Solar cell string and solar cell module

Abstract

The utility model relates to the technical field of solar cells, and discloses a solar cell string and a solar cell module, the solar cell string comprises a plurality of cells, the cells are provided with grid lines, and the grid lines are provided with pad points; the plurality of welding strips are used for connecting the battery pieces and enabling the battery pieces to be arranged in sequence; each welding strip is connected with the pad point, each welding strip is connected with the battery piece and / or the grid line through a pre-fixing point, and the pre-fixing point is a non-UV glue point. According to the solar cell string, each welding strip is connected with the cell piece and / or the grid line through the pre-fixing points, a good pre-fixing effect is achieved on each welding strip, arrangement of UV glue and curing operation of the UV glue are avoided, working procedures are reduced, meanwhile, cost is reduced, and the solar cell string is good in reliability and stable in performance.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of solar cell, especially a solar cell string and solar cell module. BACKGROUND

[0002] Solar cell is usually connected and packaged by a plurality of solar cell strings, and the solar cell string is usually connected by a plurality of solar cell pieces by welding band. In the prior art, the process flow of manufacturing the solar cell string mainly includes: arranging UV glue points 150 on the cell piece 110 to form a plurality of glue points; carrying the welding band 140 and placing the welding band 140 on the grid line 120 according to the predetermined interval; and welding the welding band 140 to the grid line 120 on the surface of the cell piece 110 after pressing the welding band 140 under the welding band clamp and curing the UV glue points 150. The structure of the formed solar cell string is shown in the figure. Figure 1 The main principle is to fix the welding band by using adhesive, the fixing effect is good, the adhesive layer is mostly UV glue layer, but this process needs UV glue point glue and UV glue curing, the process is complex, and the cost is high, so it is difficult to apply the welding band fixing mode to industrialization. INVENTION CONTENTS

[0003] The utility model solves the technical problem that the UV glue setting and UV glue curing operation are avoided, the process is reduced, the cost is reduced, the reliability of the solar cell string is good, and the performance is stable.

[0004] In order to solve the above technical problems, the utility model provides a solar cell string, which comprises:

[0005] A plurality of cell pieces, the cell piece is provided with a grid line, and the grid line is provided with a pad point;

[0006] A plurality of welding bands for connecting the cell pieces and arranging them in sequence;

[0007] Each welding band is connected with the pad point, and each welding band is connected with the cell piece and / or the grid line through a pre-fixing point, and the pre-fixing point is a non-UV glue point.

[0008] As an improvement of the above scheme, the pre-fixing point is a welding point formed after spot pressing or spot welding.

[0009] As an improvement of the above scheme, the cell piece is provided with a fine grid, the fine grid extends along a first direction, the welding band extends along a second direction, and the first direction is different from the second direction.

[0010] The pad points are arranged on the fine grid, each of the solder strips is connected with the pad points, and each of the solder strips is connected with the battery piece and / or the fine grid through the pre-fixing points.

[0011] As an improvement of the above scheme, the battery piece is provided with a fine grid and a main grid, the main grid and the solder strip extend along a second direction, and the fine grid extends along a first direction, each of the main grids intersects with a plurality of fine grids;

[0012] The pad points are arranged on the main grid, each of the solder strips is connected with the pad points, and each of the solder strips is connected with the battery piece, the main grid and / or the fine grid through the pre-fixing points.

[0013] As an improvement of the above scheme, along the extension direction of the solder strip, the pad points arranged at both ends of the solder strip are edge pad points, and the pre-fixing points are located between the edge of the battery piece along the second direction and the edge pad points.

[0014] As an improvement of the above scheme, the pre-fixing points are located between adjacent two pad points, and the number of pre-fixing points arranged between adjacent two pad points is 1-3.

[0015] As an improvement of the above scheme, the shape of the pre-fixing point is one or more of a cube, a prism, a cuboid, a cylinder, a sphere and a cone.

[0016] As an improvement of the above scheme, the area of the pre-fixing point is 1mm 2 -10mm, and the height is 5-50μm.

[0017] As an improvement of the above scheme, the distance between adjacent pre-fixing points is 1-9mm.

[0018] As an improvement of the above scheme, the number of pre-fixing points on each solder strip is 4-15;

[0019] The distance between the pre-fixing point and the adjacent pad point is 5%-20% of the length of each solder strip.

[0020] As an improvement of the above scheme, the pre-fixing points are arranged at equal intervals on each solder strip.

[0021] As an improvement of the above scheme, the pre-fixing points are arranged at unequal intervals on each solder strip.

[0022] As an improvement of the above scheme, the width of the main grid is 0.3-2mm, and the width of the solder strip is 0.3-3mm.

[0023] As an improvement of the above scheme, 4-15 pad points are arranged on the grid line.

[0024] As an improvement of the above scheme, each of the solder strips is connected to the pad points through a metal layer.

[0025] As an improvement of the above scheme, the metal layer is one of a tin paste layer, a silver paste layer, a copper paste layer and a silver-copper paste layer.

[0026] As an improvement of the above scheme, the shape of the solder strip is one of a circle, an ellipse and a polygon.

[0027] The solder strip is one of a tin-plated copper solder strip, a bismuth-plated copper solder strip, a silver-plated copper solder strip, an indium-plated copper solder strip and a tin-lead alloy-plated copper solder strip.

[0028] The utility model discloses a solar cell module, which comprises the solar cell string.

[0029] The utility model discloses a solar cell string, which has the following beneficial effects:

[0030] In the utility model, each of the solder strips is connected to the battery piece and / or the grid line through a pre-fixing point, and each of the solder strips is connected to the battery piece and / or the grid line through the pre-fixing point, which plays a good pre-fixing role on each of the solder strips, avoids the setting of UV glue and the curing operation of UV glue, reduces the process, and reduces the cost. Subsequently, each of the solder strips is connected to the pad points, which is used for connecting a plurality of the battery pieces in series or parallel, improves the reliability and performance stability of the solar cell string, and is conducive to collecting and transmitting the current generated by the battery pieces to the junction box of the module, and then connecting to the external circuit. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 : a partial structure diagram of a solar cell string in the prior art;

[0032] Figure 2 : a partial structure diagram of a solar cell string in the utility model;

[0033] Figure 3 : a connection diagram of a single battery piece (with a main grid) pre-fixing point in the utility model;

[0034] Figure 4 : a connection diagram of a single battery piece (without a main grid) pre-fixing point in the utility model.

[0035] Reference signs:

[0036] 100 - solar cell string; 110 - battery piece; 120 - grid line; 121 - fine grid; 122 - main grid; 130 - pad point; 140 - solder strip; 150 - UV glue point; 160 - pre-fixing point. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the utility model more clear, the utility model will be described in further detail by specific embodiments.

[0038] In order to make the purpose, technical scheme and advantages of the utility model more clear, the utility model will be described in further detail by specific embodiments.

[0039] In the description of the present application, it should be understood that the terms "upper", "lower", "back", "front" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0040] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "above", "over" and "on" of the first feature to the second feature include that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "below", "under" and "under" of the first feature to the second feature include that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0041] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeatedly refer to numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides various specific examples of processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0042] Reference to "an embodiment" or "the embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment or embodiments can be included in at least one embodiment. The appearances of the phrase "in one embodiment" or "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily all directed to the same embodiments. It is expressly understood that the embodiments described herein are merely examples from a multitude of possible embodiments.

[0043] To solve the above problems, the utility model provides a kind of solar cell string 100, please refer to Figure 2 Including:

[0044] A plurality of cell pieces 110, the cell piece 110 is provided with grid line 120, pad point 130 is equipped on the grid line 120;

[0045] A plurality of solder strips 140 for connecting the cell piece 110 and making it arrange in turn;

[0046] Each solder strip 140 is connected with pad point 130, and each solder strip 140 is connected with cell piece 110 and / or grid line 120 by pre-fixing point 160, and the pre-fixing point is non-UV glue point.

[0047] In the utility model, each solder strip 140 is connected with cell piece 110 and / or grid line 120 by pre-fixing point 160, first, each solder strip 140 is connected with cell piece 110 and / or grid line 120 by pre-fixing point 160, and it plays a good pre-fixing effect to each solder strip 140, avoids the setting of UV glue point 150 and the curing operation of UV glue point 150, reduces process, and then reduces the use of UV glue, reduces cost. Subsequently, each solder strip 140 is connected with pad point 130, for connecting a plurality of cell pieces 110 in series or parallel, improve the reliability of solar cell string 100, and it is favorable to collect and transmit the current generated by cell piece 110 to the junction box of assembly, and then connected to external circuit.

[0048] It can be understood that the silicon wafer is the core part of the cell sheet 110, and the surface thereof is very sensitive and easy to be damaged. Direct welding on the surface of the cell sheet 110 can cause thermal damage or mechanical damage, affect the performance and service life of the cell, and the solder strip 140 directly welded on the cell sheet 110 can increase the risk of breaking the cell sheet 110. Therefore, each solder strip 140 is preferably connected to the grid line 120 through a pre-fixing point 160, and each solder strip 140 is preferably connected to the cell sheet 110 and the grid line 120 through a pre-fixing point 160, which can increase the shielding of incident light and reduce the photoelectric conversion efficiency of the cell sheet 110. Alternatively, the pre-fixing point 160 is a welding point formed after spot pressing or spot welding, and the pre-fixing point formed by spot pressing or spot welding has no effect on the structure and performance of the cell sheet 110. For example, the spot pressing can be a method of spot pressing with a soldering iron, and the spot welding can be a method of spot welding with a laser. The process of the spot pressing and the spot welding is not limited in the present application. In some embodiments, the solder strip 140 can be placed on the cell sheet 110 by using a solder strip clamping jaw, and then a soldering iron or a laser on the solder strip clamping jaw can be used to weld a specific area, thereby achieving the effect of fixing the solder strip 140. The pre-fixing point 160 is one or more of a tin paste point, a silver paste point, a copper paste point, and a silver-copper point.

[0049] Alternatively, the cell sheet 110 is a cell sheet 110 without a main grid 122, as shown in Figure 3 , the cell sheet 110 is provided with a fine grid 121, the fine grid 121 extends along a first direction, the solder strip 140 extends along a second direction, and the first direction is different from the second direction; the pad point 130 is arranged on the fine grid 121, each solder strip 140 is connected to the pad point 130, and each solder strip 140 is connected to the cell sheet 110 and / or the fine grid 121 through a pre-fixing point 160. At this time, the pre-fixing point 160 is arranged on the surface of the cell sheet 110 or the fine grid 121, and the current is transmitted from the fine grid 121 to the solder strip 140. By redistributing the transmission path of the current, the carrier transmission distance can be shortened, and the transmission loss can be reduced.

[0050] Alternatively, the cell sheet 110 is a cell sheet 110 with a main grid 122, as shown in Figure 4The battery piece 110 is provided with a fine grid 121 and a main grid 122. The main grid 122 and the fine grid 121 are arranged on the surface of the battery piece 110 in a cross manner. The fine grid 121 is used to collect the current of the polar region. The fine grid 121 and the main grid 122 are arranged in an alternating manner. The main grid 122 and the solder strip 140 extend along a second direction. The fine grid 121 extends along a first direction. Each main grid 122 intersects with a plurality of fine grids 121. The pad point 130 is arranged on the main grid 122. Each solder strip 140 is connected with the pad point 130. Each solder strip 140 is connected with the battery piece 110, the main grid 122 and / or the fine grid 121 through a pre-fixing point 160. At this time, the pre-fixing point 160 is arranged on the surface of the battery piece 110, on the main grid 122, on the fine grid 121 or at the intersection of the main grid 122 and the fine grid 121. Therefore, when the current is collected from the fine grid 121 to the main grid 122 and then transmitted to the solder strip 140, the transmission path of the current is redistributed, the transmission distance of the carrier is shortened, and the transmission loss is reduced.

[0051] Further, along the extension direction of the solder strip 140, the pad points 130 arranged at the two ends of the solder strip 140 are edge pad points. The pre-fixing point 160 is located between the edge of the battery piece 110 along the second direction and the edge pad point. It should be noted that the two ends of the solder strip 140 refer to the regions close to the two end points of the solder strip 140, rather than the two end points of the solder strip 140. Alternatively, the pre-fixing point 160 is located between the adjacent two pad points 130. The number of pre-fixing points 160 arranged between the adjacent two pad points 130 is 1-3. The pre-fixing of the solder strip 140 can be achieved, and the arrangement of the pad points 130 will not be hindered. In some preferred embodiments, the pre-fixing point 160 includes a plurality of points arranged between the edge of the battery piece 110 along the second direction and the edge pad point and between the adjacent two pad points 130. The positioning effect of the solder strip 140 is good, and the solder strip 140 can be welded on the battery piece 110 according to the designed path.

[0052] It can be understood that the width of the solder strip 140 is usually matched with the width of the main grid 122 or the width of the solder strip 140 is usually slightly larger than the width of the main grid 122 to ensure good welding contact and electrical connection. In some preferred embodiments, the width of the main grid 122 is 0.3-2 mm, and the width of the solder strip 140 is 0.3-3 mm.

[0053] It should be noted that the first direction and the second direction intersect. Preferably, the first direction and the second direction are perpendicular to each other; more preferably, the first direction is the transverse direction of the battery piece 110, and the second direction is the longitudinal direction of the battery piece 110, and the two are perpendicular to each other. Of course, in other embodiments, the first direction and the second direction can also be other directions, and the present application does not make specific limitations thereto.

[0054] Preferably, the shape of the pre-fixing point 160 is one or more of a cube, a prism, a cuboid, a cylinder, a sphere, and a cone, which can provide sufficient welding surface for the welding strip 140, and in turn be pre-fixed on the battery piece 110 and / or the grid line 120. The area of the pre-fixing point 160 is 1mm 2 ~10mm, which ensures that the welding strip 140 achieves good pre-fixing on the battery piece 110 and / or the grid line 120. It can be understood that the area of the pre-fixing point 160 refers to the area of the shape of the pre-fixing point 160 in contact with the welding strip 140. For example, when the shape of the pre-fixing point 160 is a square, the area of the pre-fixing point 160 is 1mm 2 ~10mm, specifically, the area of the square in contact with the welding strip 140 is 1mm 2 ~10mm; when the shape of the pre-fixing point 160 is a prism, specifically, the area of the quadrilateral in contact with the welding strip 140 is 1mm 2 ~10mm. The height of the pre-fixing point 160 is 5~50μm, for example, 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm. If the height of the pre-fixing point 160 is too high, it will increase the amount of solder pads, increase the cost, and also increase the shielding of incident light, reduce the photoelectric conversion efficiency.

[0055] The number of pre-fixing points 160 and the power loss of the grid line 120 have a certain relationship. The pre-fixing point 160 is a key component for connecting the positive and negative poles inside the battery, and its number will directly affect the transmission path and uniformity of the current inside the battery. Through the cooperation of the pre-fixing point 160 and the pad point 130, the welding strip 140 is fixed on the battery piece 110, achieving the effect of uniform current transmission. Please refer to Figure 3The interval L1 between the pre-fixing points 160 and the adjacent pad points 130 is 5-20% of the length L2 of each solder strip 140, which realizes the initial fixation of the solder strip 140, avoids the stress deviation during the pad welding fixation, and also does not increase the light shielding area due to excessive fixation points. For example, the interval L1 between the pre-fixing points 160 and the adjacent pad points 130 is 5%, 10%, 15%, or 20% of the length L2 of each solder strip 140, but is not limited thereto. Optionally, the grid line 120 is provided with 4-15 pad points 130, which has a good fixation effect on the solder strip 140, reduces the risk of the solar cell string 100 breaking, shortens the carrier transmission distance, reduces the series resistance of the cell sheet 110, reduces the transmission loss of the carrier, and improves the output power of the current.

[0056] In some preferred embodiments, the number of pre-fixing points 160 on each solder strip 140 is 4-15. When the number of pre-fixing points 160 is too small, the current transmission may be unbalanced, resulting in excessively high current density in some areas and insufficient current density in other areas. When the number of pre-fixing points 160 is too large, the current collection effect is reduced, the internal resistance is increased due to the occupation of too much space, the cost is too high, and warping and even cracking are easily caused. Alternatively, the interval L3 between the adjacent pre-fixing points 160 on each solder strip 140 is 1-9 mm. Too small interval L3 may cause heat overlap between the pre-fixing points 160, and too large interval L3 may lengthen the current transmission path, resulting in an increase in power loss. It can be understood that the pre-fixing points 160 are arranged at equal intervals on each solder strip 140, or the pre-fixing points 160 are arranged at unequal intervals on each solder strip 140, and the distribution of the pre-fixing points 160 is not limited in the application and can be flexibly adjusted according to the implementation.

[0057] It should be noted that the pad point 130 is a metal electrode designed at a specific position on the surface of the solar cell, which plays an important role in connecting the electrical connection between the cell sheet and the circuit board. These points are usually used to connect electrodes and wires, and connect other photovoltaic components, such as connecting multiple cell sheets in series to form a battery pack, or connecting multiple battery packs in parallel to form a photovoltaic cell array. In addition, the pad point can withstand high voltage in the solar photovoltaic system to ensure stable operation of the system. Therefore, those skilled in the art can know that the place where the width of the grid line suddenly widens can be identified as a pad point.

[0058] Preferably, each of the solder strips 140 is connected to the pad points 130 through a metal layer (not labeled in the figure), which can reduce the current transmission loss on the gate lines 120. Optionally, the metal layer is one of a tin paste layer, a silver paste layer, a copper paste layer, and a silver-copper paste layer, and the composition of the metal layer is not limited in the application and can be flexibly adjusted according to actual conditions.

[0059] It can be understood that the solder strip 140 has one of a circular shape, an elliptical shape, and a polygonal shape, and the solder strip 140 is one of a tin-plated copper solder strip, a bismuth-plated copper solder strip, a silver-plated copper solder strip, an indium-plated copper solder strip, and a tin-lead alloy-plated copper solder strip. The shape of the solder strip 140 and the composition of the solder strip 140 are not limited in the application and can be flexibly adjusted according to actual conditions.

[0060] Correspondingly, the utility model also provides a solar cell module which comprises the solar cell string 100.

[0061] It can be understood that the solar cell module can further comprise a metal frame, a front plate, a back plate, and a film.

[0062] The back plate can protect and support the cell string and has reliable insulation, water resistance, and aging resistance. The back plate can be selected from multiple options, and is usually tempered glass, organic glass, aluminum alloy TPT composite film, KPC, CPC, etc. The specific setting can be made according to specific conditions, and is not limited in the application.

[0063] The front plate, such as photovoltaic glass, can cover the film on the light-receiving surface of the solar cell. The front plate can be super white glass, which has high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, the light transmittance of super white glass can be more than 92%, which can protect the cell sheet 110 without affecting the efficiency of the cell sheet 110 as much as possible. Meanwhile, the film can bond the front plate and the solar cell together. The film can seal, insulate, and waterproof and moisture-proof the solar cell. The film has multiple options, including but not limited to one or more of the following: EPE film layer, EVA film layer, POE film layer, EVA-POE film layer. The back plate, the solar cell, the film, and the front plate can be arranged on the metal frame, which serves as the main external support structure of the entire solar cell module and can stably support and install the solar cell module. For example, the solar cell module can be installed at a desired installation position through the metal frame.

[0064] The above disclosure is only a preferred embodiment of the utility model, and of course cannot limit the scope of the utility model. Therefore, equivalent changes made according to the claims of the utility model still fall within the scope of the utility model.

Claims

1. A solar cell string, characterized by, include: A plurality of battery cells, wherein grid lines are provided on the battery cells and pad points are provided on the grid lines; Several solder strips for connecting the battery cells and arranging them in sequence; Each of the solder strips is connected to the pad point, and each of the solder strips is connected to the cell and / or grid line via a pre-fixed point, which is a non-UV adhesive point.

2. The solar cell string of claim 1, wherein, The pre-fixed point is a welding point formed after hot stamping or spot welding.

3. The solar cell string of claim 1, wherein, The battery cell is provided with a fine grid, the fine grid extends along a first direction, and the solder strip extends along a second direction, the first direction being different from the second direction; The pad point is located on the grid, each of the solder strips is connected to the pad point, and each of the solder strips is connected to the cell and / or grid through a pre-fixed point.

4. The solar cell string of claim 1, wherein, The battery cell is provided with fine grids and main grids, the main grids and solder strips extend along a second direction, the fine grids extend along a first direction, and each main grid intersects with multiple fine grids; The pad point is located on the main grid, and each of the solder strips is connected to the pad point. Furthermore, each of the solder strips is connected to the battery cell, the main grid, and / or the fine grid through a pre-fixed point.

5. Solar cell string according to any of claims 1 to 4, characterized in that Along the extension direction of the solder strip, the pad points at both ends of the solder strip are edge pad points, and the pre-fixing point is located between the edge of the battery cell along the second direction and the edge pad point.

6. Solar cell string according to any of claims 1 to 4, characterized in that The pre-fixed point is located between two adjacent pad points, and the number of pre-fixed points set between two adjacent pad points is 1 to 3.

7. The solar cell string of claim 1, wherein, The shape of the pre-fixed point is one or more of the following: cube, frustum, cuboid, cylinder, sphere, and cone.

8. The solar cell string of any one of claims 1-4, wherein the solar cell string is a bifacial solar cell string. The area of the pre-fixing point is 1mm 2 ~ 10mm, and the height is 5~50μm.

9. The solar cell string of any one of claims 1-4, wherein the solar cell string is a bifacial solar cell string. The distance between adjacent pre-fixed points is 1 to 9 mm.

10. The solar cell string of claim 9, wherein the solar cell string is a bifacial solar cell string. The number of pre-fixed points on each of the aforementioned welding strips is 4 to 15; The distance between the pre-fixed point and the adjacent pad point is 5% to 20% of the length of each welding strip.

11. The solar cell string of claim 10, wherein the solar cell string is a bifacial solar cell string. The pre-fixed points are set at equal intervals on each welding strip.

12. The solar cell string of claim 10, wherein the solar cell string is a bifacial solar cell string. The pre-fixed points are set at unequal intervals on each welding strip.

13. The solar cell string of claim 4, wherein the solar cell string is a bifacial solar cell string. The width of the main grid is 0.3 to 2 mm; the width of the solder strip is 0.3 to 3 mm.

14. The solar cell string of claim 1, wherein, The grid line has 4 to 15 pad points.

15. The solar cell string of any one of claims 1-4, wherein the solar cell string is a bifacial solar cell string. Each of the solder strips is connected to the pad point via a metal layer.

16. The solar cell string of claim 15, wherein, The metal layer is one of the following: solder paste layer, silver paste layer, copper paste layer, or silver-copper paste layer.

17. The solar cell string of claim 1, wherein, The shape of the welding strip is one of the following: circular, elliptical, or polygonal. The solder strip is one of the following: tin-plated copper solder strip, bismuth-plated copper solder strip, silver-plated copper solder strip, indium-plated copper solder strip, and tin-lead alloy copper solder strip.

18. A solar cell module characterized by comprising: Includes the solar cell string as described in any one of claims 1 to 17.

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