Lead-free back silver paste for crystalline silicon solar cell and preparation method thereof

Abstract

The invention relates to an unleaded back silver paste used for a crystalline silicon solar cell and a preparation method of the unleaded back silver paste used for the crystalline silicon solar cell. Raw materials comprise 60 parts of aluminum powder, 29-42 parts of organic binding agents and 1-10 parts of inorganic binding agents, the organic binding agents comprise 40-70 parts of terpilenol, 5-10 parts of butyl carbitol, 5-10 parts of butyl carbitol acetic ester, 3-10 parts of ethyl cellulose, 5-15 parts of diethyl phthalate and 2 parts of sorbitol anhydride stearate, and the inorganic binding agents comprise 30-60 parts of Bi2O3, 5-15 parts of B2O3, 1-2 parts of NaF, 10-20 parts of SiO2, 5-10 parts of ZnO, 1-5 parts of TiO2, 10-20 parts of Al2O3 and 2 parts of P2O5. After being mixed evenly, the components are rolled until the fineness degree is smaller than or equal to 10 microns, and viscosity is 30-100 Pa.s. The unleaded back silver paste used for the crystalline silicon solar cell is high in adhesive force and good in weldability and welding resistance.

Description

technical field [0001] The invention relates to an electronic paste for a crystalline silicon solar cell, in particular to a lead-free back silver paste for a crystalline silicon solar cell, and a method for preparing a lead-free back silver paste for a crystalline silicon solar cell, which belongs to solar cells technology field. Background technique [0002] As a green and clean energy, solar energy has been valued by various countries in the world. The silver paste on the back of the solar cell is an important part of the solar cell. It must provide excellent adhesion and solderability, and at the same time have a lower contact resistance to ensure the stability and reliability of the cell assembly. [0003] The silver paste on the back of the solar cell is mainly composed of silver powder, inorganic binder and organic binder. As the functional phase in the paste, the silver powder plays a conductive role. The inorganic binder plays the role of bonding with the crystal...

AI Technical Summary

Problems solved by technology

[0005] 1. The slurry contains Pb, Cr and other toxic substances, which are very harmful to the environment and human body;

[0006] 2. The adhesion between the silver electrode and the silicon substrate is poor, and the battery life is short;

[0007] 3. Silver electrodes have poor solderability and solder resistance, and there are phenomena such as false soldering and over-soldering, and the scrap rate of cells is high

[0008] The silver powder used in the paste is spherical silver powder, which shrinks greatly during sintering, resulting in poor compactness of the film after sintering, high square resistance, and poor electrical properties

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