CN-118448479-B - Grid circuit board for silicon surface photovoltaic cell and forming process thereof

CN118448479BCN 118448479 BCN118448479 BCN 118448479BCN-118448479-B

Abstract

The invention provides a grid circuit board for a silicon surface photovoltaic cell and a forming process thereof, comprising a metal wire and a substrate, wherein a composite coating layer is arranged on the periphery of the metal wire, the composite coating layer is a composite material layer of resin and glass powder, a silicon nitride passivation layer is arranged on the upper surface of the substrate, the metal wire is solidified and attached to the substrate through the composite coating layer, after sintering, the composite coating layer is melted, and the silicon nitride passivation layer is dissolved in the composite coating layer, so that a 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 flow of the photovoltaic grid, reduce the use of silver paste, and obtain the photovoltaic grid with smaller grating width and better conductivity.

Inventors

YANG GUANNAN
HE XIAOLING
ZHANG WENJIAN
Lin Guishuo
XU YIYANG
CUI CHENGQIANG

Assignees

广东工业大学

Dates

Publication Date: 20260512
Application Date: 20240418

Claims (7)

1. The grid circuit board for the silicon surface photovoltaic cell is characterized by comprising a metal wire and a substrate, wherein a composite coating layer is arranged on the periphery of the metal wire, the composite coating layer is a composite material layer of resin and glass powder, and a silicon nitride passivation layer is arranged on the upper surface of the substrate; the resin in the composite coating layer is made of polyethylene, epoxy resin, polyethylene terephthalate, polymethyl methacrylate or other resins with decomposition temperature lower than 500 ℃.
2. The grid wiring board for a silicon surface photovoltaic cell according to claim 1, wherein the glass frit in the composite coating layer is glass frit or other glass frit having a particle size of 0.01-10 μm.
3. The grid wiring board for a silicon surface photovoltaic cell according to claim 1, wherein the metal wire is a copper wire, a silver wire, a gold wire, an iron wire, an aluminum wire, a tungsten wire, an alloy, or a conductive metal wire coated with a metal on the outer surface.
4. A process for forming a gate wiring board for a silicon surface photovoltaic cell for preparing a gate wiring board for a silicon surface photovoltaic cell according to any one of claims 1 to 3, comprising the steps of: s1, uniformly dispersing the glass powder in epoxy resin to form a composite coating; s2, immersing the metal wire into the composite coating, and coating a layer of the composite coating on the surface of the metal wire; S3, depositing a silicon nitride passivation layer on the substrate to obtain a substrate with a passivated surface, and attaching a metal wire with the surface coated with the composite coating on the substrate so as to enable the composite coating to be in contact with the silicon nitride passivation layer; S4, sintering the composite coating and the silicon nitride passivation layer to decompose resin in the composite coating layer, wherein the glass powder is corroded to penetrate through the silicon nitride passivation layer, and the metal wire is connected with the upper surface of the substrate to form a conductive path; s5, cooling the conductive path to obtain a grid circuit board; the coating process comprises a vibration electrostatic adsorption process; The vibration electrostatic adsorption process comprises the following specific steps: uniformly mixing the resin micro-nano particles and the glass powder micro-nano particles to form composite coating particles; smoke the composite coating particles through a vibration device; placing the electrostatically charged wire over the vibrating composite coating particles; Adsorbing the composite coating particles on the surface of the metal wire through the adsorption action of an electrostatic device; upon subsequent high temperature heating, the composite coating particles are melted and sintered with the substrate.
5. The molding process for a gate wiring board for a silicon surface photovoltaic cell according to claim 4, wherein the sintering is performed at a high temperature by a heating device.
6. The process for forming a gate wiring board for a silicon surface photovoltaic cell according to claim 5, wherein the heating means is resistance wire heating, arc heating, infrared heating, microwave heating or electromagnetic induction heating.
7. The process for forming a gate wiring board for a silicon surface photovoltaic cell according to claim 4, wherein the coating process is a wetting process, a spraying process or a brushing process.

Description

Grid circuit board for silicon surface photovoltaic cell and forming process thereof Technical Field The invention relates to the technical field of photovoltaic grid electrodes, in particular to a grid electrode circuit board for a silicon surface photovoltaic cell and a forming process thereof. Background In face of the increasingly serious global problems of energy resource constraint, global temperature rise and the like, china promotes the comprehensive green transformation of economic and social development, and endeavors to promote clean low-carbon development of the energy of the home country. Photovoltaic power generation has become the second largest power supply in China instead of hydropower, and becomes one of important energy sources for sustainable development in the future. In order to further expand the scale of the photovoltaic industry, deepen the application of the photovoltaic in various industries, reduce the cost of photovoltaic manufacturing, and improve the photoelectric conversion rate of the photovoltaic is a necessary way. The silicon-based surface photovoltaic cell has wide application in the photovoltaic industry, including TOPCon cells, PERC cells, IBC cells and the like, The core structure of the contact battery is composed of an ultrathin silicon oxide layer and a heavily doped polysilicon layer on the back of the battery, and the ultrathin silicon oxide layer and the heavily doped polysilicon layer form a passivation contact structure together. The silicon-based surface photovoltaic cell has high comprehensive cost performance, is easy to realize under the current technology and economic conditions, and is a main technology of the next generation photovoltaic cell. Currently, the light Fu Shanji conductive grid of silicon-based surface photovoltaic cells is commonly fabricated by screen printing. However, the silver paste is used in a large amount in the process of manufacturing the photovoltaic grid line by screen printing, so that the production cost of the grid is high. In addition, screen printing has not only complex process flow, but also a series of problems such as wider grating width, poor conductivity and the like. Disclosure of Invention The invention provides a grid circuit board for a silicon surface photovoltaic cell, and aims to solve a series of problems of troublesome manufacturing process, wider grating width, poor conductivity and the like of the existing grid circuit board. According to the first aspect, the embodiment of the invention provides a grid circuit board for a silicon surface photovoltaic cell, which comprises a metal wire and a substrate, wherein a composite coating layer is arranged on the periphery of the metal wire, the composite coating layer is a composite material layer of resin and glass powder, a silicon nitride passivation layer is arranged on the upper surface of the substrate, the metal wire is solidified and attached to the substrate through the composite coating layer, after sintering, the composite coating layer is melted, and the silicon nitride passivation layer is dissolved in the composite coating layer, so that a conductive path is formed between the metal wire and the substrate. Preferably, the resin in the composite coating layer is made of polyethylene, epoxy resin, polyethylene terephthalate, polymethyl methacrylate or other resins with decomposition temperature lower than 500 ℃. Preferably, the glass powder in the composite coating layer is glass powder or other glass powder with the particle size of 0.01-10 microns. Preferably, the metal wire is copper wire, silver wire, gold wire, iron wire, aluminum wire, tungsten wire, alloy or conductive metal wire with metal plated on the outer surface. In a second aspect, an embodiment of the present invention provides a molding process for a gate circuit board for a silicon surface photovoltaic cell, for preparing the gate circuit board for a silicon surface photovoltaic cell as described above, the molding process comprising the steps of: s1, uniformly dispersing the glass powder in epoxy resin to form a composite coating; s2, immersing the metal wire into the composite coating, and coating a layer of the composite coating on the surface of the metal wire; S3, depositing a silicon nitride passivation layer on the substrate to obtain a substrate with a passivated surface, and attaching a metal wire with the surface coated with the composite coating on the substrate so as to enable the composite coating to be in contact with the silicon nitride passivation layer; S4, sintering the composite coating and the silicon nitride passivation layer to decompose resin in the composite coating layer, wherein the glass powder is corroded to penetrate through the silicon nitride passivation layer, and the metal wire is connected with the upper surface of the substrate to form a conductive path; And S5, cooling the conductive path to obtain the grid circuit board. Preferably, the sintering is