IBC photovoltaic cell packaging structure and IBC photovoltaic cell

Abstract

The utility model relates to the technical field of photovoltaic cells, and discloses an IBC photovoltaic cell packaging structure and an IBC photovoltaic cell. The IBC photovoltaic cell packaging structure provided by the utility model comprises a back panel which comprises a transparent substrate and a transparent conductive layer, the transparent conductive layer is arranged on the transparent substrate, and the transparent conductive layer forms a circuit structure; the first surface of the back transparent insulating layer is connected to the first surface of the back panel; the first surfaces of the plurality of battery pieces are connected to the second surface of the back transparent insulating layer; wherein the first surface of the back panel is provided with conductive parts corresponding to the grid lines of the battery pieces, the back transparent insulating layer is provided with through holes corresponding to the conductive parts, the conductive parts penetrate through the through holes, one ends of the conductive parts are electrically connected with the circuit structure, and the other ends of the conductive parts are electrically connected with the connecting ports of the corresponding grid lines. According to the technical scheme provided by the utility model, the problem that the silicon wafer is easy to bend when the IBC photovoltaic cell is welded can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic cells, in particular to an IBC photovoltaic cell packaging structure and an IBC photovoltaic cell. Background Art

[0002] IBC photovoltaic cells (all-back electrode contact crystalline silicon photovoltaic cells) are photovoltaic cells with both positive and negative electrodes set on the back of the cell. There is no grid line blocking the front, so the front can receive all the sunlight. However, since the electrodes of IBC photovoltaic cells are all set on the back, the welding process of IBC photovoltaic cells requires special interconnection welding ribbons for connection to collect and output current.

[0003] In the prior art, the welding ribbon usually needs to be customized according to the back structure of the photovoltaic cell. When the IBC photovoltaic cells are connected in series, the complete welding ribbon is usually cut and cut to connect the positive and negative electrodes of two adjacent cells. Since the welding of IBC photovoltaic cells changes from double-sided welding to single-sided welding, the silicon wafer is easily bent by heat during single-sided welding, which increases the difficulty of the process.

[0004] Therefore, how to solve the problem in the prior art that the solar cells are easily bent due to heat when the IBC photovoltaic cells are welded has become an important technical problem to be solved by those skilled in the art. Utility Model Content

[0005] In view of this, the utility model provides an IBC photovoltaic cell packaging structure and an IBC photovoltaic cell to solve the problem that silicon wafers are easily bent due to heat when the IBC photovoltaic cells are welded.

[0006] In a first aspect, the utility model provides an IBC photovoltaic cell packaging structure, comprising:

[0007] A back panel, comprising a transparent substrate and a transparent conductive layer, wherein the transparent conductive layer is disposed on the transparent substrate and forms a circuit structure;

[0008] A back transparent insulating layer, a first surface of which is connected to the first surface of the back panel;

[0009] A plurality of battery cells, each of which has a gate line on its first surface, and the first surfaces of the plurality of battery cells are connected to the second surface of the back transparent insulating layer; wherein,

[0010] A conductive portion corresponding to the grid line of each of the cells is provided on the first surface of the back panel, and a through hole corresponding to the conductive portion is provided on the back transparent insulating layer, and the conductive portion passes through the through hole, and one end of the conductive portion is electrically connected to the circuit structure, and the other end is electrically connected to the connection port of the corresponding grid line, so that the multiple cells output current through the circuit structure. In addition, the transparent conductive layer can be formed by a transparent conductive material, and the transparent conductive layer can be formed on a transparent substrate by a printing or plating process. It should be noted that the transparent conductive layer forms a circuit structure, which can not only realize the current output of multiple cells, but also because of the use of transparent materials, it will not affect the light transmittance of the back panel, and the light is absorbed by the cell through the transparent substrate, the transparent conductive layer and the back transparent insulating layer, thereby improving the double-sidedness of the photovoltaic cell assembly.

[0011] Beneficial effects:

[0012] The IBC photovoltaic cell packaging structure provided by the utility model includes a back panel, a back transparent insulating layer and a plurality of cells, wherein the grid lines of the cells are arranged on the back of the cells, that is, the backlight surface. A circuit structure is arranged on the back panel, and the circuit structure is provided with a conductive part, and the conductive part passes through the through hole of the back transparent insulating layer to connect with the connection port of the grid line, and then the current output of each cell is realized through the circuit structure. Since the distance between the conductive parts is relatively close, the back transparent insulating layer can be used to separate the conductive parts, avoiding the problem of short circuit caused by mutual contact of the conductive parts. The technical solution provided by the utility model does not need to use welding strips for welding, avoiding the problem of the cell being easily bent by heat.

[0013] In an optional implementation, the conductive part is made of conductive glue, and the conductive glue is disposed on the first surface of the back panel by printing.

[0014] Beneficial effects:

[0015] The conductive glue is set on the first surface of the back panel by printing, which improves the layout accuracy and efficiency of the conductive glue. When the conductive glue is electrically connected to the battery cell, it is only necessary to contact the conductive glue with the connection port of the grid line of the battery cell and heat the conductive glue. The conductive glue can be electrically connected to the connection ports of the positive grid line and the negative grid line by hot melting, which effectively improves the connection efficiency.

[0016] In an optional implementation, the conductive adhesive is connected to the connection port of the gate line through a hot melt process.

[0017] Beneficial effect: Through the hot-melt process, the conductive glue can be quickly connected to the connection port of the gate line. During the processing, after each conductive glue is aligned with the corresponding connection port of the gate line, the conductive glue can be melted by heating the entire assembly, and pressure is applied to press the conductive glue and the connection port of the gate line, so that the conductive glue in the hot-melt state is bonded to the connection port. Compared with the prior art of welding the welding strip and the battery cell one by one, the technical solution provided in this embodiment can achieve the bonding of all the conductive glues and the connection ports of the gate line through a single hot-melt process.

[0018] In an optional implementation, the diameter of the through hole is greater than the width of the gate line, and the difference between the two is greater than 0.1 mm.

[0019] In an optional implementation, the transparent conductive layer is configured as a transparent conductive oxide thin film layer, and the transparent conductive oxide thin film layer is connected to the transparent substrate through a coating process.

[0020] In an optional embodiment, the through hole is formed by a laser scribing process.

[0021] In an optional implementation, the diameter of the conductive portion is greater than the width of the gate line, and the difference between the two is 0.05 mm-0.1 mm.

[0022] In an optional implementation, the height of the conductive portion is greater than the thickness of the back transparent insulating layer, and the difference between the height and the thickness is 10 micrometers to 40 micrometers.

[0023] In an optional implementation, it also includes:

[0024] Front panel;

[0025] A front insulating film layer, through which the second surface of each of the battery cells is connected to the front panel.

[0026] In a second aspect, the utility model provides an IBC photovoltaic cell, comprising any of the above-mentioned IBC photovoltaic cell packaging structures.

[0027] Beneficial effects:

[0028] The IBC photovoltaic cell provided in this embodiment can solve the problem that the silicon wafer is easily bent by heat when the IBC photovoltaic cell is welded. The derivation process of this beneficial effect is generally similar to the derivation process of the beneficial effect brought by the above-mentioned IBC photovoltaic cell packaging structure, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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 creative work.

[0030] Figure 1 This is a schematic diagram of an IBC photovoltaic cell packaging structure according to an embodiment of the utility model.

[0031] Description of reference numerals:

[0032] 11. back panel; 111. conductive portion; 112. first surface of the back panel;

[0033] 12. back transparent insulating layer; 121. first surface of the back transparent insulating layer; 122. second surface of the back transparent insulating layer;

[0034] 13. Battery cell; 131. First side of the battery cell; 132. Second side of the battery cell;

[0035] 14. Front insulating film layer; 15. Front panel. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0037] In the related art, since the positive and negative electrodes of IBC photovoltaic cells are both set on the back of the cell, when IBC photovoltaic cells are connected by series welding, a complete welding ribbon is usually cut and cut to connect the positive and negative electrodes of two adjacent cells. Since the welding of IBC photovoltaic cells changes from double-sided welding to single-sided welding, the silicon wafer is easily bent by heat during single-sided welding, which increases the difficulty of the process.

[0038] In view of this, the present embodiment provides an IBC photovoltaic cell packaging structure and an IBC photovoltaic cell to solve the problem that silicon wafers are easily bent due to heat when the IBC photovoltaic cell is welded.

[0039] Combine the following Figure 1 , describing an embodiment of the utility model.

[0040] According to an embodiment of the present invention, on one hand, an IBC photovoltaic cell packaging structure is provided, including a back panel 11 , a back transparent insulating layer 12 , and a plurality of cells 13 .

[0041] The back panel 11 is arranged on the backlight side of the photovoltaic module. In some embodiments, the back panel 11 may be a transparent glass plate. The first surface 112 of the back panel 11 is provided with a circuit structure, and the first surface 112 of the back panel 11 refers to the side close to the battery cell 13. The circuit structure can be formed by a printing process or a plating process, that is, by a printing process or a plating process, a conductive material is formed on the first surface 112 of the back panel 11 according to a preset shape.

[0042] The first surface 121 of the back transparent insulating layer 12 is connected to the first surface 112 of the back panel 11. The back transparent insulating layer 12 has an insulating property. In some embodiments, the back transparent insulating layer 12 may be an insulating adhesive film, the first surface of which is bonded to the first surface 112 of the back panel 11, and the second surface of which is bonded to each battery cell 13.

[0043] The first surface 131 of each cell 13 is provided with a grid line, and the grid line includes a positive grid line and a negative grid line. The first surface 131 of the plurality of cells 13 is connected to the second surface 122 of the back transparent insulating layer 12. The first surface 131 of the cell 13 is the backlight side of the cell 13. The positive grid line and the negative grid line are arranged on the backlight side of the cell 13, which can effectively increase the light receiving area of ​​the light receiving side of the cell 13 and improve the power generation efficiency.

[0044] It should be noted that the cells 13 in the photovoltaic module need to be conductively connected to the circuit structure on the back panel 11, so that the current generated by each cell 13 can be collected and then led out through the circuit structure. In order to achieve the conductive connection between the cell 13 and the circuit structure, the first surface 112 of the back panel 11 is provided with a conductive part 111 corresponding to the positive grid line and the negative grid line of each cell 13, and the back transparent insulating layer 12 is provided with a through hole corresponding to the conductive part 111, and the conductive part 111 passes through the through hole, and one end of the conductive part 111 is electrically connected to the circuit structure, and the other end is electrically connected to the corresponding positive grid line and negative grid line, so that multiple cells 13 can lead out current through the circuit structure.

[0045] In addition, it should be noted that the first surface 112 of the back panel 11 is as follows: Figure 1 The upper surface of the back panel 11 shown in FIG. 1; the first surface 121 of the back transparent insulating layer 12 refers to the Figure 1 The lower surface of the back transparent insulating layer 12 is shown, and the second surface 122 of the back transparent insulating layer 12 is as shown in FIG. Figure 1 The upper surface of the back transparent insulating layer 12 shown; the first surface 131 of the battery cell 13 refers to Figure 1The lower surface of the battery cell 13 shown in FIG. 1 is a second surface 132 of the battery cell 13. Figure 1 The upper surface of the battery cell 13 shown. The distance between adjacent conductive parts 111 is relatively close. By providing a back transparent insulating layer 12, each conductive part 111 can be insulated to avoid the problem of short circuit caused by contact of the conductive parts 111. A through hole is provided on the back transparent insulating layer 12 for the conductive part 111 to pass through, so that the conductive part 111 can be electrically connected to the connection port of the positive and negative grid lines. In some embodiments, the through hole on the back transparent insulating layer 12 can be formed by a laser scribing process, and the laser scribing process can accurately and quickly form the above-mentioned through hole. The diameter of the through hole is greater than the grid line width, and the difference is greater than 0.1 mm, and the number of through holes corresponds to the number of positive and negative grid lines of the battery cell 13.

[0046] With such arrangement, the IBC photovoltaic cell packaging structure provided in this embodiment does not need to be welded with welding ribbons, thus avoiding the problem of the cell 13 being easily bent due to heat.

[0047] In a preferred embodiment, the back panel 11 includes a transparent substrate and a transparent conductive layer, the transparent conductive layer is arranged on the transparent substrate, and the circuit structure is formed by the transparent conductive layer. In addition, the back transparent insulating layer 12 is arranged as a transparent insulating film layer.

[0048] With this arrangement, light can also enter from the back of the photovoltaic module, thereby increasing the light-receiving area of ​​the photovoltaic module.

[0049] Of course, in other embodiments, the back panel 11, the transparent conductive layer or the back transparent insulating layer 12 may also adopt a non-transparent structure, so that the photovoltaic module can only receive light on one side.

[0050] In some embodiments, the transparent conductive layer can be formed by a transparent conductive material, and the transparent conductive layer can be formed on a transparent substrate by printing or plating. In some embodiments, the back panel 11 can specifically use TCO glass (glass coated with a transparent conductive oxide film), the thickness of the TCO glass is about 1.2-3 mm, and the TCO glass is coated with a transparent conductive layer arranged according to the circuit pattern structure, that is, the circuit structure is composed of a transparent conductive layer, and its thickness is 0.1-0.2 μm. The material of the transparent conductive layer includes low-resistance and high-transparent conductive film materials such as ITO (Sn: In2O3), FTO (F: SnO2), and IMO (Mo doped In2O3).

[0051] It should be noted that the graphic structure of the above circuit structure can be specifically set according to actual conditions. It only needs to be electrically connected to each battery cell 13 and be able to collect and output the current generated by each battery cell 13. Its specific graphic structure will not be repeated here.

[0052] In an optional embodiment, the conductive part 111 is made of conductive glue, which is disposed on the first surface 112 of the back panel 11 by printing. In some embodiments, the height of the conductive part 111 is greater than the thickness of the back transparent insulating layer 12, and the difference between the two is 10 microns to 40 microns. The diameter of the conductive part 111 is greater than the width of the positive grid line and the negative grid line, and the difference between the two is 0.05 mm to 0.1 mm. Such a configuration can ensure that the conductive part 111 can pass through the through hole of the back transparent insulating layer 12 and fully contact the connection port of the positive grid line or the negative grid line. In some embodiments, the thickness of the back transparent insulating layer 12 can be specifically 0.45 to 0.55 mm.

[0053] In some embodiments, the conductive adhesive used to form the conductive portion 111 is a material with good conductivity, and may be a composite material formed by mixing metal copper, silver, aluminum, or copper, silver, aluminum, etc. in different proportions with resin.

[0054] The conductive glue is arranged on the first surface 112 of the back panel 11 by printing, which improves the arrangement accuracy and efficiency of the conductive glue. When the conductive glue is electrically connected to the battery cell 13, it is only necessary to contact the conductive glue with the connection ports of the positive and negative grid lines of the battery cell 13 and heat the conductive glue. Then, the conductive glue can be electrically connected to the connection ports of the positive and negative grid lines by hot melting, which effectively improves the connection efficiency.

[0055] In an optional embodiment, the conductive adhesive is connected to the positive grid wire and the negative grid wire through a hot melt process. With such a configuration, the conductive adhesive can be quickly connected to the connection ports of the positive grid wire and the negative grid wire through a hot melt process. During processing, after each conductive adhesive is aligned with the corresponding connection ports of the positive grid wire and the negative grid wire, the conductive adhesive can be melted by heating the assembly as a whole, and pressure is applied to press the conductive adhesive and the connection ports of the positive grid wire and the negative grid wire, thereby bonding the conductive adhesive in the hot melt state to the connection ports. Compared with the prior art in which the welding strips and the battery cells are welded one by one, the technical solution provided in this embodiment can achieve bonding of all the conductive adhesives to the connection ports of the positive grid wire and the negative grid wire through a single hot melt process.

[0056] In an optional embodiment, the IBC photovoltaic cell packaging structure also includes a front panel 15 and a front insulating film layer 14. The front panel 15 can be made of transparent glass, and the front insulating film layer 14 is made of a transparent insulating film material to allow light to enter the cell 13. The front insulating film layer 14, the second surface 132 of each cell 13 is connected to the front panel 15 through the front insulating film layer 14. In some embodiments, the front insulating film layer 14 can be made of a transparent insulating adhesive film to play the role of bonding the front panel 15 and the cell 13, and its thickness can be 0.1mm. The front panel 15 can be made of conventional transparent glass, and its thickness can be 2-5mm.

[0057] In an optional implementation, the implementation method of the IBC photovoltaic cell packaging structure may include the following steps:

[0058] Step 1: transport the front panel 15 to the workbench, and then transport the front insulating film layer 14 to the workbench and cover the upper surface of the front panel 15;

[0059] Step 2: transport a group of battery cells 13 to a workbench, and place the battery cells 13 with the back side of the grid lines printed facing upwards, in parallel and at regular intervals, on the front insulating film layer 14;

[0060] Step 3: transport the TCO glass to a workbench, and print conductive adhesive paste on the TCO film layer circuit connection points on the surface of the TCO glass by screen printing conductive paste, and further preheat the conductive adhesive to form a semi-cured state;

[0061] Step 4: Use laser scribing to scribble through holes on the back transparent insulating layer 12, the number and position of the through holes corresponding to the connection port position of the grid line of the battery cell 13 and the TCO film layer circuit connection point of the TCO glass;

[0062] Step 5: The back transparent insulating layer 12 with through holes is transported to a workbench and covered on the surface of the TCO glass printed with the conductive glue. The through hole position of the back transparent insulating layer 12 is aligned with the TCO film layer circuit connection point of the TCO glass. At the same time, the conductive glue passes through the through hole of the back transparent insulating layer 12 and still protrudes a certain height of the thickness of the back transparent insulating layer 12 after filling the through hole.

[0063] Step 6: After the conductive glue is printed, the conductive glue is preheated and glued together so that the back transparent insulating layer 12 and the TCO glass form an effective bond;

[0064] Step 7: Flip the TCO glass covered with the back transparent insulating layer 12: with the back transparent insulating layer 12 facing downward, and transport it to the workbench to be combined with the front panel 15 with the battery cells 13 laid thereon;

[0065] Step 8: Install the laminated photovoltaic cell assembly into a fixed frame and transport it to a laminating machine for lamination, so that the conductive adhesive is completely cured to form a fixed connection with the connection port of the electrode grid line and the connection point of the TCO film layer circuit.

[0066] Step 9: After lamination, the components will be installed with metal frames, sealed with glue, and the junction box will be welded.

[0067] The IBC photovoltaic cell packaging structure provided in this embodiment uses conductive glue, TCO conductive film and the grid line of the cell 13 to form a connection circuit to replace the traditional interconnection welding strip cell 13 connection method. The welding tension is small, the amount of conductive silver paste used is reduced, the material cost is reduced, and the operation is simpler, which is suitable for production and manufacturing.

[0068] In a second aspect, the present embodiment further provides an IBC photovoltaic cell, including any of the above-mentioned IBC photovoltaic cell packaging structures. The IBC photovoltaic cell provided in this embodiment can solve the problem that the silicon wafer is easily bent by heat when the IBC photovoltaic cell is welded. The derivation process of this beneficial effect is generally similar to the derivation process of the beneficial effect brought about by the above-mentioned IBC photovoltaic cell packaging structure, and will not be repeated here.

[0069] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. An IBC photovoltaic cell packaging structure, characterized in that: include: A back panel (11) comprising a transparent substrate and a transparent conductive layer, wherein the transparent conductive layer is arranged on the transparent substrate and forms a circuit structure; A back transparent insulating layer (12), a first surface of which is connected to the first surface (112) of the back panel (11); A plurality of battery cells (13), each of the first surfaces (131) of the battery cells (13) being provided with a grid line, and the first surfaces (131) of the plurality of battery cells (13) being connected to the second surface (122) of the back transparent insulating layer (12); wherein: A conductive portion (111) corresponding to the gate line of each of the battery cells (13) is provided on the first surface (112) of the back panel (11), and a through hole corresponding to the conductive portion (111) is provided on the back transparent insulating layer (12). The conductive portion (111) passes through the through hole, and one end of the conductive portion (111) is electrically connected to the circuit structure, and the other end is electrically connected to the connection port of the corresponding gate line, so that the plurality of battery cells (13) output current through the circuit structure.

2. The IBC photovoltaic cell packaging structure according to claim 1, characterized in that: The conductive part (111) is made of conductive glue, and the conductive glue is arranged on the first surface (112) of the back panel (11) by printing.

3. The IBC photovoltaic cell packaging structure according to claim 2, characterized in that: The conductive adhesive is connected to the connection port of the gate line through a hot-melt process.

4. The IBC photovoltaic cell packaging structure according to claim 1, characterized in that: The diameter of the through hole is greater than the width of the gate line, and the difference between the two is greater than 0.1 mm.

5. The IBC photovoltaic cell packaging structure according to claim 4, characterized in that: The transparent conductive layer is configured as a transparent conductive oxide thin film layer, and the transparent conductive oxide thin film layer is connected to the transparent substrate through a coating process.

6. The IBC photovoltaic cell packaging structure according to claim 1, characterized in that: The through holes are formed by a laser scribing process.

7. The IBC photovoltaic cell packaging structure according to claim 1, characterized in that: The diameter of the conductive part (111) is greater than the width of the gate line, and the difference between the two is 0.05 mm-0.1 mm.

8. The IBC photovoltaic cell packaging structure according to claim 1, characterized in that: The height of the conductive part (111) is greater than the thickness of the back transparent insulating layer (12), and the difference between the two is 10 micrometers to 40 micrometers.

9. The IBC photovoltaic cell packaging structure according to claim 1, characterized in that: Also includes: Front panel (15); A front insulating film layer (14), wherein the second surface (132) of each of the battery cells (13) is connected to the front panel (15) via the front insulating film layer (14).

10. An IBC photovoltaic cell, characterized in that: The invention comprises the IBC photovoltaic cell packaging structure as described in any one of claims 1 to 9.

Images