PCB design plays a core role in manufacturing a printed circuit board. The layout process produces a graphical representation of the circuitry necessary to manufacture a PCB. PCB design is a detailed description and visual representation of the circuit. Most of the circuit boards manufactured today are assembled and tested by automated machines, driven in part by the data provided by the PCB files. In this light, the need for a PCB layout becomes evident.
With the development of CAD tools by several different companies, it is now common for the PCB layout to be prepared using CAD software tools. These computer-based programs offer tools and techniques to effectively and efficiently design a PCB and generate the necessary files to manufacture the board.
Design for manufacturability has become an increasingly necessary part of the PCB design process. Designers must take into consideration the manufacturing process when designing a board. This requires designers to understand the manufacturing process and how layout affects that process.
The PCB design should consider current flow, size of the circuit, and electromagnetic interference to specify track width. Also, impedance, signal tracks, and susceptibility need to be measured for a particular circuit to prepare the precise PCB design. The components' positioning, alignment, and relationship with each other also have to be thoroughly described in the layout.
Through CAD software, it is possible to prepare a multi-layer design. To maintain visibility, the actual display of different layers is done in separate colors while they are merged into an overlay image.