LOW TEMPERATURE SOLDERING SOLUTIONS FOR POLYMER SUBSTRATES, PRINTED CIRCUIT BOARDS AND OTHER JOINING APPLICATIONS.

Abstract

A welding alloy comprising: 40 to 65% by weight bismuth; 1 to 10% by weight indium; at least one of: 0.1 to 5% by weight gallium, 0.1 to 5% by weight zinc, 0.1 to 2% by weight copper, 0.01 to 0.1% by weight cobalt, 0.1 to 2% by weight silver, 0.005 to 0.05% by weight titanium, and 0.01 to 1% by weight nickel; optionally one or more of: up to 1% by weight of vanadium, up to 1% by weight of rare earth metals, up to 1% by weight of neodymium, up to 1% by weight of chromium, up to 1% by weight of iron, up to 1% by weight of aluminum, up to 1% by weight of phosphorus, up to 1% by weight of gold, up to 1% by weight of tellurium, up to 1% by weight of selenium, up to 1% by weight of calcium, up to 1% by weight of vanadium, up to 1% by weight of molybdenum, up to 1% by weight of platinum, up to 1% by weight of magnesium, up to 1% by weight of silicon and up to 1% by weight of manganese; and the balance is tin together with any unavoidable impurities.