Back to Courses

PCB Design & Manufacturing

From schematic to finished circuit board

What is a PCB?

A Printed Circuit Board (PCB) is a board made of fiberglass or composite material with copper traces that electrically connect components. It replaces point-to-point wiring with a manufactured board.

PCB Design Process

  1. Schematic Design: Draw circuit diagram with symbols
  2. Component Selection: Choose parts with correct footprints
  3. PCB Layout: Place components and route traces
  4. Design Rule Check (DRC): Verify clearances and connectivity
  5. Generate Gerber Files: Manufacturing files for PCB fab
  6. Manufacturing: Send to PCB manufacturer
  7. Assembly: Solder components to board

Key Design Rules

Trace Width

Wider traces carry more current. Typical: 0.25mm for signals, 0.5-2mm for power.

Rule of thumb: 1mm width per 1A current

Clearance

Minimum spacing between traces. Typical: 0.2-0.3mm for low voltage.

Via Size

Holes connecting layers. Typical: 0.3-0.8mm drill diameter.

Ground Planes

Large copper areas for low impedance return path and shielding.

Layer Stack-up

  • • Single-layer: Components on top, traces on bottom
  • • Double-layer: Traces on both sides, most common for hobbyists
  • • 4-layer: Signal-Ground-Power-Signal, better for high-speed
  • • 6+ layers: Complex designs, better signal integrity

Surface Finish & Soldering

HASL (Hot Air Solder Leveling)

Most common, tin-lead coating, good for hand soldering

ENIG (Electroless Nickel Immersion Gold)

Flat surface, excellent for fine-pitch components

Solder Mask

Protective layer (usually green) preventing solder bridges

Silkscreen

White labels showing component designators and info

Common PCB Software

  • • KiCad: Free, open-source, professional quality
  • • Eagle: Popular hobbyist tool (Autodesk)
  • • Altium Designer: Professional, industry standard
  • • EasyEDA: Browser-based, integrated with JLCPCB