A gate line plate for a silicon surface photovoltaic cell and a forming process thereof

Abstract

The application provides a grid circuit board for a silicon surface photovoltaic cell and a forming process thereof, comprising a metal wire and a substrate, the metal wire is provided with a composite coating layer on the periphery, the composite coating layer is a composite material layer of resin and glass powder; the upper surface of the substrate is provided with a silicon nitride passivation layer; the metal wire is fixed and attached to the substrate through the composite coating layer, after sintering, the composite coating layer is melted, the silicon nitride passivation layer is dissolved in the composite coating layer, so that an electrically conductive path is formed between the metal wire and the substrate. The grid circuit board for the silicon surface photovoltaic cell can simplify the manufacturing process of the photovoltaic grid, reduce the use of silver paste, and obtain a photovoltaic grid with smaller light grid width and better conductive performance.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic gate technology, and more specifically to a gate circuit board for silicon surface photovoltaic cells and its molding process. Background Technology

[0002] Faced with increasingly severe global challenges such as energy resource constraints and rising global temperatures, China is promoting a comprehensive green transformation of its economic and social development, striving to advance its clean and low-carbon energy development. Photovoltaic power generation has replaced hydropower as my country's second-largest power source and is becoming one of the important energy sources for future sustainable development. To further expand the scale of the photovoltaic industry, deepen its application across various sectors, reduce manufacturing costs, and improve photoelectric conversion efficiency, it is imperative to proceed. Silicon-based surface photovoltaic cells have wide applications in the photovoltaic industry, including TOPCon cells, PERC cells, and IBC cells.

[0003] Through-oxide passivated contact solar cells have a core structure consisting of an ultrathin silicon oxide layer and a heavily doped polycrystalline silicon layer on the back of the cell, which together form the passivation contact structure. Silicon-based surface photovoltaic cells offer high overall cost-effectiveness and are relatively easy to implement under current technological and economic conditions, making them a key technology for next-generation photovoltaic cells.

[0004] Currently, the conductive grid of photovoltaic (PV) gates in silicon-based surface photovoltaic (SPV) cells is generally fabricated using screen printing. However, the screen printing process requires a large amount of silver paste, leading to high production costs. Furthermore, screen printing is not only complex but also presents a series of problems, including wider grid widths and poor conductivity. Summary of the Invention

[0005] This invention provides a gate circuit board for silicon surface photovoltaic cells, aiming to solve a series of problems such as complicated manufacturing process, wide grating width, and poor conductivity of existing gate circuit boards.

[0006] In a first aspect, embodiments of the present invention provide a gate circuit board for a silicon surface photovoltaic cell, comprising: a metal wire and a substrate, wherein the metal wire is surrounded by a composite coating layer, the composite coating layer being a composite material layer of resin and glass powder; a silicon nitride passivation layer is provided on the upper surface of the substrate; the metal wire is cured and bonded to the substrate through the composite coating layer, and after sintering, the composite coating layer melts, and the silicon nitride passivation layer dissolves in the composite coating layer, thereby forming a conductive path between the metal wire and the substrate.

[0007] Preferably, the resin in the composite coating layer is made of polyethylene, epoxy resin, polyethylene terephthalate, polymethyl methacrylate, or other resins with a decomposition temperature below 500°C.

[0008] Preferably, the glass powder in the composite coating layer is glass powder or other glass powder with a particle size of 0.01-10 micrometers.

[0009] Preferably, the metal wire is a copper wire, silver wire, gold wire, iron wire, aluminum wire, tungsten wire, alloy, or a conductive metal wire with a metal coating on its surface.

[0010] Secondly, embodiments of the present invention provide a molding process for a gate circuit board for a silicon surface photovoltaic cell, used to prepare the gate circuit board for a silicon surface photovoltaic cell as described above, the molding process comprising the following steps:

[0011] S1. The glass powder is uniformly dispersed in epoxy resin to form a composite coating;

[0012] S2. Immerse the metal wire in the composite coating and coat the surface of the metal wire with a layer of the composite coating.

[0013] S3. A silicon nitride passivation layer is deposited on the substrate to obtain a substrate with a passivated surface, and a metal wire with the composite coating on its surface is attached to the substrate so that the composite coating is in contact with the silicon nitride passivation layer.

[0014] S4. The composite coating and the silicon nitride passivation layer are sintered to decompose the resin in the composite coating layer, the glass powder is etched through the silicon nitride passivation layer, and the metal wire is connected to the upper surface of the substrate to form a conductive path.

[0015] S5. Cool the conductive path to obtain the gate circuit board.

[0016] Preferably, the sintering is performed at high temperature using a heating device.

[0017] Preferably, the heating method of the heating device is resistance wire heating, electric arc heating, infrared heating, microwave heating or electromagnetic induction heating.

[0018] Preferably, the coating process is a wetting process, a spraying process, a brushing process, or a vibration electrostatic adsorption process.

[0019] Preferably, the specific steps of the vibration electrostatic adsorption process are as follows:

[0020] The resin micro-nano particles and glass powder micro-nano particles are mixed evenly to form composite coating particles;

[0021] The composite coating particles are made to smoke by a vibration device;

[0022] The electrostatically charged metal wire is placed above the vibrating composite coating particles;

[0023] The composite coating particles are adsorbed onto the surface of the metal wire by the adsorption effect of an electrostatic device.

[0024] During subsequent high-temperature heating, the composite coating particles are melted and sintered together with the substrate.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: a composite coating layer, which is a composite material layer of resin and glass powder, is applied around the metal wire; a silicon nitride passivation layer is provided on the upper surface of the substrate; the metal wire is cured and bonded to the substrate through the composite coating layer; after sintering, the composite coating layer melts, and the silicon nitride passivation layer dissolves into the composite coating layer, thereby forming a conductive path between the metal wire and the substrate. This utilizes the advantage of rapid prototyping of the metal wire coated with the composite coating, simplifying the photovoltaic gate fabrication process, reducing the use of silver paste, and obtaining a photovoltaic gate with a smaller grating width and better conductivity. Attached Figure Description

[0026] The present invention will now be described in detail with reference to the accompanying drawings. The above and other aspects of the present invention will become clearer and more readily understood through the detailed description following the accompanying drawings. In the drawings:

[0027] Figure 1 This is a schematic diagram of the structure of the gate circuit board for silicon surface photovoltaic cells provided in an embodiment of the present invention;

[0028] Figure 2 This is a flowchart of the molding process for the gate circuit board of a silicon surface photovoltaic cell provided in an embodiment of the present invention;

[0029] Figure 3 This is the molding process for the gate circuit board of silicon surface photovoltaic cells provided in Embodiment 4 of the present invention;

[0030] Figure 4 This is the molding process for the gate circuit board of silicon surface photovoltaic cells provided in Embodiment 5 of the present invention.

[0031] In the figure, 1 is a metal wire, 2 is a composite coating layer, 3 is a metal wire coated with a composite coating layer, 4 is a silicon nitride passivation layer, 5 is a substrate, 6 is a heating device, 7 is a vibration device, and 8 is an electrostatic device. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0033] Example 1

[0034] Combined with appendix Figure 1 As shown, this embodiment of the invention provides a gate circuit board for silicon surface photovoltaic cells, comprising: a metal wire 1 and a substrate 5. The metal wire 1 is surrounded by a composite coating layer 2, which is a composite material layer of resin and glass powder. A silicon nitride passivation layer 4 is provided on the upper surface of the substrate 5. The metal wire 1 is bonded to the substrate 5 by curing through the composite coating layer 2. After sintering, the composite coating layer 2 melts, and the silicon nitride passivation layer 4 dissolves in the composite coating layer 2, thereby forming a conductive path between the metal wire 1 and the substrate 5. This utilizes the rapid prototyping advantage of the coated metal wire 3, simplifying the photovoltaic gate fabrication process, reducing the use of silver paste, resulting in a lower photovoltaic gate width, and achieving a photovoltaic gate with a smaller grating width, higher reliability, and better conductivity.

[0035] In this embodiment, the resin in the composite coating layer 2 is made of polyethylene, epoxy resin, polyethylene terephthalate, polymethyl methacrylate, or other resins with a decomposition temperature below 500°C.

[0036] In this embodiment, the glass powder in the composite coating layer 2 is glass powder or other glass powder with a particle size of 0.01-10 micrometers.

[0037] Specifically, the glass powder in the composite coating layer 2 can be improved by selecting the type of resin and the particle size of the glass powder in the composite coating layer 2, adjusting the ratio of resin to glass powder, and adjusting the amount of composite coating layer 2 adhering to the surface of the metal wire 1, thereby enhancing the bonding force and conductivity between the metal wire 3 coated with the composite coating layer and the substrate 5 to meet the usage requirements.

[0038] Specifically, the composite coating layer 2 is a mixture of high-viscosity resin and glass powder with a decomposition temperature below 500°C. When the composite coating layer 2 is on the periphery of the metal wire 1, the adhesiveness of the composite coating layer helps to adhere the metal wire 1 to the upper surface of the passivation layer. During high-temperature sintering of the grating to be processed, the resin in the composite coating layer 2 decomposes, and the glass powder corrodes the silicon nitride passivation layer 4, causing the metal wire 1 to bond with the substrate 5, thus achieving a conductive path.

[0039] Preferably, the glass powder in the composite coating layer 2 is glass powder, low melting point glass powder, or other glass powder with a particle size of 0.05-10 micrometers.

[0040] In this embodiment, the metal wire 1 is a copper wire, silver wire, gold wire, iron wire, aluminum wire, tungsten wire, alloy, or a conductive metal wire 1 with a metal coating on its surface.

[0041] In this embodiment, due to the high viscosity of the resin in the composite coating layer 2, the metal wire 1 coated with the composite coating layer 2 can be quickly formed on the silicon nitride passivation layer 4 on the surface of the substrate 5. High-temperature sintering by the heating device 6 allows the metal wire 1 to bond with the substrate 5, forming a conductive path. The bonding force and conductivity between the metal wire 1 and the substrate 5 can be controlled by adjusting the ratio of resin to glass powder.

[0042] Example 2

[0043] like Figure 2 As shown, this embodiment of the invention provides a molding process for a gate circuit board for a silicon surface photovoltaic cell, used to prepare the gate circuit board for a silicon surface photovoltaic cell as described above. The molding process includes the following steps:

[0044] S1. The glass powder is uniformly dispersed in epoxy resin to form a composite coating;

[0045] S2. Immerse the metal wire 1 in the composite coating and coat the surface of the metal wire 1 with a layer of the composite coating.

[0046] S3. A silicon nitride passivation layer 4 is deposited on the substrate 5 to obtain a substrate 5 with a passivated surface. A metal wire 1 with the composite coating on its surface is attached to the substrate 5 so that the composite coating is in contact with the silicon nitride passivation layer 4.

[0047] S4. The composite coating and the silicon nitride passivation layer 4 are sintered to decompose the resin in the composite coating layer 2, the glass powder is etched through the silicon nitride passivation layer 4, and the metal wire 1 is connected to the upper surface of the substrate 5 to form a conductive path.

[0048] S5. Cool the conductive path to obtain the gate circuit board.

[0049] Specifically, the gate circuit board obtained through steps S1-S5 includes a molding process in which a composite coating layer 2 is coated on the surface of a metal wire 1. The resin in the composite coating layer 2 is a high-viscosity resin with a decomposition temperature below 500°C; the glass powder in the composite coating layer 2 is 0.01-10 micrometer glass powder; the metal wire 1 coated with the composite coating layer 2 is then attached to a photovoltaic panel; the photovoltaic gate to be processed is sintered at high temperature. After the metal wire 1 coated with the composite coating layer 2 is sintered at high temperature, the resin in the composite coating layer 2 decomposes, and the glass powder in the composite coating layer 2 penetrates the silicon nitride passivation layer 4. The metal wire 1 and the substrate 5 form a conductive circuit, and the photovoltaic gate fabrication is completed. This invention makes the fabrication of silicon-based surface photovoltaic gate circuits simpler and more convenient, and provides good conductivity.

[0050] In this embodiment, the sintering is carried out at high temperature by heating device 6.

[0051] In this embodiment, the heating method of the heating device 6 is resistance wire heating, electric arc heating, infrared heating, microwave heating or electromagnetic induction heating.

[0052] In this embodiment, the coating process is a wetting process, a spraying process, a brushing process, or a vibration electrostatic adsorption process.

[0053] In this embodiment, the specific steps of the vibration electrostatic adsorption process are as follows:

[0054] The resin micro-nano particles and glass powder micro-nano particles are mixed evenly to form composite coating particles;

[0055] The composite coating particles are made to smoke by the vibration device 7.

[0056] The electrostatically charged metal wire 1 is placed above the vibrating composite coating particles;

[0057] The composite coating particles are adsorbed onto the surface of the metal wire 1 by the adsorption effect of the electrostatic device 8.

[0058] During subsequent high-temperature heating, the composite coating particles are melted and sintered together with the substrate 5.

[0059] Example 3

[0060] like Figure 1 As shown, the present invention provides a forming process for the gate circuit of a silicon-based surface photovoltaic cell, comprising the following steps:

[0061] S31. Glass powder with a diameter of 0.5 micrometers is uniformly dispersed in epoxy resin to form a composite coating;

[0062] S32. Immerse a copper wire with a diameter of 20 micrometers into the above composite coating and coat the surface of the copper wire with a layer of composite coating.

[0063] S33. A copper wire with a composite coating is attached to the surface of the substrate 5, and the composite coating is in contact with the silicon nitride passivation layer 4.

[0064] S34. The photovoltaic grid to be processed is sintered at high temperature. The epoxy resin in the composite coating is decomposed. The glass powder in the composite coating etches the silicon nitride passivation layer 4. The metal wire 1 contacts the substrate 5 to form a conductive circuit.

[0065] Example 4

[0066] like Figure 3 As shown, the present invention provides a forming process for the gate circuit of a silicon-based surface photovoltaic cell, comprising the following steps:

[0067] S41. Glass powder with a diameter of 0.3 micrometers is uniformly dispersed in epoxy resin to form a composite coating;

[0068] S42. Immerse a silver-plated copper wire with a diameter of 18 micrometers into the above composite coating and coat the surface of the copper wire with a layer of composite coating.

[0069] S43. Heat the substrate 5 at high temperature;

[0070] S44. A silver-plated copper wire with a composite coating is attached to the surface of a high-temperature substrate 5. The glass powder in the composite coating etches the silicon nitride passivation layer 4, and the metal wire 1 contacts the substrate 5 to form a conductive circuit.

[0071] Example 5

[0072] like Figure 4 As shown, the present invention provides a forming process for the gate circuit of a silicon-based surface photovoltaic cell, comprising the following steps:

[0073] S51. Glass powder with a diameter of 0.2 micrometers is mixed evenly with polyethylene powder particles to form a composite coating powder;

[0074] S52. The composite coating powder is atomized by the high-frequency vibration of the vibration device 7.

[0075] S53. Place the silver wire above the atomized composite coating powder and pass an electric current through the silver wire so that the silver wire adsorbs the composite coating powder through electrostatic action.

[0076] S54. The silver wires with composite coating powder are attached to the photovoltaic material.

[0077] S55. The photovoltaic grid to be processed is sintered at high temperature, and the silver wire contacts the substrate 5 to form the grid circuit.

[0078] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0079] The embodiments of the present invention have been described above with reference to the accompanying drawings. The disclosed embodiments are merely preferred embodiments of the present invention. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many equivalent changes in form without departing from the spirit and scope of the claims of the present invention, and all such changes are within the protection scope of the present invention.

Claims

1. A gate circuit board for silicon surface photovoltaic cells, characterized in that, include: The metal wire and the substrate, wherein the metal wire is surrounded by a composite coating layer, which is a composite material layer of resin and glass powder; The upper surface of the substrate is provided with a silicon nitride passivation layer; the metal wire is cured and bonded to the substrate through the composite coating layer. After sintering, the composite coating layer melts, and the silicon nitride passivation layer dissolves in the composite coating layer, so as to form a conductive path between the metal wire and the substrate. The resin in the composite coating layer is made of polyethylene, epoxy resin, polyethylene terephthalate, polymethyl methacrylate, or other resins with a decomposition temperature below 500°C.

2. The gate circuit board for silicon surface photovoltaic cells as described in claim 1, characterized in that, The glass powder in the composite coating layer is glass powder or other glass powder with a particle size of 0.01-10 micrometers.

3. The gate circuit board for silicon surface photovoltaic cells as described in claim 1, characterized in that, The metal wire is a copper wire, silver wire, gold wire, iron wire, aluminum wire, tungsten wire, alloy, or a conductive metal wire with a metal coating.

4. A forming process for a gate circuit board for a silicon surface photovoltaic cell, used to prepare the gate circuit board for a silicon surface photovoltaic cell as described in any one of claims 1-3, characterized in that, The molding process includes the following steps: S1. The glass powder is uniformly dispersed in epoxy resin to form a composite coating; S2. Immerse the metal wire in the composite coating and coat the surface of the metal wire with a layer of the composite coating. S3. A silicon nitride passivation layer is deposited on the substrate to obtain a substrate with a passivated surface, and a metal wire with the composite coating on its surface is attached to the substrate so that the composite coating is in contact with the silicon nitride passivation layer. S4. The composite coating and the silicon nitride passivation layer are sintered to decompose the resin in the composite coating layer, the glass powder is etched through the silicon nitride passivation layer, and the metal wire is connected to the upper surface of the substrate to form a conductive path. S5. Cool the conductive path to obtain the gate circuit board; The coating process includes a vibration electrostatic adsorption process; The specific steps of the vibration electrostatic adsorption process are as follows: The resin micro-nano particles and glass powder micro-nano particles are mixed evenly to form composite coating particles; The composite coating particles are made to smoke by a vibration device; The electrostatically charged metal wire is placed above the vibrating composite coating particles; The composite coating particles are adsorbed onto the surface of the metal wire by the adsorption effect of an electrostatic device. During subsequent high-temperature heating, the composite coating particles are melted and sintered together with the substrate.

5. The forming process for the gate circuit board of silicon surface photovoltaic cells as described in claim 4, characterized in that, The sintering is carried out at high temperature by a heating device.

6. The forming process for the gate circuit board of silicon surface photovoltaic cells as described in claim 5, characterized in that, The heating method of the heating device is resistance wire heating, electric arc heating, infrared heating, microwave heating or electromagnetic induction heating.

7. The forming process for the gate circuit board of silicon surface photovoltaic cells as described in claim 4, characterized in that, The coating process can be a wetting process, a spraying process, or a brushing process.

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