How to choose the illuminance and light source of a cleanroom?
With the rapid development of scientific skills in industrial production, new skills, new technologies, and new products continue to emerge, and construction projects that require clean production environments continue to increase. Now, clean technology has been widely used in major sectors such as microelectronics, biopharmaceuticals, surgical medical care, and precision instrument manufacturing.
Cleanrooms are usually closed workshops with large grids, large spans and no daylighting windows. The "Code for Design of Cleanrooms" GB50073-2001 clearly stipulates the illuminance value of daylighting window cleanrooms. It is common for mixed lighting in clean areas without daylighting windows. The lighting is not lower than 2001x, which is one level better than the 1501x in GBJ73-84. The illuminance specifications of artificial lighting in China are lower than those in Europe, the United States and other countries. In fact, the illuminance of some Sino-foreign joint ventures and wholly foreign-owned clean factories is much higher than 2001x. , Reaching 300~5001x. For operators working in a closed cleanroom, providing them with a bright and comfortable visual environment can greatly improve the production power and the yield of precision products. Therefore, it is beneficial to properly improve the artificial lighting illuminance level of the cleanroom, improve the visual cleanliness of the staff, and promote the development of the national economy.
The illuminance of different cleanrooms is different according to the technical requirements. For example, the illuminance of the mixed lighting of the electron gun assembly workshop of the picture tube factory must reach 1000~30001x. In addition to the normal lighting, it is also necessary to set up partial lighting and partial lighting mixed. The share of lighting illuminance cannot be too large, usually 5~15% of mixed lighting. China has expanded the illuminance share of some lighting in mixed lighting due to the shortage of electricity. If the space illuminance is low, it is easy to produce glare and make people feel tired, but the brightness of the light source should not be too high, often choose fluorescent lamps and other wire-mounted light sources or incandescent lamps with frosted glass.
Secondly, in cleanrooms that have special requirements for light sources, such as the phosphor coating room in the kinescope factory and the lithography room in the semiconductor factory, in order to prevent the photosensitive material from being exposed to light, yellow or red light sources must be used, which should be satisfied. For special requests, use yellow fluorescent tubes or low-pressure sodium lamps. There are also two types of yellow fluorescent tubes. One is coated with yellow phosphor on the inner wall of the tube; the other is white fluorescent tubes with yellow plastic sleeves. Their luminous flux is lower than that of ordinary fluorescent lamps.