At Redstar Worldwide, we maintain experienced design and engineering teams who possess a thorough understanding of printed circuit board (PCB) technologies, including how they perform and how to implement features that suit our customers’ needs. As an international and domestic PCB supplier, we source high-quality PCB products from reputable manufacturers, including flexible PCBs.

Flex PCB Fabrication

Flexible printed circuit boards are available with a wide range of design options to suit different applications. Some of the elements that may vary from one PCB design to the next are:

  • Base material
  • Copper type: rolled vs. annealed
  • Core type: with adhesives vs. without adhesives
  • Circuitry protection: coverlay vs. soldermask
  • Flex: static vs. dynamic
  • Coatings: e.g., ENEPIG, EPIG, and ENEG

At Redstar Worldwide, we offer the following PCB design tolerances:

  • Trace/space tolerance: +/- 10%
  • Drill position tolerance: +/- 0.4 mil
  • Drill size tolerance: +/- 10%
  • Impedance control: +/- 5%
  • Flex-to-rigid registration: +/- 3 mil

We also provide testing and inspection services, including 100% electrical testing, inspection reporting, and providing certificates of conformity, to verify that every flex PCB we deliver meets the required specifications and standards.

Flex PCB Design Rules

Flexible printed circuit boards—also referred to as flex PCBs—utilize a flexible substrate, such as polyimide. The use of a flexible base material allows for greater functionality and spatial efficiency in limited-space applications. Depending on the requirements and restrictions of the use case, Redstar can employ a single, double, or multilayer flex PCB design.

When designing a flex PCB, it is critical to prepare proper documentation for the PCB manufacturer. Some of the design rules to take note of include:

  • Avoiding bends at corners and keep the flex PCB bend radius in mind
  • Ensuring bends have a gentle, rather than sharp, curve
  • Maintaining a gradual change in the width of traces
  • Keeping the number of flex layers employing to a minimum


In addition to coordinating the manufacture of flexible PCBs with overseas companies, Redstar Worldwide provides design and engineering assistance. For every design project we take on, our experts work to keep the design within known manufacturing capabilities and ensure it meets customer specifications and all applicable industry standards, including ISO 9001, ISO 13485, NADCAP, ASTM, and UL.

Benefits of Flex PCBs

Compared to traditional circuit boards and rigid PCB, flexible PCBs offer several benefits, including:

  • Lower part count
  • Smaller board size, weight, and space requirements
  • Better connection reliability due to having fewer solder joints
  • Broader design options
  • Greater suitability for high-density applications
  • Simpler assembly and testing requirements


However, depending on your needs, a rigid-flex or rigid PCB may be a better option. Redstar is able to assess your flex circuit technology needs and advise on the correct type of PCB.

Applications of Flex PCBs

Flexible PCBs find use in a variety of electronic applications, including in the following:

  • Automobiles
  • Cell phones
  • Digital cameras
  • Green and solar energy systems
  • IoT systems
  • Medical equipment
  • Military and defense equipment
  • Server communications
  • Smart glass
  • Testing equipment
  • Tools
  • Unmanned aircraft
  • Weapon control systems
  • Wearable technology and biometric devices

Flex PCB Prototyping From Redstar Worldwide

We offer quick-turn prototyping to help customers test and evaluate the flex circuit prototype before proceeding to full-scale production. Within two hours of receiving a design, our 24/7 support team performs a manufacturability review to identify potential problems and communicate solutions to the client. Once the design is approved for prototyping, they can turnaround high-quality prototypes fabricated to strict SOPs in as little as 24 hours.

Why Turn to Redstar Worldwide for Flex PCBs?

At Redstar Worldwide, we provide our customers with flex PCBs ranging from simple to highly complex. By partnering with us for their PCB needs, our customers benefit from our:

  • Decades of experience with simple to complex PCB builds
  • Quick turn flex PCB design with fast turnaround
  • Comprehensive engineering services, including design, inspection, and RoHS consulting
  • Relationships with overseas suppliers
  • Superior quality and competitive prices

Our engineering capabilities, combined with our partnerships with overseas and domestic manufacturers, allows us to deliver high-quality flexible PCBs suitable for a diverse set of industries, including audio/video, automotive, consumer products, EMS, and wearable technology. Contact our team to learn more about our services or request a flex PCB online quote to get your order started today.