TFT LCD display production process step 2 – Glass Cleaning – Purity for Performance

Purpose:

This process eliminates sub-micron dust particles, organic films, fingerprint lipids, ionic residues, and glass cullet from the substrate surfaces. Achieving pristine surface energy is absolutely critical; any remaining microscopic contaminant would cause localized electrical opens/shorts, cross-talk, or delamination during the subsequent thin-film lamination and high-density bonding phases.

Process Characteristics & Equipment:

Processing occurs inside an enclosed Class 100 (ISO 5) Cleanroom Module. Maxen deploys a Multi-Stage Inline Cleaning System comprising Ultrasonic Cavitation Baths (running at dual frequencies of 40kHz and 80kHz), High-Pressure DI (Deionized) Water Jet Sprayers, and inline Atmospheric Pressure Plasma Surface Treatment Systems (using an O₂/Ar gas mix). Surface cleanliness is quantified using Optical Contact Angle Goniometers and Particle Counters (e.g., Topcon surface defect analyzers).

• Purity Metrics: DI water resistivity is maintained strictly at >18.2 MΩ⋅cm at 25°C, keeping particle contamination to zero particles >0.3 μm per square centimeter.

Factory Processing Time:

The total pass-through cleaning, chemical rinsing, multi-stage DI water flushing, and final Hot Air Knife / Infrared Drying cycle takes 180 to 240 seconds, depending on line velocity.

Continuous Improvement (Kaizen) & Vision:

Maxen's green manufacturing initiative is optimizing the DI Water Closed-Loop Reclamation System to achieve a 92% water recycling rate. On the process side, engineering teams are auditing plasma power parameters to lower the water contact angle from its current 12° down to <3°. This micro-improvement maximizes chemical wetting and increases the subsequent film adhesion strength by 15%.