Photovoltaic power generation module, method for manufacturing the same, and photovoltaic power generation apparatus

Abstract

This invention provides a photovoltaic power generation module, a method for manufacturing the same, and a photovoltaic power generation device that improve the power output of the module by increasing the utilization rate of incident light, and further enhance the aesthetic appearance of the module. [Solution] By adjusting the refractive index of the adhesive unit 113 and the sealing layer 120 with respect to light, the characteristic value R is controlled to 0.014 to 0.118, thereby minimizing the reflection of incident light at the interface between the adhesive unit 113 and the surface film 121 of the sealing layer 120. By controlling the ratio Y of the height of the adhesive unit 113 to the thickness of the sealing layer 120 to Y ≤ 0.9, it is ensured that no air bubbles are formed between the adhesive unit 113 and the sealing layer 120 and in its main structure.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic power generation technology, and more specifically, to a photovoltaic module, a method for manufacturing the same, and a photovoltaic power generation device.

Background Art

[0002] The metal electrodes on the front and back surfaces of the battery cells are used to extract the internal current, and are divided into busbar electrodes and finger electrodes (also called thin electrodes, Finger). The busbar electrodes mainly play the role of aggregating and serially connecting the current of the finger electrodes. The finger electrodes are used to collect photo-generated carriers. The electrode pattern has evolved from the conventional 4BB, 5BB to MBB (Multiple-Busbar, 9 - 15 busbars), and further evolved to the SMBB technology (Super-Multiple Busbar, more than 16 busbars) which has become popular in recent years. In addition, the interconnect module technology using adhesives is an upgrade from the SMBB technology and has become one of the main trends in current research and development.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Adhesives have attracted attention as one of the important materials used in the interconnect module technology using adhesives. Commonly used adhesives are mainly divided into silicone-based adhesives, acrylic-based adhesives, and epoxy resin-based adhesives. The properties of the adhesives themselves, such as adhesive strength, yellowing performance, hardness, etc., all have a great impact on the performance of the module and are factors to be considered in the research and development of the prior art. In the actual process of research and development and prototyping, the printing quality of the adhesive, the number of adhesive points, the size of the adhesive points, etc. also affect the reliability of module manufacturing. For example, deformation of the adhesive points, reduction in the number and size of the adhesive points are likely to cause insufficient adhesive strength of the adhesive, and further affect the yield of the module.

[0004] In view of this, the present invention is proposed.

Means for Solving the Problem

[0005] An object of the present invention is to provide a photovoltaic module, a method for manufacturing the same, and a photovoltaic power generation device that improve the power generation amount of the module while ensuring the yield of the module and enhance the aesthetic appearance of the module.

[0006] The present invention is realized as follows. In a first aspect, the present invention provides a photovoltaic module, including a plurality of solar cell units and a plurality of conductive connection members, wherein adjacent solar cell units are electrically connected by the conductive connection members to form a cell string, and including a sealing layer adhered to the cell string, and an adhesive unit is further provided between the sealing layer and the cell string, and the adhesive unit adheres the conductive connection members to the solar cell units, The definition formula of the characteristic value R is represented by formula (1), The definition formula of the characteristic value Y is represented by formula (2),

Number

[0007] In an optional embodiment, the value of R is 0.020 to 0.097.

[0008] In an optional embodiment, the refractive index n1 of the adhesive unit with respect to light and the refractive index n2 of the sealing layer with respect to light satisfy n1 < n2.

[0009] In an optional embodiment, the adhesive unit is provided only on one side of the surface of the cell string or on both sides of the surface of the cell string. And / or, the adhesive unit is formed by curing the adhesive.

[0010] In the selected embodiment, the refractive index n1 of the adhesive unit with respect to light is 1.35 to 1.60, and the height of the adhesive unit is 50 to 280 μm. And / or, the adhesive used to form the adhesive unit is selected from at least one of silicone-based adhesives, acrylic-based adhesives, and epoxy resin-based adhesives.

[0011] In the selected embodiment, the refractive index n2 of the sealing layer with respect to light is 1.40 to 1.65, and the thickness of the sealing layer is 300 to 400 μm. and / or, the sealing layer is formed by laminating and crosslinking a sealing film selected from at least one of POE sealing film, EVA sealing film, and EPE sealing film.

[0012] In the chosen embodiment, the surface of the module is photographed with a camera, grayscale values ​​are obtained for different regions, and a characteristic value G is calculated. G = |g2 - g1| However, characteristic value G is a grayscale threshold, where g1 is the grayscale value of the region on the surface of the solar power generation module where no adhesive units exist, and g2 is the grayscale value of the region on the surface of the solar power generation module where adhesive units exist. The value of G satisfies G ≤ 20.

[0013] In the chosen embodiment, the adhesive unit covers the surface of the conductive connecting member at the location where the adhesive unit is present.

[0014] In the chosen embodiment, the adhesive unit is located between the conductive connecting member and the solar cell at the position where the adhesive unit is present, and the adhesive unit covers a portion of the surface of the conductive connecting member.

[0015] In the selected embodiment, conductive connecting members and adhesive units are provided on both the front and back surfaces of the solar cell, and the sealing layer includes a front film and a back film, the front film is in close contact with the surface of the battery string, and the back film is in close contact with the back surface of the battery string. At a minimum, the characteristic value R is between 0.014 and 0.118, and the ratio Y of the height of the adhesive unit to the thickness of the surface film is Y ≤ 0.9. And / or, the conductive connecting member is a solder strip.

[0016] In the selected embodiment, the multiple solar cells are arranged at intervals, and one side of a solar cell is connected to the back surface of an adjacent solar cell via a conductive connecting member.

[0017] In the optional embodiment, a front protective substrate and a back protective substrate are further included, the front protective substrate being in close contact with the end face of the front film away from the battery string, and the back protective substrate being in close contact with the end face of the back film away from the battery string.

[0018] In the chosen embodiment, the material of the surface protection substrate is glass. And / or, the material of the back protective substrate is selected from at least one of glass and polymer materials, wherein the polymer materials include polyethylene terephthalate, polyolefin copolymer, polyamide, polyvinyl fluoride, and polyvinylidene fluoride.

[0019] In a second aspect, the present invention provides a method for manufacturing a photovoltaic power generation module according to any one of the above embodiments, the manufacturing method comprising: arranging a conductive connecting member on at least one surface in the thickness direction of a plurality of solar cells; bonding the conductive connecting member and the solar cells with an adhesive unit to form a battery string; and sealing the battery string with a sealing layer. The defining formula for the characteristic value R is given by equation (1), The defining formula for the characteristic value Y is given by equation (2),

Number

[0020] In an alternative embodiment, a plurality of solar cell modules are arranged along a first direction. The finger electrode lines of the solar cell modules extend along a second direction, and the first direction and the second direction intersect. When installing the conductive connection member, the conductive connection member is laid along the first direction. A battery string is manufactured using a process in which soldering is performed after applying and curing an adhesive. Or, a battery string is manufactured using a process in which an adhesive is applied and cured after soldering.

[0021] In an alternative embodiment, the value of R is 0.020 to 0.097.

[0022] In an alternative embodiment, the refractive index n1 of the adhesive unit with respect to the light beam and the refractive index n2 of the encapsulation layer with respect to the light beam satisfy n1 < n2.

[0023] In a third aspect, the present invention provides a solar power generation device, which includes the solar power generation module according to any one of the above embodiments or the solar power generation module manufactured by the manufacturing method according to any one of the above embodiments. There are M solar power generation modules, and the M solar power generation modules are connected in series. M is an integer greater than or equal to 1.

Advantages of the Invention

[0024] The present invention has the following beneficial effects. Specifically, by adjusting the refractive index of the adhesive unit and the sealing layer with respect to light, and the thickness of the sealing layer and the height of the adhesive unit, the reflection intensity R when light rays enter the adhesive unit from the sealing layer is controlled to 0.014 to 0.118, thereby minimizing reflection of incident light at the interface between the adhesive unit and the adhesive film. By controlling the ratio Y of the height of the adhesive unit to the thickness of the sealing layer to Y ≤ 0.9, it is ensured that no air bubbles are formed between the adhesive unit and the sealing layer and in its main structure, thereby improving the utilization rate of incident light in the module and contributing to an increase in the module's power. In laminated modules, the outline of the adhesive unit is not visible during visual inspection, as it is hidden by the sealing layer, thus enhancing the aesthetic appearance of the module. Since the number and size of the adhesive units in the present invention can be kept the same as in the conventional invention, the adhesive strength of the adhesive is not reduced, and the yield of the module is ensured.

[0025] As a supplement, conventional technologies often focus on the strength of the adhesion of the adhesive unit, and do not address the problem of the presence of the adhesive unit (e.g., the adhesive point) affecting aesthetics. There is no conventional technology that focuses on how to make the outline of the adhesive unit invisible during visual inspection. The inventors of this invention creatively control the refractive index of the adhesive unit and the sealing layer with respect to light rays, so that the refractive index of both satisfies a specific relational equation, thereby achieving the technical effect of making the outline of the adhesive unit invisible during visual inspection.

[0026] Furthermore, the inventors have found that even when the characteristic value R satisfies 0.014 to 0.118, the bonding point may be visible during visual inspection. From the results of magnified detection experiments, the inventors hypothesized that air bubbles at the interface between the bonding unit or the bonding unit and the bonding film cause the above situation. When air bubbles appear on the surface or within the main structure of the bonding unit, the reflectivity at the interface between the bonding unit and the air bubbles increases significantly, making the bonding point visible during visual inspection and further affecting the aesthetics. In addition, the inventors have found that the height of the bonding unit and the thickness of the sealing layer have a clear effect on air bubbles inside the module. By adjusting the thickness of the sealing layer and the height of the bonding unit to a specific ratio, the inventors ensure the technical effect of making the outline of the bonding unit invisible during visual inspection. Based on the above, the inventors have unexpectedly discovered that the photovoltaic power generation module manufactured according to the present invention can further improve the power generation capacity of the photovoltaic power generation module while simultaneously making the outline of the bonding unit invisible during visual inspection.

[0027] In preferred embodiments, the present invention makes the refractive index n1 of the adhesive unit with respect to light rays smaller than the refractive index n2 of the sealing layer with respect to light rays. As light rays incident from the adhesive film to the adhesive unit enter from an optically dense medium to an optically sparse medium, and the refracted light moves away from the normal, more incident light can reach the surface of the battery cells, which is advantageous for further improving module power. To more clearly explain the technical proposals based on the embodiments of the present invention, the drawings necessary for describing the embodiments will be briefly described. The drawings described below are merely examples of some embodiments of the present invention and do not limit the scope of the claims. It is clear that those skilled in the art can obtain drawings of other embodiments based on these drawings without requiring any creative effort. [Brief explanation of the drawing]

[0028] [Figure 1] This is a schematic cross-sectional view of a module where the bonding point completely covers the solder strip. [Figure 2] This is a schematic diagram of a battery string structure. [Figure 3]This is a schematic diagram of the structure of a photovoltaic power generation module according to an example. [Figure 4] This is a partial schematic diagram of the structure of a photovoltaic power generation module according to an embodiment. [Figure 5] Schematic diagram of incident light ray propagation (n1 <n2)である。 [Figure 6] This is a schematic diagram of the propagation of an incident light ray (n1>n2). [Figure 7] This is a schematic diagram illustrating the formation of bubbles. [Figure 8] This is a schematic diagram showing how the bonding point completely covers the solder strip. [Figure 9] This is a schematic cross-sectional view of a module where the bonding points partially cover the solder strip. [Figure 10] This is a schematic diagram showing how the bonding point partially covers the solder strip. [Figure 11] This is a partially schematic diagram of the structure of a solar power generation module according to Comparative Example 1. [Modes for carrying out the invention]

[0029] To further clarify the objectives, technical solutions, and advantages of the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be described clearly and completely below. Unless otherwise specified in the embodiments, the procedures will be carried out under normal conditions or conditions recommended by the manufacturer. Unless otherwise specified, the reagents or equipment used are commercially available, standard products.

[0030] Conventional adhesive-based interconnection module technology lacks relevant research on improving the power generation capacity of modules by utilizing the properties of the adhesive itself, nor does it have design requirements for the aesthetic appearance of adhesive-based interconnection modules. Conventional technology often focuses on the strength of the adhesion of adhesive units and does not address the problem that the presence of adhesive units (e.g., adhesive points) affects the aesthetic appearance of the photovoltaic module. There is no conventional technology that can make the outlines of adhesive units invisible during visual inspection. The inventors have found that by creatively adjusting the refractive index of the adhesive unit and the sealing layer to satisfy a specific relational equation, and by adjusting the thickness of the sealing layer and the height of the adhesive unit to a specific ratio, the outlines of the adhesive units can be made invisible during visual inspection of the photovoltaic module, while simultaneously further improving the power generation capacity of the photovoltaic module. As shown in Figures 1 and 2, an embodiment of the present invention provides a photovoltaic module 100. The photovoltaic module 100 includes a battery string 110 and a sealing layer 120, the sealing layer 120 being in close contact with the battery string 110 and serving a sealing protection role.

[0031] The battery string 110 includes a plurality of solar cells 111 and a plurality of conductive connecting members 112. The plurality of solar cells 111 are arranged in sequence, and two adjacent solar cells 111 are electrically connected by the conductive connecting members 112 to form the battery string 110. An adhesive unit 113 is further provided between the sealing layer 120 and the battery string 110, and the conductive connecting members 112 are bonded to the solar cells 111 using the adhesive unit 113 (e.g., adhesive points), thereby improving the strength of the connection of the conductive connecting members 112.

[0032] The present invention creatively adjusts the refractive index of the adhesive unit 113 and the sealing layer 120 with respect to light rays, so that the refractive index of both satisfies a specific relational equation, thereby achieving the technical effect of making the outline of the adhesive unit invisible during visual inspection. Based on this, the solar power generation module manufactured according to the present invention can further improve the amount of electricity generated by the solar power generation module.

[0033] As shown in Figures 3 and 4, the refractive index matching of the sealing material has a significant impact on the power and appearance of the module. Therefore, embodiments of the present invention adjust the selection of materials for the sealing layer 120 and the adhesive unit 113 so that the refractive index of the sealing layer 120 and the adhesive unit 113 meets specific requirements. Furthermore, after lamination of the manufactured photovoltaic module, the adhesive unit 113 is hidden within the sealing layer 120 so that the contour of the adhesive unit 113 is not visible on the surface. Specifically, embodiments of the present invention define a characteristic value R that reflects the intensity of reflection when light rays are incident from the sealing layer 120 to the adhesive unit 113, and its formula is given by the following equation (1).

number

number

[0034] H represents the thickness of the sealing layer, which, as shown in Figure 1, is the distance along the direction perpendicular to the battery cell between the first position of the sealing layer closest to the surface of one battery cell and the second position of the sealing layer furthest from the surface of the battery cell. In other words, if sealing layers are provided on both sides of the battery cell, H represents the thickness of the sealing layer on one side. Furthermore, the measurement position of H may be approximately 5 mm from the adhesive unit 113.

[0035] h represents the height of the adhesive unit, which, as shown in Figure 5, is the distance along the perpendicular direction to the battery cell between the first position of the adhesive unit closest to the surface of one battery cell and the second position of the adhesive unit furthest from the surface of the battery cell. In other words, if adhesive units are provided on both sides of the battery cell, h represents the distance that one side of the adhesive unit extends along the perpendicular direction to the battery cell.

[0036] By adjusting the values ​​of H and h, the condition Y ≤ 0.9 can be satisfied, such as Y ≤ 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, etc.

[0037] Furthermore, by adjusting the value of R to 0.014 to 0.118, the matching of the refractive index of the adhesive unit 113 on the surface of the battery cell with the refractive index of the sealing layer 120 is optimized. This reduces the reflection intensity of incident light between the two materials and enables controllability of the propagation direction of incident light in the intersection region of the sealing layer 120, adhesive unit 113, and conductive connecting member 112. This allows more incident light to reach the surface of the solar cell 111, further improving the power generation capacity of the module. Additionally, by optimizing the matching of the height of the adhesive unit 113 on the surface of the solar cell 111 with the thickness of the sealing layer 120, Y ≤ 0.9 is achieved, avoiding the generation of air bubbles between the two materials or within the main structure, further improving the utilization rate of incident light. Due to the significant reduction in reflected light, there is no clear boundary between the adhesive point and the adhesive film, resulting in a visually integrated appearance and improved aesthetics of the module.

[0038] Furthermore, if the characteristic value R < 0.014, when n1 and n2 are sufficiently close and the incident light enters the bonding unit 113 (e.g., the bonding point) from the sealing layer 120, it propagates in an almost straight line, is easily shielded by the solder strip, and is also unfavorable for improving the module's power. If the characteristic value R > 0.118, the contour of the bonding point becomes visible on the module's surface, which is not a desirable choice in terms of both the module's appearance and power.

[0039] In addition, when the characteristic value Y > 0.9, that is, when H is too small or h is too large, or when the thickness H of the sealing layer 120 is too small, the content of the adhesive film is insufficient and the filling is insufficient, and bubbles are likely to occur inside the adhesive film body, which affects the performance and appearance of the module. In particular, when bubbles occur on the surface of the bonding point, the refractive index of the bubbles is close to 1, and the light reflection intensity R between the interface of the bubbles and the bonding point is much larger than 0.118, so some bonding points can be seen on the surface of the module. When the bonding unit 113 (for example, the bonding point) is too large, as shown in FIG. 7, due to the particularity of the printing process, bubbles are easily involved in the bonding point and enter its interior, and bubbles 160 (including bubbles 161 inside the bonding point and bubbles 162 outside the bonding point) are generated. At the same time, because the bonding unit 113 is too large, it is difficult to fill the narrow gap between the solder strip and the inside of the bonding point, and bubbles are also generated. Furthermore, the bonding point can be seen, which is disadvantageous to the performance of the module.

[0040] In a preferred embodiment, by adjusting the values of n1 and n2, the value of R is set to 0.020 to 0.097. By controlling the value of R within the above range, on the premise that the bonding points cannot be seen on the surface of the module, the battery efficiency can be further improved.

[0041] In a preferred embodiment, in order to optimize the compatibility between the adhesive film and the adhesive and improve the utilization rate of the incident light source, the refractive index n1 of the bonding unit 113 with respect to light and the refractive index n2 of the sealing layer 120 with respect to light satisfy n1 < n2. When n1 and n2 satisfy n1 < n2, the sealing layer 120 corresponds to an optically dense medium, and the bonding unit 113 corresponds to an optically sparse medium. When light enters from an optically dense medium to an optically sparse medium, the refracted light deviates from the normal line, as shown in FIG. 5. Under such conditions, more incident light can reach the surface of the battery cell, which is further advantageous for improving the module power.

[0042] Conversely, in the case where n1 > n2, the schematic diagram of ray propagation, as shown in Figure 6, shows that the incident ray is close to the normal, which is likely to cause shielding by the solder strip and is unfavorable for improving the module's power.

[0043] In some embodiments, the refractive index n1 of the adhesive unit 113 with respect to light is 1.35 to 1.60, and may be, for example, 1.35, 1.40, 1.45, 1.50, 1.55, 1.60, etc. The refractive index of the adhesive used to form the adhesive unit 113 with respect to light is approximately the same as the refractive index of the finally formed adhesive unit 113 with respect to light. That is, the refractive index value of the adhesive used to form the adhesive unit 113 also satisfies 1.35 to 1.60. The adhesive used to form the adhesive unit 113 is selected from at least one of silicone-based adhesives, acrylic-based adhesives, and epoxy resin-based adhesives.

[0044] Furthermore, the refractive index n2 of the sealing layer 120 with respect to light is 1.40 to 1.65, and may be, for example, 1.40, 1.45, 1.50, 1.55, 1.60, 1.65, etc. The sealing layer 120 is formed by laminating and crosslinking the sealing film, and the sealing film is selected from at least one of POE sealing film (polyolefin elastomer), EVA sealing film (polyethylene-polyvinyl acetate copolymer), and EPE sealing film (co-extruded product of POE and EVA).

[0045] Furthermore, if the refractive index n1 of the adhesive unit 113 with respect to light is too low or too high (less than 1.35 or greater than 1.65), it will be necessary to modify it by introducing a large amount of a low-refractive-index or high-refractive-index substance, which will significantly affect other properties of the adhesive.

[0046] In some embodiments, the height of the adhesive unit is 50 to 280 μm, specifically 50 μm, 80 μm, 100 μm, 130 μm, 150 μm, 180 μm, 200 μm, 230 μm, 250 μm, 280 μm, etc., and the thickness of the sealing layer is 300 to 400 μm, for example 300 μm, 330 μm, 350 μm, 380 μm, 400 μm, etc.

[0047] In embodiments of the present invention, the refractive index n1 of the adhesive unit 113 and the refractive index n2 of the sealing layer 120 are adjusted to satisfy a specific relationship, and at the same time, the ratio Y of the adhesive unit height to the sealing layer thickness is adjusted to satisfy a specific value, thereby preventing the presence of adhesive points from being detected on the surface of the module. In the actual operation process, it is possible to determine whether adhesive points can be detected by the following method. The module's surface is photographed with a camera, grayscale values ​​are obtained for different regions, and a characteristic value G is calculated. G = |g2 - g1| However, the characteristic value G is a grayscale threshold, where g1 is the grayscale value of the region on the surface of the solar power generation module 100 where no adhesive unit 113 exists (for example, the region on the surface of the battery cell at a position of about 10 mm near the adhesive unit 113), and g2 is the grayscale value of the region on the surface of the solar power generation module 100 where the adhesive unit 113 exists. If G > 20, the adhesive point can be detected, and if G ≤ 20, the adhesive point cannot be detected. The solar power generation module according to the embodiment of the present invention is detected using the above method and satisfies G ≤ 20.

[0048] In some embodiments, the conductive connecting member 112 may be a solder strip, and the material of the solder strip is not limited and may be copper wire, specifically, commercially available copper wire plated with tin-lead solder on its surface can be used.

[0049] In some embodiments, the bonding unit 113 may be a bonding point or line formed by curing the adhesive, or a combination of both, and the curing method may be curing by lamp radiation heating, curing by ultraviolet irradiation, or curing by infrared heating, and the type of adhesive is not limited, and the positions of the bonding points correspond to the positions of the solder strip, and one solder strip is bonded to the solar cell 111 by a plurality of bonding points provided at intervals.

[0050] Referring again to Figures 1, 2, and 4, the multiple solar cells 111 are arranged at intervals, and one side of each solar cell 111 is connected to the back surface of an adjacent solar cell 111 via a conductive connecting member 112, thereby realizing a series connection of the solar cells 111, with adhesive units 113 provided on both sides of the surface of the battery string 110. The conductive connecting member 112 extends from one end in the arrangement direction of the solar cells 111 to the opposite end, and in other directions perpendicular to the arrangement direction, the multiple conductive connecting members 112 are provided at intervals.

[0051] In some types of solar cells, such as back-contact type BC cells, the surface of the battery string 110 has conductive connecting members on only one side, and correspondingly, the surface of the battery string 110 also has adhesive units 113 on only one side.

[0052] In some embodiments, as shown in Figure 1, conductive connecting members 112 and adhesive units 113 are provided on both the front and back surfaces of the solar cell 111, and the sealing layer 120 includes a front film 121 and a back film 122, the front film 121 being in close contact with the front surface of the battery string 110, and the back film 122 being in close contact with the back surface of the battery string 110. When conductive connecting members 112 and adhesive units 113 are provided on both the front and back surfaces of the solar cell 111, the front surface of the battery string 110 is sealed using the front film 121 and the back surface of the battery string 110 is sealed using the back film 122.

[0053] Furthermore, if conductive connecting members 112 and adhesive units 113 are provided on both the front and back surfaces of the solar cell 111, and the sealing layer 120 includes a front film 121 and a back film 122, then at least the ratio R of light reflected when light rays are incident from the front film 121 to the adhesive unit 113 must be 0.014 to 0.118, ensuring that the adhesive points are hidden within the adhesive film when viewed from the module surface.

[0054] In some embodiments, the solar power generation module 100 further includes a front protective substrate 131 and a back protective substrate 132, wherein the front protective substrate 131 is in close contact with the end face of the front film 121 away from the battery string 110, and the back protective substrate 132 is in close contact with the end face of the back film 122 away from the battery string 110. The front protective substrate 131 and the back protective substrate 132 may be transparent substrates and serve to protect the front and back surfaces.

[0055] The material of the surface protection substrate 131 may be glass, which can improve the light transmittance.

[0056] The material of the back protective substrate 132 may be glass, a polymer material, or a mixture of both. If the material of the back protective substrate 132 is a polymer material, it may be at least one of polyethylene terephthalate, polyolefin copolymer, polyamide, polyvinyl fluoride, and polyvinylidene fluoride.

[0057] In some embodiments, the photovoltaic module 100 may further include a frame 150 and busbars 140, the frame 150 serving to protect the perimeter of the module, and adjacent battery strings being connected by the busbars 140 to form a single circuit unit.

[0058] To align and optimize different module manufacturing process windows and module application scenarios, a combination of full coverage (as shown in Figures 1 and 8) and partial coverage (as shown in Figures 9 and 10) is typically formed between the bonding point and the solder strip.

[0059] As shown in Figures 1 and 8, at the location where the adhesive unit 113 is present, the adhesive unit 113 covers the surface of the conductive connecting member 112, and in this case, the adhesive unit 113 completely covers the surface of the conductive connecting member 112. When a process is adopted in which the adhesive is applied and cured after soldering, the adhesive point forms a configuration in which the surface of the conductive connecting member 112 completely covers, as shown in Figure 8.

[0060] In another embodiment, as shown in Figures 9 and 10, at the location where the adhesive unit 113 is present, the adhesive unit 113 is located between the conductive connecting member 112 and the solar cell 111, and the adhesive unit 113 covers a portion of the surface of the conductive connecting member 112, but no covering is formed on the surface of the conductive connecting member 112 away from the solar cell 111. Specifically, when the conductive connecting member 112 is fixed using a process that involves applying and curing an adhesive before soldering, or when the conductive connecting member 112 is fixed using a process that involves applying only an adhesive, the adhesive point forms a configuration that partially covers the conductive connecting member 112, as shown in Figure 10.

[0061] An embodiment of the present invention further provides a method for manufacturing a solar power generation module, the manufacturing method comprising placing a conductive connecting member 112 on at least one surface in the thickness direction of a plurality of solar cells 111, bonding the conductive connecting member 112 and the solar cells 111 with an adhesive unit 113 to form a battery string 110, and then sealing the battery string 110 with a sealing layer 120.

[0062] In the manufacturing process, the refractive index of the sealing layer 120 and the adhesive with respect to light and their own thickness are matched, and a characteristic value R is defined to reflect the intensity of reflection when light rays are incident from the sealing layer 120 to the adhesive unit 113, with the formula being equation (1). A characteristic value Y is defined to explain the relationship of matching the thickness of the sealing layer 120 and the adhesive unit 113, with the formula being equation (2).

number

[0063] Furthermore, by adjusting the refractive index n1 of the sealing layer 120 and the refractive index n2 of the adhesive unit 113 during the manufacturing process, the two can be better matched, making it possible to conceal the contours of the adhesive points on the module surface, which is advantageous for improving the efficiency of the module.

[0064] In some embodiments, multiple solar cells 111 are arranged along a first direction, the finger electrode wires of the solar cells 111 extend along a second direction, the first direction intersects the second direction, and when installing conductive connecting members 112, the conductive connecting members 112 are laid along the first direction. The manufacturing process for the battery string may involve a welding and adhesive application process, a process in which an adhesive is applied and cured before soldering, or a process in which soldering is performed before applying and curing the adhesive.

[0065] Embodiments of the present invention further provide a photovoltaic power generation device, which includes a photovoltaic module 100 provided by an embodiment of the present invention, the photovoltaic module 100 may be M in number, and the M photovoltaic modules 100 are connected in series, where M is an integer of 1 or more, and the specific number may be adjusted according to the requirements of the process.

[0066] In some embodiments, the photovoltaic power generation system may further include an inverter, the output terminal of the photovoltaic power generation system being connected to the input terminal of the inverter and used for photovoltaic power generation.

[0067] The features and performance of the present invention will be described in more detail below with reference to examples.

[0068] Example 1 This embodiment provides a method for manufacturing a solar power generation module, and the specific steps are as follows. (1) Preparation of materials Adhesive preparation: A commercially available silicone-based adhesive (purchased from Delang Juxin Materials Co., Ltd., model number SE-6002) was used. After curing, the refractive index n1 for light at 25±1℃ was 1.42. Preparation of sealing films (front and back): The front sealing film is a commercially available EPE sealing film (purchased from Hangzhou Fostic Applied Materials Co., Ltd., model number EP304), and the back sealing film is a commercially available EVA sealing film (purchased from Hangzhou Fostic Applied Materials Co., Ltd., model number F406P). After lamination, the refractive index n2 for light at 25±1℃ is 1.48 for both. Preparation of solder strips: Use commercially available copper wire plated with tin-lead solder on the surface, with a solder layer thickness of 15 μm and a copper wire diameter of 0.22 mm. Solar cell: A crystalline silicon solar energy battery cell without busbar electrodes (produced by Tongwei Solar Energy (Meishan) Co., Ltd., model number SY11), with a size of 210mm*210mm, a thickness of 130μm, and a half-cut cell size of 210mm*105mm. Flux: Purchased from Shaoxing Tuobang New Energy Co., Ltd., model number FC10V16-6. Busbar: A commercially available flat reflective busbar made of tin-plated copper strip. Surface glass (i.e., surface protective substrate 131): This is a commercially available double-coated glass. The back glass (i.e., the back protective substrate 132) is a commercially available unglazed plated transparent three-hole glass with a hole diameter of 12 mm.

[0069] (2) Manufacturing of battery strings Appropriate amounts of adhesive are sequentially printed on the front and back surfaces of 11 half-cut cells, with a spacing of 10 mm between adjacent adhesive printing positions. Next, solder strips are immersed in flux solution for 1 second, then placed on the corresponding adhesive surfaces. The direction of the solder strip arrangement is parallel to the short side of the half-cut cells. Adjacent battery cells are connected sequentially using solder strips to form the positive and negative electrodes. Finally, the solder strips and the surfaces of the battery cells are alloyed under the lightbox of a welding machine, simultaneously curing the adhesive.

[0070] (3) Sealing The surface glass, surface sealing film, battery string, back film, and back glass are layered in order and arranged. Adjacent battery strings are connected with busbars, and then the adhesive film is melted and crosslinked to obtain sealed battery strings. Finally, the edges are cut and the frame is installed to obtain the finished module.

[0071] As shown in Figure 4, a partial view of the solar power generation module manufactured in Example 1 shows that the contours of the bonding points are not visible during a visual inspection of the solar power generation module.

[0072] Examples 2-6, 11 The only difference from Example 1 is the refractive index n1 of the adhesive and the refractive index n2 of the sealing film. For details, please refer to Table 1.

[0073] Examples 7-10 The only differences from Example 3 are the thickness H of the adhesive film after lamination and the height h after curing with the adhesive; for details, please refer to Table 1.

[0074] Comparative Examples 1-6 The only differences from Example 1 are the refractive index n1 of the adhesive with respect to light, the refractive index n2 of the sealing film with respect to light, the thickness H of the adhesive film after lamination, and the thickness h of the adhesive after curing. For details, please refer to Table 1.

[0075] As shown in Figure 11, a partial view of the solar power generation module manufactured in the comparative example clearly shows the presence of bonding points.

[0076] Test Example 1 The performance of the solar power generation modules manufactured in the examples and comparative examples was tested, and the test results can be found in Table 1.

[0077] Test method: (1) Detection of bonding points: As a method for detecting the contours of bonding points after lamination of the module, first, the surface of the module is photographed with a camera, and grayscale values ​​of different areas are obtained based on a set algorithm program or software such as R3 and Lμmi Tools. Specifically, this is explained based on the following formula. G = |g2 - g1|. However, the characteristic value G is a grayscale threshold, where g1 is the grayscale value of the region on the module surface where no adhesion points exist, and g2 is the grayscale value of the region on the module surface where adhesion points exist. If G > 20, adhesion points can be detected, and if G ≤ 20, adhesion points cannot be detected. (2) Refractive index test: First, a commercially available adhesive or adhesive film is cured or laminated at process temperature, cooled to room temperature (25°C ± 1°C), and then the sample to be tested is obtained. The refractive index of the test sample is then tested at an ambient temperature of 25 ± 1°C using a refractive index testing apparatus (e.g., an Abbe refractometer). (3) Performance detection: Test the amount of power generated using the IEC 61215 standard.

[0078] [Table 1] TIFF2026099721000008.tif65170

[0079] As can be seen from this, if the characteristic value R is outside the range of 0.014 to 0.118 limited in this application, and the characteristic value Y is outside the range of ≤0.9 limited in this application, the amount of power generated by the module decreases, and the presence of adhesion points can be detected on the surface, which is detrimental to improving the aesthetic appearance of the module.

[0080] Comparing Examples 1-6, as R increases, the power increases and then decreases. The preferred examples are Examples 2-4, and the preferred range of R values ​​is 0.020-0.097.

[0081] Comparing Examples 3 and 7-10, when the values ​​of H, h, and Y are within the range of ≤0.9, the value of Y has almost no effect on power, and in all cases, the technical effect of not being able to see the bonding point during visual inspection can be achieved. Comparing Examples 3 and 11, although the characteristic values ​​R and Y are the same, in Example 11 n1 > n2, so the light transmission path approaches the solder strip (Figure 6), causing light shielding and further reducing the power generated by the module. In Example 12, although the value of Y is within the range, the height of the bonding point is too large, so gas is drawn into the adhesive during the printing process, causing bubbles to form inside the bonding point after lamination. The reflectivity at the interface between these bubbles and the bonding point is high, and the bonding point becomes visible during visual inspection.

[0082] In Comparative Example 1, the values ​​of n1 and n2 were close, and the value of R was too small, causing the light rays to be blocked by the solder strip. In Comparative Example 2, the difference between n1 and n2 was large, and the value of R was large, resulting in low power in both Comparative Examples 1 and 2. In Comparative Example 2, R was too large, making the bonding point visible. Similarly, in Comparative Example 3, the value of R was large, and the bonding point could be detected. In Comparative Example 4, the value of Y was large, the height of the bonding point was large, and the thickness of the adhesive film was too small, which easily led to poor filling of the adhesive film. This caused air bubbles to form on the surface of the bonding point, and further increased the reflectivity of the light rays on the surface of the bonding point, making the bonding point visible.

[0083] The foregoing are merely preferred embodiments of the present invention and do not limit it, and those skilled in the art can make various changes and modifications to the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention. [Explanation of symbols]

[0084] 100... Solar power generation modules 110... Battery String 111... Solar cell 112...Conductive connecting member 113... Adhesive Unit 120... Sealing layer 121... Surface film 122...Backside film 131...Surface protection substrate 132...Rear protective circuit board 140...bus bar 150...frame 160...bubbles 161...Air bubbles inside the bonding point 162...Bubble outside the adhesive point.

Claims

1. It is a solar power generation module, The battery string includes multiple solar cells and multiple conductive connecting members, wherein adjacent solar cells are electrically connected to each other by the conductive connecting members, The battery string includes a sealing layer that is in close contact with the battery string, An adhesive unit is further provided between the sealing layer and the battery string, and the adhesive unit adheres the conductive connecting member to the solar cell. The defining formula for the characteristic value R is given by equation (1), The defining formula for characteristic value Y is given by equation (2), [Math 6] A photovoltaic module characterized in that, the value of R is 0.014 to 0.118, n1 represents the refractive index of the adhesive unit with respect to light rays, n2 represents the refractive index of the sealing layer with respect to light rays, the value of Y satisfies Y ≤ 0.9, H represents the thickness of the sealing layer, h represents the height of the adhesive unit, and the height of the adhesive unit is 50 to 280 μm.

2. The photovoltaic power generation module according to claim 1, characterized in that the value of R is 0.020 to 0.

097.

3. The photovoltaic module according to claim 1 or 2, characterized in that the refractive index n1 of the adhesive unit with respect to light and the refractive index n2 of the sealing layer with respect to light satisfy n1 < n2.

4. The adhesive unit is provided on only one side of the surface of the battery string, or the adhesive unit is provided on both sides of the surface of the battery string. The photovoltaic module according to claim 1 or 2, characterized in that the adhesive unit is formed by curing an adhesive.

5. The refractive index n1 of the adhesive unit with respect to light is 1.35 to 1.

60. The photovoltaic module according to claim 4, characterized in that the adhesive used to form the adhesive unit is selected from at least one of a silicone-based adhesive, an acrylic-based adhesive, and an epoxy resin-based adhesive.

6. The refractive index n2 of the sealing layer with respect to light is 1.40 to 1.65, and the thickness of the sealing layer is 300 to 400 μm. The photovoltaic module according to claim 3, characterized in that the sealing layer is formed by laminating and crosslinking a sealing film selected from at least one of POE sealing film, EVA sealing film, and EPE sealing film.

7. In the selected embodiment, the surface of the module is photographed with a camera, grayscale values ​​of different regions are obtained, and characteristic values ​​G are calculated. G = |g² - g1|, However, characteristic value G is a grayscale threshold, where g1 is the grayscale value of the region on the surface of the solar power generation module where no adhesive units exist, and g2 is the grayscale value of the region on the surface of the solar power generation module where adhesive units exist. The photovoltaic power generation module according to claim 1, characterized in that the value of G satisfies G ≤ 20.

8. The photovoltaic power generation module according to claim 1, characterized in that, at the location where the adhesive unit is present, the adhesive unit covers the surface of the conductive connecting member.

9. The photovoltaic module according to claim 1, characterized in that, at the location where the adhesive unit exists, the adhesive unit is located between the conductive connecting member and the solar cell, and the adhesive unit covers a portion of the surface of the conductive connecting member.

10. The conductive connecting member and the adhesive unit are provided on both the front and back surfaces of the solar cell, and the sealing layer includes a front film and a back film, the front film is in close contact with the surface of the battery string, and the back film is in close contact with the back surface of the battery string. At a minimum, the characteristic value R is 0.014 to 0.118, and the ratio Y of the height of the adhesive unit to the thickness of the surface film is Y ≤ 0.9, The photovoltaic module according to claim 1, characterized in that the conductive connecting member is a solder strip.

11. The photovoltaic module according to claim 10, characterized in that the plurality of solar cells are arranged at intervals, and one side of each solar cell is connected to the back surface of an adjacent solar cell via the conductive connecting member.

12. The photovoltaic power generation module according to claim 10, further comprising a front protective substrate and a back protective substrate, wherein the front protective substrate is in close contact with the end face of the front film away from the battery string, and the back protective substrate is in close contact with the end face of the back film away from the battery string.

13. The material of the surface protection substrate is glass. The photovoltaic module according to claim 12, characterized in that the material of the back surface protective substrate is selected from at least one of glass and a polymer material, wherein the polymer material includes polyethylene terephthalate, polyolefin copolymer, polyamide, polyvinyl fluoride and polyvinylidene fluoride.

14. A method for manufacturing a solar power generation module, This includes arranging a conductive connecting member on at least one surface in the thickness direction of multiple solar cells, bonding the conductive connecting member to the solar cells with an adhesive unit to form a battery string, and sealing the battery string with a sealing layer. The defining formula for the characteristic value R is given by equation (1), The defining formula for characteristic value Y is given by equation (2), [Number 7] A method for manufacturing a photovoltaic module, characterized in that n1 represents the refractive index of the adhesive unit with respect to light rays, n2 represents the refractive index of the sealing layer with respect to light rays, and the value of R is set to 0.014 to 0.118 by adjusting n1 and n2, H represents the thickness of the sealing layer, h represents the height of the adhesive unit, and Y ≤ 0.9 is set by adjusting H and h.

15. Specifically, forming a battery string involves placing a conductive connecting member on at least one surface in the thickness direction of multiple solar cells, and bonding the conductive connecting member to the solar cells using an adhesive unit. Multiple solar cells are arranged along a first direction, the finger electrode wires of the solar cells extend along a second direction, the first direction and the second direction intersect, and when installing the conductive connecting member, the conductive connecting member is laid along the first direction. The battery string is manufactured using a process in which an adhesive is applied, cured, and then soldered. Alternatively, the method for manufacturing a solar power generation module according to claim 14, characterized in that the battery string is manufactured by a process of applying an adhesive after soldering and then curing it.

16. The method for manufacturing a photovoltaic power generation module according to claim 14, characterized in that the value of R is 0.020 to 0.

097.

17. The method for manufacturing a photovoltaic module according to claim 14 or 16, characterized in that the refractive index n1 of the adhesive unit with respect to light and the refractive index n2 of the sealing layer with respect to light satisfy n1 < n2.

18. A solar power generation device, The photovoltaic power generation module is described in claim 1 or 2, or a photovoltaic power generation module manufactured by the method for manufacturing a photovoltaic power generation module described in any one of claims 14 to 16. The photovoltaic power generation device is characterized in that the photovoltaic power generation modules number M, and the M photovoltaic power generation modules are connected in series, and M is an integer of 1 or more.

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