Back contact photovoltaic module

Abstract

The embodiment of the invention relates to the photovoltaic field, and provides a back contact photovoltaic module, which comprises a battery piece body, the back surface of which is provided with first and second fine grids which are alternately arranged along a first direction, and first and second main grids which are alternately arranged along a second direction; a plurality of bonding pads, wherein a single bonding pad is located at the disconnected part of the first fine grid and connected with the second main grid or located at the disconnected part of the second fine grid and connected with the first main grid; a plurality of first insulating strips extending along a second direction, wherein at least two first insulating strips form a first insulating group corresponding to a bonding pad; at least two first insulating strips in a single first insulating group are respectively positioned on two opposite sides of the bonding pad along the first direction, any first insulating strip comprises a communication part, and the communication part covers a partial region of the main grid and end parts of two branches of one fine grid disconnected by the main grid; at least one first insulating strip comprises a protruding part protruding towards the bonding pad so as to cover a partial area of the fine grid close to the bonding pad, and at least improvement of the structural stability of the back contact photovoltaic module is facilitated.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the photovoltaic field, and in particular to a back-contact photovoltaic module. Background Art

[0002] At present, with the gradual depletion of fossil energy, photovoltaic cells are increasingly used as a new energy alternative. Photovoltaic cells are devices that convert sunlight into electrical energy. Photovoltaic cells use the principle of photovoltaics to generate carriers, and then use electrodes to lead out the carriers, thereby facilitating the effective use of electrical energy. The grid lines of photovoltaic cells play an important role in collecting and transmitting electrons. When multiple photovoltaic cells are assembled to obtain a photovoltaic module, welding strips are often used to connect the grid lines of adjacent cells.

[0003] In a back-contact photovoltaic module, the main grid collects the current on the fine grid. The main grid is provided with a welding pad, and the welding strip is electrically connected to the main grid through the welding pad to collect the current on the main grid. The welding strip and the fine grid are arranged in different directions. Therefore, when the welding strip is connected to the fine grid of the same polarity, it also needs to cross the fine grid of different polarity. In order to prevent the short circuit caused by the welding strip connecting the fine grids of different polarities, it is necessary to design an insulating strip on the fine grid of different polarity from the welding strip.

[0004] However, the design of the insulating strip not only affects the stress caused by the connection between the welding ribbon and the welding pad on the solar cell, but also affects the conductive performance of the fine grid near the welding pad, for example, causing the welding ribbon to bend too much, the solar cell to warp seriously, or some main grids or fine grids to break, thereby affecting the structural stability of the back-contact photovoltaic module. Summary of the invention

[0005] The embodiments of the present disclosure provide a back-contact photovoltaic module, which is at least beneficial to improving the structural stability of the back-contact photovoltaic module.

[0006] According to some embodiments of the present disclosure, on one hand, the embodiments of the present disclosure provide a back-contact photovoltaic module, including: a battery cell body, wherein the back side of the battery cell body is provided with first fine grids and second fine grids alternately arranged along a first direction, and first main grids and second main grids alternately arranged along a second direction, the first fine grids are disconnected at the second main grid, and the second fine grids are disconnected at the first main grid; a plurality of welding pads, a single welding pad is located at the disconnection of the first fine grid and connected to the second main grid, or is located at the disconnection of the second fine grid and connected to the first main grid; a plurality of first insulating strips extending along the second direction, at least two of the first insulating strips being a first insulating group, the first insulating group being connected to the welding pads One corresponds to another; in a single first insulation group, at least two first insulation strips are respectively located on opposite sides of the pad along the first direction, and any first insulation strip at least includes a connecting portion, the connecting portion covers a partial area of ​​the main grid connected to the pad, and covers two ends of two branches of a fine grid disconnected by the main grid, the main grid is one of the first main grid and the second main grid, and the fine grid is one of the first fine grid and the second fine grid; wherein, at least one of the first insulation strips close to the pad also includes a protruding portion protruding toward the pad, and the protruding portion covers a partial area of ​​one of the fine grids located between the pad and the first insulation strip.

[0007] In some embodiments, the back-contact photovoltaic module also includes: a plurality of welding strips arranged at intervals along the second direction, and one of the welding strips is located on one of the main grids, and the welding strip is connected to at least the welding pad; the raised portion also covers a partial area of ​​the main grid connected to the welding pad, and the plane formed by the first direction and the second direction is used as a reference plane, and among the raised portions and the welding strips corresponding to the same main grid, the orthographic projection of the raised portion on the reference plane overlaps with the orthographic projection of the welding strip on the reference plane.

[0008] In some embodiments, along the second direction, the length of the protruding portion is a first length, the length of the connecting portion is a second length, and the ratio of the first length to the second length is 1 / 5 to 1 / 2.

[0009] In some embodiments, along the first direction, the width of the protruding portion is a first width, the width of the connecting portion is a second width, and the ratio of the first width to the second width is 1 / 2 to 1 / 1.

[0010] In some embodiments, the two opposite sides of the solder pad along the first direction are respectively an upper side and a lower side, and one of the first insulating strips closest to the upper side and / or the lower side includes the connecting portion and the protruding portion; wherein, along the first direction, the spacing between the solder pad and the protruding portion is greater than or equal to 0.20 mm.

[0011] In some embodiments, any first insulating strip includes at least the connecting portion and at least one extension portion, and a single extension portion connects one of the two opposite ends of the connecting portion along the second direction; wherein, along the first direction, the width of the connecting portion is the second width, the width of the extension portion is the third width, and the second width is greater than the third width.

[0012] In some embodiments, the two opposite sides of the pad along the first direction are respectively an upper side and a lower side, at least two of the connecting portions are arranged at intervals close to one of the upper side and the lower side, and in a direction away from the pad, the lengths of at least two of the connecting portions in the second direction gradually decrease.

[0013] In some embodiments, along the direction away from the pad, the thickness of at least the connecting portion farthest from the pad in the third direction gradually decreases; and / or, at least two of the connecting portions spaced apart along one of the two sides opposite to each other along the first direction close to the pad are taken as a connecting group, and in a single connecting group, along the direction away from the pad, the thickness of at least two of the connecting portions in the third direction gradually decreases; the third direction is the thickness direction of the battery cell body.

[0014] In some embodiments, the back-contact photovoltaic module further includes: at least one connection portion extending along the first direction, one end of the connection portion is connected to one of the fine grids located between the pad and the first insulating strip, and the other end of the connection portion is connected to the pad.

[0015] In some embodiments, the back-contact photovoltaic module also includes: a plurality of second insulating strips extending along the second direction, a single second insulating strip being located on one of the two opposite sides of the pad along the second direction, and covering at least a portion of the area of ​​one of the two branches of the fine grid disconnected by the pad; and / or a plurality of third insulating strips extending along the second direction, the third insulating strips being located on the side of the first insulating strip away from the pad, a single third insulating strip only covering at least a portion of the area of ​​one of the two branches of the fine grid disconnected by the main grid.

[0016] The technical solution provided by the embodiments of the present disclosure has at least the following advantages:

[0017] The first insulating strip is designed to include a connecting portion, which can not only ensure that the subsequent welding strip connected to the welding pad will not contact the end of the disconnected portion of the heterogeneous fine grid, avoiding the short circuit problem between the first fine grid and the second fine grid, but also provide a higher support point for the welding strip, so that the welding strip is supported by the welding pad and the connecting portion along the second direction, which is conducive to increasing the portion of the welding strip that is raised as a whole. In this way, on the one hand, it is conducive to avoiding excessive bending of the welding strip itself; on the other hand, it is conducive to reducing the risk of the welding strip causing greater stress to the main grid and fine grid adjacent to it, making it easy to break; on the other hand, the connecting portion covers the main grid, which is conducive to avoiding the risk of the raw materials of the welding strip melting and dripping down onto the main grid under high temperature conditions, so as to avoid the main grid breaking phenomenon caused by the raw materials of the welding strip melting under high temperature conditions, so as to further reduce the risk of the main grid breaking. Moreover, it is designed that at least one first insulating strip close to the welding pad also includes a protruding portion protruding toward the welding pad, and the protruding portion covers a partial area of ​​a fine grid located between the welding pad and the first insulating strip, which can effectively avoid the fine grid breaking here.

[0018] In summary, under the multi-faceted effects of the first insulating strip, it is not only helpful to effectively reduce the risk of fine grid or main grid breakage, but also helpful to reduce the bending degree of the welding strip itself, so as to reduce the stress generated by the welding strip on the battery cell body, thereby effectively improving the structural stability of the back contact photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings, and these exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise specified, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the traditional technology, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A first partial top view schematic diagram of a back-contact photovoltaic assembly provided by an embodiment of the present disclosure;

[0021] Figure 2 A partial cross-sectional schematic diagram of a back-contact photovoltaic module provided by an embodiment of the present disclosure;

[0022] Figure 3 A second partial top view schematic diagram of a back-contact photovoltaic assembly provided by an embodiment of the present disclosure;

[0023] Figure 4 A schematic top view of a first insulating strip in a back-contact photovoltaic module provided by an embodiment of the present disclosure;

[0024] Figure 5 A third partial top view schematic diagram of a back-contact photovoltaic module provided by an embodiment of the present disclosure;

[0025] Figure 6 Another schematic top view of a first insulating strip in a back-contact photovoltaic module provided by an embodiment of the present disclosure;

[0026] Figure 7 A fourth partial top view schematic diagram of a back-contact photovoltaic module provided by an embodiment of the present disclosure;

[0027] Figure 8 Another partial cross-sectional schematic diagram of a back-contact photovoltaic module provided by an embodiment of the present disclosure;

[0028] Fig. 9 A schematic partial cross-sectional view of another embodiment of a back-contact photovoltaic module provided by the present disclosure;

[0029] Fig.10 A fifth partial top view schematic diagram of a back-contact photovoltaic module provided by an embodiment of the present disclosure;

[0030] Fig.11 A sixth partial top view schematic diagram of a back-contact photovoltaic module provided by an embodiment of the present disclosure;

[0031] Fig.12 A schematic cross-sectional view of a second insulating strip in a back-contact photovoltaic module provided by an embodiment of the present disclosure;

[0032] Fig.13 A schematic cross-sectional view of a third insulating strip in a back-contact photovoltaic module provided by an embodiment of the present disclosure;

[0033] Fig.14 A partial top view schematically showing the insulating strips and fine grids corresponding to each other in a back-contact photovoltaic module provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0034] As can be seen from the background technology, the structural stability of back-contact photovoltaic modules needs to be improved.

[0035] The present disclosure provides a back-contact photovoltaic module, and the first insulating strip is designed to include a connecting portion, which can not only ensure that the welding strip connected to the welding pad later will not contact the end of the disconnected part of the opposite-sex fine grid, avoiding the short circuit problem between the first fine grid and the second fine grid, but also provide a higher support point for the welding strip, so that the welding strip is supported by the welding pad and the connecting portion in the second direction, which is conducive to increasing the portion of the welding strip that is raised as a whole. In this way, on the one hand, it is conducive to avoiding excessive bending of the welding strip itself; on the other hand, it is conducive to reducing the risk of the welding strip causing greater stress to the main grid and fine grid adjacent to it, making it easy to break; on the other hand, the connecting portion covers the main grid, which is conducive to avoiding the risk of the raw material of the welding strip melting and dripping down onto the main grid under high temperature conditions, so as to avoid the main grid being broken due to the raw material of the welding strip melting under high temperature conditions, so as to further reduce the risk of the main grid breaking. Moreover, it is designed that at least one first insulating strip close to the welding pad also includes a protruding portion protruding toward the welding pad, and the protruding portion covers a partial area of ​​a fine grid located between the welding pad and the first insulating strip, which can effectively avoid the fine grid breaking here. Therefore, under the multi-faceted effects of the first insulating strip, it is not only helpful to effectively reduce the risk of fine grid or main grid breakage, but also helpful to reduce the bending degree of the welding strip itself, so as to reduce the stress generated by the welding strip on the battery cell body, thereby effectively improving the structural stability of the back-contact photovoltaic module.

[0036] In the description of the embodiments of the present disclosure, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present disclosure, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0037] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present disclosure. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0038] In the description of the embodiments of the present disclosure, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0039] In the description of the embodiments of the present disclosure, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0040] In the description of the embodiments of the present disclosure, the orientations or positional relationships indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present disclosure and simplifying the description. They do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the embodiments of the present disclosure.

[0041] In the description of the embodiments of the present disclosure, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to the specific circumstances.

[0042] In the accompanying drawings corresponding to the embodiments of the present disclosure, the thickness and area of ​​the layers are magnified for better understanding and ease of description. When describing a component (such as a layer, a film, a region or a substrate) on another component or on the surface of another component, the component may be "directly" located on the surface of the other component, or a third component may be present between the two components. On the contrary, when describing a component on the surface of another component or when another component is formed or provided on the surface of a component, it means that there is no third component between the two components. In addition, when describing a component as being "substantially" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a partial edge of the entire surface.

[0043] In the description of the embodiments of the present disclosure, when a component "includes" another component, unless otherwise specified, other components are not excluded, and other components may be further included. In addition, when a component such as a layer, film, region, or plate is referred to as being "on / located on" another component, it may be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component may exist therebetween. In addition, when a component such as a layer, film, region, or plate is "directly located on" another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it means that no other components are located therebetween.

[0044] The terms used in the description of the various embodiments described herein are only used to describe specific embodiments and are not intended to be limiting. As used in the description of the various embodiments described and in the appended claims, "the components" are also intended to include plural forms unless the context clearly indicates otherwise. Among them, components include components such as layers, films, regions, or plates.

[0045] The following will describe the various embodiments of the present disclosure in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the various embodiments of the present disclosure, many technical details are provided in order to enable the reader to better understand the embodiments of the present disclosure. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the embodiments of the present disclosure can be implemented.

[0046] An embodiment of the present disclosure provides a back-contact photovoltaic module, which will be described in detail below with reference to the accompanying drawings.

[0047] Combined with reference Figures 1 to 3The back-contact photovoltaic module comprises: a cell body 100, a back side 100a of the cell body 100 is provided with first fine grids 111 and second fine grids 121 arranged alternately along a first direction X, a first main grid 112 and a second main grid 122 arranged alternately along a second direction Y, the first fine grid 111 is disconnected at the second main grid 122, and the second fine grid 121 is disconnected at the first main grid 112; a plurality of pads 103, a single pad 103 is located at the disconnection of the first fine grid 111 and connected to the second main grid 122, or is located at the disconnection of the second fine grid 121 and connected to the first main grid 112; a plurality of first insulating strips 104 extending along the second direction Y, at least two first insulating strips 104 are used as a first insulating group 114, and the first insulating group 114 corresponds to the pads 103 one by one; a single In the first insulation group 114, at least two first insulation strips 104 are respectively located on opposite sides of the pad 103 along the first direction X, and any first insulation strip 104 includes at least a connecting portion 124, the connecting portion 124 covers a partial area of ​​the main grid 102 connected to the pad 103, and covers two ends of two branches of a fine grid 101 disconnected by the main grid 102, the main grid 102 is one of the first main grid 112 and the second main grid 122, and the fine grid 101 is one of the first fine grid 111 and the second fine grid 121; wherein, at least one first insulation strip 104 close to the pad 103 also includes a protruding portion 134 protruding toward the pad 103, and the protruding portion 134 covers a partial area of ​​a fine grid 101 located between the pad 103 and the first insulation strip 104.

[0048] It is worth noting that, based on the difference in polarity, the fine grid 101 can be divided into two types: a first fine grid 111 and a second fine grid 121, and the main grid 102 can be divided into two types: a first main grid 112 and a second main grid 122. The first main grid 112 is used to collect currents on all the first fine grids 111, and the second main grid 122 is used to collect currents on all the second fine grids 121. Based on this, the plurality of pads 103 can also be divided into two types: a first pad 113 and a second pad 123. The first pad 113 is located at the disconnection of the second fine grid 121 and is connected to the first main grid 112, and the second pad 123 is located at the disconnection of the first fine grid 111 and is connected to the second main grid 122. The disconnection of the second fine grid 121 is used for the first main grid 112 to extend along the first direction X and be electrically connected to the plurality of first fine grids 111, and the disconnection of the first fine grid 111 is used for the second main grid 122 to extend along the first direction X and be electrically connected to the plurality of second fine grids 121.

[0049] Furthermore, based on the different types of connected pads 103, the soldering strip 105 described later can also be divided into two types: a first soldering strip 115 and a second soldering strip 125. The first soldering strip 115 is connected to the first soldering pad 113 to collect the current on the first main grid 112, and the second soldering strip 125 is connected to the second soldering pad 123 to collect the current on the second main grid 122.

[0050] It should be noted that Figure 1 A first partial top view schematic diagram of a back-contact photovoltaic assembly provided by an embodiment of the present disclosure, Figure 2 A partial cross-sectional schematic diagram of a back-contact photovoltaic module provided by an embodiment of the present disclosure, Figure 3 This is a second partial top view of a back-contact photovoltaic module provided by an embodiment of the present disclosure. To facilitate the distinction between the first fine grid 111 and the second fine grid 121, Figure 1 and Figure 2 In the figure, the first fine grid 111 is indicated by a thick solid line, and the second fine grid 121 is indicated by a thick dotted line. Figure 1 In the figure, the first insulating strip 104 is drawn in a perspective manner. In addition, just as the thin grid 101 refers to one of the first thin grid 111 and the second thin grid 121, and the main grid 102 refers to one of the first main grid 112 and the second main grid 122, the pad 103 described in the subsequent paragraphs may refer to one of the first pad 113 or the second pad 123, and the welding strip 105 may refer to one of the first welding strip 115 or the second welding strip 125.

[0051] In addition, in order to clearly illustrate the positional relationship between the main grid 102, the fine grid 101 and the pad 103, Figure 3 Only two welding strips 105 are shown, and the welding strips 105 are drawn in a perspective manner.

[0052] It is worth noting that in the back-contact photovoltaic module provided by an embodiment of the present disclosure, the insulating strips are specially designed for the surroundings of the pads 103. Specifically, a first insulating group 114 corresponding to the pads 103 is designed. In a single first insulating group 114, at least two first insulating strips 104 are respectively located on two opposite sides of the pads 103 along the first direction X, that is, at least one first insulating strip 104 is provided on both opposite sides of the pads 103 along the first direction X. Moreover, any first insulating strip 104 includes at least a connecting portion 124, which not only covers a partial area of ​​the main grid 102 connected to the pads 103, but also covers two ends of two branches of a thin grid 101 disconnected by the main grid 102. In other words, near the pads 103, the disconnected portion of a thin grid 101 disconnected by the main grid 102 electrically connected to the pads 103 is also covered with the first insulating strip 104.

[0053] In this way, the connecting portion 124 can not only ensure that the soldering ribbon 105 subsequently connected to the soldering pad 103 will not contact the end of the disconnected portion of the heterogeneous fine grid to avoid causing a short circuit problem between the first fine grid 111 and the second fine grid 121, but also provide a higher supporting point for the soldering ribbon 105.

[0054] In some cases, in conjunction with reference Figure 2 and Figure 3 The soldering tape 105 includes a soldering tape body 135 and a solder paste 145. When the soldering tape 105 is connected, for example, soldered to the pad 103, the solder paste 145 in the soldering tape 105 electrically connects the soldering tape body 135 and the pad 103. However, along the third direction Z, the pad 103 overlaps the main grid 102, and based on the solder paste 145 in the soldering tape 105, there is a certain height difference between the soldering tape 105 and the main grid 102. The connecting portion 124 is also designed to overlap the main grid 102, so that more areas of the subsequently formed soldering tape 105 along the second direction Y can be supported by higher support points. In other words, not only the portion of the soldering tape body 135 in the soldering tape 105 that is in contact with the pad 103 is raised, but also the portion that is in contact with the connecting portion 124 is raised, which is beneficial to increase the portion of the soldering tape body 135 that is raised as a whole. In this way, on the one hand, it is helpful to avoid the local bending degree of the welding strip body 135 itself being too large, that is, from the perspective of the entire welding strip 105, the bending degree of the welding strip body 135 per unit length is reduced, and it is not only the welding strip body 135 at the contact connection with the pad 103 that is raised. In other words, it is helpful to slow down the bending trend of the welding strip body 135; on the other hand, it is helpful to avoid the local bending degree of the welding strip body 135 itself being too large, which is helpful to reduce the risk of the welding strip 105 causing greater stress to the adjacent main grid 102 and fine grid 101 and making them easy to break; on the other hand, the connecting portion 124 covers the main grid 102, which is helpful to avoid the risk of the raw material of the welding strip 105 melting and dripping down onto the main grid 102 under high temperature conditions, and avoid the main grid 102 being broken due to the raw material of the welding strip 105 melting under high temperature conditions, so as to further reduce the risk of the main grid 102 breaking. Among them, the third direction Z is the thickness direction of the battery cell body 100. It is worth emphasizing that the bending degree of the soldering ribbon 105 described in the subsequent paragraphs mainly refers to the bending degree of the soldering ribbon body 135 in the soldering ribbon 105 .

[0055] Furthermore, at least one first insulating strip 104 near the pad 103 is designed to include a protruding portion 134 protruding toward the pad 103, and the protruding portion 134 covers a partial area of ​​a fine grid 101 located between the pad 103 and the first insulating strip 104. In other words, the protruding portion 134 covers a partial area of ​​a fine grid 101 near the pad 103 and electrically connected to the pad 103. Since the fine grid 101 is closest to the pad 103, when the soldering strip 105 is contacted and connected, for example, soldered to the pad 103, the portion of the soldering strip 105 located directly above the fine grid 101 is also greatly affected by the temperature. The protruding portion 134 is designed to cover the fine grid 101 at this location, which can effectively prevent the fine grid 101 at this location from breaking.

[0056] In summary, under the multi-faceted effects of the first insulating strip 104, it is not only helpful to effectively reduce the risk of breakage of the fine grid 101 or the main grid 102, but also helpful to reduce the bending degree of the welding strip 105 itself, so as to reduce the stress generated by the welding strip 105 on the battery cell body 100, thereby effectively improving the structural stability of the back-contact photovoltaic module.

[0057] It is worth emphasizing that each first insulating strip 104 includes a connecting portion 124, and each connecting portion 124 only covers a thin grid 101 of the opposite sex that is disconnected by the main grid 102. Moreover, the first insulating strip 104 is designed only on a portion of the thin grids 101 close to the pad 103 along the first direction X. In this way, compared with laying a large area of ​​insulating material around the pad, it is beneficial to make the first insulating strip 104 cover the areas on the main grid 102 and the thin grid 101 that are prone to breakage as much as possible, so as to reduce the risk of breakage of the main grid 102 and the thin grid 101, and reduce the bending degree of the subsequent solder strip 105 electrically connected to the pad 103, while reducing the total layout area occupied by the first insulating strip 104 on the battery cell body 100, so as to reduce the amount of insulating material required to form the first insulating strip 104, thereby helping to reduce the preparation cost of the first insulating strip 104 and avoid the warping problem of the back-contact photovoltaic module caused by the volume shrinkage of a large area of ​​insulating material.

[0058] In addition, each first insulating strip 104 includes a connecting portion 124, but only a part of the first insulating strips 104 also include a protruding portion 134, for example, only the first insulating strips 104 closest to the pad 103 along the first direction X include a protruding portion 134, and in a single first insulating group 114, only two first insulating strips 104 include protruding portions 134 and are respectively located on opposite sides of the pad 103 along the first direction X. In this way, the risk of the fine grid 101 closest to the pad 103 being broken can be effectively reduced, and the total layout area of ​​the first insulating strips 104 on the battery cell body 100 can be reduced as much as possible.

[0059] The embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0060] In some embodiments, in conjunction with reference Figure 1 and Figure 3 The back-contact photovoltaic module may also include: a plurality of welding strips 105 arranged at intervals along the second direction Y, and one welding strip 105 is located on one main grid 102, and the welding strip 105 is connected to at least the welding pad 103; the raised portion 134 also covers a partial area of ​​the main grid 102 connected to the welding pad 103, and the plane formed by the first direction X and the second direction Y is used as the reference plane, and in the raised portions 134 and welding strips 105 corresponding to the same main grid 102, the orthographic projection of the raised portion 134 on the reference plane overlaps with the orthographic projection of the welding strip 105 on the reference plane.

[0061] It is worth noting that when the welding ribbon 105 is contacted and connected, for example, welded to the pad 103, not only the fine grid 101 closer to the pad 103 is easily affected by the raw materials melted by the welding ribbon 105 under high temperature conditions, but also the main grid 102 closer to the pad 103 is easily affected by the raw materials melted by the welding ribbon 105 under high temperature conditions. Therefore, the design of the protrusion 134 not only covers a part of the fine grid 101 closest to the pad 103 and electrically connected thereto, but also covers a part of the main grid 102 connected to the pad 103, which is conducive to using the protrusion 134 to simultaneously protect the parts of the main grid 102 and the fine grid 101 that are prone to breakage, so as to further improve the structural stability of the back contact photovoltaic module.

[0062] Generally speaking, the fine grid 101 and the main grid 102 located directly below the welding strip 105 are most susceptible to the influence of the raw materials melted by the welding strip 105 under high temperature conditions. Therefore, in the design of the raised portion 134 and the welding strip 105 corresponding to the same main grid 102, the orthographic projection of the raised portion 134 on the reference plane overlaps with the orthographic projection of the welding strip 105 on the reference plane, which is beneficial to ensure that the raised portion 134 is provided in at least a partial area directly below the welding strip 105, thereby facilitating the raised portion 134 to accurately protect the fine grid 101 and the main grid 102.

[0063] It should be noted that the overlapping of the orthographic projection of the raised portion 134 on the reference surface and the orthographic projection of the solder strip 105 on the reference surface includes at least the following situations: in some situations, the orthographic projection of the raised portion 134 on the reference surface is located in the orthographic projection of the solder strip 105 on the reference surface; in other situations, the orthographic projection of the solder strip 105 on the reference surface is located in the orthographic projection of the raised portion 134 on the reference surface; in still other situations, the orthographic projection of the raised portion 134 on the reference surface only partially overlaps with the orthographic projection of the solder strip 105 on the reference surface.

[0064] In some embodiments, reference Figure 4 , Figure 4A top view schematic diagram of the first insulating strip in the back-contact photovoltaic module provided for an embodiment of the present disclosure, along the second direction Y, the length of the protrusion 134 is the first length L1, the length of the connecting portion 124 is the second length L2, and the ratio of the first length L1 to the second length L2 can be 1 / 5 to 1 / 2. For example, the ratio of the first length L1 to the second length L2 can be 1 / 4, 3 / 10, 1 / 3 or 2 / 5, etc.

[0065] Combined with reference Figure 1 and Figure 4 If the ratio of the first length L1 to the second length L2 is less than 1 / 5, the area covered by the protrusion 134 in the fine grid 101 adjacent to the pad 103 along the first direction X is small, which is not conducive to improving the protection effect of the protrusion 134 on the fine grid 101; if the ratio of the first length L1 to the second length L2 is greater than 1 / 2, the total layout area of ​​the protrusion 134 on the battery cell body 100 is large, which will affect the total layout area of ​​the first insulating strip 104 on the battery cell body 100, which is not conducive to reducing the volume of the first insulating strip 104 and preventing the back contact photovoltaic module from warping. In this way, the ratio of the first length L1 to the second length L2 can be designed to be 1 / 5 to 1 / 2, which is conducive to ensuring the good protection effect of the protrusion 134 on the fine grid 101, so as to effectively reduce the risk of the fine grid 101 breaking, and reduce the volume of the first insulating strip 104 to prevent the back contact photovoltaic module from serious warping.

[0066] It should be noted that Figure 4 The protrusion 134 and the connecting portion 124 included in the first insulating strip 104 are divided by dotted lines.

[0067] In some examples, along the second direction Y, the first length L1 of the protrusion 134 may be greater than or equal to 0.20 mm. For example, the first length L1 may be 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.42 mm, 0.45 mm or 0.5 mm, etc., to ensure that the protrusion 134 has a good protective effect on the fine grid 101.

[0068] In some examples, along the second direction Y, the second length L2 of the connecting portion 124 can be 1 mm to 9 mm. For example, the second length L2 can be 1.5 mm, 1.8 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm or 8.5 mm, etc.

[0069] Combined with reference Figure 1 and Figure 4 If the second length L2 is less than 1 mm, the length of the connecting portion 124 is short, and the connecting portion 124 is close to the welding strip 105 (reference Figure 3) has limited supporting strength. When placing the soldering ribbon 105 on the soldering pad 103 and connecting the soldering ribbon 105, such as welding it to the soldering pad 103, due to the small supporting area of ​​the connecting portion 124 for the soldering ribbon 105, the soldering ribbon 105 is prone to unstable placement, such as tilting, resulting in a relative offset between the soldering ribbon 105 and the soldering pad 103. In addition, the shorter connecting portion 124 has a smaller buffering effect on the stress, which can easily cause a larger local stress on the battery cell body 100 during welding. If the second length L2 is greater than 9 mm and the length of the connecting portion 124 is longer, the total layout area of ​​the connecting portion 124 on the battery cell body 100 is larger, which will affect the total layout area of ​​the first insulating strip 104 on the battery cell body 100, and is not conducive to reducing the volume of the first insulating strip 104, nor is it conducive to preventing the back-contact photovoltaic module from warping. In this way, the second length L2 can be designed to be 1mm to 9mm, which is beneficial to ensure that the connecting portion 124 has sufficient supporting strength for the welding strip 105 and a good stress buffering effect, so as to effectively avoid the relative offset and stress concentration problems between the welding strip 105 and the pad 103, while reducing the volume of the first insulating strip 104 to prevent serious warping of the back-contact photovoltaic module.

[0070] It should be noted that, along the second direction Y, in different first insulating strips 104, the ratio of the length of the protrusion 134 to the length of the connecting portion 124 may be the same or different; in different first insulating strips 104, the lengths of different protrusions 134 may be the same or different; in different first insulating strips 104, the lengths of different connecting portions 124 may be the same or different.

[0071] In some embodiments, continue to refer to Figure 4 Along the first direction X, the width of the protrusion 134 is a first width W1, and the width of the connecting portion 124 is a second width W2. The ratio of the first width W1 to the second width W2 can be 1 / 2 to 1 / 1. For example, the ratio of the first width W1 to the second width W2 can be 3 / 5, 7 / 10, 4 / 5 or 9 / 10, etc.

[0072] It is worth noting that, combined with reference Figure 1 and Figure 4In the same first insulating strip 104 , the ratio of the first width W1 to the second width W2 represents the degree to which the protrusion 134 protrudes relative to the connecting portion 124 . If the ratio of the first width W1 to the second width W2 is less than 1 / 2, the protrusion 134 is less protruding relative to the connecting portion 124, the width of the portion of the protrusion 134 between the pad 103 and the fine grid 101 closest to the pad 103 is smaller, and the protrusion 134 of this portion is at the edge of the first insulating strip 104, and the thickness of the edge is easily reduced due to the overflow of glue, which affects the thickness of the protrusion 134 located around the fine grid 101, thereby affecting the protective effect of the protrusion 134 on the fine grid 101; if the ratio of the first width W1 to the second width W2 is greater than 1 / 1, the protrusion 134 is more protruding relative to the connecting portion 124, and the distance between the protrusion 134 and the pad 103 is smaller, and the insulating material constituting the protrusion 134, such as the insulating glue, is easy to overflow onto the pad 103, and the soldering strip 105 is welded on the pad 103 (refer to Figure 3 ), the raw material of the soldering ribbon 105, such as solder paste, is easily affected by the insulating glue overflowing onto the pad 103 and is divided into two halves, thereby causing poor contact between the soldering ribbon 105 and the pad 103.

[0073] In this way, the ratio of the first width W1 and the second width W2 can be designed to be 1 / 2 to 1 / 1, which is beneficial for ensuring that the thickness of the raised portion 134 located around the fine grid 101 will not be too thin, so as to ensure that the raised portion 134 has a good protective effect on the fine grid 101, and is beneficial for ensuring that there is a suitable spacing between the raised portion 134 and the pad 103, effectively preventing the insulating material constituting the raised portion 134 from overflowing onto the pad 103, so as to avoid poor contact between the solder strip 105 and the pad 103.

[0074] In some examples, along the first direction X, the first width W1 of the protrusion 134 can be 0.2mm~0.3mm, for example, the first width W1 can be 0.22mm, 0.24mm, 0.25mm, 0.26mm or 0.28mm, etc.; the second width W2 of the connecting portion 124 can be 0.3mm~0.5mm, for example, the second width W2 can be 0.32mm, 0.34mm, 0.35mm, 0.36mm, 0.38mm, 0.4mm, 0.42mm, 0.44mm, 0.45mm, 0.46mm or 0.48mm, etc.

[0075] It should be noted that, along the first direction X, in different first insulating strips 104, the ratio of the width of the protrusion 134 to the width of the connecting portion 124 may be the same or different; in different first insulating strips 104, the widths of different protrusions 134 may be the same or different; in different first insulating strips 104, the widths of different connecting portions 124 may be the same or different.

[0076] In some embodiments, reference Figure 1 The two opposite sides of the pad 103 along the first direction X are respectively an upper side 103a and a lower side 103b, and a first insulating strip 104 closest to the upper side 103a and / or the lower side 103b includes a connecting portion 124 and a protruding portion 134; wherein, along the first direction X, a spacing S between the pad 103 and the protruding portion 134 is greater than or equal to 0.20 mm.

[0077] It should be noted that Figure 1 In the example, a first insulating strip 104 closest to the upper side 103a includes a connecting portion 124 and a protruding portion 134, and a first insulating strip 104 closest to the lower side 103b also includes a connecting portion 124 and a protruding portion 134. In practical applications, only a first insulating strip closest to the upper side may include a connecting portion and a protruding portion, while other first insulating strips may not include a protruding portion; or only a first insulating strip closest to the lower side may include a connecting portion and a protruding portion, while other first insulating strips may not include a protruding portion.

[0078] It is worth emphasizing that along the first direction X, the spacing S between the pad 103 and the protrusion 134 is designed to be greater than or equal to 0.20 mm. For example, the spacing S can be 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.42 mm, 0.45 mm or 0.5 mm, etc., which is beneficial to effectively prevent the insulating material constituting the protrusion 134 from overflowing onto the pad 103, so as to avoid poor contact between the soldering strip 105 and the pad 103, thereby improving the structural stability of the back-contact photovoltaic module.

[0079] In some embodiments, in conjunction with reference Figure 5 and Figure 6 Any first insulating strip 104 includes at least a connecting portion 124 and at least one extending portion 144, and a single extending portion 144 connects one of the two opposite ends of the connecting portion 124 along the second direction Y; wherein, along the first direction X, the width of the connecting portion 124 is the second width W2, the width of the extending portion 144 is the third width W3, and the second width W2 is greater than the third width W3.

[0080] It is worth noting that any first insulating strip 104, whether or not it includes the protrusion 134, includes the connecting portion 124 and at least one extending portion 144, and only a portion of the first insulating strips 104 include the protrusion 134. In addition, the third width W3 of the extending portion 144 is designed to be smaller than the second width W2 of the connecting portion 124, which is beneficial for improving the insulating effect of the first insulating strip 104 on the fine grid 101 covered by the extending portion 144, while reducing the amount of insulating material required to form the extending portion 144, so as to reduce the amount of insulating material required to form the first insulating strip 104, thereby reducing the preparation cost of the first insulating strip 104 and avoiding the warping problem of the back contact photovoltaic module caused by the volume shrinkage of the large area insulating material.

[0081] in, Figure 5 A third partial top view schematic diagram of a back-contact photovoltaic module provided by an embodiment of the present disclosure, Figure 6 Another schematic top view of the first insulating strip in the back contact photovoltaic module provided by an embodiment of the present disclosure. It should be noted that: Figure 5 and Figure 1 The same or similar parts will not be repeated here. Figure 6 and Figure 4 The same or similar parts will not be described in detail here.

[0082] In some cases, continue to refer to Figure 5 and Figure 6 , any first insulating strip 104 includes a connecting portion 124 and two extending portions 144, and the two extending portions 144 respectively connect the two opposite ends of the connecting portion 124 along the second direction Y, so as to improve the integrity and symmetry of the insulating effect of the first insulating strip 104 on the fine gate 101 covered by it. In other cases, any first insulating strip may also include a connecting portion and an extending portion, and the extending portion connects one of the two opposite ends of the connecting portion along the second direction.

[0083] In some embodiments, reference Figure 1 or Figure 5 , the two opposite sides of the pad 103 along the first direction X are the upper side 103a and the lower side 103b, respectively, and the number of the connecting portions 124 arranged at intervals along one of the upper side 103a and the lower side 103b is 1 to 6. In other words, at least two connecting portions 124 arranged at intervals along one of the two opposite sides of the pad 103 along the first direction X are taken as a connecting group 154, and the number of connecting portions 124, i.e., the number of first insulating strips 104, included in a single connecting group 154 ​​is 1 to 6, and the number of connecting portions 124, i.e., the number of first insulating strips 104 included in a single first insulating group 114 is 2 to 12.

[0084] It is worth noting that in the process of welding the soldering strip 105 on the soldering pad 103, the portion of the soldering strip 105 located near the soldering pad 103 is greatly affected by the temperature. By covering the connecting portion 124 on the main grid 102 that is opposite to the portion of the soldering strip 105 that is greatly affected by the temperature along the third direction Z and the heterogeneous fine grid 101 that is insulated from the main grid 102, the risk of the fine grid 101 and the main grid 102 breaking can be significantly reduced, and the degree of bending of the soldering strip 105 caused by the height difference between the soldering pad 103 and the main grid 102 can be significantly reduced, and there is no need to design the first insulating strip 104 including the connecting portion 124 in the area far away from the soldering pad 103. In other words, by designing the number of connecting portions 124 arranged at intervals along one of the upper side 103a and the lower side 103b to be 1 to 6, the risk of breakage of the fine grid 101 and the main grid 102 can be significantly reduced, the degree of bending of the welding strip 105 can be significantly reduced, and the total layout area occupied by the first insulating strip 104 on the battery cell body 100 due to designing too many connecting portions 124 can be avoided.

[0085] It should be noted that Figure 1 and Figure 5 In the figure, the number of connecting parts 124 included in a single connecting group 154 ​​is taken as two examples. In actual applications, the number of connecting parts included in a single connecting group can also be 1, 3, 4 or 5.

[0086] In some cases, the number of the connecting portions 124 arranged at intervals near the upper side 103a and the number of the connecting portions 124 arranged at intervals near the lower side 103b may be equal, which is conducive to making the area of ​​the portion of the solder strip 105 located on the upper side 103a away from the lower side 103b raised by the connecting portion 124 almost consistent with the area of ​​the portion of the solder strip 105 located on the lower side 103b away from the upper side 103a raised by the connecting portion 124, which is more conducive to the gradual change of the bending degree of the auxiliary solder strip 105. In an example, the solder pad 103 may have a center line extending in the second direction Y, and the connecting group 154 ​​located on the side of the upper side 103a away from the lower side 103b may be axially symmetrical with the connecting group 154 ​​located on the side of the lower side 103b away from the upper side 103a along the center line.

[0087] It should be noted that, in actual applications, the number of the connecting portions 124 arranged at intervals near the upper side 103 a and the number of the connecting portions 124 arranged at intervals near the lower side 103 b may also be different, and can be adjusted according to specific needs.

[0088] The design of the lengths of the plurality of first insulating strips 104 in a single first insulating group 114 in the second direction Y is described in detail below.

[0089] In some embodiments, reference Figure 7 , Figure 7The fourth partial top view schematic diagram of the back-contact photovoltaic module provided by an embodiment of the present disclosure, the two opposite sides of the pad 103 along the first direction X are respectively the upper side 103a and the lower side 103b, at least two connecting portions 124 are arranged at intervals along one of the upper side 103a and the lower side 103b, and the lengths of the at least two connecting portions 124 in the second direction Y are gradually reduced in the direction away from the pad 103. In other words, the at least two connecting portions 124 arranged at intervals along one of the two opposite sides along the first direction X close to the pad 103 are taken as a group of connecting groups 154, and the lengths of at least two connecting portions 124 in a single connecting group 154 ​​in the second direction Y are gradually reduced in the direction away from the pad 103, that is, the longer the connecting portion 124 is, the smaller the length in the second direction Y is.

[0090] In this way, based on the change in the distance from the pad 103, the soldering ribbon 105 is soldered on the pad 103 (refer to Figure 3 ), the longer the connecting portion 124 away from the pad 103 in the second direction Y is designed to be smaller. This is not only beneficial to reducing the amount of insulating material required to form the connecting portion 124, thereby helping to reduce the preparation cost of the first insulating strip 104 and avoid the warping problem of the back-contact photovoltaic module caused by the volume shrinkage of a large area of ​​insulating material, but also beneficial to lift more areas of the welding ribbon 105 with the help of multiple connecting portions 124 located on the upper side 103a and the lower side 103b of the welding pad 103, so as to reduce the bending degree of the welding ribbon 105 itself and avoid the welding ribbon 105 causing excessive stress on the battery cell body 100.

[0091] In some cases, at least two connecting portions 124 spaced apart along one of the upper side 103a and the lower side 103b are taken as a connecting group 154. In a single connecting group 154, the length of at least two connecting portions 124 in the second direction Y can be gradually reduced from 9 mm to 1 mm along the direction away from the pad 103.

[0092] For any connecting portion 124, if the length of the connecting portion 124 in the second direction Y is less than 1 mm, the length of the connecting portion 124 is relatively short, and the supporting strength of the connecting portion 124 for the welding tape 105 is limited. When the welding tape 105 is placed on the pad 103 and connected, for example, welded to the pad 103, due to the small supporting area of ​​the connecting portion 124 for the welding tape 105, the welding tape 105 is prone to the problem of unstable placement, resulting in relative displacement of the welding tape 105 and the pad 103, and the connecting portion 124 with a shorter length has a smaller buffering effect on the stress, which is prone to cause the local stress of the battery cell body 100 to be larger during welding; if the length of the connecting portion 124 in the second direction Y is greater than 9 mm, the length of the connecting portion 124 is relatively long, then the total layout area of ​​the connecting portion 124 on the battery cell body 100 is relatively large, which will affect the total layout area of ​​the first insulating strip 104 on the battery cell body 100, which is not conducive to reducing the volume of the first insulating strip 104, nor is it conducive to preventing the back-contact photovoltaic module from warping.

[0093] In this way, along the direction away from the pad 103, the lengths of at least two connecting portions 124 in the second direction Y can be gradually reduced from 9 mm to 1 mm, which is beneficial for ensuring that the connecting portion 124 close to the pad 103 has sufficient supporting strength for the welding strip 105 and a good stress buffering effect, so as to effectively avoid the relative offset and stress concentration problems between the welding strip 105 and the pad 103, and at the same time, the connecting portion 124 farther away from the pad 103 has a smaller length in the second direction Y, so as to effectively reduce the layout area occupied by a single connecting group 154 ​​as a whole on the battery cell body 100, so as to prevent serious warping of the back-contact photovoltaic module and reduce the preparation cost required for a single connecting group 154.

[0094] The design of the thickness of the plurality of first insulating strips 104 in a single first insulating group 114 in the third direction Z is described in detail below. The third direction Z is the thickness direction of the battery cell body 100 .

[0095] In some embodiments, reference Figure 8 , Figure 8 Another partial cross-sectional schematic diagram of a back-contact photovoltaic module provided by an embodiment of the present disclosure shows that in the direction away from the pad 103 , the thickness of at least the connecting portion 124 farthest from the pad 103 in the third direction Z gradually decreases.

[0096] In other embodiments, in combination with reference Figure 7 and Fig. 9 , Fig. 9Another partial cross-sectional schematic diagram of a back-contact photovoltaic module provided for an embodiment of the present disclosure, in which at least two connecting portions 124 spaced apart and arranged on one side of two opposite sides along the first direction X close to the pad 103 are grouped as a connecting group 154. In a single connecting group 154, the thickness of at least two connecting portions 124 in the third direction Z gradually decreases along the direction away from the pad 103.

[0097] In the above two embodiments, reference Figure 8 or Fig. 9 , along the direction away from the pad 103, in a single connection group 154, the height of the support point provided by the multiple connection parts 124 to the welding strip 105 is gradually reduced, which is helpful to gradually change the bending degree of the auxiliary welding strip 105, effectively avoiding the phenomenon of excessive bending degree of the local area of ​​the welding strip 105, thereby helping to reduce the bending degree of the welding strip 105 as a whole along the third direction Z, so as to further reduce the risk of the welding strip 105 causing greater stress to the adjacent main grid 102 and fine grid 101 and making them easy to break. In addition, in a single connection group 154, along the direction away from the pad 103, the thickness of at least two connection parts 124 in the third direction Z is gradually reduced, which is also helpful to effectively further reduce the amount of insulating material required for the single connection group 154 ​​as a whole, so as to avoid the warping problem of the back contact photovoltaic module caused by the volume shrinkage of the large area insulating material.

[0098] In some embodiments, reference Fig.10 , Fig.10 The fifth partial top view schematic diagram of the back-contact photovoltaic module provided for an embodiment of the present disclosure, the back-contact photovoltaic module may also include: at least one connecting portion 106 extending along the first direction X, one end of the connecting portion 106 is connected to a fine grid 101 located between the soldering pad 103 and the first insulating strip 104, and the other end of the connecting portion 106 is connected to the soldering pad 103.

[0099] It is worth noting that the fine grid 101 located between the first insulating strip 104 closest to the pad 103 and the pad 103 is most affected by the solder paste 145 in the solder strip 105. Generally speaking, the fine grid 101 will be in contact with the main grid 102 that is in contact with the pad 103, but due to the solder strip 105 (refer to Fig. 9 ) Solder paste 145 (reference Fig. 9), or the influence of the stress applied by the welding ribbon 105 to the cell body 100. Even if the protrusion 134 covers a part of the fine grid 101, the area of ​​the fine grid 101 adjacent to the protrusion 134 and not covered by it may also be at risk of breaking. Based on this, the connection portion 106 is designed to directly electrically connect the fine grid 101, which is most likely to break, to the pad 103. Even if a part of the fine grid 101 cannot transmit the current to the main grid 102 due to the break, the current can be directly transmitted to the pad 103 with the help of the connection portion 106. In other words, the design of the connection portion 106 is conducive to further ensuring that the welding ribbon 105 can collect the current on all fine grids 101 of the same polarity, such as all the first fine grids 111 or all the second fine grids 121, so as to improve the photoelectric conversion efficiency of the back contact photovoltaic module.

[0100] It should be noted that Fig.10 For Figure 7 The structure shown in the figure is provided with a connecting portion 106. In practical applications, Figure 1 , Figure 2 or Figure 5 A connection portion can be provided on the basis of the structures shown.

[0101] In some embodiments, reference Fig.11 , Fig.11 The sixth partial top view schematic diagram of the back-contact photovoltaic module provided by an embodiment of the present disclosure, the back-contact photovoltaic module may also include: a plurality of second insulating strips 107 extending along the second direction Y, a single second insulating strip 107 is located on one of the two opposite sides of the pad 103 along the second direction Y, and covers at least a partial area of ​​one of the two branches of the fine grid 101 disconnected by the pad 103. In other words, for a single pad 103, the opposite-sex fine grids 101 located on the two opposite sides of the pad 103 along the second direction Y, that is, the fine grids 101 electrically insulated from the pad 103, are also designed with second insulating strips 107, and the second insulating strips 107 protect the ends of the two branches of the fine grid 101 disconnected from the pad 103, so that there is also insulating material between the pad 103 and the part of the fine grid 101, further avoiding the contact connection between the welding strip 105 and the fine grid 101 electrically insulated from the pad 103, so as to further avoid the occurrence of short circuit in the back-contact photovoltaic module.

[0102] In some cases, along the second direction Y, the pad 103 is located between two adjacent second insulating strips 107, and the number of fine gates 101 disconnected by the pad 103 can be 2, or 1, 3 or 4. The number of fine gates 101 to be disconnected can be selected according to the actual size of the pad 103.

[0103] In some cases, in conjunction with reference Fig.11 and Fig.12 , Fig.12 A cross-sectional schematic diagram of a second insulating strip in a back-contact photovoltaic module provided in an embodiment of the present disclosure, the second insulating strip 107 includes a first extension portion 117 and a first widened portion 127 close to the pad 103, the first widened portion 127 covers the end of one of the two branches of the fine grid 101 disconnected by the pad 103, the first extension portion 117 is located on a side of the first widened portion 127 away from the pad 103, and along the first direction X, the width of the first widened portion 127 is the fourth width W4, the width of the first extension portion 117 is the fifth width W5, and the fourth width W4 is greater than the fifth width W5. In this way, for any welding strip 105 and the welding pad 103 in contact with the welding strip 105, not only can the first widened portion 127 be used to effectively avoid the welding strip 105 and the fine grid 101 electrically insulated from the welding pad 103 from being in contact with each other, but also the first extended portion 117 having a smaller width than the first widened portion 127 can be used to enhance the protection of the fine grid 101, and the total layout area of ​​the second insulating strip 107 on the battery cell body 100 can be reduced as much as possible, thereby avoiding the warping problem of the back-contact photovoltaic module caused by the volume shrinkage of a large area of ​​insulating material.

[0104] It should be noted that Fig.12 The first extension portion 117 and the first widened portion 127 of the second insulating strip 107 are divided by dotted lines.

[0105] In some embodiments, reference Fig.11 The back-contact photovoltaic module may further include: a plurality of third insulating strips 108 extending along the second direction Y, the third insulating strips 108 being located on a side of the first insulating strip 104 away from the soldering pad 103, and a single third insulating strip 108 only covers at least a partial area of ​​one of the two branches of a thin grid 101 disconnected by the main grid 102. In other words, for a single main grid 102, the opposite thin grids 101 located on the two opposite sides of the main grid 102 along the second direction Y, that is, the thin grids 101 electrically insulated from the main grid 102, are also designed with third insulating strips 108, and the third insulating strips 108 protect the ends of the two branches of the thin grid 101 disconnected from the main grid 102, so that there is also insulating material between the main grid 102 and the part of the thin grid 101, further avoiding the contact connection between the soldering strip 105 and the thin grid 101 electrically insulated from the main grid 102, so as to further avoid the occurrence of short circuit in the back-contact photovoltaic module.

[0106] In some cases, reference Fig.13 , Fig.13A cross-sectional schematic diagram of a third insulating strip in a back-contact photovoltaic module provided for an embodiment of the present disclosure, wherein the third insulating strip 108 includes a second extension portion 118 and a second widened portion 128 close to the main grid 102, the second widened portion 128 covers the end of one of the two branches of the fine grid 101 disconnected by the main grid 102, the second extension portion 118 is located on a side of the second widened portion 128 away from the main grid 102, and along the first direction X, the width of the second widened portion 128 is the sixth width W6, the width of the second extension portion 118 is the seventh width W7, and the sixth width W6 is greater than the seventh width W7. In this way, for any main grid 102 and the pad 103 in contact with the main grid 102, not only can the second widened portion 128 be used to effectively avoid the main grid 102 and the fine grid 101 electrically insulated from the pad 103 from being in contact with each other, but the second extended portion 118 having a smaller width than the second widened portion 128 can also be used to enhance the protection of the fine grid 101, and to minimize the total layout area of ​​the third insulating strip 108 on the battery cell body 100, thereby avoiding the warping problem of the back-contact photovoltaic module caused by the volume shrinkage of a large area of ​​insulating material.

[0107] It should be noted that Fig.13 As indicated by dashed lines, the third insulating strip 108 includes a second extension portion 118 and a second widened portion 128 .

[0108] In some embodiments, along the first direction X, the fourth width W4 of the first widened portion 127 may be smaller than the sixth width W6 of the second widened portion 128. Compared with the second widened portion 128, the first widened portion 127 is closer to the pad 103, and the fourth width W4 of the first widened portion 127 is designed to be smaller, which is not only conducive to preventing the second insulating strip 107 from overflowing to the pad 103, but also conducive to reducing the total layout area of ​​the second insulating strip 107 on the battery cell body 100.

[0109] In some embodiments, along the second direction Y, the length of the first widened portion 127 may be less than the length of the second widened portion 128. Compared with the second widened portion 128, the first widened portion 127 is closer to the pad 103. Designing the length of the first widened portion 127 to be smaller is also beneficial to prevent the second insulating strip 107 from overflowing to the pad 103, and is also beneficial to reducing the total layout area of ​​the second insulating strip 107 on the battery cell body 100.

[0110] In some embodiments, reference Fig.14 , Fig.14A partial top view schematic diagram of the insulating strips and the fine grids in the back-contact photovoltaic module provided by an embodiment of the present disclosure, wherein the spacing between two adjacent second insulating strips 107 along the second direction Y is a first spacing D1, and the spacing between two adjacent third insulating strips 108 along the second direction Y is a second spacing D2, and the first spacing D1 is greater than the second spacing D2. In this way, compared with the extension length of the fine grid 101 disconnected by the pad 103 in the second direction Y, the extension length of the fine grid 101 disconnected by the main grid 102 in the second direction Y can be increased as much as possible under the protection of the third insulating strip 108, so that the photogenerated carriers on more areas of the cell body 10 can be effectively collected by the fine grid 101, and finally collected by the welding strip 105, thereby further improving the photoelectric conversion efficiency of the back-contact photovoltaic module.

[0111] It should be noted that Fig.14 The insulating strips in the embodiment include but are not limited to the first insulating strip 104, the second insulating strip 107 and the third insulating strip.

[0112] In some examples, the first distance D1 may be 1.3 mm, and the second distance D2 may be 0.42 mm.

[0113] In some examples, there are multiple fine gates 101 disconnected by the main grid 102 along the first direction X, wherein the fine gates 101 on opposite sides of the pad 103 along the first direction X are protected by the first insulating strip 104, and the fine gates 101 away from the first insulating group 114 are protected by the third insulating strip 108, and two adjacent third insulating strips 108 located on both sides of the main grid 102 along the second direction Y are taken as a group of third insulating groups, and multiple third insulating groups can be arranged at intervals along the first direction X, and the second spacing D2 between two adjacent third insulating strips 108 in the multiple third insulating groups can be gradually increased to further reduce the total layout area of ​​the third insulating strips 108 on the battery cell body 100.

[0114] In some embodiments, the cell body 100 is a BC cell (Back Contact), which includes but is not limited to an IBC cell (Interdigitated Back Contact), an HBC cell (Heterojunction Back Contact), a TBC cell (TOPCon Back Contact), or an HPBC cell (Hybrid Passivated Back Contact). In addition, the cell body 100 may be a whole cell or a sliced ​​cell, wherein a sliced ​​cell refers to a cell formed by a complete whole cell through a cutting process.

[0115] In some embodiments, the back contact photovoltaic module further includes: an encapsulation layer, the encapsulation layer covers the surface of the cell body 100, and the material of the encapsulation layer can be an organic encapsulation film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyethylene octene co-elastic (POE) film or polyethylene terephthalate (PET) film. Alternatively, the encapsulation layer can also be an EP film, an EPE film or a PVP film, wherein the EP film refers to a co-extruded film composed of stacked EVA film and POE film, the EPE film refers to a co-extruded film formed by stacked EVA film + POE film + EVA film, and the PVP film refers to a co-extruded film formed by stacked POE film + EVA film + POE film. The co-extruded film can be prepared by sequentially extruding one or more raw materials onto another film that has been prepared during the film processing process, or bonding different types of films that have been prepared to each other.

[0116] In some embodiments, the back contact photovoltaic module further comprises: a cover plate, which is located on the surface of the encapsulation layer away from the cell body 100, and the cover plate can be a glass cover plate, a plastic cover plate, or other light-transmitting and non-destructive cover plate. In some embodiments, the surface of the cover plate facing the encapsulation layer can be a concave-convex surface or a velvet surface including multiple convex structures, thereby increasing the utilization rate of incident light.

[0117] In summary, the first insulating strip 104 is designed to include the connecting portion 124, which can not only ensure that the welding strip 105 subsequently connected to the welding pad 103 will not contact the end of the disconnected portion of the heterogeneous fine grid, thereby avoiding the short circuit problem between the first fine grid 111 and the second fine grid 121, but also provide a higher support point for the welding strip 105, so that the welding strip 105 is supported by the welding pad 103 and the connecting portion 124 along the second direction Y, which is conducive to increasing the portion of the welding strip 105 that is raised as a whole. In this way, on the one hand, it is conducive to avoiding excessive bending of the welding strip 105 itself locally; on the other hand, it is conducive to reducing the risk of the welding strip causing greater stress to the adjacent main grid 102 and the fine grid 101, thereby making them easy to break; on the other hand, the connecting portion 124 covers the main grid 102, which is conducive to avoiding the risk of the raw materials of the welding strip 105 melting and dripping down onto the main grid 102 under high temperature conditions, thereby avoiding the phenomenon of the main grid 102 being broken caused by the raw materials of the welding strip 105 melting under high temperature conditions, thereby further reducing the risk of the main grid 102 breaking. Moreover, at least one first insulating strip 104 near the pad 103 is designed to include a protruding portion 134 protruding toward the pad 103, and the protruding portion 134 covers a partial area of ​​a thin grid 101 located between the pad 103 and the first insulating strip 104, which can effectively prevent the thin grid 101 from breaking. Therefore, under the multi-faceted effects of the first insulating strip 104, it is not only helpful to effectively reduce the risk of breaking the thin grid 101 or the main grid 102, but also helpful to reduce the bending degree of the welding strip 105 itself, so as to reduce the stress generated by the welding strip 105 on the battery cell body 100, thereby effectively improving the structural stability of the back contact photovoltaic module.

[0118] Those skilled in the art can understand that the above-mentioned embodiments are specific examples for implementing the present disclosure, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of the embodiments of the present disclosure. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of the present disclosure, so the protection scope of the embodiments of the present disclosure shall be based on the scope defined in the claims.

Claims

1. A back contact photovoltaic module, characterized in that: include: A battery cell body, wherein the back side of the battery cell body is provided with first fine grids and second fine grids alternately arranged along a first direction, and first main grids and second main grids alternately arranged along a second direction, wherein the first fine grids are disconnected at the second main grids, and the second fine grids are disconnected at the first main grids; A plurality of pads, wherein a single pad is located at a disconnection of the first fine grid and connected to the second main grid, or is located at a disconnection of the second fine grid and connected to the first main grid; a plurality of first insulating strips extending along the second direction, at least two of the first insulating strips forming a first insulating group, The first insulation group corresponds to the pads one by one; In a single first insulation group, at least two first insulation strips are respectively located on two opposite sides of the pad along the first direction, and any first insulation strip comprises at least a connecting portion, the connecting portion covers a partial area of ​​a main grid connected to the pad, and covers two ends of two branches of a fine grid disconnected by the main grid, the main grid is one of the first main grid and the second main grid, and the fine grid is one of the first fine grid and the second fine grid; Wherein, at least one of the first insulating strips close to the pad further includes a protruding portion protruding toward the pad, and the protruding portion covers a partial area of ​​one of the fine grids located between the pad and the first insulating strip.

2. The back contact photovoltaic module according to claim 1, characterized in that: Also includes: A plurality of welding strips are arranged at intervals along the second direction, and one of the welding strips is located on one of the main grids, and the welding strip is connected to at least the welding pad; the raised portion also covers a partial area of ​​the main grid connected to the welding pad, and the plane formed by the first direction and the second direction is used as a reference plane. Among the raised portions and the welding strips corresponding to the same main grid, the orthographic projection of the raised portion on the reference plane overlaps with the orthographic projection of the welding strip on the reference plane.

3. The back contact photovoltaic module according to claim 1 or 2, characterized in that: Along the second direction, the length of the protruding portion is a first length, the length of the connecting portion is a second length, and the ratio of the first length to the second length is 1 / 5 to 1 / 2.

4. The back contact photovoltaic module according to claim 1 or 2, characterized in that: Along the first direction, the width of the protruding portion is a first width, the width of the connecting portion is a second width, and the ratio of the first width to the second width is 1 / 2 to 1 / 1.

5. The back contact photovoltaic module according to claim 1 or 2, characterized in that: Two opposite sides of the pad along the first direction are an upper side and a lower side respectively, and one of the first insulating strips closest to the upper side and / or the lower side comprises the connecting portion and the protruding portion; Wherein, along the first direction, the distance between the pad and the protruding portion is greater than or equal to 0.20 mm.

6. The back contact photovoltaic module according to claim 1 or 2, characterized in that: Any of the first insulating strips at least comprises the connecting portion and at least one extending portion, wherein the single extending portion connects one of two opposite ends of the connecting portion along the second direction; Wherein, along the first direction, the width of the connecting portion is a second width, the width of the extending portion is a third width, and the second width is greater than the third width.

7. The back contact photovoltaic module according to claim 1 or 2, characterized in that: The two opposite sides of the pad along the first direction are an upper side and a lower side respectively, at least two of the connecting parts are arranged at intervals close to one of the upper side and the lower side, and along the direction away from the pad, the lengths of at least two of the connecting parts in the second direction decrease successively.

8. The back contact photovoltaic module according to claim 1 or 2, characterized in that: Along the direction away from the pad, at least the thickness of the connecting portion farthest from the pad in the third direction gradually decreases; and / or, At least two of the connecting portions arranged at intervals along one of two sides opposite to each other along the first direction close to the pad are regarded as a connecting group, and in a single connecting group, the thicknesses of at least two of the connecting portions in the third direction gradually decrease along a direction away from the pad; The third direction is the thickness direction of the battery cell body.

9. The back contact photovoltaic module according to claim 1 or 2, characterized in that: Also includes: At least one connecting portion extending along the first direction, one end of the connecting portion is connected to one of the fine grids located between the pad and the first insulating strip, and the other end of the connecting portion is connected to the pad.

10. The back contact photovoltaic module according to claim 1 or 2, characterized in that: Also includes: a plurality of second insulating strips extending along the second direction, a single second insulating strip being located on one side of two opposite sides of the pad along the second direction and covering at least a portion of one of the two branches of the fine grid disconnected by the pad; and / or, A plurality of third insulating strips extending along the second direction, the third insulating strips are located on a side of the first insulating strip away from the pad, and a single third insulating strip only covers at least a partial area of ​​one of the two branches of the fine gate disconnected by the main gate.

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