A method of soldering and a preform therefor

摘要

A solder preform 20 is placed between two surfaces to be joined together. The preform has at least three solder wire limbs 21 which radiate outwardly from a centre 22. A cruciform shape is particularly advantageous. When the solder is heated, molten solder flows and expels trapped air from between the surfaces, thus reducing the void area in the joint which forms when the solder solidifies. The method and preform are particularly applicable to manufacture of opto-electronic modules.