An electronics PCB, or printed circuit board, is made of a fiberglass-epoxy composite material, and has thin conductive copper traces that form the circuit's connections. For hobby circuit building, you'll encounter two types. The first is the through hole, having holes drilled through the board. You insert part leads through the holes and solder the leads to the copper traces on the bottom side. The other type is surface mount, where you solder on the same side as the components. Surface-mount boards can be more challenging to build, though the smaller-size parts make more compact and sophisticated circuits.
Instructions
Through Hole
1 Examine the board and note that it has copper traces on one side and markings for components on the other.
2 Identify the component that you want to solder to the board. The part must match the correct location on the board. If the part is polarized, such as a diode or transistor, identify its correct orientation on the board. If you put the wrong lead through the hole, the circuit will not work.
3 Slip the leads through the holes. The part itself must be on the board's component side. The leads will protrude through the board and out of the trace side. For some parts, such as resistors, diodes and capacitors, you may have to bend the leads 90 degrees before inserting them. Once you've inserted the part, bend the leads outward slightly so the component won't slip out.
4 Turn the board over. Touch the soldering iron's hot tip to where the copper pad and part lead meet. After a few seconds, touch the end of the solder to the heated pad and lead and let a small amount of solder flow. In the same manner, solder the component's other lead or leads. Cut the excess leads with the diagonal cutters.
Surface Mount
5 Examine the board and note it has copper traces and markings for components on the same side. Some of the traces form rectangular pads onto which you solder the parts.
6 Identify the part you wish to solder and its correct location and orientation on the board.
7 Hold the soldering iron to one pad and apply a small amount of solder. Dab some flux on the solder pads with the flux pen.
8 Hold the part with tweezers. Orient the part on the solder pads and press lightly. Touch the soldering iron to the part lead that's on the one soldered pad. This will melt the solder and hold the part to the board. Release the tweezers and set them aside. Touch the soldering iron to another lead for a few seconds, then apply a small amount of solder to it. Continue soldering each lead until the part is completely connected.
