ISO5 Hard Wall Cleanroom Clean Booth

Core Design Standards

1. Airflow Organization:

●A vertical unidirectional flow design must be adopted, with an FFU (Fan Filter Unit) coverage rate of ≥90%, ensuring uniform airflow coverage across the entire operating area and a stable flow velocity of 0.3–0.5 m/s.

●Airflow flows from top to bottom across the operating surface, carrying away suspended particles before being discharged from the bottom return air vent, avoiding localized eddies and preventing particle settling and product contamination.

2. Differential Pressure Control:

●The cleanroom must maintain a positive pressure of ≥10 Pa relative to the outside environment and ≥5 Pa relative to adjacent lower cleanliness areas to prevent the infiltration of external contaminants.

●A differential pressure sensor and pressure relief valve are standard, monitoring the differential pressure in real time and automatically adjusting it. An audible and visual alarm is triggered when data is abnormal.

3. Filtration System Configuration:

●The terminal filter must use a ULPA ultra-high efficiency filter (filtration efficiency ≥99.999%@0.12μm), not a regular HEPA filter, to meet the stringent requirements of ISO Class 5.

●A pre-filter and a medium-efficiency pre-filter need to be installed at the front end to extend the life of the ULPA filter. The pre-filter should be replaced every 1-2 months, the medium-efficiency filter every 3-6 months, and the ULPA filter has a lifespan of 1-2 years.

Essential Supporting Equipment

1.Personnel/Material Purification Equipment

●Personnel Entrance: Single-person double-air shower, airflow time 10–15s, air velocity ≥25m/s, ensuring dust is blown off clothing surfaces.

●Material Transfer: Laminar flow pass-through window with built-in small FFU, maintaining ISO 5 cleanliness within the pass-through window, equipped with an interlock device to prevent simultaneous opening of both doors.

2.Environmental Control Equipment

●Temperature and Humidity Control: Cleanroom-specific air conditioning (CRAC), temperature controlled at 22±2℃, humidity 40%–60% RH, with optional dehumidification/humidification modules.

●Static Electricity Elimination: Ion fans installed above workstations, balancing voltage ≤±10V, eliminating static electricity in real time to prevent static-induced particle adsorption or damage to precision components.

3.Maintenance Auxiliary Equipment

●Cleanroom-specific dust-free vacuum cleaner (HEPA filter grade), for daily cleaning; ordinary vacuum cleaners are prohibited.

●Particle Counter: Regularly checks cleanliness; weekly sampling is recommended to ensure long-term stable compliance.

Maintenance Precautions

●Wear a full set of cleanroom clothing (coverall, mask, gloves, and cleanroom shoes) before entering the cleanroom, and pass through an air shower before entering;

●Do not bring in dust-producing or dust-generating items. Handle items gently to avoid airflow disturbance; Regularly check the filter resistance.

●Replace the ULPA filter immediately when the resistance reaches twice the initial value.

Commonly used equipment in cleanrooms