Why LCD Panel Production Requires a Clean, Dust-Free Environment？

Cleanliness is not a luxury in LCD manufacturing—it is a core requirement. Producing high-quality TFT-LCD and industrial display panels depends on a strictly controlled, dust-free environment, which is why cleanrooms are indispensable facilities in the display industry.

A cleanroom is far more than simply "a clean space." Under the International Organization for Standardization (ISO), it has a precise definition: a room in which the concentration of airborne particles is controlled, and which is constructed and used to minimize the introduction, generation, and retention of particles inside. Cleanrooms also regulate other critical parameters, including air pressure, temperature, and humidity.

Why so strict? In LCD production, even tiny contaminants—especially particles of 1 micron or smaller—can cause functional loss or shorten the shelf life of finished products. By maintaining strict hygienic conditions in processing areas and eliminating dust, particles, and microorganisms from the air, cleanrooms directly improve product quality and enable efficient, high-yield production.

Cleanroom Classification: From ISO 9 to ISO 1

Cleanliness levels are defined by the maximum number of particles allowed per unit volume of air. ISO Class 1 represents the highest level of cleanliness, while ISO Class 9 is the lowest. To put this in perspective:

• In a typical urban environment, outdoor air may contain up to 35,000,000 particles of 0.5 μm or larger per cubic meter—comparable to an ISO Class 9 cleanroom.
• By contrast, an ISO Class 1 cleanroom permits only 12 particles of 0.3 μm or smaller per cubic meter.

Key Requirements: Filtration and Pressurization

An effective air filtration system is the cornerstone of a fully operational cleanroom:

• Pre-filters remove dirt and dust visible to the naked eye.
• HEPA filters capture invisible micro-particles.
• Pressurized airflow keeps contaminants out: air is introduced through the ceiling, passing through fan-driven HEPA filters to create positive pressure inside the room. This higher pressure pushes airborne pollutants out through vents located at the lower part of the walls.

To appreciate the scale of cleanroom air purification: the entire air volume is replaced and purified more than once every minute.