A photovoltaic module and photovoltaic system

Abstract

The application is suitable for the technical field of solar cells, and particularly relates to a photovoltaic module and a photovoltaic system. The photovoltaic module comprises a plurality of cell pieces, each of which comprises a substrate, a grid line and a solder pad arranged on the substrate, and at least two solder paste stacks arranged on the solder pad. The adjacent solder paste stacks are not in contact, and the opposite sides of any two adjacent solder paste stacks are provided with notches. The opposite sides of the adjacent two solder paste stacks are provided with notches, so that the interval between the adjacent solder paste stacks is increased, the adjacent solder paste stacks will not be connected and gathered together during solidification, the height of the solder paste stack is effectively ensured, and the welding yield with the solder strip is ensured.

Description

Technical Field

[0001] This application belongs to the field of solar cell technology, and particularly relates to a photovoltaic module and a photovoltaic system. Background Technology

[0002] A solar cell has a main grid connected to a fine grid. The fine grid is densely distributed on the surface of the cell and its main function is to collect photogenerated carriers. The main grid's main function is to collect the current collected by the fine grid and connect the cells in series through interconnecting bars.

[0003] The main gate has pads formed by printed solder paste. Currently, the pads use two oval-shaped solder paste shapes, such as... Figure 1 As shown, during curing, the two oval solder pastes tend to clump together, resulting in a reduced height of the cured solder paste. This can lead to poor soldering pull and other defects when soldering with solder ribbons. Utility Model Content

[0004] This application provides a photovoltaic module designed to address the problem of poor soldering pull caused by the two elliptical solder pastes of existing photovoltaic modules easily agglomerating together.

[0005] The embodiments of this application are implemented as follows: a photovoltaic module is provided, including a plurality of solar cells, wherein the solar cells include:

[0006] Base;

[0007] The gate lines and pads are set on the substrate; and

[0008] At least two solder paste piles are placed on the pads;

[0009] Adjacent solder paste stacks do not contact each other, and a notch is provided on the opposite side of any two adjacent solder paste stacks.

[0010] Furthermore, at least two solder paste piles are identical in shape and / or size.

[0011] Furthermore, the width between the gaps between two adjacent solder paste piles ranges from 0.05 mm to 0.1 mm.

[0012] Furthermore, the edge of the gap is at least one of a straight line, a curve, or a wavy line.

[0013] Furthermore, the top of the solder paste stack has a rough texture.

[0014] Furthermore, the rough structure consists of several solder paste bumps.

[0015] Furthermore, the contact surface between the solder paste buildup and the pad is an incomplete ellipse with missing edges.

[0016] Furthermore, the length of the major semi-axis of the incomplete ellipse ranges from 0.2 mm to 0.6 mm, and the length of the minor semi-axis of the incomplete ellipse ranges from 0.1 mm to 0.3 mm.

[0017] Furthermore, it also includes busbars, which are used to solder to solder paste stacks to connect several battery cells in series and parallel.

[0018] Secondly, this application also provides a photovoltaic system, including the photovoltaic module as described above.

[0019] The beneficial effects of this application are as follows: The photovoltaic module provided by this application includes a plurality of solar cells, each solar cell including a substrate; grid lines and pads disposed on the substrate; and at least two solder paste stacks disposed on the pads; adjacent solder paste stacks do not contact each other, and a notch is provided on the opposite side of any two adjacent solder paste stacks. By providing a notch on the opposite side of two adjacent solder paste stacks, the spacing between adjacent solder paste stacks is increased, preventing adjacent solder paste stacks from connecting and clumping together during curing, effectively ensuring the height of the solder paste stacks, and thus ensuring the soldering yield with the solder ribbon. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of an elliptical solder paste stack provided by existing technology;

[0021] Figure 2 This is a schematic diagram of the symmetrical structure of two solder paste stacks in one embodiment of the photovoltaic module provided in this application;

[0022] Figure 3 This is a schematic diagram of an embodiment of the photovoltaic module provided in this application, showing an asymmetrical structure with two solder paste stacks.

[0023] Figure 4 This is a schematic diagram of a photovoltaic module according to an embodiment of the present application, where the boundary between the solder paste pile and the blank area is a straight line;

[0024] Figure 5 This is a schematic diagram of a photovoltaic module embodiment provided in this application, where the boundary between the solder paste pile and the blank area is a wavy line;

[0025] Figure 6 This is a schematic diagram of a photovoltaic module according to an embodiment provided in this application, where the boundary between the solder paste pile and the blank area is a segmented straight line;

[0026] Figure 7 This is a schematic diagram of a photovoltaic module embodiment provided in this application, showing that the boundary between the solder paste pile and the blank area is a combination of wavy lines and straight lines;

[0027] Figure 8 This is a schematic diagram of a photovoltaic module embodiment provided in this application, showing a rough structure for the solder paste stack.

[0028] Explanation of reference numerals in the attached figures:

[0029] 100 - Solder paste pile, 110 - Solder paste bump, 200 - Blank area. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application.

[0031] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0033] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0034] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference values ​​and / or reference letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0036] The photovoltaic module provided in this application includes a plurality of solar cells, each solar cell comprising a substrate; grid lines and pads disposed on the substrate; and at least two solder paste stacks disposed on the pads; adjacent solder paste stacks are not in contact with each other, and a notch is provided on the opposite side of any two adjacent solder paste stacks. By providing a notch on the opposite side of two adjacent solder paste stacks, the spacing between adjacent solder paste stacks is increased, preventing adjacent solder paste stacks from clumping together during curing, effectively ensuring the height of the solder paste stacks, and thus ensuring the soldering yield with the solder ribbon.

[0037] like Figures 2 to 8 As shown in the figure, this application provides a photovoltaic module, including a plurality of solar cells, the solar cells including:

[0038] Substrate (not shown in the figure);

[0039] Gate lines and pads (not shown) are set on the substrate; and

[0040] At least two solder paste piles 100 on the pads;

[0041] Adjacent solder paste stacks 100 do not contact each other, and any two adjacent solder paste stacks 100 have a notch on their opposite sides.

[0042] Solar cells are the basic building blocks of photovoltaic modules, primarily used to convert light energy into electrical energy.

[0043] In practice, the manufacturing process of solar cells includes, but is not limited to, incoming material inspection, texturing, diffusion process, etching, ALD coating, PECVD deposition, screen printing, and testing.

[0044] Incoming material inspection refers to unpacking the delivered ingots and carefully inspecting their quality.

[0045] Texturing processes create a textured surface on the silicon wafer, reducing the reflectivity of the solar cells and improving efficiency.

[0046] The diffusion process involves permeating a layer of phosphorus onto the surface of P-type silicon to form a PN junction, providing the basic structure for the solar panel.

[0047] Etching is a process that precisely removes phosphorus from the edges of silicon wafers to prevent short circuits and reduce parallel resistance.

[0048] ALD coating is a thin film deposited on the surface of silicon wafers to enhance the performance of solar panels.

[0049] PECVD deposition refers to the use of plasma-enhanced chemical vapor deposition to further optimize the structure of solar panels.

[0050] Screen printing is used to collect current and create electrodes for solar cells, ensuring smooth current flow.

[0051] The testing process involves comprehensive testing of the solar panels, such as using the aforementioned solar cell performance testing equipment to perform electrical performance testing, environmental adaptability testing, safety testing, and mechanical performance testing on the cells.

[0052] Typically, a solar cell has several regions with different polarities, and these regions are equipped with fine grids. The fine grids converge to the main grid, which is connected to several pads. At least two solder paste stacks 100 are placed on the aforementioned pads.

[0053] Solder paste stack 100 is formed by solder paste printing and stacking. The surface of the pad can be regarded as the printing surface. In practice, solder paste can be printed onto the surface of the pad using a printing stencil. The stencil has perforations. Solder paste is printed onto the printing surface through the perforations by scraping or spraying, thereby forming solder paste stack 100.

[0054] The base of a traditional solder paste stack 100 is a complete oval shape, such as... Figure 1 As shown.

[0055] At least two solder paste piles 100 are placed on the pad, and the at least two solder paste piles 100 do not contact each other, that is, there is a blank area 200 between two adjacent solder paste piles 100. Furthermore, there is a notch on the opposite side between two adjacent solder paste piles 100. In other words, the close-approaching portions of two adjacent solder paste piles 100 are removed to form a notch. Therefore, the projection of the solder paste pile 100 onto the pad surface is not a complete ellipse, but rather an ellipse with a notch. That is, the contact surface between the solder paste pile 100 and the pad is an incomplete ellipse with a missing edge, thereby increasing the spacing between two adjacent solder paste piles 100. Figure 2 As shown, due to the increased spacing between two adjacent solder paste piles 100, the two adjacent solder paste piles 100 will not come into contact with each other and clump together when the solder paste is cured. Therefore, no solder paste will flow between the two adjacent solder paste piles 100, which can ensure the height of the solder paste piles 100, thereby ensuring the yield of subsequent soldering, while also reducing the amount of solder paste used and saving costs.

[0056] In some alternative embodiments, taking the printing of solder paste on the surface of the pads by a printing stencil to form a solder paste pile 100 as an example, the printing stencil itself is provided with a pad printing area, the pad printing area has at least two printed patterns distributed at intervals, and a printing blocking area is provided on the opposite side of two adjacent printed patterns. The printing blocking area is used to form a gap in the printed solder paste pile 100.

[0057] A printing stencil is typically made of a stainless steel sheet and is a key tool in SMT (Surface Mount Technology) processes used to precisely print solder paste onto designated locations. The surface of the printing stencil is laser-cut to form a precise array of openings, with the size and position of the openings strictly corresponding to the required pad design.

[0058] When printing solder paste, the printing stencil plays a role in precise positioning. By precisely aligning the openings with the surface of the pads, and with the help of a squeegee, the solder paste is evenly printed onto the target surface, forming a solder paste layer of uniform thickness, ensuring that the solder paste is deposited only in the areas that need to be soldered.

[0059] The solder pad printing area has at least two printed patterns, which are spaced apart, meaning that the printed patterns are not connected, thus ensuring that the printed solder paste stacks 100 do not contact each other. Each printed pattern has several mesh openings that allow solder paste to pass through. A printing blocking area is provided on the opposite side of two adjacent printed patterns; this blocking area has no mesh openings and therefore cannot allow solder paste to pass through, creating gaps in the printed solder paste stacks 100.

[0060] Optionally, the number of solder paste stacks 100 is greater than or equal to 2. For example, the number of solder paste stacks 100 is 3, 4, 5 or more than 5, without limitation.

[0061] Optionally, the multiple solder paste stacks 100 can be arranged in a straight line or in an array, without limitation.

[0062] In some embodiments, at least two solder paste piles 100 have different shapes and / or sizes. For example, taking two solder paste piles 100 distributed left and right as an example, the solder paste pile 100 on the left can be designed to be larger than the solder paste pile 100 on the right. Figure 3 As shown. Of course, in some other embodiments, the solder paste pile 100 on the right can also be designed to be larger than the solder paste pile 100 on the left, which will not be elaborated here.

[0063] Optionally, at least two solder paste piles 100 have the same shape and size. For example, two solder paste piles 100 have the same shape and size and are symmetrical, which makes it easier to print and manufacture the solder paste piles 100.

[0064] In some alternative embodiments, the length of the major semi-axis of the incomplete ellipse ranges from 0.2 mm to 0.6 mm. For example, the length of the major semi-axis of the incomplete ellipse can be designed to be any length from 0.3 mm, 0.4 mm, 0.5 mm or 0.2 mm to 0.6 mm, without limitation.

[0065] Optionally, the length of the minor semi-axis of the incomplete ellipse can range from 0.1 mm to 0.3 mm. For example, the length of the minor semi-axis of the incomplete ellipse can be designed to be any length from 0.15 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.25 mm, 0.28 mm or 0.1 mm to 0.3 mm, without limitation.

[0066] As one possible implementation, the edge of the notch is at least one of a straight line, a curve, or a wavy line. In practice, the edge of the notch can be considered as the boundary between the blank area 200 and the solder paste pile 100. For ease of understanding, the edge of the notch is denoted as D1. Figure 2 As shown.

[0067] For example, taking the boundary between the blank area 200 and the solder paste pile 100 as a straight line, such as... Figure 4 As shown.

[0068] It should be noted that the boundary between the blank area 200 and the solder paste pile 100 can be a straight line, which can be a single straight line or multiple straight lines. In other words, multiple straight lines can be considered as a broken line, such as... Figure 6 As shown.

[0069] Alternatively, the boundary between the blank area 200 and the solder paste pile 100 can also be a wavy line, such as... Figure 5 As shown. Of course, in some other embodiments, the boundary between the blank area 200 and the solder paste pile 100 can also be designed as a combination of wavy lines and straight lines, such as... Figure 7 As shown.

[0070] Optionally, the width range between the gaps of two adjacent solder paste piles 100 is B1, where 0.05 mm ≤ B1 ≤ 0.1 mm. For example, the width range between the gaps of two adjacent solder paste piles 100 can be designed to be any length from 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, or 0.05 mm to 0.1 mm, without limitation.

[0071] Optionally, the width between the gaps of two adjacent solder paste piles 100 refers to the minimum distance between two adjacent solder paste piles 100, that is, the minimum distance between the gaps of two adjacent solder paste piles 100. For example, taking the boundary between the blank area 200 and the solder paste pile 100 as a straight line, the distance between two adjacent straight lines is B1. Figure 4 As shown.

[0072] Optionally, when the boundary between the blank area 200 and the solder paste pile 100 is a curve, the distance between the two closest points on adjacent curves is B1, such as... Figure 2 and Figure 5 As shown, no further details will be provided.

[0073] The photovoltaic module provided in this application includes a plurality of solar cells, each solar cell including a substrate; grid lines and pads disposed on the substrate; and at least two solder paste piles 100 disposed on the pads; adjacent solder paste piles 100 are not in contact with each other, and a notch is provided on the opposite side of any two adjacent solder paste piles 100. By providing a notch on the opposite side of two adjacent solder paste piles 100, the spacing between adjacent solder paste piles 100 is increased, and adjacent solder paste piles 100 will not connect and clump together during curing, effectively ensuring the height of the solder paste piles 100, thereby ensuring the soldering yield with the solder ribbon.

[0074] In some alternative embodiments, the top of the solder paste pile 100 has a roughened structure, i.e., the side of the solder paste pile 100 away from the surface of the pad, such as... Figure 8 As shown. By providing a rough structure on the top of the solder paste stack 100, the friction on the top of the solder paste stack 100 can be increased. During subsequent soldering with solder ribbons, the solder ribbons can be prevented from shifting, thereby avoiding cold solder joints and short circuits, and further improving the soldering yield.

[0075] Optionally, the rough structure consists of several solder paste protrusions 110, making the top surface of the entire solder paste pile 100 have an undulating shape, thereby increasing the roughness of the top of the solder paste pile 100 and effectively preventing the solder strip from shifting when the solder paste pile 100 is soldered to the solder strip.

[0076] As one possible implementation, the photovoltaic module provided in this application also includes a busbar (not shown in the figure), which is used to weld to the solder paste stack 100 to connect several solar cells in series and parallel.

[0077] In practice, the busbar is the welding strip, and adjacent cells are connected in series and parallel through the busbar to form a battery module.

[0078] In some possible embodiments, the photovoltaic module further includes a front panel, an encapsulating film, and a back panel, wherein the solar cells, the front panel, the encapsulating film, and the back panel form a laminate, or the solar module, the front panel, the encapsulating film, and the back panel form a laminate.

[0079] The front panel is made of tempered glass or organic board with high light transmittance (generally above 91%), and its function is to protect the main power generation unit.

[0080] The adhesive film usually refers to EVA adhesive film, which is used to bond and fix the front panel and the generator body.

[0081] The main power generation component is the aforementioned battery cell, whose primary function is to generate electricity.

[0082] The backplate is used to support and protect the main power generation unit, providing sufficient mechanical strength, as well as good sealing and electrical insulation, etc., which will not be elaborated further.

[0083] Optionally, the photovoltaic module also includes a frame and a junction box, etc. The frame is used to connect to the edge of the solar cell and to mount the photovoltaic module to a bracket, wall, roof or other designated location.

[0084] A junction box is a connecting device between a solar cell array composed of photovoltaic modules and a solar charging control device. Its main function is to connect and protect the photovoltaic modules, connect the power generated by the photovoltaic modules to external lines, and conduct the current generated by the photovoltaic modules.

[0085] In some alternative embodiments, this application also provides a photovoltaic system, including the photovoltaic module as described above.

[0086] A photovoltaic system consists of solar panels, a controller, an inverter, and a battery.

[0087] Solar panels, also known as photovoltaic modules, directly convert sunlight into direct current (DC) electricity and are the core of the system's energy harvesting.

[0088] In practice, the controller's function is to intelligently regulate the charging and discharging process. For example, it employs PWM (Pulse Width Modulation) or MPPT (Maximum Power Point Tracking) technology to improve charging efficiency by 3%-6%, prevent overcharging or over-discharging of the battery, and extend its lifespan. Additionally, the controller also features temperature compensation, light / time control switches, and other auxiliary functions.

[0089] The function of a storage battery is to store electrical energy for use at night or on rainy days. Common types are lead-acid maintenance-free batteries and gel batteries, which are suitable for unattended scenarios.

[0090] Optionally, the battery needs to meet requirements such as strong deep discharge capability and low self-discharge rate, and the capacity design needs to match the system load and the number of consecutive rainy days.

[0091] The function of an inverter is to convert direct current (DC) into 220V / 110V alternating current (AC) for use by household appliances.

[0092] Optionally, inverters are available in stand-alone and grid-connected types. Grid-connected systems require dedicated inverters to match the grid frequency and voltage, with conversion efficiency exceeding 95%. Some integrated controller functions enable integrated management.

[0093] It should be noted that the photovoltaic system described above, consisting of solar panels, controller, inverter, and battery, is an illustrative example of the embodiments of this application and not a specific limitation of this application. In other embodiments, the photovoltaic system may also include other auxiliary components, such as support systems, combiner boxes, and distribution cabinets.

[0094] The support system is used to secure the solar panels and adjust the tilt angle to maximize light capture; the material must be corrosion-resistant (such as aluminum alloy).

[0095] The combiner box and distribution cabinet centrally manage the output of multiple solar panels to ensure stable current distribution.

[0096] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the structure and implementation principle of the photovoltaic system described above can be referred to the corresponding structure and implementation principle in the foregoing embodiments, and will not be repeated here.

[0097] The photovoltaic module provided in this application includes a plurality of solar cells, each solar cell including a substrate; grid lines and pads disposed on the substrate; and at least two solder paste piles 100 disposed on the pads; adjacent solder paste piles 100 are not in contact with each other, and a notch is provided on the opposite side of any two adjacent solder paste piles 100. By providing a notch on the opposite side of two adjacent solder paste piles 100, the spacing between adjacent solder paste piles 100 is increased, and adjacent solder paste piles 100 will not connect and clump together during curing, effectively ensuring the height of the solder paste piles 100, thereby ensuring the soldering yield with the solder ribbon.

[0098] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A photovoltaic module comprising a plurality of solar cells, characterized in that, The battery cell includes: Base, The gate lines and pads disposed on the substrate; and At least two solder paste piles are provided on the pads; Adjacent solder paste stacks do not contact each other, and any two adjacent solder paste stacks have a notch on opposite sides.

2. The photovoltaic module as described in claim 1, characterized in that, At least two of the solder paste piles are identical in shape and / or size.

3. The photovoltaic module as described in claim 1, characterized in that, The width between the gaps of two adjacent solder paste piles ranges from 0.05 mm to 0.1 mm.

4. The photovoltaic module as described in claim 1, characterized in that, The edge of the notch is at least one of a straight line, a curve, or a wavy line.

5. The photovoltaic module as described in claim 1, characterized in that, The top of the solder paste pile has a rough structure.

6. The photovoltaic module as described in claim 5, characterized in that, The rough structure consists of several solder paste protrusions.

7. The photovoltaic module as described in claim 1, characterized in that, The contact surface between the solder paste pile and the pad is an incomplete ellipse with missing edges.

8. The photovoltaic module as described in claim 7, characterized in that, The length of the major semi-axis of the incomplete ellipse ranges from 0.2 mm to 0.6 mm, and the length of the minor semi-axis of the incomplete ellipse ranges from 0.1 mm to 0.3 mm.

9. The photovoltaic module as described in claim 1, characterized in that, It also includes busbars for soldering to the solder paste stack to connect several of the solar cells in series and parallel.

10. A photovoltaic system, characterized in that, Includes photovoltaic modules as described in any one of claims 1 to 9.

Images