A solder preform is a solid, flat, manufactured-shape of solder that can be used for a wide variety of assembly applications. Solder preforms can come in a wide variety of alloys.

Can you solder without flux?

Yes, solder can be used without flux. To do so, you will need something other than flux to break down the oxides on the metal surface, without which your surface may be damaged or not properly cleaned.

How does solder paste work?

Solder paste is a combination of a powder made up of metal solder particles and sticky flux that has the consistency of putty. The flux not only does its usual job of cleaning the soldering surfaces of impurities and oxidation, but it also provides a temporary adhesive that holds the surface mount components in place.