Class 100 cleanrooms (ISO Class 3)—critical for semiconductor, aerospace, and precision optics manufacturing—demand equipment maintenance that maintains ultra-low particle counts (≤100 particles ≥0.5μm per cubic foot) and avoids cross-contamination. Cleaning wet wipes—pre-moistened with high-purity solvents (99.9% IPA, deionized water) or sterile cleaners—are indispensable for this task. They eliminate manual solvent mixing risks (particle ingress, inconsistent concentration) and deliver targeted, residue-free cleaning for sensitive equipment. Below is their tailored application across key Class 100 equipment maintenance tasks.
1. Semiconductor Processing Tools: Wafer Chucks, Nozzles, and Chambers
Semiconductor tools (e.g., CVD/PVD chambers, etchers, lithography scanners) accumulate process residues (photoresist, metal oxides) and micro-particles that ruin wafers. Wet wipes ensure precise, non-abrasive cleaning:
- Wipe Selection: Use static-dissipative wet wipes (surface resistance: 10⁶–10¹⁰ Ω) pre-impregnated with 99.9% electronic-grade IPA (metal impurities ≤10 ppb) for metal components (wafer chucks, gas nozzles). For quartz parts (chamber liners), choose deionized water-based wipes to avoid quartz degradation.
- Application Steps:
- Power down the tool and purge chambers with nitrogen to reduce airborne particles.
- For wafer chucks: Fold wipes into 1cm-wide strips and clean vacuum holes with light pressure (<0.5 psi)—avoids clogging or scratching dielectric layers.
- For gas nozzles: Wrap wipes around plastic-tipped tweezers to clean internal channels—removes residue that disrupts uniform gas flow.
- Post-clean: Verify with a portable particle counter (target: ≤1 particle ≥0.1μm per ft²) to meet Class 100 standards.
2. Optical Inspection Equipment: Lenses, Sensors, and Stages
AOI (Automated Optical Inspection) systems, laser scanners, and interferometers rely on dust-free optics—even 0.1μm particles distort measurements. Wet wipes protect delicate optical components while ensuring purity:
- Wipe Selection: Opt for ultra-fine microfiber wet wipes (0.1μm diameter) pre-wet with lens-grade IPA or deionized water (low outgassing, meets SEMI C12 standards). Avoid larger wipes to prevent solvent contact with non-optical parts (e.g., sensor circuit boards).
- Application Steps:
- Cool optics to <30°C (prevents thermal shock from solvent) and disconnect power.
- For lenses: Dab gently with a folded wipe (single linear strokes, no circular motions) to remove oil/residue—follow with a dry optical wipe to blot excess solvent.
- For inspection stages: Wipe in radial strokes (center to edge) to capture particles—avoids pushing debris into stage rails (which cause alignment errors).
3. Material Handling Equipment: Vacuum Lifters, Wafer Carriers, and Gloves
Material handlers (used to transport wafers, optics, or micro-components) accumulate skin oils, dust, and transfer residues—contaminants that spread to critical parts. Wet wipes ensure safe, consistent cleaning:
- Wipe Selection: Use sterile, lint-free wet wipes pre-moistened with 70% IPA for rubber/gripper surfaces (vacuum lifters) and anti-static wet wipes for plastic wafer carriers (prevents static-attracted dust).
- Application Steps:
- Disassemble carriers (per manufacturer guidelines) to access internal slots.
- For grippers: Wipe in gentle back-and-forth strokes to remove oil—avoid scrubbing (wears down rubber).
- For carrier slots: Use wipe strips (guided by tweezers) to clean narrow gaps—removes particle buildup that scratches wafers.
- Air-dry fully (5–10 minutes) before reassembly—moisture attracts dust in Class 100 environments.
4. Environmental Control Equipment: HEPA Filters, Air Diffusers, and Sensors
HEPA filters, air diffusers, and particle sensors maintain Class 100 air quality—dust on these components reduces filtration efficiency or skews sensor readings. Wet wipes support proactive maintenance:
- Wipe Selection: Choose low-linting polyester wet wipes pre-wet with deionized water (avoids leaving residue on filters/sensors). For sensor lenses, use lens-safe wet wipes to prevent coating damage.
- Application Steps:
- Turn off air handlers before cleaning diffusers/filters.
- For diffusers: Wipe grilles in downward strokes to capture dust (avoids pushing particles into the cleanroom).
- For particle sensors: Dab sensor windows with a mini wet wipe—removes dust that causes false high-particle alerts.
Critical Advantages for Class 100 Cleanrooms
- Purity: Wet wipes are manufactured in ISO Class 5 facilities and sealed in nitrogen-flushed packaging—no particle ingress during storage.
- Consistency: Pre-moistened solvents ensure uniform cleaning, eliminating human error from manual dilution.
- Efficiency: Cut maintenance time by 40% vs. traditional rags + spray bottles—critical for minimizing tool downtime in high-volume production.
By integrating cleaning wet wipes into maintenance workflows, Class 100 cleanrooms preserve equipment performance, reduce product defects, and maintain compliance with the strictest purity standards—essential for manufacturing ultra-precision components.