Back contact photovoltaic module

Abstract

The embodiment of the present disclosure relates to the photovoltaic field, and provides a back contact photovoltaic module, which comprises a cell substrate, a plurality of main grids and a plurality of auxiliary grids arranged on the back surface of the cell substrate, the main grids comprise first and second main grids alternately arranged along a second direction, and the auxiliary grids comprise first and second auxiliary grids alternately arranged along a first direction; a plurality of conductive blocks, each conductive block is located at a break of the first auxiliary grid and connected to the second main grid or located at a break of the second auxiliary grid and connected to the first main grid; and insulating pieces extending along the second direction, at least two insulating pieces are respectively located on two opposite sides of the same conductive block along the first direction, the insulating piece comprises an insulating pad and at least one extension piece, the extension piece is connected to one end of the insulating pad on two opposite sides along the second direction; the insulating pad covers a partial area of the main grid connected to the conductive block, the extension piece covers a partial area of one auxiliary grid broken by the main grid, and the width of the insulating pad is greater than the width of the extension piece, thereby at least improving the structural stability of the back contact photovoltaic module.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to the field of photovoltaics, and in particular to a back contact photovoltaic module. BACKGROUND

[0002] At present, with the gradual depletion of fossil energy, photovoltaic cells are used more and more widely as a new energy alternative. Photovoltaic cells are devices that convert solar light energy into electrical energy. Photovoltaic cells use the photovoltaic principle to generate carriers, and then use electrodes to lead out the carriers, thereby facilitating the effective use of electrical energy. The grid lines of the photovoltaic cells play an important role in collecting and transmitting electrons. When a photovoltaic module is assembled using multiple photovoltaic cells, an interconnector is 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 sub-grid, and the main grid is provided with a conductive block. The interconnector realizes electrical connection with the main grid through the conductive block to collect the current on the main grid. The interconnector and the sub-grid are arranged in different directions, so the interconnector needs to cross the sub-grid of different polarity while connecting the sub-grid of the same polarity. In order to prevent short circuit caused by the interconnector connecting the sub-grids of different polarity, an insulating part needs to be designed on the sub-grid of different polarity of the interconnector.

[0004] However, the design of the insulating part not only affects the stress caused by the connection between the interconnector and the conductive block on the cell, but also affects the conductive performance of the sub-grid near the conductive block, for example, causing excessive bending of the interconnector, serious warping of the cell, or breakage of part of the main grid or sub-grid, thereby affecting the structural stability of the back contact photovoltaic module. SUMMARY

[0005] Embodiments of the present disclosure provide a back contact photovoltaic module, which at least facilitates improving the structural stability of the back contact photovoltaic module.

[0006] According to some embodiments of the present disclosure, the present disclosure provides a back contact photovoltaic module, comprising: a cell substrate, a back surface of the cell substrate being provided with a plurality of main grids and a plurality of auxiliary grids, the main grids comprising first main grids and second main grids arranged alternately along a second direction, the auxiliary grids comprising first auxiliary grids and second auxiliary grids arranged alternately along a first direction, and the first auxiliary grids being disconnected at the second main grids, and the second auxiliary grids being disconnected at the first main grids; a plurality of conductive blocks, each of the conductive blocks being located at a disconnection of the first auxiliary grid and connected to the second main grid, or being located at a disconnection of the second auxiliary grid and connected to the first main grid; and insulating pieces extending along the second direction, at least two of the insulating pieces being respectively located on opposite sides of each of the conductive blocks along the first direction, each of the insulating pieces comprising an insulating pad and at least one extension piece, each of the extension pieces being connected to one of opposite ends of the insulating pad along the second direction; wherein the insulating pad covers at least a partial area of the main grid connected to the conductive block, and the extension piece covers a partial area of the auxiliary grid disconnected by the main grid, and along the first direction, a first width of the insulating pad is greater than a second width of the extension piece.

[0007] In some embodiments, the insulating pad further covers at least one end of two branches of the auxiliary grid disconnected by the main grid; and / or, the insulating piece comprises two extension pieces, each of the extension pieces being connected to one of opposite ends of the insulating pad along the second direction.

[0008] In some embodiments, along a third direction, a first thickness of the insulating pad is greater than a second thickness of the extension piece, the third direction being a thickness direction of the cell substrate; and / or, along a direction away from the main grid, the second thickness of the extension piece gradually decreases.

[0009] In some embodiments, the back contact photovoltaic module further comprises: at least one connection grid line extending along the first direction, one end of the connection grid line being connected to one of the auxiliary grids between the conductive block and the insulating piece, and the other end of the connection grid line being connected to the conductive block.

[0010] In some embodiments, at least one of the insulating pieces close to the conductive block further comprises an extension part protruding towards the conductive block, and the extension part covers a partial area of one of the auxiliary grids between the conductive block and the insulating piece.

[0011] In some embodiments, the back contact photovoltaic module further comprises a plurality of interconnections arranged along the second direction, one of the interconnections is located on one of the main grids, and the interconnection is connected to at least the conductive block; the epitaxial part further covers a partial area of the main grid connected to the conductive block, and with a reference plane formed by the first direction and the second direction, in the epitaxial part and the interconnection corresponding to the same main grid, a normal projection of the epitaxial part on the reference plane and a normal projection of the interconnection on the reference plane have an overlap.

[0012] In some embodiments, opposite sides of the conductive block along the first direction are an upper side and a lower side, respectively, at least two of the insulating pads are arranged along one of the upper side and the lower side, and lengths of the at least two insulating pads in the second direction gradually decrease in a direction away from the conductive block.

[0013] In some embodiments, in a direction away from the conductive block, a thickness of the insulating pad farthest from the conductive block gradually decreases in a third direction; and / or, at least two of the insulating pads arranged along one of the opposite sides of the conductive block along the first direction are taken as an insulating pad group, in the insulating pad group, thicknesses of the at least two insulating pads in the third direction gradually decrease in a direction away from the conductive block; the third direction is a thickness direction of the cell substrate body.

[0014] In some embodiments, the back contact photovoltaic module further comprises: at least two first insulating blocks arranged along the first direction, the first insulating block comprising two first insulating sub-blocks arranged along the second direction, each of the first insulating sub-blocks being located on one of opposite sides of the conductive block along the second direction and covering at least a partial area of one of two branches of the auxiliary grid disconnected by the conductive block; and / or, at least two second insulating blocks arranged along the first direction, the second insulating block comprising two second insulating sub-blocks arranged along the second direction, each of the second insulating sub-blocks covering at least a partial area of one of two branches of one of the auxiliary grids disconnected by the main grid.

[0015] In some embodiments, along the second direction, a spacing between two of the first insulating sub-blocks in the same first insulating block is a first spacing, a spacing between two of the second insulating sub-blocks in the same second insulating block is a second spacing, and the first spacing is greater than the second spacing.

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

[0017] The design of the insulating piece includes the insulating pad, which not only protects part of the main grid to reduce the risk of breaking the main grid, but also provides a higher support point for the interconnection piece, so that the interconnection piece is supported by the conductive block and the insulating pad together in the second direction, which is conducive to increasing the overall elevated part of the interconnection piece. In this way, on the one hand, it is conducive to avoiding excessive bending of the interconnection piece itself; on the other hand, it is conducive to reducing the risk of the interconnection piece causing greater stress to the main grid and the auxiliary grid adjacent thereto, thereby making them prone to breaking; on the other hand, the insulating pad covers the main grid, which is conducive to avoiding the risk of the interconnection piece melting downward to the main grid under high temperature conditions, so as to avoid the phenomenon of breaking the main grid caused by the melted raw materials of the interconnection piece under high temperature conditions, thereby further reducing the risk of breaking the main grid.

[0018] Moreover, the insulating piece further includes an extension piece covering part of the auxiliary grid disconnected by the main grid, which is conducive to ensuring that the interconnection piece connected to the conductive block in the subsequent process does not contact the end of the disconnected part of the auxiliary grid, thereby avoiding the short circuit problem between the first auxiliary grid and the second auxiliary grid. Further, the width of the extension piece is designed to be smaller than the width of the insulating pad, which is conducive to improving the insulation effect of the insulating piece on the auxiliary grid covered thereby while reducing the amount of insulating material required to form the extension piece, and avoiding the warping problem of the back contact photovoltaic module caused by the volume shrinkage of the large-area insulating material.

[0019] In summary, under the multi-faceted role of the insulating piece, not only is it conducive to avoiding the short circuit problem between the first auxiliary grid and the second auxiliary grid, and effectively reducing the risk of breaking the auxiliary grid or the main grid, but also is conducive to reducing the bending degree of the interconnection piece itself, thereby reducing the stress generated by the interconnection piece on the cell substrate, and effectively improving the structural stability of the back contact photovoltaic module. BRIEF DESCRIPTION OF DRAWINGS

[0020] One or more embodiments are illustrated by way of example in the drawings that are for illustrative purposes only, and not for the purpose of limiting the embodiments, unless otherwise specifically stated in the specification. The drawings in the accompanying drawings are not to scale; in order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or in the prior art, a brief introduction will be given to the drawings needed in the embodiments. Obviously, the drawings described below only constitute some embodiments of the present disclosure, and those skilled in the art can also obtain other drawings from these drawings without creative labor.

[0021] Figure 1 A first partial top view schematic diagram of a back contact photovoltaic module provided by an embodiment of the present disclosure;

[0022] Figure 2 A partial cross-sectional schematic diagram of a back contact photovoltaic module provided by an embodiment of the present disclosure;

[0023] Figure 3 A second partial top view schematic diagram of a back contact photovoltaic module according to an embodiment of the present disclosure is provided;

[0024] Figure 4 A top view schematic diagram of an insulation member in a back contact photovoltaic module according to an embodiment of the present disclosure is provided;

[0025] Figure 5 A third partial top view schematic diagram of a back contact photovoltaic module according to an embodiment of the present disclosure is provided;

[0026] Figure 6 A fourth partial top view schematic diagram of a back contact photovoltaic module according to an embodiment of the present disclosure is provided;

[0027] Figure 7 Another cross-sectional schematic diagram of an insulation member in a back contact photovoltaic module according to an embodiment of the present disclosure is provided;

[0028] Figure 8 A fifth partial top view schematic diagram of a back contact photovoltaic module according to an embodiment of the present disclosure is provided;

[0029] Figure 9 Another partial cross-sectional schematic diagram of a back contact photovoltaic module according to an embodiment of the present disclosure is provided;

[0030] Figure 10 Still another partial cross-sectional schematic diagram of a back contact photovoltaic module according to an embodiment of the present disclosure is provided;

[0031] Figure 11 A sixth partial top view schematic diagram of a back contact photovoltaic module according to an embodiment of the present disclosure is provided;

[0032] Figure 12 A cross-sectional schematic diagram of a first insulation sub-block in a back contact photovoltaic module according to an embodiment of the present disclosure is provided;

[0033] Figure 13 A cross-sectional schematic diagram of a second insulation sub-block in a back contact photovoltaic module according to an embodiment of the present disclosure is provided;

[0034] Figure 14 A partial top view schematic diagram of an insulation structure corresponding to a sub-grid in a back contact photovoltaic module according to an embodiment of the present disclosure is provided. DETAILED DESCRIPTION

[0035] As known from the background art, the structural stability of a back contact photovoltaic module needs to be improved.

[0036] The back contact photovoltaic module provided by the disclosure can reduce the risk of main grid fracture and provide higher support points for the interconnection piece, so that the interconnection piece is supported by the conductive block and the insulating pad in the second direction, and the overall elevated part of the interconnection piece is increased. In this way, on the one hand, the bending degree of the interconnection piece itself is reduced; on the other hand, the risk of fracture of the main grid caused by the stress of the interconnection piece on the main grid and the auxiliary grid is reduced; and on the other hand, the insulating pad covers the main grid, which can prevent the interconnection piece from melting and falling onto the main grid under high temperature conditions, thereby preventing the main grid from being broken by the melted material of the interconnection piece under high temperature conditions, and further reducing the risk of main grid fracture. Moreover, the insulating piece further comprises an extension piece covering a part of the auxiliary grid disconnected by the main grid, which can prevent the interconnection piece connected to the conductive block from contacting the end of the disconnected part of the auxiliary grid, thereby avoiding the short circuit problem between the first auxiliary grid and the second auxiliary grid. Furthermore, the width of the extension piece is smaller than the width of the insulating pad, which can reduce the amount of insulating material required to form the extension piece, and avoid the warping problem of the back contact photovoltaic module caused by the volume shrinkage of the large-area insulating material. In summary, under the action of the insulating piece in multiple aspects, the short circuit problem between the first auxiliary grid and the second auxiliary grid is avoided, the risk of fracture of the auxiliary grid or the main grid is effectively reduced, and the bending degree of the interconnection piece itself is reduced, thereby reducing the stress of the interconnection piece on the battery substrate, and effectively improving the structural stability of the back contact photovoltaic module.

[0037] In the description of the embodiments of the disclosure, the technical terms "first", "second", and the like 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 disclosure, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0038] In this document, the term "embodiment" means that the specific features, structures or characteristics described in conjunction with the embodiment can be included in at least one embodiment of the disclosure. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0039] In the description of the embodiments of the present disclosure, the term "and / or" is only a description of the association relationship of the associated objects, that is, there can be three relationships, for example, A and / or B, which can represent: there is A, there is A and B, and there is B. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0040] In the description of the embodiments of the present disclosure, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0041] In the description of the embodiments of the present disclosure, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the present disclosure and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present disclosure.

[0042] In the description of the embodiments of the present disclosure, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present disclosure can be understood according to the specific circumstances.

[0043] In the corresponding drawings of the embodiments of the present disclosure, in order to better understand and facilitate the description, the thickness and area of the layer are enlarged. When describing that a component (such as a layer, a film, a region or a substrate) is on or on the surface of another component, the component can be "directly" on the surface of the other component, or there can be a third component between the two components. On the contrary, when describing that a component is on the surface of another component or a component surface is formed or provided with another component, it means that there is no third component between the two components. In addition, when describing that a component is "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 the edge of the entire surface.

[0044] In the description of the embodiments of the present disclosure, when a certain component "includes" another component, unless otherwise specified, other components are not excluded, and other components can be further included. In addition, when a layer, film, region, plate, or the like is referred to as "on" another component, it can be "directly on" the other component (i.e., between the other component and the surface of the other component, there is no other component), or there can be another component therebetween. In addition, when a layer, film, region, plate, or the like is "directly on" another component, or when a layer, film, region, plate, or the like is on the surface of another component, it means that there is no other component therebetween.

[0045] The terms used in the description of the various described embodiments herein are for the purpose of describing particular embodiments only and are not intended to be limiting. As used in the description of the various embodiments and the appended claims, the article "a", "an" is intended to include one or more articles based on the context in which the word is used. Therein, the components include a layer, film, region, or plate, and the like.

[0046] The embodiments of the present disclosure will be described in detail below with reference to the drawings. However, those skilled in the art can understand that in the embodiments of the present disclosure, in order to enable the reader to better understand the embodiments of the present disclosure, many technical details are presented. However, the technical solutions claimed by the embodiments of the present disclosure can be implemented even without these technical details and based on various changes and modifications of the following embodiments.

[0047] An embodiment of the present disclosure provides a solar cell, and the solar cell provided by the embodiment of the present disclosure will be described in detail below with reference to the drawings.

[0048] Reference Figures 1 to 4The back contact photovoltaic module comprises a cell substrate 100, a back surface 100a of the cell substrate 100 is provided with a plurality of main grids 101 and a plurality of auxiliary grids 102, the main grid 101 comprises a first main grid 111 and a second main grid 121 which are alternately arranged along a second direction Y, the auxiliary grid 102 comprises a first auxiliary grid 112 and a second auxiliary grid 122 which are alternately arranged along a first direction X, and the first auxiliary grid 112 is disconnected at the second main grid 121, and the second auxiliary grid 122 is disconnected at the first main grid 111; a plurality of conductive blocks 103, a single conductive block 103 is located at the disconnected position of the first auxiliary grid 112 and connected to the second main grid 121, or located at the disconnected position of the second auxiliary grid 122 and connected to the first main grid 111; an insulating piece 104 extending along the second direction Y, at least two insulating pieces 104 are respectively located on opposite sides of the same conductive block 103 along the first direction X, and the insulating piece 104 comprises an insulating pad 114 and at least one extension piece 124, a single extension piece 124 is connected to one of opposite ends of the insulating pad 114 along the second direction Y; wherein the insulating pad 114 covers at least a part of the main grid 101 connected to the conductive block 103, the extension piece 124 covers a part of the auxiliary grid 102 disconnected by the main grid 101, and along the first direction X, a first width W1 of the insulating pad 114 is greater than a second width W2 of the extension piece 124.

[0049] It should be noted that, Figure 1 A first partial top view schematic diagram of a back contact photovoltaic module 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 A second partial top view schematic diagram of a back contact photovoltaic module provided by an embodiment of the present disclosure, Figure 4 A top view schematic diagram of an insulating piece in a back contact photovoltaic module provided by an embodiment of the present disclosure. In order to distinguish the first auxiliary grid 112 and the second auxiliary grid 122, Figure 1 and Figure 2 In the above-mentioned figures, the first auxiliary grid 112 is schematically shown by a thick solid line, the second auxiliary grid 122 is schematically shown by a thick dashed line, and Figure 1 In the above-mentioned figures, the insulating piece 104 is drawn by a perspective drawing method. In addition, the same as the auxiliary grid 102 refers to one of the first auxiliary grid 112 and the second auxiliary grid 122, the main grid 101 refers to one of the first main grid 111 and the second main grid 121, the conductive block 103 described in the subsequent paragraphs can refer to one of the first conductive block 113 or the second conductive block 123, and the interconnection 106 can refer to one of the first interconnection 116 or the second interconnection 126.

[0050] In addition, in order to clearly show the positional relationship among the main grid 101, the auxiliary grid 102 and the conductive block 103, Figure 3 In the above-mentioned figures, only two interconnections 106 are schematically shown, and the interconnection 106 is drawn by a perspective drawing method.Figure 4 The insulation pads 114 and the extension pieces 124 included in the insulation piece 104 are divided by a dashed line.

[0051] It is worth noting that in the back contact photovoltaic module provided by the embodiment of the present disclosure, the insulation piece is specially designed for the surrounding of the conductive block 103. Specifically, at least two insulation pieces 104 are respectively located on the opposite sides of the same conductive block 103 along the first direction X, that is, at least one insulation piece 104 is arranged on the opposite sides of the conductive block 103 along the first direction X. In other words, the at least two insulation pieces 104 located on the opposite sides of the same conductive block 103 along the first direction X can be regarded as an insulation group, and a group of insulation groups is arranged around the conductive block 103.

[0052] Moreover, any insulation piece 104 includes an insulation pad 114 and at least one extension piece 124, and the insulation pad 114 covers at least part of the area of the main grid 101 connected with the conductive block 103. In this way, the insulation pad 114 not only protects part of the area of the main grid 101 to reduce the risk of breakage of the main grid 101, but also provides a higher support point for the interconnection piece 106.

[0053] In some cases, in combination with reference to Figure 2 and Figure 3, the solder tape 136 in the interconnection 106 is electrically connected with the conductive block 103 by the tin paste 146 in the interconnection 106, but the conductive block 103 overlaps the main grid 101 in the third direction Z, and based on the tin paste 146 in the interconnection 106, a certain height difference exists between the interconnection 106 and the main grid 101, and the design of the insulating pad 114 also overlaps the main grid 101, which can make the subsequent interconnection 106 formed in the second direction Y be supported by a higher support point in more areas, in other words, the part of the solder tape 136 in the interconnection 106 not only in contact with the conductive block 103 is lifted, but also the part in contact with the insulating pad 114 is lifted, thereby facilitating the increase of the overall part of the solder tape 136 being lifted. In this way, on the one hand, it is beneficial to avoid the local bending degree of the solder tape 136 being too large, that is, from the perspective of the entire interconnection 106, the bending degree of the solder tape 136 per unit length is reduced, and not only the part of the solder tape 136 in contact with the conductive block 103 is lifted, in other words, it is beneficial to slow down the bending trend of the solder tape 136; on the other hand, avoiding the local bending degree of the solder tape 136 being too large is beneficial to reduce the risk of the interconnection 106 causing a relatively large stress to the main grid 101 and the sub-grid 102 adjacent thereto, thereby making them prone to breakage; on the other hand, the insulating pad 114 covers the main grid 101, which is beneficial to avoid the risk of the raw material of the interconnection 106 melting and dripping downward to the main grid 101 under high temperature conditions, and to avoid the raw material of the interconnection 106 melting under high temperature conditions causing the main grid 101 to break, thereby further reducing the risk of the main grid 101 breaking. It is worth emphasizing that the bending degree of the interconnection 106 described in the subsequent paragraphs mainly refers to the bending degree of the solder tape 136 in the interconnection 106.

[0054] Furthermore, with reference to Figure 1 and Figure 4 For any insulating piece 104, it includes the insulating pad 114 and at least one extension piece 124, the extension piece 124 covers part of the area of a sub-grid 102 broken by the main grid 101, which is beneficial to ensure that the subsequent interconnection 106 connected with the conductive block 103 will not be in contact with the end of the broken part of the opposite sub-grid, thereby avoiding causing a short circuit problem between the first sub-grid 112 and the second sub-grid 122. Further, the second width W2 of the extension piece 124 is designed to be smaller than the first width W1 of the insulating pad 114, which is beneficial to improve the insulation effect of the insulating piece 104 on the sub-grid 102 covered thereby by means of the extension piece 124, while reducing the amount of insulating material required to form the extension piece 124, thereby reducing the amount of insulating material required to form the insulating piece 104, thereby facilitating the reduction of the preparation cost of the insulating piece 104, and avoiding the warping problem of the back contact photovoltaic module caused by the volume shrinkage of the large-area insulating material.

[0055] In summary, under the action of the insulating pieces 104, not only the short circuit problem between the first bus bars 112 and the second bus bars 122 is avoided, and the risk of breakage of the bus bars 102 or the main bus bars 101 is effectively reduced, but also the bending degree of the interconnecting pieces 106 is reduced, so as to reduce the stress of the interconnecting pieces 106 on the battery substrate 100, thereby effectively improving the structural stability of the back contact photovoltaic module.

[0056] It is worth emphasizing that each insulating piece 104 only covers one of the bus bars 102 of the opposite polarity which is disconnected by the main bus bar 101, and the insulating piece 104 is only designed on a part of the bus bars 102 close to the conductive blocks 103 along the first direction X. In this way, compared with laying a large area of insulating material around the conductive blocks, the insulating piece 104 is designed to cover the area of the main bus bar 101 and the bus bar 102 where the breakage is prone to occur as much as possible, so as to reduce the risk of breakage of the main bus bar 101 and the bus bar 102, and reduce the bending degree of the interconnecting piece 106 connected to the conductive block 103, while reducing the total layout area of the insulating piece 104 on the battery substrate 100, so as to reduce the amount of insulating material required to form the insulating piece 104, thereby reducing the preparation cost of the insulating piece 104 and avoiding the warping problem of the back contact photovoltaic module caused by the volume shrinkage of the large-area insulating material.

[0057] It is worth noting that based on the different polarities, the bus bars 102 can be divided into two types of first bus bars 112 and second bus bars 122, and the main bus bars 101 can be divided into two types of first main bus bars 111 and second main bus bars 121, the first main bus bars 111 are used to collect the current on all the first bus bars 112, and the second main bus bars 121 are used to collect the current on all the second bus bars 122. Based on this, the conductive blocks 103 can also be divided into two types of first conductive blocks 113 and second conductive blocks 123, the first conductive blocks 113 are located at the disconnected part of the second bus bars 122 and connected to the first main bus bars 111, and the second conductive blocks 123 are located at the disconnected part of the first bus bars 112 and connected to the second main bus bars 121. Among them, the disconnected part of the second bus bar 122 is used for the first main bus bar 111 to extend along the first direction X and electrically connected to the plurality of first bus bars 112, and the disconnected part of the first bus bar 112 is used for the second main bus bar 121 to extend along the first direction X and electrically connected to the plurality of second bus bars 122.

[0058] Further, based on the different types of the conductive blocks 103 connected, the interconnecting pieces 106 can also be divided into two types of first interconnecting pieces 116 and second interconnecting pieces 126, the first interconnecting pieces 116 are in contact with the first conductive blocks 113 to collect the current on the first main bus bars 111, and the second interconnecting pieces 126 are in contact with the second conductive blocks 123 to collect the current on the second main bus bars 121.

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

[0060] In some embodiments, referring to Figure 1 , the insulating pad 114 also covers at least one end of the two branches of one of the auxiliary gates 102 that is broken by the main gate 101. It should be noted that, Figure 1 In the above embodiment, only the two ends of the two branches of one of the auxiliary gates 102 that is broken by the main gate 101 are covered by the single insulating pad 114 as an example. In actual applications, in the above embodiment, the single insulating pad can only cover one end of the two branches of one of the auxiliary gates that is broken by the main gate, and the other end is covered by the extension piece; or, the single insulating pad can only cover a part of the main gate, and the two ends of the two branches of one of the auxiliary gates that is broken by the main gate are respectively covered by two extension pieces.

[0061] It should be noted that, whether the two ends of the two branches of one of the auxiliary gates that is broken by the main gate are covered by the insulating pad 114 or the extension piece 124, the interconnection piece 106 connected to the conductive block 103 will not be in contact with the end of the broken part of the auxiliary gate of the opposite sex.

[0062] In some embodiments, referring to Figure 1 , the insulating piece 104 includes two extension pieces 124, and the two extension pieces 124 are respectively connected to the opposite two ends of the insulating pad 114 in the second direction Y. In this way, it is beneficial to improve the integrity and symmetry of the insulating effect of the insulating piece 104 on the auxiliary gate 102 covered thereby. In other cases, any insulating piece can also include an insulating pad and an extension piece, the extension piece is connected to one of the opposite two ends of the insulating pad in the second direction, and the insulating piece covers the two ends of the two branches of one of the auxiliary gates that is broken by the main gate.

[0063] In some embodiments, referring to Figure 1 and Figure 2The first thickness of the insulating pad 114 is greater than the second thickness of the extension piece 124 in the third direction Z, which is the thickness direction of the battery substrate 100 body. It is worth noting that the interconnection 106 electrically connected with the conductive block 103 is mainly located on the insulating pad 114, and the solder strip 136 in the interconnection 106 is lifted by the insulating pad 114, for example, the height of the solder strip 136 lifted by the insulating pad 114 is consistent with the height of the solder strip 136 lifted by the conductive block 103 and the tin paste 146 together, and the extension pieces 124 on the opposite sides of the insulating pad 114 in the second direction Y only need to cover the auxiliary grid 102 to have a better protection effect. Based on this, the first thickness of the insulating pad 114 is designed to be greater than the second thickness of the extension piece 124, which is beneficial to increase the overall height of the solder strip 136 lifted by the insulating pad 114 while reducing the second thickness of the extension piece 124 to further reduce the amount of insulating material required to form the extension piece 124, thereby reducing the amount of insulating material required to form the insulating piece 104, thereby reducing the preparation cost of the insulating piece 104, and avoiding the warping problem of the back contact photovoltaic module caused by the volume shrinkage of the large-area insulating material.

[0064] In some embodiments, with reference to Figure 1 The second thickness of the extension piece 124 gradually decreases in the direction away from the main grid 101. It is worth noting that the farther away from the main grid 101 on the auxiliary grid 102 in the second direction Y, the less likely it is to contact the interconnection 106, and the less likely it is to cause short circuit caused by the connection of the interconnection 106 and the auxiliary grid. Based on this, the second thickness of the extension piece 124 is designed to gradually decrease in the direction away from the main grid 101, which is beneficial to further reduce the amount of insulating material required to form the extension piece 124 while ensuring the good protection effect of the extension piece 124 on the auxiliary grid 102, thereby effectively avoiding the short circuit problem between the first auxiliary grid 112 and the second auxiliary grid 122, reducing the amount of insulating material required to form the insulating piece 104, thereby reducing the preparation cost of the insulating piece 104, and avoiding the warping problem of the back contact photovoltaic module caused by the volume shrinkage of the large-area insulating material.

[0065] It should be noted that for the same extension piece 124, the second thickness of the extension piece 124 gradually decreases in the direction away from the main grid 101, and the second thickness of the extension piece 124 in the third direction Z can be considered as the thickness of the part with the maximum thickness of the extension piece 124, that is, the second thickness of the extension piece 124 can be considered as the maximum thickness of the extension piece 124, and the second thickness of the extension piece 124 can also be less than the first thickness of the insulating pad 114. In actual application, the thickness of each region of the extension piece in the third direction can also be consistent, and the second thickness of the extension piece can be considered as the thickness of any region of the extension piece, and the second thickness of the extension piece can also be less than the first thickness of the insulating pad.

[0066] In some embodiments, referring to Figure 5 , Figure 5 A third partial top view of a back contact photovoltaic module according to an embodiment of the present disclosure is provided, which can further comprise at least one connecting grid line 105 extending along the first direction X, one end of the connecting grid line 105 being connected to one of the sub-grids 102 between the conductive block 103 and the insulating member 104, and the other end of the connecting grid line 105 being connected to the conductive block 103.

[0067] It is worth noting that the sub-grid 102 between the insulating member 104 closest to the conductive block 103 and the conductive block 103 is most affected by the tin paste 146 in the interconnector 106. Generally, this sub-grid 102 will be in contact with the main grid 101 connected to the conductive block 103, but due to the influence of the tin paste 146 (refer to Figure 2 ) in the interconnector 106 (refer to Figure 2 ) or the stress applied by the interconnector 106 to the cell substrate 100, the area of the sub-grid 102 adjacent to the insulating member 104 and not covered by the insulating member 104 can also be at risk of fracture. Based on this, the connecting grid line 105 is designed to directly electrically connect the sub-grid 102 most prone to grid fracture to the conductive block 103, so that even if part of the area on the sub-grid 102 cannot transmit current to the main grid 101 due to fracture, it can be directly transmitted to the conductive block 103 through the connecting grid line 105. In other words, the design of the connecting grid line 105 is conducive to further ensuring that the interconnector 106 can collect current on all sub-grids 102 of the same polarity, such as all first sub-grids 112 or all second sub-grids 122, to improve the photoelectric conversion efficiency of the back contact photovoltaic module.

[0068] In some embodiments, referring to Figure 6 , Figure 6 A fourth partial top view of a back contact photovoltaic module according to an embodiment of the present disclosure is provided, and at least one insulating member 104 close to the conductive block 103 further comprises an extension 134 protruding towards the conductive block 103, and the extension 134 covers part of the area of one of the sub-grids 102 between the conductive block 103 and the insulating member 104. In other words, the extension 134 covers part of the area of one of the sub-grids 102 adjacent to the conductive block 103 and electrically connected to the conductive block 103, and since this sub-grid 102 is closest to the conductive block 103, the part of the interconnector 106 located directly above this sub-grid 102 is also more affected by the temperature when the interconnector 106 is in contact and connected, such as welded, to the conductive block 103. Designing the extension 134 to cover the sub-grid 102 at this location can effectively prevent the sub-grid 102 at this location from fracturing.

[0069] It is worth emphasizing that each insulation piece 104 includes the insulation pad 114 and the extension piece 124, but only a part of the insulation pieces 104 further include the extension part 134, for example, only the insulation pieces 104 closest to the conductive block 103 in the first direction X include the extension part 134, and in a single insulation group, only two insulation pieces 104 can include the extension part 134 and are respectively located on the opposite sides of the conductive block 103 in the first direction X. In this way, the risk of fracture of the auxiliary grid 102 closest to the conductive block 103 can be effectively reduced, and the total layout area of the insulation piece 104 on the battery substrate 100 can be as small as possible.

[0070] In some cases, with reference to Figure 7 , Figure 7 Another cross-sectional schematic view of the insulation piece in the back contact photovoltaic module provided by an embodiment of the present disclosure is provided, along the second direction Y, the length of the extension part 134 is a first length L1, the length of the insulation pad 114 is a second length L2, and the ratio of the first length L1 to the second length L2 is 1 / 2~1 / 5, 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.

[0071] With reference to Figure 6 and Figure 7 If the ratio of the first length L1 to the second length L2 is less than 1 / 5, the area of the auxiliary grid 102 adjacent to the conductive block 103 in the first direction X covered by the extension part 134 is small, which is not conducive to improving the protection effect of the extension part 134 on the auxiliary grid 102; if the ratio of the first length L1 to the second length L2 is greater than 1 / 2, the total layout area of the extension part 134 on the battery substrate 100 is large, which will affect the total layout area of the insulation piece 104 on the battery substrate 100, which is not conducive to reducing the volume of the insulation piece 104, and is also not conducive to preventing the back contact photovoltaic module from warping. Therefore, the ratio of the first length L1 to the second length L2 can be designed to be 1 / 5~1 / 2, which is conducive to ensuring the good protection effect of the extension part 134 on the auxiliary grid 102, effectively reducing the risk of fracture of the auxiliary grid 102, reducing the volume of the insulation piece 104, and preventing the back contact photovoltaic module from warping.

[0072] It should be noted that Figure 7 In the above description, the insulation pad 114, the extension piece 124 and the extension part 134 included in the insulation piece 104 are divided by a dashed line.

[0073] In some examples, along the second direction Y, the first length L1 of the extension part 134 can be greater than or equal to 0.20mm, for example, the first length L1 can be 0.25mm, 0.3m, 0.35mm, 0.4mm, 0.42mm, 0.45mm or 0.5mm, etc., to ensure the good protection effect of the extension part 134 on the auxiliary grid 102.

[0074] In some examples, the second length L2 of the insulating pad 114 along the second direction Y can be 1mm-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.

[0075] In combination with reference to Figure 6 and Figure 7 , if the second length L2 is less than 1mm, the length of the insulating pad 114 is short, and the supporting strength of the insulating pad 114 to the interconnector 106 (refer to Figure 3 ) is limited. When the interconnector 106 is placed on the conductive block 103 and connected, for example, welded to the conductive block 103, the interconnector 106 is prone to unstable placement, for example, tilting, resulting in relative displacement of the interconnector 106 and the conductive block 103, and the short length of the insulating pad 114 has a small stress buffering effect, which is prone to cause large local stress of the battery substrate 100 during welding. If the second length L2 is greater than 9mm, the length of the insulating pad 114 is long, and the total layout area of the insulating pad 114 on the battery substrate 100 is large, which affects the total layout area of the insulating member 104 on the battery substrate 100, is not conducive to reducing the volume of the insulating member 104, and is also not conducive to preventing the back contact photovoltaic module from warping. Therefore, the second length L2 is designed to be 1mm-9mm, which is conducive to reducing the volume of the insulating member 104 while ensuring that the insulating pad 114 has sufficient supporting strength to the interconnector 106 and good stress buffering effect, so as to effectively avoid the relative displacement of the interconnector 106 and the conductive block 103 and the stress concentration problem, and prevent the back contact photovoltaic module from warping seriously.

[0076] It should be noted that the ratio of the length of the extension part 134 to the length of the insulating pad 114 in different insulating members 104 along the second direction Y can be the same or different; the lengths of different extension parts 134 in different insulating members 104 can be the same or different; and the lengths of different insulating pads 114 in different insulating members 104 can be the same or different.

[0077] In some cases, in combination with reference to Figure 7 , along the first direction X, the width of the extension part 134 is a third width W3, and the ratio of the third width W3 to the first width W1 is 1 / 1-1 / 2, for example, the ratio of the third width W3 to the first width W1 can be 3 / 5, 7 / 10, 4 / 5 or 9 / 10, etc. Wherein, the first width W1 is the width of the insulating pad 114.

[0078] It is worth noting that, in combination with reference to Figure 6 and Figure 7 , the ratio of the third width W3 and the first width W1 in the same insulating piece 104 symbolizes the degree of protrusion of the extension part 134 relative to the insulating pad 114. If the ratio of the third width W3 and the first width W1 is less than 1 / 2, the degree of protrusion of the extension part 134 relative to the insulating pad 114 is small, the width of the part of the extension part 134 between the conductive block 103 and the sub-grid 102 closest to the conductive block 103 is small, and this part of the extension part 134 is at the edge of the insulating piece 104, which is prone to thickness reduction due to glue overflow, affecting the thickness of the extension part 134 around the sub-grid 102, thereby affecting the protection effect of the extension part 134 on the sub-grid 102; if the ratio of the third width W3 and the first width W1 is greater than 1 / 1, the degree of protrusion of the extension part 134 relative to the insulating pad 114 is large, and the distance between the extension part 134 and the conductive block 103 is small. The insulating material constituting the extension part 134, such as the insulating glue, is prone to overflow onto the conductive block 103, and when the interconnection piece 106 (see Figure 3 ) is welded on the conductive block 103, the raw material of the interconnection piece 106, such as the tin paste, is easily affected by the insulating glue overflowing onto the conductive block 103 and is divided into two halves, thereby causing poor contact between the interconnection piece 106 and the conductive block 103.

[0079] Therefore, the ratio of the third width W3 and the first width W1 can be designed to be 1 / 2~1 / 1, which is beneficial to make the thickness of the extension part 134 around the sub-grid 102 not too thin to ensure the good protection effect of the extension part 134 on the sub-grid 102, and is beneficial to make the extension part 134 and the conductive block 103 have a suitable distance, effectively avoiding the insulating material constituting the extension part 134 from overflowing onto the conductive block 103, so as to avoid poor contact between the interconnection piece 106 and the conductive block 103.

[0080] In some examples, along the first direction X, the third width W3 of the extension part 134 can be 0.2mm~0.3mm, for example, the third width W3 can be 0.22mm, 0.24mm, 0.25mm, 0.26mm or 0.28mm, etc.; the first width W1 of the insulating pad 114 can be 0.3mm~0.5mm, for example, the first width W1 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.

[0081] It should be noted that the ratio of the width of the extension part 134 to the width of the insulating pad 114 in different insulating pieces 104 along the first direction X can be the same or different; the width of different extension parts 134 in different insulating pieces 104 can be the same or different; and the width of different insulating pads 114 in different insulating pieces 104 can be the same or different.

[0082] In some cases, with reference to Figure 6 The opposite sides of the conductive block 103 along the first direction X are respectively the upper side 103a and the lower side 103b. One insulating piece 104 closest to the upper side 103a and / or the lower side 103b includes the insulating pad 114 and the extension part 134. Along the first direction X, the spacing S between the conductive block 103 and the extension part 134 is greater than or equal to 0.20 mm

[0083] It should be noted that Figure 6 The extension part 134 and the insulating pad 114 are included in one insulating piece 104 closest to the upper side 103a and one insulating piece 104 closest to the lower side 103b in the example. In actual applications, only one insulating piece closest to the upper side can include the insulating pad and the extension part, and the other insulating pieces do not include the extension part; or only one insulating piece closest to the lower side can include the insulating pad and the extension part, and the other insulating pieces do not include the extension part. Moreover, any insulating piece can include at least one extension piece 124.

[0084] It is worth emphasizing that along the first direction X, the spacing S between the conductive block 103 and the extension part 134 is greater than or equal to 0.20 mm, for example, the spacing S can be 0.25 mm, 0.3 m, 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 extension part 134 from overflowing onto the conductive block 103, so as to avoid poor contact between the interconnection piece 106 and the conductive block 103, thereby improving the structural stability of the back contact photovoltaic module.

[0085] In some embodiments, with reference to Figure 6 and Figure 3 The back contact photovoltaic module can further include: a plurality of interconnection pieces 106 spaced apart along the second direction Y, and one interconnection piece 106 is located on one main grid 101, and the interconnection piece 106 is connected to at least the conductive block 103; the extension part 134 further covers part of the area of the main grid 101 connected to the conductive block 103, and with reference to the plane formed by the first direction X and the second direction Y, among the extension part 134 and the interconnection piece 106 corresponding to the same main grid 101, the orthogonal projection of the extension part 134 on the reference plane and the orthogonal projection of the interconnection piece 106 on the reference plane have an overlap.

[0086] It is worth noting that when the interconnector 106 is contact-connected, such as welded, to the conductive block 103, not only the sub-grid 102 closest to the conductive block 103 is susceptible to the material melted by the interconnector 106 under high-temperature conditions, but also the main grid 101 closest to the conductive block 103 is susceptible to the material melted by the interconnector 106 under high-temperature conditions. Therefore, the design of the epitaxial part 134 not only covers the partial area of the sub-grid 102 closest to and electrically connected with the conductive block 103, but also covers the partial area of the main grid 101 connected with the conductive block 103, which is conducive to protecting the parts susceptible to breakage of the main grid 101 and the sub-grid 102 at the same time by using the epitaxial part 134, so as to further improve the structural stability of the back contact photovoltaic module.

[0087] Generally speaking, the sub-grid 102 and the main grid 101 located directly below the interconnector 106 are most susceptible to the material melted by the interconnector 106 under high-temperature conditions, and therefore, in the epitaxial part 134 and the interconnector 106 corresponding to the same main grid 101, the orthogonal projection of the epitaxial part 134 on the reference surface overlaps with the orthogonal projection of the interconnector 106 on the reference surface, which is conducive to ensuring that at least part of the area directly below the interconnector 106 is provided with the epitaxial part 134, so as to accurately protect the sub-grid 102 and the main grid 101 by using the epitaxial part 134.

[0088] It should be noted that the orthogonal projection of the epitaxial part 134 on the reference surface overlaps with the orthogonal projection of the interconnector 106 on the reference surface at least includes the following cases: in some cases, the orthogonal projection of the epitaxial part 134 on the reference surface is located in the orthogonal projection of the interconnector 106 on the reference surface; in other cases, the orthogonal projection of the interconnector 106 on the reference surface is located in the orthogonal projection of the epitaxial part 134 on the reference surface; in yet other cases, the orthogonal projection of the epitaxial part 134 on the reference surface only partially overlaps with the orthogonal projection of the interconnector 106 on the reference surface.

[0089] In some embodiments, the conductive block 103 has opposite sides along the first direction X, and the number of the insulating pads 114 arranged along the first direction X and spaced from one side of the conductive block 103 is 1-6. Figure 1 , Figure 5 or Figure 6 , the conductive block 103 has opposite sides along the first direction X, and the number of the insulating pads 114 arranged along the first direction X and spaced from one side of the conductive block 103 is 1-6. In other words, at least two insulating pads 114 arranged along the first direction X and spaced from one side of the conductive block 103 are taken as a group of insulating pads, and the number of the insulating pads 114, i.e. the number of the insulating members 104, in a single group of insulating pads is 1-6, and the number of the insulating pads 114, i.e. the number of the insulating members 104, in a single group of insulating pads is 2-12.

[0090] It is worth noting that during the process of welding the interconnect 106 on the conductive block 103, the portion of the interconnect 106 near the conductive block 103 is greatly affected by temperature. By covering the insulating pads 114 on the main grid 101 and the insulated auxiliary grid 102 opposite to the main grid 101 in the third direction Z, the risk of fracture of the auxiliary grid 102 and the main grid 101 can be significantly reduced, and the degree of bending of the solder strip 136 caused by the height difference between the conductive block 103 and the main grid 101 can be significantly reduced, without designing the insulating member 104 including the insulating pads 114 in the area far from the conductive block 103. In other words, the number of insulating pads 114 arranged in the second direction Y near one of the upper side 103a and the lower side 103b is designed to be 1-6, which can significantly reduce the risk of fracture of the auxiliary grid 102 and the main grid 101, significantly reduce the degree of bending of the solder strip 136, and avoid designing too many insulating pads 114 to increase the total layout area of the insulating member 104 on the battery substrate 100.

[0091] It should be noted that, Figure 1 , Figure 5 and Figure 6 The number of insulating pads 114 included in a single insulating pad group is only an example of 2 in actual application, and the number of insulating pads included in a single insulating pad group can also be 1, 3, 4, or 5, etc.

[0092] In some cases, the number of insulating pads 114 arranged near the upper side 103a can be equal to the number of insulating pads 114 arranged near the lower side 103b, which is beneficial to make the area of the interconnect 106 near the upper side 103a away from the lower side 103b raised by the insulating pads 114 consistent with the area of the interconnect 106 near the lower side 103b away from the upper side 103a raised by the insulating pads 114, and more beneficial to assist the gradual change of the bending degree of the interconnect 106. In one example, the conductive block 103 can have a center line extending in the second direction Y, and the insulating pad group on one side of the upper side 103a away from the lower side 103b can be axisymmetric with the insulating pad group on one side of the lower side 103b away from the upper side 103a along the center line.

[0093] It should be noted that in actual application, the number of insulating pads 114 arranged near the upper side 103a can also be different from the number of insulating pads 114 arranged near the lower side 103b, which can be adjusted according to specific needs.

[0094] The design of the length of the plurality of insulating pads 114 in the second direction Y in a single insulating pad group is described in detail below.

[0095] In some embodiments, referring to Figure 8 ,Figure 8 This is a fifth partial top view of a back-contact photovoltaic module according to an embodiment of the present disclosure. The conductive block 103 has two opposite sides along the first direction X, namely an upper side 103a and a lower side 103b. At least two insulating pads 114 are arranged at intervals near one of the upper side 103a and the lower side 103b. Furthermore, along the direction away from the conductive block 103, the lengths of the at least two insulating pads 114 in the second direction Y decrease sequentially. In other words, the at least two insulating pads 114 arranged at intervals near one of the opposite sides along the first direction X of the conductive block 103 are considered as a group of insulating pads. Along the direction away from the conductive block 103, the lengths of the at least two insulating pads 114 in a single insulating pad group decrease sequentially in the second direction Y, meaning that the insulating pads 114 further away from the conductive block 103 have smaller lengths in the second direction Y.

[0096] Thus, based on the change in distance from the conductive block 103, the interconnect 106 is welded onto the conductive block 103 (see reference). Figure 3 The design of insulating pads 114, which are further away from conductive block 103, has a shorter length in the second direction Y due to the influence of temperature. This not only helps to reduce the amount of insulating material required to form insulating pads 114, thereby reducing the manufacturing cost of insulating component 104 and avoiding the warping problem of back contact photovoltaic module caused by the volume shrinkage of large-area insulating material, but also helps to raise more areas in interconnect component 106 by using multiple insulating pads 114 located on the upper side 103a and lower side 103b of conductive block 103, so as to reduce the bending degree of interconnect component 106 itself and avoid excessive stress on battery substrate 100 caused by interconnect component 106.

[0097] In some cases, at least two insulating pads 114 arranged at intervals near one of the upper side 103a and the lower side 103b are considered as a group of insulating pads. In a single group of insulating pads, the length of the at least two insulating pads 114 in the second direction Y can be gradually reduced from 9 mm to 1 mm in the direction away from the conductive block 103.

[0098] For any insulating pad 114, if the length of the insulating pad 114 in the second direction Y is less than 1 mm, the length of the insulating pad 114 is short, and the supporting strength of the insulating pad 114 to the interconnection 106 is limited. When the interconnection 106 is placed on the conductive block 103 and connected, for example, welded to the conductive block 103, the interconnection 106 is prone to unstable placement due to the small supporting area of the insulating pad 114 to the interconnection 106, resulting in the relative displacement of the interconnection 106 and the conductive block 103, and the short length of the insulating pad 114 has a small stress buffering effect, which is prone to cause a large local stress of the battery substrate 100 during welding. If the length of the insulating pad 114 in the second direction Y is greater than 9 mm, the length of the insulating pad 114 is long, and the total layout area of the insulating pad 114 on the battery substrate 100 is large, which will affect the total layout area of the insulating member 104 on the battery substrate 100, which is not conducive to reducing the volume of the insulating member 104 and preventing the back contact photovoltaic module from warping.

[0099] In this way, the length of the at least two insulating pads 114 in the second direction Y can gradually decrease from 9 mm to 1 mm in the direction away from the conductive block 103, which is conducive to ensuring that the insulating pad 114 close to the conductive block 103 has sufficient supporting strength to the interconnection 106 and good stress buffering effect, so as to effectively avoid the relative displacement of the interconnection 106 and the conductive block 103 and the stress concentration problem, and the length of the insulating pad 114 farther away from the conductive block 103 in the second direction Y is smaller, so as to effectively reduce the layout area of the single insulating pad group on the battery substrate 100, prevent the back contact photovoltaic module from warping seriously, and reduce the preparation cost of the single insulating pad group.

[0100] The design of the thickness of the plurality of insulating pads 114 in the third direction Z in the single insulating pad group is described in detail below. The third direction Z is the thickness direction of the battery substrate 100.

[0101] In some embodiments, referring to Figure 9 , Figure 9 Another partial cross-sectional schematic view of the back contact photovoltaic module provided by an embodiment of the present disclosure is shown. The thickness of the at least one insulating pad 114 farthest away from the conductive block 103 gradually decreases in the third direction Z in the direction away from the conductive block 103.

[0102] In other embodiments, referring to Figure 10 , Figure 10A further partial cross-sectional view of the back contact photovoltaic module according to an embodiment of the present disclosure is provided, in which at least two insulating pads 114 arranged along one side of the conductive block 103 in the opposite side in the first direction X are taken as an insulating pad group, and in a single insulating pad group, the thickness of the at least two insulating pads 114 in the third direction Z gradually decreases in the direction away from the conductive block 103.

[0103] In the above two embodiments, with reference to Figure 9 or Figure 10 In a single insulating pad group, the height of the support points of the plurality of insulating pads 114 provided for the interconnection member 106 gradually decreases in the direction away from the conductive block 103, which helps to assist the gradual change of the bending degree of the interconnection member 106, effectively avoids the phenomenon that the bending degree of the local area of the interconnection member 106 is too large, thereby facilitating to slow down the degree of bending of the interconnection member 106 in the third direction Z as a whole, so as to further reduce the risk that the interconnection member 106 causes relatively large stress to the main grid 101 and the auxiliary grid 102 adjacent thereto and makes them prone to breakage. In addition, in a single insulating pad group, the thickness of the at least two insulating pads 114 in the third direction Z gradually decreases in the direction away from the conductive block 103, which is also conducive to effectively further reducing the amount of insulating material required by the single insulating pad group 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.

[0104] In some embodiments, with reference to Figure 11 , Figure 11 A sixth partial top view of the back contact photovoltaic module according to an embodiment of the present disclosure is provided, and the back contact photovoltaic module can further include: at least two first insulating blocks 107 arranged along the first direction X, the first insulating block 107 including two first insulating sub-blocks 117 arranged along the second direction Y, and a single first insulating sub-block 117 is located on one side of the opposite sides of the conductive block 103 in the second direction Y and covers at least part of the area of one of the two branches of the auxiliary grid 102 disconnected by the conductive block 103. In other words, for a single conductive block 103, the auxiliary grid 102 located on the opposite sides of the conductive block 103 in the second direction Y, i.e., the auxiliary grid 102 electrically insulated from the conductive block 103, is also designed with the first insulating block 107, which protects the end of the two branches of the auxiliary grid 102 disconnected by the conductive block 103, so that the conductive block 103 and the part of the auxiliary grid 102 also have insulating material, further avoiding the contact connection between the interconnection member 106 and the auxiliary grid 102 electrically insulated from the conductive block 103, so as to further avoid the short circuit phenomenon in the back contact photovoltaic module.

[0105] In some cases, along the second direction Y, the conductive block 103 is located between two adjacent first insulating sub-blocks 117, and the number of the auxiliary grids 102 disconnected by the conductive block 103 can be 2, or 1, 3 or 4, which can be selected according to the actual size of the conductive block 103.

[0106] In some cases, in combination with reference to Figure 11 and Figure 12 , Figure 12 A cross-sectional view of a first insulating sub-block in a back contact photovoltaic module according to an embodiment of the present disclosure is shown in FIG. 13. The first insulating sub-block 117 includes a first extension 127 and a first widened portion 137 close to the conductive block 103. The first widened portion 137 covers the end of one of the two branches of the auxiliary grid 102 disconnected by the conductive block 103. The first extension 127 is located on the side of the first widened portion 137 away from the conductive block 103, and along the first direction X, the width of the first widened portion 137 is a fourth width W4, and the width of the first extension 127 is a fifth width W5. The fourth width W4 is greater than the fifth width W5. In this way, for any interconnection 106 and the conductive block 103 in contact connection with the interconnection 106, not only can the first widened portion 137 be used to effectively avoid the contact connection between the interconnection 106 and the auxiliary grid 102 electrically insulated from the conductive block 103, but also the first extension 127 with a smaller width than the first widened portion 137 can be used to strengthen the protection of the auxiliary grid 102, and to reduce the total layout area of the first insulating sub-block 117 on the cell substrate 100 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.

[0107] It should be noted that, Figure 12 In FIG. 13, the first extension 127 and the first widened portion 137 included in the first insulating sub-block 117 are divided by a dashed line.

[0108] In some embodiments, in combination with reference to Figure 11The back contact photovoltaic module can further include: at least two second insulating blocks 108 arranged along the first direction X, the second insulating block 108 including two second insulating sub-blocks 118 arranged along the second direction Y, and each second insulating sub-block 118 covering at least part of an area of one of the two branches of the auxiliary grid 102 disconnected by the main grid 101. In other words, for a single main grid 101, the auxiliary grid 102 located on the opposite sides of the main grid 101 along the second direction Y, i.e., the auxiliary grid 102 electrically insulated from the main grid 101, is further provided with the second insulating block 108, which protects the end of the two branches of the auxiliary grid 102 disconnected by the main grid 101, so that the main grid 101 and the part of the auxiliary grid 102 also have insulating material therebetween, further avoiding the contact connection between the interconnector 106 and the auxiliary grid 102 electrically insulated from the main grid 101, so as to further avoid the short circuit phenomenon in the back contact photovoltaic module.

[0109] In some cases, reference is made to Figure 13 , Figure 13 A cross-sectional view of a second insulating sub-block in a back contact photovoltaic module according to an embodiment of the present disclosure is provided, the second insulating sub-block 118 including a second extension 128 and a second widened portion 138 close to the main grid 101, the second widened portion 138 covering the end of one of the two branches of the auxiliary grid 102 disconnected by the main grid 101, the second extension 128 being located on the side of the second widened portion 138 away from the main grid 101 and along the first direction X, the width of the second widened portion 138 being a sixth width W6, and the width of the second extension 128 being a seventh width W7, the sixth width W6 being greater than the seventh width W7. In this way, for any main grid 101 and conductive block 103 in contact with the main grid 101, not only can the contact between the main grid 101 and the auxiliary grid 102 electrically insulated from the conductive block 103 be effectively avoided by means of the second widened portion 138, but the protection of the auxiliary grid 102 can also be strengthened by means of the second extension 128 with a smaller width than the second widened portion 138, and the total layout area of the second insulating sub-block 118 on the cell substrate 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.

[0110] It should be noted that Figure 13 The second extension 128 and the second widened portion 138 included in the second insulating sub-block 118 are divided by a dashed line.

[0111] In some embodiments, the fourth width W4 of the first widened portion 137 along the first direction X can be smaller than the sixth width W6 of the second widened portion 138. As the first widened portion 137 is closer to the conductive block 103 than the second widened portion 138, designing the fourth width W4 of the first widened portion 137 to be smaller not only helps avoid the first insulating sub-block 117 overflowing to the conductive block 103, but also helps reduce the total layout area of the first insulating sub-block 117 on the battery substrate 100.

[0112] In some embodiments, the length of the first widened portion 137 along the second direction Y can be smaller than the length of the second widened portion 138. As the first widened portion 137 is closer to the conductive block 103 than the second widened portion 138, designing the length of the first widened portion 137 to be smaller not only helps avoid the first insulating sub-block 117 overflowing to the conductive block 103, but also helps reduce the total layout area of the first insulating sub-block 117 on the battery substrate 100.

[0113] In some embodiments, referring to Figure 14 , Figure 14 A partial top view schematic diagram of the insulating structure corresponding to the auxiliary grid in a back contact photovoltaic module provided by an embodiment of the present disclosure is shown in FIG. 6. Along the second direction Y, the spacing between two first insulating sub-blocks 117 in the same first insulating block 107 is a first spacing D1, and the spacing between two second insulating sub-blocks 118 in the same second insulating block 108 is a second spacing D2. The first spacing D1 is greater than the second spacing D2. In this way, compared with the extension length of the auxiliary grid 102 in the second direction Y that is interrupted by the conductive block 103, the extension length of the auxiliary grid 102 in the second direction Y that is interrupted by the main grid 101 can be increased as much as possible under the protection of the second insulating sub-block 118, so that the photo-generated carriers on more areas of the cell body 10 can be effectively collected by the auxiliary grid 102, and finally collected by the interconnector 106, thereby further improving the photoelectric conversion efficiency of the back contact photovoltaic module.

[0114] It should be noted that, Figure 14 The insulating structure in the above embodiments includes but is not limited to the insulating member 104, the first insulating block 107, and the second insulating block 108. In addition, Figure 5 The insulating structure in the above embodiments includes but is not limited to the insulating member 104, the first insulating block 107, and the second insulating block 108. In addition, Figure 1 The insulating structure in the above embodiments includes but is not limited to the insulating member 104, the first insulating block 107, and the second insulating block 108. In addition, Figure 6 , Figure 8 or Figure 11 The insulating structure in the above embodiments includes but is not limited to the insulating member 104, the first insulating block 107, and the second insulating block 108. In addition, Figure 6 The insulating structure in the above embodiments includes but is not limited to the insulating member 104, the first insulating block 107, and the second insulating block 108. In addition, Figure 1 The insulating structure in the above embodiments includes but is not limited to the insulating member 104, the first insulating block 107, and the second insulating block 108. In addition, Figure 5 The insulating structure in the above embodiments includes but is not limited to the insulating member 104, the first insulating block 107, and the second insulating block 108. In addition, Figure 8 The insulating structure in the above embodiments includes but is not limited to the insulating member 104, the first insulating block 107, and the second insulating block 108. In addition, Figure 11The extension part can be added on the insulating part based on the structure shown.

[0115] In some examples, the first distance D1 can be 1.3 mm, and the second distance D2 can be 0.42 mm.

[0116] In some examples, along the first direction X, the sub-grid 102 interrupted by the main grid 101 has multiple sub-grids, wherein the sub-grids 102 near the conductive blocks 103 on the opposite sides along the first direction X are protected by the insulating part 104, and the sub-grids 102 away from the insulating pad group are protected by the second insulating sub-block 118. A single second insulating block 108 includes two adjacent second insulating sub-blocks 118 on both sides of the main grid 101 along the second direction Y. Multiple second insulating blocks 108 can be arranged at intervals along the first direction X, and the second distance D2 between two adjacent second insulating sub-blocks 118 in the multiple second insulating blocks 108 can be gradually increased, so as to further reduce the total layout area of the second insulating sub-block 118 on the battery substrate 100.

[0117] In some examples, the battery substrate 100 is a BC battery (Back Contact), which includes but is not limited to an IBC battery (Interdigitated Back Contact), an HBC battery (Heterojunction Back Contact), a TBC battery (TOPCon Back Contact), or an HPBC battery (Hybrid Passivated Back Contact), etc. In addition, the battery substrate 100 can be a whole battery or a sliced battery. The sliced battery refers to a battery formed by a complete whole battery after a cutting process.

[0118] In some embodiments, the back contact photovoltaic module further comprises an encapsulation layer covering the surface of the cell substrate 100. The material of the encapsulation layer can be an organic encapsulation film such as a polyvinyl butyral (PVB) film, an ethylene-vinyl acetate copolymer (EVA) film, a polyolefin elastomer (POE) film, or a 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 an EVA film and a POE film stacked together, the EPE film refers to a co-extruded film formed by sequentially stacking an EVA film, a POE film, and an EVA film, and the PVP film refers to a co-extruded film formed by sequentially stacking a POE film, an EVA film, and a POE film. The co-extruded film can be prepared by extruding one or more raw materials onto another film that has been prepared, or by bonding different kinds of films together during the film processing.

[0119] In some embodiments, the back contact photovoltaic module further comprises a cover plate located on the surface of the encapsulation layer away from the cell substrate 100. The cover plate can be a glass cover plate, a plastic cover plate, or any other cover plate that has a light-transmitting function and is not easily damaged. In some embodiments, the surface of the cover plate facing the encapsulation layer can be a concave-convex surface or a suede surface containing a plurality of convex structures, thereby increasing the utilization rate of incident light.

[0120] In summary, the design of any one insulating piece 104 includes an insulating pad 114 and at least one extension piece 124. Among them, the insulating pad 114 covers at least part of the area of the main grid 101 connected with the conductive block 103, so that the insulating pad 114 not only protects part of the main grid 101 to reduce the risk of breaking the main grid 101, but also provides a higher support point for the interconnecting piece 106. In this way, on the one hand, it is helpful to avoid excessive local bending of the solder strip 136 itself; on the other hand, avoiding excessive local bending of the solder strip 136 itself is helpful to reduce the risk that the interconnecting piece 106 causes relatively large stress to the main grid 101 and the auxiliary grid 102 adjacent thereto, thereby making them prone to breakage; on the other hand, the insulating pad 114 covers the main grid 101, which is helpful to avoid the risk that the raw materials of the interconnecting piece 106 melt and drop down to the main grid 101 under high temperature conditions, and to avoid the raw materials of the interconnecting piece 106 melting under high temperature conditions causing the main grid 101 to break, thereby further reducing the risk of breaking the main grid 101. Moreover, the extension piece 124 covers part of the area of one auxiliary grid 102 disconnected by the main grid 101, which is helpful to ensure that the subsequent interconnecting piece 106 connected with the conductive block 103 will not contact the end of the disconnected part of the auxiliary grid, thereby avoiding the short circuit problem between the first auxiliary grid 112 and the second auxiliary grid 122. Further, the second width W2 of the extension piece 124 is smaller than the first width W1 of the insulating pad 114, which is helpful to reduce the amount of insulating material required to form the extension piece 124 while improving the insulation effect of the insulating piece 104 on the auxiliary grid 102 covered thereby, and to avoid the warping problem of the back contact photovoltaic module caused by the volume shrinkage of the large-area insulating material. Therefore, under the multi-faceted effects of the insulating piece 104, not only is it helpful to avoid the short circuit problem between the first auxiliary grid 112 and the second auxiliary grid 122 and effectively reduce the risk of breaking the auxiliary grid 102 or the main grid 101, but also it is helpful to reduce the bending degree of the interconnecting piece 106 itself, thereby reducing the stress generated by the interconnecting piece 106 on the cell substrate 100, and effectively improving the structural stability of the back contact photovoltaic module.

[0121] Those skilled in the art can understand that the above-mentioned embodiments are specific embodiments for implementing the present disclosure, and in actual applications, various changes can be made in form and details without departing from the spirit and scope of the embodiments of the present disclosure. Any person skilled in the art can make various modifications and changes without departing from the spirit and scope of the embodiments of the present disclosure, and therefore the protection scope of the embodiments of the present disclosure should be subject to the scope defined by the claims.

Claims

1. A back contact photovoltaic module, characterized by, The battery substrate is provided with a plurality of main grids and a plurality of sub-grids on the back surface, the main grids include first main grids and second main grids arranged alternately along a second direction, the sub-grids include first sub-grids and second sub-grids arranged alternately along a first direction, the first sub-grids are disconnected at the second main grids, and the second sub-grids are disconnected at the first main grids; A plurality of conductive blocks, each of the conductive blocks is located at the disconnected position of the first sub-grid and connected to the second main grid, or located at the disconnected position of the second sub-grid and connected to the first main grid; Insulating pieces extending along the second direction, at least two insulating pieces are respectively located on opposite sides of each of the conductive blocks along the first direction, and each of the insulating pieces includes an insulating pad and at least one extension piece, each of the extension pieces is connected to one end of the insulating pad opposite along the second direction; The insulating pad covers at least a part of the main grid connected to the conductive block, the extension piece covers at least a part of the sub-grid disconnected by the main grid, and the first width of the insulating pad is greater than the second width of the extension piece along the first direction; At least two first insulating blocks arranged along the first direction at intervals, each of the first insulating blocks includes two first insulating sub-blocks arranged along the second direction, each of the first insulating sub-blocks is located on one side of each of the conductive blocks opposite along the second direction, and covers at least a part of only one of the two branches of the sub-grid disconnected by the conductive block; and / or, at least two second insulating blocks arranged along the first direction at intervals, each of the second insulating blocks includes two second insulating sub-blocks arranged along the second direction, each of the second insulating sub-blocks covers at least a part of only one of the two branches of the sub-grid disconnected by the main grid. The insulating pad also covers at least one end of the two branches of the sub-grid disconnected by the main grid; and / or, 2. The back contact photovoltaic module of claim 1, wherein, Each of the insulating pieces includes two extension pieces connected to opposite ends of the insulating pad along the second direction. The first thickness of the insulating pad is greater than the second thickness of the extension piece along a third direction, the third direction is the thickness direction of the battery substrate body; 3. The back contact photovoltaic module of claim 1 or 2, wherein, And / or, the second thickness of the extension piece gradually decreases in the direction away from the main grid. Further comprising:

4. The back contact photovoltaic module of claim 1 or 2, wherein, At least one connection grid line extending along the first direction, one end of the connection grid line is connected to one of the sub-grids between the conductive block and the insulating piece, and the other end of the connection grid line is connected to the conductive block. At least one of the insulating pieces close to the conductive block further includes an extension part protruding towards the conductive block, and the extension part covers a part of the sub-grid between the conductive block and the insulating piece.

5. The back contact photovoltaic module of claim 1 or 2, wherein, Further comprising:

6. The back contact photovoltaic assembly of claim 5, wherein, A plurality of interconnection pieces arranged along the second direction at intervals, and each of the interconnection pieces is located on one of the main grids, and each of the interconnection pieces is connected to at least the conductive block; ​ The epitaxial part also covers a partial area of the main grid connected with the conductive block, and with a plane formed by the first direction and the second direction as a reference plane, among the epitaxial part and the interconnection corresponding to the same main grid, a normal projection of the epitaxial part on the reference plane and a normal projection of the interconnection on the reference plane have an overlap.

7. The back contact photovoltaic module of claims 1 or 2, wherein, The conductive block has an upper side and a lower side on opposite sides along the first direction, and at least two insulating pads are arranged in proximity to one of the upper side and the lower side, and the length of the at least two insulating pads in the second direction gradually decreases in a direction away from the conductive block.

8. The back contact photovoltaic module of claims 1 or 2, wherein, In a direction away from the conductive block, the thickness of the at least two insulating pads in a third direction gradually decreases. At least two insulating pads arranged in proximity to one of the opposite sides of the conductive block along the first direction are taken as a group of insulating pads, and in a single group of insulating pads, the thickness of the at least two insulating pads in a third direction gradually decreases in a direction away from the conductive block. The third direction is a thickness direction of the battery substrate body.

9. The back contact photovoltaic assembly of claim 1, wherein, In the second direction, the distance between two first insulating sub-blocks in the same first insulating block is a first distance, the distance between two second insulating sub-blocks in the same second insulating block is a second distance, and the first distance is greater than the second distance.

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