Photovoltaic module

Abstract

This application discloses a photovoltaic module, relating to the field of photovoltaic technology, including a solar cell, a plurality of solder joints located on a first side of the solar cell, an insulating portion and a conductor located on the first side, the insulating portion and the conductor being located on the side of the solder joints away from the solar cell; on the first side of the solar cell, the insulating portion is located at least on opposite sides of the solder joints along a first direction, the first direction being perpendicular to the extension direction of the main grid in the solar cell, and an insulating portion is provided between each solder joint arranged along the first direction; the conductor is electrically connected to each solder joint in a one-to-one correspondence, the edge of the conductor not exceeding the edge of the solder joint and located between the insulating portions adjacent to the solder joint; the conductor is used for welding with a solder strip, before welding, the highest point of the conductor is higher than the highest point of the insulating portion, and the center thickness of the conductor is greater than the outer thickness; after welding, the bottom surface and at least one side surface of the solder strip are in contact with the conductor. Thus, while avoiding unnecessary short-circuit problems, it also helps to improve the welding reliability between the solder strip and each solar cell.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and more specifically, to a photovoltaic module. Background Technology

[0002] In photovoltaic modules, back-contact solar cells are cells in which both the emitter and base contact electrodes are located on the back of the cell. The light-receiving surface of this cell is not blocked by any metal electrodes, which effectively increases the short-circuit current of the cell. At the same time, the back can accommodate wider metal grid lines to reduce series resistance and thus improve the fill factor.

[0003] Since both the emitter and base electrodes are located on the back of the battery, short circuits can easily occur between them during subsequent soldering. Therefore, avoiding unnecessary short circuits during soldering while improving the reliability of the electrical connection between the solder ribbon and the battery cell has become one of the urgent technical problems to be solved at present. Summary of the Invention

[0004] In view of this, this application provides a photovoltaic module that helps to avoid the problem of short circuits caused by placing the emitter and base on the same surface of the cell, and also helps to improve the reliability of the electrical connection between the solder ribbon and the cell.

[0005] In a first aspect, this application provides a photovoltaic module, including a solar cell and a plurality of solder joints located on a first side of the solar cell;

[0006] It also includes an insulating part and a conductor located on the first side, the insulating part and the conductor being located on the side of the solder joint away from the battery cell;

[0007] On the first side of the battery cell, the insulating portion is located at least on both sides of the solder joint along a first direction, the first direction being perpendicular to the extension direction of the main grid in the battery cell, and the insulating portion is provided between the solder joints arranged along the first direction;

[0008] The conductor is electrically connected to each of the solder joints in a one-to-one correspondence. The edge of the conductor does not extend beyond the edge of the solder joint and is located between the insulating portions adjacent to the solder joint. The conductor is used for welding with the solder strip. The conductor includes a first state before welding with the solder strip. In the first state, along a direction perpendicular to the plane where the battery cell is located, the distance between the surface of the conductor away from the solder joint and the solder joint is H01, and the distance between the surface of the insulating portion away from the solder joint and the solder joint is H02, where H01 > H02, and the center thickness of the conductor is greater than the outer thickness.

[0009] Optionally, the surface of the conductor away from the battery cell has an arc shape, and the orthographic projection of the conductor onto the battery cell is elliptical or circular.

[0010] Secondly, this application also provides another photovoltaic module, including a solar cell and a plurality of solder joints located on a first side of the solar cell;

[0011] It also includes an insulating part and a conductor located on the first side, the insulating part and the conductor being located on the side of the solder joint away from the battery cell;

[0012] On the first side of the battery cell, the insulating portion is located at least on both sides of the solder joint along a first direction, the first direction being perpendicular to the extension direction of the main grid in the battery cell, and the insulating portion is provided between the solder joints arranged along the first direction;

[0013] The conductor is electrically connected to the solder joint in a one-to-one correspondence;

[0014] It also includes a solder strip, through which two adjacent solar cells are electrically connected. The solder strip is located on the side of the conductor away from the solar cell and is soldered to the conductor. The first surface of the solder strip facing the solar cell and at least one side of the solder strip along a first direction are in contact with the conductor.

[0015] Optionally, along the first direction, the width of the solder strip is D1, and the maximum width of the conductor welded to the solder strip is D2, wherein D1 ≤ D2.

[0016] Optionally, the conductor is in contact with both sides of the solder strip along the first direction, and the center thickness of the conductor is less than the thickness of the opposite edges of the conductor along the first direction.

[0017] Optionally, along the first direction, the width of the conductor is 1000μm to 1300μm; the edge of the solder strip projected onto the plane of the battery cell includes a first edge, and the edge of the corresponding conductor projected onto the plane of the battery cell includes a second edge; along the first direction, the first edge and the second edge are located on the same side of the solder strip, and the distance between the first edge and the second edge is 220μm to 350μm.

[0018] Optionally, the maximum height of the conductor is 100μm to 300μm along a direction perpendicular to the plane of the battery cell, and the minimum height of the conductor between the solder strip and the solder joint is 50μm to 65μm.

[0019] Optionally, the conductor contacts a first side of the solder strip along the first direction, but does not contact a second side of the solder strip along the first direction, wherein the first side and the second side are opposite to each other.

[0020] Optionally, along the first direction, the width of the conductor is 1300μm to 1500μm; the edge of the solder strip that contacts the conductor in the orthographic projection of the plane where the battery cell is located is the third edge, and the edge of the conductor that does not contact the solder strip in the orthographic projection of the plane where the battery cell is located is the fourth edge; along the first direction, the distance between the third edge and the fourth edge is 450μm to 550μm.

[0021] Optionally, the maximum height of the conductor is 130μm to 150μm along a direction perpendicular to the plane of the battery cell, and the minimum height of the conductor between the solder strip and the solder joint is 80μm to 95μm.

[0022] Optionally, along the first direction, the width of the solder strip is D1, and the distance between the center of the solder strip and the center of the conductor is D0, wherein D0 / D1≤1 / 4.

[0023] Compared with existing technologies, the photovoltaic module provided in this application achieves at least the following beneficial effects:

[0024] The first photovoltaic module structure provided in this application corresponds to the structure before the solder ribbon is welded to the solar cell; the second photovoltaic module structure corresponds to the structure after the solder ribbon is welded to the solar cell. This application introduces insulating portions on both sides of the solder joints of the solar cell. All solder joints arranged along the first direction are isolated by these insulating portions to avoid the potential short circuit problem when the emitter and base of the solar cell are both located on the back side. In addition to the insulating portions, this application also introduces a conductor, which is located between the insulating portions adjacent to the solder joints and does not extend beyond the edge of the solder joints. Before the solder ribbon is welded to the conductor, the conductor is in a first state, in which the center thickness of the conductor is greater than the outer thickness, and the highest point of the conductor is higher than the highest point of the insulating portion. Since the conductor is electrically connected to the solder joint, when the highest point of the conductor is set higher than the highest point of the insulation part, the conductor protrudes from the insulation part before the solder strip is welded to the conductor. Therefore, the solder strip can easily contact the conductor before welding and thus achieve welding with the conductor. This effectively reduces the difficulty of electrical connection between the solder strip and the solder joint, and also helps to improve the reliability of electrical connection between the solder strip and the solder joint, thereby improving the reliability of photovoltaic modules.

[0025] Of course, any product implementing this application need not specifically need to achieve all of the technical effects described above at the same time.

[0026] Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.

[0028] Figure 1 The image shown is a top view of a photovoltaic module provided in an embodiment of this application, corresponding to a structure in which solder strips have not yet been introduced into the photovoltaic module;

[0029] Figure 2 The image shown is an enlarged schematic diagram of a single battery cell.

[0030] Figure 3 As shown Figure 2 A cross-sectional view of a solar cell along the AA direction;

[0031] Figure 4 The image shown is another top view of the photovoltaic module provided in the embodiment of this application;

[0032] Figure 5 As shown Figure 4 A diagram showing the relative positions of the solar cells and solder joints;

[0033] Figure 6 As shown Figure 5 A cross-sectional view of a solar cell in the BB direction;

[0034] Figure 7 As shown Figure 6 A top-view diagram showing the relationship between the solder strip, conductor, and solder joint;

[0035] Figure 8 The image shown is a cross-sectional view of the battery cell in another embodiment provided in this application;

[0036] Figure 9 As shown Figure 8 A top-view diagram showing the relationship between the solder strip, conductor, and solder joint. Detailed Implementation

[0037] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0038] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0039] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0040] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0041] Various modifications and variations can be made to this application without departing from its spirit or scope, which will be apparent to those skilled in the art. Therefore, this application is intended to cover modifications and variations falling within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the embodiments provided in this application can be combined with each other without contradiction.

[0042] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0043] Figure 1 The image shown is a top view of a photovoltaic module 100 provided in an embodiment of this application, corresponding to a structure in which solder strips have not yet been introduced into the photovoltaic module. Figure 2 As shown Figure 1 An enlarged schematic diagram of a single solar cell 10 shows the film layer relationship between the solder joint 20, the conductor 50, and the insulating part 40. Figure 3 As shown Figure 2 A cross-sectional view of the solar cell 10 along the AA direction. It should be noted that... Figure 1 Only some of the solar cells 10 in the photovoltaic module are shown; not all of the solar cells 10 are shown, nor is the number of solar cells 10 included in the photovoltaic module limited. Figure 1 and Figure 2 Only the main grid 30 on the cell 10 is shown in the image. Optionally, in some other embodiments, the cell 10 may also include a sub-grid.

[0044] Please refer to Figures 1 to 3 This application provides a photovoltaic module 100, including a cell 10 and a plurality of solder joints 20 located on the first side of the cell 10; optionally, the solder joints 20 may be part of the main grid 30 and manufactured simultaneously with the main grid 30, or they may be a structure independent of the main grid 30 but electrically connected to the main grid 30.

[0045] The photovoltaic module 100 also includes an insulating portion 40 and a conductor 50 located on the first side. The insulating portion 40 and the conductor 50 are located on the side of the solder joint 20 away from the cell 10. On the first side of the cell 10 (which can be regarded as the back side of the cell 10), the insulating portion 40 is located at least on both sides of the solder joint 20 along the first direction F1. The first direction F1 is perpendicular to the extension direction of the main grid 30 in the cell 10. The insulating portion 40 is provided between the solder joints 20 arranged along the first direction F1. The insulating portion 40 has a certain height to isolate adjacent solder joints 20 along the first direction F1 and prevent short circuits between different solder joints 20.

[0046] The conductor 50 is electrically connected to the solder joint 20 in a one-to-one correspondence. The edge of the conductor 50 does not extend beyond the edge of the solder joint 20 and is located between the insulating portions 40 adjacent to the solder joint 20. The conductor 50 is used for welding with the solder strip. The conductor 50 includes a first state before welding with the solder strip. In the first state, along the direction perpendicular to the plane where the battery cell 10 is located, the distance between the surface of the conductor 50 away from the solder joint 20 and the solder joint 20 is H01, and the distance between the surface of the insulating portion 40 away from the solder joint 20 and the solder joint 20 is H02. Wherein, H01 > H02, and the center thickness of the conductor 50 is greater than the outer thickness.

[0047] The photovoltaic module structure addressed in this embodiment is the structure before the solder ribbon is welded to the conductor 50. When the cells in the photovoltaic module are back-contact cells, the emitter and base of the cell 10 are both located on the back side of the cell 10. This application introduces insulating portions 40 on both sides of the solder joint 20 on the back side of the cell 10. The solder joints 20 arranged along the first direction F1 are all isolated by the insulating portions 40, thereby avoiding the problem of short circuit that may occur when the emitter and base of the cell are both located on the back side. When the insulating portions 40 are introduced on both sides of the solder joint 20, since the solder joint 20 needs to be electrically connected to the solder ribbon, the presence of the insulating portions 40 will affect the welding between the solder ribbon and the solder joint 20, which may lead to unreliable electrical connection between the solder ribbon and the solder joint 20. Therefore, in addition to the insulating portions 40, this application also introduces a conductor 50, which is located between the insulating portions 40 adjacent to the solder joint 20 and does not extend beyond the edge of the solder joint 20. Before welding the solder strip to the conductor 50, the conductor 50 is in its first state. In this state, the center thickness of the conductor 50 is greater than its outer thickness, and the distance between the surface of the conductor 50 away from the solder joint 20 and the solder joint 20 is H01, which is greater than the distance between the surface of the insulating part 40 away from the solder joint 20 and the solder joint 20 is H02. In other words, the highest point of the conductor 50 is higher than the highest point of the insulating part 40. Since the conductor 50 is electrically connected to the solder joint 20, when the highest point of the conductor 50 is set higher than the highest point of the insulating part 40, the conductor 50 protrudes from the insulating part 40 before welding the solder strip. Therefore, the solder strip can more easily contact the conductor 50 before welding, thus achieving welding. This effectively reduces the difficulty of electrical connection between the solder strip and the solder joint 20, and also helps improve the reliability of the electrical connection between the solder strip and the solder joint 20, thereby improving the reliability of the photovoltaic module.

[0048] Please continue to refer to this. Figure 2 and Figure 3 In one optional embodiment of the present invention, the surface shape of the conductor 50 away from the battery cell 10 is arc-shaped, and the orthographic projection of the conductor 50 onto the battery cell 10 is elliptical or circular.

[0049] Optionally, the conductor 50 provided in this application can be a conductive material such as solder paste. Before soldering the solder ribbon to the solder joint 20, a solder paste printing process is performed at the corresponding positions of each solder joint 20. The height of the printed solder paste is higher than the height of the insulating adhesive, thereby facilitating the soldering of the solder ribbon and the solder paste in subsequent processes. Since the solder paste is composed of spherical solder powder and solvent, the printed solder paste will collapse outwards, forming a state that is high in the middle and low around the edges. That is, it forms an arc-shaped structure away from the surface of the battery cell 10. At this time, the part of the conductor 50 that contacts the solder joint 20 has a circular or elliptical structure and does not exceed the range defined by the solder joint 20. When the conductor 50 is solder paste, the maximum height of the conductor 50 mentioned in this embodiment, which is greater than the height of the insulating part 40, refers to the maximum height of the printed and collapsed solder paste being greater than the height of the insulating part 40. That is, the center height of the solder paste is greater than the height of the insulating part 40. Of course, in addition to solder paste, the conductor 50 provided in this application can also be a conductive material such as conductive silver paste. This invention does not specifically limit this.

[0050] Optionally, the insulating part 40 provided in this application can be a material with insulating properties, such as insulating adhesive, polypropylene, polyvinyl chloride, polyimide, polyamide, etc. These materials have good insulation properties, high temperature resistance and chemical corrosion resistance, which can effectively isolate the solder joint 20 of the battery, avoid short circuit between the base and emitter of the battery, and help ensure the safety and stability of the battery.

[0051] Figure 4 The image shown is another top view of the photovoltaic module provided in this application embodiment, corresponding to the structure in which solder strips 60 are introduced into the photovoltaic module. Figure 5 As shown Figure 4 A diagram showing the relative positions of the solar cell 10 and the solder joint 20. Figure 6 As shown Figure 5 A cross-sectional view of the solar cell 10 along the BB direction shows the film layer relationship between the solder joint 20, the conductor 50, and the insulating part 40. Figure 7 As shown Figure 6 A top view of the relationship between the solder strip 60, the conductor 50, and the solder joint 20.

[0052] Please refer to Figures 4 to 7 This application also provides another photovoltaic module 101, including a cell 10 and a plurality of solder joints 20 located on the first side of the cell 10; optionally, the solder joints 20 may be part of the main grid 30 and manufactured at the same time as the main grid 30, or they may be a structure independent of the main grid 30 and electrically connected to the main grid 30.

[0053] The photovoltaic module also includes an insulating portion 40 and a conductor 50 located on the first side. The insulating portion 40 and the conductor 50 are located on the side of the solder joint 20 away from the cell 10. On the first side of the cell 10 (which can be regarded as the back side of the cell 10), the insulating portion 40 is located at least on both sides of the solder joint 20 along the first direction F1. The first direction F1 is perpendicular to the extension direction of the main grid 30 in the cell 10. The insulating portion 40 is provided between the solder joints 20 arranged along the first direction F1. The insulating portion 40 has a certain height to isolate adjacent solder joints 20 along the first direction F1 and prevent short circuits between different solder joints 20.

[0054] The conductor 50 is electrically connected to the solder joint 20 in a one-to-one correspondence; the photovoltaic module 101 in this embodiment also includes a solder ribbon 60, and two adjacent cells 10 are electrically connected through the solder ribbon 60. The solder ribbon 60 is located on the side of the conductor 50 away from the cell 10 and is soldered to the conductor 50. The first surface of the solder ribbon 60 facing the cell 10 and at least one side of the solder ribbon 60 along the first direction F1 are in contact with the conductor 50.

[0055] This embodiment illustrates the structure of a photovoltaic module after solder ribbon 60 is welded to solder joint 20 via conductor 50. After solder ribbon 60 is electrically connected to solder joint 20 via conductor 50, it forms an electrical connection with the corresponding solar cell 10. Thus, different solar cells 10 welded by the same solder ribbon 60 are electrically connected. Therefore, the reliability of the connection between solder ribbon 60 and solder joint 20 directly affects the reliability of the photovoltaic module. When insulation portions 40 are introduced on both sides of solder joint 20 to avoid unnecessary short circuits, the introduction of insulation portions 40 may cause some interference to the connection between solder ribbon 60 and solder joint 20, potentially affecting the reliability of the connection. Therefore, this application introduces conductor 50 on the side of solder joint 20 away from solar cell 10. The edge of the orthographic projection of conductor 50 onto the plane of solar cell 10 does not exceed the edge of the orthographic projection of solder joint 20 onto the plane of solar cell 10, and before welding, the top of conductor 50 protrudes beyond insulation portion 40. When the solder ribbon 60 is positioned on the side of the conductor 50 and the insulating part 40 away from the battery cell 10, the solder ribbon 60 will first come into contact with the conductor 50. When welding is then performed, for example, infrared welding can be used. After the conductor 50 melts, it is fixed to the solder ribbon 60 and forms an electrical connection. Compared with the method of directly connecting the solder ribbon 60 to the solder point 20, the method of introducing the conductor 50 is beneficial to reducing the electrical connection process between the solder ribbon 60 and the solder point 20, and at the same time, it is beneficial to improve the welding reliability between the solder ribbon 60 and the conductor 50, thereby improving the electrical connection reliability between the solder ribbon 60 and the solder point 20.

[0056] When the solder strip 60 is soldered to the conductor 50, at least one side of the solder strip 60 along the first direction F1 presents as shown in the figure. Figure 6In the state shown, in addition to the surface of the solder ribbon 60 facing the cell 10 contacting and connecting with the conductor 50, at least one side of the solder ribbon 60 along the first direction F1 also contacts and connects with the conductor 50. The height of the conductor 50 that contacts the side of the solder ribbon 60 is higher than the height of the conductor 50 that contacts the bottom of the solder ribbon 60. This helps to increase the contact area between the solder ribbon 60 and the conductor 50, thereby improving the reliability of the electrical connection between the solder ribbon 60 and the conductor 50 and between the solder ribbon 60 and the solder joint 20, and further improving the overall reliability of the photovoltaic module.

[0057] Please refer to Figure 6 In one optional embodiment of the present invention, along the first direction F1, the width of the solder strip 60 is D1, and the maximum width of the conductor 50 welded to the solder strip 60 is D2, wherein D1≤D2.

[0058] In this embodiment, the maximum width of the conductor 50 welded to the solder ribbon 60 refers to the maximum width of the conductor 50 along the first direction F1 after the solder ribbon 60 and the conductor 50 are welded. This helps to ensure that there are enough conductors 50 in contact with the solder ribbon 60 after the conductor 50 and the solder ribbon 60 are welded, thereby increasing the contact area between the conductor 50 and the solder ribbon 60 and ensuring the reliability of the electrical connection between the solder ribbon 60 and the conductor 50.

[0059] Figure 8 As shown Figure 5 Another BB-direction cross-sectional view of the battery cell 10. In an optional embodiment of the present invention, the conductor 50 is in contact with both sides of the solder strip 60 along the first direction F1, and the center thickness of the conductor 50 is less than the thickness of the opposite edges of the conductor 50 along the first direction F1.

[0060] Specifically, this embodiment illustrates a welding scheme in which the solder strip 60 is in contact with the conductor 50 on both sides along the first direction F1. Optionally, the solder strip 60 is located directly above the conductor 50. When the conductor 50 is melted using infrared welding to weld with the solder strip 60, the molten conductor 50 flows to both sides of the solder strip 60 along the first direction F1 under the pressure of the solder strip 60. Thus, the surface of the solder strip 60 facing the solder point 20 and the two sides of the solder strip 60 along the first direction F1 are in contact with the conductor 50. The upper surface of the conductor 50 is equivalent to forming a concave structure, and the inner wall of the concave structure is in contact with the solder strip 60. This is more conducive to increasing the contact area between the solder strip 60 and the conductor 50, thus improving the welding reliability between the solder strip 60 and the conductor 50, and further improving the overall reliability of the photovoltaic module.

[0061] Figure 9 As shown Figure 8A top view diagram showing the relationship between the solder strip 60, conductor 50, and solder joint 20. Please refer to the diagram. Figure 8 and Figure 9 In an optional embodiment of the present invention, along the first direction F1, the width S1 of the conductor 50 is 1000μm to 1300μm; the edge of the orthographic projection of the solder ribbon 60 onto the plane where the battery cell 10 is located includes a first edge B1, and the corresponding edge of the orthographic projection of the conductor 50 onto the plane where the battery cell 10 is located includes a second edge B2. Along the first direction F1, the first edge B1 and the second edge B2 are located on the same side of the solder ribbon 60, and the distance S2 between the first edge B1 and the second edge B2 is 220μm to 350μm.

[0062] When the solder ribbon 60 is welded to the conductor 50, and the bottom surface of the solder ribbon 60 and its two opposite sides along the first direction F1 are in contact with the conductor 50 to form an electrical connection, it is equivalent to the molten conductor 50 being squeezed by the solder ribbon 60 and spreading along the first direction F1 to both sides of the solder ribbon 60 during the welding process. At this time, the width of the conductor 50 along the first direction F1 can be regarded as the maximum width of the conductor 50 in the first direction F1. If the maximum width of the conductor 50 along the first direction F1 is less than 1000μm, the width of the conductor 50 is small, which may result in a small contact area between the conductor 50 and the solder ribbon 60, affecting the reliability of the electrical connection between the two. When the width of the conductor 50 along the first direction F1 is set to 1000μm to 1300μm, it is beneficial to ensure that the conductor 50 can extend to the opposite sides of the solder ribbon 60 along the first direction F1 during the welding process, thereby helping to ensure the reliability of the electrical connection between the two. Optionally, the width S1 of the conductor 50 can be any value within the range of 1000μm to 1300μm, such as 1050μm to 1250μm, 1100μm to 1200μm, 1080μm to 1280μm, etc. Alternatively, the width S1 of the conductor 50 can be any value within the range of 1000μm to 1300μm, and the width of the conductor 50 can also be selected as 1000μm, 1050μm, 1100μm, 1150μm, 1200μm, 1250μm, or 1300μm.

[0063] Continue to refer to Figure 9The distance between the first edge B1 of the solder ribbon 60 and the second edge B2 of the battery cell 10 along the first direction F1 can be considered as the maximum distance between the first edge B1 and the second edge B2. When this maximum distance is set to 220μm to 350μm, it can be considered that the conductor 50 extends 220μm to 350μm beyond the second edge of the solder ribbon 60 in the first direction F1. This helps to ensure the contact area between the solder ribbon 60 and the conductor 50, thereby improving the reliability of the electrical connection between the solder ribbon 60 and the conductor 50. Optionally, the distance between the first edge B1 and the second edge B2 can be set to any range between 220μm and 350μm, such as 230μm to 340μm, 250μm to 320μm, 280μm to 330μm, etc. Optionally, the distance between the first edge B1 and the second edge B2 can be set to any value between 220μm and 350μm, such as 240μm, 260μm, 280μm, 300μm, 320μm, 340μm, etc.

[0064] Continue to refer to Figure 8 In an optional embodiment of the present invention, along the direction perpendicular to the plane where the battery cell 10 is located, the maximum height H1 of the conductor 50 is 100μm to 300μm, and the minimum height H2 of the conductor 50 between the solder strip 60 and the solder point 20 is 50μm to 65μm.

[0065] In this embodiment, after the solder ribbon 60 is soldered to the conductor 50, the bottom surface of the solder ribbon 60 and the two opposite sides along the first direction F1 are in contact with the conductor 50. At this time, the height of the conductor 50 in contact with the side surface of the solder ribbon 60 is greater than the height of the conductor 50 in contact with the bottom surface of the solder ribbon 60. In this embodiment, the maximum height of the conductor 50 along the direction perpendicular to the plane of the battery cell 10 refers to the maximum thickness of the conductor 50 in contact with the side surface of the solder ribbon 60. When the maximum thickness of the conductor 50 is too small, for example, less than 100 μm, the contact area between the conductor 50 and the side surface of the solder ribbon 60 will be reduced, potentially affecting the reliability of the electrical connection. Therefore, this application sets the maximum height of the conductor 50 to 100 μm to 300 μm, which helps ensure sufficient contact area between the conductor 50 and the side surface of the solder ribbon 60, thereby improving the reliability of the electrical connection and the reliability of the fixation. Along the direction perpendicular to the plane where the battery cell 10 is located, the maximum height of the conductor 50 can be selected as any value in any range between 100μm and 300μm. For example, it can also be 200μm to 230μm, 150μm to 250μm, 180μm to 280μm, 120μm to 220μm, etc. Specifically, it can be 110μm, 130μm, 160μm, 180μm, 220μm, 260μm, 280μm, etc.

[0066] In this embodiment, the minimum height of the conductor 50 between the solder ribbon 60 and the solder joint 20 refers to the minimum thickness of the conductor 50 between the solder ribbon 60 and the solder joint 20. When the solder ribbon 60 and the conductor 50 are soldered, the conductor 50 melts and the solder ribbon 60 presses the conductor 50 downward. The larger the contact area between the bottom surface of the solder ribbon 60 and the conductor 50, the more obvious the pressing effect of the solder ribbon 60 on the conductor 50, and the smaller the thickness of the conductor 50 between the solder ribbon 60 and the solder joint 20 will be. When the solder ribbon 60 is directly above the conductor 50, and after welding, the conductor 50 simultaneously contacts the bottom surface of the solder ribbon 60 and the two opposite sides along the first direction F1, since the volume of the conductor 50 is fixed, when a portion of the conductor 50 extends to the two sides of the solder ribbon 60, the volume of the conductor 50 between the solder ribbon 60 and the solder joint 20 will decrease, and the thickness of this portion of the conductor 50 will also decrease. In this embodiment, the thickness is controlled to be 50μm to 65μm, so that a sufficient amount of conductor 50 can extend to the sides of the solder ribbon 60 and weld to the sides of the solder ribbon 60, thereby improving the reliability of the electrical connection and the fixing reliability between the solder ribbon 60 and the conductor 50. Optionally, the thickness of the conductor 50 between the solder ribbon 60 and the solder joint 20 can be selected from any range between 50μm and 65μm, such as 51μm to 60μm, 52μm to 62μm, 55μm to 63μm, etc. Optionally, the thickness of the conductor 50 between the solder strip 60 and the solder joint 20 can be any value between 50μm and 65μm, such as 52μm, 54μm, 56μm, 58μm, 60μm, 62μm, 64μm, etc.

[0067] The above embodiment illustrates a scheme where the solder ribbon 60 is located directly above the conductor 50, and after soldering, both sides of the conductor 50 and the solder ribbon 60 are in contact along the first direction F1. In actual manufacturing processes, the position of the solder ribbon 60 may deviate slightly; for example, it may not be directly above the conductor 50, but slightly to the left or right. For example, please refer to... Figure 6 and Figure 7 In an optional embodiment of the present invention, the conductor 50 contacts the first side M1 of the solder strip 60 along the first direction F1, but does not contact the second side M2 ​​of the solder strip 60 along the first direction F1, with the first side M1 and the second side M2 ​​opposite to each other.

[0068] It should be noted that, Figure 6 and Figure 7 The illustrated embodiment shows a scheme in which the solder strip 60 is offset to the right relative to the center of the conductor 50. In some other embodiments of the present invention, the solder strip 60 may also be offset to the left relative to the center of the conductor 50. The present invention does not specifically limit this.

[0069] When the solder strip 60 deviates from the center of the conductor 50 along the first direction F1, for example as Figure 6 and 7 When deviating to the right as shown, during infrared welding, the conductor 50 melts, and the solder strip 60 presses downwards against the molten conductor 50, causing part of the conductor 50 to extend upwards from the left side of the solder strip 60 (shown as the first side M1 in the figure) to contact and weld with the left side of the solder strip 60. However, because the solder strip 60 is deviated to the right, and due to the obstruction of the bottom surface of the solder strip 60, the conductor 50 cannot extend further to its right side (shown as the second side M2 ​​in the figure), thus presenting the following appearance. Figure 6 The state shown is as follows. At this time, in addition to the bottom surface of the solder strip 60, another side of the solder strip 60 is in contact with and electrically connected to the conductor 50. The conductor 50 can also play a certain role in fixing the solder strip 60, and at the same time, it can also ensure a reliable electrical connection between the conductor 50 and the solder strip 60.

[0070] Please refer to Figure 7 When the conductor 50 contacts and welds the bottom surface and one side surface of the solder strip 60, in an optional embodiment of the present invention, the width of the conductor 50 along the first direction F1 is 1300μm to 1500μm. At this time, the width of the conductor 50 refers to the maximum width along the first direction F1 after the solder strip 60 and the conductor 50 are welded and fixed. During the infrared welding process, the conductor 50 melts, and the solder strip 60 squeezes the molten conductor 50, causing the conductor 50 to diffuse to a certain extent along the first direction F1. At the same time, a portion of the conductor 50 extends upward from the first side surface M1 of the solder strip 60 under the pressure. When the width of the conductor 50 is set to 1300μm to 1500μm, the contact area between the bottom surface of the solder strip 60 and the conductor 50 can be increased to a certain extent. Thus, when only the bottom surface and the first side surface M1 of the solder strip 60 are in contact with the conductor 50, the contact area between the conductor 50 and the solder strip 60 can be maximized, thereby improving the electrical connection reliability and fixing reliability of the two. Optionally, in this embodiment, the width of the conductor 50 can be any range between 1300μm and 1500μm, such as 1310μm to 1490μm, 1350μm to 1450μm, 1400μm to 1480μm, etc.; alternatively, in this embodiment, the width of the conductor 50 can be any value between 1300μm and 1500μm, such as 1350μm, 1400μm, 1450μm, etc., and the present invention does not impose a specific limitation on it.

[0071] Please continue to refer to this. Figure 7The edge of the solder ribbon 60 that contacts the conductor 50 in the orthographic projection of the plane containing the solar cell 10 is designated as the third edge B3. The edge of the conductor 50 that does not contact the solder ribbon 60 in the orthographic projection of the plane containing the solar cell 10 is designated as the fourth edge B4. The distance S3 between the third edge B3 and the fourth edge B4 along the first direction F1 is 450μm to 550μm. This distance can be understood as the maximum distance between the third edge B3 and the fourth edge B4. Setting this maximum distance to 450μm to 550μm can be considered as the conductor 50 extending 450μm to 550μm beyond the third edge of the solder ribbon 60 in the first direction F1. This helps to ensure the contact area between the side of the solder ribbon 60 and the conductor 50, thereby improving the reliability of the electrical connection between the solder ribbon 60 and the conductor 50. Optionally, the distance between the third edge B3 and the fourth edge B4 can be set to any range between 450μm and 550μm, such as 160μm to 540μm. Alternatively, the distance between the third edge B3 and the fourth edge B4 can be set to any value between 450μm and 550μm, such as 460μm, 480μm, 500μm, 520μm, 540μm, etc. The present invention does not impose specific limitations on this.

[0072] Continue to refer to Figure 6 and Figure 7 When the conductor 50 contacts and welds with the bottom surface and one side surface of the solder strip 60, in an optional embodiment of the present invention, the maximum height H3 of the conductor 50 is 130μm to 150μm along the direction perpendicular to the plane where the battery cell 10 is located, and the minimum height H4 of the conductor 50 between the solder strip 60 and the solder point 20 is 80μm to 95μm.

[0073] Specifically, when the conductor 50 is in contact with only the bottom surface and one side surface of the solder strip 60, the height of the conductor 50 in contact with the side surface of the solder strip 60 will be greater than the height of the conductor 50 in contact with the bottom surface of the solder strip 60. In this embodiment, the maximum height of the conductor 50 along the direction perpendicular to the plane of the battery cell 10 refers to the height of the conductor 50 in contact with the side surface of the solder strip 60. Figure 6This is reflected in the maximum thickness of the conductor 50 that contacts the first side surface (M1). When the conductor 50 only contacts the bottom surface and one side surface of the solder strip 60, if the maximum thickness of the conductor 50 is too small, for example, less than 130 μm, the contact area between the conductor 50 and the side surface of the solder strip 60 will be reduced, which may affect the reliability of the electrical connection between the two. Therefore, in this embodiment, the maximum height of the conductor 50 is set to 130 μm to 150 μm, which helps to ensure that the conductor 50 has a sufficient area to contact the side surface of the solder strip 60, thereby improving the reliability of the electrical connection and the fixation. Optionally, along the direction perpendicular to the plane where the battery cell 10 is located, the maximum height of the conductor 50 can be selected to be any range between 130 μm and 150 μm, such as 132 μm to 148 μm, 135 μm to 145 μm, 138 μm to 142 μm, etc. Optionally, the maximum height of the conductor 50 along the direction perpendicular to the plane where the battery cell 10 is located can be any value in any range between 130μm and 150μm, specifically 135μm, 140μm, 145μm, etc.

[0074] When the conductor 50 is in contact with only the bottom surface and one side surface of the solder ribbon 60, the conductor 50 melts when the solder ribbon 60 is soldered to the conductor 50. The solder ribbon 60 shifts to the right relative to the center of the conductor 50 and squeezes the conductor 50 downward. The larger the contact area between the bottom surface of the solder ribbon 60 and the conductor 50, the more obvious the squeezing effect of the solder ribbon 60 on the conductor 50, and the smaller the thickness of the conductor 50 between the solder ribbon 60 and the solder joint 20 will be. When the solder strip 60 is offset to the right by a certain distance from the center of the conductor 50, after welding, the conductor 50 simultaneously contacts the bottom surface and one side surface of the solder strip 60. In this case, the compression of the conductor 50 by the solder strip 60 is slightly less, and part of the conductor 50 extends to one side of the solder strip 60. The volume of the conductor 50 between the solder strip 60 and the solder point 20 is reduced to a certain extent, and the thickness of this part of the conductor 50 will also be slightly reduced. In this embodiment, the thickness is controlled to be 80μm to 95μm, so that a sufficient amount of conductor 50 can extend to one side of the solder strip 60 and weld to the side of the solder strip 60, thereby improving the reliability of the electrical connection and the fixing reliability between the solder strip 60 and the conductor 50. Optionally, the thickness of the conductor 50 between the solder strip 60 and the solder point 20 can be selected from any range between 80μm and 95μm, such as 82μm to 93μm, 85μm to 90μm, 88μm to 93μm, etc. Optionally, the thickness of the conductor 50 between the solder strip 60 and the solder joint 20 can be any value between 80μm and 95μm, such as 82μm, 84μm, 86μm, 88μm, 90μm, 92μm, 94μm, etc.

[0075] Continue to refer to Figure 6In an optional embodiment of the present invention, along the first direction F1, the width of the solder strip is D1, and the distance between the center of the solder strip and the center of the conductor is D0, wherein D0 / D1 ≤ 1 / 4. That is, when the solder strip 60 is welded to the conductor 50, and the center of the solder strip 60 is offset relative to the center of the conductor 50, the aforementioned D0 can be considered as the offset distance. In this embodiment, the offset distance D0 is set to be no greater than 1 / 4 of the solder strip width D1. Considering that when the offset distance of the solder strip 60 relative to the conductor 50 is too large, the contact area between the lower surface of the solder strip 60 and the conductor 50 will be smaller, affecting the reliability of the electrical connection and the reliability of the fixation between the two. When this application sets the offset distance D0 to be no greater than 1 / 4 of the solder strip width D1, it is beneficial to ensure that the lower surface of the solder strip 60 has sufficient contact area with the conductor 50, thus ensuring both the reliability of the electrical connection between the solder strip 60 and the conductor 50 and the reliability of their fixation. When the center of the solder strip 60 is offset relative to the center of the conductor 50, the smaller the offset distance, the better it is to ensure the reliability of the electrical connection and the fixation reliability of the solder strip 60 and the conductor 50. Optionally, D0 / D1≤1 / 5 or D0 / D1≤1 / 6.

[0076] The table below compares the pass rate and welding pull force of the photovoltaic modules in this application and the comparative example. The only difference between the photovoltaic modules in the comparative example and this application is that this application introduces a conductor 50 above solder joint 20, while the comparative example does not. Welding pull force refers to the tensile force that the solder strip can withstand after welding at the corresponding position of a single solder joint. It can be seen that when no conductor is introduced at the solder joint, the product pass rate is less than 80%, indicating an unreliable connection between the solder strip and the solder joint. Furthermore, the tensile force that the solder strip can withstand at a single solder joint is less than 1N, indicating unreliable welding between the solder joint and the solder strip. When a conductor is introduced at the solder joint, the product pass rate can reach 98.5% or higher, effectively improving the pass rate of the photovoltaic modules. Simultaneously, the tensile force that the solder strip can withstand at a single solder joint is greater than 3N, effectively improving the fixing reliability of the solder strip in the product.

[0077] Table 1 Comparison of Acceptance Rate and Welding Tensile Strength of This Application and Comparative Examples

[0078] This application Comparative Example pass rate ≥98.5％ ＜80％ Welding tensile strength ＞3N ＜1N

[0079] As can be seen from the above embodiments, the photovoltaic module provided in this application achieves at least the following beneficial effects:

[0080] The first photovoltaic module structure provided in this application corresponds to the structure before the solder ribbon is welded to the solar cell; the second photovoltaic module structure corresponds to the structure after the solder ribbon is welded to the solar cell. This application introduces insulating portions on both sides of the solder joints of the solar cell. All solder joints arranged along the first direction are isolated by these insulating portions to avoid the potential short circuit problem when the emitter and base of the solar cell are both located on the back side. In addition to the insulating portions, this application also introduces a conductor, which is located between the insulating portions adjacent to the solder joints and does not extend beyond the edge of the solder joints. Before the solder ribbon is welded to the conductor, the conductor is in a first state, in which the center thickness of the conductor is greater than the outer thickness, and the highest point of the conductor is higher than the highest point of the insulating portion. Since the conductor is electrically connected to the solder joint, when the highest point of the conductor is set higher than the highest point of the insulation part, the conductor protrudes from the insulation part before the solder strip is welded to the conductor. Therefore, the solder strip can easily contact the conductor before welding and thus achieve welding with the conductor. This effectively reduces the difficulty of electrical connection between the solder strip and the solder joint, and also helps to improve the reliability of electrical connection between the solder strip and the solder joint, thereby improving the reliability of photovoltaic modules.

[0081] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A photovoltaic module, characterized in that, Includes a battery cell and multiple solder joints located on the first side of the battery cell; It also includes an insulating part and a conductor located on the first side, the insulating part and the conductor being located on the side of the solder joint away from the battery cell; On the first side of the battery cell, the insulating portion is located at least on both sides of the solder joint along a first direction, the first direction being perpendicular to the extension direction of the main grid in the battery cell, and the insulating portion is provided between the solder joints arranged along the first direction; The conductor is electrically connected to the solder joint in a one-to-one correspondence; It also includes a solder strip, through which two adjacent solar cells are electrically connected. The solder strip is located on the side of the conductor away from the solar cell and is soldered to the conductor. The first surface of the solder strip facing the solar cell and at least one side of the solder strip along the first direction are in contact with the conductor. The conductor is in contact with both sides of the solder strip along the first direction, and the center thickness of the conductor is less than the thickness of the opposite edges of the conductor along the first direction.

2. The photovoltaic module according to claim 1, characterized in that, Along the first direction, the width of the solder strip is D1, and the maximum width of the conductor welded to the solder strip is D2, wherein D1≤D2.

3. The photovoltaic module according to claim 1, characterized in that, Along the first direction, the width of the conductor is 1000μm to 1300μm; the edge of the solder strip projected onto the plane of the battery cell includes a first edge, and the edge of the corresponding conductor projected onto the plane of the battery cell includes a second edge. Along the first direction, the first edge and the second edge are located on the same side of the solder strip, and the distance between the first edge and the second edge is 220μm to 350μm.

4. The photovoltaic module according to claim 1, characterized in that, Along the direction perpendicular to the plane where the battery cell is located, the maximum height of the conductor is 100μm to 300μm, and the minimum height of the conductor between the solder strip and the solder joint is 50μm to 65μm.

5. The photovoltaic module according to claim 1, characterized in that, The conductor contacts a first side of the solder strip along the first direction, but does not contact a second side of the solder strip along the first direction, wherein the first side and the second side are opposite to each other.

6. The photovoltaic module according to claim 5, characterized in that, Along the first direction, the width of the conductor is 1300μm to 1500μm; the edge of the solder strip that contacts the conductor in the orthographic projection of the plane where the battery cell is located is the third edge, and the edge of the conductor that does not contact the solder strip in the orthographic projection of the plane where the battery cell is located is the fourth edge; along the first direction, the distance between the third edge and the fourth edge is 450μm to 550μm.

7. The photovoltaic module according to claim 5, characterized in that, Along a direction perpendicular to the plane where the battery cell is located, the maximum height of the conductor is 130μm to 150μm, and the minimum height of the conductor between the solder strip and the solder joint is 80μm to 95μm.

8. The photovoltaic module according to claim 5, characterized in that, Along the first direction, the width of the solder strip is D1, and the distance between the center of the solder strip and the center of the conductor is D0, wherein D0 / D1≤1 / 4.

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