Do you know what is a cleanroom?

2023-10-23

original

Marya

A cleanroom is an engineering space that maintains a very low concentration of particulate matter in the air. It is well isolated, pollution is well controlled, and actively cleaned. The cleanroom aims to keep everything from dust to biological or vaporized particles in the air away from it, and thus from any materials being processed inside.

A cleanroom is an engineering space that maintains a very low concentration of particulate matter in the air. It is well isolated, pollution is well controlled, and actively cleaned. These rooms are typically used for scientific research and industrial production of all nanoscale processes, such as semiconductor manufacturing. The cleanroom aims to keep everything from dust to biological or vaporized particles in the air away from it, and thus from any materials being processed inside.
On the contrary, a cleanroom can also help prevent materials from overflowing from it. This is usually the main goal of hazardous biology and nuclear work, pharmacy, and virology.
Cleanrooms typically have a cleanliness level that is quantified by the number of particles per cubic meter measured by predetermined molecules. The outdoor ambient air in typical urban areas contains 3500000 particles per cubic meter, with a size range of 0.5 μ M or greater, equivalent to an ISO 9 certified cleanroom. In contrast, ISO 14644-1 Class 1 certified cleanrooms do not allow the generation of particles within this size range, at 0.3 per cubic meter μ M and smaller, only 12 particles are allowed. Semiconductor facilities typically operate at level 7, while level 1 facilities are very rare.

1. Overview of Marya Cleanroom

Cleanrooms are a necessity in semiconductor manufacturing, rechargeable battery industry, life sciences, and any other highly sensitive field to environmental pollution.
The range of cleanrooms can range from very small to very large. On the one hand, a single user laboratory can be built according to a cleanroom standard of a few square meters, and on the other hand, the entire manufacturing facility can be included in a cleanroom covering thousands of square meters on the factory floor. Between large and small, there is also a modular cleanroom. Some people believe that they have reduced the cost of expanding technology and are less susceptible to catastrophic failures.
In such a wide range of applications, not every cleanroom is the same. For example, the rooms used in semiconductor manufacturing do not need to be sterile (i.e. there are no uncontrolled microorganisms); And the ones used in biotechnology usually have to be. On the contrary, those used in biotechnology do not require absolutely pure nanoscale inorganic salts, such as rust, while nanotechnology absolutely requires it. Therefore, the common feature of all cleanrooms is strict control of particulate matter in the air, which may result in secondary purification of the air, surfaces, workers entering the room, tools, chemicals, and machinery. Sometimes, particles leaving the compartment are also worth paying attention to, such as in research on dangerous viruses or in places where radioactive materials are handled.

2. Basic Structure of Clean room

Firstly, the external air entering the cleanroom is filtered and cooled by several outdoor air processors using gradually finer filters to remove dust.
Internally, air is continuously recirculated through fan units containing high-efficiency particulate air filters (HEPA) and/or ultra-low particulate air (ULPA) filters to remove internally generated pollutants. Use special lighting fixtures, walls, equipment, and other materials to minimize the generation of particulate matter in the air. If the cleanroom is designed for laminar airflow, plastic sheets can be used to limit air turbulence.
The air temperature and humidity levels in cleanrooms are strictly controlled as they affect the efficiency and means of air filtration. If a specific room requires sufficient low humidity to make static electricity a problem, it will also be controlled by, for example, using corona discharge to introduce a controlled amount of charged ions into the air. Electrostatic discharge is particularly concerning in the electronics industry as it can immediately damage components and circuits.

Any cleanroom equipment is designed to generate minimal air pollution. The selection of materials used for building cleanrooms should not produce any particles, therefore single piece epoxy resin or polyurethane floor coatings are preferred. Use polished stainless steel or powder coated low-carbon steel sandwich wall panels and ceilings instead of iron alloys that are prone to rusting and peeling off. By providing groove surfaces, corners such as wall to wall, wall to floor, and wall to ceiling are avoided, and all joints need to be sealed with epoxy sealant to avoid sedimentation or particle formation at the joints through vibration and friction.

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