Tag Archives: Cleanroom wipes

  • Low-lint and non-shedding materials

  • High absorbency and chemical resistance

  • Soft texture to prevent surface damage

  • Available in various sizes and materials (polyester, microfiber, cellulose blends)

  • Suitable for use in ISO Class 5 and above cleanrooms

Applications:
Cleanroom wipes are ideal for cleaning delicate surfaces in semiconductor manufacturing, pharmaceuticals, biotechnology, electronics assembly, medical devices, and optical industries, ensuring contamination control and product quality.

Cleanroom Wipe Tests: 7 Key Standards & Insights

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Cleanroom wipes are essential consumables in cleanrooms and high-purity industries such as electronics and pharmaceuticals. Their performance directly affects the cleanliness of production environments and product yield. Currently, multiple testing standards cover aspects such as anti-static properties, particle release, material durability, and sterilization validation. This article systematically summarizes seven mainstream testing standards, explaining their applicable scopes and core requirements, while providing practical interpretation to help enterprises improve product quality and competitiveness.

1. IEST-RP-CC003.4:2011 — Cleanroom Garment System Requirements

Developed by the Institute of Environmental Sciences and Technology (IEST), this standard primarily regulates the production and testing of cleanroom garments and associated fabrics.

  • Material Selection: Woven fabrics preferably use polyester or polyester-carbon composite fibers to reduce particle shedding. Disposable cleanroom garments utilize nonwoven fabrics such as spunbond or meltblown layers.

  • Key Tests:

    • Particle retention rate is evaluated using the Helmke Drum test, focusing on 0.3–0.5 μm particles for cleanliness classification.

    • Sterilization validation must comply with ISO 11137, achieving a sterility assurance level (SAL) of 10⁻⁶.

  • Applications: Suitable for high-cleanliness industries like pharmaceuticals and microelectronics.

2. IEST-RP-CC004.4:2019 — Cleanroom Wiping Materials Evaluation

Focuses on functional testing of wipes, including particle residue and anti-static performance.

  • Particle Residue: Evaluates non-volatile residue (NVR) content via microparticle detection methods such as ASTM E1560 gravimetric analysis.

  • Anti-Static Performance: Requires surface resistivity ≤1×10¹¹ Ω and static decay time ≤2 seconds (per IEC 61340-5-1).

  • Suitability Classification: Recommends wipe types according to cleanroom class (ISO 14644-1), e.g., microfiber wipes for higher-class areas.

3. GB/T 24249-2009 — Anti-Static Cleanroom Fabrics (Chinese National Standard)

Specifies performance requirements for anti-static cleanroom apparel and gloves.

  • Technical Requirements:

    • Surface resistivity range of 1×10⁵ to 1×10⁹ Ω to ensure effective static dissipation.

    • Abrasion resistance tested by Martindale method with mass loss ≤5%.

  • Applications: Electronics, semiconductor, and pharmaceutical cleanroom garments.

4. SJ/T 11480-2014 — Anti-Static Cleanroom Wipes (Electronics Industry Standard)

Targets particle and chemical compatibility requirements for electronics wipes.

  • Tests:

    • Non-volatile residue (NVR) ≤0.1 mg/cm² (ASTM E1560).

    • Extractables must comply with electronics cleaning demands.

  • Edge Sealing: Laser or ultrasonic sealing recommended to minimize fiber shedding.

5. FZ/T 64056-2015 — Cleanroom Wipes (Textile Industry Standard)

Covers woven, knitted, and nonwoven wipes, emphasizing particle release and absorbency.

  • Cleanliness: Suitable for ISO Class 5 (Class 100) cleanrooms with particle release ≤300 particles/m³ (≥0.5 μm).

  • Absorbency: Minimum water absorption of 400 g/m² to ensure cleaning efficiency.

6. Seagate Testing Standard

Seagate’s proprietary testing standards can be referenced by industry participants to meet specific customer requirements.

7. Customer Standards

Customer-specific standards are the most critical quality benchmarks.

  • Regardless of industry norms, meeting customers’ cleanliness class and basis weight requirements is essential for product acceptance.

  • Example: One client shifted from low-cost wipes bought on e-commerce platforms (lacking cleanroom classification) to USTER products with guaranteed cleanroom grades (minimum Class 10,000 for wipes and Class 1,000 for microfiber wipes), resulting in a significant quality improvement.

Summary and Recommendations

  1. Selection Basis: Choose products compliant with relevant cleanroom classes (ISO 14644) and industry needs (electronics, pharmaceuticals).

  2. Quality Control Focus: Monitor particle residue, anti-static properties, durability, and sterilization efficacy regularly.

  3. Future Trends: Standards are evolving towards environmental sustainability (e.g., biodegradable nonwovens) and smart testing (real-time particle monitoring).

USTER is committed to continuously raising cleanroom wipe quality standards to support industries in achieving higher cleanliness levels and improved product yields.

Cleanroom Wipes: APC Testing & Particle Control

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In industries with extremely high cleanliness requirements such as semiconductor manufacturing, precision electronics, and medical equipment, the Air Particle Count (APC) of cleanroom wipes is a key indicator to evaluate their cleanliness and suitability. Even microscopic particles at very low concentrations can cause circuit shorts, device failures, or contamination of medical instruments, affecting product yield and safety. This article provides a detailed overview of the purpose, principles, procedures, and quality control aspects of APC testing for cleanroom wipes, helping enterprises scientifically select high-quality wipes.

1. Purpose and Significance of APC Testing

APC testing aims to simulate particle release during the dry, dynamic use of cleanroom wipes and quantitatively assess their potential contamination risk to the cleanroom environment. In ultra-clean processes like semiconductor wafer fabrication, particle presence can directly cause manufacturing defects. APC testing helps screen low-particle-release wipes to ensure they meet strict cleanroom requirements.

2. Principles and Key Parameters of APC Testing

  1. Testing Principle
    APC testing is based on light scattering technology. Particles suspended in air scatter a laser beam; the intensity of scattered light correlates with particle size and number. Particle counters capture the scattered signals, enabling precise counting of particles in the 0.3–2.0 μm size range, focusing especially on critical particles ≥0.5 μm.

  2. Key Parameters

  • Testing Equipment: Helmke Drum simulates real wiping action by rotating at 10 rpm, generating mechanical friction similar to actual use.

  • Units: Results are reported as counts/ft³/min/pc (particles per cubic foot per minute per piece) or counts/m² (particles per square meter), indicating particle release intensity per unit area or per wipe piece.

  • Sample Requirements: Five sealed samples with neat-cut edges to avoid fiber shedding from edges that might interfere with results.

3. Standardized Testing Procedure

  1. Sample Preparation

  • Samples are unpacked in an ISO Class 5 or better clean environment to avoid external contamination.

  • Cleanroom tweezers are used to fix wipes flat onto the Helmke Drum’s inner wall, avoiding folds or pressure.

  1. Equipment Operation

  • The drum rotates steadily at 10 rpm, simulating wiping-induced mechanical stress.

  • The air sampling tube is positioned 5 ± 2 cm from the drum’s edge, connected via flexible conductive tubing to the particle counter, sampling at 28.3 L/min.

  1. Data Collection

  • The particle counter measures particle counts mainly ≥0.5 μm over about 40 minutes per sample, recording the dynamic release curve and calculating average particle release.

4. Quality Control and Considerations

  1. Environmental Control

  • Laboratory conditions are maintained at 20–25°C, 40–60% humidity, and ISO Class 5 cleanliness.

  • The same operator performs all tests to minimize human error.

  1. Equipment Calibration

  • Regular calibration of particle counter sensitivity and Helmke Drum speed is mandatory.

  • Blank control tests (empty drum runs) are conducted to exclude background particle interference.

  1. Sample Uniformity

  • Wipes from different batches and edge finishing methods (laser cutting, ultrasonic sealing) are tested separately since edge quality directly impacts fiber shedding.

5. Application Scenarios and Standards Reference

  • Semiconductor Manufacturing: Compliance with Class 1 cleanroom standards (≤10 particles ≥0.1 μm per cubic meter) to prevent manufacturing defects.

  • Medical Sterile Packaging: Minimizing microparticle contamination to ensure surgical instrument and pharmaceutical safety.

  • Optical Device Cleaning: Avoiding scratches or fogging on lenses and sensors caused by particulate matter.

Relevant Standards:

  • SJ/T 11480-2014: Specifies instrument parameters and operational procedures for APC testing.

  • ASTM E1560: Relates non-volatile residue (NVR) analysis to particle release characteristics.

6. Conclusion

APC testing of cleanroom wipes scientifically simulates actual usage environments to quantify particle release risk, providing essential guidance for selecting materials suitable for high-cleanliness industries. As cleanroom technologies advance, future APC testing will integrate micro/nano particle characterization and AI data analytics to drive upgrades in wipe performance standards.

Cleanroom Wipes/Swabs: Absorption Test Methods

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1. Testing Principle and Importance

Cleanroom wipes and swabs are essential consumables in precision manufacturing industries. Their liquid absorption performance directly affects cleaning efficiency in sectors such as semiconductors, optical panels, and medical devices. This test quantifies liquid absorption per unit area or weight of material, providing critical data for material selection and process validation. The testing follows standards like IEST-RP-CC004.3, focusing on absorption characteristics of typical industrial solvents such as ultrapure water and isopropyl alcohol (IPA).

Lab technicians at Youstech are shown testing the water absorbency of cleanroom wipes.

2. Key Influencing Factors

2.1 Material Structural Properties

  • Fiber Type: Polyester/nylon blends absorb 15–20% more IPA than pure cotton materials.

  • Fabric Weight: 80g/m² wipes absorb 30–40% more liquid compared to 50g/m² fabric.

  • Weaving Technique: Knitted fabrics retain over 25% more liquid than plain-woven fabrics.

  • Surface Treatment: Hydrophilic treatments can increase ethanol absorption by 50–70%.

2.2 Unique Swab Structure

  • Winding Density: Tips with 8–10 wraps per millimeter retain 15% more liquid than loosely wrapped ones.

  • Rod Material: PP handles offer better ESD performance than wooden rods (surface resistance <10⁹Ω).

3. Standardized Testing Procedure

3.1 Sample Preparation

  • Wipes: Cut 5 specimens of 10×10 cm each (as per ASTM D5729).

  • Swabs: Select 5 swabs from the same batch with intact cotton tips.

  • Pre-treatment: Dry at 40°C for 2 hours, then equilibrate at 23±1°C and 50±5% RH for 24 hours.

3.2 Test Settings

  • Soaking Solutions: Ultrapure water (18.2 MΩ·cm) and ≥99.7% pure isopropyl alcohol.

  • Immersion Time: 60±5 seconds (based on SEMI E129 standard).

  • Drip-off Angle & Time: 45° hanging angle, 120 seconds drainage.

3.3 Precision Weighing Process

Using a 0.0001g accuracy balance:

  • Wipe Absorption (mL/m²) = (Wet weight − Dry weight) / (Solution density × Area)

  • Swab Absorption (μL/tip) = (Wet weight − Dry weight) × 1000 / Solution density

4. Key Quality Control Points

  • Environment: Class 100 cleanroom with temperature fluctuation ≤±0.5°C/h

  • Handling: Use ESD-safe tweezers to avoid contamination.

  • Data Validation: Conduct 3 parallel tests per sample; RSD ≤ 5%

  • Calibration: Perform 3-point weight calibration weekly (0.1g, 1g, 10g)

This testing system not only supports quality control of cleanroom consumables but also contributes valuable data for R&D of new materials. As 5G chip manufacturing pushes cleanliness standards toward the 0.1μm level, liquid absorption testing is evolving toward nanoscale observation and in-situ dynamic analysis, ushering cleanroom materials into a new era of precision diagnostics.

Cleanroom Wipes: Electrostatic Test Methods

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In electrostatic-sensitive environments such as electronics manufacturing and precision instrument maintenance, cleanroom wiping consumables (e.g., cleanroom wipes, cleanroom paper, and swabs) must offer reliable electrostatic discharge (ESD) protection. Effective dissipation of static electricity is essential to prevent damage to sensitive components. This article systematically outlines the commonly used test methods for evaluating anti-static properties of these materials, based on industry standards and real-world requirements.

1. Surface Resistance Method – Basic Conductivity Assessment

Principle:
Surface resistance is the ratio of direct current voltage to current between two points on the surface of a material (unit: ohms, Ω). Lower resistance indicates better conductivity and stronger ESD dissipation capability.

Testing Procedure:

  • Sample Preparation: Select 5 samples and pre-condition them in a controlled environment (23±2°C, 50±5% RH) for at least 4 hours.

  • Measurement: Place the electrodes (or weighted probes) of the surface resistance tester on the sample, press the test button, and record the reading.

Evaluation Criteria:

  • Anti-static material: Resistance < 10¹¹ Ω

  • High-quality anti-static material: 10⁵ Ω – 10⁹ Ω (balanced ESD dissipation and insulation)

  • Insulating material: Resistance > 10¹² Ω (prone to static buildup)

Advantages:
Quick and simple; suitable for on-site screening in production environments.

2. Decay Time & Half-Life Method – Charge Dissipation Efficiency

Principle:
After charging the sample using a high-voltage source, its voltage decay to 50% of the initial level (half-life) or complete decay is measured using a non-contact electrostatic voltmeter. This evaluates how quickly the material dissipates static charges.

Testing Procedure:

  • Sample Preparation: Pre-treat 10 samples for at least 4 hours in a controlled environment.

  • Charge & Measure: Charge using corona discharge or friction method and monitor the decay curve of voltage over time.

Key Indicator:
Shorter decay time = better ESD performance. Semiconductor industries typically require decay time < 0.1 seconds.

Application:
Ideal for high-ESD-sensitive applications like chip fabrication.

3. Triboelectric Voltage Method – Real-World Friction Simulation

Principle:
The sample is rubbed against a standard fabric (e.g., nylon cloth) under a specified tension until it reaches electrostatic stability. The peak and average voltages generated simulate ESD risk from actual wiping motions.

Testing Procedure:

  • Equipment: A friction apparatus and electrostatic voltmeter compliant with GB/T 24249-2009 standard.

  • Sample Details: Pre-treat 10 samples for ≥4 hours; each test lasts 30 minutes.

Evaluation Criteria:

  • Grade 1 anti-static material: Friction voltage ≤ 200V

  • Grade 2 material: 200V–500V

Advantages:
Highly practical; mimics real-use conditions and supports cleanroom material classification.

4. Testing Conditions & Key Guidelines

  • Environmental Control: All tests must be conducted at 20–25°C and 40%–60% RH.

  • Pre-treatment Importance: Eliminates moisture-related influence on resistance values to ensure data reliability.

  • Sample Quantity: Surface resistance test requires 5 samples; other methods require 10 to account for material variability.

  • Data Recording: Must document max, min, and average values for comprehensive performance evaluation.

5. Conclusion & Selection Recommendations

Multiple tests are essential to comprehensively evaluate the anti-static performance of cleanroom wiping materials:

  • Surface Resistance Method assesses base-level conductivity.

  • Decay Time Method evaluates charge dissipation speed.

  • Triboelectric Method simulates practical static generation risks.

For real-world application, users should align with industry standards (e.g., GB/T 24249-2009) and operational scenarios (e.g., Class 100 cleanrooms, high-precision electronics assembly). It is recommended to select products with resistance between 10⁵–10⁹ Ω and triboelectric voltage ≤200V to ensure effective ESD control while maintaining operational efficiency.

Premium Cleanroom Wipes: Key Requirements Guide

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In industries with extremely high cleanliness requirements such as electronics optics, semiconductor manufacturing, and biopharmaceuticals, cleanroom wipes are essential consumables that ensure process stability and product quality. A high-quality cleanroom wipe must not only have excellent cleaning efficiency but also meet strict physical, chemical, and biological standards. This article analyzes the seven core performance parameters that high-quality cleanroom wipes should satisfy, helping enterprises make precise selections to improve cleanroom process stability and product yield.

1. Strict Control of Particle Shedding
Particle shedding during use directly affects the cleanliness level.

  • Visible Particles: The wipe should not shed visible fibers or particles to avoid scratching or secondary contamination. High-density weaving and laser or ultrasonic sealing reduce fiber breakage risk.

  • Submicron Particles: The release of submicron particles must be measured by laser particle counters and comply with ISO 14644-1 standards. Using ultrafine fibers combined with multiple rounds of ultrapure water cleaning improves cleanliness.

2. Fiber Shedding Suppression
Fiber residue is a major concern affecting wiping effectiveness and equipment safety.

  • Use nonwoven fabrics or woven fabrics sealed by laser cutting or ultrasonic welding.

  • Comply with IEST-RP-CC004.3 fiber release testing to ensure particle emissions meet strict criteria.

3. Extremely Low Chemical Residue
High cleanliness applications are sensitive to chemical contamination and require strict control of ions and non-volatile residues (NVR).

  • Ion Contamination: Tested per IPC TM-650 2.3.28 to ensure no soluble ionic contamination.

  • Non-Volatile Residues: Use ultrapure water cleaning and solvent-free manufacturing to prevent organic or inorganic deposits that may corrode equipment or affect chemical reactions.

4. Biological Load Control
Especially in pharmaceutical and biological labs, wipes must meet sterile or low microbial load standards.

  • Sterilization treatments reduce microbial counts.

  • Packaging with double clean bags or vacuum sealing prevents contamination during transport and storage.

5. Anti-Static Performance
Electrostatic discharge (ESD) can damage sensitive electronic components; high-quality wipes need stable anti-static properties.

  • Surface resistivity should range between 10⁵ to 10⁹ ohms, complying with ANSI/ESD S20.20 standards.

  • Permanent anti-static additives such as carbon fibers or conductive threads are preferred over temporary coatings.

6. Clean Packaging and Traceability

  • Class 100 wipes must be packaged in Class 100 cleanrooms to avoid external contamination.

  • Provide detailed batch test reports including particle counts, ion content, and microbial data, meeting ISO 9001 quality management requirements.

Summary
High-quality cleanroom wipes are vital guardians of precision manufacturing and R&D, with performance spanning material selection, manufacturing processes, stringent testing, and clean packaging. When selecting wipes, users should consider specific application requirements, reference industry standards, and verify through third-party testing to ensure optimal particle shedding, chemical contamination, biological safety, electrostatic control, and traceability. Only wipes that balance these multidimensional performance factors can truly act as the “invisible protectors” of clean environments, helping enterprises continuously enhance product quality and process stability.

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In high-cleanliness environments such as semiconductor manufacturing, biopharmaceuticals, and aerospace, cleanroom wipes are critical consumables for maintaining cleanroom classification and process stability. The IEST (Institute of Environmental Sciences and Technology) released the IEST-RP-CC004.4 standard, providing a scientific and systematic testing framework for quality control of cleanroom wipes. This article analyzes the key test items and their purposes based on the standard, revealing its technical value in cleanroom applications.

1. Particle Release Characterization

  • Liquid Particle Counting (LPC, 0.5–20 μm):
    Using a liquid particle counter combined with orbital shaking to simulate mechanical friction on wet wipes, quantifying released particles between 0.5 and 20 microns to prevent contamination of precision instruments and interference with optical surfaces.

  • Fiber Analysis (>100 μm):
    Optical microscopy is used to detect large residual fibers or particles after orbital shaking, preventing clogging of microporous structures or mechanical failures caused by macroscopic particles.

  • Airborne Particle Counting (APC, 0.3–10 μm):
    Helmke drum simulates dry state wipe motion, and airborne particle counters monitor particle release between 0.3 and 10 microns to assess particulate risk during dynamic cleanroom operations.

2. Chemical Contaminant Analysis

  • Ion Content Test (IC):
    After extraction with deionized water, ion chromatography detects anions (F⁻, Cl⁻, NO₃⁻, etc.) and cations (Na⁺, K⁺, Ca²⁺, etc.) to prevent ion residues from corroding electronic components or interfering with chemical processes, especially crucial in semiconductor wafer manufacturing.

  • Non-Volatile Residue (NVR) Test:
    Short-term extraction with deionized water and isopropanol followed by evaporation and weighing quantifies transferable oils and polymers, preventing deposition on sensitive surfaces.

  • Fourier Transform Infrared Spectroscopy (FTIR):
    After hexane extraction, FTIR detects organic compounds such as silicone oils, amides, and phthalates (DOP), identifying potential contamination sources to protect optical components and ensure biocompatibility.

3. Physical Performance and Functional Evaluation

  • Liquid Absorption Capacity and Rate:
    Measures maximum liquid uptake per unit area and absorption speed, ensuring wiping efficiency and avoiding contamination from insufficient liquid absorption leading to repeated wiping.

  • Surface Static Charge Test:
    Measures surface resistivity to control static accumulation risk and prevent electrostatic discharge (ESD) damage to electronic components.

4. Biological Contamination Control

  • Bioburden Test:
    Microbial culture methods quantify aerobic bacteria and fungi counts on wipe surfaces, ensuring wipes do not introduce microbial contamination in pharmaceutical or biological lab environments.

5. Technical Significance of the Standard
IEST-RP-CC004.4 comprehensively covers physical, chemical, and biological performance indicators of cleanroom wipes through multi-dimensional testing. It offers graded particle control from submicron to macroscopic fibers, compatible with ISO Class 1 to 5 cleanrooms, tightly controls ions and organic contaminants for semiconductor and optical industries, and verifies absorption efficiency and antistatic performance to guarantee operational reliability. This standard provides a scientific basis for wipe selection, acceptance, and quality management and is a core technical specification to maintain clean environments in high-value industries.

Conclusion:
By rigorously following the IEST-RP-CC004.4 standard, users can precisely select high-quality cleanroom wipes tailored to specific cleanroom scenarios, effectively reducing contamination risks, extending equipment lifetime, improving process yield, and enhancing product reliability, thereby supporting sustained growth in high-cleanliness industries.

High-Level Cleanroom Wipes: Analysis & Guidance

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In cleanroom management, selecting the appropriate cleanroom wiping materials is crucial for maintaining production environment quality and improving product yield. Cleanroom wipes (also called cleanroom nonwoven wipes) and cleanroom cloths are often confused, but there are significant differences in key performance and application scenarios between the two. So, can cleanroom wipes be used for wiping in high-level cleanrooms? This article analyzes the differences from the perspectives of edge-sealing technology, contamination control indicators, and cleanroom class compatibility, and provides professional recommendations.

1. Key Reasons Why Cleanroom Wipes Are Not Recommended for High-Level Cleanrooms

  • Edge Sealing Technology Differences and Potential Contamination

    • Cleanroom wipes generally use cold-cut edge sealing, resulting in relatively rough edges that tend to shed fibers during use, becoming uncontrolled particulate contamination sources in the cleanroom.

    • Cleanroom cloths adopt laser or ultrasonic edge sealing technology that creates a highly fused and smooth edge, greatly reducing or eliminating fiber shedding, meeting the stringent cleanliness requirements of high-level cleanrooms.

  • Differences in Contamination Control Indicators

    • Although some cleanroom wipes are manufactured in Class 10,000 environments (such as those by top brands), their production and post-processing generally lack the rigorous deep cleaning processes required for high-level cleanrooms. This means they may carry and release non-volatile residues (NVR), liquid particle counts (LPC), and ionic contaminants (such as sodium, potassium, chloride), which can directly affect precision manufacturing and electronic components.

    • Cleanroom cloths are specifically designed for high cleanliness, undergoing multiple ultrapure water washes and strict testing. Their NVR, LPC, and ion levels meet or exceed ISO Class 5 (Class 100) and higher standards. Some manufacturers offer up to Class 10 cleanroom cloths, widely used in advanced semiconductor manufacturing.

2. Cleanroom Class Compatibility

  • Cleanroom wipes are suitable for lower-level cleanrooms such as Class 10,000 and Class 100,000, as well as peripheral cleanroom areas (equipment exteriors, floors), where particle and chemical contamination control requirements are more lenient.

  • Cleanroom cloths are essential consumables for core areas in high-level cleanrooms (Class 100, Class 10, and above), suitable for direct contact with precision instruments, optical components, semiconductor wafers, and sterile pharmaceutical production equipment, ensuring that wiping does not introduce contamination risks.

3. Conclusion and Recommendations

  • Use cleanroom wipes only in lower-class cleanrooms or non-critical areas of high-level cleanrooms (such as equipment housing and floors) to leverage their cost-effectiveness.

  • Use cleanroom cloths exclusively in core process areas of high-level cleanrooms. Their superior edge sealing and stringent contamination control (low NVR, LPC, and ionic contamination) are fundamental to maintaining ultra-clean environments and protecting high-value products and processes.

  • Never substitute cleanroom wipes for cleanroom cloths in critical high-level cleanroom operations. When procuring, require suppliers to provide full cleanliness certification and contaminant test reports (NVR, LPC, Ions) to ensure product performance matches the cleanroom standards.

Properly distinguishing between cleanroom wipes and cloths by application scenario is the foundation for maintaining cleanroom operation efficiency and product quality. Selecting the right wiping materials minimizes contamination risks and supports the stable development of high-end manufacturing processes.

Cleanroom Wipes: Contamination Removal Analysis

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In industries with stringent cleanliness requirements, cleanroom wipes serve as essential cleaning tools whose performance directly impacts production efficiency and product quality. This article analyzes the technical advantages of cleanroom wipes in contaminant removal from five core performance dimensions:

  1. Rapid Penetration and High Absorption Rate
    The fiber structure of cleanroom wipes determines their absorption capacity. Wipes made from 100% polyester fiber or microfiber (with fineness less than 1 denier) exhibit high porosity and capillary action, allowing quick penetration and absorption of liquids and contaminants. For example, microfiber diameter is only about 1/20 that of ordinary fibers, forming a dense network that significantly increases absorption speed (up to 7-10 times faster than conventional fabrics). This feature is critical in semiconductor manufacturing, where spills of solvents like isopropanol (IPA) can be absorbed within seconds, preventing contamination of sensitive components.

  2. Contaminant Trapping and Retention Mechanisms
    Cleanroom wipes achieve efficient contaminant capture through two main mechanisms:

  • Physical Trapping: The microfiber weave forms microscopic “traps” that capture particles as small as 0.1 μm, such as metal debris and dust. For instance, in optical lens cleaning, wipes lock abrasive residues in fiber gaps, avoiding secondary scratches.

  • Chemical Adsorption: Some wipes undergo hydrophilic treatment (e.g., 18MΩ ultra-pure CDI cleaning), adding polar groups on fiber surfaces that attract charged ionic contaminants like metal ions. This capability effectively removes photoresist residues during LCD panel manufacturing.

  1. Enhanced Surface Adhesion (Stickiness)
    The adsorption force of cleanroom wipes derives from:

  • Fiber Morphology: Microfibers have a larger specific surface area, increasing contact with contaminants by 30%-50% and enhancing physical adsorption.

  • Surface Modification Techniques: Plasma treatments or coatings (such as polyurethane) provide directional adhesion. For example, antimicrobial wipes used in healthcare contain silver ions on fiber surfaces that not only trap soils but also inhibit bacterial regrowth during surgical instrument cleaning.

  1. Ultrafine Fiber Fineness and Precision Wiping Compatibility
    Microfibers finer than 1 denier (e.g., 0.5 denier) offer the following benefits:

  • Low Particle Generation: Finer fibers generate fewer particles during friction, meeting ISO Class 5 cleanroom standards.

  • Surface Conformity: Thin fibers penetrate complex structures (like tiny PCB holes), enabling blind spot cleaning. In automotive electronics assembly, such wipes remove conductive dust in connector gaps, preventing short circuits.

  1. Stability of Contaminant Retention on Wipes
    Cleanroom wipes are designed to minimize contaminant shedding:

  • Edge Sealing: Laser-fused or ultrasonic welding eliminates fiber fraying and loose ends, reducing lint by over 90%. Aerospace wipes, for example, withstand high-frequency wiping without shedding.

  • Composite Structures: Some wipes feature dual-layer fibers (hydrophobic outer, hydrophilic inner), where contaminants are locked in the inner layer by capillary forces, preventing secondary contamination. This design meets FDA food safety standards for safely removing oily residues in food processing.

  1. Application Scenarios and Performance Validation

  • Electronics Manufacturing: Using microfiber wipes with IPA after wafer polishing reduces surface particle count from 10^3 particles/cm² to below 10 particles/cm².

  • Medical Sterilization: Sterile wipes reduce microbial residue by 99.9% on surgical instruments.

  • Optical Instruments: Tests by lens manufacturers show anti-static wipes limit light transmittance loss to less than 0.1%.

Conclusion:
The wiping performance of cleanroom wipes integrates material science, process technology, and application requirements. Innovations such as nanofiber technology and intelligent surface treatments will further enhance contaminant removal efficiency. Future developments may include pH-responsive adaptive cleaning materials and “smart wipes” with integrated sensors to monitor cleaning effectiveness in real time. These advances will elevate clean environment management in cutting-edge fields like semiconductors and biomedicine.

7 Cleanroom Wiping Mistakes & Solutions

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Using cleanroom wipes for wiping is a crucial part of maintaining cleanliness in cleanroom environments. However, many organizations fall into common mistakes that not only reduce cleaning effectiveness but can also cause contamination to spread. This article thoroughly analyzes the seven common mistakes when wiping cleanrooms with cleanroom wipes and offers practical solutions to help cleanroom managers improve cleaning efficiency and product quality.

  1. Neglecting the Necessity of Regular Wiping
    Cleanrooms and controlled environments require daily cleaning and maintenance using cleanroom wipes to prevent contaminant buildup. Contaminants generally fall into two categories: film-like residues and particulate contaminants, both of which can cause critical defects in microelectronics. Failure to clean regularly decreases cleanliness levels and leads to costly downtime and increased production costs. For example, in a Class 100 cleanroom, work areas should be wiped every shift, walls and corners thoroughly cleaned weekly, and other maintenance tasks performed as scheduled—skipping these increases particle accumulation.

  2. Using Unfolded, Flat Cleanroom Wipes
    Using cleanroom wipes unfolded wastes material and risks spreading contaminants rather than removing them. The correct method is to fold the wipe twice, forming a quarter size, which provides multiple clean surfaces and increases cleaning efficiency. Used wipes should be discarded according to protocols to avoid recontamination.

  3. Using One Wipe for an Entire Area
    A single cleanroom wipe, properly folded, provides approximately eight clean surfaces—each surface should be used only once. Using a contaminated surface further spreads contaminants. Wiping should be performed in one direction with 10%-25% overlap. After each use, flip the wipe to a clean surface. Prepare sufficient wipes to thoroughly clean the entire area.

  4. Wiping From Dirty/Wet Areas Toward Clean/Dry Areas
    Wiping in cleanrooms must follow a “clean to dirty” progression to avoid dragging contaminants into clean areas. Large spills or contamination should first be isolated and controlled using cleanroom-specific absorbent materials before wiping with cleanroom wipes, ensuring contaminants do not spread.

  5. Wiping in Circular Motions
    Wiping in circles disperses particles over a wider area, damaging the cleanroom environment. The correct approach is to apply firm, even pressure and wipe in straight, single-direction strokes with about 10% overlap, flipping the wipe to a clean surface after each pass.

  6. Using Wipes That Are Too Dry or Too Wet
    Dry wipes can capture some particles but achieve best results when slightly dampened. Overly wet wipes leave dirty residues, causing rework and wasted time. Depending on cleanroom grade and scale, choose either dry wipes used with a separate cleaning agent or pre-moistened wipes. When using dry wipes with cleaning agents, avoid direct contact between the bottle and wipe to minimize cross-contamination.

  7. Using Wipes Unsuitable for the Cleanroom Grade
    Different cleanroom grades require specific cleanroom wipe standards—for example, semiconductor industries typically require Class 100 or Class 10 wipes. Using inappropriate wipes compromises cleanliness and introduces risks. Select wipes that comply with industry standards and regulatory requirements tailored to your application.

Summary:
Proper use of cleanroom wipes is essential not only for cleaning efficiency but also for ensuring product quality and production safety. Avoiding these seven common mistakes and following standard operating procedures can effectively reduce contamination risk, extend cleanroom equipment life, and improve production stability and compliance.

Cleanroom Wipes: Reuse Feasibility & Management

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Cleanroom wipes are essential cleaning tools widely used in semiconductor, pharmaceutical, optical, and precision manufacturing industries. Their core function is to maintain cleanliness by efficiently capturing particles and providing anti-static performance. However, with increasing cost-control pressures, many factories are exploring the feasibility of reusing and cleaning cleanroom wipes. This article combines industry practices and technical analysis to discuss the challenges, alternative solutions, and best management practices for cleanroom wipe reuse, helping enterprises make informed decisions.

1. Major Challenges in Reusing Cleanroom Wipes

1. Uncertainty in Contamination Levels
Cleanroom wipes accumulate different types and concentrations of contaminants depending on their use:

  • In semiconductor manufacturing, wipes may come into contact with high-purity solvents and acidic cleaners;

  • In pharmaceutical industries, they may be contaminated with biologically active substances.
    These contaminants are often difficult to fully remove through standard cleaning, leading to inconsistent cleanliness levels in reused wipes.
    Moreover, wipes from the same batch can have vastly different contamination levels, and a uniform cleaning process may over-clean lightly soiled wipes causing damage or leave harmful residues on heavily soiled ones, increasing cross-contamination risk.

2. Complexity and High Cost of Cleaning Processes
Cleaning cleanroom wipes requires a high-purity environment, strict control of water quality (typically deionized water), temperature, and cleaning agent concentration, and significant investment in specialized cleaning and drying equipment with ongoing maintenance costs.
Personnel must be trained in classification, cleaning parameters, and quality testing procedures.
Post-cleaning verification via particle counting and fiber shedding tests requires expensive and complex instruments, posing a burden especially for small and medium-sized enterprises.

3. Resource and Compliance Trade-offs
Although reuse can reduce direct procurement costs, hidden costs must be considered:

  • Time costs for collection, sorting, cleaning, and testing;

  • Opportunity costs as resources allocated to wipe recycling may detract from core R&D or equipment upgrades;

  • Compliance risks, as some industries (e.g., medical devices) may not accept reused wipes under regulatory standards.

2. Viable Alternatives and Optimization Strategies

1. Tiered Usage Strategy

  • Use disposable wipes in high-cleanliness zones (e.g., ISO Class 4-5 cleanrooms);

  • Use recycled wipes in lower-cleanliness areas (e.g., ISO Class 8-9 zones) for cleaning equipment exteriors or non-critical surfaces.

  • Employ pre-moistened wipes to reduce cleaning requirements; these are pre-soaked in isopropanol or deionized water and disposed of after use to avoid secondary contamination.

2. Selecting Durable and Reusable Materials

  • Some polyester microfiber wipes can be professionally cleaned and reused 3-5 times, with strict cleanliness monitoring;

  • Laser-cut edge wipes minimize fiber shedding and enhance durability for multiple washes.

3. Outsourcing Professional Cleaning Services

  • Partner with cleanroom service providers offering standardized automated cleaning and ISO-certified testing to ensure quality;

  • Scale economies reduce per-use costs and transfer contamination risks outside the company.

3. Best Practices for Cleanroom Wipe Management

1. Establish Clear Usage Protocols

  • Define use cases, replacement frequency, and discard criteria (e.g., replace wipe after wiping each wafer to avoid cross-contamination);

  • Provide regular employee training on proper unpacking, use, and disposal methods.

2. Optimize Inventory and Tracking

  • Procure wipes in various formats (rolls, cut sheets) based on demand to avoid overstocking;

  • Utilize barcode or RFID tracking to monitor usage cycles and cleaning history for traceability.

3. Monitor Technological Innovations

  • Incorporate antimicrobial fibers or biodegradable materials to reduce long-term costs and environmental impact;

  • Explore dry wiping technologies to minimize liquid cleaner dependency and extend wipe lifespan.

4. Conclusion

Technically, reusing and cleaning cleanroom wipes is feasible but requires balancing cost, risk, and benefit. For most enterprises, cleaning costs may exceed new wipe procurement costs. A pragmatic approach is to prioritize disposable wipes combined with tiered usage and outsourced cleaning services. Advances in cleanliness technology may bring more cost-effective reusable solutions in the future. Enterprises should tailor their wipe management strategies based on industry specifics, cleanliness requirements, and budget to achieve an optimal balance of quality, cost, and sustainability.