Printed circuit board (PCB) is a component made of one or more layers of insulating material with electrical conductors. The insulator is made of various materials that are based on fiberglass, ceramics, or plastic. During manufacturing the portions of conductors that are not needed are etched off, leaving printed circuits that connect electronic components.

The main generic standard for printed circuit board design regardless of materials is IPC-2221A. This standard provides rules 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 the designer can then choose the appropriate sectional standard from the IPC-2220 series.

In the process of the routing, the conductor's width should be chosen based on selected temperature rise at rated current and acceptable impedance. The spacing between the PC traces is determined by peak working voltage, the type of the circuit and application. Depending on application, other standards may also apply. For example, for mains-powered or battery-powered information technology equipment UL 60950-1 sets additional requirements for creepage and clearance between various circuits. The minimum possible width of the traces and spacing between them are limited by the manufacturing capabilities of your vendor. Modern technology allows as low as 2 mils for both width and spacing although typical minimum values are at least 6/6 mils.

IPC and other standards do not tell you how to properly route the board. Good PCB layout techniques require understanding of the effects of non-zero trace impedance and coupling of signals from one circuit to another through parasitic capacitances and radio transmission, as well as basic understanding of circuit operation.

Here you will find guidelines for designing PCB, links to software downloads, trace calculators and other info, tools and web resources.