Back contact solar cell module

Abstract

The application discloses a back contact solar cell module, comprising a plurality of back contact solar cells arranged along a first direction and a solder strip extending along the first direction and interconnecting the back contact solar cells, the back surface of the back contact solar cell has a plurality of groups of pads arranged along a second direction, each group of pads has a plurality of pads arranged along the first direction, the first direction and the second direction are perpendicular to each other, the solder strip connecting adjacent back contact solar cells is connected to the pads closest to each other of the adjacent back contact solar cells, respectively, the part of the solder strip between the pair of pads closest to each other has an isolation layer between the pair of adjacent back contact solar cells, the isolation layer continuously extends from the pads closest to each other to the edges of the pair of back contact solar cells adjacent to each other along the first direction. Due to the blocking of the isolation layer, no physical connection is formed between the part of the solder strip and the electrode below the isolation layer, reducing the risk of the solder strip pulling out the electrode at the edge of the back contact solar cell.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, specifically to a back-contact solar cell module. Background Technology

[0002] In a back-contact solar cell, both the positive and negative electrodes are located on the back-shielded side. The unobstructed light-receiving side increases optical absorption. Multiple back-contact solar cells are interconnected to form a back-contact solar cell string, which can then be packaged into a back-contact solar cell module.

[0003] In related technologies, back-contact solar cells are typically connected in series using solder ribbons. However, there is a high risk that the main grid near the edge pads of the cell may be pulled off by the solder ribbons. Utility Model Content

[0004] This invention provides a back-contact solar cell module that reduces the risk of the main grid near the edge pads of the cell being pulled off by the solder strip.

[0005] The back-contact solar cell module of this utility model includes multiple back-contact solar cells arranged along a first direction and solder strips extending along the first direction and interconnecting the back-contact solar cells. The back side of the back-contact solar cell has multiple sets of solder pads spaced apart along a second direction. Each set of solder pads has multiple solder pads spaced apart along the first direction. The first direction and the second direction are perpendicular to each other. The solder strips connecting adjacent back-contact solar cells in series are respectively connected to the solder pads closest to each other of the adjacent back-contact solar cells. The portion of the solder strip located between the pair of solder pads closest to each other has an isolation layer between it and the pair of adjacent back-contact solar cells. The isolation layer extends continuously along the first direction from the solder pads closest to each other to the edges of the pair of back-contact solar cells adjacent to each other.

[0006] In some implementations, along the extension path of the insulating layer, all electrodes between the closest pads of the adjacent back-contact solar cells and the edges of the pair of back-contact solar cells adjacent to each other are covered by the insulating layer.

[0007] In some implementations, the isolation layer is centered on the centerline of the pair of pads closest to each other along a first direction, and the minimum width of the isolation layer in a second direction is 1.5-2.5 mm.

[0008] In some embodiments, the back-contact solar cell includes a first bus electrode and a second bus electrode of different conductivity types, the first bus electrode and the second bus electrode being formed on the back side of the back-contact solar cell, the first bus electrode and the second bus electrode extending parallel to each other in a first direction and alternately arranged in a second direction.

[0009] In some embodiments, the back-contact solar cell further includes a first finger electrode of the same conductivity type as the first bus electrode and connected thereto, and a second finger electrode of the same conductivity type as the second bus electrode and connected thereto. The first finger electrodes extend parallel to each other along a second direction and are spaced apart in a first direction between adjacent first and second bus electrodes. The ends of the first finger electrodes are spaced apart from the second bus electrodes. The second finger electrodes extend parallel to each other along a second direction and are spaced apart in a first direction between adjacent first and second bus electrodes. The ends of the first finger electrodes are spaced apart from the second bus electrodes. The first finger electrodes and second finger electrodes are alternately arranged in the first direction between adjacent first and second bus electrodes.

[0010] In some implementations, each first bus electrode and each second bus electrode are respectively connected to a plurality of pads spaced apart in a first direction.

[0011] In some implementations, the width of the pad in the second direction is greater than the width of the first bus electrode and the second bus electrode.

[0012] In some embodiments, the pads near the edge of the back contact solar cell are further away from the edge relative to the first bus electrode and / or the second bus electrode near the edge of the back contact solar cell, and the pads near the edge are electrically connected to the first bus electrode and / or the second bus electrode near the edge via connection electrodes.

[0013] Along the extension path of the insulating layer, all electrodes between the end pads and the edge of the back contact solar cell are covered by the insulating layer. When interconnecting the back contact solar cells with solder ribbons, a portion of the solder ribbon does not form a physical connection with the electrode beneath the insulating layer due to the obstruction of the insulating layer. This reduces the risk of the solder ribbon portion pulling the electrode at the edge of the back contact solar cell detached from the grid when adjacent back contact solar cells experience relative movement deviating from the first direction. Attached Figure Description

[0014] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the 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 utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 A rear view of the battery string of a back-contact solar cell module according to an exemplary embodiment of the present disclosure is shown.

[0016] Figure 2A rear view of a back-contact solar cell according to an example embodiment of the present disclosure is shown.

[0017] Figure 3 A diagram showing the back-contact solar cell arrangement of an example embodiment of the present disclosure is illustrated.

[0018] Figure 4 It shows Figure 1 A magnified view of position A in the image.

[0019] Figure 5 It shows Figure 1 A magnified view of position B in the image.

[0020] Figure 6 It shows Figure 1 A magnified view of position C in the image. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] The inventors of this disclosure have discovered that unavoidable relative movement between solar cells during the transfer of solar cell strings causes the solder ribbons connecting the solar cells in series to pull on the grid lines at the edge of the pads, leading to grid line detachment. Since the solder ribbons of back-contact solar cell strings are all located on the back side of the back-contact solar cells, inconsistent vertical vibration between adjacent back-contact solar cells further increases the risk of grid line detachment at the pad edges. Efforts have been made to improve the adhesion between the grid lines of the back-contact solar cells and the semiconductor silicon substrate to address this problem.

[0024] In view of the problems of the prior art, the inventors of this disclosure propose a new solution.

[0025] Figure 1 A battery string of a back-contact solar cell module according to an exemplary embodiment of this disclosure is shown. More specifically, Figure 1 A back-contact solar cell string comprising three adjacent back-contact solar cells 10 is shown. The three adjacent back-contact solar cells 10 have a rectangular plate shape, are substantially arranged on the same plane, are arranged along a first direction D1 and are connected to each other. Figure 2 It shows Figure 1 The example implementation shows a back view of a back-contact solar cell string. Figure 3 It shows Figure 1 The diagram shows a back view of the back-contact solar cell strings when they are not interconnected.

[0026] like Figure 1 As shown, the back-contact photovoltaic module includes a plurality of back-contact solar cells 10 arranged along a first direction D1 and a solder strip 20 extending along the first direction D1 and connecting these back-contact solar cells 10 in series.

[0027] like Figure 2 As shown, the back contact solar cell 10 includes a first bus electrode 11 and a second bus electrode 12 with different conductivity types. The first bus electrode 11 and the second bus electrode 12 are formed on the back side of the back contact solar cell 10, respectively collecting and transporting electrons and holes.

[0028] The first bus electrode 11 and the second bus electrode 12 extend parallel to each other in a first direction D1 and are alternately arranged in a second direction D2, wherein the first direction D1 and the second direction D2 are two mutually perpendicular directions. Specifically, as Figure 2 As shown, the first bus electrodes 11 extend parallel to each other along the first direction D1 and are spaced apart along the second direction D2. The second bus electrodes 12 extend parallel to each other along the first direction D1 and are spaced apart along the second direction D2. The first bus electrodes 11 and the second bus electrodes 12 are alternately arranged along the second direction D2 and are spaced apart from each other by a uniform or substantially uniform distance.

[0029] Please continue to refer to this. Figure 2 The back-contact solar cell 10 also includes a first finger electrode 13 with the same conductivity type as the first bus electrode 11 and a second finger electrode 14 with the same conductivity type as the second bus electrode 12. The first finger electrode 13 and the second finger electrode 14 are formed on the back side of the back-contact solar cell 10 and are connected to the first bus electrode 11 and the second bus electrode 12, respectively, to collect electrons and holes. The first finger electrode 13 extends parallel to each other along a second direction D2 between adjacent first bus electrodes 11 and second bus electrodes 12, and is spaced apart in a first direction D1, with the ends of the first finger electrode 13 spaced apart from the second bus electrode 12. The second finger electrode 14 extends parallel to each other along the second direction D2 between adjacent first bus electrodes 11 and second bus electrodes 12, and is spaced apart in the first direction D1, with the ends of the first finger electrode 13 spaced apart from the second bus electrode 12. The first finger electrode 13 and the second finger electrode 14 between adjacent first bus electrode 11 and second bus electrode 12 are alternately arranged in the first direction D1 and are spaced apart by a uniform distance.

[0030] The back side of the back contact solar cell also has multiple sets of pads spaced apart in the second direction D2, each set of pads having multiple pads 15 spaced apart in the first direction D1. Specifically, each first bus electrode 11 and each second bus electrode 12 is respectively connected to the multiple pads 15 spaced apart in the first direction D1. The width of the pads 15 in the second direction D2 is greater than the width of the first bus electrode 11 and the second bus electrode 12. More specifically, the pads 15 include a first pad 151 electrically connected to the first bus electrode 11 and a second pad 152 electrically connected to the second bus electrode 12.

[0031] In some examples, pad 15 is formed as part of the first bus electrode 11 and the second bus electrode 12.

[0032] In some examples, the pads 15 of a localized area of ​​the back contact solar cell 10 are allowed to be separated from the bus electrodes. For example, at the edge of the back contact solar cell 10, the pads 15 are physically separated from the first bus electrode 11 and / or the second bus electrode 12 near the edge of the solar cell. The pads 15 are further away from the edge near the first bus electrode 11 and / or the second bus electrode 12 relative to the first bus electrode 11 and / or the second bus electrode 12, and the pads 15 are electrically connected to the first bus electrode 11 and / or the second bus electrode 12 at that edge via the connecting electrode 16. The solder ribbon 20 is physically and electrically connected to the pads 15, separating the bus electrodes at the edge from the pads 15, thus reducing the risk of microcracks at the cell edge caused by soldering the solder ribbon 20 at the edge of the back contact cell. The current of the first bus electrode 11 and / or the second bus electrode 12 at the edge is transferred to the pads 15 and the solder ribbon 20 through the connecting electrode 16.

[0033] The back-contact solar cells 10 are arranged along a first direction D1. The first bus electrode 11 and the second bus electrode 12 both extend along the first direction D1, and the first bus electrode 11 and the second bus electrode 12 of adjacent back-contact solar cells are aligned. More specifically, the first pad 151 and the second pad 152 of adjacent back-contact solar cells are aligned. For example, the first pad 151 of the second back-contact solar cell 10b is aligned with the second pad 152 of the adjacent first back-contact solar cell 10a and the third back-contact solar cell 10c, and the second pad 152 of the second back-contact solar cell 10b is aligned with the first pad 151 of the adjacent first back-contact solar cell 10a and the third back-contact solar cell 10c.

[0034] Please refer to Figure 1The first pad 151 and the second pad 152 are respectively connected to the solder ribbon 20, and then to the second pad 152 and the first pad 151 of another back-contact solar cell 10 adjacent to the first back-contact solar cell 10. The solder ribbon 20 is configured to connect multiple back-contact solar cells in series. Figure 1 As shown, a battery string consisting of three back-contact solar cells 10 is used as an example.

[0035] Figure 1 The back-contact solar cell string shown includes a first back-contact solar cell 10a, a second back-contact solar cell 10b, and a third back-contact solar cell 10c, which are arranged sequentially in the first direction D1.

[0036] Taking the second back-contact solar cell 10b in the middle as an example, the solder ribbon 20 includes a first solder ribbon 21 and a second solder ribbon 22, both extending along the first direction D1. One side of the first solder ribbon 21 is electrically connected to the first pad 151 of the second back-contact solar cell 10b, and the other side is electrically connected to the second pad 152 of the first back-contact solar cell 10a. One side of the second solder ribbon 22 is electrically connected to the second pad 152 of the second back-contact solar cell 10b, and the other side is electrically connected to the first pad 151 of the third back-contact solar cell 10c, thereby connecting the first back-contact solar cell 10a, the second back-contact solar cell 10b, and the third back-contact solar cell in series.

[0037] More specifically, the first solder strip 21 is electrically connected to the first pad 151 of the second back contact solar cell 10b arranged along the first direction D1, extends along the first direction D1 to the adjacent first back contact solar cell 10a, and is electrically connected to the second pad 152 of the first back contact solar cell 10a, thereby connecting the second back contact solar cell 10b and the first back contact solar cell 10a in series. The second solder strip 22 is electrically connected to the second pad 152 of the second back contact solar cell 10b arranged along the first direction D1, extends along the first direction D1 to the adjacent third back contact solar cell 10c, and is electrically connected to the second pad 152 of the third back contact solar cell 10c.

[0038] Figure 4 It shows Figure 1 The image shows a magnified view of position A of the back-contact solar cell string. Please refer to the image. Figure 1The portions of the dissimilar finger electrodes near the bus electrode and solder ribbon 20 are partially covered by an insulating layer 30 to prevent short circuits caused by contact between the solder ribbon 20 and the finger electrodes, which have opposite conductivity types. For example, the end of the second finger electrode 14 near the first bus electrode 11 and the first pad 151 is covered by an insulating layer 30, and the end of the first finger electrode 13 near the second bus electrode 12 and the second pad 152 is also covered by an insulating layer 30. For solder ribbons 20 connected to pads 15 that are physically separated from the edge of the first bus electrode 11 and / or the second bus electrode 12, an insulating layer 30 is also used to cover the dissimilar electrode below. The insulating layer 30 can be an electrically insulating material with one or more of epoxy resin, silicone resin, polyurethane, or acrylic resin as its main components.

[0039] In some examples, the solder ribbons 20 connecting adjacent back-contact solar cells in series are respectively connected to the pads 15 closest to each other of the adjacent back-contact solar cells 10. A separator layer 40 is provided between the portion 23 of the solder ribbon 20 located between the pair of closest pads 15 and the pair of adjacent back-contact solar cells 10. The separator layer 40 extends continuously along a first direction D1 from the pads 15 to the adjacent edges of the pair of back-contact solar cells 10. The separator layer 40 may have the same material as the insulating layer 30.

[0040] Figure 5 It shows Figure 1 The illustrated example embodiment shows a partial enlarged view of the adjacent edge B positions of adjacent back-contact solar cells. More specifically, continuing with the example of the second back-contact solar cell 10b, the second back-contact solar cell 10b has a first edge e1 adjacent to the first back-contact solar cell 10a, and the first back-contact solar cell 10a has a second edge e2 adjacent to the second back-contact solar cell 10b. A first solder strip 21 crosses the first edge e1 and the second edge e2. A first pad 151 disposed on the back side of the second back-contact solar cell 10b includes a first end pad 151a closest to the first edge e1, and a second pad 152 disposed on the back side of the first back-contact solar cell 10a includes a second end pad 152a closest to the second edge e2. The back side of the second back-contact solar cell 10b has an isolation layer 40 extending from the first end pad 151a to the first edge e1, and the back side of the first back-contact solar cell 10a has an isolation layer 40 extending from the second end pad 152a to the second edge e2.

[0041] Figure 6 It shows Figure 1The illustrated example embodiment shows a partial enlarged view of the adjacent edge C positions of adjacent back-contact solar cells. The second back-contact solar cell 10b has a second edge e2 adjacent to the third back-contact solar cell 10c, and the third back-contact solar cell 10c has a first edge e1 adjacent to the second back-contact solar cell 10b. A second solder strip 22 spans the second edge e2 and the first edge e1. A second pad 152 disposed on the back side of the second back-contact solar cell 10b includes a second end pad 152a closest to the second edge e2, and a first pad 151 disposed on the back side of the third back-contact solar cell 10c includes a first end pad 151a closest to the first edge e1. The back side of the second back-contact solar cell 10b has an isolation layer 40 extending from the second end pad 152a to the second edge e2, and the back side of the third back-contact solar cell 10c has an isolation layer 40 extending from the first end pad 151a to the first edge e1.

[0042] Along the extension path of the isolation layer 40, all electrodes between the end pad 15 and the edge of the back contact solar cell are covered by the isolation layer 40. Examples include bus electrodes, and same- and opposite-shaped finger electrodes. When the back contact solar cells are interconnected using solder ribbons 20, no physical connection is formed between the portion 23 of the solder ribbon 20 and the electrode below the isolation layer 40 due to the obstruction of the isolation layer 40. This reduces the risk that the portion 23 of the solder ribbon 20 will pull the electrode at the edge of the back contact solar cell off the grid when adjacent back contact solar cells experience relative movement deviating from the first direction D1.

[0043] In an exemplary embodiment of this disclosure, the isolation layer 40 has its centerline along the center line of the pad 15 in the first direction D1 as its centerline, and its minimum width W in the second direction D2 is 1.5-2.5 mm. The center line of the pad 15 in the first direction D1 is a virtual line passing through the center of the pad 15 and parallel to the first direction D1. Using the center line of the pad 15 in the first direction D1 as a reference, the minimum distance W / 2 from both sides of the isolation layer 40 to the center line of the pad 15 in the first direction D1 is 0.75-1.25 mm. The isolation layer 40 has a certain width, which both prevents a portion 23 of the solder ribbon 20 from physically connecting to the gate line and reduces the alignment requirements of the solder ribbon 20.

[0044] Finally, it should be noted that the above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. Back contact solar cell module, characterized in that, The device includes multiple back-contact solar cells arranged along a first direction and solder strips extending along the first direction and interconnecting the back-contact solar cells. The back side of each back-contact solar cell has multiple sets of pads spaced apart along a second direction. Each set of pads has multiple pads spaced apart along the first direction. The first direction and the second direction are perpendicular to each other. The solder strips connecting adjacent back-contact solar cells in series are respectively connected to the pads closest to each other of the adjacent back-contact solar cells. The portion of the solder strip located between the pads closest to each other has an isolation layer between it and the pair of adjacent back-contact solar cells. The isolation layer extends continuously along the first direction from the pads closest to each other to the edges of the pair of back-contact solar cells adjacent to each other.

2. The back contact solar cell module according to claim 1, characterized in that, Along the extension path of the isolation layer, all electrodes between the closest pads of the adjacent back-contact solar cells and the edges of the pair of back-contact solar cells adjacent to each other are covered by the isolation layer.

3. The back contact solar cell module according to claim 1, wherein The isolation layer is centered on the center line of the pair of pads closest to each other along the first direction, and the minimum width of the isolation layer in the second direction is 1.5-2.5 mm.

4. The back contact solar cell module according to claim 1, wherein The back-contact solar cell includes a first bus electrode and a second bus electrode with different conductivity types. The first bus electrode and the second bus electrode are formed on the back side of the back-contact solar cell. The first bus electrode and the second bus electrode extend parallel to each other in the first direction and are alternately arranged in the second direction.

5. The back contact solar cell module according to claim 4, characterized in that, The back contact solar cell further includes a first finger electrode that has the same conductivity type as the first bus electrode and is connected thereto, and a second finger electrode that has the same conductivity type as the second bus electrode and is connected thereto. The first finger electrode extends parallel to each other along the second direction and is spaced apart in the first direction between adjacent first bus electrodes and second bus electrodes, with the ends of the first finger electrodes spaced apart from the second bus electrodes. The second finger electrode extends parallel to each other along the second direction and is spaced apart in the first direction between adjacent first and second bus electrodes, with the ends of the first finger electrodes spaced apart from the second bus electrodes. The first finger electrode and the second finger electrode adjacent to the first bus electrode and the second bus electrode are alternately arranged in the first direction.

6. The back contact solar cell module according to claim 4, wherein Each of the first bus electrode and each of the second bus electrodes is electrically connected to a plurality of pads spaced apart in the first direction.

7. The back contact solar cell module according to claim 4, wherein The width of the pad in the second direction is greater than the width of the first bus electrode and the second bus electrode.

8. The back contact solar cell module according to claim 4, wherein The pads near the edge of the back contact solar cell are further away from the edge than the first bus electrode and / or the second bus electrode near the edge of the back contact solar cell, and the pads near the edge are electrically connected to the first bus electrode and / or the second bus electrode near the edge via connecting electrodes.

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