A production line for producing electronic modules including a printed-circuit board, at least one first-type component, and at least one second-type component, wherein the production line includes a unit for putting the first-type component in place, a general heating unit for melting a solder placed between the at least one first-type component and the circuit, a unit for putting the second-type component in place, and a local heating unit for melting a solder placed between the at least one second-type component and the circuit.

The invention provides a spacer for soldering comprising an elongate body having one end provided with a tapped hole and an opposite end provided with a transverse bearing surface having a smooth centering peg projecting therefrom, the peg has a longitudinal outer passage extending over at least a fraction of its length as far as the transverse bearing surface to enable molten solder to penetrate by capillarity as far as the transverse bearing surface. The invention also provides a module including such a spacer.