The Art and Science of Soldering

Reliable soldering is about heat transfer and flux chemistry, not just melting metal. IPC-J-STD-001 defines the requirements for soldered electrical and electronic assemblies.

A common mistake is applying solder to the iron tip and carrying it to the joint. The flux burns off instantly, resulting in a cold, brittle joint. You must heat the pad and component lead simultaneously, then apply solder to the joint.

Key Specifications Data

Solder TypeMelting PointProsCons
63/37 (Leaded)183°C (Eutectic)Easy to use, shiny jointsToxic (RoHS restricted)
SAC305 (Lead-Free)~217°CRoHS compliantHigher heat required, dull joints

Frequently Asked Questions

What does flux do?

It removes oxidation from the metal surfaces allowing the solder to wet (bond) properly to the copper and component lead.

What temperature should my iron be?

Typically 300-350°C for leaded solder, and 350-400°C for lead-free, depending on the thermal mass of the joint.