Back contact photovoltaic modules

Abstract

This disclosure relates to the photovoltaic field and provides a back-contact photovoltaic module, including: a cell body with first and second fine grids alternately arranged along a first direction and first and second main grids alternately arranged along a second direction on the back side; a plurality of pads, each pad being located at a break in the first fine grid and connected to the second main grid or located at a break in 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 corresponding to a pad; at least two of the first insulating strips in a single first insulating group being located on opposite sides of the pad along the first direction, and each first insulating strip including a connecting portion covering a portion of the main grid and the ends of two branches of a fine grid broken by the main grid; at least one first insulating strip including a protrusion protruding toward the pad to cover a portion of the fine grid near the pad, which at least helps to improve the structural stability of the back-contact photovoltaic module.

Description

Technical Field

[0001] This disclosure relates to the photovoltaic field, and in particular to a back-contact photovoltaic module. Background Technology

[0002] Currently, with the gradual depletion of fossil fuels, photovoltaic (PV) cells are becoming increasingly widely used as a new energy alternative. A PV cell is a device that converts solar energy into electrical energy. PV cells utilize the photovoltaic principle to generate charge carriers, which are then extracted using electrodes, thus facilitating the efficient use of electrical energy. The grid lines of a PV cell play a crucial role in collecting and transporting electrons. When assembling multiple PV cells into a PV module, solder ribbons are often used to connect the grid lines of adjacent cells.

[0003] In back-contact photovoltaic modules, the main grid collects current from the fine grid. Pads are provided on the main grid, and solder ribbons connect to the main grid via these pads to collect current. Since the solder ribbons and fine grids are positioned in opposite directions, the solder ribbons must connect to fine grids of the same polarity while also crossing fine grids of different polarities. To prevent short circuits caused by the solder ribbons connecting fine grids of different polarities, insulating strips are designed on the fine grids of the opposite polarity to the solder ribbons.

[0004] However, the design of the insulating strip not only affects the stress on the cell caused by the connection between the solder ribbon and the pad, but also affects the conductivity of the grid near the pad. For example, it can cause excessive bending of the solder ribbon, severe cell warping, or grid breakage in some main grids or grids, thus affecting the structural stability of the back contact photovoltaic module. Summary of the Invention

[0005] This disclosure provides a back-contact photovoltaic module, which at least helps to improve the structural stability of the back-contact photovoltaic module.

[0006] According to some embodiments of this disclosure, one aspect of this disclosure provides a back-contact photovoltaic module, including: a cell body, the back of which is provided with alternating first and second fine grids along a first direction, and alternating first and second main grids 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, each pad being located at a disconnection of the first fine grid and connected to the second main grid, or 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, wherein at least two first insulating strips form a first insulating group, and the first insulating group is connected to the pads. One-to-one correspondence; in a single first insulating group, at least two first insulating strips are respectively located on opposite sides of the pad along the first direction, and each first insulating strip includes at least a connecting portion, the connecting portion covering a portion of the main gate connected to the pad, and covering the two ends of two branches of a fine gate disconnected by the main gate, the main gate being one of the first main gate and the second main gate, and the fine gate being one of the first fine gate and the second fine gate; wherein, at least one of the first insulating strips near the pad also includes a protrusion protruding toward the pad, and the protrusion covering a portion of the fine gate located between the pad and the first insulating strip.

[0007] In some embodiments, the back-contact photovoltaic module further includes: a plurality of solder strips spaced apart along the second direction, with one solder strip located on one main grid, the solder strip being connected to at least the pad; the protrusion also covers a portion of the main grid connected to the pad, and with the plane formed by the first direction and the second direction as a reference plane, the orthographic projection of the protrusion on the reference plane and the orthographic projection of the solder strip on the reference plane overlap with the orthographic projection of the solder strip on the reference plane corresponding to the same main grid.

[0008] In some embodiments, along the second direction, the length of the protrusion 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 protrusion 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 pads have an upper side and a lower side on opposite sides along the first direction, and the first insulating strip closest to the upper side and / or the lower side includes the connecting portion and the protrusion; wherein, along the first direction, the distance between the pads and the protrusion is greater than or equal to 0.20 mm.

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

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

[0013] In some embodiments, along the direction away from the pad, the thickness of at least the connecting portion furthest from the pad gradually decreases in the third direction; and / or, at least two connecting portions spaced apart along one of the opposite sides near the pad in the first direction are grouped into a connecting group, and in a single connecting group, the thickness of at least two connecting portions in the third direction decreases successively along the direction away from the pad; the third direction is the thickness direction of the cell body.

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

[0015] In some embodiments, the back-contact photovoltaic module further includes: a plurality of second insulating strips extending along the second direction, each second insulating strip being located on one side of 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, each third insulating strip being located on the side of the first insulating strip away from the pad, each third insulating strip covering only a portion of one of the two branches of the fine grid disconnected by the main grid.

[0016] The technical solutions provided in this disclosure have at least the following advantages:

[0017] The design of the first insulating strip includes a connecting portion. This not only ensures that the solder ribbon connected to the pad does not contact the broken end of the irregular fine gate, avoiding short circuits between the first and second fine gates, but also provides a higher support point for the solder ribbon. The solder ribbon is supported by both the pad and the connecting portion along the second direction, increasing the overall height of the solder ribbon. This helps to prevent excessive local bending of the solder ribbon and reduces the risk of excessive stress on the adjacent main gate and fine gates, making them prone to breakage. Furthermore, the connecting portion covering the main gate helps to prevent the raw material from the solder ribbon from molten and dripping onto the main gate at high temperatures, thus preventing gate breakage caused by the molten material. Moreover, at least one of the first insulating strips near the pad includes a protrusion facing the pad, covering a portion of a fine gate located between the pad and the first insulating strip, effectively preventing breakage of the fine gate at this location.

[0018] In summary, the first insulating strip, through its multiple functions, not only helps to effectively reduce the risk of breakage of the fine grid or main grid, but also helps to reduce the bending degree of the solder strip itself, thereby reducing the stress generated by the solder strip on the cell body and thus effectively improving the structural stability of the back contact photovoltaic module. Attached Figure Description

[0019] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this disclosure or the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a first partial top view of a back-contact photovoltaic module provided in an embodiment of the present disclosure;

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

[0022] Figure 3 This is a second partial top view of a back-contact photovoltaic module provided in an embodiment of the present disclosure;

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

[0024] Figure 5 This is a third partial top view of a back-contact photovoltaic module provided in an embodiment of the present disclosure;

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

[0026] Figure 7 This is a fourth partial top view of a back-contact photovoltaic module provided in an embodiment of the present disclosure;

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

[0028] Figure 9 This is another partial cross-sectional schematic diagram of a back-contact photovoltaic module provided in an embodiment of the present disclosure;

[0029] Figure 10 This is a fifth partial top view of a back-contact photovoltaic module provided in an embodiment of the present disclosure;

[0030] Figure 11 This is a sixth partial top view of a back-contact photovoltaic module provided in an embodiment of the present disclosure;

[0031] Figure 12 This is a cross-sectional schematic diagram of a second insulating strip in a back-contact photovoltaic module according to an embodiment of the present disclosure;

[0032] Figure 13 This is a cross-sectional schematic diagram of a third insulating strip in a back-contact photovoltaic module according to an embodiment of the present disclosure;

[0033] Figure 14 This is a partial top view of an embodiment of the present disclosure of an insulating strip and a fine grid in a back-contact photovoltaic module. Detailed Implementation

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

[0035] This disclosure provides a back-contact photovoltaic module. The first insulating strip is designed with a connecting portion. This design not only ensures that the solder ribbon, which is subsequently connected to the pad, does not contact the end of the discontinuous fine grid, thus avoiding short circuits between the first and second fine grids, but also provides a higher support point for the solder ribbon. The solder ribbon is supported by both the pad and the connecting portion along the second direction, increasing the overall height of the solder ribbon. This helps to prevent excessive local bending of the solder ribbon and reduces the risk of excessive stress on the adjacent main grid and fine grids, making them prone to breakage. Furthermore, the connecting portion covering the main grid helps to prevent the raw material from the solder ribbon melting and dripping onto the main grid under high-temperature conditions, thus preventing grid breakage caused by the molten material. Moreover, at least one of the first insulating strips near the pad includes a protrusion facing the pad, and this protrusion covers a portion of a fine grid located between the pad and the first insulating strip, effectively preventing breakage of the fine grid at this location. Therefore, under the multifaceted effects of the first insulating strip, it not only helps to effectively reduce the risk of breakage of the fine grid or main grid, but also helps to reduce the bending degree of the solder strip itself, so as to reduce the stress generated by the solder strip on the cell body, thereby effectively improving the structural stability of the back contact photovoltaic module.

[0036] In the description of the embodiments of this disclosure, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "a plurality of" means two or more, unless otherwise explicitly defined.

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

[0038] In the description of the embodiments of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

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

[0040] In the description of the embodiments of this disclosure, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.

[0041] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0042] In the accompanying drawings corresponding to the embodiments of this disclosure, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" 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 portion of the edge of the entire surface.

[0043] In the description of embodiments of this disclosure, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. Furthermore, when a component such as a layer, film, region, or plate is described as being "on / located" on another component, it can 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 be present therein. Moreover, 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 indicates that no other components are located therein.

[0044] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0045] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this disclosure to facilitate a better understanding of the embodiments. However, the technical solutions claimed in the embodiments of this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0046] This disclosure provides an embodiment of a back-contact photovoltaic module. The following will describe the back-contact photovoltaic module provided in this disclosure in detail with reference to the accompanying drawings.

[0047] Reference Figures 1 to 3The back-contact photovoltaic module includes: a cell body 100, the back side 100a of which is provided with alternating first fine grids 111 and second fine grids 121 along a first direction X, and alternating first main grids 112 and second main grids 122 along a second direction Y, wherein the first fine grids 111 are interrupted at the second main grids 122, and the second fine grids 121 are interrupted at the first main grids 112; a plurality of pads 103, each pad 103 being located at the interruption point of the first fine grid 111 and connected to the second main grid 122, or located at the interruption point 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, wherein at least two first insulating strips 104 form a group of first insulating groups 114, and the first insulating groups 114 correspond one-to-one with the pads 103; a single In the first insulating group 114, at least two first insulating strips 104 are respectively located on opposite sides of the pad 103 along the first direction X, and each first insulating strip 104 includes at least a connecting portion 124, which covers a portion of the main gate 102 connected to the pad 103, and covers the two ends of two branches of a fine gate 101 that is disconnected by the main gate 102. The main gate 102 is one of the first main gate 112 and the second main gate 122, and the fine gate 101 is one of the first fine gate 111 and the second fine gate 121. At least one of the first insulating strips 104 near the pad 103 also includes a protrusion 134 that protrudes toward the pad 103, and the protrusion 134 covers a portion of the fine gate 101 located between the pad 103 and the first insulating strip 104.

[0048] It is worth noting that, based on the different polarities, the fine gate 101 can be divided into two types: a first fine gate 111 and a second fine gate 121. Similarly, the main gate 102 can be divided into two types: a first main gate 112 and a second main gate 122. The first main gate 112 is used to collect the current from all the first fine gates 111, and the second main gate 122 is used to collect the current from all the second fine gates 121. Based on this, the multiple 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 break point of the second fine gate 121 and is connected to the first main gate 112. The second pad 123 is located at the break point of the first fine gate 111 and is connected to the second main gate 122. Specifically, the break point of the second fine gate 121 allows the first main gate 112 to extend along the first direction X and be electrically connected to the multiple first fine gates 111. The break point of the first fine gate 111 allows the second main gate 122 to extend along the first direction X and be electrically connected to the multiple second fine gates 121.

[0049] Furthermore, based on the different types of the connected pads 103, the solder ribbons 105 described below can also be divided into two types: a first solder ribbon 115 and a second solder ribbon 125. The first solder ribbon 115 is in contact with the first pad 113 to collect the current on the first main gate 112, and the second solder ribbon 125 is in contact with the second pad 123 to collect the current on the second main gate 122.

[0050] It should be noted that, Figure 1 This is a first partial top view of a back-contact photovoltaic module according to an embodiment of the present disclosure. Figure 2 This is a partial cross-sectional schematic diagram of a back-contact photovoltaic module provided in an embodiment of the present disclosure. Figure 3 This is a second partial top view of a back-contact photovoltaic module according to 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 The first fine grid 111 is indicated by a thicker solid line, and the second fine grid 121 is indicated by a thicker dashed line. Figure 1 The first insulating strip 104 is drawn using a perspective drawing method. Furthermore, just as fine gate 101 generally refers to one of the first fine gate 111 and the second fine gate 121, and main gate 102 generally refers to one of the first main gate 112 and the second main gate 122, pad 103 described in subsequent paragraphs may generally refer to one of the first pad 113 or the second pad 123, and solder ribbon 105 may generally refer to one of the first solder ribbon 115 or the second solder ribbon 125.

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

[0052] It is worth noting that in the back-contact photovoltaic module provided in one embodiment of this disclosure, the insulating strips around the pad 103 are specially designed. Specifically, a first insulating group 114 is designed to correspond one-to-one with the pad 103. In a single first insulating group 114, at least two first insulating strips 104 are respectively located on opposite sides of the pad 103 along the first direction X. That is, at least one first insulating strip 104 is provided on both opposite sides of the pad 103 along the first direction X. Moreover, each first insulating strip 104 includes at least a connecting portion 124. The connecting portion 124 not only covers a part of the main grid 102 connected to the pad 103, but also covers the two ends of the two branches of a thin grid 101 that is disconnected by the main grid 102. In other words, near the pad 103, the break point of the thin grid 101 that is disconnected by the main grid 102 that is electrically connected to the pad 103 is also covered by the first insulating strip 104.

[0053] Thus, the connecting portion 124 not only ensures that the solder ribbon 105, which is subsequently connected to the pad 103, will not come into contact with the end of the disconnection of the anisotropic fine gate, thus avoiding short circuit between the first fine gate 111 and the second fine gate 121, but also provides a higher support point for the solder ribbon 105.

[0054] In some cases, in conjunction with references Figure 2 and Figure 3 The solder ribbon 105 includes a solder ribbon body 135 and solder paste 145. When the solder ribbon 105 is connected, for example, soldered to the pad 103, the solder paste 145 in the solder ribbon 105 makes the solder ribbon body 135 and the pad 103 electrically connected. However, along the third direction Z, the pad 103 overlaps the main gate 102, and based on the solder paste 145 in the solder ribbon 105, there is a certain height difference between the solder ribbon 105 and the main gate 102. The design of the connecting part 124 also overlaps the main gate 102, which allows more areas of the subsequently formed solder ribbon 105 along the second direction Y to be supported by higher support points. In other words, not only is the part of the solder ribbon body 135 in the solder ribbon 105 that contacts and connects with the pad 103 raised, but the part that contacts and connects with the connecting part 124 is also raised, which helps to increase the overall raised part of the solder ribbon body 135. Thus, on the one hand, it helps to avoid excessive local bending of the solder ribbon body 135 itself. That is, from the perspective of the entire solder ribbon 105, the degree of bending of the solder ribbon body 135 per unit length is reduced, and it is not only the solder ribbon body 135 at the contact and connection with the solder pad 103 that is raised. In other words, it helps to slow down the bending trend of the solder ribbon body 135. On the other hand, avoiding excessive local bending of the solder ribbon body 135 itself helps to reduce the risk of the solder ribbon 105 causing large stress on the adjacent main grid 102 and fine grid 101, making them prone to breakage. Furthermore, the connecting portion 124 covering the main grid 102 helps to avoid the risk of the raw material of the solder ribbon 105 melting and dripping down onto the main grid 102 under high temperature conditions, and avoids the main grid 102 being broken due to the raw material of the solder ribbon 105 melting under high temperature conditions, thereby further reducing the risk of the main grid 102 breaking. Here, the third direction Z is the thickness direction of the cell body 100. It is worth emphasizing that the degree of bending of the solder strip 105 described in the following paragraphs mainly refers to the degree of bending of the solder strip body 135 within the solder strip 105.

[0055] Furthermore, the design of at least one first insulating strip 104 near the pad 103 includes a protrusion 134 that protrudes toward the pad 103, and the protrusion 134 covers a portion of a fine gate 101 located between the pad 103 and the first insulating strip 104. In other words, the protrusion 134 covers a portion of a fine gate 101 that is adjacent to and electrically connected to the pad 103. Since the fine gate 101 is closest to the pad 103, when the solder ribbon 105 is contacted and connected, for example, when soldered to the pad 103, the portion of the solder ribbon 105 located directly above the fine gate 101 is also subject to greater temperature influence. Designing the protrusion 134 to cover the fine gate 101 in this area can effectively prevent the fine gate 101 from breaking.

[0056] In summary, the first insulating strip 104 not only helps to effectively reduce the risk of breakage of the fine grid 101 or the main grid 102, but also helps to reduce the bending degree of the solder ribbon 105 itself, thereby reducing the stress generated by the solder ribbon 105 on the cell body 100, thus 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 covers only one non-linear fine grid 101 that is interrupted by the main grid 102. Moreover, the first insulating strip 104 is designed on only a portion of the fine grids 101 near the pad 103 along the first direction X. In this way, compared to laying a large area of ​​insulating material around the pad, it is beneficial to ensure that the first insulating strip 104 covers as much as possible the areas on the main grid 102 and the fine grid 101 that are prone to breakage, thereby reducing the risk of breakage of the main grid 102 and the fine grid 101, and reducing the degree of bending of the solder ribbon 105 that is subsequently electrically connected to the pad 103. At the same time, it reduces the total layout area occupied by the first insulating strip 104 on the cell body 100, thereby reducing the amount of insulating material required to form the first insulating strip 104. This helps to reduce the manufacturing 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] Furthermore, each first insulating strip 104 includes a connecting portion 124, but only a portion of the first insulating strips 104 also include a protrusion 134. For example, only the first insulating strip 104 closest to the pad 103 along the first direction X includes a protrusion 134. In a single first insulating group 114, only two first insulating strips 104 include a protrusion 134 and are located on opposite sides of the pad 103 along the first direction X. In this way, the risk of breakage of the fine grid 101 closest to the pad 103 can be effectively reduced, and the total layout area of ​​the first insulating strips 104 on the cell body 100 can be minimized as much as possible.

[0059] The embodiments of this disclosure will now be described in more detail 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 further include: a plurality of solder strips 105 arranged at intervals along the second direction Y, wherein one solder strip 105 is located on a main grid 102, and the solder strip 105 is at least connected to the pad 103; the protrusion 134 also covers a portion of the main grid 102 connected to the pad 103, and with the plane formed by the first direction X and the second direction Y as the reference plane, among the protrusion 134 and solder strip 105 corresponding to the same main grid 102, the orthographic projection of the protrusion 134 on the reference plane overlaps with the orthographic projection of the solder strip 105 on the reference plane.

[0061] It is worth noting that when the solder ribbon 105 is made into contact, for example, soldered to the pad 103, not only is the fine grid 101 closer to the pad 103 susceptible to the influence of the raw material molten by the solder ribbon 105 under high temperature conditions, but the main grid 102 closer to the pad 103 is also susceptible to the influence of the raw material molten by the solder ribbon 105 under high temperature conditions. Therefore, the protrusion 134 is designed to cover not only a portion of the fine grid 101 closest to and electrically connected to the pad 103, but also a portion of the main grid 102 connected to the pad 103. This design allows the protrusion 134 to simultaneously protect the easily broken portions of both the main grid 102 and the fine grid 101, thereby further improving the structural stability of the back-contact photovoltaic module.

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

[0063] It should be noted that the overlap between the orthographic projection of the protrusion 134 on the reference plane and the orthographic projection of the solder strip 105 on the reference plane includes at least the following situations: In some cases, the orthographic projection of the protrusion 134 on the reference plane is located within the orthographic projection of the solder strip 105 on the reference plane; in other cases, the orthographic projection of the solder strip 105 on the reference plane is located within the orthographic projection of the protrusion 134 on the reference plane; and in still other cases, the orthographic projection of the protrusion 134 on the reference plane and the orthographic projection of the solder strip 105 on the reference plane only partially overlap.

[0064] In some embodiments, reference Figure 4 , Figure 4This is a top view of a first insulating strip in a back-contact photovoltaic module according to an embodiment of the present disclosure. Along the second direction Y, the length of the protrusion 134 is the first length L1, and the length of the connecting portion 124 is the second length L2. 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] 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 protective 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 cell body 100 is large, which will affect the total layout area of ​​the first insulating strip 104 on the cell body 100, which is not conducive to reducing the volume of the first insulating strip 104, nor is it conducive to preventing warping of the back contact photovoltaic module. Therefore, 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 protective effect of the protrusion 134 on the fine grid 101, effectively reducing the risk of breakage of the fine grid 101, while reducing the volume of the first insulating strip 104 to prevent severe warping of the back contact photovoltaic module.

[0066] It should be noted that, Figure 4 The first insulating strip 104 is divided into a raised portion 134 and a connecting portion 124 by a dashed line.

[0067] In some examples, along the second direction Y, the first length L1 of the protrusion 134 can be greater than or equal to 0.20 mm. For example, the first length L1 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., to ensure that the protrusion 134 provides good protection for the fine grid 101.

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

[0069] Reference Figure 1 and Figure 4 If the second length L2 is less than 1 mm, then the length of the connecting portion 124 is shorter, and the connecting portion 124 is welded to the strip 105 (reference). Figure 3The supporting strength of the connecting part 124 is limited. When the solder ribbon 105 is placed on the solder pad 103 and connected, for example, when soldering to the solder pad 103, the solder ribbon 105 is prone to uneven placement, such as tilting, due to the small supporting area of ​​the connecting part 124 for the solder ribbon 105. This leads to the relative offset between the solder ribbon 105 and the solder pad 103. Moreover, the short length of the connecting part 124 has a small buffering effect on the force, which can easily cause a large local force on the cell body 100 during welding. If the second length L2 is greater than 9mm, the length of the connecting part 124 is longer, and the total layout area of ​​the connecting part 124 on the cell body 100 is larger. This will affect the total layout area of ​​the first insulating strip 104 on the 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. Thus, the second length L2 can be designed to be 1mm to 9mm, which is beneficial to ensure that the connecting part 124 has sufficient support strength for the solder strip 105 and a good stress buffering effect, so as to effectively avoid the relative offset and stress concentration problems between the solder strip 105 and the solder pad 103, while reducing the volume of the first insulating strip 104 to prevent severe warping of the back contact photovoltaic module.

[0070] It should be noted that, along the second direction Y, the ratio of the length of the protrusion 134 to the length of the connecting portion 124 in different first insulating strips 104 can be the same or different; the lengths of different protrusions 134 in different first insulating strips 104 can be the same or different; and the lengths of different connecting portions 124 in different first insulating strips 104 can 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 the first width W1, and the width of the connecting portion 124 is the 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, in conjunction with references Figure 1 and Figure 4In the same first insulating strip 104, the ratio of the first width W1 and the second width W2 symbolizes 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 protrudes less than the connecting portion 124. The portion of the protrusion 134 located between the pad 103 and the fine gate 101 closest to the pad 103 has a smaller width, and this portion of the protrusion 134 is at the edge of the first insulating strip 104. The edge is prone to thinning due to adhesive overflow, affecting the thickness of the protrusion 134 around the fine gate 101, thus affecting the protective effect of the protrusion 134 on the fine gate 101. If the ratio of the first width W1 to the second width W2 is greater than 1 / 1, the protrusion 134 protrudes more than the connecting portion 124. The distance between the protrusion 134 and the pad 103 is smaller, and the insulating material constituting the protrusion 134, such as insulating adhesive, is prone to overflow onto the pad 103. Solder ribbon 105 is then soldered onto the pad 103 (see reference). Figure 3 When soldering, the raw materials of solder ribbon 105, such as solder paste, are easily split in two by the insulating adhesive that overflows onto the pad 103, resulting in poor contact between solder ribbon 105 and pad 103.

[0073] Thus, the ratio of the first width W1 to the second width W2 can be 1 / 2 to 1 / 1, which helps to ensure that the thickness of the protrusion 134 around the fine gate 101 is not too thin, so as to ensure that the protrusion 134 provides good protection for the fine gate 101. It also helps to ensure that there is a suitable distance between the protrusion 134 and the pad 103, effectively preventing the insulating material constituting the protrusion 134 from overflowing onto the pad 103, so as to avoid poor contact between the solder ribbon 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 to 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 to 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, the ratio of the width of the protrusion 134 to the width of the connecting portion 124 in different first insulating strips 104 can be the same or different; the width of different protrusions 134 in different first insulating strips 104 can be the same or different; and the width of different connecting portions 124 in different first insulating strips 104 can be the same or different.

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

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

[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. This helps to effectively prevent the insulating material constituting the protrusion 134 from overflowing onto the pad 103, thereby avoiding poor contact between the solder ribbon 105 and the pad 103 and improving the structural stability of the back contact photovoltaic module.

[0079] In some embodiments, in conjunction with reference Figure 5 and Figure 6 Each of the first insulating strips 104 includes at least a connecting portion 124 and at least one extension portion 144, wherein the single extension portion 144 connects one of the 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 a second width W2, and the width of the extension portion 144 is a third width W3, wherein the second width W2 is greater than the third width W3.

[0080] It is worth noting that for any first insulating strip 104, regardless of whether it includes the protrusion 134, it includes a connecting portion 124 and at least one extension 144, and only a portion of the first insulating strips 104 include the protrusion 134. Furthermore, designing the third width W3 of the extension 144 to be smaller than the second width W2 of the connecting portion 124 is advantageous in improving the insulation effect of the first insulating strip 104 on the fine grid 101 it covers, while simultaneously reducing the amount of insulating material required to form the extension 144. This reduces the amount of insulating material required to form the first insulating strip 104, thereby reducing the manufacturing cost of the first insulating strip 104 and avoiding the warping problem of the back-contact photovoltaic module caused by the volume shrinkage of a large area of ​​insulating material.

[0081] in, Figure 5 This is a third partial top view of a back-contact photovoltaic module according to an embodiment of the present disclosure. Figure 6 This is another top view schematic diagram of the first insulating strip in a back-contact photovoltaic module provided in 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 repeated here.

[0082] In some cases, continue to refer to Figure 5 and Figure 6 Each first insulating strip 104 includes a connecting portion 124 and two extensions 144, the two extensions 144 respectively connecting opposite ends of the connecting portion 124 along the second direction Y, to improve the integrity and symmetry of the insulation effect of the first insulating strip 104 on the fine grid 101 it covers. In other cases, any first insulating strip may also include a connecting portion and an extension, the extension connecting one end of opposite ends of the connecting portion along the second direction.

[0083] In some embodiments, reference Figure 1 or Figure 5 The pad 103 has an upper side 103a and a lower side 103b on opposite sides along the first direction X. The number of 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 opposite sides of the pad 103 along the first direction X are considered as a group of connecting portions 154. The number of connecting portions 124, i.e., the first insulating strips 104, in a single connecting portion group 154 ​​is 1 to 6. Therefore, the number of connecting portions 124, i.e., the first insulating strips 104, in a single first insulating group 114 is 2 to 12.

[0084] It is worth noting that during the soldering of the solder ribbon 105 on the pad 103, the portion of the solder ribbon 105 located near the pad 103 is significantly affected by temperature. By covering the main gate 102 directly opposite to the portion of the solder ribbon 105 that is significantly affected by temperature along the third direction Z and the anisotropic fine gate 101 that is insulated relative to the main gate 102, the risk of breakage of the fine gate 101 and the main gate 102 can be significantly reduced, and the degree of bending of the solder ribbon 105 caused by the height difference between the pad 103 and the main gate 102 can be significantly mitigated. It is not necessary to design a first insulating strip 104 including the connecting portion 124 in the area away from the 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 solder ribbon 105 can be significantly reduced, and the design of too many connecting portions 124 can be avoided, which would increase the total layout area of ​​the first insulating strip 104 on the cell body 100.

[0085] It should be noted that, Figure 1 and Figure 5 The example only uses the number of connected parts 124 contained in a single connected group 154 ​​as two examples. In actual applications, the number of connected parts contained in a single connected group can also be 1, 3, 4 or 5, etc.

[0086] In some cases, the number of connecting portions 124 spaced apart near the upper side 103a can be equal to the number of connecting portions 124 spaced apart near the lower side 103b. This is beneficial because the area of ​​the solder ribbon 105 located on the upper side 103a away from the lower side 103b that is raised by the connecting portions 124 is almost the same as the area of ​​the solder ribbon 105 located on the lower side 103b away from the upper side 103a that is raised by the connecting portions 124. This is more conducive to the gradual change in the curvature of the solder ribbon 105. In one example, the solder pad 103 may have a centerline extending along 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 about the centerline with the connecting group 154 ​​located on the side of the lower side 103b away from the upper side 103a.

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

[0088] The following provides a detailed description of the design of the lengths of the multiple first insulating strips 104 in the second direction Y within a single first insulating group 114.

[0089] In some embodiments, reference Figure 7 , Figure 7This is a fourth partial top view of a back-contact photovoltaic module according to an embodiment of the present disclosure. The pad 103 has an upper side 103a and a lower side 103b on opposite sides along the first direction X. At least two connecting portions 124 are arranged at intervals near one of the upper side 103a and the lower side 103b. Furthermore, along the direction away from the pad 103, the lengths of the at least two connecting portions 124 in the second direction Y decrease sequentially. In other words, at least two connecting portions 124 arranged at intervals near one of the opposite sides along the first direction X near the pad 103 are considered as a group of connecting portions 154. Along the direction away from the pad 103, the lengths of the at least two connecting portions 124 in a single group of connecting portions 154 in the second direction Y decrease sequentially, meaning the connecting portions 124 further away from the pad 103 have smaller lengths in the second direction Y.

[0090] Thus, based on the change in distance from pad 103, solder ribbon 105 is soldered onto pad 103 (see reference). Figure 3 The design minimizes the impact of temperature changes on the connection portion 124, which is further away from the pad 103, by making the length of the connection portion 124 in the second direction Y smaller. This not only helps reduce the amount of insulating material required to form the connection portion 124, thereby reducing the manufacturing 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, but also helps to raise more areas of the solder ribbon 105 by using multiple connection portions 124 located on the upper side 103a and lower side 103b of the pad 103, so as to reduce the bending degree of the solder ribbon 105 itself and avoid the solder ribbon 105 causing excessive stress on the cell body 100.

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

[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 solder ribbon 105 is limited. When the solder ribbon 105 is placed on the solder pad 103 and connected, for example, when soldering to the solder pad 103, the solder ribbon 105 is prone to uneven placement due to the small supporting area of ​​the connecting portion 124 for the solder ribbon 105, resulting in relative offset between the solder ribbon 105 and the solder pad 103. Moreover, the shorter length of the connecting portion 124 has a smaller buffering effect on the force, which can easily cause a large local force on the cell body 100 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, and the total layout area of ​​the connecting portion 124 on the cell body 100 is large, which will affect the total layout area of ​​the first insulating strip 104 on the cell body 100. This 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] Thus, along the direction away from the pad 103, the length of at least two connecting portions 124 in the second direction Y can be gradually reduced from 9 mm to 1 mm. This is beneficial in ensuring that the connecting portions 124 near the pad 103 have sufficient support strength for the solder ribbon 105 and a good stress buffering effect, so as to effectively avoid the relative offset and stress concentration problems between the solder ribbon 105 and the pad 103. At the same time, it makes the length of the connecting portions 124 further away from the pad 103 smaller in the second direction Y, so as to effectively reduce the layout area occupied by a single connecting group 154 ​​on the cell body 100, so as to prevent severe warping of the back contact photovoltaic module and reduce the manufacturing cost required for a single connecting group 154.

[0094] The following details the design of the thickness of the multiple first insulating strips 104 in a single first insulating group 114 in the third direction Z, where the third direction Z is the thickness direction of the battery cell body 100.

[0095] In some embodiments, reference Figure 8 , Figure 8 This is another partial cross-sectional view of a back-contact photovoltaic module provided in an embodiment of the present disclosure. Along the direction away from the pad 103, the thickness of the connecting portion 124, at least the portion furthest from the pad 103, gradually decreases in the third direction Z.

[0096] In other embodiments, in conjunction with reference to Figure 7 and Figure 9 , Figure 9This is a partial cross-sectional view of a back-contact photovoltaic module provided in an embodiment of the present disclosure. At least two connecting portions 124 arranged at intervals along one of the opposite sides of the pad 103 in the first direction X are regarded as a group of connecting portions 154. In a single connecting portion 154, the thickness of at least two connecting portions 124 in the third direction Z decreases successively in the direction away from the pad 103.

[0097] In the two embodiments described above, reference is made to Figure 8 or Figure 9 Along the direction away from the pad 103, the height of the support points provided by the multiple connecting portions 124 to the solder ribbon 105 in a single connecting group 154 ​​gradually decreases. This helps to gradually change the bending degree of the solder ribbon 105, effectively avoiding excessive bending in local areas of the solder ribbon 105. This helps to mitigate the overall bending degree of the solder ribbon 105 along the third direction (Z), further reducing the risk of the solder ribbon 105 causing excessive stress on the adjacent main grid 102 and fine grid 101, making them prone to breakage. Furthermore, in a single connecting group 154, along the direction away from the pad 103, the thickness of at least two connecting portions 124 gradually decreases in the third direction (Z). This also helps to effectively reduce the amount of insulating material required for the entire single connecting group 154, avoiding warping problems in the back-contact photovoltaic module caused by the volume shrinkage of large-area insulating material.

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

[0099] It is worth noting that the fine gate 101 located between the first insulating strip 104, which is closest to the pad 103, and the pad 103 is most affected by the solder paste 145 in the solder ribbon 105. Normally, this fine gate 101 would contact the main gate 102, which is connected to the pad 103, but due to the solder ribbon 105 (reference...) Figure 9 Solder paste 145 (reference) Figure 9Due to the influence of the solder ribbon 105 on the cell body 100, even if the protrusion 134 covers a portion of the grid 101, the area of ​​the grid 101 adjacent to the protrusion 134 but not covered by it may still be at risk of breakage. Therefore, the connection portion 106 is designed to directly connect the grid 101 most prone to breakage to the pad 103. Even if a portion of the grid 101 is broken and cannot transmit current to the main grid 102, the connection portion 106 can directly transmit current to the pad 103. In other words, the design of the connection portion 106 helps to further ensure that the solder ribbon 105 can collect current from all grids 101 of the same polarity, such as all first grids 111 or all second grids 121, thereby improving the photoelectric conversion efficiency of the back-contact photovoltaic module.

[0100] It should be noted that, Figure 10 In order to be in Figure 7 The structure shown is equipped with a connecting part 106. In practical applications, in Figure 1 , Figure 2 or Figure 5 Connecting parts can be added to any of the structures shown.

[0101] In some embodiments, reference Figure 11 , Figure 11 This is a sixth partial top view of a back-contact photovoltaic module provided in an embodiment of the present disclosure. The back-contact photovoltaic module may further include: a plurality of second insulating strips 107 extending along the second direction Y. Each second insulating strip 107 is located on one of the opposite sides of the pad 103 along the second direction Y, and covers at least a portion of one of the two branches of the fine grid 101 that is disconnected by the pad 103. In other words, for a single pad 103, the anisotropic fine grid 101 located on the opposite sides of the pad 103 along the second direction Y, that is, the fine grid 101 electrically insulated from the pad 103, is also designed with a second insulating strip 107. The second insulating strip 107 protects the ends of the two branches of the fine grid 101 that is disconnected by the pad 103, so that there is also an insulating material between the pad 103 and the portion of the fine grid 101, further preventing the solder ribbon 105 from contacting and connecting with the fine grid 101 that is electrically insulated from the pad 103, so as to further prevent the occurrence of short circuits 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 that are broken by the pad 103 can be 2, 1, 3 or 4. The number of fine gates 101 that need to be broken can be selected according to the actual size of the pad 103.

[0103] In some cases, in conjunction with references Figure 11 and Figure 12 , Figure 12 This is a cross-sectional schematic diagram of a second insulating strip in a back-contact photovoltaic module according to an embodiment of the present disclosure. The second insulating strip 107 includes a first extension portion 117 and a first widening portion 127 near the pad 103. The first widening portion 127 covers the end of one of the two branches of the fine grid 101 that is broken by the pad 103. The first extension portion 117 is located on the side of the first widening portion 127 away from the pad 103 and along the first direction X. The width of the first widening portion 127 is a fourth width W4, and the width of the first extension portion 117 is a fifth width W5. The fourth width W4 is greater than the fifth width W5. Thus, for any solder strip 105 and the pad 103 in contact with the solder strip 105, the solder strip 105 and the fine grid 101 electrically insulated from the pad 103 can be effectively prevented from contacting each other by means of the first widening portion 127. Furthermore, the protection of the fine grid 101 can be strengthened by means of the first extension portion 117, which is smaller than the first widening portion 127, and the total layout area of ​​the second insulating strip 107 on the 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 the large-area insulating material.

[0104] It should be noted that, Figure 12 The second insulating strip 107 is divided by a dashed line into a first extension portion 117 and a first widening portion 127.

[0105] In some embodiments, reference Figure 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 are located on the side of the first insulating strip 104 away from the pad 103. Each third insulating strip 108 covers at least a portion of one of the two branches of a fine grid 101 that is disconnected by the main grid 102. In other words, for a single main grid 102, the dissimilar fine grids 101 located on opposite sides of the main grid 102 along the second direction Y, i.e., the fine grids 101 electrically insulated from the main grid 102, are also designed with third insulating strips 108. The third insulating strips 108 protect the ends of the two branches of the fine grid 101 that are disconnected from the main grid 102, so that there is also insulating material between the main grid 102 and the portion of the fine grid 101, further preventing the solder strip 105 from contacting and connecting with the fine grid 101 that is electrically insulated from the main grid 102, thereby further preventing the occurrence of short circuits in the back-contact photovoltaic module.

[0106] In some cases, refer to Figure 13 , Figure 13This is a cross-sectional schematic diagram of a third insulating strip in a back-contact photovoltaic module according to an embodiment of the present disclosure. The third insulating strip 108 includes a second extension portion 118 and a second widening portion 128 near the main grid 102. The second widening portion 128 covers the end of one of the two branches of the fine grid 101 that is broken by the main grid 102. The second extension portion 118 is located on the side of the second widening portion 128 away from the main grid 102 and along the first direction X. The width of the second widening portion 128 is a sixth width W6, and the width of the second extension portion 118 is a seventh width W7. The sixth width W6 is greater than the seventh width W7. Thus, for any main grid 102 and the pad 103 that is in contact with the main grid 102, the second widening portion 128 can effectively prevent the main grid 102 and the fine grid 101 that is electrically insulated from the pad 103 from contacting each other. The second extension portion 118, which is smaller than the second widening portion 128, can strengthen the protection of the fine grid 101 and minimize the total layout area of ​​the third insulating strip 108 on the cell body 100, thereby avoiding the warping problem of the back contact photovoltaic module caused by the volume shrinkage of the large-area insulating material.

[0107] It should be noted that, Figure 13 The third insulating strip 108 is divided by a dotted line and includes a second extension portion 118 and a second widening 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 to the second widened portion 128, the first widened portion 127 is closer to the pad 103. Designing the fourth width W4 of the first widened portion 127 to be smaller not only helps to prevent the second insulating strip 107 from overflowing onto the pad 103, but also helps to reduce the total layout area of ​​the second insulating strip 107 on the 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 to 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 also helps to prevent the second insulating strip 107 from overflowing onto the pad 103, and also helps to reduce the total layout area of ​​the second insulating strip 107 on the cell body 100.

[0110] In some embodiments, reference Figure 14 , Figure 14This is a partial top view of an embodiment of a back-contact photovoltaic module provided by this disclosure, showing the relationship between insulating strips and fine grids. The distance between two adjacent second insulating strips 107 along the second direction Y is the first distance D1, and the distance between two adjacent third insulating strips 108 along the second direction Y is the second distance D2. The first distance D1 is greater than the second distance D2. Thus, compared to 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. This allows more photogenerated carriers on the cell body 10 to be effectively collected by the fine grid 101 and ultimately collected by the solder ribbon 105, thereby further improving the photoelectric conversion efficiency of the back-contact photovoltaic module.

[0111] It should be noted that, Figure 14 The insulating strips 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 spacing D1 can be 1.3 mm and the second spacing D2 can be 0.42 mm.

[0113] In some examples, there are multiple fine grids 101 that are interrupted by the main grid 102 along the first direction X. Among them, the fine grids 101 on opposite sides of the pad 103 along the first direction X are protected by the first insulating strip 104, and the fine grids 101 away from the first insulating group 114 are protected by the third insulating strip 108. Two adjacent third insulating strips 108 located on both sides of the main grid 102 along the second direction Y are regarded as a third insulating group. 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 multiple third insulating groups can be gradually increased to further reduce the total layout area of ​​the third insulating strips 108 on the cell body 100.

[0114] In some embodiments, the cell body 100 is a BC cell (Back Contact cell), which includes, but is not limited to, IBC cells (Interdigitated Back Contact cells), HBC cells (Heterojunction Back Contact cells), TBC cells (TOPCon Back Contact cells), or HPBC cells (Hybrid Passivated Back Contact cells). Furthermore, the cell body 100 can be a single cell or a sliced ​​cell; a sliced ​​cell refers to a cell formed by cutting a single, complete cell.

[0115] In some embodiments, the back-contact photovoltaic module further includes an encapsulation layer covering the surface of the cell body 100. The encapsulation layer can be made of organic encapsulation films such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene elastomer (POE) film, or polyethylene terephthalate (PET) film. Alternatively, the encapsulation layer can also be an EP film, EPE film, or PVP film. EP film refers to a co-extruded film composed of stacked EVA and POE films; EPE film refers to a co-extruded film formed by sequentially stacking EVA, POE, and EVA films; and PVP film refers to a co-extruded film formed by stacking POE, EVA, and POE films. The co-extruded film can be prepared by sequentially extruding one or more raw materials onto another pre-made film during film processing, or by bonding different types of pre-made films together.

[0116] In some embodiments, the back-contact photovoltaic module further includes a cover plate located on the surface of the encapsulation layer away from the cell body 100. The cover plate can be a glass cover plate, a plastic cover plate, or other cover plate that has light transmission function and is not easily damaged. In some embodiments, the surface of the cover plate facing the encapsulation layer can be an uneven surface or a textured surface containing multiple raised structures, thereby increasing the utilization rate of incident light.

[0117] In summary, the design of the first insulating strip 104, including the connecting portion 124, not only ensures that the solder ribbon 105, which is subsequently connected to the pad 103, will not contact the end of the discontinuous fine gate, thus avoiding short circuits between the first fine gate 111 and the second fine gate 121, but also provides a higher support point for the solder ribbon 105. This allows the solder ribbon 105 to be supported by both the pad 103 and the connecting portion 124 along the second direction Y, which helps to increase the overall raised portion of the solder ribbon 105. This, on the one hand, helps to avoid excessive local bending of the solder ribbon 105; on the other hand, it helps to reduce the risk of the solder ribbon causing excessive stress on the adjacent main gate 102 and fine gate 101, making them prone to breakage; furthermore, the connecting portion 124 covering the main gate 102 helps to prevent the raw material of the solder ribbon 105 from melting and dripping onto the main gate 102 under high-temperature conditions, thus preventing the molten raw material of the solder ribbon 105 from causing the main gate 102 to break, further reducing the risk of the main gate 102 breaking. Furthermore, the design of at least one first insulating strip 104 near the pad 103 includes a protrusion 134 that protrudes towards the pad 103, and the protrusion 134 covers a portion of a fine grid 101 located between the pad 103 and the first insulating strip 104, which can effectively prevent the fine grid 101 from breaking. Therefore, under the multiple functions of the first insulating strip 104, it not only helps to effectively reduce the risk of breakage of the fine grid 101 or the main grid 102, but also helps to reduce the bending degree of the solder ribbon 105 itself, thereby reducing the stress generated by the solder ribbon 105 on the cell body 100, thus effectively improving the structural stability of the back contact photovoltaic module.

[0118] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the embodiments of this disclosure. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the embodiments of this disclosure; therefore, the scope of protection of the embodiments of this disclosure should be determined by the scope defined in the claims.

Claims

1. A back-contact photovoltaic module, characterized in that, include: The battery cell body has a first fine grid and a second fine grid arranged alternately along a first direction on its back side, and a first main grid and a second main grid arranged alternately along a second direction. The first fine grid is broken at the second main grid, and the second fine grid is broken at the first main grid. Multiple pads, a single pad being located at the break point of the first fine gate and connected to the second main gate, or located at the break point of the second fine gate and connected to the first main gate; Multiple first insulating strips extending along the second direction, with at least two first insulating strips forming a first insulating group. The first insulation group corresponds one-to-one with the solder pads; 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 each first insulation strip includes at least a connecting portion that covers a portion of the main gate connected to the pad, and covers the two ends of two branches of a fine gate that is disconnected by the main gate, wherein the main gate is one of the first main gate and the second main gate, and the fine gate is one of the first fine gate and the second fine gate; At least one of the first insulating strips near the pad also includes a protrusion that bulges toward the pad, and the protrusion covers a portion of the fine gate located between the pad and the first insulating strip.

2. The back-contact photovoltaic module according to claim 1, characterized in that, Also includes: Multiple solder strips are spaced apart along the second direction, and one of the solder strips is located on one of the main gates. The solder strips are at least connected to the pads. The protrusions also cover a portion of the main gate connected to the pads. With the plane formed by the first direction and the second direction as a reference plane, the orthographic projection of the protrusions on the reference plane and the orthographic projection of the solder strips on the reference plane overlap with the orthographic projection of the protrusions on the reference plane corresponding to the same main gate.

3. The back-contact photovoltaic module according to claim 1 or 2, characterized in that, Along the second direction, the length of the protrusion 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 protrusion 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, The pads are positioned on opposite sides along the first direction, namely the upper side and the lower side. The first insulating strip closest to the upper side and / or the lower side includes the connecting portion and the protruding portion. Wherein, along the first direction, the distance between the pad and the protrusion is greater than or equal to 0.20 mm.

6. The back-contact photovoltaic module according to claim 1 or 2, characterized in that, Each of the first insulating strips includes at least the connecting portion and at least one extension portion, wherein a single extension portion connects one end of the connecting portion to one of the opposite ends 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.

7. The back-contact photovoltaic module according to claim 1 or 2, characterized in that, The pads are positioned on opposite sides, an upper side and a lower side, along the first direction. At least two connecting portions are arranged at intervals near one of the upper and lower sides, and the lengths of the at least two connecting portions decrease sequentially in the second direction along the direction away from the pads.

8. The back-contact photovoltaic module according to claim 1 or 2, characterized in that, Along the direction away from the pad, the thickness of the connecting portion, at least the portion furthest from the pad, gradually decreases in the third direction; and / or, At least two of the connecting portions arranged at intervals along one of the opposite sides of the pad in the first direction are considered as a group of connecting portions. In a single group of connecting portions, the thickness of at least two of the connecting portions decreases successively in the third direction in the direction away from the pad. The third direction refers to 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 being connected to a fine grid located between the pad and the first insulating strip, and the other end of the connecting portion being 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, each second insulating strip being located on one side of opposite sides of the pad along the second direction and covering at least a portion of one of the two branches of the fine gate interrupted by the pad; and / or, Multiple 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, each of the third insulating strips covering at least a portion of one of the two branches of the fine gate that is disconnected by the main gate.

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