process quality control, reducing the defect rate, and enhancing the reliability and safety of the photovoltaic module.

[0024] The above and other objects, advantages and features of this application will become more apparent to those skilled in the art from the following detailed description of specific embodiments of this application in conjunction with the accompanying drawings. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application; those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0026] Figure 1 shows a schematic diagram of a photovoltaic module according to an embodiment of this application;

[0027] Figure 2 shows the positional relationship between adjacent solar cells in more detail;

[0028] Figure 3 shows that the projection of the busbar in the plane of the first surface along the direction perpendicular to the first surface at least partially overlaps with the projection of the gap between adjacent solar cells in the plane of the first surface along the direction perpendicular to the first surface.

[0029] Figure 4 is a partial schematic diagram showing the edge busbar connection method of a photovoltaic module according to an embodiment of this application;

[0030] Figure 5 is a partial cross-sectional view of the photovoltaic module shown in Figure 4 taken along line AA;

[0031] Figure 6 shows a partially enlarged view of the edge busbar in Figure 4;

[0032] Figure 7 shows a partial top view of another embodiment of the edge busbar connection method;

[0033] Figure 8 shows a partial top view of another embodiment of the edge busbar connection method;

[0034] Figure 9 is a partial schematic diagram showing the connection method of the central busbar of a photovoltaic module according to an embodiment of the present application;

[0035] Figure 10 is a partial cross-sectional view of the photovoltaic module shown in Figure 9 along line BB;

[0036] Figure 11 shows a partially enlarged view of the central busbar in Figure 9;

[0037] Figure 12 is a partial schematic diagram showing the connection method of the central busbar of a photovoltaic module according to another embodiment of this application;

[0038] Figure 13 is a partial cross-sectional view of the photovoltaic module shown in Figure 12 taken along the CC line;

[0039] Figure 14 is a partial schematic diagram showing the connection method of the central busbar of a photovoltaic module according to another embodiment of the present application;

[0040] Figure 15 is a partial schematic diagram showing the connection method of the central busbar of a photovoltaic module according to another embodiment of the present application;

[0041] Figure 16 is a partial cross-sectional view of the photovoltaic module shown in Figure 15 along the DD line;

[0042] Figure 17 shows a partial top view of a modified embodiment of the edge busbar connection method;

[0043] Figure 18 shows a partial top view of a modified embodiment of the edge busbar connection method;

[0044] Figure 19 shows a partial top view of a modified embodiment three of the edge busbar connection method;

[0045] Figure 20 shows a partial top view of a modified embodiment of the central busbar connection method;

[0046] Figure 21 shows a partial top view of a modified embodiment of the central busbar connection method;

[0047] Figure 22 shows a schematic diagram of an insulating tape with openings; and

[0048] Figure 23 shows a schematic diagram of an insulating tape with openings in an embodiment of this application. Detailed Implementation

[0049] Embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0050] The accompanying drawings illustrate various structural schematics according to embodiments of the present disclosure. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0051] In the context of this disclosure, when a layer / element is referred to as being "on top of" another layer / element, the layer / element may be directly on top of the other layer / element, or there may be an intermediate layer / element between them. Additionally, if a layer / element is "on top of" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "below" the other layer / element. To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, this application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0052] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise expressly specified. "Several" means one or more, unless otherwise expressly specified.

[0053] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0054] Figure 1 shows a schematic diagram of a photovoltaic module 1 according to an embodiment of the present application; Figure 2 shows the positional relationship between adjacent solar cells in more detail; Figure 3 shows that the projection of the busbar 300 along the direction perpendicular to the first surface 110 in the plane of the first surface 110 at least partially overlaps with the projection of the gap between adjacent solar cells along the direction perpendicular to the first surface 110 in the plane of the first surface 110; Figure 4 is a partial schematic diagram showing the edge busbar connection method of a photovoltaic module 1 according to an embodiment of the present application; Figure 5 is a partial cross-sectional view of the photovoltaic module 1 shown in Figure 4 taken along line AA; Figure 6 shows the edge busbar in Figure 4 in the form of a partial enlarged view; Figure 7 shows a partial top view of another embodiment of the edge busbar connection method; Figure 8 shows a partial top view of yet another embodiment of the edge busbar connection method; Figure 9 is a partial schematic diagram showing the center busbar connection method of a photovoltaic module 1 according to an embodiment of the present application; Figure 10 is a partial cross-sectional view of the photovoltaic module shown in Figure 9 taken along line BB; Figure 11 shows the center busbar in Figure 9 in the form of a partial enlarged view; Figure FIG12 is a partial schematic diagram showing the connection method of the center busbar of a photovoltaic module 1 according to another embodiment of the present application; FIG13 is a partial cross-sectional view of the photovoltaic module 1 shown in FIG12 taken along the CC line; FIG14 is a partial schematic diagram showing the connection method of the center busbar of a photovoltaic module 1 according to another embodiment of the present application; FIG15 is a partial schematic diagram showing the connection method of the center busbar of a photovoltaic module 1 according to yet another embodiment of the present application; FIG16 is a partial cross-sectional view of the photovoltaic module 1 shown in FIG15 taken along the DD line; FIG17 shows the edge busbar... Figure 18 shows a partial top view of a modified embodiment of the flow component connection method; Figure 19 shows a partial top view of a modified embodiment of the edge busbar connection method; Figure 20 shows a partial top view of a modified embodiment of the center busbar connection method; Figure 21 shows a partial top view of a modified embodiment of the center busbar connection method; Figure 22 shows a schematic diagram of an insulating tape with openings; and Figure 23 shows a schematic diagram of an insulating tape with openings in an embodiment of this application.

[0055] As shown in Figures 1 to 3, the photovoltaic module 1 includes multiple solar cells 100, a busbar 300, an insulator 400, multiple first solder ribbons 201, and multiple second solder ribbons 202. Gaps are provided between the solar cells 100, and each solar cell 100 has a first surface 110 (see Figure 5) and a second surface 120 opposite to the first surface 110. The busbar 300 is disposed on the second surface 120 of the solar cell 100. The projection of the busbar 300 along a direction perpendicular to the first surface 110 in the plane of the first surface 110 at least partially overlaps with the projection of the gap between the solar cells 100 along a direction perpendicular to the first surface 110 in the plane of the first surface 110. An insulating member 400 is disposed on the second surface 120 of the solar cell. The gap between the projection of the insulating member 400 along the direction perpendicular to the first surface 110 and the projection of the solar cell 100 in the plane of the first surface 110 at least partially overlaps with the projection of the insulating member 300 along the direction perpendicular to the first surface 110. The overlapping area of ​​the projections of the busbar 300 and the solar cell 100 along the plane of the first surface 110 is insulated by the insulating member 400. A first solder strip 201 is disposed on the second surface 120 and is electrically connected to the busbar 300. A second solder strip 202 is disposed on the second surface 120 and is electrically insulated from the busbar 300.

[0056] Since the light-receiving surface of the solar cell 100 is not obstructed, the busbar does not occupy the space between the solar cells 100, thereby increasing the space utilization rate of the light-receiving surface of the solar cell 100. This allows each solar cell to absorb sunlight to the maximum extent, which not only increases the cell density per unit area and improves the photoelectric conversion efficiency of the photovoltaic module 1, but also makes the front appearance of the cells more aesthetically pleasing. Furthermore, by hiding the busbar on the back surface of the solar cell 100, this application significantly reduces the module space occupied by the busbar, thereby increasing the size of the solar cell 100 or increasing the spacing between the solar cells 100. Increasing the size of the solar cell 100 increases the light-receiving area, thus increasing power generation, while increasing the spacing between the solar cells 100 optimizes the heat dissipation performance inside the module, further increasing the module power and reducing the levelized cost of electricity (LCOE).

[0057] As shown in Figure 1, two or more solar cells 100 can be connected in series to form multiple battery strings. Multiple battery strings can be connected in series, in parallel, or in a series-parallel combination to achieve current collection and output. For example, the connection between multiple solar cells 100 can be achieved through busbars (also known as busbars) and welding strips (also known as welding strips).

[0058] As shown in Figures 2 and 3, the backlighting surface of the solar cell 100 is located on the second surface 120, and the light-facing surface of the solar cell 100 is located on the first surface 110. In the embodiments shown in Figures 2 and 3, each solar cell 100 has an electrode structure on the second surface 120. This electrode structure has a first polarity pad row including multiple first pads and a second polarity pad row including multiple second pads, wherein the polarities of the first polarity pad row and the second polarity pad row are opposite, and the first polarity pad row and the second polarity pad row are alternately spaced in the X direction on the second surface of the solar cell 100. For example, the first pad can be connected to a positive electrode fine grid line, and the second pad can be connected to a negative electrode fine grid line. The first pad can be electrically connected by a first solder ribbon, and the second pad can be electrically connected by a second solder ribbon. It should be understood that the first pad and the second pad are defined only for the purpose of distinguishing pads and solder ribbons of different polarities. For example, the first pad can also be connected to a negative electrode fine grid line, and the second pad can be connected to a positive electrode fine grid line. Optionally, the graphic settings of each pad column in each solar cell 100 can be the same or different.

[0059] In this application, as described above and as shown in Figures 2 and 3, the spacing between adjacent solar cells 100 in the Y direction is c. The width d of the busbar and the spacing c of the solar cells 100 satisfy the following formula: c + k ≤ d ≤ 2x + ck. Where, as shown in Figure 2, x is the distance from the edge pad 150 of the solar cell 100 to the edge of the solar cell, and k is a constant. Optionally, the spacing c can be selected from any value between 0 mm and 3 mm.

[0060] For example, the interlayer spacing c can be 0.2mm, or 0.4mm, or 0.6mm, or 0.8mm, or 1.0mm, or 1.2mm, or 1.4mm, or 1.6mm, or 1.8mm, or 2.0mm, or 2.2mm, or 2.4mm, or 2.6mm, or 2.8mm, or 3.0mm, or any value between any two of the above.

[0061] It should be noted that in the formula c+k≤d≤2x+ck, c+k≤d means that the overlap width between the busbar and the solar cell is greater than or equal to k, i.e., dc≥k. The purpose is threefold: first, to ensure a minimum width for the busbar, guaranteeing the tensile area for welding with the solder strips and reducing the risk of tensile failure; second, to ensure a certain overlap area between the busbar and the solar cell, avoiding misalignment and preventing the busbar from deviating from the solar cell; and third, to increase the overlap area between the busbar and the solar cell, reducing lamination cracking. Furthermore, in the formula d≤2x+ck, the distance from the edge of the busbar to the edge pad is greater than or equal to k (the sum of the distances from each edge to its corresponding edge pad is greater than k), i.e., 2x+cd≥k. The purpose is twofold: first, to ensure a certain distance between the busbar and the edge pads, avoiding solder dross, solder balls, and short circuits caused by soldering adjacent non-standard solder strips; and second, to avoid misalignment of the busbar and prevent overlap between non-standard solder strips and the busbar.

[0062] Furthermore, the photovoltaic module 1 has a front glass; c≤(b-2z-na) / (n-1), where b is the length of the front glass, n is the number of solar cells 100 in a battery string arranged from one end to the other along the length of the front glass, z is the distance from the edge of the battery string at one end and the other end of the photovoltaic module 1 to the edge of the corresponding front glass, and a is the length of the solar cell 100, wherein the distance z≥25.8mm, preferably, the distance z is 26mm. Furthermore, n≥2, preferably, n can be 18, 20, 22, 24, 27, 30, 33, 36, 37, 40, 44, 45, 48, 49, 50, 54, 55, 60, 66, 72, 73, 74, 75, or any value between any two of the above.

[0063] Optionally, the solar cell in this embodiment can be a 2-cell, 3-cell, 4-cell, 5-cell, or 6-cell solar cell. The overall length of the solar cell before separation can be 180mm, 181mm, 182mm, 183mm, 184mm, 185mm, 186mm, 187mm, 188mm, 189mm, 190mm, 191mm, 192mm, 193mm, 194mm, 195mm, 196mm, 197mm, 198mm, or 199mm. 200mm, or 201mm, or 202mm, or 203mm, or 204mm, or 205mm, or 206mm, or 207mm, or 208mm, or 209mm, or 210mm, or 211mm, or 212mm, or 213mm, or 214mm, or 215mm, or 216mm, or 217mm, or 218mm, or 219mm, or 220mm, or any value between any two of the above.

[0064] The length 'a' of the solar cell 100 satisfies the following formula: 30mm ≤ a ≤ 110mm. For example, the length 'a' of the solar cell 100 can be 30mm, 32mm, 35mm, 38mm, 40mm, 42mm, 48mm, 50mm, 52mm, 53mm, 60mm, 64mm, 70mm, 71mm, 80mm, 90mm, 96mm, 100mm, 105mm, 106mm, or 110mm, or any value between any two of the above.

[0065] Furthermore, the width of the solar cell 100 can be between 180mm and 220mm. For example, the width of the solar cell 100 can be 180mm, or 182mm, or 184mm, or 186mm, or 188mm, or 190mm, or 192mm, or 194mm, or 196mm, or 198mm, or 200mm, or 202mm, or 204mm, or 206mm, or 208mm, or 210mm, or 212mm, or 214mm, or 216mm, or 218mm, or 220mm, or any value between any two of the above.

[0066] Optionally, a plurality of fine grid lines are provided on the second surface 120 of the solar cell 100, where the constant k ≥ 2y. In this embodiment, the busbar 300 covers at least one fine grid line on the second surface 120 of the solar cell 100. That is, along the direction perpendicular to the second surface 120 and in the plane where the second surface 120 is located, the busbar is configured to overlap with the fine grid line to a certain extent. The reasons for this configuration are as follows: First, the back of the solar cell is provided with fine grid lines and pads; and the fine grid lines have a height relative to the surface of the solar cell, i.e., the whole is a concave-convex interface. When setting the busbar, the friction can be increased, and the manufacturing offset of the busbar can be reduced. Second, the fine grid lines have a certain height, which relatively elevates the busbar, which is conducive to the filling of the encapsulant film, reduces lamination cracking, and improves the reliability of the module.

[0067] As shown in Figure 2, y is the distance between adjacent fine grid lines. Optionally, 0.05mm≤y≤1mm, and preferably, y can be 0.5mm.

[0068] For example, the distance y can be 0.05mm, or 0.1mm, or 0.15mm, or 0.2mm, or 0.25mm, or 0.3mm, or 0.35mm, or 0.4mm, or 0.45mm, or 0.5mm, or 0.55mm, or 0.6mm, or 0.65mm, or 0.7mm, or 0.75mm, or 0.8mm, or 0.85mm, or 0.9mm, or 0.95mm, or 1mm, or any value between any two of the above.

[0069] In the above case, d≤2x+(b-2z-na) / (n-1)-2y.

[0070] In some embodiments of this application, the busbar 300 includes an edge busbar and a center busbar. As shown in FIG1, in the Y direction, the photovoltaic module 1 has edge solar cells 100, namely a left edge solar cell 160 and a right edge solar cell 170. Each of the edge solar cells 100 is provided with a gap of size c between it and its adjacent solar cell 100 in the Y direction. The spacing between any two adjacent solar cells in the Y direction is also c. The projection of the edge busbar in the plane of the first surface 110 along a direction perpendicular to the first surface 110 at least partially overlaps with the projection of the gap in the plane of the first surface 110 along a direction perpendicular to the first surface 110.

[0071] In some implementations, a battery string array can be configured with multiple battery strings in the Y direction, and a central busbar is provided between the solar cells of adjacent battery strings.

[0072] The following are some implementation methods. For example, in a 72-panel photovoltaic module, each cell string includes 24 solar cells. In this case, the projection of the central busbar in the plane of the first surface 110 along a direction perpendicular to the first surface 110 at least partially overlaps with the projection of the gap between the 12th and 13th solar cells in the cell string in the plane of the first surface 110 along a direction perpendicular to the first surface 110. For example, in a 66-panel photovoltaic module, each cell string includes 22 solar cells. In this case, the projection of the central busbar in the plane of the first surface 110 along a direction perpendicular to the first surface 110 at least partially overlaps with the projection of the gap between the 11th and 12th solar cells in the cell string in the plane of the first surface 110 along a direction perpendicular to the first surface 110. For example, in a 54-panel photovoltaic module, each cell string includes 18 solar cells. In this case, the projection of the central busbar in the plane of the first surface 110 along the direction perpendicular to the first surface 110 at least partially overlaps with the projection of the gap between the 9th and 10th solar cells in the cell string in the plane of the first surface 110 along the direction perpendicular to the first surface 110.

[0073] The following describes in more detail, with reference to Figures 4 to 22, various connection methods of the edge bus and the center bus in this application.

[0074] Figures 4 to 8 illustrate the connection method of the edge bus according to this application.

[0075] Figures 4 to 6 show schematic diagrams of the connection method of the edge busbar 311 according to an embodiment of the present application. In this embodiment, the first solder strip 201 is located on the side of the busbar 311 away from the solar cell. The projection of the edge busbar 311 along the direction perpendicular to the second surface 120 in the plane of the second surface 120 intersects only one of the two solar cells adjacent to the edge busbar 311. At least a portion of the second solder strip 202 does not contact the insulating member 400. In the thickness direction of the photovoltaic module 1, the first solder strip 201 and the second solder strip 202 are not on the same side of the edge busbar 311 in the projection area of ​​the edge busbar 311.

[0076] As shown in Figures 4 to 6, the projections of the edge busbar 311 and the insulating member 400 in the plane of the first surface 110 along the direction perpendicular to the first surface 110 and the gap between the first battery cell 101 and the second battery cell 102 in the plane of the first surface 110 along the direction perpendicular to the first surface 110 at least partially overlap. There is a stacked arrangement between the first battery cell 101, the second battery cell 102, the first solder strip 201, part of the second solder strip 202, the edge busbar 311 and the insulating member 400.

[0077] Specifically, a portion of the second solder strip 202 on the second battery cell 102 does not contact the insulating component 400 and the second battery cell 102, while a portion of the second solder strip 202 connects the first battery cell 101 and the second battery cell 102.

[0078] As shown in Figures 4 and 5, in the projected area of ​​the edge busbar 311, the first solder strip 201 and the second solder strip 202 are not on the same side of the busbar. The first solder strip 201 is located on the top layer, and multiple second solder strips 202 are disposed between the insulating component 400 and the solar cell, so that the multiple second solder strips 202 are electrically insulated from the edge busbar 311 through the insulating component 400, avoiding short circuits caused by electrical connection between the second solder strips 202 and the edge busbar 311. In this embodiment, as shown in Figure 5, the first solder strip 201 is located above the edge busbar 311. This arrangement is beneficial to the welding operation of the edge busbar 311. Since the relevant welding equipment is quite mature, it can effectively ensure the accuracy and stability of welding, thus providing solid technical support and feasibility for large-scale mass production. On the other hand, in terms of quality inspection, this arrangement allows for the smooth implementation of the AI ​​inspection process after welding. With the help of advanced AI inspection technology, the welding effect of the busbar can be accurately confirmed, and defective products can be removed in a timely and effective manner, greatly improving the overall quality and reliability of the product.

[0079] Figure 7 illustrates another embodiment of the edge busbar 312 connection method. Unlike the embodiment shown in Figure 6, the first solder strip 201 is located between the second surface 120 of the solar cell and the busbar, specifically, between the edge busbar 312 and the insulating member 400. This arrangement facilitates bonding the first solder strip 201, the second solder strip 202, and the edge busbar 312 through the insulating member 400, thus facilitating the formation of a pre-assembled component.

[0080] Figure 8 illustrates another embodiment of the connection method of the edge busbar 313. In this embodiment, adhesive dots are further provided on the second surface 120 of the solar cell 100, and the adhesive dots bond the solar cell 100 to the first solder ribbon 201 and / or the second solder ribbon 202. Optionally, the adhesive used for the adhesive dots can be a thermosetting adhesive or a photocurable adhesive, such as a UV-curable adhesive.

[0081] The busbar may not cover the adhesive dots, or may partially cover the adhesive dots, or may completely cover the adhesive dots. Specifically, in the embodiment shown in FIG8, the placement of the edge busbar 313 is slightly different from that shown in FIG7. The edge busbar 313 covers part of the adhesive dots (marked by circle 180 in FIG7) or may cover all of the adhesive dots, that is, the edge busbar 313 is closer to the pads of the first battery cell 101.

[0082] Specifically, in this embodiment, the edge busbar 313 can be positioned above the solder strip at the adhesive dot location and welded thereto. This configuration, with the edge busbar 313 positioned above, significantly improves the accuracy of solder strip placement. Since the beginning and end of the solder strip are not affected by the heightening effect of the busbar, the stability of the entire process is enhanced.

[0083] Figures 9 to 16 illustrate some connection methods of the central bus according to this application.

[0084] Figures 9 to 11 show schematic diagrams of the connection method of the central busbar 321 according to an embodiment of the present application. In this embodiment, the first solder strip 201 is located on the side of the busbar away from the solar cell, and in the thickness direction of the photovoltaic module 1, the first solder strip 201 and the second solder strip 202 are not on the same side of the projected area of ​​the central busbar 321. As shown in Figures 9 to 11, the third battery cell 103 and the fourth battery cell 104 are arranged at intervals. The second surface 120 of the third battery cell 103 and the fourth battery cell 104 are respectively provided with a plurality of first solder strips 201 and a plurality of second solder strips 202. The central busbar 321 and the insulating member 400 are arranged at the second surface 120. The projection of the central busbar 321 and the insulating member 400 in the plane of the first surface 110 along the direction perpendicular to the first surface 110 overlaps at least partially with the projection of the third battery cell 103 and the fourth battery cell 104 in the plane of the first surface 110 along the direction perpendicular to the first surface 110. There is a stacked arrangement between the third battery cell 103, the fourth battery cell 104, the first solder strips 201, part of the second solder strips 202, the central busbar 321 and the insulating member 400.

[0085] As shown in Figures 10 and 11, specifically, a plurality of first welding strips 201 are disposed above the central busbar 321, across the central busbar 321, and electrically connected to the central busbar 321. A plurality of second welding strips 202 are disposed on the left and right sides of the insulating member 400 and do not contact the insulating member 400, so that the plurality of second welding strips 202 are electrically insulated from the central busbar 321.

[0086] In this embodiment, as shown in Figure 10, the first weld strip 201 is located above the central busbar 321. This arrangement facilitates the welding operation of the central busbar 321. Since current welding equipment is quite mature, it effectively ensures the accuracy and stability of the welding, thus providing solid technical support and feasibility for large-scale mass production. Furthermore, in terms of quality inspection, this arrangement allows for smooth implementation of the AI ​​inspection process after welding. With the help of advanced AI inspection technology, the welding effect of the busbar can be accurately confirmed, and defective products can be promptly and effectively removed, greatly improving the overall quality and reliability of the product. It should be noted that although the insulating component 400 does not cover the adhesive dots in this embodiment, in other embodiments not shown in this application, the insulating component 400 may cover the adhesive dots.

[0087] Furthermore, in the embodiments shown in Figures 9 to 11, the projection of the central busbar 321 along a direction perpendicular to the second surface 120 into the plane containing the second surface 120 intersects with both solar cells adjacent to the busbar 321. It should be understood that, for the edge busbars, the projection of the edge busbar along a direction perpendicular to the second surface 120 into the plane containing the second surface 120 can also intersect with both solar cells adjacent to the edge busbar.

[0088] Figures 12 and 13 illustrate another embodiment of the connection method of the central busbar 322. In this embodiment, unlike the embodiments shown in Figures 9 to 11, a portion of the second solder strip 202 is disposed below the insulating member 400. This allows the central busbar 322 (busbar 300) and the first solder strip to be pre-assembled, avoiding twisting, offset, or fixation abnormalities during solder strip placement, thus improving placement accuracy and manufacturing stability.

[0089] Figure 14 illustrates the connection method of the central busbar of a photovoltaic module 1 according to another embodiment of this application. In this embodiment, the stacking relationship between the third cell 103, the fourth cell 104, the second solder ribbon 202, the central busbar 322, and the insulator 400 is the same as that shown in Figures 9 to 11. The difference is that the first solder ribbon 201 is located between the second surface 120 of the solar cell and the busbar, specifically, between the central busbar 322 and the insulator 400. Furthermore, the projection of the central busbar 322 along a direction perpendicular to the second surface 120 into the plane of the second surface 120 intersects with the two solar cells adjacent to the central busbar 322, and the second solder ribbon 202 does not contact the insulator 400. That is, in this embodiment, the insulator 400 is located between the first solder ribbon 201 and the solar cell, and electrically isolates the first solder ribbon 202 and the solar cell.

[0090] Figures 15 and 16 illustrate another embodiment of the connection method of the central busbar 323. In this embodiment, the first solder strip 201 is located between the second surface of the solar cell and the central busbar 323, and the projection of the central busbar 323 along a direction perpendicular to the second surface 120 in the plane of the second surface 120 intersects only one of the two solar cells adjacent to the central busbar 323. At least a portion of the second solder strip 202 does not contact the insulator 400. The stacking order between the third cell 103, the fourth cell 104, the first solder strip 201, a portion of the second solder strip 202, the central busbar 323, and the insulator 400 is similar to the embodiment shown in Figure 14. Unlike the embodiment shown in Figure 14, in this embodiment, a portion of the second solder strip 202 directly contacts the insulator 400; specifically, a portion of the second solder strip 202 is disposed below the insulator 400. Furthermore, in the thickness direction of the photovoltaic module 1, in the projection area of ​​the busbar 323, the first solder strip 201 and the second solder strip 202 are located on the same side of the busbar. It should be noted that, in this embodiment, the projections of the central busbar 323 and the insulating member 400 along the direction perpendicular to the second surface 120 and in the plane containing the second surface 120 only partially overlap with the projections of the third cell 103 and the fourth cell 104 along the direction perpendicular to the second surface 120 and in the plane containing the second surface 120, as shown more clearly in Figure 16. The insulating member 400 only covers the edge of the third cell 103 and a portion of the gap between the third cell 103 and the fourth cell 104. In this embodiment, the central busbar 323 is positioned above the insulating component 400. This arrangement facilitates the welding operation of the central busbar 323, as current welding equipment is quite mature and can effectively ensure the accuracy and stability of the welding, thus providing solid technical support and feasibility for large-scale mass production. On the other hand, in terms of quality inspection, this arrangement allows for the smooth implementation of the AI ​​inspection process after welding. With the help of advanced AI inspection technology, the welding effect of the busbar can be accurately confirmed, and defective products can be removed in a timely and effective manner, greatly improving the overall quality and reliability of the product.

[0091] In addition, it should be noted that a portion of the second solder strip 202 spans the gap between adjacent solar cells, or the projection of a portion of the second solder strip 202 along a direction perpendicular to the second surface 120 in the plane containing the second surface 120 does not intersect with the gap between adjacent solar cells.

[0092] Optionally, the busbar, insulator 400, and first solder strip 201 can be pre-assembled. This arrangement effectively avoids many potential problems arising during the production of the photovoltaic module 1. For example, when using conventional processes for solder strip placement, solder strip twisting often occurs. This may be due to uneven external forces or equipment precision deviations during operation, causing the solder strip to fail to be placed in the predetermined straight shape. Misalignment is also common, causing the solder strip to deviate from the predetermined welding position, thus affecting welding accuracy and electrical connection reliability. Furthermore, there may be instances of insecure placement, where the solder strip cannot stably maintain its set position after placement and is prone to movement or shaking. However, by pre-assembling the components, the first solder strip, insulator, and busbar are securely assembled before the second solder strip is placed, providing a more accurate reference and stable foundation for the placement of the second solder strip, improving the accuracy of solder strip placement, and thus enhancing the stability of the entire production process. It is particularly important to note that when the first solder strip is placed, if there is a busbar underneath, there is actually an additional interface. This will increase the complexity and instability of the process to some extent. For example, it may lead to problems such as uneven heat transfer and unreasonable stress distribution during the welding process. Pre-forming the assembly can effectively overcome these drawbacks, optimize the production process, and improve process stability.

[0093] Furthermore, the busbar, insulator, first solder strip, and second solder strip can be pre-assembled. This arrangement provides similar advantages to those described above during the production of photovoltaic module 1, which will not be elaborated further here.

[0094] Optionally, in the embodiments described above, the insulating element 400 includes insulating tape, and the insulating element 400 may be selected from one or more of EVA, EPE, POE, and PET.

[0095] Optionally, the insulating component 400 may include an insulating adhesive coating (not shown), wherein the insulating adhesive coating can be precisely printed onto the solar cell using an insulating adhesive printing process, thereby enabling the solar cell to acquire the relevant properties and functions imparted by the insulating adhesive coating.

[0096] Optionally, the insulating tape may include at least one of the following: a whole insulating tape, multiple small pieces of insulating tape, and insulating tape with openings.

[0097] Figure 17 shows a partial top view of a modified embodiment of the edge busbar connection method. In this embodiment, the first solder strip 201 is located on the side of the busbar away from the solar cell, and the projection of the edge busbar along a direction perpendicular to the second surface 120 in the plane containing the second surface 120 intersects only one of the two solar cells adjacent to the edge busbar. At least a portion of the second solder strip 202 does not contact the insulating member 400. Furthermore, in the thickness direction of the photovoltaic module 1, the first solder strip 201 and the second solder strip 202 are not on the same side of the busbar projection area. In the embodiment shown in Figure 17, the insulating member 400 includes a first insulating member and a second insulating member. The first insulating member is an insulating adhesive coating, and the second insulating member is a small piece of insulating adhesive. As shown in Figure 17, the first battery cell 101 and the second battery cell 102 are arranged at intervals. The second surfaces of the first battery cell 101 and the second battery cell 102 are respectively provided with a plurality of first solder strips 201 and a plurality of second solder strips 202. The edge busbar 314 and the insulating adhesive block 330 are arranged at the second surface 120. The projections of the edge busbar 314 and the insulating adhesive block 330 in the plane of the first surface 110 along the direction perpendicular to the first surface 110 and the gap between the first battery cell 101 and the second battery cell 102 in the plane of the first surface 110 along the direction perpendicular to the first surface 110 at least partially overlap. There is a stacked arrangement between the first battery cell 101, the second battery cell 102, the first solder strips 201, part of the second solder strips 202, the edge busbar 314 and the insulating adhesive block 330. Specifically, as shown in Figure 17, multiple second solder strips 202 are disposed between the insulating adhesive block 330 and the solar cell, such that the multiple second solder strips 202 are electrically insulated from the edge busbar 314 through the insulating adhesive block 330, preventing short circuits caused by electrical connection between the second solder strips 202 and the edge busbar 314. The edge busbar 314 is disposed between the insulating adhesive block 330 and the first solder strips 201, wherein the first solder strips 201 are used to electrically connect the first pad of the first solar cell 101 to the edge busbar 314. In this embodiment, as shown in Figure 17, the first solder strips 201 are located above the edge busbar 314. Furthermore, since the surfaces of the first solar cell 101 and the second solar cell 102 are provided with an insulating adhesive coating, the edge busbar 314, when disposed on the surfaces of the first solar cell 101 and the second solar cell 102, cannot be directly electrically connected to the surfaces of the first solar cell 101 and the second solar cell 102. In other words, the insulating adhesive coating can electrically insulate the second solder strip 202 and the first solder strip 201, which is electrically connected to the edge busbar 314, from the solar cell.This design avoids the risk of short circuits or arc damage that may be caused by direct electrical connection between the edge busbar 314 and the surface of the solar cell. On the other hand, from the perspective of production process optimization, the insulating adhesive coating replaces part of the insulating tape, thereby effectively reducing the amount of insulating tape used and correspondingly simplifying the related complex process steps.

[0098] Figure 18 shows a partial top view of a modified embodiment of the edge busbar connection method. In this embodiment, the first solder strip 201 is located between the second surface of the solar cell and the busbar. The projection of the edge busbar 315 along a direction perpendicular to the second surface 120 in the plane containing the second surface 120 intersects only one of the two solar cells adjacent to the edge busbar. At least a portion of the second solder strip 202 does not contact the insulator 400. Furthermore, in the thickness direction of the photovoltaic module 1, the first solder strip 201 and the second solder strip 202 are not on the same side of the projection area of ​​the edge busbar 315. In addition, the insulator 400 includes a first insulator and a second insulator. The first insulator is located between the first solder strip 201 and the solar cell, and the first solder strip 201 is located between the first insulator and the busbar. The second insulator is located between the busbar and the second solder strip 202. In the embodiment shown in Figure 18, the first insulator is an insulating adhesive coating, and the second insulator is a small piece of insulating adhesive. As shown in Figure 18, the first battery cell 101 and the second battery cell 102 are arranged at intervals. The second surfaces of the first battery cell 101 and the second battery cell 102 are respectively provided with a plurality of first solder strips 201 and a plurality of second solder strips 202. The edge busbar 315 and the insulating adhesive block 330 are arranged on the second surface 120. The projections of the edge busbar 315 and the insulating adhesive block 330 in the plane of the first surface 110 along the direction perpendicular to the first surface 110 overlap with the projections of the first battery cell 101 and the second battery cell 102 in the plane of the first surface 110 along the direction perpendicular to the first surface 110. The first battery cell 101, the second battery cell 102, the first solder strips 201, part of the second solder strips 202, the edge busbar 315 and the insulating adhesive block 330 are stacked. Specifically, as shown in Figure 18, insulating adhesive blocks 330 are disposed between the plurality of second solder strips 202 and the edge busbar 315, so that the plurality of second solder strips 202 are electrically insulated from the edge busbar 315 by the insulating adhesive blocks 330, thus preventing short circuits caused by electrical connection between the second solder strips 202 and the edge busbar 315. A first solder strip 201 is disposed between the solar cell and the edge busbar 315 and is electrically connected to the edge busbar 315. The first solder strip 201 is used to electrically connect the first pad of the first solar cell 101 to the edge busbar 315. In this embodiment, since the surfaces of the first battery cell 101 and the second battery cell 102 are provided with an insulating adhesive coating, the edge busbar 315 and the first solder ribbon 201, when disposed on the surfaces of the first battery cell 101 and the second battery cell 102, cannot be directly electrically connected to the surfaces of the first battery cell 101 and the second battery cell 102. In other words, the insulating adhesive coating can electrically insulate the edge busbar 314 and the first solder ribbon 201 electrically connected to the edge busbar 314 from the solar cell, thereby avoiding short circuits between the busbar and the solar cell through the printing of the insulating adhesive coating.This design avoids the risk of short circuits or arc damage that may be caused by direct electrical connection between the edge busbar 315 and the first solder strip 201 and the surface of the solar cell. On the other hand, from the perspective of production process optimization, the insulating adhesive coating replaces part of the insulating tape, thereby effectively reducing the amount of insulating tape used and correspondingly simplifying the related complex process steps.

[0099] Figure 19 shows a partial top view of a modified embodiment three of the edge busbar connection method. In this embodiment, the first solder strip 201 is located on the side of the busbar away from the solar cell, and the projection of the edge busbar along a direction perpendicular to the second surface 120 in the plane containing the second surface 120 intersects only one of the two solar cells adjacent to the edge busbar. At least a portion of the second solder strip 202 does not contact the insulator 400, and in the thickness direction of the photovoltaic module 1, the first solder strip 201 and the second solder strip 202 are located on the same side of the busbar in the projected area. Furthermore, the insulator 400 includes a first insulator and a second insulator. The first insulator is located between the busbar and the solar cell, and the second insulator is located on a different side of the busbar than the first insulator. The second insulator is located between the second solder strip 202 and the busbar. Unlike the embodiment in Figure 18, the first solder strip 201 is disposed above the edge busbar 316 and is electrically connected to the edge busbar 316. This setup offers several advantages. First, it facilitates the welding of the edge busbar 316. Since current welding equipment is quite mature, it effectively ensures the accuracy and stability of the welding, thus providing solid technical support and feasibility for large-scale mass production. Second, in terms of quality inspection, this setup allows for the smooth implementation of AI inspection processes after welding. With the help of advanced AI inspection technology, the welding effect of the busbar can be accurately confirmed, and defective products can be promptly and effectively removed, greatly improving the overall quality and reliability of the product.

[0100] Figure 20 shows a partial top view of a modified embodiment of the central busbar connection method. In this embodiment, the first solder strip 201 is located on the side of the busbar away from the solar cell, and the projection of the central busbar in the plane of the second surface 120 along a direction perpendicular to the second surface 120 intersects with the two solar cells adjacent to the central busbar. In the thickness direction of the photovoltaic module 1, in the projection area of ​​the busbar, the first solder strip 201 and the second solder strip 202 are not on the same side of the busbar. In the embodiment shown in Figure 20, the insulating member 400 includes a first insulating member and a second insulating member. The first insulating member is an insulating adhesive coating, and the second insulating member is a small piece of insulating adhesive. As shown in Figure 20, the third battery cell 103 and the fourth battery cell 104 are spaced apart. The second surface 120 of the third battery cell 103 and the fourth battery cell 104 are respectively provided with a plurality of first welding strips 201 and a plurality of second welding strips 202. The central busbar 324 and the insulating adhesive block 330 are provided on the second surface 120. The projection of the central busbar 324 and the insulating adhesive block 330 in the plane of the first surface 110 along the direction perpendicular to the first surface 110 overlaps at least partially with the projection of the gap between the third battery cell 103 and the fourth battery cell 104 in the plane of the first surface 110 along the direction perpendicular to the first surface 110. There is a stacked arrangement between the third battery cell 103, the fourth battery cell 104, the first welding strips 201, the second welding strips 202, the central busbar 324 and the insulating adhesive block 330. As shown in Figure 20, multiple first solder strips 201 are disposed above the central busbar 324, making the first solder strips 201 electrically connected to the central busbar 324. Multiple second solder strips 202 are disposed between the insulating adhesive block 330 and the solar cell, and the second solder strips 202 are electrically insulated from the central busbar 324 by the insulating adhesive block 330. As shown in Figure 20, the insulating adhesive block 330 is disposed below the central busbar 324, between the second solder strips 202 and the central busbar 324. Furthermore, since the surfaces of the first solar cell 101 and the second solar cell 102 are coated with an insulating adhesive layer, in areas where the insulating adhesive block 330 is not disposed, direct electrical connection between the central busbar 324 and the solar cell is avoided, preventing short circuits.

[0101] Figure 21 shows a partial top view of a modified embodiment of the central busbar connection method. In this embodiment, the second solder strip 202 is located between the second surface of the solar cell and the busbar, and in the thickness direction of the photovoltaic module 1, in the projected area of ​​the busbar, the first solder strip 201 and the second solder strip 202 are located on the same side of the busbar. In the embodiment shown in Figure 21, the insulating member 400 includes a first insulating member and a second insulating member. The first insulating member is an insulating adhesive coating, and the second insulating member is an insulating adhesive block. Unlike the embodiment in Figure 20, as shown in Figure 21, the first solder strip 201 is disposed below the central busbar 325 and electrically connected to the central busbar 325. At the same time, it is electrically insulated from the solar cell by the insulating adhesive coating on the surface of the solar cell. That is, the insulating adhesive coating can electrically insulate the second solder strip 202 and the first solder strip 201 electrically connected to the central busbar 324 from the solar cell, and the insulating adhesive block can electrically insulate the second solder strip 202 from the central busbar 324.

[0102] Figure 22 shows a schematic diagram of an insulating tape 410 with openings at the edge busbar. As shown in Figure 22, the insulating tape 410 with openings is used to electrically insulate the second solder strip 202 from the busbar and to electrically connect the first solder strip 201 to the busbar, wherein the insulating perforated tape 410 is provided with holes 401. Figure 23 shows a schematic diagram of an insulating tape with openings in an embodiment of this application. As shown in Figure 23, in this embodiment, a portion of the second solder strip 202 is located between the second surface of the solar cell and the busbar. The busbar 318 is located at the top. The insulating tape 410 with openings is located between the busbar 318 and the first solder strip 201 and the second solder strip 202, electrically insulating the second solder strip 202 from the busbar 318. The first solder strip 201 is electrically connected to the busbar 318 at the opening. The projection of the busbar along the direction perpendicular to the second surface 120 in the plane of the second surface 120 intersects only one of the two solar cells adjacent to the busbar. At least a portion of the second solder strip 202 does not contact the insulating tape 400. In the thickness direction of the photovoltaic module 1, in the projection area of ​​the busbar 324, the first solder strip 201 and the second solder strip 202 are located on the same side of the busbar. First battery cell 101 and second battery cell 102 are spaced apart. The second surfaces 120 of the first battery cell 101 and second battery cell 102 are respectively provided with multiple first solder strips 201 and multiple second solder strips 202. An edge busbar 318 and insulating perforated tape 410 are disposed on the second surface 120. The projections of the edge busbar 318 and insulating perforated tape 410 in the plane of the first surface 110 perpendicular to the first surface 110 at least partially overlap with the projections of the first battery cell 101 and second battery cell 102 in the plane of the first surface 110 perpendicular to the first surface 110. The first battery cell 101, second battery cell 102, first solder strips 201, some of the second solder strips 202, edge busbar 318, and insulating perforated tape 410 are stacked. As shown in Figure 23, multiple second solder ribbons 202 are disposed between the insulating perforated tape 410 and the solar cell. The insulating perforated tape 410 has no holes at the contact points with the second solder ribbons 202, ensuring electrical insulation between the second solder ribbons 202 and the edge busbar 318, thus preventing short circuits caused by electrical connection between the second solder ribbons 202 and the edge busbar 318. Similarly, multiple first solder ribbons 201 are disposed between the insulating perforated tape 410 and the solar cell. The insulating perforated tape 410 has holes 401 at the contact points with the first solder ribbons 201, allowing the multiple first solder ribbons 201 to be electrically connected to the edge busbar 318 through the holes 401, thereby electrically connecting the first pad of the first solar cell 101 to the edge busbar 318.In this embodiment, as shown in FIG23 and as described above, since the insulating perforated tape 410 has holes 401 at the position where it contacts the first solder strip 201, the first solder strip 201 can directly contact the edge busbar 318 through the holes 401 of the insulating perforated tape 410 to form an electrical connection. It should be noted that, similar to the previous embodiment, the insulating component 400 includes an insulating adhesive coating, and the first solder strip 201 and the second solder strip 202 are electrically insulated from the solar cell through the insulating adhesive coating.

[0103] It should be noted that, in the embodiments shown in Figures 17 to 23, similarly, the busbar and the insulating component, and the first solder strip 201 can be pre-assembled; or, the busbar and the insulating component, the first solder strip 201, and the second solder strip 202 can be pre-assembled.

[0104] This application significantly reduces the module space occupied by the busbar by concealing it on the back of the back-contact cell. This allows for an increase in the size of the solar cells or an increase in the spacing between the solar cells. Increasing the size of the solar cells increases the light-receiving area, thereby increasing power generation. Increasing the spacing between the solar cells optimizes heat dissipation within the module, further improving module power and reducing the levelized cost of electricity (LCOE). Furthermore, this application optimizes the positional relationship of the solder strips, reducing the welding difficulty of the busbar, decreasing the risk of short-circuit anomalies, improving process quality control, reducing the defect rate, and enhancing the reliability and safety of the solar cells.

[0105] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "one example," "some embodiments," or "preferred embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0106] The embodiments of this application have been described in detail above. However, aspects of this application are not limited to the embodiments described above. Various modifications and substitutions can be applied to the above embodiments without departing from the scope of this application.

Claims

1. A photovoltaic module, wherein, The photovoltaic module comprises: a plurality of solar cell pieces, gaps being arranged between the solar cell pieces, each of the solar cell pieces having a first surface and a second surface opposite to the first surface; a busbar arranged on the second surface of the solar cell pieces, a projection of the busbar in a plane in which the first surface is located along a direction perpendicular to the first surface at least partially overlaps with a projection of the gaps in the plane along the direction perpendicular to the first surface; an insulating piece arranged on the second surface of the solar cell pieces, a projection of the insulating piece in the plane along the direction perpendicular to the first surface at least partially overlaps with the projection of the gaps in the plane along the direction perpendicular to the first surface, and a coincident area of the busbar and the solar cell pieces in the plane along the direction perpendicular to the first surface is electrically insulated by the insulating piece; a plurality of first solder strips arranged on the second surface and electrically connected with the busbar; and a plurality of second solder strips arranged on the second surface and electrically insulated from the busbar. A width d of the busbar and a piece spacing c of the solar cell pieces satisfy a formula: c+k≤d≤2x+c-k, where x is a distance from an edge pad of the solar cell piece to an edge of the solar cell piece, and k is a constant.

2. The photovoltaic module of claim 1, wherein, The photovoltaic module has a front glass, and c≤(b-2z-na) / (n-1), where b is a length of the front glass, n is a number of the solar cell pieces in one cell string arranged along a direction of the length of the front glass from one end of the photovoltaic module to the other end, z is a distance from an edge of the cell string at the one end and the other end of the photovoltaic module to an edge of the corresponding front glass, and a is a length of the solar cell piece.

3. The photovoltaic module of claim 2, wherein, The second surface of the solar cell piece is provided with a plurality of fine grid lines, and a constant k satisfies a formula: k≥2y, where y is a distance between adjacent fine grid lines.

4. The photovoltaic module of claim 2, wherein, The second surface of the solar cell piece is provided with a plurality of fine grid lines, and the busbar covers at least one fine grid line on the second surface of the solar cell piece.

5. The photovoltaic module according to any of claims 1 to 4, wherein, The second surface of the solar cell piece is further provided with an adhesive dot, and the busbar does not cover the adhesive dot, partially covers the adhesive dot, or completely covers the adhesive dot.

6. The photovoltaic module according to any of claims 1 to 4, wherein, The adhesive dot bonds the solar cell piece with the first solder strip and / or the second solder strip.

7. The photovoltaic module of claim 6, wherein, The busbar, the insulating piece, the first solder strip, or the busbar, the insulating piece, the first solder strip, and the second solder strip are a pre-assembled body.

8. The photovoltaic module according to any of claims 1 to 7, wherein, The insulating piece comprises an insulating adhesive tape or an insulating adhesive coating.

9. The photovoltaic module of any of claims 1 to 7, wherein, The insulating adhesive tape comprises at least one of an entire insulating adhesive tape, a plurality of insulating adhesive small pieces, and an insulating adhesive tape with openings.

10. The photovoltaic module of claim 9, wherein, ​ 11. The photovoltaic module of any of claims 1 to 10, wherein, The projection of the busbar in the plane in which the second surface lies in the direction perpendicular to the second surface intersects with two of the solar cell pieces adjacent to the busbar; or, only one of the two of the solar cell pieces adjacent to the busbar.

12. The photovoltaic module of any of claims 1 to 11, wherein, Part of the second solder strip spans the gap, or part of the second solder strip does not intersect with the gap in the projection of the second surface in the plane in which the second surface lies in the direction perpendicular to the second surface.

13. The photovoltaic module of any of claims 1 to 11, wherein, At least part of the second solder strip does not contact the insulating piece.

14. The photovoltaic module of any of claims 1 to 13, wherein, In the thickness direction of the photovoltaic module, the projection area of the busbar, the first solder strip and the second solder strip are located on the same side of the busbar; wherein, The busbar is located at the topmost position, the insulating piece is an insulating tape with an opening, located between the busbar and the first solder strip and the second solder strip, electrically insulating the second solder strip and the busbar, and the first solder strip and the busbar are electrically connected at the opening, Or, the insulating piece includes a first insulating piece and a second insulating piece, the first insulating piece is located between the busbar and the solar cell piece, and the second insulating piece is not located on the same side of the busbar as the first insulating piece, and the second insulating piece is located between the second solder strip and the busbar.

15. The photovoltaic module of any of claims 1 to 13, wherein, In the thickness direction of the photovoltaic module, the projection area of the busbar, the first solder strip and the second solder strip are not located on the same side of the busbar; wherein, The insulating piece and the second solder strip are located between the busbar and the solar cell piece, the insulating piece is located between the second solder strip and the busbar and electrically isolates the second solder strip and the busbar, and the first solder strip is located at the topmost position, Or, the insulating piece includes a first insulating piece and a second insulating piece, the first insulating piece is located between the first solder strip and the solar cell piece, the first solder strip is located between the first insulating piece and the busbar, and the second insulating piece is located between the busbar and the second solder strip.

16. The photovoltaic module of any of claims 1 to 15, wherein, The busbar is an edge busbar and / or an intermediate busbar.

17. The photovoltaic module of any of claims 1 to 16, wherein, The length a of the solar cell piece satisfies the following formula: 30mm≤a≤110mm; and / or the width of the solar cell piece is between 180mm and 220mm.

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