Copper clad laminate is a fundamental material in electronics manufacturing, specifically in the production of printed circuit boards (PCBs). While it is not a domestic building or home improvement material, it appears in search queries from electronics hobbyists, engineers, and those building or repairing electronic equipment for home workshops and mancave projects.

What It Is

Copper clad laminate consists of a rigid or flexible insulating substrate, most commonly glass-reinforced epoxy resin known as FR4, bonded on one or both sides with a thin layer of electrolytic copper foil, typically between 17.5 and 70 micrometres thick. The substrate provides the structural and insulating base; the copper layer is the conductive material that is selectively etched away to form the circuit traces of a PCB.

Common Substrate Types

FR4 is the most widely used PCB substrate material, consisting of woven fibreglass cloth impregnated with epoxy resin. It offers good mechanical strength, dimensional stability, and adequate electrical insulating properties for most digital and analogue circuit applications. Other substrate types include CEM-1, a cheaper composite material used in single-sided boards for simple consumer electronics, high-frequency substrates using PTFE or ceramic for RF and microwave applications, and flexible polyimide substrates for flexible PCBs used in wearable electronics and compact devices.

Single-Sided and Double-Sided

Single-sided copper clad laminate has copper on one face only and is used for simple single-layer PCBs. Double-sided has copper on both faces and is used for two-layer circuits where connections need to pass from one side of the board to the other through plated-through holes. Most modern PCBs are multi-layer constructions with copper on multiple internal and external layers, though hobbyist PCB fabrication typically uses single or double-sided material.

DIY PCB Making

Copper clad laminate is available from electronics component suppliers and is used by hobbyists to fabricate their own PCBs using chemical etching or CNC milling. The most common hobbyist method involves printing a circuit design onto transfer paper, ironing the toner onto the copper surface, and then etching away the exposed copper with ferric chloride or similar etchant solution to leave only the desired copper circuit traces.

Summary

Copper clad laminate is a fibreglass or resin substrate coated with copper foil, used as the base material for printed circuit boards. FR4 is the most common substrate type. Single-sided and double-sided variants are used for different circuit complexities. Hobbyists use it with chemical etching or CNC milling to fabricate custom PCBs. Ferric chloride etchant is hazardous and requires safe handling and responsible disposal.