In the precision-demanding fields of PCB manufacturing and electronics, the choice of cleanroom wipes directly influences product quality and production environment cleanliness. This guide provides an in-depth overview of how to select and properly use cleanroom wipes specifically for PCB circuit board cleaning, covering material selection, edge finishing, size, cleanliness level, and practical usage tips.

1. Cleanroom Wipe Selection Guide

Material Selection:

• Polyester Fiber: Most standard cleanroom wipes use 100% polyester double-knit fabric. This material offers a soft surface with low fiber shedding due to friction, suitable for general PCB cleaning tasks.

• Ultrafine Fiber: Made from 80% polyester and 20% nylon blend, ultrafine wipes provide superior liquid absorption and are ideal for precision cleaning tasks such as chips and microprocessors, effectively removing fine particles.

Edge Finishing:

• Laser Edge Sealing: Uses high-temperature fusion to melt fibers, reducing lint generation. Edges are relatively rigid but ensure high cleanliness, fitting most PCB cleaning scenarios.

• Ultrasonic Edge Sealing: Offers softer edges, better for highly sensitive surfaces like optical components, though at a higher cost.

• Avoid Raw Cut Edges: Unsealed wipes tend to shed lint, posing risk of secondary contamination.

Basis Weight and Size:

• Basis Weight: Polyester wipes with ≥120g/m² balance absorption and durability. Ultrafine wipes with ≥120g/m² are also recommended for enhanced performance.

• Size: Common sizes include 4″×4″, 6″×6″, and 9″×9″. Larger wipes (9″) suit broad surface cleaning, while smaller sizes are better for delicate or confined areas. The 9″ size is widely used.

Cleanliness Grade:

• Choose wipes based on the production environment’s cleanroom class. For example, Class 100 cleanrooms require Class 100 cleanroom wipes.

Additional Features:

• Anti-Static: Wipes with anti-static properties (often achieved via conductive fibers) prevent static buildup and dust attraction, safeguarding PCB performance. For less stringent needs, solvent-wetting can reduce static.

• Pre-Wetted Options: Some wipes come pre-impregnated with alcohol (e.g., IPA), reducing on-site spraying. More common internationally than domestically.

2. Proper Usage of Cleanroom Wipes

Pre-Wetting:

• Use high-purity solvents such as ≥99% isopropyl alcohol (IPA) or ethanol.

• Ensure uniform wetting via controlled soaking devices to avoid overly wet or dry spots.

Unpacking Procedures:

• Perform unpacking in Class 1000 or higher cleanroom environments, wearing cleanroom garments, gloves, and masks.

• Wipe the outer packaging opening with a cleanroom wipe moistened with solvent to prevent external contamination.

Wiping Techniques:

• Fold wipes to enclose edges internally, preventing lint from edges contacting PCB surfaces—especially important for ultrasonic sealed wipes which can be abrasive.

• Use unidirectional wiping with light, consistent pressure to avoid redeposition of particles or surface scratching.

• Adjust wiping force according to PCB surface sensitivity, with extra care on pads or sensitive areas.

Solvent Use:

• Apply enough solvent to moisten the wipe without dripping to avoid residue from evaporation.

• Test new solvents on small PCB areas first to confirm compatibility and avoid corrosion.

Storage and Reuse:

• Seal unused wipes immediately to prevent dust absorption.

• High-end wipes may be reused after cleaning with ultrapure water (18 MΩ·cm) and drying in a cleanroom; ordinary wipes are generally single-use.

3. Important Precautions

• Wear anti-static wristbands and ensure grounded workstations to prevent ESD damage to components.

• Avoid wiping multiple areas with the same wipe to reduce cross-contamination risks.

• Regularly monitor cleanroom temperature and humidity.

4. Recommended Brands and Models

• Brands: Preferably YUSTER (domestic) or TEXWIPE (international).

• Models:

  • K122 Series: 120g basis weight, laser or ultrasonic sealed edges, suitable for PCB boards and applications involving liquids. Available in four sizes.

  • K610 Series: 180g basis weight ultrafine fiber with laser or ultrasonic sealing, excellent absorption for high-precision cleaning.

Summary

For budget-conscious scenarios, 120g laser-cut polyester wipes provide reliable cleaning. For higher requirements and budgets, 180g laser-cut ultrafine fiber wipes offer enhanced absorption and gentler cleaning for delicate PCB surfaces.