Solder paste is applied to surface mount boards prior to pick and place and when passed through an infra-red reflow machine, melts to provide the soldered joints. ... Solder paste is used in PCB assembly as it provides significant advantages and its form enables the process to become a simple and easy process.

What do you use solder paste for?

Solder paste is commonly used to create electrical connections and mechanical bonds between printed circuit board pads and surface mount devices, such as resistors and capacitors. It is made up of powdered solder in a flux paste.

Is soldering paste necessary?

For a good soldered joint, the proper amount of solder paste must be used. Too much paste may result in a short circuit; too little may result in poor electrical connection or physical strength.