Why Flexible Printed Circuit Boards are Perfect for High Frequency Applications

The demand of printed circuit boards in applications comprising high frequency and speeds is substantially increasing. The reason behind this is the increase in bandwidth requirements as well as miniaturization of devices. To ensure complete application success, it is necessary that the right type of circuit board is used. Flexible printed circuit boards have been found to be the best option among the three printed circuit board types for high performance applications.

The Advantage of Flexible PCB Materials

There are a number of factors that make flexible printed circuit boards perfect for high frequency applications:

    • Flex Materials: While this may seem like an obvious point, it is nonetheless an important one. High frequency applications require consistent thin film circuit layers. Various types of flexible polymer films are used to create the circuits. The films ensure that thin and consistent flexible layers are created, which makes them the best choice for high frequency applications.
    • Copper: The type of copper used in the manufacturing process of flexible printed circuit boards is significantly different from the copper material used in rigid circuit boards. Copper used to manufacture flexible printed circuit boards is made from running a large ingot through a series of rolls. The rolling process also makes the copper ductile and anneals it to create large copper grains. The large grain size makes it more durable in an application. Also, copper is attached to the flex material using adhesives rather than soldering, which can break easily.
    • Dielectrics: This is a type of laminated resin, which comprises good insulation and conduction capacity. Dielectrics comprise ceramic filler, which acts as an adhesive and bonds with the copper foil of the flexible circuit board. Flexible printed circuit boards are usually constructed with epoxy or acrylic adhesives. Both rank high in terms of relative permittivity at frequencies above 1 GHz. That is why flex materials are used for high frequency applications as they comprise high dielectric thickness.

The above reasons prove that flexible printed circuit boards are the best type of circuit board for high frequency applications.