Lead-free silver and aluminum slurry for solar photocell and preparation method of slurry

Abstract

The invention discloses lead-free silver and aluminum slurry for a solar photocell. The slurry is prepared from raw materials in percent by mass as follows: 75-80% of silver powder, aluminum powder and copper powder, 15-20% of organic bond, 1-5% of inorganic glass powder, and 1-5% of additive; the purities of the silver powder, the aluminum powder and the copper powder are more than or equal to 99.9%; the organic bond is prepared from the following materials in percent by mass of: 0.5-2% of butyl carbitol, 1-2.5% of resin, 1-4% of rosin, 11-13% of ethylene glycol monomethyl ether, 5-9% of diethylene glycol monobutyl ether, 65-75% of cyclohexanone and 10-20% of n-butyl alcohol; the inorganic glass powder is prepared from the following materials in percent by mass of: 1-3% of titanium dioxide, 55-75% of boric acid, 3-5% of aluminium sesquioxide, 15-25% of antimony oxide and 2-5% of zirconium oxide; and the additive is prepared from the following materials in percent by mass of: 35-45% of span and 55-65% of pump oil. The lead-free silver and aluminum slurry prepared by the raw material has the advantages of good weldability and strong adhesion and meets the lead-free environmental friendless requirement.

Description

technical field [0001] The invention relates to an electronic paste for solar silicon cells, in particular to a lead-free silver-aluminum paste for solar photovoltaic cells and a preparation method thereof. Background technique [0002] Solar energy is an inexhaustible, pollution-free, noise-free new energy source. Solar cells are green and environmentally friendly renewable energy semiconductor devices that directly convert solar energy into electrical energy. The preparation of its electronic paste is mostly made of silver paste, silver-aluminum paste, and aluminum paste. Aluminum paste has cheap price and stable electrical performance. Aluminum and silicon are easy to form PN junctions, have long-wave response characteristics, have good ohmic contact characteristics with silicon wafers or ceramic substrates, and have good aging resistance. Therefore aluminum electronic paste is selected as the material for the back field of silicon solar cells. [0003] In order to re...

AI Technical Summary

Problems solved by technology

[0005] The inorganic glass powder used in the known solar silicon photocell aluminum electronic paste generally contains lead, which will pollute the environment during the production and use of the paste