4 Layer Blue Oil Rigid Flex PCB Soft Hard Bonding Customized Printed Circuit Board

4-layer blue oil soft hard bonding board PCB

  This 4-layer flex-rigid PCB, featuring a striking blue solder mask, combines exceptional performance with unparalleled design versatility. It's the perfect solution for space-constrained, high-reliability electronic applications that demand both durability and flexibility.Structurally, the PCB showcases a meticulously engineered 4-layer architecture. The rigid sections, constructed from high-quality FR-4 material, offer robust mechanical stability, ensuring durability under various operating conditions. Meanwhile, the flexible segments are crafted from premium polyimide (PI) film, providing outstanding bendability and enabling effortless 3D integration within compact, space-constrained environments. The blue solder mask coating not only delivers excellent insulation and chemical resistance but also offers high-contrast visibility, streamlining the inspection process during both manufacturing and field maintenance for enhanced quality control.

Core Characteristics

• Structural Versatility: Integrate rigid sections for component mounting and flexible segments for bending, folding or twisting. They adapt to compact or irregular device spaces without compromising connection stability.
• Reliable Connectivity: Eliminate the need for connectors or wires between rigid parts, reducing assembly errors and failure risks. The integrated structure ensures consistent signal transmission even in dynamic environments.
• Space & Weight Optimization: Replace bulky rigid PCB assemblies with streamlined designs. They save up to 50% of installation space and reduce overall device weight, ideal for portable or miniaturized products.
• Enhanced Durability: Flexible layers resist vibration, shock and repeated bending, extending product lifespan. Rigid areas provide robust support for heavy components like chips or capacitors.
• Improved Signal Integrity: Minimize signal loss and electromagnetic interference (EMI) through shortened interconnections. The design maintains signal stability in high-frequency or high-speed applications.

Manufacturing process:

• Design & Material Specification:The design phase requires clear delineation of rigid and flexible zones, paired with selection of appropriate substrate materials (e.g., FR4 for rigidity, polyimide for flexibility) and compatible processes to ensure seamless integration of both segments.
• PCB Lamination: Fabrication of flex-rigid structures involves precision lamination of rigid and flexible layers, typically via controlled hot pressing and adhesive bonding, to consolidate multi-material circuit layers into a unified board.
• Etching & Drilling: Post-lamination, the substrate undergoes photolithographic patterning and chemical etching to form precise circuit traces. Subsequent drilling (including microvias) enables component mounting and interlayer electrical connectivity.
• Surface Finishing: Protective surface treatments—such as gold plating, tinning, or organic solderability preservatives (OSP)—are applied to enhance solderability, prevent oxidation, and ensure long-term environmental resilience.
• Assembly & Validation: Post-fabrication, the board undergoes component placement (SMT or through-hole) and soldering, followed by rigorous electrical testing to verify functional performance and compliance with design specifications.