Tag Archives: ISO 14644-1 Class 5 wipes

High-density wipes for precision cleaning in Class 100 cleanrooms.

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Class 100 cleanrooms (equivalent to ISO 14644-1 Class 5) demand uncompromising cleaning precision—allowing no more than 100 particles (≥0.5μm) per cubic foot of air. In environments like semiconductor wafer fabrication, medical implant manufacturing, or microelectronics assembly, even a single sub-micron particle or fiber can ruin high-value products or compromise sterile conditions. High-density cleanroom wipes, engineered with tightly woven microfiber or non-woven structures (250–400 gsm), outperform low-density alternatives by delivering unmatched control over particles, residues, and contamination—elevating cleaning precision to meet Class 100 standards. Below is a detailed breakdown of how these wipes enhance precision and support critical cleanroom operations.

1. Ultra-Low Particle Trapping: Targeting Sub-Micron Contaminants

Class 100 cleanrooms require removal of particles as small as 0.1μm—something low-density wipes often miss. High-density wipes achieve this through:
  • Tight Weave Construction: Their dense fiber matrix creates millions of tiny capillary channels that trap particles as small as 0.05μm—far below the Class 100 particle limit. For example, when cleaning wafer chucks (a critical component in semiconductor manufacturing), high-density wipes capture residual silicon fragments and dust that would otherwise cause “stain defects” on 5nm/3nm wafers.
  • Continuous-Filament Fibers: Made from 100% polyester or polypropylene continuous filaments (not staple fibers), these wipes shed ≤1 fiber per use. This eliminates fiber contamination—a top cause of product rejects in Class 100 environments. Low-density wipes, by contrast, can shed 5–10 fibers per wipe, risking cross-contamination of sterile medical devices or microchips.
  • Uniform Surface Contact: The smooth, consistent texture of high-density wipes ensures even contact with surfaces (e.g., optical lenses, sterile packaging). This prevents “missed spots” where particles accumulate, a common flaw with low-density wipes that have uneven fiber distribution.

2. Residue-Free Cleaning: Eliminating Chemical and Ionic Contaminants

Class 100 cleanrooms also prohibit trace residues (e.g., solvent films, ionic deposits) that can degrade product performance. High-density wipes address this by:
  • Controlled Absorption of Cleaning Solutions: When used with high-purity solvents (e.g., 99.9% IPA, deionized water), their dense structure absorbs and retains liquids evenly—preventing over-saturation (which leaves solvent residues) or under-wetting (which fails to dissolve contaminants). For medical device molds, this means no residual cleaning agents that could leach into implants.
  • Minimal Extractables: High-density wipes undergo rigorous testing to ensure they release fewer than 10ppb of ions (e.g., sodium, chloride) and organic compounds. This is critical for semiconductor cleanrooms, where ionic contaminants can corrode copper PCB traces or disrupt wafer etching processes. Low-density wipes often have higher extractable levels, making them unsuitable for Class 100 applications.
  • Fast, Even Evaporation: When used as pre-wet wipes, their dense fibers distribute solvent uniformly across surfaces, ensuring rapid, streak-free evaporation. This eliminates water spots or solvent rings that plague low-density wipes, which often leave uneven moisture patterns.

3. Durability for Precision Handling: Avoiding In-Use Contamination

Cleaning precision is lost if wipes tear or fray during use—releasing particles into the cleanroom air. High-density wipes maintain integrity through:
  • Reinforced Edges: Heat-sealed or laser-cut edges prevent fraying, even when wiping textured surfaces (e.g., equipment seams, grooved tooling). This means one wipe can clean multiple surfaces without disintegrating, reducing the need for frequent wipe changes (a source of cross-contamination).
  • Abrasion Resistance: Their thick, dense structure withstands gentle wiping (required for delicate Class 100 surfaces like optical masks) without breaking down. Low-density wipes, by contrast, may tear after 1–2 passes, forcing technicians to use more wipes and increasing particle release.
  • Consistent Performance: Each high-density wipe delivers the same particle-trapping and residue-removal efficacy, eliminating variability from wipe to wipe. This consistency is critical for meeting Class 100’s strict quality control requirements, where even minor performance fluctuations can lead to batch rejects.

4. Application-Specific Precision: Tailored to Class 100 Tasks

High-density cleanrooms wipes are optimized for the unique demands of Class 100 operations:
  • Wafer and Optic Cleaning: Small, 4”x4” high-density wipes reach tight spaces (e.g., between wafer handler grippers) without touching adjacent components, ensuring precision cleaning without damaging sensitive parts.
  • Sterile Surface Maintenance: For medical device cleanrooms, gamma-irradiated high-density wipes maintain sterility while removing particulate contamination—critical for implantable devices like pacemakers or stents.
  • Equipment Calibration Support: When cleaning metrology tools (used to measure wafer dimensions), high-density wipes remove dust without altering tool calibration—ensuring accurate measurements that keep production within Class 100 tolerances.
In Class 100 cleanrooms, where precision is non-negotiable, high-density cleanroom wipes are more than a cleaning tool—they are a critical component of quality assurance. By trapping sub-micron particles, eliminating residues, and maintaining durability, they ensure cleaning meets the strictest standards, protecting products, reducing rejects, and supporting reliable manufacturing.

Standard Use of Cleaning Wipes in Class 100 Cleanrooms

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Class 100 cleanrooms (equivalent to ISO 14644-1 Class 5) enforce ultra-stringent contamination control—allowing no more than 100 particles (≥0.5μm) per cubic foot of air. In environments like semiconductor wafer fabrication, medical device manufacturing, or microelectronics assembly, even a single fiber or trace residue can ruin high-value products. Cleanroom wipes (dry, lint-free variants) and cleaning wipes (pre-moistened with high-purity solutions) are critical tools here, but their effectiveness depends on strict adherence to standard operations (SOPs) that minimize particle generation, prevent cross-contamination, and ensure compliance. Below is a comprehensive breakdown of these SOPs, tailored to Class 100 cleanroom requirements.

1. Pre-Operation Preparation: Ensure Wipe and Operator Readiness

Before entering the Class 100 cleanroom, thorough preparation eliminates external contamination risks:
  • Wipe Selection & Inspection:
    • Choose wipes certified to ISO 14644-1 Class 5 (or better) with ultra-low linting (≤1 particle ≥0.1μm per wipe) and, if using pre-moistened cleaning wipes, a residue-free solution (e.g., 99.9% IPA, deionized water).
    • Inspect wipes under a Class 100-compatible light (e.g., LED task light) for tears, loose fibers, or visible contaminants. Discard any defective wipes—even minor flaws can shed particles.
  • Operator Gowning & Grounding:
    • Don cleanroom-appropriate attire (e.g., full-body bunny suit, gloves, face mask, shoe covers) following ISO 14644-3 gowning protocols to prevent operator-borne particles.
    • For anti-static needs (e.g., semiconductor cleanrooms), wear an ESD wrist strap connected to a grounded surface and anti-static gloves—this prevents static from attracting particles to wipes or surfaces.
  • Wipe Storage & Handling:
    • Store unopened wipes in sealed, cleanroom-grade packaging (e.g., foil-lined bags with zip closures) in a Class 100 storage cabinet. Never bring non-Class 100 wipe packaging into the cleanroom.
    • Open wipe dispensers only inside the cleanroom, and reseal them immediately after each use to avoid exposure to ambient air (which carries particles).

2. Standard Wiping Procedures for Class 100 Cleanrooms

The wiping technique directly impacts particle control—follow these steps for both dry cleanroom wipes and pre-moistened cleaning wipes:

A. Dry Cleanroom Wipes (for Particle Removal)

Use dry wipes first to eliminate loose dust before wet cleaning—this prevents particles from being pushed into surfaces or dissolved in cleaning solutions:
  1. Wipe Folding: Fold the dry wipe into a 4-layer pad (e.g., 4”x4” from a 8”x8” wipe). This creates a dense, low-linting surface and reduces the risk of the wipe edge fraying (a common particle source).
  2. Wiping Pattern: Wipe in a single, continuous direction (e.g., horizontal for flat surfaces like workbenches, vertical for walls) with overlapping strokes (50% overlap). Never use circular motions—these redistribute particles instead of trapping them.
  3. Pressure Control: Apply light, even pressure (≤1 psi). Excessive force compresses the wipe’s fibers, reducing particle-trapping capacity and increasing friction (which can generate static).
  4. Wipe Rotation: Rotate the wipe to a clean layer after every 2–3 strokes. Once all layers are used, discard the wipe immediately in a Class 100-compatible waste bin (sealed, anti-static, if needed).

B. Pre-Moistened Cleaning Wipes (for Residue/Oil Removal)

Use cleaning wipes only after dry particle removal, and prioritize residue-free solutions to avoid leaving contaminants:
  1. Moisture Check: Ensure the wipe is damp (not dripping). Excess liquid can pool in crevices (e.g., equipment seams) and evaporate, leaving mineral deposits or solvent residues. Blot excess moisture on a clean dry wipe if needed.
  2. Targeted Cleaning: For small surfaces (e.g., wafer chucks, optical lenses), use the edge of the folded wipe to reach tight spaces. For large areas, divide the surface into 1ft x 1ft sections and clean one section at a time to avoid missing spots.
  3. Evaporation Wait: After wiping, allow the surface to air-dry completely (10–30 seconds, depending on the solution) in the cleanroom’s filtered air. Do not use compressed air to speed drying—this can stir up particles.
  4. Post-Clean Dry Wipe: For critical surfaces (e.g., semiconductor wafers), follow the cleaning wipe with a fresh dry wipe to ensure no residue remains.

3. Post-Operation Protocols

  • Waste Disposal: Place used wipes in a sealed, labeled waste container (marked “Class 100 Cleanroom Waste”) and remove it from the cleanroom at the end of each shift. Do not leave used wipes inside—they can release trapped particles.
  • Dispenser Maintenance: Clean wipe dispensers weekly with a dry Class 100 wipe to remove dust from the opening. Replace dispensers if they show signs of wear (e.g., cracked lids) that could allow contamination.
  • Documentation: Log wipe usage (lot number, quantity, cleaning area) and any anomalies (e.g., defective wipes, particle spikes) in the cleanroom’s SOP log. This supports traceability for compliance audits (e.g., FDA, SEMI).

4. Critical Compliance Checks

  • Particle Monitoring: After cleaning, use a particle counter to verify surface particle levels (≤1 particle ≥0.5μm per cm²) and air particle counts (≤100 particles ≥0.5μm per cubic foot).
  • Residue Testing: For pre-moistened wipes, conduct monthly residue tests (e.g., ion chromatography, FTIR spectroscopy) to confirm no solvent or additive residues remain on cleaned surfaces.
By following these standard operations, cleanroom wipes and cleaning wipes consistently meet Class 100 requirements—protecting products from contamination, ensuring regulatory compliance, and maintaining the cleanroom’s integrity for high-precision manufacturing.

Buyer’s Guide: Anti-Static Wipes for Class 100 Cleanrooms

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Class 100 cleanrooms (per ISO 14644-1, equivalent to ISO Class 5) represent the gold standard for ultra-low-contamination environments—used in semiconductor wafer fabrication (≤5nm processes), medical device manufacturing (e.g., implantable sensors), and aerospace component assembly. In these spaces, even 1 particle (≥0.5μm) per cubic foot of air or a tiny electrostatic discharge (ESD) can ruin high-value products or compromise sterile conditions. Anti-static cleanroom wipes for Class 100 environments are not just “clean”—they must meet rigorous standards for particle control, static dissipation, and material purity. This guide outlines critical criteria to ensure you select wipes that protect your processes, equipment, and products.

1. Prioritize Cleanroom Classification Compliance

Class 100 cleanrooms demand wipes certified to match their strict particle limits—never compromise on this foundational requirement:
  • ISO 14644-1 Class 5 Certification: Verify the wipe manufacturer provides third-party testing reports confirming compliance with ISO Class 5 (the international equivalent of Class 100). This ensures the wipe releases ≤10 particles (≥0.1μm) and ≤1 particle (≥0.5μm) per wipe during use—critical for avoiding particle-induced defects in semiconductors or medical devices.
  • Non-Shedding Material: Choose wipes made from ultra-low-linting substrates like 100% continuous-filament polyester or polypropylene. Avoid blended fibers (e.g., polyester-cotton) or staple-filament materials—these shed microfibers that can float in Class 100 air and contaminate surfaces. Test for linting by wiping a black, non-abrasive surface and inspecting for visible fibers under 10x magnification.

2. Validate Anti-Static Performance (Non-Negotiable for ESD-Sensitive Environments)

ESD is a silent risk in Class 100 cleanrooms—static charges can attract particles or damage ESD-sensitive components (e.g., wafer sensors, microchips). Evaluate wipes on these metrics:
  • Surface Resistance Range: Select wipes with surface resistance between 10⁶–10¹¹ Ω (per ANSI/ESD S20.20 standards). This “static-dissipative” range ensures charges are safely grounded without creating electrical arcs. Avoid “conductive” wipes (resistance <10⁶ Ω) for general use—they may cause unintended electrical pathways in delicate equipment.
  • Static Decay Time: Confirm the wipe’s static decay time (time to reduce a 5000V charge to <50V) is ≤2 seconds. Slow decay allows static to linger, increasing particle attraction. Ask manufacturers for IEC 61340-5-1 test data to validate this performance.
  • Anti-Static Treatment Durability: Ensure the anti-static coating is “permanent” (not just a surface spray). Wipes for Class 100 cleanrooms should retain their static-dissipative properties through multiple uses (if reusable) or during storage (for single-use options). Avoid wipes where anti-static efficacy degrades with humidity or time.

3. Match Wipe Type to Class 100 Cleaning Tasks

Class 100 cleanrooms require targeted cleaning—choose wipe formats and formulations based on your specific needs:
  • Dry Wipes: Ideal for removing loose, dry particles (e.g., dust on wafer chucks, lithography tool exteriors). Opt for dry wipes with a dense, smooth texture—this traps particles instead of pushing them around. Use dry wipes first before wet cleaning to avoid embedding particles into surfaces.
  • Pre-Wet Wipes: For removing oils, flux residues, or fingerprints (common in electronics manufacturing), select pre-wet wipes with high-purity solvents:
    • IPA (Isopropyl Alcohol) Wipes: Use 99.9% pure IPA (for oil-free surfaces) or 70% IPA + 30% deionized (DI) water (for better residue dissolution). Ensure the IPA is “semiconductor-grade” (≤10ppb impurities) to avoid trace chemical contamination.
    • Residue-Free Disinfectant Wipes: For sterile Class 100 environments (e.g., medical device labs), choose wipes with hydrogen peroxide (3%) or peracetic acid formulations—these disinfect without leaving toxic or particulate residues.
  • Size and Thickness: Select smaller wipes (e.g., 4”x4”) for precision tasks (e.g., cleaning around microchips) to reduce waste and avoid over-wiping. Thicker wipes (≥80gsm) offer better durability—critical for avoiding tearing (which releases particles) during use.

4. Evaluate Manufacturing and Packaging Quality

Even the best wipe material can be compromised by poor manufacturing or packaging:
  • Cleanroom-Grade Production: Ensure wipes are manufactured in an ISO Class 5 (or better) facility. This prevents pre-use contamination from the factory floor. Ask for a “Certificate of Analysis (CoA)” with each batch, detailing particle counts and static performance.
  • Sealed, Anti-Static Packaging: Wipes should arrive in airtight, static-shielding packaging (e.g., foil-lined bags with resealable zippers). Once opened, store wipes in a Class 100-compatible dispenser with a dust-tight lid—exposure to non-Class 100 air will contaminate the wipes.
  • Shelf-Life and Storage Conditions: Check the manufacturer’s shelf-life (typically 12–24 months for pre-wet wipes). Store wipes in a cool (15–25°C), dry (30–50% RH) area—extreme temperatures or humidity degrade anti-static treatments and solvent purity.

5. Avoid Common Pitfalls

  • Don’t Sacrifice Quality for Cost: Cheaper wipes may skip Class 100 certification or use low-grade materials—costly defects from contamination will far outweigh initial savings.
  • Don’t Reuse Single-Use Wipes: Single-use Class 100 wipes are designed for one pass—reusing them traps particles and degrades anti-static performance.
  • Don’t Overlook Compatibility: Test wipes on a small, non-critical surface (e.g., a spare wafer or equipment part) to ensure they don’t damage coatings (e.g., anti-reflective lens coatings) or plastics.
By following these criteria, you’ll select anti-static cleanroom wipes that not only meet Class 100 standards but also protect your high-value processes from contamination and ESD—ultimately reducing defects, minimizing downtime, and ensuring regulatory compliance.