Flexible vs. rigid circuits: how to choose them for your industrial application

Advantages and challenges of flexible circuits versus rigid circuits

This overview begins by comparing their main attributes and characteristics. These are the key qualities of these products:

• Weight. Rigid circuits use thicker substrates, such as FR4, and therefore weigh more. Flexible circuits are much lighter and, consequently, are better suited for drones, laptops, and similar devices.
• Space/Design. Flexible circuits save space and allow for 3D designs, thus helping to eliminate connectors and cables.
• Durability and Strength. Rigid circuits offer high mechanical strength in installations and, in general, under high currents and high temperatures. Flexible circuits (FPCs) withstand these same vibrations well and fail less frequently in applications involving continuous motion.
• Reliability. Rigid circuits are more reliable in static environments, while flexible circuits are more reliable in motion.
• Airflow/Cooling. Depending on the design, airflow can be obstructed in rigid circuits, while heat dissipation is generally better in flexible circuits.

Among the challenges of flexible circuits, however, cost stands out, as the use of polyimide and its more complex and precise manufacturing processes increase their price. Likewise, their production and assembly are more intricate and complex than those of rigid circuits.

Furthermore, their greater fragility requires extreme care during handling and assembly, while their thinness results in a lower current-carrying capacity.