Solar cell, manufacturing method thereof and photovoltaic module

Abstract

The invention provides a solar cell, a manufacturing method thereof and a photovoltaic module, and relates to the technical field of solar cells. Insulation points are formed at the positions where auxiliary grid lines intersect with main grid lines opposite in polarity, and the step of forming the insulation points comprises the steps that a first insulation layer is printed and pre-cured; a second insulating layer is printed on the first insulating layer and cured, and the width of the second insulating layer in the second direction is smaller than the width of the first insulating layer in the second direction and larger than or equal to the width of the auxiliary grid line in the second direction. The insulation points are formed through step-by-step printing, the insulation points formed at the positions where the auxiliary grid lines intersect with the main grid lines opposite in polarity comprise the first insulation layers and the second insulation layers which are different in width, the step height of the main grid lines at the insulation points is reduced on the premise that the reliability of the insulation slurry is guaranteed, and therefore the resistance of the main grid lines is reduced, and the reliability of the device is improved. And the electrical performance of the solar cell is improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and particularly to a solar cell, a manufacturing method thereof, and a photovoltaic module. Background Art

[0002] Solar cells have the characteristics of being clean and environmentally friendly, and thus are widely used. In back contact (BC) solar cells, all the grid lines are located on the back surface (i.e., the backlight surface) of the cell, and there are no grid lines on the front surface (i.e., the light-facing surface) of the cell. Therefore, BC solar cells are highly sought after by the market for their characteristics of no grid line occlusion on the front surface, increased light-receiving area, and high cell efficiency.

[0003] BC solar cells include IBC (Interdigitated back contact), TBC (Tunneling oxide passivated contact Back Contact), HBC (Heterojunction Back Contact) and other solar cells. The grid lines of BC solar cells mainly consist of busbars (BB) and finger grid lines (also known as fine grid lines). Among them, the busbars mainly play the role of collecting the current of the finger grid lines and connecting them in series, and the finger grid lines are used to collect photo-generated carriers.

[0004] The P region and N region on the back surface of BC solar cells usually adopt a finger-crossed shape. When connecting the busbars to the finger grid lines, the P-region finger grid lines and N-region finger grid lines are isolated by insulating glue, which can achieve greater utilization of the P region and N region. However, the resistance of the busbars formed by the current metallization process is relatively large, which reduces the electrical performance of the solar cells. Summary of the Invention

[0005] In view of this, the present application provides a solar cell, a manufacturing method thereof, and a photovoltaic module, which reduce the resistance of the busbars and improve the electrical performance of the solar cells.

[0006] In a first aspect, the present application provides a manufacturing method of a solar cell, including:

[0007] Providing a solar cell intermediate;

[0008] Forming finger grid lines on the surface of the solar cell intermediate, the finger grid lines extending along a first direction, the finger grid lines including positive electrode finger grid lines and negative electrode finger grid lines, and the positive electrode finger grid lines and the negative electrode finger grid lines being alternately arranged along a second direction, the second direction intersecting the first direction;

[0009] An insulating point is formed at the position where the auxiliary gate line intersects with the main gate line having the opposite polarity. The forming of the insulating point includes: printing a first insulating layer and pre-curing it; printing a second insulating layer on the first insulating layer and curing it. The width of the second insulating layer in the second direction is less than the width of the first insulating layer in the second direction and greater than or equal to the width of the auxiliary gate line in the second direction.

[0010] A main gate line is formed on the surface of the solar cell intermediate body. The main gate line extends along the second direction and includes a positive main gate line and a negative main gate line.

[0011] In a possible implementation, the thickness of the first insulating layer is less than or equal to 20 μm, and the thickness of the second insulating layer is less than or equal to 20 μm.

[0012] In a possible implementation, the sum of the thicknesses of the first insulating layer and the second insulating layer is greater than or equal to 30 μm.

[0013] In a possible implementation, the width of the first insulating layer is 50%-80% of the auxiliary gate line pitch.

[0014] In a possible implementation, the width of the second insulating layer is 30%-50% of the auxiliary gate line pitch.

[0015] In a possible implementation, the temperature of the pre-curing is 120°C - 180°C, and the time is 5 min - 20 min.

[0016] In a possible implementation, the temperature of the curing is 150°C - 200°C, and the time is 5 min - 20 min.

[0017] In a second aspect, the present application provides a solar cell, including:

[0018] Auxiliary gate lines extending along a first direction. The auxiliary gate lines include a positive auxiliary gate line and a negative auxiliary gate line. The positive auxiliary gate line and the negative auxiliary gate line are alternately arranged along a second direction, and the second direction intersects with the first direction;

[0019] Main gate lines extending along the second direction. The main gate lines include a positive main gate line and a negative main gate line;

[0020] Insulating points located between the auxiliary gate lines and the main gate lines having the opposite polarity. The insulating points include a first insulating layer and a second insulating layer. The width of the second insulating layer in the second direction is less than the width of the first insulating layer in the second direction and greater than or equal to the width of the auxiliary gate line in the second direction.

[0021] In a possible implementation, the thickness of the first insulating layer is less than or equal to 20 μm, and the thickness of the second insulating layer is less than or equal to 20 μm.

[0022] In a possible implementation, the sum of the thicknesses of the first insulating layer and the second insulating layer is greater than or equal to 30 μm.

[0023] In a possible implementation, the width of the first insulating layer is 50%-80% of the sub-grid line pitch.

[0024] In a possible implementation, the width of the second insulating layer is 30%-50% of the sub-grid line pitch.

[0025] In a third aspect, the present application provides a photovoltaic module, including a plurality of solar cell strings, and the solar cell strings are composed of the solar cells described in the second aspect.

[0026] Compared with the prior art, the present application has the following advantages:

[0027] In the present application, an insulating point is formed at the intersection of the sub-grid line and the main grid line with opposite polarities. The formation of the insulating point includes: printing a first insulating layer and pre-curing; printing a second insulating layer on the first insulating layer and curing. The width of the second insulating layer in the second direction is less than the width of the first insulating layer in the second direction and greater than or equal to the width of the sub-grid line in the second direction. The present application forms an insulating point by step-by-step printing. The insulating point formed at the intersection of the sub-grid line and the main grid line with opposite polarities includes a first insulating layer and a second insulating layer with different widths. On the premise of ensuring the reliability of the insulating paste, the step height of the main grid line at the insulating point is reduced, thereby reducing the main grid line resistance and improving the electrical performance of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are provided to further understand the present application. They are incorporated into and constitute a part of this application. The accompanying drawings illustrate embodiments of the present application and, together with this specification, serve to explain the principles of the present application. In the accompanying drawings:

[0029] Figure 1 is a partial cross-sectional schematic diagram of a solar cell provided by an embodiment of the present application;

[0030] Figure 2 is a schematic flow chart of a manufacturing method of a solar cell provided by an embodiment of the present application;

[0031] Figure 3 is a schematic structural diagram of a sub-grid line provided by an embodiment of the present application;

[0032] Figure 4It is a schematic structural diagram of a first insulating layer provided by an embodiment of the present application;

[0033] Figure 5 It is a schematic structural diagram of a second insulating layer provided by an embodiment of the present application;

[0034] Figure 6 It is a schematic side view of an insulating point provided by an embodiment of the present application;

[0035] Figure 7 It is a schematic partial top view of a solar cell provided by an embodiment of the present application. Detailed implementation manners

[0036] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present application. For those of ordinary skill in the art, without creative efforts, the present application can also be applied to other similar scenarios based on these drawings. Unless obvious from the language context or otherwise stated, the same reference numerals in the figures represent the same structure or operation.

[0037] As shown in the present application, unless the context clearly indicates an exceptional situation, words such as "a", "an", "one" and / or "the" do not specifically refer to the singular, but may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of the clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0038] Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and values set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that for the sake of convenience of description, the dimensions of the various parts shown in the accompanying drawings are not drawn in actual proportional relationships. Technologies, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods and devices should be regarded as part of the specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0039] In addition, although the terms used in this application are selected from well-known and commonly used terms, some of the terms mentioned in the specification of this application may be chosen by the applicant according to his or her judgment, and their detailed meanings are described in the relevant parts of the description herein. In addition, it is required to understand this application not only through the actual terms used, but also through the meanings implied by each term.

[0040] It should be understood that when a component is referred to as "on another component", "connected to another component", "coupled to another component", or "in contact with another component", it can be directly on, connected to, or coupled to, or in contact with the other component, or there may be an intervening component. In contrast, when a component is referred to as "directly on another component", "directly connected to", "directly coupled to", or "directly in contact with" another component, there is no intervening component.

[0041] Flowcharts are used in this application to illustrate the operations performed by the methods according to the embodiments of this application. It should be understood that the operations before or below do not necessarily need to be executed precisely in order. Instead, they can be executed in reverse order or simultaneously. Also, other operations can be added to these processes, or one or more steps can be removed from these processes.

[0042] Figure 1 It is a partial cross-sectional schematic diagram of a solar cell provided by an embodiment of this application. As Figure 1 shown, the solar cell 100 includes a semiconductor substrate 101, and the semiconductor substrate 101 has a front surface (the upper surface in the figure) and a back surface (the lower surface in the figure) in its thickness direction. When the solar cell is operating, the front surface faces the sun. Multiple solar cells can form a solar cell string, and multiple solar cell strings can further form a photovoltaic module.

[0043] The semiconductor substrate 101 includes a light absorption layer and several layers with certain functions formed on the surface (front and / or back) of the light absorption layer, such as an electron transport layer, a hole transport layer, a passivation layer, an antireflection layer, etc. The light absorption layer is used to absorb light energy and convert it into electrical energy, such as an amorphous silicon light absorption layer, a polycrystalline silicon light absorption layer, a perovskite light absorption layer, etc. In some embodiments, the light absorption layer is a silicon wafer, which can be a single-crystalline silicon wafer or a polycrystalline silicon wafer, and can be a P-type silicon wafer or an N-type silicon wafer. For example, by adding a pentavalent element such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As) to silicon, there are extra free electrons in the silicon, thus obtaining an N-type silicon wafer. By adding a trivalent element such as boron (B), aluminum (Al), gallium (Ga), or indium (In) to silicon, there are "holes" (places lacking electrons) in the silicon, and these holes can accept electrons, thus obtaining a P-type silicon wafer. For example, when the silicon wafer is a P-type silicon wafer, the type of the doping element inside it is P-type. Another example, when the silicon wafer is an N-type silicon wafer, the type of the doping element inside it is N-type.

[0044] An electrode for collecting and transporting charges is formed on the surface of the semiconductor substrate 101. In an exemplary embodiment, as Figure 1 shown, the back surface of the semiconductor substrate 101 has an electrode 102, that is, the solar cell 100 is a BC-type solar cell. The electrode 102 includes a positive electrode 1021 and a negative electrode 1022, and the positive electrode 1021 and the negative electrode 1022 are alternately arranged on the surface of the semiconductor substrate 101. It should be noted that in some other embodiments, the front surface of the semiconductor substrate 101 can also have an electrode. For example, both the front surface and the back surface of the semiconductor substrate 101 have electrodes, and the polarities of the electrodes on the front surface of the semiconductor substrate 101 and the electrodes on the back surface of the semiconductor substrate 101 are opposite.

[0045] The electrode 102 is formed by grid lines and includes a main grid electrode and a secondary grid electrode. Currently, the metallization process steps of BC-type solar cells are as follows: 1) Print the secondary grid lines and cure; 2) Print the insulating glue and cure; 3) Print the main grid lines and cure. The isolation between the secondary grid lines and the main grid lines with different polarities in BC-type solar cells is achieved by printing insulating glue. Due to the requirements of insulation and reliability of the insulating glue, the thickness of the insulating glue is relatively high, and there is a certain height difference on the surface of the semiconductor substrate 101 after the insulating glue is cured. The main components of the low-temperature paste for the main grid lines include silver powder, solvent, additives, and stabilizers. Among them, the solvent, additives, and stabilizers are all organic systems. During the curing process, the low-temperature silver paste flows and redistributes again. The step at the connection between the main grid line and the insulating glue is too high, which affects the distribution of the main grid line paste at the step, thereby affecting the resistance of the main grid line and ultimately the conversion efficiency of the solar cell. Specifically, due to the existence of the height difference when printing the main grid lines, it is not conducive to the flow of the paste, resulting in broken grids or poor connections in the main grid lines after curing, making the resistance of the main grid line too large and ultimately reducing the electrical performance of the solar cell. Although reducing the thickness of the insulating glue can reduce the step height, however, reducing the thickness of the insulating glue poses a risk of failure at the insulating paste, and there is a certain risk to the reliability of the battery.

[0046] The embodiment of the present application adopts a scheme of printing the insulating glue step by step. First, print a thin-layer large-area insulating glue, and then print a thin-layer small-area insulating glue to reduce the step height at the insulating point of the main grid line, thereby reducing the resistance of the main grid line and improving the electrical performance of the solar cell.

[0047] Figure 2 It is a schematic flow diagram of a manufacturing method of a solar cell provided by an embodiment of the present application.

[0048] As Figure 2 shown, the manufacturing method of the solar cell includes the following steps:

[0049] Step S210: Provide a solar cell intermediate.

[0050] The solar cell intermediate can be Figure 1 the semiconductor substrate 101 shown. In some embodiments, the solar cell intermediate can be obtained by performing certain pretreatment on the silicon wafer. The pretreatment includes but is not limited to cleaning, polishing, or forming a specific layer on the silicon wafer surface, such as a silicon dioxide layer, an intrinsic amorphous silicon layer, etc.

[0051] Step S220: Form secondary grid lines on the surface of the solar cell intermediate.

[0052] Please refer to Figure 3, the substrate 301 may be the solar cell intermediate provided in step S210. A plurality of sub-grid lines 302 are formed on the surface of the substrate 301, and the sub-grid lines 302 can be formed by means such as screen printing. The sub-grid lines 302 extend along the first direction A, and the sub-grid lines 302 include a positive sub-grid line 3021 and a negative sub-grid line 3022. The positive sub-grid line 3021 and the negative sub-grid line 3022 are alternately arranged along the second direction B, where the second direction B intersects the first direction A. In an exemplary embodiment, the second direction B is perpendicular to the first direction A, such as Figure 3 shown.

[0053] The center distance d between two adjacent sub-grid lines 302 is called the sub-grid line pitch. In some embodiments, the width of the sub-grid lines 302 is 20μm - 300μm, for example, it can be 20μm, 30μm, 50μm, 70μm, 90μm, 100μm, 130μm, 150μm, 180μm, 200μm, 220μm, 250μm, 270μm, 290μm, 300μm, and any range between these values. The sub-grid line pitch is 0.3mm - 3mm, for example, it can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.9mm, 1mm, 1.2mm, 1.5mm, 1.6mm, 1.8mm, 2mm, 2.3mm, 2.5mm, 2.7mm, 2.8mm, 2.9mm, 3mm, and any range between these values.

[0054] Step S230: Form insulating points at the positions where the sub-grid lines intersect the main grid lines with opposite polarities.

[0055] The main grid lines are used to collect the current of the sub-grid lines. The sub-grid lines with the same polarity are connected to the main grid lines, and the sub-grid lines with opposite polarities are insulated from the main grid lines. That is, the positive sub-grid lines are connected to the positive main grid lines with the same polarity, and the positive sub-grid lines are insulated from the negative main grid lines with opposite polarities. The negative sub-grid lines are connected to the negative main grid lines with the same polarity, and the negative sub-grid lines are insulated from the positive main grid lines with opposite polarities. In the embodiment of the present application, insulating points are formed at the positions where the sub-grid lines intersect the main grid lines with opposite polarities to achieve the insulation between the sub-grid lines with opposite polarities and the main grid lines.

[0056] Please refer to Figures 4 - 6, forming the insulating point 303 includes: printing a first insulating layer 3031 and pre-curing it; printing a second insulating layer 3032 on the first insulating layer 3031 and curing it, where the width a1 of the first insulating layer in the second direction B is greater than or equal to the width of the sub-grid line 302 in the second direction B, and the width a2 of the second insulating layer 3032 in the second direction B is less than the width a1 of the first insulating layer 3031 in the second direction B. Specifically, the pre-curing temperature can be lower than the curing temperature, and it is only necessary to cure the insulating paste for printing the first insulating layer 3031 so that it does not flow.

[0057] When forming the insulating point 303 in the embodiment of the present application, the insulating glue is printed in a step-by-step printing method. First, the first insulating layer 3031 with a larger width is printed, and then the second insulating layer 3032 with a smaller width is printed. On the premise of ensuring the reliability of the insulating paste, the step height of the surface of the insulating point of the solar cell is improved, the connection between the insulating point and the main grid line is optimized, the influence of the insulating point on the low-temperature silver paste during the curing of the low-temperature silver paste is reduced, thereby reducing the main grid line resistance and improving the electrical performance of the solar cell. It can be understood that the step-by-step printing steps can include two steps or three steps or more steps. First, an insulating layer with a larger width is printed, and then an insulating layer with a smaller width is printed. The width of the insulating layer can gradually decrease, and it is cured when printing the insulating paste in the last step, and pre-cured when printing the insulating paste in other steps. That is, the insulating point 303 can include two insulating layers or three insulating layers or more insulating layers with different widths. For example, the step-by-step printing steps include three steps. In the first step, an insulating layer with the largest width is printed and pre-cured; in the second step, an insulating layer with a smaller width is printed and pre-cured; in the third step, an insulating layer with the smallest width is printed and cured. It should be noted that the width mentioned here refers to the width of the insulating layer in the second direction B, that is, the width of the insulating layer in the extending direction of the main grid line.

[0058] In some embodiments, the width a1 of the first insulating layer 3031 is 50%-80% of the sub-grid line pitch. For example, it can be 50%, 51%, 52%, 55%, 60%, 65%, 70%, 75%, 78%, 79%, 80%, and any range between these values, which can ensure the insulation effectiveness between the main grid line and the sub-grid line and avoid affecting the conduction of adjacent sub-grid lines. The width a2 of the second insulating layer 3032 is 30%-50% of the sub-grid line pitch. For example, it can be 30%, 31%, 32%, 35%, 38%, 40%, 43%, 45%, 47%, 49%, 50%, and any range between these values, so that the width of the overlapping area between the second insulating layer 3032 and the first insulating layer 3031 ensures the isolation between the sub-grid line and the main grid line.

[0059] In some embodiments, the thickness h1 of the first insulating layer 3031 is less than or equal to 20 μm, for example, it can be 20 μm, 19 μm, 18 μm, 17 μm, 16 μm, 15 μm, 14 μm, 13 μm, 12 μm, 11 μm, 10 μm, etc. The thickness h2 of the second insulating layer 3032 is less than or equal to 20 μm, for example, it can be 20 μm, 19 μm, 18 μm, 17 μm, 16 μm, 15 μm, 14 μm, 13 μm, 12 μm, 11 μm, 10 μm, etc. This further reduces the step height of the main grid line at the insulating point and avoids the occurrence of broken grid or poor connection of the main grid line. In some embodiments, the sum of the thicknesses of the first insulating layer 3031 and the second insulating layer 3032 is greater than or equal to 30 μm, for example, it can be 30 μm, 31 μm, 32 μm, 33 μm, 34 μm, 35 μm, 36 μm, 37 μm, 38 μm, 39 μm, 40 μm, etc., to avoid insulation failure caused by too low thickness of the insulating point 303 and the risk of battery reliability.

[0060] In some embodiments, the pre-curing temperature of the first insulating layer 3031 is 120°C - 180°C and the time is 5 min - 20 min, so that the insulating paste is cured and does not flow, serving as the bottom layer material. The curing temperature of the second insulating layer 3032 is 150°C - 200°C and the time is 5 min - 20 min, so that the insulating paste is completely cured to form the insulating point 303.

[0061] In the embodiments of the present application, by the method of stepwise printing and drying the insulating glue multiple times, on the basis of ensuring the thickness of the insulating point, the volatilization amount of the organic matter inside the insulating glue is reduced, the pore amount of the insulating glue is reduced, and the insulation reliability of the insulating glue is improved.

[0062] Step S240: Form a main grid line on the surface of the solar cell intermediate.

[0063] Please refer to Figure 7 , several main grid lines 304 are formed on the surface of the substrate 301, and the main grid lines 304 can be formed by means such as screen printing. In some embodiments, the main grid lines 304 are printed on the surface of the substrate 301 and cured, and the curing temperature is 180°C - 220°C and the time is 5 min - 20 min. The sub-grid lines 302 and the main grid lines 304 constitute the electrodes, and the electrodes formed in the above embodiments can be used as the electrodes of a solar cell having a positive electrode and a negative electrode on the same surface, such as BC type solar cells such as IBC, TBC, and HBC.

[0064] The main grid line 304 extends along the second direction B, and the main grid line 304 includes a positive main grid line 3041 and a negative main grid line 3042. In some embodiments, the positive main grid line 3041 and the negative main grid line 3042 are alternately arranged along the first direction A.

[0065] The insulating point 303 is located between the sub-grid line 302 and the main grid line 304 with opposite polarities. The positive main grid line 3041 is connected to the positive sub-grid line 3021 with the same polarity, and is isolated from the negative sub-grid line 3022 with opposite polarity by the insulating point 303. The negative main grid line 3042 is connected to the negative sub-grid line 3022 with the same polarity, and is isolated from the positive sub-grid line 3021 with opposite polarity by the insulating point 303.

[0066] In a specific embodiment, the pre-curing temperature of the first insulating layer 3031 is 150 °C and the time is 15 min. The thickness of the first insulating layer 3031 is approximately 20 μm, and the width is approximately 600 μm (the sub-grid line pitch is 1000 μm). The total thickness of the second insulating layer 3032 and the first insulating layer 3031 after superposition is approximately 35 μm, and the width of the second insulating layer 3032 is approximately 300 μm. The drying temperature when forming the main grid line is 200 °C and the time is 15 min. Compared with the solar cell in which the insulating point is formed by one-step printing, the sheet resistance of the main grid line in the solar cell of this specific embodiment can be reduced from 3 mΩ·cm to 1.5 mΩ·cm.

[0067] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only an example and does not constitute a limitation to this application. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are proposed in this application, so such modifications, improvements, and corrections still fall within the spirit and scope of the exemplary embodiments of this application.

[0068] At the same time, specific terms are used in this application to describe the embodiments of this application. Such as "one embodiment", "an embodiment", and / or "some embodiments" mean a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that the "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more at different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application can be appropriately combined.

[0069] Similarly, it should be noted that, in order to simplify the expression of this application disclosure and thus help the understanding of one or more inventive embodiments, in the foregoing description of the embodiments of this application, sometimes multiple features are merged into one embodiment, drawing, or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned. In fact, the features of the embodiment are less than all the features of the single embodiment disclosed above.

[0070] In some embodiments, numbers are used to describe components and the quantity of attributes. It should be understood that such numbers used in the description of embodiments are, in some examples, modified by the modifiers "about", "approximately" or "substantially". Unless otherwise stated, "about", "approximately" or "substantially" indicate that the said numbers allow a variation of ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification are approximate values, which may vary according to the characteristics required by individual embodiments. In some embodiments, the numerical parameters should consider the specified significant digits and adopt the method of retaining the general number of digits. Although the numerical ranges and parameters used in some embodiments of the present application to confirm the breadth of their scope are approximate values, in specific embodiments, such numerical settings are made as precise as possible within the feasible range.

[0071] Although the present application has been described with reference to the current specific embodiments, those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions can be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the scope of the spirit of the present application, they will fall within the scope of the present application.

Claims

1. A method for manufacturing a solar cell, characterized in that: include: Providing solar cell intermediates; A secondary grid line is formed on the surface of the solar cell intermediate body, the secondary grid line extends along a first direction, the secondary grid line includes a positive secondary grid line and a negative secondary grid line, the positive secondary grid line and the negative secondary grid line are alternately arranged along a second direction, and the second direction intersects the first direction; An insulating point is formed at a position where the secondary gate line intersects with a main gate line with opposite polarity, wherein the forming of the insulating point comprises: printing a first insulating layer and pre-curing; printing a second insulating layer on the first insulating layer and curing, wherein the width of the first insulating layer in the second direction is greater than or equal to the width of the secondary gate line in the second direction, and the width of the second insulating layer in the second direction is less than the width of the first insulating layer in the second direction; A main grid line is formed on the surface of the solar cell intermediate body, the main grid line extends along the second direction, and the main grid line includes a positive main grid line and a negative main grid line.

2. The manufacturing method according to claim 1, characterized in that The thickness of the first insulating layer is less than or equal to 20 μm, and the thickness of the second insulating layer is less than or equal to 20 μm.

3. The manufacturing method according to claim 1 or 2, characterized in that: The sum of the thickness of the first insulating layer and the second insulating layer is greater than or equal to 30 μm.

4. The manufacturing method according to claim 1, characterized in that: The width of the first insulating layer is 50%-80% of the spacing between the auxiliary gate lines.

5. The manufacturing method according to claim 1 or 4, characterized in that: The width of the second insulating layer is 30%-50% of the spacing between the auxiliary gate lines.

6. The manufacturing method according to claim 1, characterized in that: The pre-curing temperature is 120° C.-180° C., and the pre-curing time is 5 min-20 min.

7. The manufacturing method according to claim 1 or 6, characterized in that: The curing temperature is 150° C.-200° C., and the curing time is 5 min-20 min.

8. A solar cell, characterized in that: include: Auxiliary grid lines extending along a first direction, the auxiliary grid lines comprising positive auxiliary grid lines and negative auxiliary grid lines, the positive auxiliary grid lines and the negative auxiliary grid lines are alternately arranged along a second direction, and the second direction intersects the first direction; Main grid lines extending along the second direction, the main grid lines comprising positive main grid lines and negative main grid lines; An insulating point is located between the secondary gate line and the main gate line with opposite polarity, and the insulating point includes a first insulating layer and a second insulating layer, wherein the width of the first insulating layer in the second direction is greater than or equal to the width of the secondary gate line in the second direction, and the width of the second insulating layer in the second direction is less than the width of the first insulating layer in the second direction.

9. The solar cell according to claim 8, characterized in that The thickness of the first insulating layer is less than or equal to 20 μm, and the thickness of the second insulating layer is less than or equal to 20 μm.

10. The solar cell according to claim 8 or 9, characterized in that: The sum of the thickness of the first insulating layer and the second insulating layer is greater than or equal to 30 μm.

11. The solar cell according to claim 8, wherein: The width of the first insulating layer is 50%-80% of the spacing between the auxiliary gate lines.

12. The solar cell according to claim 8 or 11, characterized in that: The width of the second insulating layer is 30%-50% of the spacing between the auxiliary gate lines.

13. A photovoltaic module, characterized in that: The invention comprises a plurality of solar cell strings, wherein the solar cell strings are composed of the solar cells according to any one of claims 8 to 12.

Images