According to international practice, the dust-free purification level is mainly specified according to the number of particles whose particle diameter is larger than the division standard in each cubic meter of air. That is to say, the so-called dust-free is not 100% without a little dust, but controlled in a very small unit. Of course, the particles that meet the dust standard in this standard are already very small compared to our common dust, but for optical structures, even a little bit of dust will have a very large negative impact, so in the production of optical structure products , dust-free is an inevitable requirement.

Controlling the number of fine dust particles less than 0.5 micron in size per cubic meter to less than 3,500 has reached Class A of the international dust-free standard. The dust-free standards currently applied in chip-level production and processing have higher requirements for dust than grade A. Such high standards are mainly used in the production of some higher-level chips. The amount of fine dust is strictly controlled within 1000 per cubic meter, which is commonly known as the 1K level in the industry.

The following are the purification parameters that need to be known in the clean room:

1. Compartment, ceiling material, ceiling height;

2. Floor material;

3. Whether the temperature and humidity are constant;

4. Is exhaust ventilation required?

5. The total number of people in the workshop;

6. The calorific value of the process equipment in the workshop;

Wait for a series of parameters.

The standards for a 100,000-level dust-free workshop are:

The maximum allowable amount of dust (per cubic meter);

The number of particles greater than or equal to 0.5 microns shall not exceed 3,500,000, and the number of particles greater than or equal to 5 microns shall not exceed 20,000;

The maximum allowable number of microorganisms;

The number of planktonic bacteria shall not exceed 500 per cubic meter;

The number of settled bacteria shall not exceed 10 per petri dish.

Pressure difference: The pressure difference between clean rooms of the same cleanliness level is consistent. The pressure difference between adjacent clean rooms of different cleanliness levels must be ≥ 5Pa, and the pressure difference between clean rooms and non-clean rooms must be ≥ 10Pa.

When the 100,000-level dust-free workshop has no special requirements on temperature and humidity, it is better to wear clean work clothes without feeling comfortable. The temperature is generally controlled at 20~22°C in winter and 24~26°C in summer; fluctuation ±2°C. The humidity of the clean room is controlled at 30-50% in winter and 50-70% in summer.

Power distribution: The general illuminance value of the main production room in the clean room (area) should be ≥ 300Lx; the illuminance value of the auxiliary studio, personnel purification and material purification room, airlock room, corridor, etc. should be 200~300Lx.

noise control

1. During the dynamic test, the noise level in the 10,000-class clean room should not exceed 70 decibels.

2. During the static test, the noise level of the 10,000-class turbulent flow clean room should not be greater than 60 decibels A.

Airflow organization

The air supply method mainly used in the 100,000-class dust-free workshop;

1. Partial orifice ceiling air supply;

2. Ceiling air supply with high-efficiency air filter with diffuser plate;

3. There are three air supply methods such as upper side wall air supply.

The air return method mainly used in the 100,000-class dust-free workshop;

1. Arrange return air outlets at the lower part of the single side wall; 2. When using corridor return air, arrange return air outlets evenly in the corridor or centrally set return air outlets at the end of the corridor.

Air outlet wind speed m/s:

1. Orifice plate orifice 3~5;

2. Side air outlet:

(1) Attach jet 2~5;

(2) The return air of the non-attached jet is 1.5~2.5 at the lower part of the same side wall, and 1.0~1.5 at the lower part of the opposite side wall.

Wind speed at return air outlet (m/s):

1. The return air outlet of the clean room is not more than 2;

2. The return air outlet in the corridor is not more than 4.

Standard operating procedures for personnel entering and leaving the 100,000-level dust-free workshop

1. Purpose

Establish a standard operating procedure for the entry and exit of personnel in a 100,000-level clean room to ensure that the clean room is not polluted by personnel.

2. area

The entry and exit of personnel in the 100,000-level dust-free workshop of the workshop, including production operators, maintenance personnel and management personnel.

3 responsibility

3.1 All personnel entering and exiting the 100,000-class clean room shall be responsible for this operating procedure.

3.2 The clean room team leader and on-site quality control personnel are responsible for supervision and inspection.

4 content

4.1 After entering the door of the clean room, put down your rain gear and items in the specified position.

4.2 Change slippers. At the shoe changing place, sit on the shoe bench, take off your home shoes, put them in the shoe cabinet, turn them 180 degrees, and take out your own slippers on the upper shelf of the shoe cabinet to put them on.

4.3 Change of work clothes. Enter the general work area office, take off the employee's casual clothes and change into work clothes.

4.4 Wash your hands. Wash your hands according to the hand washing process.

4.5 Change work shoes. Enter the door of the shoe changing room, sit on a horizontal bench, face the door, take off the slippers, put the slippers in the lower shelf of the shoe cabinet, take out your work shoes from the upper shelf of the shoe cabinet, sit and turn them 180 degrees with your back facing the door, and put them on.

4.6 Wash hands and dry.

4.6.1 Wet hands with water in the sink to 10cm above the wrist, wash with detergent, make the skin of 10cm above the hand and wrist full of foam, and rub for about 15 seconds.

4.6.2 Rinse your hands with water, wash off the soaked rice on your hands, turn your hands up and down, and rub them until you don't feel greasy.

4.6.3 Visually check that hands are clean.

4.6.4 Extend the palm of the hand to 8~10cm below the hand dryer, and dry the hand until it is dry.

4.7 Change into clean underwear. Take off the work clothes and put them in the personal locker, and take off the work cap, work clothes and work pants with the personal number from the wall hook of a locker room and put them on. Put it on in order from top to bottom, that is: first put on the hat, then the mask, then the top, and then the pants. Pay attention to tie all the coats tightly into the trouser pockets, stuff all the hair into the caps, and check whether the caps are neat.

4.8 Wash hands and disinfect.

4.8.1 Wet hands with water in the sink to 10cm above the wrist, wash with detergent, make the skin of 10cm above the hand and wrist full of foam, and rub for about 15 seconds.

4.8.2 Rinse your hands with water, wash off the soaked rice on your hands, turn your hands up and down, and rub them until you don't feel greasy.

4.8.3 Visually check that hands are clean.

4.8.4 Disinfection. Soak your hands to 10cm above your wrist in chlorine-containing disinfectant for 30 seconds.

4.8.5 Extend the palm of the hand to 8~10cm below the hand dryer, and dry the hand until it is dry.

4.9 Wear coveralls. Take out the coverall with your personal number from the closet. Put it on in order from bottom to top, and be careful not to allow the coverall to touch the ground.

4.10 Disinfection. Push the door to enter the buffer room, put your hands under the automatic induction sprayer filled with 75% ethanol, spray for disinfection, shake your hands, and let the ethanol evaporate.

4.11 Enter the clean room. Open the door of the buffer room and enter the dust-free area.

4.12 Personnel leaving the clean area shall follow the reverse procedure of entering the clean area. Pay attention to undressing from bottom to top when dragging work clothes.

4.13 Outside visitors must be approved by the factory, and under the guidance and supervision of the workshop management personnel, enter and exit the clean room according to the prescribed procedures. Foreign visitors must strictly abide by the management regulations of the workshop dust-free. During the production period of the clean room, outside visitors are not allowed to enter.