A typical printed circuit board (PCB) contains a large number of electronic components. These components are held on the board through bonds between their terminals or pins and the pads on the PCB. The process of creating these bonds is called soldering, where a metal alloy is melted at the interface of the pad and the terminal and then allowed to cool down and solidify. The resultant bond not only holds the component on the PCB but also provides the electrical connection between the component and the board.
Instructions
Soldering Surface Mount Components
1 Turn the soldering iron on and set it at a temperature of 400 degrees Fahrenheit.
2 Place the PCB on a flat and dry surface with component side facing up.
3 Identify the pads on the board where the component is to be soldered. Melt a small solder on any one of these pads. This can be done by holding the soldering wire on the pad and touching the interface of the wire and the pad with the soldering iron tip. The solder will melt and cover the pad.
4 Hold the component to be soldered with tweezers and place it on the board such that its terminals are aligned with the PCB pads. Note that the component will be slightly tilted due to the solder on one of the pads.
5 Gently press the component from the top with the tip of the tweezers and briefly touch the soldered pad with the soldering iron tip. As soon as you see that the solder has melted and the component has sunk to the base of the board, retract the solder.
6 Solder the next terminal. Hold the soldering wire at the interface of the terminal and the pad and touch it with the soldering iron tip. The solder will melt and flow on the pad in less than 3 seconds. Retract the solder wire and the soldering iron tip and repeat this process to solder the rest of the terminals.
Soldering Through-Hole Components
7 Turn the soldering iron on and set it at a temperature of 400 degrees Fahrenheit.
8 On the component side of the board, identify the holes corresponding to the component's leads. Insert the leads in these holes and slightly bend them on the other side of the board so that the component does not fall off when the board is turned over for soldering.
9 Turn the PCB over and put it on a flat and dry surface with component side facing down.
10 Hold the solder wire at the interface of any one of the leads and its pad and touch it with the soldering iron tip. The solder will melt and cover the pad within 3 seconds. Retract the soldering iron tip and the solder wire. Repeat this process to solder the remaining leads of the component.
11 Cut off the excess leads of the component with a wire cutter.
