Solar panel manufacturers today give you the production process of popular science solar panels.
10 steps, including slicing, cleaning, preparation of suede, etching around the perimeter, removal of PN+ knot on the back, making upper and lower electrodes, making anti-reflective coating, sintering, and testing binning.
Instructions for the specific manufacturing process of solar cells
(1) Slicing: Multi-wire cutting is used to cut the silicon rod into square silicon wafers.
(2) Cleaning: Clean with conventional silicon wafer cleaning methods, and then use acid (or alkali) solution to remove the cutting damage layer on the surface of the silicon wafer for 30-50um.
(3) Preparation of suede: Anisotropic corrosion of the silicon wafer with alkali solution to prepare suede on the surface of the silicon wafer.
(4) Phosphorus diffusion: The coating source (or liquid source, or solid phosphorus nitride flake source) is used for diffusion to make PN+ knot, and the knot depth is generally 0.3-0.5um.
(5) Peripheral etching: The diffusion layer formed on the surrounding surface of the silicon wafer during diffusion will cause a short circuit between the upper and lower electrodes of the battery, and the surrounding diffusion layer will be removed by masking wet corrosion or plasma dry corrosion.
(6) Remove the PN+ knot on the back. Wet etching or grinding disc method is commonly used to remove the PN+ knot on the back.
(7) Making upper and lower electrodes: using vacuum evaporation, electroless nickel plating or aluminum paste printing and sintering. Make the lower electrode first, then the upper electrode. Aluminum paste printing is a process method that is widely used.
(8) Making an anti-reflective coating: In order to reduce the loss of incoming reflection, the surface of the silicon wafer should be covered with an anti-reflective coating. The materials for making anti-reflective coating are MgF2, SiO2, Al2O3, SiO, Si3N4, TiO2, Ta2O5, etc. The process method can be vacuum coating method, ion coating method, sputtering method, printing method, PECVD method or spraying method.
(9) Sintering: The battery chips are sintered on a nickel or copper baseplate.
(10) Test classification: according to the specified parameter specifications, test classification. The process of producing cells is relatively complex, and generally needs to go through the main steps such as silicon wafer inspection, surface texturing, diffusion knotting, dephosphorization silica glass, plasma etching, anti-reflective coating, screen printing, rapid sintering, and detection and packaging.