Study on the Soft Soldering

Abstract

Pb-Sn alloys of various compositions were used as soft solders for the research Each 0.1 g of solder was put on thin copper plate which preheated to a desired temperature in the thermostat 0.5 c c of zinc-chloride solution or other fluxes was applied on the solder by pipette. Then the spread area of solder was determined by the planimeter.
(1) A maximum spread area was found at the solder of eutectic composition.
(2) In all kinds of compositions of the solders a maximum spread area was obtained at 260°C when the saturated solution of zinc-chloride was used as a flux.
Some interesting problems about the soft soldering was found in the experiment and described in this paper.