How a Computer Works (2015)

13. PCB

Printed Circuit Board

The printed circuit board (PCB) contains components such as microchips, resistors, capacitors and connectors for plugging in peripherals.

The motherboard is the largest circuit board in the computer.

Multilayer

Circuit boards have arrays of copper tracks on each side of the board. Extra boards can be glued together to form a multilayer circuit board.

An extra board is used when connection lines would otherwise cross and short out on other connections.

Socket

All components are soldered to the copper tracks on the circuit board. Where components may need replacing in the future like the CPU, sockets are used where the microchip can be replaced easily.

This makes upgrading the computers processor easy as un-soldering lots of solder joints would probably ruin the circuit board.

The substrate of the board is usually glass fibre with the tracks etched onto the board.