Back contact photovoltaic module
By employing an alternating and spaced-apart solder strip design in the back contact solar cell module, physical isolation between electrodes is achieved by aligning the protrusions and recesses with the finger electrodes. This solves the problem of requiring insulating adhesive in the prior art, simplifies the process, reduces costs, and improves welding efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HEFEI GCL SYST INTEGRATION NEW ENERGY TECH CO LTD
- Filing Date
- 2025-06-27
- Publication Date
- 2026-07-03
AI Technical Summary
In existing technologies, insulating adhesive is required when connecting back-contact solar cell modules to the opposite electrode via solder strips, which increases the number of processes and costs.
Alternating and spaced first and second solder strips are used, with protrusions and recesses on the solder strips, which are alternately aligned with the finger electrodes of the back contact solar cell. Insulation between the electrodes is achieved through physical spatial isolation, eliminating the need for insulating adhesive.
The process was simplified, costs were reduced, the risk of microcracks at the battery edges was decreased, and welding efficiency was improved.
Smart Images
Figure CN224460430U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of photovoltaic technology, specifically to back-contact photovoltaic modules. 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 photovoltaic module.
[0003] In existing technologies, insulating adhesive is used to isolate the solder ribbon from adjacent opposite electrodes. Printing insulating adhesive on the back of the back contact solar cell increases the process and cost. Utility Model Content
[0004] This invention provides a back-contact photovoltaic module that can be insulated without the use of insulating adhesive.
[0005] The back-contact photovoltaic module includes a back-contact solar cell and solder strips extending along a first direction and connected to the back-contact solar cell. The solder strips include a first solder strip and a second solder strip that are alternately spaced apart from each other in a second direction. The first direction and the second direction are perpendicular. The first solder strip and the second solder strip each have alternating protrusions along their length and recesses that are recessed relative to the protrusions. The back-contact solar cell includes a first finger electrode and a second finger electrode extending along the second direction on the back side of the back-contact solar cell. The first finger electrode and the second finger electrode are alternately arranged in the first direction. The protrusions of the first solder strip are electrically connected to the first finger electrode, and the recesses of the first solder strip are aligned with the second finger electrode. The protrusions of the second solder strip are electrically connected to the second finger electrode, and the recesses of the second solder strip are aligned with the first finger electrode.
[0006] In some embodiments, the back-contact solar cell further includes a first bus electrode and a second bus electrode 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.
[0007] The first finger electrode and the second finger electrode are respectively connected to the first bus electrode and the second bus electrode. The first finger electrode extends parallel to each other along a second direction between adjacent first bus electrodes and second bus electrodes, and is arranged at intervals in a first direction. 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 between adjacent first bus electrodes and second bus electrodes, and are arranged at intervals in a first direction. The ends of the first finger electrodes are spaced apart from the second bus electrodes. The first finger electrodes and the second finger electrodes between adjacent first bus electrodes and second bus electrodes are alternately arranged in the first direction.
[0008] 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.
[0009] In some embodiments, the first finger electrode and the second finger electrode extend continuously from one end of the back contact solar cell to the other end along a second direction.
[0010] In some embodiments, the length of the recess in the first direction is greater than the width of the first and second finger electrodes, and less than the distance between adjacent first and second finger electrodes.
[0011] In some implementations, the recess is narrower than the protrusion in the radial direction.
[0012] In some embodiments, the cross-section of the solder strip is circular, the recess and the protrusion are concentric, and the cross-sectional diameter of the recess is smaller than the cross-sectional diameter of the protrusion.
[0013] Since the recessed portion of the first solder strip is aligned with the second finger electrode, and the recessed portion of the second solder strip is aligned with the first finger electrode, there is an isolation space between the first solder strip and the second solder strip and the opposite finger electrode. Through this physical space isolation, the insulating adhesive can be eliminated. 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 cell string of a back-contact photovoltaic module according to an example embodiment of the present disclosure is shown.
[0016] Figure 2 A back view of a back-contact solar cell of a back-contact photovoltaic module according to an example embodiment of the present disclosure is shown.
[0017] Figure 3 The arrangement of the back-contact solar cells of a back-contact photovoltaic module according to an example embodiment of the present disclosure is shown.
[0018] Figure 4 A schematic diagram of the solder strip of a back-contact photovoltaic module according to an example embodiment of the present disclosure is shown.
[0019] Figure 5The diagram illustrates a back-contact photovoltaic module with a solder strip and a back-contact solar cell connection structure according to an exemplary embodiment of the present disclosure.
[0020] Figure 6 The diagram illustrates a back-contact photovoltaic module with a solder strip connection structure to a back-contact solar cell, representing another exemplary embodiment of this disclosure. 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] Figure 1 A cell string of a back-contact photovoltaic 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 the arrangement of the back-contact solar cells in the back-contact solar cell string.
[0024] 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.
[0025] 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. Specifically, as shown... Figure 2 As shown, 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. For example, as Figure 2As 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 distance.
[0026] 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. Please continue to refer to Figure 2 A first finger electrode 13 and a second finger electrode 14 are formed on the back side of the back-contact solar cell 10, and are connected to a first bus electrode 11 and a second bus electrode 12, respectively, to collect electrons and holes. The first finger electrodes 13 extend parallel to each other along a second direction D2 between adjacent first bus electrodes 11 and second bus electrodes 12, and are spaced apart along a first direction D1, with the ends of the first finger electrodes 13 spaced apart from the second bus electrodes 12. The second finger electrodes 14 extend parallel to each other along the second direction D2 between adjacent first bus electrodes 11 and second bus electrodes 12, and are spaced apart along the first direction D1, with the ends of the first finger electrodes 13 spaced apart from the second bus electrodes 12. The first finger electrodes 13 and second finger electrodes 14 are alternately arranged along the first direction D1 between adjacent first bus electrodes 11 and second bus electrodes 12, and are spaced apart at a uniform distance.
[0027] Each first bus electrode 11 and each second bus electrode 12 are respectively connected to a plurality of pads 15 spaced apart in a 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, as Figure 2 As shown, the pad 15 includes 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.
[0028] In some examples, pad 15 may be formed as part of the first bus electrode 11 and the second bus electrode 12.
[0029] 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 electrode. For example, such as Figure 2As shown, at the edge of the back contact solar cell 10, the pad 15 is physically separated from the first bus electrode 11 and / or the second bus electrode 12 near the edge of the solar cell. The pad 15 is 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 pad 15 is electrically connected to the first bus electrode 11 and / or the second bus electrode 12 at the edge via the connecting electrode 16. The solder ribbon 20 is physically and electrically connected to the pad 15, separating the bus electrode at the edge from the pad 15, thus reducing the risk of microcracks at the edge of the cell 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 transmitted to the pad 15 and the solder ribbon 20 through the connecting electrode 16.
[0030] The back-contact solar cells 10 are arranged along a first direction D1, and the first bus electrode 11 and the second bus electrode 12 both extend along the first direction D1. The first bus electrode 11 and the second bus electrode 12 of adjacent back-contact solar cells are aligned. For more details, please refer to... Figure 3 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.
[0031] The 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. Figure 1The 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. Taking the middle second back-contact solar cell 10b 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 and alternately spaced apart in the second direction D2. 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 10c in series.
[0032] More specifically, the first solder ribbon 21 is physically and electrically connected to the first pads 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 physically and electrically connected to the second pads 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 ribbon 22 is physically and electrically connected to the second pads 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 physically and electrically connected to the second pads 152 of the third back contact solar cell 10c.
[0033] The solder ribbon 20 is electrically connected to the first finger electrode 13 and the second finger electrode 14 of the back contact solar cell 10. More specifically, the first solder ribbon 21 is physically and electrically connected to the first pad 151 of the back contact solar cell 10, the first pad 151 is electrically connected to the first bus electrode 11, the first bus electrode 11 is electrically connected to the first finger electrode 13, and thus the first solder ribbon 21 is indirectly electrically connected to the first bus electrode 11. The second solder ribbon 22 is physically and electrically connected to the second pad 152 of the back contact solar cell 10, the second pad 152 is electrically connected to the second bus electrode 12, the second bus electrode 12 is electrically connected to the second finger electrode 14, and thus the second solder ribbon 22 is indirectly electrically connected to the second bus electrode 12.
[0034] Figure 4 The structure of the solder strip in an exemplary embodiment of this disclosure is shown. Please refer to... Figure 4The solder strip 20 has alternating protrusions 23 and recesses 24 that are recessed relative to the protrusions 23 along its length. Specifically, the recesses 24 are smaller in width than the protrusions 23. For example, the solder strip 20 has a circular cross-section, the recesses 24 are concentric with the protrusions 23, and the cross-sectional diameter of the recesses 24 is smaller than the cross-sectional diameter of the protrusions 23.
[0035] Figure 5 The diagram illustrates a connection structure between the solder strip and a back-contact solar cell in an exemplary embodiment of this disclosure. Taking the second back-contact solar cell 10b as an example, as... Figure 5 As shown, the protrusion 23 of the first solder ribbon 21 is electrically connected to the first finger electrode 13, and the recess 24 of the first solder ribbon 21 is aligned with the second finger electrode 14. Similarly, the protrusion 23 of the second solder ribbon 22 is electrically connected to the second finger electrode 14, and the recess 24 of the second solder ribbon 22 is aligned with the first finger electrode 13. The protrusion 23 of the first solder ribbon 21 and the protrusion 23 of the second solder ribbon 22 are electrically connected to the second finger electrode 14, respectively collecting electrons and holes. Because the recess 24 of the first solder ribbon 21 is aligned with the second finger electrode 14, and the recess 24 of the second solder ribbon 22 is aligned with the first finger electrode 13, the first solder ribbon 21 and the second solder ribbon 22 are suspended relative to the opposite-shaped finger electrodes, forming an isolation space. This physical spatial isolation eliminates the need for insulating adhesive.
[0036] Figure 6 A connection structure between the solder strip and the back contact solar cell is shown in another exemplary embodiment of this disclosure. According to some exemplary embodiments of this disclosure, the back contact solar cell 10 may not have a first bus electrode 11 and a second bus electrode 12, and the back contact solar cell 10 may have a first finger electrode 13 and a second finger electrode 14. The first finger electrode 13 and the second finger electrode 14 may extend continuously along a second direction D2. The first finger electrode 13 and the second finger electrode 14 extend from one end of the back contact solar cell 10 to the other end. In these embodiments, as... Figure 6 As shown, the protrusion 23 of the first solder strip 21 is physically and electrically connected to the first finger electrode 13, the recess 24 of the first solder strip 21 is aligned with the second finger electrode 14, the protrusion 23 of the second solder strip 22 is physically and electrically connected to the second finger electrode 14, and the recess 24 of the second solder strip 22 is aligned with the first finger electrode 13.
[0037] In some embodiments, the width of the first finger electrode 13 and the second finger electrode 14 is W1, the spacing between adjacent first finger electrodes 13 and second finger electrodes 14 is W2, and the length W3 of the recess 24 in the first direction D1 satisfies W1 < W3 < W2. The length of the recess 24 in the first direction D1 is greater than the width of the finger electrode. When there is an alignment error in the solder strip, the length of the recess 24 is sufficient to cover the width of the finger electrode. The length of the recess 24 in the first direction D1 is less than the spacing between adjacent first finger electrodes 13 and second finger electrodes 14. For a back-contact solar cell having a bus electrode, the protrusion 23 has a sufficient density to keep a certain contact area between the solder strip and the bus electrode. For a back-contact solar cell without a bus electrode, the protrusion 23 can contact and connect with the finger electrodes of the same polarity.
[0038] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. Back contact photovoltaic module, characterized in that, The device includes a back-contact solar cell and solder strips extending along a first direction and connected to the back-contact solar cell. The solder strips include a first solder strip and a second solder strip that are alternately spaced apart from each other in a second direction, the first direction and the second direction being perpendicular. The first solder strip and the second solder strip each have alternating protrusions along their length and recesses relative to the protrusions. The back-contact solar cell includes a first finger electrode and a second finger electrode extending along the second direction on the back side of the back-contact solar cell. The first finger electrode and the second finger electrode are alternately arranged in the first direction. The protrusions of the first solder strip are electrically connected to the first finger electrode, the recesses of the first solder strip are aligned with the second finger electrode, the protrusions of the second solder strip are electrically connected to the second finger electrode, and the recesses of the second solder strip are aligned with the first finger electrode.
2. The back contact photovoltaic module of claim 1, wherein, The back-contact solar cell further includes a first bus electrode and a second bus electrode 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 the first direction and alternately arranged in the second direction. The first finger electrode and the second finger electrode are respectively connected to the first bus electrode and the second bus electrode. The first finger electrodes extend parallel to each other along the second direction between adjacent first and second bus electrodes and are spaced apart in the first direction, with the ends of the first finger electrodes spaced apart from the second bus electrodes. The second finger electrodes extend parallel to each other along the second direction between adjacent first and second bus electrodes and are spaced apart in the first direction, 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.
3. The back contact photovoltaic assembly of claim 1, 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.
4. The back contact photovoltaic assembly of claim 1, wherein, The first finger electrode and the second finger electrode extend continuously from one end of the back contact solar cell to the other end along the second direction.
5. The back contact photovoltaic assembly of claim 1, wherein, The length of the recess in the first direction is greater than the width of the first and second finger electrodes, and less than the distance between adjacent first and second finger electrodes.
6. The back contact photovoltaic assembly of claim 1, wherein, In the radial direction, the recessed portion is smaller in width than the protruding portion.
7. The back contact photovoltaic assembly of claim 6, wherein, The cross-section of the welding strip is circular, the recessed portion and the protrusion are concentric, and the cross-sectional diameter of the recessed portion is smaller than the cross-sectional diameter of the protrusion.