Stainless Steel Coil Tube — Ion Chromatography (IC) Cleanliness Verification System
Product Overview
The Stainless Steel Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd is engineered to meet the most stringent cleanliness requirements demanded by semiconductor manufacturing, ultra-pure fluid delivery, and high-purity chemical processing industries. This product undergoes rigorous Ion Chromatography (IC) testing to independently quantify both anionic and cationic contamination at parts-per-billion (ppb) levels, ensuring that metal ion leaching is controlled to levels that prevent wafer contamination and process failure.
The Coil Tube is supplied in continuous coil form, enabling high-speed, low-stress processing and fabrication into precision tubing assemblies for critical applications where even trace elemental contamination can compromise yield and device performance.
Material & Properties
The Coil Tube is fabricated from high-purity austenitic stainless steel grades, predominantly conforming to ASTM A269 / ASME SA-269 specifications. The material composition is meticulously controlled to minimize residual elements that contribute to ionic leaching under aggressive cleaning and operating conditions.
- Base Alloy: 304L (UNS S30403), 316L (UNS S31603), or custom ultra-low-carbon variants
- Carbon Content: ≤ 0.030% (low-carbon grade to prevent sensitization and pitting)
- Chromium (Cr): 18.0–20.0% (passive oxide film integrity)
- Nickel (Ni): 8.0–12.0% (corrosion resistance and formability)
- Molybdenum (Mo): 2.0–3.0% (enhanced pitting resistance, 316L grade)
- Sulfur (S): ≤ 0.015% (reduced inclusion-driven contamination)
- Surface Finish: Electro-polished or passivated to achieve Ra ≤ 0.25 μm
- Operating Temperature Range: −196 °C to +450 °C
- Maximum Working Pressure: Up to 3.0 MPa (subject to wall thickness and geometry)
Ion Chromatography (IC) Cleanliness Specifications
Each production lot of Coil Tube is subjected to independent anion and cation determination via Ion Chromatography (IC) following ASTM E1422 / ASTM E2918 methodologies. The following detection limits and acceptance criteria are enforced:
| Ion Species | Classification | Detection Limit | Acceptance Criterion | Relevance |
|---|---|---|---|---|
| Na⁺ (Sodium) | Cation | 0.1 ppb | ≤ 1.0 ppb | Control of surface alkaline residues; prevents sodium silicate film formation on wafers |
| K⁺ (Potassium) | Cation | 0.1 ppb | ≤ 1.0 ppb | Indicator of cleaning agent carryover; critical for photolithography processes |
| Cl⁻ (Chloride) | Anion | 0.1 ppb | ≤ 0.5 ppb | Primary cause of stress corrosion cracking (SCC); must be minimized to protect passive film |
| SO₄²⁻ (Sulfate) | Anion | 0.1 ppb | ≤ 1.0 ppb | Originates from acid pickling residues; contributes to pitting initiation |
| Fe²⁺/Fe³⁺ (Iron) | Cation | 0.1 ppb | ≤ 2.0 ppb | Direct indicator of bulk metal leaching; contaminant for advanced node semiconductors |
| Ca²⁺ (Calcium) | Cation | 0.1 ppb | ≤ 1.0 ppb | Residual from water treatment; contributes to particulate formation |
| Mg²⁺ (Magnesium) | Cation | 0.1 ppb | ≤ 1.0 ppb | Water hardness indicator; potential nucleation site for scale deposition |
| NO₃⁻ (Nitrate) | Anion | 0.1 ppb | ≤ 1.0 ppb | Residual from nitric acid passivation; oxidizing agent in ultra-pure systems |
Manufacturing Process
- Raw Material Selection: Only certified ultra-low-carbon stainless steel strip from accredited mills is procured. Incoming material undergoes spectroscopic verification (OES) and chemical composition analysis to ensure trace element compliance.
- Forming & Coiling: Precision cold-rolled strip is formed into seamless tube geometry using roll-forming or drawing techniques. The tube is then coiled at controlled tension to maintain dimensional accuracy and surface integrity.
- Heat Treatment: Solution annealing is performed in a controlled atmosphere (argon or vacuum) to homogenize the microstructure, dissolve precipitates, and restore full corrosion resistance.
- Acid Pickling & Passivation: Multi-stage acid cleaning removes oxide scale and surface contaminants. Final passivation using dilute nitric acid or citric acid solutions establishes a stable chromium oxide passive layer.
- Electro-Polishing (Optional): For ultra-high purity applications, electro-polishing removes the top 5–20 μm of surface material, yielding a Ra ≤ 0.25 μm finish and significantly reducing surface contamination potential.
- Final Rinsing: Multi-stage rinsing with 18.2 MΩ·cm ultrapure water (UPW) ensures removal of all residual cleaning agents and dissolved ions.
- IC Testing & Release: Leachate samples are collected per ASTM E2918 protocols and analyzed via Ion Chromatography (IC) with suppressed conductivity detection. Only lots meeting all acceptance criteria are released for shipment.
Applications
- Semiconductor Manufacturing: Ultra-pure chemical delivery lines (UPL), wafer rinse systems, and process fluid transport in 7nm and below advanced fabrication nodes where ppb-level contamination is unacceptable.
- Photovoltaic (PV) Industry: High-purity hydrogen fluoride (HF) and sulfuric acid delivery systems for silicon wafer cleaning.
- Pharmaceutical & Biotech: Water-for-injection (WFI) loops, purified water (PW) distribution, and critical process fluid lines requiring biocompatible, low-leachate tubing.
- Electrochemical & Battery Manufacturing: Electrolyte delivery systems for lithium-ion battery production where trace metal contamination degrades cell performance.
- Laboratory & Analytical Instrumentation: Flow-through tubing for inductively coupled plasma mass spectrometry (ICP-MS) and ultra-trace analysis systems.
Quality Certifications & Compliance
- ISO 9001:2015 — Quality Management System certification covering all manufacturing and testing processes
- ISO 14001:2015 — Environmental Management System ensuring sustainable production practices
- ISO 45001:2018 — Occupational Health and Safety Management System
- ASTM A269 / ASME SA-269 — Standard specification for austenitic stainless steel seamless, welded, and heavily cold-worked tubing
- ASTM E1422 — Standard Practice for Chemical Analysis of Water for Determination of Anions by Ion Chromatography
- ASTM E2918 — Standard Practice for Chemical Analysis of Water for Determination of Cations by Ion Chromatography
- SEMI F57 — Semiconductor Equipment Materials Specifications for stainless steel tubing (where applicable)
- USP Class VI / FDA 21 CFR 177.1550 — Biocompatibility and food-contact compliance for pharmaceutical applications
- EN 10217-7 — European standard for austenitic stainless steel tubes for pressure purposes
Unique Selling Points
- Independent Anion/Cation Quantification: Unlike conventional total dissolved solids (TDS) or conductivity screening, this product undergoes species-specific IC analysis enabling precise identification and quantification of individual ionic contaminants at sub-ppb resolution.
- Wafer-Grade Contamination Control: Acceptance criteria are aligned with semiconductor industry requirements, ensuring that sodium, potassium, chloride, and sulfate leaching does not compromise wafer yield in advanced process nodes.
- Full Traceability: Each coil lot is accompanied by a comprehensive IC test report documenting individual ion concentrations, enabling downstream customers to integrate the data directly into their contamination budgets.
- Coil Form Advantage: Continuous coil delivery eliminates field joints and welds, reducing potential contamination points and enabling automated tubing processing systems for high-volume manufacturing.
Testing Methodology Notes
Ion Chromatography (IC) analysis is conducted using suppressed conductivity detection with high-purity carrier eluent (typically potassium hydroxide, KOH, for anion separation or methanesulfonic acid, CH₃SO₃H, for cation separation). Column efficiency is verified against NIST-traceable standard solutions prior to each analytical run. Detection limits are established at 3× the standard deviation of the blank signal. All test data is reported with associated measurement uncertainty in accordance with ISO/IEC 17025 requirements.
Ordering Information
Wenzhou Jixing Metal Materials Co., Ltd offers the Coil Tube in standard outer diameters ranging from 1/16 inch (1.6 mm) to 2 inch (50.8 mm) with wall thicknesses from 0.035 inch (0.89 mm) to 0.250 inch (6.35 mm). Custom geometries, special alloy grades, and tailored IC testing protocols are available upon request. All products ship with full lot traceability documentation and certified IC cleanliness reports.