Flex Circuits (PCB): Introduction, Advantages, Design

Flex circuits (Flex PCB, flexible circuits, flexible printed circuit boards, flex print,, also known as flexi-circuits) are members of the electronics and interconnect family. They consist of a thin insulating polymer film on which a conductive circuit pattern is fixed, and a thin polymer coating is usually provided to protect the conductive circuit. Since the 1950s, the technology has been used to interconnect one or more forms of electronic devices. It is one of the most important Interconnection Technologies for manufacturing many of today’s most advanced electronic products.

In fact, there are many different kinds of flex circuits, including one metal layer, two-sided, multi-layered and rigid flexible circuits. These circuits can be formed by etching a metal foil coating (usually copper) from a polymer substrate, electroplating metal, or printing conductive ink. Flexible circuits may or may not connect components. When the components are installed, some people in the industry think they are flexible electronic components.

The main advantages of flex circuits include:

• Reduce wiring errors
• Elimination of mechanical connectors
• Unparalleled design flexibility
• Higher circuit density
• More stable operating temperature range
• Better signal quality
• Improved reliability and impedance control
• Size and weight reduction

Flex circuit design may require any of the following:

• Highly complex configuration
• Withstand harsh operating environment
• Single and double combination
• Complex interconnection
• Shielding layer
• Rigidity / flexibility
• Surface mount equipment