The invention relates to a lead-free glass
powder for
silver paste on the back of a
crystalline silicon solar cell and a preparation method thereof. The lead-free glass
powder comprises the following raw materials in parts by weight: 40-70 parts of Bi2O3, 5-15 parts of B2O3, 0.5-5 parts of ZrO2, 10-20 parts of SiO2, 5-20 parts of ZnO, 1-5 parts of TiO2, 5-20 parts of Al2O3 and 1 part of P2O5. The preparation method comprises the following steps of: placing the raw materials in a mixer, and uniformly mixing to form a mixture; preheating a
quartz crucible to 600-800 DEG C, placing the mixture in the
quartz crucible and carrying out heat preservation for 20 minutes; then
smelting for 20 minutes to 40 minutes at 900-1200 DEG C; pouring
molten glass into deionized water for
quenching, carrying out wet-process ball milling on the quenched glass to 2-5mu m, and
drying to obtain the lead-free glass
powder. The lead-free glass powder has the advantages that the technological process is simple, time consumption for
smelting is short and cost is low; when in use, the lead-free glass powder has good wettability with silver powder and a
silicon substrate; and after the lead-free glass powder is sintered, the
adhesive force between the lead-free glass powder and the
silicon substrate is above 5N.