The production process of POLYCRYSTALLINE SOLAR PANELS

The production process of POLYCRYSTALLINE SOLAR PANELS is a complex and high-precision project involving multiple steps and technologies to ensure the efficiency and reliability of the final product. Polycrystalline silicon solar panels are widely used in residential, commercial and industrial solar systems due to their relatively low cost and good performance.

1. Raw material preparation
Silicon raw materials: The production of polycrystalline silicon solar panels first requires high-purity silicon raw materials. Silicon is one of the most abundant elements on earth, but in solar applications, the silicon used must reach a high purity level. Usually, silicon raw materials come from ores and are obtained through smelting and purification processes.
Production of silicon ingots: After the silicon raw materials are melted at high temperature, suitable dopants (such as phosphorus or boron) are added to adjust the conductivity properties to form polycrystalline silicon ingots. These ingots are usually square or cylindrical for subsequent cutting and processing. The molten silicon gradually cools during the crystallization process to form multiple small crystals to obtain polycrystalline silicon ingots.

2. Cutting of silicon ingots
Silicon ingot slicing: One of the key steps in making solar panels is to cut polycrystalline silicon ingots into thin slices. Using a high-precision cutting machine, the silicon ingot is cut into silicon slices with a thickness of about 200-300 microns. These silicon slices are called "silicon wafers" or "cells" and are the basic units of solar panels.
Silicon wafer processing: There will be certain scratches and residues on the surface of the silicon wafer after cutting, which needs to be chemically treated and polished to remove surface defects and improve surface smoothness. The chemicals used in the treatment process help clean the silicon wafer and remove oxides.

3. Manufacturing of cells
Doping: On the surface of the silicon wafer, dopants are introduced through a diffusion process to form p-type and n-type regions. The doping process is to place the silicon wafer in a high-temperature furnace and introduce dopants such as phosphorus or boron in the atmosphere to form n-type (negative) and p-type (positive) semiconductor regions. This process is critical to the electrical performance of the cell.
Metallization: The metallization of the cell is achieved by coating the surface of the silicon wafer with conductive metal materials (usually silver and aluminum). The process of metallization involves printing a detailed electrode pattern on the silicon wafer so that the current can be extracted from the silicon wafer. After metallization, the silicon wafer is dried and sintered to ensure good adhesion and conductivity of the metal layer.
Encapsulation: The processed cells are assembled into battery components through the encapsulation process. The encapsulation materials include the backplane, the front glass and the middle EVA (ethylene-vinyl acetate copolymer) layer. The role of these materials is to protect the cells from the external environment and ensure the structural stability of the battery panel.

4. Assembly of modules
Cell connection: Arrange the processed cells in a specific arrangement order and electrical connection method, and connect them in series or parallel with wires. Through welding or other connection methods, multiple cells are combined into a battery module to form a larger photovoltaic panel.
Encapsulation: The assembled battery module needs to be encapsulated to prevent moisture, dust and mechanical damage. The encapsulation process involves placing the battery module on the backplane, covering the front glass, and laminating it with an EVA layer. Through a hot pressing process, the layers of materials are fixed together to form a solid battery panel structure.
Testing and quality inspection: The encapsulated battery panels need to undergo rigorous testing and quality inspection. The tests include electrical performance test, photoelectric conversion efficiency test and environmental tolerance test, ensuring that each solar panel can generate electricity stably in actual use and meet relevant standards and specifications.