The invention relates to a preparation method for a stannum,
indium and stibium series lead-free solder
tinning copper strip used for a
solar battery. The preparation method comprises the following steps: pure stannum,
indium and stibium, as well as
bismuth,
copper and silver are weighted according to the
mass ratio of (83-99):(0.5-9):(0.1-8):(0-4):(0-1):(0-1); firstly, stibium,
copper and silver are melted along with stannum in a
smelting furnace in the proportion of 1:10 and then stirred to enable the stibium, copper and silver to be completely melted in stannum, and a stannum, stibium, silver and copper intermediate
alloy is formed; secondly, the residual stannum and the other components are melted to form corresponding intermediate alloys; then two intermediate alloys are melted and stirred to be evenly mixed; and finally, the traditional hot dip-
soldering process is used, and lead-free solder is dip-soldered on a
copper wire or a copper strip. The Sn-In-Sb series lead-free solder has very low silver content, the solder cost is greatly lowered, the copper strip has better
ductility and tensile strength, and the connection interface has high reliability. The high-performance
solder alloy is taken as the object of study and is enabled to meet the industrial application requirements, so that the development prospect is good.