Since 2008, Ring PCB has been a trusted manufacturer of rigid-flex PCBs at our Shenzhen factory. With years of experience, we are committed to delivering durable and reliable rigid-flex PCBs. 

What Are Rigid-flex PCBs?

Rigid-flex PCBs are specialized printed circuit boards that combine rigid and flexible layers in a single structure, allowing for both sturdy support and flexible areas where needed. The rigid sections provide stability for mounting components, while the flexible sections enable the board to bend and conform to tight or complex spaces within devices. These boards combine the benefits of both rigid and flexible PCBs, making them ideal for applications requiring both stability and flexibility in a single unit that need to be lightweight and compact.

Structure of Rigid-flex PCB

Rigid Layers: These sections use traditional rigid PCB materials, typically FR4, to provide structural stability and support for mounting components. They are generally located in areas of the PCB that will not bend, offering a solid foundation for high-density component placement.

 

Flexible Layers: Made from flexible materials like polyimide, these layers connect the rigid sections and allow the board to bend or twist as needed. The flexible layers are typically thinner than rigid ones and may have a coverlay to protect the circuits in the flexible area from damage.

 

Conductive Layers: Copper is the most commonly used material for the conductive layers, forming the circuit traces and interconnections. These copper layers run through both the rigid and flexible parts, connecting components and allowing electrical signals to flow across the board.

 

Adhesive Layers and Bonding Films: Adhesive or bonding films are often used between rigid and flexible layers to ensure a strong bond and maintain the integrity of the board structure during flexing.

 

Coverlay on Flex Layers: A protective film called coverlay (typically polyimide) is used over the flexible circuits to protect the copper traces in areas where solder masks cannot be applied due to the need for flexibility. Coverlay helps to shield the copper from environmental factors, mechanical stress, and wear.

 

Via Types: Rigid-flex PCBs often include a mix of through-hole, blind, and buried vias to connect layers. Through-hole vias pass through both rigid and flexible layers, while blind and buried vias are used to connect specific layers without passing through the entire board.

 

Stiffeners (Optional): In areas where additional rigidity is needed within the flexible sections, stiffeners made from materials like polyimide or FR4 are sometimes added. These provide localized support without affecting the overall flexibility of the design.

 

Surface Treatments: Surface finishes like ENIG (Electroless Nickel Immersion Gold) or OSP (Organic Solderability Preservative) are often applied to protect the copper on component pads and improve solderability during assembly.

Applications of Rigid-Flex PCBs 

Rigid-flex PCBs are essential in high-end applications that demand both durability and compact design. In medical devices, they allow compact, reliable designs for diagnostic tools and wearable health monitors. Aerospace and defense systems use rigid-flex boards for avionics, navigation, and communication equipment due to their resistance to vibration and harsh environments. In consumer electronics, they are vital for slim, portable devices like smartphones and wearables. Automotive applications include sensors and infotainment systems, where reliability and the ability to fit in confined spaces are crucial.

Why Choose Ring PCB?

Advanced Manufacturing Processes

At our Shenzhen facility, Ring PCB utilizes specialized equipment and manufacturing processes to produce rigid-flex PCBs with precision. Key processes include:

• Lamination and Bonding: Combining rigid and flexible layers requires careful lamination to prevent warping or misalignment. We use advanced lamination techniques to create a seamless bond between layers.

• Laser Drilling and Routing: For precise hole and via formation, we use laser drilling, which allows for higher accuracy, particularly in compact designs with small vias.

• Controlled Impedance: We implement precise impedance control techniques for designs that require high-frequency signal integrity, ensuring that the PCB performs optimally in its final application.

• Surface Finishing: To enhance durability and reliability, we offer various surface finishes, including ENIG (Electroless Nickel Immersion Gold), HASL (Hot Air Solder Leveling), and Immersion Silver.

Quality Control and Testing Procedures

• Automated Optical Inspection (AOI): AOI enables us to detect surface defects and misalignments, ensuring that each PCB is produced to the exact design specifications.

• Electrical Testing: We perform continuity and insulation tests to confirm that the circuit connections are functioning correctly.

• Flexibility and Bend Testing: To guarantee that the flexible sections of each board meet durability standards, we conduct flexibility and bend testing under simulated operating conditions.

• Thermal Cycling: This test simulates temperature variations to ensure that the PCB can withstand harsh environments without performance degradation.