CN212695160U - Interconnection piece and solar module - Google Patents

Abstract

The utility model discloses an interconnection piece and solar module relates to the photovoltaic technology field, when guaranteeing the normal interconnection of battery piece, restraines the deformation degree of back of the body contact cell when the welding. The interconnection piece includes: the flexible welding strip comprises a flexible insulating base material and a plurality of structural welding strips arranged on the flexible insulating base material at intervals. Each structural weld strip has two welds and a connection between the two welds. The connecting parts are respectively connected with the two welding parts. At least part of the connecting part is positioned in the flexible insulating base material, and the two welding parts extend out of the flexible insulating base material. The solar cell module comprises the interconnection piece provided by the technical scheme. The utility model provides an interconnection piece is used for interconnection back of body contact battery.

Description

Interconnection piece and solar module

Technical Field

The utility model relates to the field of photovoltaic technology, especially, relate to an interconnection piece and solar module.

Background

The back contact cell is a cell in which the positive and negative electrodes of the solar cell are positioned on the back surface of the solar cell, and can be interconnected by using solder strips. The shading loss of the front grid line electrode is completely eliminated, the battery efficiency is improved, and the battery is more attractive.

However, because the positive and negative electrodes of the back contact battery are both located on the back surface of the back contact battery, and the difference between the thermal expansion coefficients of the solder strip and the battery piece is large, when the solder strip is soldered on a solder pad of the back contact battery, the solder strip expands due to heat released by soldering, and after soldering is finished, the solder strip contracts due to temperature reduction, so that the back contact battery is seriously bent and deformed, further the soldering stability is influenced, the risks of fragments and hidden cracks in the component manufacturing process are increased, and therefore, an interconnection piece capable of replacing the solder strip to realize the back contact battery is urgently needed to be searched, so that the deformation degree of the back contact battery during soldering is reduced.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an interconnection and solar module to when guaranteeing the normal interconnection of battery piece, restrain the deformation degree of back of the body contact cell when the welding.

In a first aspect, the present invention provides an interconnection, comprising: the flexible welding strip comprises a flexible insulating base material and a plurality of structural welding strips arranged on the flexible insulating base material at intervals. Each structural weld strip has two welds and a connection between the two welds. The connecting parts are respectively connected with the two welding parts. The two welding parts extend out of the flexible insulating base material, and at least part of the connecting part is positioned on the flexible insulating base material.

Under the condition of adopting above-mentioned technical scheme, a plurality of structures weld the area interval and establish on flexible insulating substrate, and connecting portion part at least is located flexible insulating substrate, and two welding parts of being connected with connecting portion stretch out flexible insulating substrate. Based on this, when the structure solder strip because the welding process, the lamination process and the produced stress of outdoor high low temperature difference, the connecting portion that the structure solder strip contains can shift the stress to flexible insulating substrate to release through flexible insulating substrate, and then reduce the degree that back contact battery takes place bending deformation, improve welding stability and long-term use stability. Simultaneously, flexible insulating substrate welds the area and plays fixed action and dustproof effect to a plurality of structures in welding process, prevents that the relative position skew of welding in-process structure welding area and pad and the produced particulate matter of welding from migrating to the battery piece openly to improve the welding accuracy.

Additionally, the utility model provides a when interconnection piece is applied to interconnection between back contact battery, interconnection piece not only can regard as perpendicular electrically conductive passageway to realize interconnection between back contact battery, can also provide the electrical isolation for two adjacent back contact batteries except that the pad region with the help of the insulating substrate of flexibility, and then reduce the electric leakage possibility, improve battery efficiency.

In one possible embodiment, each structural solder ribbon has a connecting portion with a cutout for stress relief. When the structure solder strip because the produced stress of welding process, lamination process and outdoor high low temperature difference, connecting portion not only can shift stress to flexible insulating substrate, and hollow out construction can release partial stress to further reduce the degree that back contact battery takes place bending deformation, improve welding stability and long-term stability in use.

In a possible implementation manner, the hollow structure includes at least one through hole. The pattern of each through hole is a closed pattern. At this time, the closed pattern here means that the outline pattern of the hollow structure is closed. Under the condition, the edge profile of the connecting part is complete, and the structural welding strip can be ensured to have good strength.

The pattern of each through hole is a polygonal pattern, a circular pattern, an oval pattern or a special-shaped pattern. The polygonal pattern may be triangular, rectangular, square, etc.

In a possible implementation manner, the hollow structure includes m rows of through holes, and m is an integer greater than or equal to 1. Each row of through holes comprises at least one through hole. The through holes of row 1 and row m are formed in the connection portion in any direction parallel to the connection portion.

In a possible implementation manner, the through holes in two adjacent rows are distributed in a staggered manner. At this time, the m rows of through holes of the connecting part can uniformly release the stress generated by the structural solder strip, thereby further reducing the deformation degree of the back contact battery.

In a possible implementation manner, when the through holes are slit-type through holes or rectangular through holes, if the length direction of the through holes is the distribution direction of two welding parts, the distance between two rows of through holes can be adjusted, so that the current of one welding part is transmitted to the other welding part through the connecting part in a straight line manner as much as possible, and the current loss is reduced.

In one possible implementation, m is an integer greater than or equal to 3. The number of through holes in the 1 st row of through holes and the number of through holes in the m th row of through holes are both more than or equal to 2. At this time, along the distribution direction of the 1 st row of through holes to the m th row of through holes, the number of through holes included in each row of through holes is firstly reduced and then increased.

Under the condition of adopting above-mentioned technical scheme, along the distribution direction of 1 st row through-hole to mth row through-hole, if every row of through-hole reduces earlier then increases along the length of arranging the direction, then along the distribution direction of 1 st row through-hole to mth row through-hole, the structural strength of connecting portion increases earlier then reduces, and the stress of connecting portion reduces gradually earlier then increases gradually. Based on the structure, the strength and the stress release capacity of each area of the connecting part can be adjusted by utilizing the distribution mode of the through holes in the connecting part, so that the strength and the stress release capacity of the connecting part are coordinated.

In a possible implementation manner, when m is an integer greater than or equal to 3, the number of through holes included in the 1 st row of through holes and the number of through holes included in the m th row of through holes are both greater than or equal to 1; along the distribution direction of the 1 st row of through holes to the m th row of through holes, the number of through holes included in each row of through holes is increased and then decreased.

Under the condition of adopting above-mentioned technical scheme, along the distribution direction of 1 st row through-hole to mth row through-hole, if every row of through-hole reduces earlier then increases along the length of arranging the direction, then along the distribution direction of 1 st row through-hole to mth row through-hole, the structural strength of connecting portion reduces earlier then increases, and the stress of connecting portion increases gradually earlier then reduces gradually. Based on the structure, the strength and the stress release capacity of each area of the connecting part can be adjusted by utilizing the distribution mode of the through holes in the connecting part, so that the strength and the stress release capacity of the connecting part are coordinated.

In one possible implementation, the central axes of the two welds are collinear. In this case, the current flowing from one welding portion to the other welding portion can be conducted as close to a straight line as possible.

In one possible implementation, the width of each weld is less than the maximum width of the connection. Each welding part is connected with the connecting part in an arc transition mode. When the arc transition mode is adopted for connection, stress concentration is not easy to generate at the arc transition position, so that the stress generated by the structural welding strip due to temperature change is further reduced.

In one possible implementation manner, the flexible insulating substrate is a light-shielding flexible insulating substrate. When the interconnection piece interconnects two adjacent back contact cells, if the flexible insulating base material is partially or completely positioned in the gap between the two adjacent back contact cells, the flexible insulating base material can be used as a visual shielding structure, so that the structural welding strip on the back of the solar cell module can not be seen when the solar cell module is observed from the front side, and the attractiveness of the solar cell module is improved.

In one possible implementation, at least one surface of the flexible insulating substrate is partially or entirely provided with a shielding coating. The effect of the shielding coating refers to the related description of the light shielding flexible insulating substrate, and is not described herein.

In one possible implementation manner, the flexible insulating substrate may be a single-sided tape having a release layer or a double-sided tape having a release layer.

Under the condition of adopting above-mentioned technical scheme, flexible insulating substrate can be in the same place with the bonding of back contact battery, reaches the effect of carrying out the location to the structural solder strip. And when the interconnection piece is applied to interconnection of back contact cells, if the flexible insulating base material is positioned between two adjacent back contact cells, the release layer of the single-sided adhesive tape or the double-sided adhesive tape can be used as a visual barrier layer, so that the attractiveness of the solar cell module is improved, and particulate pollution can be reduced.

In one possible implementation, each structural solder ribbon has a connection portion exposed away from a surface of the flexible insulating substrate. At this time, the solder strips of each structure can be pressed on the flexible insulating base material by adopting the pressing process and other processes.

In one possible implementation, when each structural solder ribbon has a connecting portion embedded in a flexible insulating substrate, each structural solder ribbon has a connecting portion at least partially encapsulated in the flexible insulating substrate. At the moment, the interconnection piece is of a sandwich structure, the structure welding strip can be further fixed by the flexible insulating base material, the possible displacement of the structure welding strip in the welding process is further reduced or eliminated, the possibility of connection failure of the structure welding strip and the flexible insulating base material can be eliminated under the condition that one welding part of the structure welding strip is stressed and warped, and therefore the connection stability of the structure welding strip and the flexible insulating base material is ensured.

In one possible implementation manner, the structure of the flexible insulating substrate is a strip-shaped structure. The plurality of structural welding strips are distributed at intervals along the strip-shaped extending direction of the flexible insulating base material.

In one possible implementation, each structural solder ribbon is heat pressed or bonded to the flexible insulating substrate. When each structural solder ribbon is bonded to the flexible insulating substrate by thermocompression bonding, and each structural solder ribbon is bonded to the flexible insulating substrate, the adhesive may be a polymer-based adhesive, including but not limited to one or more of polyvinyl acetate, polyvinyl acetal, acrylate, polystyrene, epoxy resin, acrylic resin, urethane resin, unsaturated polyester, butyl rubber, nitrile rubber, phenolic-polyvinyl acetal, and epoxy-polyamide.

In one possible implementation, the flexible insulating substrate has a conductive layer therein. The connection portions of the respective structural solder ribbons are electrically connected through the conductive layer. The connection portions of the respective structural solder ribbons are electrically connected through the conductive layer. The conductive layer may be a conductive strip or a layer of conductive particles of metal particles in contact with each other.

Under the condition of adopting the technical scheme, the conducting layers can electrically connect the conducting layers contained in the welding strips of each structure together, so that the conducting layers can be used as transverse conducting channels. When a welding part contained in one structural welding strip in the plurality of structural welding strips and the corresponding polar welding pad are in poor welding, the structural welding strip is used as a local failure of the vertical conductive channel, but the structural welding strip can also conduct current to other structural welding strips with good welding by utilizing the conductive layer, so that the problem of reduction of battery efficiency when the vertical conductive channel is in local failure is avoided, and the connection reliability of the interconnection piece is improved.

In a second aspect, the present invention further provides a solar cell module, which includes at least two cells and a plurality of interconnections for interconnecting the cells, wherein each interconnection is the interconnection described in the first aspect or any one of the first aspects. The back surface of each cell piece is provided with two polarity pads. Each polarity pad includes a bonding portion that is bonded to a corresponding structural bonding strip included in the corresponding interconnect.

In one possible implementation, a gap is formed between two adjacent battery plates. If corresponding interconnection pieces are accommodated in the gap, two polarity pads on the back of each battery piece are close to the edge of the battery piece, different polarity pads of two adjacent battery pieces are close to the same gap, and the interconnection pieces corresponding to the different polarity pads of two adjacent electrode pieces are the same interconnection piece, so that the interconnection of two adjacent battery pieces is realized by one interconnection piece.

In a possible implementation manner, the solar cell module further includes at least one bus bar. Each bus bar is welded to a weld contained in a plurality of structural weld strips provided with the interconnect. In this case, the bus bars and the interconnections may collect and conduct the current generated from the battery cells.

In a possible implementation manner, when the bus bar is located between two adjacent battery pieces, the interconnection pieces corresponding to the pads with different polarities of the two adjacent electrode pieces are different interconnection pieces, and the interconnection pieces corresponding to the pads with different polarities of the two adjacent battery pieces share one bus bar, so that the two adjacent battery pieces are welded by using the two interconnection pieces and one bus bar.

In one possible implementation manner, when the plurality of battery pieces are located on the same side of the bus bar and the pads with the same polarity of the plurality of battery pieces are close to the bus bar, the bus bar may be used to weld the welding parts included in the corresponding interconnection pieces of the pads with the same polarity of the plurality of electrode pieces on the bus bar, so that the plurality of battery pieces are connected in parallel by one bus bar.

In a possible implementation manner, the solar cell module further comprises a visual shielding layer located between two adjacent cell sheets, and the visual shielding layer is located on a surface of the at least one interconnection piece facing the front side of the cell sheets. At this time, if the insulating flexible substrate included in the interconnection member is transparent, the structural solder strip may be shielded by the visual shielding layer, so that the solar cell module has an attractive appearance.

In a possible implementation manner, the welding part is welded on the corresponding polar welding pad of the battery piece by adopting an electromagnetic or infrared welding mode.

The beneficial effects of the second aspect or any possible implementation manner of the second aspect are the same as the beneficial effects of the first aspect or any possible implementation manner of the first aspect, and are not described herein again.

Drawings

The accompanying drawings, which are described herein, serve to provide a further understanding of the invention and constitute a part of this specification, and the exemplary embodiments and descriptions thereof are provided for explaining the invention without unduly limiting it. In the drawings:

fig. 1 is a schematic structural diagram of a solar cell module according to an embodiment of the present invention;

fig. 2A to fig. 2C are schematic views of welding structures of different numbers of battery pieces and interconnection pieces according to an embodiment of the present invention;

fig. 3A and fig. 3B are schematic diagrams of two back structures of a battery cell in an embodiment of the present invention;

fig. 4A to fig. 4C are schematic back structure diagrams of three battery string sets provided in an embodiment of the present invention;

fig. 4D is a schematic front view of the battery string shown in fig. 4C;

fig. 5 is a schematic view of a battery slice in an embodiment of the present invention;

fig. 6 is a schematic diagram of a basic structure of an interconnection component according to an embodiment of the present invention;

fig. 7A and 7B are schematic diagrams of two basic structures of a structural solder strip in an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a flexible insulating substrate according to an embodiment of the present invention;

fig. 9A is a schematic view of an exemplary interconnection structure according to an embodiment of the present invention;

fig. 9B is a schematic view of another exemplary interconnection structure according to an embodiment of the present invention;

fig. 10A is a schematic view of another exemplary interconnection structure according to an embodiment of the present invention;

FIG. 10B is a cross-sectional view of the interconnect of FIG. 10A in the direction A-A;

FIG. 10C is another cross-sectional view of the interconnect shown in FIG. 10A in the direction A-A;

fig. 11A to 13A are schematic diagrams illustrating three distributions of multiple rows of through holes distributed along a first direction according to an embodiment of the present invention;

fig. 11B-13B are schematic diagrams illustrating three distributions of multiple rows of through holes distributed along the second direction according to an embodiment of the present invention;

fig. 14 is a schematic structural diagram of an apparatus for manufacturing an interconnection according to an embodiment of the present invention;

fig. 15 is a schematic structural flow chart of a method for manufacturing an interconnection according to an embodiment of the present invention.

Detailed Description

In order to make the technical problem, technical solution and advantageous effects to be solved by the present invention more clearly understood, the following description is given in conjunction with the accompanying drawings and embodiments to illustrate the present invention in further detail. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise. The meaning of "a number" is one or more unless specifically limited otherwise.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

Fig. 1 illustrates a schematic structural diagram of a solar cell module according to an embodiment of the present invention. As shown in fig. 1, a solar module provided in an embodiment of the present invention may include a battery module Cell. In addition to the battery module Cell, the solar Cell module may also include a package back sheet BP, a package cover sheet TP, and one or two common adhesive layers. For example: the battery module Cell is located between the package cover plate TP and the package back plate BP, a first bonding layer J1 is provided between the package cover plate TP and the battery module Cell, and a second bonding layer J2 is provided between the package back plate BP and the battery module Cell. As the material of the adhesive layer, a material such as ethylene-vinyl acetate copolymer (EVA) is generally selected, but not limited thereto.

Fig. 2A to fig. 2C illustrate schematic diagrams of welding structures of different numbers of battery pieces and interconnections according to embodiments of the present invention. As shown in fig. 2A to 2C, the battery module Cell shown in fig. 1 includes at least two battery cells 100 and a plurality of interconnections 200 for interconnecting the battery cells 100. These battery cells 100 and interconnections 200 may constitute a battery module Cell shown in fig. 1.

Fig. 3A and fig. 3B are schematic diagrams of two back structures of a battery cell in an embodiment of the present invention. As shown in fig. 3A and fig. 3B, when each of the battery slices 100 is a back contact battery, the front surface of each of the battery slices 100 may not be shielded by any grid lines, or there may be some fine grid lines, and the back surface of each of the battery slices 100 has main grid lines, which can lead out holes and electrons. Based on this, as for the kind of the cell sheet 100, there may be an Interdigitated back contact (abbreviated as IBC cell), a Metal Wrap Through (MWT) silicon solar cell, an Emitter Wrap Through (EWT) silicon solar cell, etc., but not limited thereto.

As shown in fig. 3A and 3B, in order to simultaneously lead out holes and electrons on the back surface of the battery piece 100, the back surface of the battery piece 100 has two polarity pads, namely a first polarity pad 101 and a second polarity pad 102. When the first polarity pad 101 is a positive electrode pad, the second polarity pad 102 is a negative electrode pad. When the first polarity pad 101 is a negative electrode pad, the second polarity pad 102 is a positive electrode pad. In practical applications, the back surface of the battery piece 100 has a positive polarity region such as a P-type region and a negative polarity region such as an N-type region. The positive region may be used to lead out holes, the positive pad may be formed in the positive region, the negative region may be used to lead out electrons, and the negative pad may be formed in the negative region.

As shown in fig. 3A and 3B, in order to reduce the influence of stress generated by the interconnection 200 during the cold and hot (soldering process or external environment) on the battery piece 100, the pads of two polarities included in the same battery piece 100 are close to the edge of the battery piece 100. Specifically, the battery cell 100 has a first side edge C1 and a second side edge C2. The first polarity pads 101 are formed on the rear surface of the battery sheet 100 near the first side edge C1, and the second polarity pads 102 are formed on the rear surface of the battery sheet 100 near the second side edge C2. The first side edge C1 and the second side edge C2 may be opposite to each other or may intersect each other, as long as they are oriented in different directions.

For example, as shown in fig. 3A and 3B, the first side edge C1 and the second side edge C2 are oppositely disposed. The first side edge C1 may be one long side of the cell sheet 100, and the second side edge C2 may be the other long side of the cell sheet 100.

As shown in fig. 3A and 3B, the number of the first polarity pads 101 and the number of the second polarity pads 102 may be one or more for the same battery piece 100. When the number of first polarity pads 101 and the number of second polarity pads 102 are plural, each first polarity pad 101 and the corresponding second polarity pad 102 may be disposed in a collinear manner (collinear with respect to the imaginary line X) as shown in fig. 3A, or may be disposed in a misaligned manner (misaligned with respect to the imaginary line X) as shown in fig. 3B.

As shown in FIGS. 3A and 3B, the minimum distance d between each polarity pad and the edge of the cell may be 0-10 mm. A minimum distance d between the second polarity pad and the second side edge is illustrated in fig. 3A and 3B. When d is 0mm, the side of the second polarity pad 102 close to the edge of the cell is flush with the second side edge C2. When d is larger than 0 and is less than or equal to 10mm, a gap (with the width of d) is formed between one side, close to the edge of the battery piece, of the second polarity bonding pad 102 and the second battery piece edge C2, so that the influence of stress generated in the welding process on the edge of the battery piece can be reduced.

Each polarity pad may be soldered to a respective interconnect. The interconnect to which each polarity pad is bonded is defined herein as the interconnect corresponding to that polarity pad. Welding means include, but are not limited to, electromagnetic or infrared welding means. The shape of each polar pad can be rectangular, circular, oval or other shapes, and can be selected according to actual conditions. As for the size of each polarity pad, it may be 0.5mm-5mm (the largest radial dimension of the pad, for example, when the positive electrode pad is a circular pad, the largest radial dimension of the pad of the circular pad is the diameter of the circular pad, and, for example, when the positive electrode pad is an oval pad, the largest radial dimension of the pad of the oval pad is the major axis of the oval pad), so that each polarity pad has enough bonding area for bonding with the corresponding interconnect. When bonding the polarity pads and the corresponding interconnections, the interconnections may be bonded to the corresponding polarity pads by electromagnetic or infrared bonding. For example: when the welding mode of the polar welding pad and the interconnecting piece is electromagnetic welding, the welding temperature is 180-380 ℃, and the welding time is 1000-4000 ms.

In one example, as shown in fig. 2A, for the same interconnect 100, the interconnect 200 bonded to the first polarity pad 101 is defined as a first interconnect 200A corresponding to the first polarity pad 101, and the interconnect 200 bonded to the second polarity pad 102 is defined as a second interconnect 200B corresponding to the second polarity pad 102.

In another example, as shown in fig. 2B and 2C, for two adjacent battery pieces, the battery pieces corresponding to the pads with different polarities of the two adjacent battery pieces may be the same interconnection piece 200 or different interconnection pieces 200. Two adjacent battery pieces may be defined as a first battery piece 100A and a second battery piece 100B. The first cell piece 100A and the second cell piece 100B have a gap therebetween. The void receives a corresponding interconnect 200 therein (i.e., the void between the first cell piece 100A and the second cell piece 100B corresponds to the interconnect 200).

As shown in fig. 2B and 2C, when the first polarity pad 101 and the second polarity pad 102 on the back surface of the first cell 100A and the back surface of the second cell 100B are both close to the cell edge, and the pads with different polarities on the first cell 100A and the second cell 100B are close to the same gap. In practical applications, when the first polarity pads 101 and the second polarity pads 102 of the first cell piece 100A and the second cell piece 100B are disposed opposite to each other, the first polarity pads 101 of the first cell piece 100A and the second polarity pads 102 of the second cell piece 100B are close to the gap between the first cell piece 100A and the second cell piece 100B.

If the cell pieces corresponding to the pads with different polarities of two adjacent cell pieces are the same interconnection piece, as shown in fig. 2B, the first polarity pad 101 of the first cell piece 100A and the second polarity pad 102 of the second cell piece 100B are welded by the same interconnection piece 200. At this time, the interconnection of the first polarity pads 101 of the first cell piece 100A and the second polarity pads 102 of the second cell piece 100B is achieved using the same interconnection piece 200.

If the cells corresponding to the pads with different polarities of two adjacent cells are different interconnections, as shown in fig. 2C, the interconnection corresponding to the first polarity pad 101 of the first cell 100A is the first interconnection 200A, the interconnection corresponding to the second polarity pad 102 of the second cell 100B is the second interconnection 200B, and both the end of the first interconnection 200A away from the first cell 100A and the end of the second interconnection 200B away from the second cell 100B are welded to the bus bar 300. At this time, the first and second interconnections 200A and 200B share one bus bar 300, and the first and second interconnections 200A, 300 and 200A may constitute an interconnection assembly to connect the first and second battery cells 100A and 100B in series.

Fig. 4A to fig. 4C illustrate schematic back structures of three battery string sets provided by an embodiment of the present invention. As shown in fig. 4A to 4C, the solar cell module may further include at least one bus bar 300. Each of the bus bars 300 may be welded with the corresponding interconnection piece 200 to achieve the interconnection of the battery cells 100. In practical applications, the bus bar 300 may be welded to the corresponding interconnection piece 200 in advance, and then the end of the interconnection piece 200 away from the bus bar 300 is welded to the corresponding polarity pad, or the end of the interconnection piece 200 may be welded to the corresponding polarity pad first, and then the bus bar 300 is welded to the end of the interconnection piece 200 away from the corresponding polarity pad.

In one example, as shown in fig. 4A, two of the battery strings may be welded together in series to form a battery string, and then 2 battery strings are connected together in parallel by using the bus bar 300 to form a battery string set. For example: in the half cells (4 in total) in 2 rows and 2 columns, two cells 100 contained in each column of cells are connected in series through the interconnection member 200 to form a cell string, and then the 2 cell strings are connected in parallel by the bus bar 300 to form a cell string group shown in fig. 4A.

In another example, as shown in fig. 4B, a group of 4 battery strings may be welded together to form a battery string, and then the battery strings are connected in parallel by using the bus bar 300 to form a battery string group. For example: in the half cells (total 8) in 4 rows and 2 columns, in each column of the cells, every two cells 100 are connected in series through the interconnection piece 200 to form a cell string, and then 2 cell strings are connected in parallel through the bus bar 300 to form a cell string group shown in fig. 4B.

In yet another example, as shown in fig. 4C, two battery plates 100 may be grouped together and connected in series to form a battery string, and then the battery strings are connected in series and parallel according to a designed circuit to form a battery string group. For example: in the half cells (24 cells in total) in 4 rows and 6 columns, in each column of the cell 100, two cell 100 are first connected in series by the interconnection member 200 to form 1 cell string, and then 12 cell strings are interconnected by two interconnection bars and the bus bar 300 connecting the two interconnection bars to form the cell string group shown in fig. 4C.

As shown in fig. 4C, when the interconnection member 200 interconnects two adjacent battery cells 100, a gap is formed between the two adjacent battery cells 200. The voids receive corresponding interconnections 200 therein. To enhance the visual impact of the assembly, fig. 4D illustrates a front schematic view of the battery string shown in fig. 4C. As shown in fig. 4D, the solar cell module further includes a visual barrier layer 400 between the two adjacent cell sheets 100. The visual barrier layer 400 is located on the surface of the at least one interconnection piece 200 facing the front side of the cell sheet. At this time, the visual shielding layer 400 can scatter the sunlight irradiated on the visual shielding layer to the surrounding cell, so as to improve the light utilization rate of the cell. The adhesive layer (e.g., the second adhesive layer J2 shown in fig. 1) used in the solar cell module is a polymer material that is susceptible to discoloration due to aging, and examples thereof include: when the EVA is in long-term contact with a Cu material or other materials, the EVA is easy to turn brown, and the influence of EVA discoloration on the appearance of the solar cell module can be effectively reduced by utilizing the visual shielding layer 400.

In an actual assembly process, as shown in fig. 4D, the visual shielding layer 400 may be attached to the interconnection member 200, and then the interconnection member 200 and the corresponding polar pad are welded together, so that the visual shielding layer 400 faces the surface of the front surface of the cell 100, thereby achieving the purpose of shielding interconnection and ensuring a good appearance of the solar cell module. For example: the material of the visual barrier layer 400 may be a light-shielding material, and the color of the material may be similar to or the same as the color of the back sheet of the solar cell module. For example: when a white backboard is adopted, the color of the used visual shielding layer is white, and when a black backboard is adopted, the color of the used visual shielding layer is black.

The battery piece 100 shown in fig. 4A to 4C may be the full battery piece BA shown in fig. 5, or may be a sliced battery piece. Fig. 5 illustrates a schematic slicing diagram of a battery plate in an embodiment of the present invention. As shown in fig. 5, the sliced battery pieces can be cut from a whole battery piece BA, and the cutting process can be implemented by using an existing cutting process. The sliced battery piece is a 1/N sliced battery piece, and N is the number of battery pieces formed after a complete battery piece BA is cut. For example: forming a dicing street H on the full cell BA and cutting the full cell BA along the dicing street H, two cell pieces 100 defined as half cell pieces may be formed. Of course, the complete cell BA may also be cut into more sub-cells with substantially the same area, which is not described herein again.

When the sliced cells are interconnected by using the interconnection pieces 200 shown in fig. 4A to 4C to form a solar cell module, the cells in the solar cell module are often interconnected by using a series-parallel structure, so as to ensure that the current of each main grid is reduced to 1/2, the internal loss is reduced to 1/4 of the whole cell, and further the power of the module is improved. However, the reduction of the cell area can reduce the resistance loss of the interconnection and improve the energy output efficiency, but there are many cutting damages, which may adversely affect the cell performance, so that the cutting and series design needs to be decided after comprehensive trade-off. For example: when a plurality of sliced battery pieces are connected in series and in parallel, the solar photovoltaic module can have higher output voltage, a plurality of battery pieces can be connected in series, and the number of the battery pieces is not limited and is determined according to actual requirements.

In one example, the back side of the cell can be designed for Multi-Bus Bar (MBB). The MBB design can shorten the conduction distance of current on the fine grid, shorten the current collection path of the battery by more than 50%, reduce the loss of transverse resistance, reduce the packaging loss and enable the component to have higher efficiency.

The number of the main gates of the multi-main gate is mainly determined by the balance of electricity and optics, and the series resistance can be reduced by increasing the number of the main gates, but the light shielding area is correspondingly increased. Based on this, the number of pads of each polarity may be 6BB to 15 BB. The pad may be rectangular in shape, preferably 2mm by 3mm in size. The minimum distance between each polar pad and the edge of the corresponding cell can be 3mm to prevent the cell from splitting caused by excessive stress.

In order to improve cell efficiency, a thinner main grid can be selected for MBB design plus die cell design. For example: the battery piece can be a rectangular 9BB half IBC battery. At this time, the back surface of the IBC cell has two opposite long sides (i.e., the first and second opposite side edges), 9 first polarity pads are spaced apart along the length and adjacent to one long side, and 9 second polarity pads are spaced apart along the length and adjacent to the other long side. Compared with other grid lines, the 9BB half IBC battery has the advantages of high efficiency and low welding process difficulty.

In order to realize the interconnection of above-mentioned back contact battery, the embodiment of the utility model provides a pair of interconnection piece to alleviate the produced stress of welding process and outdoor high low temperature difference, and then reduce the degree that back contact battery takes place bending deformation, improve welding stability and accuracy.

Fig. 6 illustrates a basic structure diagram of an interconnection component according to an embodiment of the present invention. As shown in fig. 6, an interconnection piece provided by an embodiment of the present invention includes: a flexible insulating substrate 210, and a plurality of structural solder strips 220 formed on the flexible insulating substrate 210.

As shown in fig. 6, the plurality of structural solder strips 220 may be disposed on the flexible insulating base material 210 at intervals, and the structure of the flexible insulating base material 210 may be a strip-shaped structure, such that the plurality of structural solder strips 220 are spaced apart along the strip-shaped extending direction of the flexible insulating base material 210.

When a cell has certain polarity pads that are soldered to a corresponding interconnect, the number of corresponding polarity pads of the interconnect is related to the number of structural solder ribbons that the interconnect contains. For example: in the battery cell shown in fig. 4A, the number of the first polarity bonding pads 101 and the second polarity bonding pads 102 is 9, and the number of the structural bonding tapes 220 provided on the flexible insulating base material 210 may be 9, but may also be less than 9, or more than 9, so as to meet different circuit design requirements. Based on this, when a battery piece is provided with certain polarity welding pads which are welded with corresponding interconnection pieces, each polarity welding pad contained in each polarity welding pad is welded with a corresponding structural welding strip contained in the corresponding interconnection piece.

Compared with the traditional interconnection solder strip, the plurality of structural solder strips 220 shown in fig. 6 are arranged on the flexible insulating base material 210 at intervals, so that the use amount of solder strip materials can be reduced, the manufacturing cost can be reduced, the contact area between the structural solder strips 220 contained in the interconnection piece and the back surface of the cell piece is reduced, the influence of thermal stress during interconnection is reduced, and the reliability of the solar cell module is improved. More importantly, when a plurality of structural solder strips 220 are spaced apart from one another on the flexible insulating substrate 210, the formed interconnection has good flexibility, so that the structural solder strips 220 can release thermal stress caused by high and low temperature differences (such as welding process, lamination process and outdoor environment change) through the flexible insulating substrate 210, thereby reducing the degree of bending deformation of the back contact battery, and improving welding stability and long-term use stability. And simultaneously, the embodiment of the utility model provides an when interconnection piece is applied to interconnection between back contact battery, flexible insulating substrate 210 that interconnection piece includes can provide the electrical isolation for two adjacent back contact batteries except that the pad region, and then reduces the electric leakage possibility, improves battery efficiency. That is, the flexible insulating substrate 210 can prevent the structural solder strip 220 and the cell from forming a shunt path in an area where the cell is not required to be interconnected, thereby improving the cell conversion efficiency.

In addition, as shown in fig. 6, when the interconnection piece and the corresponding polar pad are welded, the flexible insulating base material 210 may fix the plurality of structural solder strips 220 during the welding process, so as to prevent the structural solder strips 220 from deviating from the pad in the welding process, thereby improving the welding accuracy, and preventing the structural solder strips 220 from being electrically short-circuited when the structural solder strips 220 are not aligned with the pad. Also, as shown in fig. 2A to 2C, when the interconnection piece 200 is located at a space between two adjacent battery cells or at one side of a battery cell, the flexible insulating base material 210 shown in fig. 6 may be partially or entirely located at one side of the space or the battery cell. If the flexible insulating substrate 210 is partially located at one side of the gap or the cell piece, the region of the flexible insulating substrate 210 that is not located at one side of the gap or the cell piece may be attached to the edge of the cell piece.

When the interconnection piece is located in a gap between two adjacent battery pieces or on one side of a battery piece, the flexible insulating base material 210 shown in fig. 6 can shield the gap at the edge of the battery piece, so that the possibility that particles generated in the welding process migrate to the front side of the battery piece through the edge of the battery piece is reduced, and the pollution of the particles to the front side of the battery piece in the welding process, the subsequent process or the using process is further reduced. In addition, the flexible insulating substrate 210 can also be used as a spacing mark of the back contact cell, so that the assembly symmetry and the aesthetic property of the solar cell module are realized.

In the alternative, as shown in FIG. 6, the structural weld beads 220 may be formed using a stamping process, a chemical etching process, an electrical discharge machining process, a laser cutting process, or other suitable manufacturing process. The plurality of structural solder strips 220 are spaced apart on the flexible insulating substrate, which not only allows for the fabrication of interconnects with superior strain relief capabilities, but also allows for lower fabrication costs. The original solder strip for manufacturing the structural solder strip can be 0.02mm-0.3mm in thickness and 3mm-7mm in width. For example: the original solder strip is made of copper-based materials such as oxygen-free copper or T2 red copper, the copper content is more than or equal to 99.99 wt%, and the electric conductivity is more than or equal to 98%. The solder strip is a double-sided coating, the coating material is Sn63Pb37, the thickness of the coating is 0.02-0.1mm, and the melting point of the coating is about 183 ℃. The tensile strength of the welding strip is more than or equal to 150N/mm²The elongation at break is more than or equal to 20 percent, and the yield strength is less than or equal to 65 MPa.

As shown in fig. 6, each of the structural solder strips 220 may be formed on the flexible insulating substrate 210 by thermal pressing or bonding, so that the structural solder strips 220 form an integral interconnection with the flexible insulating substrate 210. When each structural bonding strip 220 is adhesively formed on the flexible insulating substrate 210, the flexible insulating substrate 210 may be an insulating polymer material. The polymer material includes one or more of polyvinyl butyral (PVB), Polyolefin (POE), Ethylene Vinyl Acetate (EVA), but is not limited thereto. The binder may be a polymer binder, including but not limited to one or more of polyvinyl acetate, polyvinyl acetal, acrylate, polystyrene, epoxy, acrylic, urethane, unsaturated polyester, butyl rubber, nitrile rubber, phenolic-polyvinyl acetal, and epoxy-polyamide.

In one example, as shown in fig. 6, when there is a gap between two adjacent battery pieces and the interconnection piece is accommodated in the gap, the flexible insulating substrate 210 included in the interconnection piece may be a light-shielding flexible insulating substrate or a transparent flexible insulating substrate. If the flexible insulating base material 210 contained in the interconnection piece is a shading flexible insulating base material, the flexible insulating base material 210 is partially or completely positioned in a gap between two adjacent back contact cells, so that the flexible insulating base material 210 can be used as a visual shielding structure, and the structural solder strip 220 on the back of the solar cell module cannot be seen when the solar cell module is observed from the front, so that the attractiveness of the solar cell module is improved.

As shown in fig. 6, when the flexible insulating substrate 210 is a light-shielding flexible insulating substrate, especially a transparent flexible insulating substrate, in order to improve the visual effect, on one hand, the foregoing visual shielding layer may be attached to the surface of the flexible insulating substrate 210 that needs to face the front side of the battery cell, so as to shield the structural solder strip 220; on the other hand, the flexible insulating substrate 210 may be improved.

For example: the surface of the flexible insulating substrate is partially or entirely provided with a shielding coating. The shielding coating can be positioned on one side of the flexible insulating base material and also can be positioned on two sides of the flexible insulating base material, so that the flexible insulating base material has a good light shielding effect. The color of the blocking coating can be referred to the color of the above visual blocking layer, and the effect can also be referred to the related description of the above visual blocking layer.

Another example is: the flexible insulating substrate is a single-sided tape with a release layer or a double-sided tape with a release layer. The release layer can reduce the pollution of the environment or the operation table top to the surface of the adhesive tape in the processing process of the solar cell module.

In an application scenario, as shown in fig. 4A to 4D and fig. 6, when the interconnects are soldered to the corresponding polar pads, if the flexible insulating substrate 210 is located between two adjacent battery pieces 100, the surface of the flexible insulating substrate 210 facing the front side of the battery pieces may have a release layer. The color of the release layer can refer to the color of the visual shielding layer, and the effect can also refer to the related description of the visual shielding layer. Meanwhile, in the area where the flexible insulating substrate 210 faces the back side of the battery piece (i.e., the surface where the plurality of structural solder strips 220 are formed), the flexible insulating substrate 210 is located between two adjacent structural solder strips 220, and a release layer may also be formed to prevent particulate contamination (from component processing or subsequent use).

In an application scenario, one sticky side of a single-sided tape can be attached to the edge of two adjacent battery pieces close to the same gap, so that the sticky side of the single-sided tape faces the front side of the battery pieces, and then the structural solder strip is welded on the corresponding polar pad. At the moment, the single-sided adhesive tape serves as a flexible insulating base material to play a role in positioning before welding, so that the position of the structural welding strip is not easy to shift when the structural welding strip is welded. Of course, for the double-sided adhesive tape, any side is only required to be attached to the edge of the two adjacent battery pieces close to the same gap. And will not be described in detail herein.

Fig. 7A and 7B illustrate two basic structural diagrams of the structural solder strip in the embodiment of the present invention. As shown in fig. 7A and 7B, each structural solder strip 220 has two solder portions and a connecting portion 221 between the two solder portions. The connection portions 221 are connected to the two welding portions, respectively. The connecting portion 221 is at least partially located on the flexible insulating substrate 210. The two welds extend beyond the flexible insulating substrate. For example: each weld may be a solid plane, and the two welds may extend out of the flexible insulating substrate 210 in opposite directions.

When each polarity bonding strip of the battery piece is welded with the structural bonding strip corresponding to the corresponding interconnection piece, each polarity bonding strip contained in each polarity bonding strip is welded with one welding part contained in each structural bonding strip contained in the interconnection piece. The welding method includes, but is not limited to, electromagnetic or infrared welding on the corresponding polar welding pads of the battery plate. And in the welding, laminating or follow-up use process, if the welding part generates thermal stress, the thermal stress can be transferred to the flexible insulating base material through the connecting part, and the thermal stress is released by utilizing the flexibility of the flexible insulating base material, so that the bending deformation degree of the back contact battery is reduced, and the welding stability and the long-term use stability are improved.

Specifically, as shown in fig. 7A and 7B, the two welding portions include a first welding portion 221A and a second welding portion 221B. The first and second soldering parts 221A and 221B are each used for soldering with a corresponding polarity pad. For example: when the first welding part 221A is welded to the first polarity pad, the second welding part 221A is used to conduct current, which may be welded to the bus bar or the second polarity pad of another cell.

As shown in fig. 6, 7A and 7B, when each of the structural solder strips 220 is formed on the flexible insulating base material 210 by thermal compression, and the thickness of the flexible insulating base material 210 is as thin as possible, for example, the thickness of the flexible insulating base material 210 is less than 0.02mm, the bending degree of the first solder part 221A and the second solder part 221B can be reduced, so that the first solder part 221A and the second solder part 221B can be soldered to the corresponding polar pads in a horizontal manner as possible, thereby improving the soldering reliability. Of course, if the flexible insulating substrate 210 is selected to have thermoplastic properties, the flexible insulating substrate 210 may expand to some extent in the lamination process under the lamination thermal field environment, so that the flexible insulating substrate 210 may fill between two adjacent battery plates, thereby completely blocking the gap between the two adjacent battery plates, but will not extend to the back regions of the battery plates, which may affect the power generation of the battery plates. In addition, the thickness of the structural solder strip 220 is less than or equal to 1/3 of the thickness of the flexible insulating base material 210, so as to avoid the problem that the structural solder strip 220 cuts off the flexible insulating base material 210 due to excessive hot-pressing pressure during the hot-pressing process. Based on this, the original solder strip thickness may be 0.12mm, with a width of preferably 5 mm.

In one example, as shown in fig. 7A and 7B, the central axes of the first and second welding portions 221A and 221B may be arranged in line. When the first welded part 221A and the second welded part 221B are defined as rectangular shapes, the axis of the first welded part 221A and the second welded part 221B along the longitudinal direction thereof is the central axis. In this case, the current flowing from the first welded portion 221A to the second welded portion 221B can be conducted as close to a straight line as possible.

In one example, as shown in fig. 7A and 7B, the width of the first welding part 221A and the width of the second welding part 221B may each be smaller than the maximum width of the connection part 221. For example: when the first welding part 221A, the second welding part 221B, and the connection part 221 are all rectangular structures, the first welding part 221A and the second welding part 221B may have a size of 6 × 1mm, and the connection part 221 may have a size of 6 × 3 mm. At this time, the width of each of the first welding portion 221A and the second welding portion 221B is 1mm, and the width of the connecting portion 221 is 3 mm.

In one example, the first weld 221A and the second weld 221B shown in fig. 7A and 7B and the connection 221 are each connected in a right angle transition as shown in fig. 7A or an arc transition as shown in fig. 7B. When connected in an arc transition manner as shown in fig. 7B, stress concentration is not easily generated at the arc transition, thereby further reducing stress generated by the structural solder strip 220 due to temperature change (soldering temperature change or external environment temperature change).

As shown in fig. 2A, 7A and 7B, in the same cell, the first welding portion 221A included in the first interconnection 200A is welded to the first polarity land 101 included in the cell 100, and the second welding portion 221B included in the second interconnection 200B is welded to the second polarity land 102 included in the cell 100.

For two adjacent battery pieces, if the battery pieces corresponding to the different polarity pads of the two adjacent battery pieces are the same interconnection piece, as shown in fig. 2B, 7A and 7B, the same interconnection piece 200 includes a first welding portion 221A of each structural welding strip welded to each first polarity pad 101 of the first battery piece 100A in a one-to-one correspondence manner, and a second welding portion 221B of each structural welding strip welded to each second polarity pad 102 of the second battery piece 100B in a one-to-one correspondence manner. If the battery pieces corresponding to the pads having different polarities of the adjacent two battery pieces are different interconnections, as shown in fig. 2C, 7A and 7B, the first welding portion 221A of each structural bonding tape included in the first interconnection 200A is welded to each first polarity pad 101 of the first battery piece 100A in a one-to-one correspondence, the second welding portion of each structural bonding tape included in the second interconnection 200B is welded to each second polarity pad 102 of the second battery piece 100B in a one-to-one correspondence, and the bus bar 300 is welded to the second welding portion 221B of each structural bonding tape included in the first interconnection 200A and the first welding portion 221A of each structural bonding tape included in the second interconnection 200B, respectively.

Fig. 8 illustrates a schematic structural diagram of a flexible insulating substrate according to an embodiment of the present invention. As shown in fig. 8, the flexible insulating substrate 210 has a conductive layer 212 therein. In fig. 7A and 7B, the connection portion 221 provided in each of the structure lands 220 is electrically connected by the conductive layer 212. It should be understood that the conductive layer 212 of fig. 8 is partially exposed, but in practical cases, the exposed conductive layer 212 of fig. 8 is typically embedded by the flexible insulating substrate 210 to reduce unnecessary contamination and loss.

As shown in fig. 8, the conductive layer 212 may be a conductive strip or a conductive particle layer formed of metal particles in contact with each other. The conductive strip may be one or more of a copper strip, a silver strip, an aluminum strip, etc., and the layer of conductive particles may include one or more of copper particles, silver particles, aluminum particles, etc., in contact with each other. In practical applications, the conductive particle slurry may be formed on one side of the flexible insulating layer, and the solvent contained in the flexible insulating substrate 210 may be removed (for example, low temperature drying) without damaging the flexible insulating substrate, so as to form the conductive particle layer. Then, another flexible insulating substrate 210 is covered on the surface of the flexible insulating layer where the conductive particle layer is formed, so that the conductive particle layer is formed in the flexible insulating substrate.

Based on the above structure, as shown in fig. 7A, 7B and 8, when the conductive layer 212 electrically connects the connection portions 221 included in the respective structure bonding pads 220 together, the conductive layer 212 can be used as a transverse conductive path. When poor welding occurs between the first welding part 221A contained in one structural welding strip 220 of the plurality of structural welding strips 220 and the first polarity welding pad, the structural welding strip 220 serves as a local failure of the vertical conductive channel, but the structural welding strip 220 can also conduct current to other well-welded structural welding strips 220 by utilizing the conductive layer, so that the problem of reduction of the battery efficiency when the vertical conductive channel is locally failed is avoided, and the connection reliability of the interconnection is improved.

Fig. 9A illustrates an exemplary interconnection structure in an embodiment of the present invention. Fig. 9B illustrates another exemplary interconnection structure in an embodiment of the present invention. As shown in fig. 9A and 9B, each of the structural solder strips 220 has a connecting portion 221 exposed away from the surface of the flexible insulating base material 210. At this time, the plurality of structural solder strips 220 may be placed on the surface of the flexible insulating substrate 210, and the plurality of structural solder strips 220 may be pressed on the flexible insulating substrate 210 under pressure.

As shown in fig. 9A and 9B, when the flexible insulating substrate 210 has the conductive layer 212 therein, the flexible insulating substrate 210 includes two flexible insulating layers 211 and the conductive layer 212 between the two flexible insulating substrates 211. At this time, when the plurality of structural solder strips 220 are pressed on one surface of the flexible insulating substrate 210 by using a hot pressing process, the pressure can be controlled, so that the bottoms of the connecting portions 221 included in the structural solder strips 220 are in contact with the conductive layer 212.

Fig. 10A illustrates another exemplary interconnection structure in an embodiment of the present invention. Figure 10B illustrates a cross-sectional view of the interconnect shown in figure 10A in the direction a-a. As shown in fig. 10A and 10B, each of the structural solder strips 220 has a connecting portion 221 embedded in the flexible insulating base material 210. Each structural solder ribbon 220 has a connecting portion 221 at least partially encased within a flexible insulating substrate 210. The first welding part 221A and the second welding part 221B protrude from two opposite directions of the flexible insulating base material 210. At this time, the interconnection shown in fig. 10A is a sandwich structure, and the structural solder strip 220 can be further fixed by the flexible insulating base material 210, which not only further reduces or eliminates the displacement of the structural solder strip 220 that may occur during the soldering process, but also eliminates the possibility of connection failure between the structural solder strip 220 and the flexible insulating base material 210 under the condition that one soldering portion of the structural solder strip 220 is stressed and warped, thereby ensuring the connection stability between the structural solder strip 220 and the flexible insulating base material 210.

Figure 10C illustrates another cross-sectional view of the interconnect shown in figure 10A in the direction a-a. As shown in fig. 10C, when a plurality of structural solder strips are pressed between two flexible insulating layers 211 by using a hot pressing process, the conductive layer 212 is embedded in the flexible insulating substrate 210. At this time, after the conductive layer 212 is formed on one flexible insulating layer 211, the structural solder ribbon 220 shown in fig. 7A or 7B may be formed on the surface of the flexible insulating layer 211 on which the conductive layer 212 is formed. On the basis, another flexible insulating layer 211 is laminated on the surface of the flexible insulating layer 211 on which the conductive layer 212 is formed. At this time, each of the structural solder strips 220 has a connecting portion 221 at least partially wrapped between the two flexible insulating layers 211, thereby ensuring that the connecting portion 221 included in each of the structural solder strips 220 is in direct contact with the conductive layer 212.

In an alternative, as shown in fig. 7A and 7B, the connection portion 221 has a hollow-out structure LK for releasing stress, and the other regions of the connection portion 221 except for the hollow-out structure LK are solid structures. At the moment, stress generated by a welding process, a laminating process and outdoor high and low temperature difference can be released by utilizing the hollow structure LK, so that the degree of bending deformation of the back contact battery is reduced, and the welding stability and the long-term use reliability are improved.

The hollow structure LK shown in fig. 7A and 7B may include at least one through hole T. The pattern of each through hole T is a closed pattern. At this time, the closed pattern here means that the outline pattern of the hollow structure LK is closed. In this case, the edge profile of the connecting portion 221 is complete, and the structural solder strip 220 can be ensured to have good strength. The pattern of each through hole is a polygonal pattern, a circular pattern, an oval pattern or a special-shaped pattern. The polygonal pattern may be triangular, rectangular, square, etc. For example, the through-holes may be rectangular in shape and may be 1mm to 10mm in length.

Fig. 11A to 13A illustrate three distribution diagrams of multiple rows of through holes distributed along a first direction in the embodiment of the present invention; fig. 11B to fig. 13B illustrate three distribution diagrams of rows of through holes distributed along the second direction in the embodiment of the present invention. As shown in fig. 11A to 13A and 11B to 13B, the hollow-out structure LK shown in fig. 7A and 7B includes m rows of through holes, where m is an integer greater than or equal to 1. Each row of through holes comprises at least one through hole. The through holes of row 1 and row m are formed in the connection portion 221 in any direction parallel to the connection portion 221. For example: when m is an integer greater than or equal to 2, the 1 st to m-th rows of through holes are distributed along the distribution direction (first direction a) of the first and second welds 221A and 221B. Another example is: when m is an integer greater than or equal to 2, the 1 st to m-th rows of through-holes are distributed along a direction (second direction B) perpendicular to the distribution direction of the first and second welds 221A and 221B.

When the through holes in the 1 st row to the m th row are distributed along the first direction a as shown in fig. 11A to 13A, the through holes T are slit-type through holes or rectangular through holes, and the distribution of the through holes T in two adjacent rows can be appropriately adjusted to ensure that the first welding portion 221A and the second welding portion 221B have a short circuit path under the condition that the strength and the stress relief capability are appropriate.

When the through holes in the 1 st to m th rows are distributed along the second direction B as shown in fig. 11B to 13B, the through holes T are slit-type through holes or rectangular through holes, and if the length direction of the through holes T is distributed from the direction perpendicular to the distribution direction of the first and second soldering portions 221A and 221B, the pitch of the through holes in the two rows may be adjusted so that the current of the first and second soldering portions 221A and 221B is transmitted to the other soldering portion through the connecting portion 221 in a straight line as much as possible, thereby reducing the current loss.

Illustratively, the through holes in two adjacent rows are distributed in a staggered manner. At this time, the m rows of through holes of the connecting part can uniformly release the stress generated by the structural solder strip, thereby further reducing the deformation degree of the back contact battery. The distribution pattern of the rows of through holes can of course also be adjusted to balance the structural strength and stress-relieving capacity of the joint. For example, as shown in fig. 11A and 11B, the connection portion 221 included in the structural solder ribbon 220 has two rows of slit-type through holes which are distributed in a staggered manner, and each row of slit-type through holes includes one slit-type through hole. The two rows of slit-type through holes may be distributed along the first direction a shown in fig. 11A, or may be distributed along the second direction B shown in fig. 11B.

As shown in fig. 11A, when the 2 rows of through holes are distributed in the first direction a, the end of the 1 st row of through holes and the end of the 2 nd row of through holes are staggered so that the current conducted by the first and second welds 221A and 221B can be conducted in the direction of the dotted line shown in fig. 11A at the connection portion.

As shown in fig. 11B, when the 2 rows of through holes are distributed in the second direction B, each row of through holes is a slit-type through hole. The slit-type through-hole has a length direction identical to the first direction a. At this time, the distance between two adjacent rows of slit-type through holes may be adjusted to provide a hardware basis for the first welding portion 221A and the second welding portion 221B to conduct current in the direction of the dotted line shown in fig. 11B.

Illustratively, as shown in fig. 12A and 12B, when m is an integer greater than or equal to 3. The number of through holes in the 1 st row of through holes and the number of through holes in the m th row of through holes are both more than or equal to 2. At this time, along the distribution direction of the 1 st row of through holes to the m th row of through holes, the number of through holes included in each row of through holes is firstly reduced and then increased. Along the distribution direction of the 1 st row through holes to the m th row through holes, if the length of each row of through holes along the row direction is firstly reduced and then increased, along the distribution direction of the 1 st row through holes to the m th row through holes, the structural strength of the connecting part 221 is firstly increased and then reduced, and the stress of the connecting part 221 is firstly gradually reduced and then gradually increased. Based on this, the strength and the stress relief capability of each region of the connection portion 221 can be adjusted by using the distribution manner of the through holes in the connection portion 221, so that the strength and the stress relief capability of the connection portion 221 are coordinated.

As shown in fig. 12A and 12B, when the through holes of the 1 st row and the m th row are formed in the connection portion 221 along the distribution direction of the two soldering portions, if the number of through holes included in each row is first decreased and then increased and the distance between the head and tail ends of each row of through holes and the edge of the connection portion 221 is first decreased and then increased along the distribution direction of the through holes of the 1 st row to the m th row, the current path of the current conducted between the first soldering portion 221A and the second soldering portion 221B is as short as possible in the connection portion 221.

For example, as shown in fig. 12A and 12B, the structural solder ribbon 220 includes a connection portion 221 having 3 rows of slit-type through holes. The 1 st row of through-holes and the 3 rd row of through-holes all include 2 slit formula through-holes, and the 2 nd row of through-holes includes 1 slit formula through-hole. And one slit type through hole included in the 2 nd row of through holes is longer than the slit type through hole included in the 1 st row of through holes, but not more than the end parts of the 1 st row of through holes and the 3 rd row of through holes. At this time, the number of slit type through holes contained in the 1 st row of through holes and the 3 rd row of through holes is large, the number of slit type through holes contained in the 2 nd row of through holes is small at both ends, so that the strain relief capability at both ends of the connecting portion 221 is high, but the strength is weak, the strain relief capability at the middle portion is poor, but the strength is high, therefore, the distribution mode of the m rows of through holes can balance the strain relief capability and the strength of each area of the connecting portion 221, and the structural welding strip has high strain relief capability while ensuring the strength.

As shown in fig. 12A, when the 3 rows of through holes are distributed in the first direction a, the end of the 2 nd row of through holes does not exceed the end of the 1 st and 3 rd rows of through holes, so that the current conducted by the first and second welds 221A and 221B is conducted in the current path of the connection 221 in accordance with the dotted line shown in fig. 12A.

As shown in fig. 12B, when the 3 rows of through holes are distributed along the second direction B, each row of through holes is a slit-type through hole, and the length of the slit-type through holes is distributed along the first direction. At this time, the distance between the slit-type through holes in two adjacent rows may be adjusted so that the current path of the first welding portion 221A and the second welding portion 221B at the connecting portion 221 is conducted according to the dotted line shown in fig. 12B.

For example, as shown in fig. 13A and 13B, when m is an integer greater than or equal to 3, the number of through holes included in the 1 st row of through holes and the m th row of through holes is greater than or equal to 1. Along the distribution direction of the 1 st row of through holes to the m th row of through holes, the number of through holes included in each row of through holes is increased and then decreased.

As shown in fig. 13A and 13B, if the length of each row of through holes along the row direction increases and then decreases along the distribution direction of the 1 st row through holes to the m th row through holes, the structural strength of the connection portion 221 decreases and then increases along the distribution direction of the 1 st row through holes to the m th row through holes, and the stress of the connection portion 221 gradually increases and then gradually decreases. Based on this, the strength and the stress relief capability of each region of the connection portion 221 can be adjusted by using the distribution manner of the through holes in the connection portion 221, so that the strength and the stress relief capability of the connection portion 221 are coordinated.

For example, as shown in fig. 13A and 13B, the structural solder ribbon 220 includes a connection portion 221 having 3 rows of slit-type through holes. The 1 st row of through-holes and the 3 rd row of through-holes all include 1 slit formula through-hole, and the 2 nd row of through-holes includes 2 slit formula through-holes. And one slit type through hole included in the 1 st row of through holes is longer than the slit type through hole included in the 2 nd row of through holes, but the end of the 1 st row of through holes and the end of the 3 rd row of through holes do not exceed the 2 nd row of through holes. At this time, the number of slit type through holes contained in the 1 st row of through holes and the 3 rd row of through holes is smaller, while the number of slit type through holes contained in the 2 nd row of through holes is larger, so that the strength at both ends of the connecting portion 221 is higher, but the stress relief capability is poorer, and the strain relief capability difference at the middle part is higher, but the strength is poorer, therefore, the distribution mode of the m rows of through holes T can balance the strain relief capability and the strength of each area of the connecting portion 221, so that the structural solder strip 220 has higher strain relief capability while ensuring the strength.

As shown in fig. 13A, when the 3 rows of through holes are distributed in the first direction a, the end of the 1 st row of through holes and the 3 rd row of through holes do not exceed the 2 nd row of through holes, so that the current conducted by the first and second welds 221A and 221B can flow in the direction of the dotted line shown in fig. 13A at the connection portion 221.

As shown in fig. 13B, when the 3 rows of through holes are distributed in the second direction B, each row of through holes is a slit-type through hole, and the length direction of the slit-type through holes is distributed along the first direction a. At this time, the distance between the slit type through holes in two adjacent rows may be adjusted so that the current conducted by the first welding part 221A and the second welding part 221B may flow in the direction of the dotted line shown in fig. 13A at the connection part 221.

Fig. 14 is a schematic structural diagram illustrating an apparatus for manufacturing an interconnection member according to an embodiment of the present invention. The manufacturing equipment of the interconnection piece comprises a first feeding mechanism S1, a punch forming mechanism S2, a cutting mechanism S3, a second feeding mechanism S4, a material compounding mechanism S5 and a rolling mechanism S6. The press molding mechanism S2 includes a press head and a molding die. The forming die includes an upper punch and a lower punch. The upper and lower dies have a structural solder ribbon-forming portion corresponding to the structural solder ribbon 220. The structure diagram of the structural solder strip forming part can refer to the structure of the structural solder strip, and specifically includes two solder forming parts and a connection forming part located between the two solder forming parts. The connection forming part is respectively connected with the two welding forming parts, and the connection forming part is provided with a hollow hole structure used for forming a hollow hole structure on the welding strip. The following describes a manufacturing process of the interconnection provided by the embodiment of the present invention with reference to a schematic structural flow diagram of the manufacturing method of the interconnection shown in fig. 15 at each stage.

As shown in fig. 14 and 15, the first feeding mechanism S1 may supply the solder ribbon W shown in fig. 14 to the press forming mechanism. The press forming mechanism S2 includes a press head for controlling the lower die and the upper die to be closed and released, and presses the solder ribbon W to obtain a connection-structure solder ribbon LX shown in fig. 14. The connecting structure strap LX is a one-piece structure formed from a plurality of the previously described structure straps 220. One weld contained by two adjacent structural weld bands 220 is joined. The cutting mechanism S3 is used to cut the welding portion where two adjacent structural welding strips 220 are connected together, so as to form a plurality of independent structural welding strips 220. The second feeding mechanism S4 may provide the flexible insulating substrate 210 to the material compounding mechanism S5. The material combining mechanism S5 may be a hot-press roll-to-roll mechanism, and the flexible insulating substrate 210 may be hot-pressed with the plurality of structural solder strips 220 onto the flexible insulating substrate at 50-120 ℃ for 5-30S (e.g., 100 ℃) to form an interconnection. The winding mechanism winds the interconnection pieces together.

It should be noted that, if the interconnection member is a sandwich structure, the second feeding mechanism S4 may include two feeding rollers, both of which are used for providing the flexible insulating base material 210 to the material combining mechanism S5. The material compounding mechanism S5 can realize compounding of not only a two-layer structure but also a three-layer structure. For example: the plurality of structure welding strips are spaced along the length direction of the flexible insulating base material, and the surface of the flexible insulating base material distribution structure welding strip is formed into the flexible insulating base material in a hot pressing mode, so that the interconnection piece with the sandwich structure is formed.

In the foregoing description of embodiments, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (14)

1. An interconnect for use in interconnecting back contact cells, the interconnect comprising: the flexible welding strip structure comprises a flexible insulating base material and a plurality of structural welding strips arranged on the flexible insulating base material at intervals; each structural welding strip is provided with two welding parts and a connecting part positioned between the two welding parts, and the connecting part is respectively connected with the two welding parts; at least part of the connecting part is positioned on the flexible insulating base material, and the two welding parts extend out of the flexible insulating base material.

2. The interconnection of claim 1, wherein the connecting portion has an openwork structure for stress relief.

3. The interconnection of claim 2, wherein the openwork structure comprises at least one through hole; wherein the content of the first and second substances,

the pattern of each through hole is a closed pattern; and/or the presence of a gas in the gas,

the pattern of each through hole is a polygonal pattern, a circular pattern, an oval pattern or a special-shaped pattern.

4. The interconnection piece of claim 2, wherein the hollowed-out structure comprises m rows of through holes, m being an integer greater than or equal to 1; each row of the through holes comprises at least one through hole, and the 1 st row of the through holes and the m th row of the through holes are formed in the connecting part along any direction parallel to the connecting part.

5. The interconnection of claim 4, wherein two adjacent rows of the through holes are offset; wherein the content of the first and second substances,

the m is an integer larger than or equal to 3, and the number of through holes in the 1 st row of through holes and the number of through holes in the m th row of through holes are both larger than or equal to 2; along the distribution direction from the 1 st row of through holes to the m th row of through holes, the number of through holes included in each row of through holes is firstly reduced and then increased; and/or the presence of a gas in the gas,

the m is an integer larger than or equal to 3, and the number of through holes in the 1 st row of through holes and the number of through holes in the m th row of through holes are both larger than or equal to 1; along the distribution direction of the 1 st row of through holes to the m th row of through holes, the number of through holes included in each row of through holes is increased and then decreased.

6. The interconnection according to any one of claims 1 to 5, wherein the central axes of the two welds are collinear; and/or the presence of a gas in the gas,

every the width of welding part all is less than the maximum width of connecting portion, every the welding part with connecting portion adopt pitch arc transition mode to be connected.

7. The interconnection of any of claims 1 to 5, wherein the flexible insulating substrate is a light-shielding flexible insulating substrate; or the like, or, alternatively,

at least one surface of the flexible insulating substrate is partially or completely provided with a shielding coating; or the like, or, alternatively,

the flexible insulating base material is a single-sided adhesive tape with a release layer or a double-sided adhesive tape with a release layer.

8. The interconnection of any of claims 1 to 5, wherein each of the structural solder strips has a connecting portion exposed away from a surface of the flexible insulating substrate; or the like, or, alternatively,

each structural welding strip is provided with a connecting part which is at least partially wrapped in the flexible insulating base material; or the like, or, alternatively,

each structural solder strip is hot pressed or bonded to the flexible insulating substrate.

9. The interconnection of any of claims 1 to 5, wherein the flexible dielectric substrate has an electrically conductive layer therein, and each of the structural solder strips has a connection portion electrically connected through the electrically conductive layer; wherein the content of the first and second substances,

the conductive layer is a conductive strip or a conductive particle layer formed by mutually contacted metal particles.

10. A solar cell module comprising at least two cells and a plurality of interconnects for interconnecting the cells, each of the interconnects being as claimed in any one of claims 1 to 9; wherein the content of the first and second substances,

the back surface of each battery piece is provided with two polarity welding pads, and each polarity welding pad contained in each polarity welding pad is welded with one welding part contained in the corresponding structural welding strip contained in the corresponding interconnection piece.

11. The solar cell module as claimed in claim 10, wherein a gap is formed between two adjacent cells, the gap accommodates the corresponding interconnection member, the back surface of each cell has pads with two polarities near the edge of the cell, the pads with different polarities of two adjacent cells are near the same gap, and the interconnection members corresponding to the pads with different polarities of two adjacent cells are the same interconnection member.

12. The solar cell assembly of claim 10 further comprising at least one bus bar; each of the bus bars is welded to a weld included in a plurality of structural weld strips of the corresponding interconnection piece.

13. The solar cell module as claimed in claim 12, wherein when the bus bar is located between two adjacent cells, the interconnection pieces corresponding to the pads with different polarities of two adjacent cells are different interconnection pieces, and the interconnection pieces corresponding to the pads with different polarities of two adjacent cells share one bus bar.

14. The solar cell module according to any one of claims 10 to 13, further comprising a visual shielding layer between two adjacent cell sheets, wherein the visual shielding layer is located on the surface of at least one of the interconnection pieces facing the front surface of the cell sheet.

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