35μm High-Precision RA Copper Foil

Base Metal: High-purity electrolytic copper (Cu >= 99.99%, UNS C11000 / C10200).
Metallurgical State: Fully annealed (O temper) with a uniform equiaxed grain structure maximizing elongation and fatigue resistance under cyclic bending.
Inclusion Control: Vacuum induction melting minimizes oxygen and trace metallic impurities, preventing pinholes and micro-cracks during rolling reductions. 

Thickness Consistency: Controlled within +/- 0.8um transversely and longitudinally, ensuring predictable electrical resistance and etching behavior.
Elongation Rate: Longitudinal elongation exceeds 25%, accommodating tight dynamic bending radii in dynamic FPC applications.
Surface Profile: Low-profile matte and shiny sides optimized for fine-line circuit etching (<= 20um pitch).
Tensile Strength: Maintained between 250 to 320 MPa, balancing mechanical robustness with structural flexibility. 

Precision Rolling: Multi-high rolling mills equipped with automatic gauge control (AGC) regulate thickness in real time.

Controlled Annealing: Hydrogen-nitrogen mixed atmosphere annealing lines eliminate oxidation and hydrogen embrittlement.

Inline Inspection: 100% surface optical defect inspection systems detect pinholes, scratches, and edge cracks during slitting.

Laboratory Verification: Every lot undergoes tensile testing, atomic absorption spectroscopy (AAS) for chemical purity, and atomic force microscopy (AFM) for surface topography verification.

Quality Systems: Manufactured under ISO 9001 and IATF 16949 certified quality management protocols, ensuring strict lot-to-lot traceability.

Flexible Printed Circuit Boards (FPCs): Conductor layers for multilayer dynamic FPCs in aerospace and consumer electronics.
Lithium-Ion Battery Current Collectors: Specialized current collectors for high-power pouch and cylindrical cells requiring high vibration resistance.
Electromagnetic Interference (EMI) Shielding: Tape and wrap configurations for high-frequency coaxial cables and medical diagnostic equipment.
Transformer Windings: Low-loss foil conductors for miniature high-frequency transformers. 

Slitting Tolerances: Slitting width accuracy maintained at +/- 0.1 mm with burr-free edges.
Surface Treatments: Options include anti-tarnish passivation, chemical roughening, or bonding-promotion coatings tailored to specific resin systems (polyimide, PET, or epoxy).
Core Diameters: Available on 3-inch or 6-inch plastic/aluminum cores based on automatic unwinding equipment requirements.
Roll Lengths: Continuous splice-free coil lengths up to 3000 meters depending on width specifications. 

Moisture Protection: Vacuum-sealed in anti-static, multi-layer aluminum foil bags with active desiccant packs.
Physical Cushioning: Suspended in heavy-duty wooden crates using shock-absorbing edge protectors to eliminate transit deformation and telescope effects.
Traceability: Each master coil and slit roll features a unique QR/bar code detailing heat number, exact thickness profile, test data, and manufacturing timestamp. 

Direct Mill Production: In-house metallurgical processing from melting to final slitting ensures absolute control over material properties without intermediary variance.

Lot Consistency: Statistical process control (SPC) charts provided upon request for critical automotive and aerospace contracts.

Technical Support: Direct access to materials engineers to assist with alloy selection, corrosion evaluation, and etching parameter optimization.