Refers to frames or supporting frames that ensure that the components do not shift or tilt during soldering. The soldering jigs must have a low thermal mass so as not to slow down the soldering process, must not bend or warp under temperature and must compensate for the tolerances of the components.

Soldering aids are usually made of aluminum or graphite or aluminum-graphite.

The fixtures are aseemblied with the components before the soldering process by hand or with an automatic placement machine and removed again after the process. The soldering jigs are then reused until they fatigue due to the constant temperature changes and must be sorted out.