The Many Types of PCBs

When a customer says "I need PCBs," your first job is to figure out what KIND. Here are the main categories you'll meet.

By Layer Count

• Single-sided — One copper layer. Cheap, simple. Used in toys, simple appliances, LED bulbs.
• Double-sided — Two copper layers (top and bottom). Most common in basic consumer goods.
• Multilayer — 4, 6, 8, 10, 12 layers and up. Used in computers, phones, anything with dense circuitry.
• High layer count (16+) — Servers, networking equipment, telecom, defense.

By Rigidity

• Rigid PCB — Stiff, doesn't bend. Standard FR-4 boards. Most common.
• Flex PCB (Flexible) — Bendable, made of polyimide. Used where the board needs to fold or fit tight curves (cameras, hearing aids, wearables).
• Rigid-Flex — Combines rigid sections and flex sections in one board. Used in aerospace, medical implants, foldable devices. Expensive but powerful.

By Specialty

• HDI (High Density Interconnect) — Very fine traces, microvias, multiple layers of stacked vias. Found in smartphones, advanced wearables. Hard to make and expensive.
• High-Frequency / RF — Special low-loss materials (Rogers, Teflon-based) for signals above ~1 GHz. Cell towers, radar, satellites.
• High-Tg — Boards rated for higher operating temperatures. Automotive under-hood, industrial.
• Heavy copper — 2 oz or thicker copper layers (sometimes 6 oz, 10 oz, 20 oz). Used for power electronics, motor controls, EV chargers.
• Metal-core (MCPCB / Aluminum PCB) — Aluminum or copper base instead of FR-4. Pulls heat away from components. LED lighting is the #1 use.
• Ceramic PCB — Ceramic substrate. Excellent thermal performance. Aerospace, military, very high-power applications.

By Application Volume

• Prototype / quick-turn — 1 to 50 boards, fast (24 hours to 5 days). Engineering teams testing a new design.
• Low volume / NPI (New Product Introduction) — 50 to a few thousand. Pre-production runs.
• Mid volume — Thousands to tens of thousands. Established product, ramping production.
• High volume — Hundreds of thousands to millions. Mature consumer products, automotive.

A North American shop typically thrives in prototype, low, and mid volume. High volume often goes offshore for cost.