Basic PCB and PCBA Terms Glossary

The A stands is for assembly. The bare PCB with components placed on it.

A modern method of assembling circuit boards where tiny electronic components are placed directly onto the surface of the board—usually by automated machines. It’s faster, more efficient, and allows for smaller, more compact designs compared to older methods.

Refers to the size of an SMT component. An 0603 size component for example, is approximately 1/16″

Refers to the distance between a components electrical connections.

Pick & Place is the process of picking up tiny electronic parts from a reel or tray, and placing them onto a PCB. It can be done by hand or with a precision machine that moves very quickly.

Thru-hole means parts that go through small plated holes in the PCB before being soldered. This makes the parts extra secure. It’s often used for big components like switches, relays, LEDs, and connectors. Often hand soldered for added precision and durability.

Manufacturers packaging of components that allow hundreds or thousands of parts to be on a plastic reel. It looks like a reel to reel audio tape cartridge.

Hot Air Surface Leveling, is a term used to describe hot air, blowing excess solder from component mounting pads, on a bare PCB.

This leaves behind a thin layer of solder on the PCB component  mounting pads, to allow for the reflow solder automation process. It is a miniature version of the “air curtain” that you walk through, while entering a store.

The thin lines of copper on a PCB that carry electricity, like tiny electrical highways.

PCBs can have one layer of copper (single-layer), or multiple layers stacked together (multi-layer) for more complex circuits.

A tiny hole in a PCB that lets electricity pass between different layers, like an elevator in a building.

The printed text and symbols on a PCB that label components and make assembly easier.

The most common material used for making PCB boards. It’s a strong, heat-resistant plastic with fiberglass inside.

The reference point for electrical circuits, like the “zero” point in a number system.

The electrical pressure that moves current through a circuit, like water pressure in a hose.

The flow of electricity in a circuit, like how much water is moving through a pipe.

A material’s opposition to electrical flow, like a thin straw making it harder to drink a thick milkshake.