Control method of static electricity in clean room

Clean room is an important part of industrial production, semiconductor, flat liquid crystal display, optoelectronics and biomedicine need clean production workshop, usually clean room refers to the space of airborne particles concentration is controlled within the specified boundaries of the room or limited space, the smaller the particle size of the dust particles and the smaller the number of limited particles, the higher the cleanliness. Static electricity for the clean room is undoubtedly a major hazard, mainly in electrostatic discharge, noise, electric shock and other hazards, how to control the static electricity of the clean room, become a top priority, the following by the anti-static information network summed up several clean room electrostatic control methods for your reference: 1, the basic principles of electrostatic control (1) determine the level of electrostatic control (2) minimize the generation of electrostatic charge (3) discharge and neutralization methods to accelerate the dissipation of electrostatic charge, Prevent electrostatic accumulation (4) Protect products from ESD damage 2, determine the level of electrostatic control (1) Components, components and equipment electrostatic sensitivity classification Level 1: susceptible to 0-1999V electrostatic voltage damage Level 2: susceptible to 2000-3999V electrostatic voltage damage Level 3: It is not necessary to take anti-static measures if the electrostatic voltage of 4000-5999V is damaged and the sensitive static voltage is greater than 16000V. (2) Classification of electrostatic protection work area Level A: The allowable electrostatic potential to the ground does not exceed ±100VB level: The allowable electrostatic potential to the ground does not exceed ±1000V In actual engineering, the electrostatic potential does not exceed 100V, 500V, 1000V and other corresponding components, components and equipment electrostatic sensitive voltage level 3. 3, as far as possible to reduce the generation of static charge this is the first step of the control of static electricity three steps, in this purification work environment, the best measures: (1) try to use similar properties of equipment, reduce the electrostatic charge generated in the process of contact friction separation; (2) Try to use electrostatic conductive or electrostatic dissipative materials to reduce the accumulation of static charge in the contact friction separation process; (3) Try to use a production process that reduces electrostatic charge generated by contact friction separation. 4, discharge and neutralization This is the second step of the three steps to control static electricity, the most common measure in the purification chamber of microelectronics production is grounding, the use of conductive or dissipative materials to discharge static charge, and the charge in the ionization dissipator. (1) An independent electrostatic grounding system (including ground grounding metal grid support system and production line workstation grounding support system) should be set up in the grounding clean room, so that the metal shell of all indoor equipment, metal supports of mobile equipment, anti-static equipment, etc., can safely and effectively release static charges to the earth. Electrifying personnel are grounded through wrist straps, and discharged to the ground through anti-static shoes or heel straps. Ground, wall, ceiling, partition, etc., are hard grounded, equipment shell, mobile equipment (cars, chairs, shelves, etc.), workbench, etc., are soft grounded. (2) The components, PCBS, production lines, and workstations assembled in the clean room of ionized electric appliances are always inevitable that there are some ungrounded insulating conductors and insulating dielectric materials (such as most ordinary plastics). In some environments, ionizing dissipators are used to partially dissipate electrostatic charges on these objects, and more often, air ionization is used to neutralize electrostatic charges on insulating media and isolated conductors. (3) electrostatic conductive electrical dissipative materials Electrostatic conductive materials electrical dissipative materials because of its electrostatic conductivity, is also a good static charge discharge material, and more safe than metal conductor discharge, usually used as floors, walls, worktables, turnover containers, tweezers, brushes and other anti-static equipment. 5, prevent ESD, protect the product This is the last step in the three steps to control static electricity. In the purification chamber of microelectronics production, in order to prevent ESD from occurring on electrostatic sensitive components or components, PCB, one method is to provide appropriate grounding or shunt to the components and components to "dissipate" the electrostatic charge present on the product; Another method is to use appropriate packaging methods and materials to deal with the packaging and transport of electrostatic sensitive devices. These materials can effectively shield the charge from entering the product and reduce the static charge generated by the product moving in the packaging box. Internationally, semiconductors, flat liquid crystal displays, optoelectronics are developing rapidly, the integration is getting higher and higher, the chip wire diameter is getting smaller and smaller, and the anti-static requirements are getting higher and higher. The American ESD Society has begun to revise the ANS ESD S 20.20-1999 electrostatic discharge control outline, and some changes have been made to the electrostatic sensitivity classification of SSDS. This gives the component user a warning, whether in the equipment manufacturing personnel or equipment, to tell you the environmental control requirements you can need. If the allowable voltage in the EPA area reaches 25V, I am afraid that our existing anti-static equipment, equipment, tools and engineering will have to go through a hard effort.