Solder strip

Abstract

The utility model relates to the technical field of photovoltaic cells, in particular to a solder strip which is suitable for welding a back contact type photovoltaic cell, the back of the photovoltaic cell is provided with metal electrodes capable of respectively collecting electric energy on the front side of the cell and the back side of the cell, and the solder strip comprises a solder strip body; a plurality of welding holes longitudinally penetrate through the welding strip body; the welding holes are arranged corresponding to metal electrodes of the photovoltaic cells; the insulating layer is at least arranged on a part of the surface of the welding strip body; the insulating layer exposes the welding hole; the plurality of insulating cushion blocks are positioned on one side of the insulating layer; the insulating cushion block is suitable for being in contact with the area, without the metal electrode, of the photovoltaic cell. According to the welding strip provided by the utility model, the positioning is more convenient and accurate through the punching design; and a relatively small gap is formed between one side, facing the photovoltaic cell, of the insulation cushion block and the insulation layer of the welding strip, so that secondary insulation protection of the photovoltaic cell can be realized in lamination.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic cells, in particular to a welding strip. Background Art

[0002] Photovoltaic modules are constructed by connecting multiple photovoltaic cells together using solder ribbons, which are then packaged through processes such as laying and lamination. The solder ribbons create a certain amount of light blocking, reducing the light-receiving surface of the photovoltaic cell and lowering its efficiency. This has led to the development of back-contact photovoltaic cells. Back-contact photovoltaic cells feature metal electrodes on the back of the cell that separately collect power from the front and back of the cell. This allows the cell's surface, especially the front, to fully absorb light, maximizing photoelectric conversion.

[0003] Because back-contact photovoltaic cells have metal electrodes on their surfaces that collect electricity from both the front and back of the cell, special consideration must be given to insulation during welding. Currently, two approaches are to insulate the photovoltaic cell itself with insulating adhesive, which is costly; another is to apply insulating film before welding the photovoltaic cell, which is a difficult process; and another approach is to apply an insulating layer to certain areas of the soldering ribbon itself. However, this method can easily scratch the insulating layer during the ribbon pulling and placement, causing a short circuit in the photovoltaic cell. Utility Model Content

[0004] The technical problem to be solved by the present invention is how to overcome the problems of high cost, great process difficulty and easy short circuit of photovoltaic cells in the insulation treatment of photovoltaic cell welding, thereby providing a welding strip.

[0005] The utility model provides a welding strip, which is suitable for welding back-contact photovoltaic cells. The back of the photovoltaic cell is provided with metal electrodes that can respectively collect the electric energy from the front and back of the cell. The welding strip comprises: a welding strip body; a plurality of welding holes longitudinally passing through the welding strip body; the welding holes are arranged corresponding to the metal electrodes of the photovoltaic cell; an insulating layer provided on at least part of the surface of the welding strip body; the insulating layer exposes the welding holes; and a plurality of insulating pads located on one side of the insulating layer; the insulating pads are suitable for contacting the area of ​​the photovoltaic cell where the metal electrodes are not provided.

[0006] Optionally, the insulating spacer is arranged in an area between adjacent welding holes on the outer peripheral surface of the welding strip body, and a protruding direction of the insulating spacer is consistent with a central axis direction of the welding hole.

[0007] Optionally, the distance between adjacent insulating spacers is at least greater than the diameter of the welding hole.

[0008] Optionally, a welding layer is provided in the welding hole, and the welding layer also extends to the metal electrode on the back side of the photovoltaic cell; the welding layer includes a tin-lead alloy layer or a tin-lead-bismuth alloy layer.

[0009] Optionally, the metal electrodes are in a point shape.

[0010] Optionally, the insulating layer includes a nano-mica insulating layer, a phenol-free polyurethane insulating layer, or a polyurethane insulating layer; the insulating spacer includes an ethylene-vinyl acetate copolymer spacer, an expandable polyethylene spacer, or a polyolefin elastomer spacer.

[0011] Optionally, the cross-sectional shape of the welding strip body is flat, preferably rectangular or elliptical.

[0012] Optionally, the spacing between adjacent insulating spacers is 5 mm to 10 mm; and the aperture of the welding hole is 0.8 mm to 2.0 mm.

[0013] Optionally, the thickness of the insulating layer is 0.1 mm-0.2 mm; the height of the insulating spacer is 0.02 mm-0.06 mm.

[0014] The technical solution of the utility model has the following beneficial effects:

[0015] The utility model provides a welding ribbon for welding back-contact photovoltaic cells. The ribbon body is perforated with welding holes extending longitudinally through the ribbon body. During welding, the ribbon's position can be adjusted at any time to align the welding holes with the photovoltaic cell's metal electrodes, making positioning the ribbon on the photovoltaic cell simpler, more convenient, and more accurate. An insulating layer is provided on at least a portion of the ribbon body's surface, eliminating the need for metal solder in the portion corresponding to the insulating layer. This reduces the use of metal solder and lowers production costs. A plurality of insulating pads are provided on one side of the insulating layer; the insulating pads are suitable for contacting the area of ​​the photovoltaic cell without a metal electrode. In the process of pulling the welding ribbon onto the photovoltaic cell, since only a small area of ​​the insulating pads is in contact with the photovoltaic cell, compared with the pulling and moving of the entire welding ribbon on the photovoltaic cell, the insulating layer can be prevented from being scratched due to the overall friction with the photovoltaic cell, thereby preventing the photovoltaic cell from short-circuiting. Secondly, in the lamination process of the photovoltaic module, since the insulating pads have a certain height, there is a small gap between the side of the insulating pads facing the photovoltaic cell and the insulating layer of the welding ribbon, and the high-temperature melted part of the encapsulation film flows into the gap, thereby realizing secondary insulation protection for the photovoltaic cell and preventing the photovoltaic cell from short-circuiting. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a top view of the welding strip in the embodiment of the present utility model;

[0018] Figure 2 This is a side sectional view of the welding strip in the embodiment of the present utility model;

[0019] Reference numerals:

[0020] 100-welding strip; 110-welding strip body; 120-welding hole; 130-insulating layer; 140-insulating spacer. DETAILED DESCRIPTION

[0021] The following is a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0023] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] Example

[0025] Combined with reference Figure 1 and Figure 2This embodiment provides a welding ribbon 100 suitable for welding back-contact photovoltaic cells, where the back of the photovoltaic cell is provided with metal electrodes that can collect electrical energy from the front and back of the cell respectively, including: a welding ribbon body 110; a plurality of welding holes 120 longitudinally passing through the welding ribbon body 110; the welding holes 120 are arranged corresponding to the metal electrodes of the photovoltaic cell; an insulating layer 130 provided on at least a portion of the surface of the welding ribbon body 110; the insulating layer 130 exposes the welding holes 120; and a plurality of insulating spacers 140 located on one side of the insulating layer 130; the insulating spacers 140 are suitable for contacting areas of the photovoltaic cell where no metal electrodes are provided.

[0026] In this embodiment, the soldering ribbon body 110 is perforated, with welding holes 120 extending longitudinally through the body 110. During the soldering process, the position of the soldering ribbon can be adjusted at any time to align the welding holes 120 with the metal electrodes of the photovoltaic cell. This makes positioning the soldering ribbon on the photovoltaic cell simpler, more convenient, and more accurate. An insulating layer 130 is provided on at least a portion of the surface of the soldering ribbon body 110. The portion corresponding to the insulating layer 130 eliminates the need for metal solder, thereby reducing the use of metal solder and lowering production costs. A plurality of insulating spacers 140 are provided on one side of the insulating layer 130; the insulating spacers 140 are suitable for contacting the area of ​​the photovoltaic cell without a metal electrode. In the process of pulling the welding ribbon onto the photovoltaic cell, since only the insulating spacers 140 have a small area of ​​contact with the photovoltaic cell, compared with the whole welding ribbon being pulled and moved on the photovoltaic cell, the insulating layer 130 can be prevented from being scratched due to the overall friction with the photovoltaic cell, thereby preventing the photovoltaic cell from short-circuiting. Secondly, in the lamination process of the photovoltaic module, since the insulating spacers 140 have a certain height, there is a small gap between the side of the insulating spacers 140 facing the photovoltaic cell and the insulating layer 130 of the welding ribbon, and the high-temperature melted part of the encapsulation film flows into the gap, thereby realizing secondary insulation protection for the photovoltaic cell and preventing the photovoltaic cell from short-circuiting.

[0027] In one embodiment, the insulating spacers 140 are disposed in the area between adjacent welding holes 120 on the outer circumferential surface of the welding ribbon body 110, and the protruding direction of the insulating spacers 140 is aligned with the central axis of the welding holes. Since the welding holes 120 are arranged corresponding to the metal electrodes of the photovoltaic cell, at least one opening of the welding hole 120 in the welding ribbon body 110 faces one side of the photovoltaic cell, and the protruding direction of the insulating spacers 140 is aligned with the central axis of the welding hole 120, during the welding ribbon pulling process, the insulating spacers 140 contact the photovoltaic cell, preventing scratches on the insulating layer 130 and causing a short circuit in the photovoltaic cell.

[0028] In one embodiment, the distance between adjacent insulating spacers 140 is at least greater than the diameter of the welding hole 120 .

[0029] In one embodiment, the spacing between adjacent insulating blocks 140 is 5 mm to 10 mm, for example, 5 mm, 8 mm, or 10 mm. If the spacing between adjacent insulating blocks is too small, the clamping distance of the ribbon pulling claws may increase, which may cause the ribbon to fall. At the same time, due to the small spacing, the number of blocks increases, which increases the cost. If the spacing between adjacent insulating blocks is too large, the chance of the insulation layer being scratched increases.

[0030] In one embodiment, the diameter of the welding hole 120 is 0.8 mm to 2.0 mm, for example, 0.8 mm, 1.0 mm, or 2.0 mm. If the diameter of the welding hole is too small, the subsequent welding layer will have less contact with the metal electrode, resulting in low welding reliability. If the diameter of the welding hole is too large, the size of the welding layer will be too large, wasting welding paint.

[0031] In one embodiment, the insulating spacers 140 are arranged at equal intervals along the length of the soldering ribbon. The insulating spacers 140 are evenly distributed on one side of the insulating layer of the soldering ribbon, which can improve the stability of the soldering ribbon during the pulling process.

[0032] In other embodiments, the insulating spacers may be arranged at unequal intervals along the length direction of the welding strip.

[0033] In one embodiment, the height of the insulating spacer 140 is 0.02 mm to 0.06 mm, for example, 0.02 mm, 0.04 mm, or 0.06 mm. If the insulating spacer is too high, the distance between the soldering ribbon and the photovoltaic cell will be too large, which may easily cause the photovoltaic cell to break. If the insulating spacer is too low, the effect of preventing the insulating layer from being scratched will be poor.

[0034] In one embodiment, the thickness of the insulating layer 130 is 0.1 mm to 0.2 mm, for example, 0.0 mm, 0.15 mm, or 0.2 mm. If the thickness of the insulating layer is too large, the process cost is high; if the thickness of the insulating layer is too small, the probability of short circuit of the photovoltaic cell increases.

[0035] In one embodiment, the insulating layer 130 includes a nano-mica insulating layer, a phenol-free polyurethane insulating layer, or a polyurethane insulating layer; the insulating spacer 140 includes an ethylene-vinyl acetate copolymer spacer, an expandable polyethylene spacer, or a polyolefin elastomer spacer; and the welding layer includes a tin-lead alloy layer or a tin-lead-bismuth alloy layer.

[0036] In one embodiment, the cross-section of the soldering ribbon body 110 is flat, preferably rectangular or oval. When the shape of the soldering ribbon body 110 is rectangular, the width of the soldering ribbon body 110 is 0.3 mm to 0.7 mm.

[0037] In one embodiment, a welding layer is provided in the welding hole 120 , and the welding layer also extends to the metal electrode on the back side of the photovoltaic cell.

[0038] Specifically, the photovoltaic cell is placed on the welding platform with the front side facing down and the back side facing up, and the welding ribbon is pulled onto the photovoltaic cell. The welding hole 120 is arranged corresponding to the metal electrode on the back of the photovoltaic cell, and the insulating pad 140 is in contact with the area on the back of the photovoltaic cell where no metal electrode is set. The welding coating (such as solder paste) is filled into the welding hole 120 through the welding coating equipment to form a welding layer. The welding layer also extends to the metal electrode on the back of the photovoltaic cell, which is used to realize the connection between the welding ribbon and the metal electrode on the back of the photovoltaic cell.

[0039] In this embodiment, the metal electrodes are in the form of dots. Those skilled in the art also refer to these as pad dots. It is understood that the metal electrodes (including both the positive and negative electrodes) in a back-contact photovoltaic cell are located on the back of the photovoltaic cell. Therefore, during welding, the welding layer connects to the metal electrodes on the back of the photovoltaic cell, not the front.

[0040] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A welding strip suitable for welding back-contact photovoltaic cells, the back of which is provided with metal electrodes capable of collecting the front power of the cell and the back power of the cell respectively, characterized in that: include: Welding strip body; The welding strip body is longitudinally penetrated by a plurality of welding holes; The welding holes are arranged corresponding to the metal electrodes of the photovoltaic cells; An insulating layer is provided at least on a portion of the surface of the welding strip body; the insulating layer exposes the welding hole; A plurality of insulating pads are located on one side of the insulating layer; the insulating pads are suitable for contacting with the area of ​​the photovoltaic cell where no metal electrodes are arranged.

2. The welding strip according to claim 1, characterized in that: The insulating spacer is arranged in a region between adjacent welding holes on the outer peripheral surface of the welding strip body, and a protruding direction of the insulating spacer is consistent with a central axis direction of the welding hole.

3. The welding strip according to claim 2, characterized in that: The distance between adjacent insulating spacers is at least greater than the diameter of the welding hole.

4. The welding strip according to claim 1, characterized in that: The insulating spacers are arranged at equal intervals along the length direction of the welding strip.

5. The welding strip according to claim 1, characterized in that: A welding layer is provided in the welding hole, and the welding layer also extends to the metal electrode on the back side of the photovoltaic cell; The soldering layer includes a tin-lead alloy layer or a tin-lead-bismuth alloy layer.

6. The welding strip according to claim 5, characterized in that: The metal electrodes are in point shape.

7. The welding strip according to any one of claims 1 to 6, characterized in that: The insulating layer comprises a nano-mica insulating layer, a phenol-free polyurethane insulating layer, or a polyurethane insulating layer; The insulating spacer includes an ethylene-vinyl acetate copolymer spacer, an expandable polyethylene spacer or a polyolefin elastomer spacer.

8. The welding strip according to any one of claims 1 to 6, characterized in that: The cross-sectional shape of the welding strip body is flat.

9. The welding strip according to claim 8, The cross-sectional shape of the welding strip body is rectangular or elliptical.

10. The welding strip according to any one of claims 1 to 6, characterized in that: The spacing between adjacent insulating pads is 5mm-10mm; the diameter of the welding hole is 0.8mm-2.0mm.

11. The welding strip according to any one of claims 1 to 6, characterized in that: The thickness of the insulating layer is 0.1 mm-0.2 mm; the height of the insulating spacer is 0.02 mm-0.06 mm.

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