ISO 14644-1 Analysis: Does Your Cleanroom Qualified?

In the field of cleanroom projects, the international standard ISO 14644-1 is an important specification that cannot be avoided. It plays a key guiding role in many industries with extremely strict environmental requirements, such as chip manufacturing, vaccine production, and aerospace.

Cleanroom is a special space in which the particle concentration is strictly controlled. Through careful design, construction, and efficient operation and management, cleanrooms can minimize the introduction and retention of pollutants such as dust and microorganisms. The significance of the ISO 14644-1 standard lies in the establishment of a unified "cleanliness measurement scale" for different industries, thereby ensuring the controllability of the production environment.

The ISO 14644-1 standard divides air cleanliness into 9 levels in detail. Among them, ISO 1 represents the cleanest state, while ISO 9 is relatively the most relaxed. The core basis of this division is the number of particles with a particle size of ≥0.1μm to 5μm per unit volume.

When conducting sampling tests, the clean room will be divided into grids, and each grid will be set up with a sampling point to ensure that the entire clean room can be fully covered. The specific test process is mainly divided into the following five steps:

1. Instrument preparation: Use a dust particle counter as the test instrument, requiring its flow rate to reach ≥28.3 liters/minute, and the calibration accuracy must meet the relevant standards.

2. Sampling volume calculation: Use a specific formula to calculate the single sampling volume, that is, the single sampling volume (Vs) = 20/(concentration limit) × 1000.

3. Data collection: Place the probe vertically upward. When sampling in the unidirectional airflow area, ensure constant speed sampling to avoid particle loss due to improper sampling speed.

4. Processing of over-standard results: If the data of a certain sampling point is abnormal, it is necessary to investigate the reasons behind it in depth, such as whether there is equipment failure and other problems, and retest after finding out the cause.

5. Report generation: The final report must contain 10 core information including instrument model, sampling location, flow rate, particle concentration, etc., so as to achieve data traceability.

In addition, according to the requirements of ISO 14644-1 standard, when selecting appropriate particle counters and test equipment, multiple factors need to be considered comprehensively. For example, the clean room cleanliness level, the particle size range of the particles to be detected, the number of sampling points, and the specific sampling volume, etc., only in this way can the accuracy and reliability of the test results be ensured.