9μm High-Precision RA Copper Foil

Base Material: High-purity electrolytic tough pitch and oxygen-free electronic grade copper (Cu purity >= 99.99%, UNS C11000 / C10200).
Crystallographic Structure: Recrystallized fine-equiaxed grain structure designed for uniform plastic deformation and high dynamic fatigue endurance.
Inclusions & Purity: Vacuum-melted and refined to minimize micro-voids, metallic inclusions, and localized stress concentrations that cause premature tearing during micro-etching or rolling. 

Dimensional Stability: Thickness tightly controlled within +/- 0.3um across the entire coil length, preventing local impedance anomalies in high-frequency transmission lines.
Flexural Endurance: Withstands over 500,000 MIT folding cycles without micro-cracking, engineered specifically for high-density dynamic flexible printed circuits (FPC).
Surface Profile: Optimized matte and shiny side roughness (Ra <= 0.4um), providing high peel strength and stable adhesion performance when laminated with polyimide (PI) films.
Thermal Resistance: Retains mechanical integrity and resists recrystallization grain growth up to 300 deg C short-term thermal exposure during multi-layer board lamination. 

Precision Rolling: Multi-high cold rolling mills integrated with Automatic Gauge Control (AGC) and laser thickness feedback loops.
Controlled Annealing: Continuous hydrogen-atmosphere and vacuum annealing lines ensuring uniform grain size distribution and zero surface carbon residue.
Online Defect Detection: 100% optical surface inspection systems running at line speeds to detect pinholes, micro-scratches, and roller marks down to 5 um.
Laboratory Verification: Every production lot is tested using universal tensile testers, laser profilometers, and four-point probe resistivity meters in our certified metallurgical lab, with random audit lots verified by independent labs such as SGS. 

Flexible Printed Circuit Boards (FPC): Signal traces for smartphone multi-layer boards, foldable OLED display hinges, and medical wearable device circuits.
Energy Storage Systems: Ultra-thin current collectors for high-density lithium-ion batteries and solid-state battery lithium-metal anode interfaces.
High-Frequency Electronics: Striplines and microstrip lines requiring low insertion loss at frequencies exceeding 10 GHz in 5G communication infrastructure.
EMC Shielding: Electromagnetic interference shielding layers for high-speed automotive radar and ADAS control modules. 

Precision Slitting: Slit widths down to 20 mm with mechanical burr height strictly controlled to <= 3 um.
Surface Passivation: Optional anti-oxidation passivation treatment or silane coupling agent application to extend shelf life and enhance resin adhesion.
Mechanical Tuning: Customized rolling reduction schedules and annealing temperature profiles tailored to specific customer stamping, bending, or battery cell winding requirements. 

Protective Structure: Suspended wooden crates lined with moisture-barrier vacuum aluminum foil bags, active silica gel desiccant, and shock-absorbing foam edge protectors.
Inert Gas Sealing: Master and slit coils are vacuum-sealed with nitrogen purging to entirely eliminate copper surface oxidation during ocean and air transit.
Full Traceability: Each master coil features a unique QR code linked to a downloadable Mill Test Certificate (MTC) detailing heat number, thickness profile charts, and tensile test data. 

Direct Mill Manufacturing: Complete in-house control from raw mother coils to final precision slitting, ensuring absolute quality accountability and stable lead times.
Rigorous Lot Consistency: Application of Statistical Process Control (SPC) across rolling reduction ratios and furnace parameters to eliminate batch-to-batch variance.
Certified Compliance: Operating under IATF 16949 and ISO 9001 manufacturing standards with a monthly output capacity of 120 metric tons.
Metallurgical Engineering Support: Direct collaboration with application engineers for technical consultation on foil selection, lamination compatibility, and thermal stress analysis.