Ultra-High Purity Stainless Steel Coil Tube — SEMI F19 Semiconductor Grade
Product Overview
The Ultra-High Purity Stainless Steel Coil Tube is engineered to comply with the SEMI F19 standard (Standard for Ultra-High Purity Stainless Steel Tubing), which is governed by the Semiconductor Equipment and Materials International (SEMI) organization. This product is specifically designed for semiconductor fabrication environments where particulate contamination, metallic outgassing, and surface integrity are critical process variables. Manufactured by Wenzhou Jixing Metal Materials Co., Ltd., this coil tube represents the highest tier of purity classification in the semiconductor-grade tubing industry.
Material & Properties
The base material is Alloy 60 (UNS S31254) or Alloy 600 (UNS N06600), selected for their exceptional resistance to corrosion, low particulate generation, and minimal metallic contamination release under vacuum and high-temperature process conditions.
- Material Purity: Metallurgical analysis ensures trace elemental content is maintained below SEMI F19 thresholds — typically < 0.001% for carbon (C), < 0.015% for sulfur (S), and < 0.030% for phosphorus (P).
- Electropolished (EP) Surface Finish: The interior and exterior surfaces are processed to achieve a surface roughness of Ra ≤ 0.15 μm (6 μin), minimizing particle adhesion and facilitating cleanroom-compatible wet or dry cleaning protocols.
- Surface Passivation: Post-polishing passivation using nitric acid (HNO₃) or citric acid (C₂H₆O₇) solutions to form a stable, protective chromium oxide layer that inhibits corrosion and reduces metallic ion leaching.
- Coil Form Factor: Supplied in continuous coil configuration, enabling seamless integration into automated tube-forming, bending, and fabrication lines without introducing weld seams or additional contamination points.
Specifications
| Parameter | Specification | Standard Reference |
|---|---|---|
| Applicable Standard | SEMI F19 (Ultra-High Purity Stainless Steel Tubing) | SEMI F19-0201 |
| Material Grade | Alloy 60 (UNS S31254) / Alloy 600 (UNS N06600) | ASTM B366 / ASTM B167 |
| Surface Finish (ID/OD) | Electropolished, Ra ≤ 0.15 μm (6 μin) | SEMI F19, Section 4 |
| Wall Thickness | 0.5 mm – 3.0 mm (customizable) | ASME B36.19M |
| Outer Diameter | 3.175 mm (1/8") – 31.75 mm (1-1/4") | ASME B36.19M |
| Coil Length | 10 m – 100 m per coil (configurable) | Manufacturer Specification |
| Packaging | Multi-layer clean packaging: inner polyethylene (PE) film + outer aluminum foil + cleanroom-grade outer carton | SEMI F19, Section 7 |
| Particle Contamination | ≤ 1 particle ≥ 0.5 μm per 100 mm tube length (post-cleaning) | SEMI F19, Section 6 |
| Outgassing Rate | ≤ 1 × 10⁻⁸ Torr·L/s·cm² (at 150°C, after bake-out) | SEMI F19, Section 5 |
| Weld Seam | Continuous coil — no longitudinal weld seam | — |
Manufacturing Process
The production of SEMI F19–compliant coil tube follows a rigorously controlled, end-to-end process chain designed to eliminate contamination at every stage:
- Material Selection & Ingot Casting: Ultra-pure raw stock is sourced from certified smelters with full traceability. Ingot composition is verified via inductively coupled plasma (ICP) spectroscopy to confirm trace element compliance.
- Hot Rolling & Cold Drawing: The material is hot-rolled into seamless tube blank, then cold-drawn through precision dies to achieve target dimensions with tight tolerances (±0.05 mm on wall thickness).
- Pickle & Passivation: The drawn tube undergoes acid pickling to remove surface oxides and scale, followed by chemical passivation to restore the protective chromium oxide passive layer.
- Electropolishing (EP): Electrochemical polishing is performed in a controlled fluoride-chromate bath to achieve the required Ra ≤ 0.15 μm surface finish on both interior and exterior surfaces. This step removes the micro-scale work-hardened layer and embedded particles.
- Wet Cleaning: Multi-stage cleaning using ultra-pure water (UPW, 18.2 MΩ·cm resistivity), followed by solvent rinse and final UPW rinse, conducted in a cleanroom environment (ISO Class 7 minimum).
- Dry & Inspection: The cleaned tube is dried under vacuum or with high-purity nitrogen. Surface integrity is inspected via borescope and particle counter. Dimensional verification is performed using laser micrometry.
- Clean Packaging: The tube is immediately sealed in multi-layer protective packaging within a cleanroom to prevent re-contamination. Each coil is serialized and accompanied by a full traceability data package.
Applications
SEMI F19-grade coil tube is deployed in the most demanding environments within semiconductor manufacturing and adjacent high-purity industries:
- Chemical Mechanical Planarization (CMP) Fluid Delivery: Transport of ultra-pure chemical slurries and process fluids in wafer fabrication facilities.
- Gas Delivery Systems (GDS): High-purity gas lines for CVD (Chemical Vapor Deposition), PVD (Physical Vapor Deposition), and etching processes where particulate contamination can cause wafer defects.
- Ultra-Pure Water (UPW) Distribution: Piping for water purification and distribution systems supplying critical process water to lithography, cleaning, and rinse stations.
- Vacuum System Components: Feedthroughs and internal tubing for vacuum chambers requiring ultra-low outgassing rates.
- Photolithography Equipment: Fluid and gas lines in stepper/scanner tools where even sub-micron particles can compromise pattern fidelity.
- Display Panel & Solar Cell Manufacturing: High-purity process lines in flat-panel display and photovoltaic production facilities.
Quality Certifications & Compliance
Every coil of SEMI F19–compliant stainless steel tube from Wenzhou Jixing Metal Materials Co., Ltd. is backed by a comprehensive quality assurance framework:
- SEMI F19 Certification: Full compliance with the SEMI F19 standard for ultra-high purity stainless steel tubing, including material purity, surface finish, particle count, and packaging requirements.
- ISO 9001:2015: Quality Management System certification ensuring consistent process control and continuous improvement across all production stages.
- ISO 14001:2015: Environmental Management System certification for sustainable and responsible manufacturing practices.
- Mill Test Reports (MTR): Each batch is accompanied by a full material test report including chemical composition (ICP-OES analysis), mechanical properties (tensile strength, yield strength, elongation), and heat treatment records.
- Surface Finish Verification: Independent third-party Ra measurement certification from accredited laboratories.
- Particle Count Certification: Post-cleaning particle count data reported per SEMI F19 Section 6 methodology.
- Full Traceability: Each coil is serialized with a unique identifier linking it to its material lot, heat number, production date, and complete inspection history.
Unique Selling Points
End-to-End Cleanroom Processing: From electropolishing through final packaging, all critical operations are performed in ISO Class 7 or better cleanroom environments, eliminating the risk of cross-contamination between processing stages.
Seamless Coil Configuration: The continuous coil format eliminates longitudinal weld seams entirely, reducing potential contamination pathways and enabling flexible downstream fabrication without introducing additional joints.
Full Traceability Data Package: Every coil ships with a comprehensive documentation package including MTR, surface finish reports, particle count data, and outgassing test results — providing semiconductor OEMs with the complete audit trail required for qualification and qualification maintenance.
Customizable Specifications: Diameter, wall thickness, coil length, and packaging configurations can be tailored to meet specific customer design requirements while maintaining full SEMI F19 compliance.