Overview

Soldering is used today to make electrical connections. Modern electronic systems are formed from thousands of components connected by soldering. If any connection fails, the system could stop working, resulting in loss of time, money, or even lives. Therefore, good soldering technique is important to ensure reliable electrical connections.

Solder melts at high temperature and lows to cover the surface of the connections. When it cools, the solder solidifies and a good electrical connection is formed. For solder to flow easily, the metal surface must be free of grease, dirt, or paint, very much like how water wets a non-waxed surface.

Besides a dirty surface, another barrier to wetting is the oxide layer that forms when metal is exposed to air. In fact, as you solder, oxidation is accelerated due to the heat. A substance called flux can be used to remove the oxide layer. Flux can be applied manually or in some cases, it is embedded in the solder.

PART 1: Prepare the Solder Iron

  1. Switch on the soldering iron and place it in its stand. Wait a few minutes for the soldering iron to reach its working temperature.
  2. Dampen the sponge in the stand.
  3. Melt some solder on the top of the soldering iron, and then wipe the tip with the sponge to clean off any excess solder. This step is called tinning, which helps to clean the tip and speed up the heat flow later.

Here are some safety precautions:

PART 2: Prepare the Circuit Board

PART 3: Solder the Components

  1. Mount the component on the circuit board.

  2. Bend the leads to hold the component.

  3. Solder the leads to the copper track.

  4. Cut off the leads.

PART 4: Identify Good Soldering Joint

A good soldering joint is shiny and has a volcano shape.