ADD COMPONENTS TO A PCB

1. identify the components

The first job is to make sure you have got all your parts together and you have identified each of the components. If you’re not very familiar with electronic components and you’re not up to speed with reading resistor colour codes, then it might be a good idea to place each of the components on a sheet of paper and write the component number (for example, R1, R2, C5, U1 and so on, as printed in the PCB) next to each one.

2. Bend component leads

Next, prepare those components that have axial leads, such as resistors, by bending their leads at right angles so they can pass through the holes in the PCB. Make sure you bend the leads at the correct positions so the distance between the bent leads matches the spacing between the holes on the PCB. Use small, snipe-nose pliers, holding the pliers between the component body and the position of the bend, so you don’t stress the lead connection to the body.

3. fit components to PCB

Attach the components to the PCB by passing the leads through the appropriate holes. Then bend the leads out slightly, using snipe-nose pliers, so that they won’t fall out when you turn the board over. Alternatively, place a piece of foam rubber over all the components before turning the PCB over, to hold them in place. Because the leads of already soldered components can hinder soldering new ones, it’s a good idea to fit a few at a time, cycling through steps 3, 4 and 5.

4. Solder your components

Turn the PCB over and place it on a flat surface with the component leads facing upwards. Solder each of the component leads to their pads, following the instructions on soldering in this article. Although components are less susceptible to heat damage than they once were, because the tracks on the board can transmit heat it’s good practice to solder resistors and capacitors first, leaving the more sensitive components until last.

5. Trim component leads

Component leads are almost always longer than necessary, so the final job is to cut off any excess length. In particular, you should trim all the leads just above the solder joint. This job should be done with a pair of small wire cutters. Be aware that the excess leads are occasionally propelled some distance when they’re trimmed, and they’re also sharp. It’s a good precaution, therefore, to wear a pair of safety glasses while you’re doing this job, and to carry out the work in an suitable environment, away from small children and pets.

6. Check your work

Before you try out your circuit, check your work visually (the eagle-eyed might just notice that we’d initially wired the switches incorrectly). Give it a visual check, then make sure all the soldered joints aren’t “dry”, and check you haven’t accidentally bridged two adjacent leads. Rectify any faults you find. Next, try it out, but if it doesn’t seem to work then remove the power immediately and go back to a visual check. In this instance, also make sure all the components are in the right place and are the correct way round.