First, the basic principles of electrostatic protection […]
First, the basic principles of electrostatic protection
a. Inhibit the accumulation of static charge; b. Eliminate the generated static charge quickly, safely and effectively.
2. Anti-static work area
1. Floor materials a. It is forbidden to directly use wooden floors or lay wool, hemp, chemical fiber carpets and ordinary floor leather. b. The ground composed of electrostatic conductor materials should be selected, such as anti-static raised floor or laying anti-static mats on ordinary ground, and effectively grounded. c. It is allowed to use specially treated terrazzo floor, such as laying ground wire mesh, carburizing or spraying antistatic agent on the floor in advance.
2. Grounding a. The anti-static system must have an independent and reliable grounding device, the grounding resistance should generally be less than 10Ω, and the burying and detection methods should meet the requirements of GBJ 97. b. The anti-static ground wire shall not be connected to the neutral wire of the power supply and shall not be shared with the lightning protection ground wire. c. Use a three-phase five-wire system for power supply, and its earth wire can be used as an anti-static ground wire (but the neutral wire and the ground wire should not be mixed). d. The cross-sectional area of the grounding main line should not be less than 100mm2; the cross-sectional area of the branch trunk line should not be less than 6mm2; the grounding wire of the equipment and the workbench should be a multi-strand plastic-coated wire with a cross-sectional area of not less than 1.25mm2, and the color of the grounding wire should be yellow-green line appropriate. e. The connection method of the grounding main line should be brazing. f. The connection terminals of anti-static equipment should ensure reliable contact, easy to assemble and disassemble, and allow the use of various clip-type connectors, such as fish clips, plug sockets, etc.
3. Ceiling materials The ceiling materials should be made of antistatic materials. Generally, gypsum board products are allowed, and ordinary plastic products are prohibited.
4. Wall fabrics Antistatic wallpapers should be used for wall fabrics. Generally, gypsum paint or lime paint is allowed to be used for walls, and ordinary
Wallpaper and plastic wallpaper.
5. Humidity control a. The relative humidity of the anti-static work area should not be less than 50%. b. On the premise of not causing harmful effects to the product, it is allowed to use humidification equipment to spray formulations or water to increase the ambient humidity. c. The humidity of the computer room should comply with the relevant regulations in GB 2887, and similar computer rooms should also comply with this regulation.
6. Regional boundaries The anti-static work area should be marked with regional boundaries, and warning signs should be hung at obvious places. The warning signs should comply with the provisions of GJB1649. The entrance of the work area should be equipped with ionized air air bath equipment.
7. Charge source 4. Use and management of anti-static work clothes It is forbidden to use and contact the charge source that is easy to generate static charge in the anti-static work area.
Painted or impregnated surfaces, common plastic veneers, common vinyl and resin surfaces
Plastic and ordinary floor leather, polished and waxed wood floors. Plain vinyl overalls, caps, shoes
Ordinary polyester, synthetic fiber and nylon fabrics, plastic and ordinary rubber-soled shoes operating tools and equipment
Ordinary plastic boxes, racks, bottles, tray supplies and paper products, general foam and general moving tools, compressors, spray equipment, evaporation equipment, etc.
3. Anti-static facilities for electronic products
1. Electrostatic safety workbench a. The electrostatic safety workbench is the basic component of the anti-static work area. It consists of a workbench, an anti-static table mat, a wrist strap connector and a ground wire. b. There should be no less than two wrist strap connectors on the anti-static table mat, one for the operator and the other for the technician, inspector or other personnel. c. If necessary, the electrostatic safety workbench should be equipped with an ion wind static eliminator. d. It is not allowed to stack plastic boxes (sheets), rubber, cardboard, glass and other sundries that are prone to static electricity on the electrostatic safety workbench.
2. The anti-static wristbands should be worn by those who directly contact electrostatic sensitive devices. The wristbands should be in good contact with human skin. The wristbands must be non-irritating and allergic to the human body. The resistance value of the wristband system to the ground should be Should be in the range of 106 ~ 108Ω.
3. Anti-static containers During the development and production of electronic equipment, all containers for storage and turnover of SSDs (component bags, transfer boxes, printed board racks, component storage boxes, etc.) should have electrostatic protection properties. Metal and regular plastic containers are not allowed. If necessary, the turnover box for storing components should be grounded.
4. Ion wind static eliminator should use ion wind static eliminator to eliminate the static charge on the surface of insulating material.
5. Anti-static work clothes a. Persons entering the anti-static work area or contacting SSD should wear anti-static work clothes, and the fabric of anti-static work clothes should comply with the provisions of GB 12014. b. In an environment with a relative humidity greater than 50%, anti-static work clothes are allowed to use pure cotton products.
6. Anti-static work shoes Those who enter the anti-static work area or contact SSD should wear anti-static work shoes, and the anti-static work shoes should comply with the relevant provisions of GB 4385. Ordinary shoes are generally allowed, but conductive shoe harnesses or heel straps should be used at the same time.
7. When the anti-static transport vehicle transports the SSD or the whole and components containing the SSD, the transport vehicle with anti-static performance should be used.