Your Electronics Open Source

INTRODUCTION

"A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, or traces, etched from copper sheets laminated onto a non-conductive substrate. Alternative names are printed wiring board (PWB),and etched wiring board. A PCB populated with electronic components is a printed circuit assembly (PCA), also known as a printed circuit board assembly (PCBA)." from Wikipedia Printed Circuit Board

PCB stands for Printed circuit board. In its more pure form it is simply a normally flat plastic or ceramic substrate in which alternative layers of insulators and conductors are grown sequentially to form isolated conductive paths to transfer signals and current in and out of electronic components. Sometimes the Cu traces are only in the surface of the board but most commonly the material also has internal circuitry that requires extra layers to provide conduits for power and signal flows. Multilayered PCBs are becoming fast the norm in the electronics industry as overall size decreases and number of functions goes up.

A PCB has more functions than just being a power facilitator as it provides mechanical support for the many components that are attached to it; it is the backbone of the electronic device, conforming to overall shape and dimensions, provides for signal fan out opportunities, etc. In addition and subject to distances and geometric arrangements between interactive components, it might control the electrical performance of the device t in and out of the active devices or components.

The main purposes of a PCB are:

1. Interconnect all components electrically

2. Provide mechanical support to the components mounted

3. To provide the conduit for electricity and to help dissipate heat

At this point it might be important to make a distintion between boards and packages. The first PCB type are normally associated with large form factor boards where a number of components are attached to, the most common example of these being the motherboard found in all PCs.

On the other hand, packages are smaller boards typically used as interposers or substrates for integrated circuits (IC), normally built in individual pieces of Si or chips. They help spread out the signals and provide a conduit for power to the IC. In a given PCB a number of packages can be assembled or mounted in addition to capacitors, inductors, resistors, sockets, connectors, etc. with the PCB providing the connections for those components to interact.