How are PCBs made?

How is a circuit board made?

PCB manufacturing is one of the key stages in a full suite of PCB production services. It typically follows the initial circuit design, prototyping, and assembly phases.

Today’s state-of-the-art PCBs are manufactured using precision techniques and advanced materials. They’re produced using a combination of manual and mechanical processes, resulting in a board of optimal quality.

When manufactured with skill, accuracy, and expertise, the finished board will function precisely as intended, and be durable enough to meet the demands of its role over an extended period. Whatever the individual use case may be, a well-made PCB must of course remain a reliable and consistent performer throughout its functional lifetime.

In this short guide, we’ll answer the common question ‘How are printed circuit boards made?’ by looking more closely at some of the specific manufacturing techniques we use here at ABL Circuits.

PCB parts and materials

The basic construction of a standard modern PCB involves several core components. The most familiar of these will probably be the physical board substrate itself.

This is usually made in a sandwich structure consisting of two or more layers, with conductive copper sheets separated by some form of rigid or semi-rigid insulating (non-conductive) material. These substrate layers form the board’s ‘core’, and are responsible for the majority of its weight and structural integrity.

One material commonly chosen for non-conductive or dielectric layers is fibreglass, which helps to give the finished PCB a good degree of rigidness and durability. If your specific application requires a more flexible construction, then other types of PCB manufacturing processes are available. These layers form the ‘core’ of the board, and their role is both structural and insulating. Discover more about what a circuit board is made of.

Conductive and masking layers

Thin sheets of copper foil are usually chosen for the conductive layers. These are laminated to one or both sides (depending on the PCB design) of the substrate under high pressures and temperatures, using a special adhesive.

The connecting pathways that carry electrical current around various components mounted on a finished PCB are known as traces. These traces are etched into the copper layer, taking advantage of the material’s high electrical conductivity to form a complete circuit. It’s therefore extremely important that the copper layers are well insulated, to prevent unwanted contacts from interrupting or shorting the circuit at any point.

Depending on the construction and circuit requirements of the PCB, this insulation is provided either by an additional layer(s) of substrate material or by using a solder mask on the outermost faces of the board. Solder masks will often have detailed information printed on them, outlining the intended layout of the circuitry and attached PCB components. For a more detailed look at this layering process, see our dedicated pages on PCB Layers Explained, PCB Assembly, and the PCB Manufacturing Process.