When to Use Flex Circuit vs. Rigid Circuit Boards

Rigid circuit boards remain the most common form of Printed Circuit fabrication. However, as consumer demand for smaller devices increases, manufacturers and engineers are face with the challenge of enabling increased performance in smaller and smaller form factors to meet consumer preferences.  This continued drive to smaller, faster, cheap is a leading factor in the increased implementation of flexible circuit solutions.

Flexible circuits are ideal for medical devices, implants, sensors, and mobile consumer electronics because they fit where space and/or weight is limited. Flexible circuitry is the preferred and recommended solution for products that require:

  • Wiring solutions that fit where rigid boards cannot
  • Thin, lightweight products that are durable
  • Miniaturized versions of existing technologies
  • Three-dimensional packaging geometry
  • A low number of device interconnects
  • Shock and vibration resistance

Flex-circuits support the reduction of an application’s size and weight; and are ideal for high temperature and high-density applications.

High Temperature and High-Density Applications

Flex circuits are preferred by engineers for industrial and manufacturing applications because they are small and durable, capable of withstanding exposure to high heat and resistant to chemicals, radiation and UV exposure. Flex circuits are typically made of polyimide or a similar polymer, that dissipates heat better than the materials used to compose rigid circuit boards. The polyimide or polymer variation allows the flex-circuit to be placed in products that encounter extreme conditions without a negative impact on the product’s performance. For example, industrial sensor technologies.

Will Flex Circuits replace rigid circuit boards for all applications?

No, while flexible circuit boards are useful and grant an array of application uses, they will not replace rigid circuit boards.

The costs associated with the efficiency of implementing an exclusively flexible circuit board design in a consumer product can be high for the manufacturer, trickling down to the consumer. Rigid circuit boards are less expensive to manufacture and install (when using a standard automated high-volume fabricating facility).


A majority of innovative products incorporate flexible circuitry when necessary, and employ solid, reliable rigid circuit boards where possible to keep manufacturing and assembly costs down.

Some manufacturers, like Green Circuits use hybrid rigid-flex printed circuit boards, rigid circuit boards connected to one other using ribbon-like flexible circuits, for product manufacturers. Rigid-flex boards can be compounded and designed to meet any number of engineering needs by focusing on the respective strengths of each circuit board base technology. These boards are commonly used in the manufacturing medical devices and other high reliability products.


About Green Circuits: An Experienced Electronic Manufacturing Service (EMS) Provider

Green Circuits is an experienced ITAR, ISO 13485 and AS-9100 Certified electronics manufacturer, specializing in quick-turn PCB prototype design, assembly, inspection, and rework. Green’s experts ensure product reliability and accuracy by performing thorough inspections and tests, using state-of-the-art equipment in our ESD-controlled facility, procuring premium quality components, a thorough understanding of Industry Standards and custom manufacturing requirements, and actively communicating with all product-involved teams throughout the manufacturing process.

Green Circuits enables firms of all sizes to improve their production cycle while reducing manufacturing time and costs by providing an array of turnkey PCB assembly and manufacturing services to meet the needs and requirements of all production sizes.