PCB Basics: Terms Every Beginner Should Know
Estimated reading time: 7 minutes
A printed circuit board (PCB) is the green (or blue, red, black…) board inside almost every electronic device. It holds your components in place and connects them with copper instead of loose wires. If you are new to PCB design, the vocabulary is the hardest part at first. This page explains the terms you will meet in Protoboard Designer in plain language, so the rest of the docs make sense.
Skim it once, then come back when a word in another guide is unfamiliar. You do not need to memorize anything.
The board itself
PCB (printed circuit board) — the physical board. "Designing a PCB" means laying out where the copper and parts go, then sending that design to a factory (a fab) to be manufactured.
Layer — a PCB is a sandwich. Each slice is a layer: copper on the outside, an insulating core in the middle, plus printed and coated layers. You design each layer separately. See Understanding PCB Layers for the full list.
Two-layer board — the most common hobby board: copper on the top and bottom, with insulation between. Enough for most projects, and the cheapest to order.
Board outline — the physical shape and size of the finished board. The factory cuts the board to this edge. In Protoboard Designer the board is always a solid, closed shape (it starts as a rectangle); you set its size in Board Settings and reshape it with the Machining tool.
Copper — how parts connect
Trace (or track) — a thin line of copper that carries a signal or power from one point to another. Traces replace wires. Wider traces carry more current — see Choosing Trace Width & Spacing.
Pad — a small copper area where a component leg (or pin) is soldered to the board. Every part sits on a group of pads.
Via — a tiny plated hole that lets a trace jump from one copper layer to another (for example, top to bottom) to get around an obstacle. In Protoboard Designer a via is simply a through-hole pad connected on both copper sides — you place it with the TH Pad tool on the Via layer. See Pads, Vias & Pad Options.
Net — all the pads and traces that are electrically the same connection. "GND" and "5V" are common nets. When two pads should be joined, they belong to the same net.
Airwire (ratsnest) — a thin straight guide line the editor draws between pads that should be connected but aren't routed with copper yet. Route a trace along it and the guide disappears. It's your "still to do" list.
Copper pour / fill — a large filled area of copper, usually used as a ground plane. It reduces noise and makes wiring ground easier.
Components & their footprints
Component — a real part: a resistor, an LED, a microcontroller, a connector.
Footprint — the copper pads + silkscreen outline that match a specific part's body and pins. You place a footprint, not the component itself. Protoboard Designer ships a library and can import KiCad footprints.
Through-hole (THT) — parts with legs that poke through drilled holes and solder on the other side. Big, sturdy, easy to hand-solder — great for beginners.
Surface-mount (SMD/SMT) — parts that solder onto pads on the surface, no leg-holes. Smaller and cheaper at scale, but fiddlier to hand-solder.
Pin 1 — the reference pin of a part. Many footprints mark it with a square pad (the rest are round). Always match Pin 1 to your part's datasheet so you don't install it backwards.
Printed & coated layers
Silkscreen — the printed text and outlines on the board (part labels like "R1", polarity marks, your logo). Purely cosmetic/informational; it carries no current.
Soldermask — the coloured coating (the classic "PCB green") that covers the copper everywhere except the pads. It stops solder bridging and protects the traces. Protoboard Designer generates it automatically around your pads.
Drill file — the list of every hole the factory must drill, with positions and sizes. Exported separately from the copper.
Files & checks
Gerber files — the standard set of files a factory reads to make your board: one file per layer, plus the drill file, zipped together. See How to Export Gerber Files.
DRC (Design Rule Check) — an automatic check that flags manufacturing problems before you order: traces too thin, copper too close together, holes too small, etc. Think of it as spell-check for your board.
Clearance — the minimum gap the fab can reliably leave between two separate pieces of copper. Get too close and the factory may reject the board (or it may short).
Factories etch copper and drill holes with real, physical tolerances. The DRC numbers (minimum trace width, clearance, drill size, annular ring…) come from what the manufacturing process can actually achieve. Staying inside them is how you get a board that works the first time.
The left toolbar at a glance
Almost everything you do lives on the left toolbar. Here's the whole set, top to bottom, so you know what each tool is for:
| Tool | What it does |
|---|---|
| Selection | Select, move, and rotate elements. Switch the selection shape (Pan & Select / Box / Lasso) and double-tap it to zoom the whole board back into view. See Find Your Way Around the Editor. |
| TH Pad | Place a through-hole pad (a drilled, solderable pad). Set the layer to Via to make a via. |
| SMD Pad | Place a surface-mount pad (no hole) on a copper layer. |
| Track | Draw a copper trace, a polygon (filled copper / ground pour), or an airwire — toggle the mode in the tool's panel. |
| Machining | One tool, three modes: Drilling (holes), Milling (internal cut-outs/slots), and Outline (board shape). |
| Keepout Zone | Mark an area where copper pours must not fill. |
| Circle | Place a copper circle (pads, fiducials, decorative copper). |
| Label | Add text (silkscreen or copper) with auto-numbering and mirroring. |
| Footprints | Browse the built-in library or import KiCad footprints. |
| Insert | Open the Insert Hub to generate geometry or import artwork (see below). |
| Net Probe | Inspect connectivity — see what's joined to what, and pad/track counts. |
| Board Settings | Grid size, units, copper/AutoGround settings, and board dimensions. |
| Export | Produce Gerber, PDF, and image outputs. |
The Insert Hub
The Insert tool opens a hub that can generate common geometry for you. Under Generate you'll find Antenna, Coil, QR / barcode, Mounting holes, and Pad & via array. Under From file it can import SVG and DXF artwork. You don't need any of that for your first board — but it's there when you grow.