Novel heat-spot-resistant crystalline silicon photovoltaic module

Abstract

The utility model discloses a novel heat-spot-resistant crystalline silicon photovoltaic module, which comprises a back plate, a back adhesive film, a front adhesive film, a front plate, a flexible circuit board and a plurality of solar cells, the front adhesive film covers the front surfaces of the solar cells, the back adhesive film covers the back surfaces of the solar cells and then is clamped between the front plate and the back plate, the front plate and the front adhesive film are made of transparent materials, and the flexible circuit board is clamped between the front plate and the back plate. The flexible circuit board is located between the back of the solar cells and the back adhesive film, and all the solar cells are connected in series; the flexible circuit board comprises a diode area and a battery connecting area, the diode area is located at the edge position of the periphery of the solar battery, the first electrode is electrically connected with a copper exposing area of the battery connecting area, the copper exposing area is electrically connected with a welding spot of the diode area through an inner layer route of the flexible circuit board, and a plurality of diodes are welded to the welding spot of the diode area. Namely, each solar cell is in reverse bias connection with one diode. According to the scheme, the diode is implanted into the photovoltaic power generation assembly through modularization processing, and hot spot prevention processing is carried out on the photovoltaic assembly.

Description

Technical Field

[0001] This utility model relates to the field of solar power generation equipment, and in particular to a novel heat-resistant crystalline silicon photovoltaic module. Background Technology

[0002] With the rapid development of photovoltaic technology, crystalline silicon photovoltaic modules face a serious challenge from the hot spot effect during long-term outdoor operation. The hot spot effect can cause a sharp increase in local temperature, leading to aging of encapsulation materials, damage to solar cells, and even the risk of fire.

[0003] Patent document CN201621427386.5 discloses a bifacial photovoltaic module resistant to heat spot effects. It uses conductive adhesive to connect diodes side-by-side between cells to form a heat spot-resistant module. However, its drawbacks are: 1. Wires are needed to connect the cells, and space needs to be reserved in the cell string to place the diodes, reducing the effective power generation area of ​​the photovoltaic module; 2. When a heat spot occurs, the bypass diodes become conductive and generate heat. Prolonged heating can cause the adhesive film in the surrounding area to melt, potentially leading to delamination and affecting the cells at the diode edges; 3. The connection between the conductive metal strip and the conductive adhesive requires heat treatment at temperatures exceeding 120 degrees Celsius, which can cause secondary stress between the edge cells, increasing the likelihood of cell breakage. Summary of the Invention

[0004] This invention primarily addresses the technical problems of existing technologies, such as diodes occupying battery space and reducing power generation area, and diode heating affecting connection and battery cells. It provides a novel heat-resistant crystalline silicon photovoltaic module that does not occupy conventional power generation area and whose heat generation does not affect battery cells.

[0005] The present invention addresses the above-mentioned technical problems mainly through the following technical solution: A novel heat-resistant crystalline silicon photovoltaic module includes a back sheet, a back film, a front film, a front panel, a flexible circuit board, and several solar cells. The solar cells are connected in series by interconnecting strips. The front of the solar cells is covered with a front film, and the back is covered with a back film, and then sandwiched between the front panel and the back panel. Both the front panel and the front film are made of transparent material. The flexible circuit board is located between the back of the solar cells and the back film. The first electrode of the solar cells is located on the back, and the second electrode is located on the front. All solar cells are connected in series. The first electrode of the solar cell at the head and the second electrode of the solar cell at the tail serve as the output terminals of the entire photovoltaic module and are connected to the external circuit.

[0006] The flexible circuit board includes a diode area and a battery connection area. The diode area is located at the edge of the solar cell. The battery connection area has an exposed copper area below the first electrode of each solar cell. The first electrode is electrically connected to the corresponding exposed copper area. The exposed copper area is electrically connected to the solder joint of the diode area through the inner layer of the flexible circuit board. Several diodes are soldered on the solder joint of the diode area, that is, each solar cell is connected to a diode in reverse bias.

[0007] This solution employs modular processing to embed diodes into photovoltaic (PV) modules, providing heat-spot protection. The diodes are biased, and conductive adhesive allows for pre-connection to the FPC (Flexible Printed Circuit) solder joints (formed through printing, spraying, and reflow soldering), creating an FPC with integrated diodes. Modular, multi-stage production is suitable for assembly line operations. Furthermore, the diodes are located on the periphery of the solar panel, so their heat generation does not affect the solar cells or reduce the available power generation area.

[0008] Preferably, the diode is a Schottky diode. If the solar panel is P-type, the first electrode is the negative electrode; if the solar panel is N-type, the first electrode is the positive electrode. In this design, a low-Vf Schottky diode is selected.

[0009] Preferably, the distance between the diode and any solar cell is greater than 2 cm. This distance ensures that when the module is operating outdoors, the heat generated by the diode due to the hot spot effect will not affect the solar cells.

[0010] Preferably, the diode is connected to the solder joint using conductive adhesive; the exposed copper area is connected to the first electrode using copper foil conductive adhesive tape. The copper foil conductive adhesive avoids thermal stress and eliminates the need for complex soldering processes, thus reducing production costs.

[0011] Preferably, the flexible circuit board is made of high-temperature resistant PET or high-temperature resistant PI material, and the color is black, transparent, yellow, etc.

[0012] Preferably, the diode region is covered with a graphene thermal conductive layer, which is tightly bonded to the diode. The surface of the graphene thermal conductive layer consists of a micro-fin array with a height of 0.5-1 mm and a fin spacing of 2-3 mm. The graphene thermal conductive layer can quickly absorb and disperse the heat from the diode, which is then dissipated through the micro-fin array, extending the component's lifespan.

[0013] Preferably, a transition layer is deposited on the surface of the first electrode. The transition layer is a copper-tin alloy and is electrically connected to the exposed copper area through a copper foil conductive tape.

[0014] The transition layer is deposited on the surface of the battery electrode via magnetron sputtering, and its surface roughness forms a mechanical interlock with the bonding surface of the copper foil conductive tape. The transition layer can reduce contact resistance, effectively improve thermal stress resistance, and give the module a long service life.

[0015] The beneficial effects of this invention are that it can effectively control the hot spot effect, and the heat generated by the diodes will not affect the solar cell or occupy area. The centralized arrangement of diodes facilitates the installation of a heat dissipation layer, thereby achieving a good heat dissipation effect. Attached Figure Description

[0016] Figure 1 This is a side view of a novel heat-resistant crystalline silicon photovoltaic module according to this utility model;

[0017] Figure 2 yes Figure 1 Enlarged view of region A in the middle;

[0018] Figure 3 This is a schematic diagram of a flexible circuit board structure according to the present invention;

[0019] In the diagram: 1. Solar cell, 2. Flexible circuit board, 3. First electrode, 4. Second electrode, 5. Back adhesive film, 6. Front adhesive film, 7. Front plate, 8. Back plate, 9. External wire, 10. Diode area, 11. Solder joint, 12. Exposed copper area, 13. Diode. Detailed Implementation

[0020] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0021] Example: A novel heat-resistant crystalline silicon photovoltaic module according to this example, such as... Figure 1 and Figure 2 As shown, the photovoltaic module includes a backplate 8, a back adhesive film 5, a front adhesive film 6, a front panel 7, a flexible circuit board 2, and six solar cells 1. The solar cells are connected in series by interconnecting strips. The front of the solar cells is covered with a front adhesive film, and the back is covered with a back adhesive film. The solar cells are then sandwiched between the front panel and the backplate. Both the front panel and the front adhesive film are made of transparent material. The flexible circuit board is located between the back of the solar cells and the back adhesive film. The first electrode 3 of the solar cells is located on the back, and the second electrode 4 is located on the front. All the solar cells are connected in series. The first electrode of the solar cell at the head and the second electrode of the solar cell at the tail serve as the output terminals of the entire photovoltaic module and are connected to an external circuit through an external wire 9.

[0022] like Figure 3As shown, the flexible circuit board includes a diode area 10 at the top and a battery connection area at the bottom. The diode area is located at the edge of the solar cell. The battery connection area has an exposed copper area 12 below the first electrode of each solar cell. The first electrode is electrically connected to the corresponding exposed copper area. The exposed copper area is electrically connected to the solder joint of the diode area through the inner layer route of the flexible circuit board. Several diodes 13 are soldered on the solder joint 11 of the diode area, that is, each solar cell is connected to a diode in reverse bias.

[0023] This solution employs modular processing to embed diodes into photovoltaic (PV) modules, providing heat-spot protection. The diodes are biased, and conductive adhesive allows for pre-connection to the FPC (Flexible Printed Circuit) solder joints (formed through printing, spraying, and reflow soldering), creating an FPC with integrated diodes. Production is modular and process-by-process, suitable for assembly line operations.

[0024] The diode is a Schottky diode. If the solar panel is P-type, the first electrode is the negative electrode; if the solar panel is N-type, the first electrode is the positive electrode. In this design, a low-Vf Schottky diode is selected.

[0025] The diode is placed at a distance greater than 2 cm from any solar cell. This distance ensures that when the module is operating outdoors, the heat generated by the diode due to the hot spot effect will not affect the solar cells.

[0026] The diode is connected to the solder joint using conductive adhesive; the exposed copper area is connected to the first electrode using copper foil conductive adhesive tape. The copper foil conductive adhesive avoids thermal stress and eliminates the need for complex soldering processes, thus reducing production costs.

[0027] The flexible circuit board is made of high-temperature resistant PET or high-temperature resistant PI material, and its colors include black, transparent, and yellow.

[0028] The diode region is covered with a graphene thermal conductive layer, which is tightly bonded to the diode. The surface of the graphene thermal conductive layer consists of a micro-fin array with a height of 0.5-1 mm and a fin spacing of 2-3 mm. The graphene thermal conductive layer can quickly absorb and disperse the heat from the diode, which is then dissipated through the micro-fin array, extending the component's lifespan.

[0029] A transition layer is deposited on the surface of the first electrode. The transition layer is a copper-tin alloy and is electrically connected to the exposed copper area through a copper foil conductive tape.

[0030] The transition layer is deposited on the surface of the battery electrode via magnetron sputtering, and its surface roughness forms a mechanical interlock with the bonding surface of the copper foil conductive tape. The transition layer can reduce contact resistance, effectively improve thermal stress resistance, and give the module a long service life.

[0031] This solution can effectively control the hot spot effect, and the heat generated by the diodes will not affect the solar cells or occupy space. The centralized arrangement of diodes facilitates the installation of heat dissipation layers, thereby achieving a good heat dissipation effect.

[0032] The specific embodiments described herein are merely illustrative examples illustrating the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the principles of this invention or exceeding the scope defined by the appended claims.

[0033] Although this document uses terms such as flexible circuit board, first electrode, and diode region frequently, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of this invention; interpreting them as any additional limitation would contradict the spirit of this invention.

Claims

1. A novel hot spot resistant crystalline silicon photovoltaic module, characterized in that, The solar module comprises a back plate, a back adhesive film, a front adhesive film, a front plate, a flexible circuit board and a plurality of solar cells, the solar cells are welded in series through interconnection strips, the solar cells are clamped between the front plate and the back plate after the front of the solar cells is covered with the front adhesive film and the back of the solar cells is covered with the back adhesive film, the front plate and the front adhesive film are both transparent materials, the flexible circuit board is located between the back of the solar cells and the back adhesive film, the first electrode of the solar cells is located at the back, and the second electrode of the solar cells is located at the front, all the solar cells are connected in series, the first electrode of the solar cell at the head and the second electrode of the solar cell at the tail are connected with an external circuit as output terminals of the entire photovoltaic module. The flexible circuit board comprises a diode area and a cell connection area, the diode area is located at the edge of the periphery of the solar cell, the cell connection area is provided with a copper-exposed area below the first electrode of each solar cell, the first electrode is electrically connected with the corresponding copper-exposed area, the copper-exposed area is electrically connected with the welding point of the diode area through an inner layer route of the flexible circuit board, and a plurality of diodes are welded on the welding point of the diode area, that is, each solar cell is reversely biased and connected with a diode.

2. The novel hot spot resistant crystalline silicon photovoltaic module of claim 1, wherein, The diode is a Schottky diode, the first electrode is a negative electrode if the solar cell panel is P-type, and the first electrode is a positive electrode if the solar cell panel is N-type.

3. The novel hot spot resistant crystalline silicon photovoltaic module according to claim 1 or 2, characterized in that, The distance between the diode and any solar cell is greater than 2 cm.

4. The novel hot spot resistant crystalline silicon photovoltaic module of claim 3, wherein, The diode and the welding point are connected through conductive adhesive, and the copper-exposed area and the first electrode are connected through a copper foil conductive adhesive tape.

5. The novel hot spot resistant crystalline silicon photovoltaic module of claim 1, wherein, The flexible circuit board is made of high-temperature-resistant PET or high-temperature-resistant PI material.

6. The novel hot spot resistant crystalline silicon photovoltaic module of claim 1, wherein, The diode area is covered with a graphene heat conduction layer, the graphene heat conduction layer is closely attached to the diode, the surface of the graphene heat conduction layer is provided with a micro-fin array with a height of 0.5-1 mm, and the spacing of the fins is 2-3 mm.

7. The novel hot spot resistant crystalline silicon photovoltaic module of claim 1, wherein, The surface of the first electrode is deposited with a transition layer, the transition layer is a copper-tin alloy, and the transition layer is electrically connected with the copper-exposed area through a copper foil conductive adhesive tape.

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