Rigid-flex PCBs, known as rigid-flex circuit boards, come with a rigid FR4 part and a flexible polyimide layer configured over a single assembly. This design helps to connect bendable components. With that, other components provide strong mechanical strength and connected components. Circuits help to make strong connections there. As a result, rigid-flex PCB manufacturers create boards that reduce the need for extra connectors, jacks, and cables, making electronic systems compact
In this tutorial, we will cover details about the rigid-flex PCB manufacturing process, manufacturers, and main applications.
What is a Rigid-Flex PCB
- Rigid flex boards connect flexible boards in the middle over rigid FR4 layers laminated on the upper and lower sides. A flexible core normally comes with polyimide that protects or covers the complete board size and provides bending at a selected area.
- Rigid area of FR4 laminates added structural strength for component connections and provided stability.
- Space issues solved in the aviation industry with the rigid flex process, which comes with offering high-density interconnects, flexible design, limited space, low-weight structure, and mechanical strength.
- So, the Rigid Flex Board solves these faults by providing a strong connection of rigid and flexible components without using additional interconnection hardware.
- Rigid flex board is not only employed for the aviation industry but also part of medical tools, consumer electronics, telecom sectors, the vehicle industry, defense systems, and other instruments.
Rigid-Flex PCB Manufacturing Process
- Rigid flex PCB manufacturing is performed with proper care and handling. since it’s made with a combination of different materials. accurate alignment used for lamination and making vias. The manufacturing process started with flexible core creation. After that, it was laminated with a rigid layer over it. Here, all steps are explained for manufacturing a rigid-flex PCB in detail, and working with an experienced rigid flex PCB manufacturer helps ensure quality design accuracy, reliable manufacturing quality, and long-term performance.
Overlay, prepreg, flexible laminates, & rigid laminates
- Materials like coverlay, flexible prepreg copper clad laminates, and rigid FR4 laminates are cut into accurate sizes. For rigid parts that come with exposed flex zones, copper foil is removed at specified areas. That step helps to make removal easy.
Drilling
- Holes positioned and drilled with a machine to get the required configuration. In the case of HDI designs, laser drilling is used for making microvias, through holes, and vias to make connections between layers of rigid and flex regions.
Pre-process overlay (PP) & rigid laminates
- Extra-rigid over-faces flex part follows pre-processing. That comes with controlled depth routing. These steps provide clean removal when lamination occurs.
Circuit over flex PCB
- In single-layer flexible core circuit design applied over a laminate. After that, rolled, annealed copper was etched. A multi-layer flexible core employed step-by-step lamination of copper and PI layers.
- In the case of a single-layer flexible core circuit pattern, it shifted to a laminate. After that, rolled annealed copper was etched away. The multi-layer flex core employs step-by-step lamination of copper and PI layers. circuit pattern made on every copper area
Laminate coverlay
- When circuits are created and AoI inspection is completed, coverlay laminates on the flexcore. that protect traces and provide insulation
Laminate the rigid laminates over the flex area.
- Copper and prepreg layers are added alternately and laminated over the flex core. That makes a rigid area. Proper alignment provides continuity for rigid and flex circuits.
Drill plating through holes
- PTH drilling occurs over the whole panel. For one to 2 rigid layers, the circuit achieves accuracy over external layers. In case there are more than 4 rigid layers, internal layers get a circuit pattern. after more lamination, with PTH drilling and external layer pattern
AOI, solder mask, surface finish, & silkscreen
- Finally, AOI checking is used for circuit quality and solder mask application. After that, the surface finishes and silkscreen
Removing the extra rigid areas
- Laser-controlled cutting depth routing removes extra rigid material. That shows a flex coverlay for bending. boards separated from manufacturing panels.
- After that, electrical testing is performed. That comes with power on self-test and 4 terminals sensing to be employed properly.
- Advanced features come with HDI rigid flex; the rigid part comes with heavy copper and component mounting applied over flexible locations.
Rigid-Flex PCB Applications
A rigid flex board is helpful for flexible electronic projects. that combine the bending area with strength support to components and connections. Some applications are
- Rigid flex boards make small and easy designs for VR headsets, wireless earbuds, fitness trackers, and smart clothing. Boards fold for curved enclosing.
- The vehicle industry also uses rigid flex boards, managing vibrations, high temperatures, and enclosed spaces. It works properly for control modules, sensors, ADAS systems, and braking circuits.
- Different electronic devices, such as laptops, foldable displays, and cameras, employ rigid flex for hinge locations and high-density signal routing.
- for different devices such as surgical instruments, satellite rotation systems, industrial controllers, and defense systems for bending and strong connections
Factors for selecting Rigid-flex PCB Manufacturers
Experience
- Expertise for rigid flex board manufacturers is important, since it helps provide quality rigid flex boards in the market. high experience and helps to ensure longer quality boards
PCB operation with UL 94 V-0 flame retardant rating
- For selecting a rigid flex PCB manufacturer, check that the manufacturer has the following UL94V-0 rating. These rating factors for PCBs are employed for industries and medical applications. That is preferred for where UL certifications are an important factor.
Impedance demand
- manufacturing and modeling of impedance-controlled circuits over rigid flex circuits as part of demanding projects. Both parts must be rigid and flexible. If finding a rigid flex manufacturer, check that the boards follow impedance features.
- With that check, it’s working with the supplier that’s testing boards at the manufacturing end of the process.
- Check that manufacturers have features for testing panels for providing impedance features
Fulfill manufacturing needs
- Features for fulfilling manufacturing demand are important for rigid flex PCB manufacturers. So make collaboration with manufacturers having features for offering manufacturing requirements. If not, get service for a different one
one-stop service
- When choosing a rigid flex board manufacturer, also check that it offers one-stop services. since it helps to get all PCB-related services in a single step, with reasonable prices
After-sales services
- After-sales services make the company a brand for quality services. Providing after-sales services is important. That helps users to trust manufacturers and get products again. Offering reliable after-sales features important for getting a RigidFlex PCB manufacturer.
Meet large manufacturers.
- Features for fulfilling bulk manufacturing important for getting a rigid-flex PCB manufacturer. They have the ability to make larger orders in a short time. with that made according to customer demand
Conclusion
Rigid-flex PCBs come with a mixture of rigid and flexible technologies that are compact and interconnected in difficult settings. FastTurn PCB, as a leading one-stop manufacturer and services provider, offers high-quality rigid flex projects. that provides all features, high-speed prototyping, assembly features, and low-cost manufacturing. Their expertise in turnkey PCB assembly services also helps businesses simplify manufacturing with complete design, fabrication, and assembly under one roof.
