Method and device for producing soft solder powder

摘要

A method and device for producing soft solder powder without pressure, in particular for producing spherical fine metal particles having a grain size ranging from 1-100 microns and a Liquidus temperature <250oC. The method comprises: a) gravity feeding melted solder into an oil receiver while setting a volume ratio of melted solder to oil to at least 10:1; b) dispersing the melted solder by agitating and by subsequent shearing steps according to the rotor/stator principle using a rotor with a rotational speed ranging from 1500-5000 rpm while adding oil from the receiver of step a); c) recirculating the solder/oil mixture of step b) at least twenty times in a circuit through the above shearing steps; d) transferring the solder/oil mixture from the circuit of step c) into another oil receiver for separating off the dispersed material by sedimentation and returning the oil to the receiver of step b) and/or a); and e) extracting and feeding the dispersed material of step d) for a subsequent washing.