Getting to Know the Printed Circuit Board

The concept of a circuit board prototype is pretty simple Circuit board prototyping is an easy way to test printed circuit boards without wasting money on a full production run. An effective prototype board is one designed to the most exact specifications.

Quick turn PCB prototypes will save you time and money in the long run as you develop a PCB fit for a full production run. Quick turn PCB prototypes provides manufacturers with a solution to the need for a quickly produced prototype with customized features.

If you’re considering testing a quick turn PCB prototype, be sure to reacquaint yourself with the basics of PCBs.

Getting to know the Printed Circuit Board

There are two types of circuit assemblies related to printed circuit boards (PCBs): an integrated circuit–sometimes referred to as an IC or microchip–and a hybrid circuit (also called a hybrid integrated circuit or HIC. While both circuit assemblies serve the same purpose, the differences between integrated circuits and hybrid circuits lie in their construction and manufacturing. Hybrid circuits can use certain components–inductors, crystals, capicitors of large value–which are not able to be included with integrated circuits. Hybrid circuits are often encapsulated in epoxy.

Like hybrid circuits, PCBs are often insulated in epoxy; specifically, FR-4 glass epoxy is the primary insulating substrate for the overwhelming majority of rigid PCBs. On one or both sides of an FR-4 panel is a laminated layer of copper foil. Etched into the copper layers are circuitry interconnections for the productions of printed circuit boards. With multiple layers, complex circuits are produced.

By curing under pressure and temperature layers of paper or cloth with thermoset resin to create a uniform thickness, laminates are manufactured. When the cloth/paper resin combines with the resin, a laminate is formed. A laminate can be up 4 by 8 feet (1.2 by 2.4 m) in size.

On one or both sides of the PCB, a legend is printed. The legend consists of the component designators, test points, switch settings and other indicators which are useful in putting together, testing and servicing the circuit board. There exist three different methods for printing the legend: ink jet printing, liquid photo imaging, and silk screen printing.’

If you’re planning on using a quick turn PCB prototype or just want to re-familiarize yourself with the concept, this article is a good refresher.