Clean Room Definition And Classifications For Clean Rooms

Dust-free workshop clean level generally divided into 100 grade, 1000 grade, 10000 grade, 100000 grade, 2010 edition of GMP purification workshop has now don't have to call this, divided into ABCD level, respectively corresponding to the 98 version of several levels, by detecting area number, number of planktonic bacteria, dust particle mean evaluation level of purification, at all levels have different requirements, purification are rated static and dynamic two kinds.

(1) Clean Room Definition

A clean room is a specially designed room in which the air particles, harmful air, bacteria and other pollutants are removed from the air within a certain space range, and the indoor temperature, cleanliness, indoor pressure, airflow velocity and airflow distribution, noise, vibration, lighting and static electricity are controlled within a certain demand range. That is, no matter how the external air conditions change, its indoor can have to maintain the original set requirements of cleanliness, temperature and humidity and pressure performance characteristics.

The main function of the clean room is to control the clean life and temperature and humidity of the atmosphere in which the products (such as silicon chips, etc.) are exposed, so that the products can be produced and manufactured in a good environmental space, which we call the clean room.

(2) The Grade Of Clean Room

there are self-determined standards in all countries in the world, but the federal standard of the United States is 209. The standards of 209D and 209E are introduced and compared with those of other countries in the world.

The big difference between 209E and 209D is that 209E is a metric unit, and the clean room rating is marked with "M", such as M1, M1.5, M2.5, M3... . Thus, in line with the standardization of national metric units, the Arabic numerals after the M letter are >=0.5 per cubic meter in the Arabic numerals of the dust particles of the >=0.5 per cubic meter in the Arabic numerals of the dust particles of the >=0.5 per cubic meter in the Arabic numerals of the dust particles of the >=0.5 per cubic meter in the Arabic numerals of the dust particles of the >=0.5 per cubic meter in the Arabic numerals of the dust particles of the >=0.5 per cubic meter in the Arabic numerals of the dust particles of the >=0.5 per cubic meter. 

The United States federal standard FS 209D is measured in inches per cubic foot, while Japan USES the metric system, measuring 0.1 microparticles per cubic meter. The Japanese standard notation is Class 1, Class 2, Class 3... Class8 means that the good grade is Class 1 and the difference is Class8, which is obtained by taking the total number of dust particles per cubic meter to a power of 10.

(3) Items Under Clean Room Control

1. Can remove the floating dust particles in the air. 2. Can prevent the generation of dust particles. 3. Temperature and humidity control. 4. Pressure regulation. 5. Elimination of harmful gases. 6. Air tightness of structure and compartment. 7. Prevention of static electricity. 8. Electromagnetic interference prevention. 9. Safety considerations. 10. Consideration of energy conservation.

(4) Clean Room Classifications

1. Turbulent Flow: air enters the clean room from the air conditioning box through the air duct and the clean room air filter (HEPA), and is returned by the wall panel or elevated floor of the two compartments of the clean room. The flow is not linear and shows irregular turbulence or eddy current. This type is suitable for clean room class 1000-100,000.

Advantages: simple structure, cost of system construction, easy expansion of clean room, clean room grade can be improved by clean bench in some special use places.

Disadvantages: the dust particles caused by turbulence floating in the indoor space are not easy to discharge, easy to pollute the process products. In addition, if the system is shut down and reactivated, it often takes quite a long time to achieve the required cleanliness.

2. Laminar (Laminar) : Laminar air flows ina uniform linear form. Air enters the room through a 100% coverage filter and is returned by a raised floor or two side wall panels. This type is suitable for use in environments where the clean room grade is higher than Class 1 to Class 100. There are two types:

(1) horizontal layer flow: the horizontal air is blown out of the filter in one direction, and the dust is discharged out of the room by the return air system on the opposite wall. Generally, the pollution is serious on the downstream side.

Advantages: simple structure, stable in a short time after operation.

Disadvantages: the construction cost is higher than the turbulence, the interior space is not easy to expand.

(2) vertical layer flow: the ceiling of the room is completely covered with ULPA filter, and the air is blown down from the top to the bottom to obtain a high degree of cleanliness. The dust generated by the process or workers can be quickly discharged from the outside without affecting other working areas.

Advantages: easy to manage, stable state can be achieved in a short time at the beginning of operation, not easy to be affected by operation state or operation personnel.

Disadvantages: the construction cost is high, the flexibility of the use of space is difficult, the ceiling hangers take up a lot of space, maintenance and replacement of filters more trouble.

3. Mixed Type: the Mixed Type is used to compound or combine the chaotic flow and stratified flow to provide partial ultra-clean air.

(1) Clean Tunnel: 100% coverage of the process area or working area with a HEPA or ULPA filter can increase the cleanliness level to more than 10, which can save the installation and operation costs. This type, which is used in most ULSI processes, isolates the working area of the operator from product and machine maintenance to avoid affecting work and quality during machine maintenance.

Clean tunnel has two other advantages: a. easy elastic expansion; B. Easy to perform in the maintenance area when repairing equipment.

(2) Clean Tube: encircle and purify the automatic production line through which the product flows, and raise the cleanliness level above 100. Due to the isolation between the product, the operator and the dust environment, a small amount of air supply can get a good cleanliness, can save energy, no manual production line is suitable for use. Applicable to the pharmaceutical, food and semiconductor industries.

(3) install local Clean Spot: improve the cleanliness level of the product process area in the Clean room with the Clean room grade of 10,000~100,000 turbulence to more than 10~1000 for the purpose of production; Clean work table, clean work shed, clean air ark belongs to this kind namely.

Clean workbench: grade Class 1~100.

Clean work shed: for in the disorderly flow of clean room space in case of electrostatic transparent plastic round into a small space, use HEPA and ULPA or air conditioning air supply unit and a higher level of clean room, the level of 10 ~ 1000, height 2.5 meters, under the covering area of about 10 m2, with four pillars and wheel equipped with activity, can be use for the elastic.