PCB Design

PCB is an acronym for printed circuit board. It is made of one or several layers of insulating material and is used to physically support and electrically connect electronic components. PCBs are used in virtually every commercially produced electronic device.

Design of PCBs may involve projects ranging from single transistors up to highly sophisticated electronic systems. Larger systems are designed via a systematic approach by teams of specialists with the help of intelligent computer software.

Presently the basic standard for the PCB design is IPC-2221A. It specifies guidelines for manufacturability and quality such as requirements for material properties, criteria for surface plating, conductor thickness, component placement, dimensioning and tolerance rules, and more. For a specific technology, a designer can then choose an appropriate sectional standard from the IPC-2220 series.

This and other standards, however, do not specify how to properly route the board. With the process of PCB design we move from the specification at the start to a detailed plan that includes all the information needed to mechanically construct the circuit board at the end.

The PCB Design process usually starts with the transforming the specification into a diagram of the numerous tasks that the circuit will perform, which is sometimes referred to as a black box design. This method allows breaking sometimes a very complex task into smaller tasks that may either be tackled one after another or split amongst members of a design team.

After this each block is considered in more detail. This and / or later stages often require a considerable amount of research or mathematical modeling to be done to determine whether the plan is realistic or not.

At this stage of PCB design it is sometimes necessary to return to the earlier steps with the results of the research, if, for example, it is determined, that one of the blocks cannot be designed within the determined parameters. If this happens, it is often the other blocks that are altered as well.

Next, the specific electronic components are picked up to perform each function in the overall design. The physical layout as well as electrical connections of each individual component is also decided at this point. Critical routes are traced manually.

Most PCB design software packages have good design rule checkers. Using them may save you hours, if not days, of work time. Once again, the PCB design is crucial for proper operation of power electronic devices.