Средства индивидуальной защиты Hoffmann Group 2026 - страница 369

GBP 57 INFORMATION ABOUT ESD PROTECTION Explanation of terms: ESD means Electrostatic Discharge. A spark or a breakdown is caused by a large difference in potential, and produces high electrical voltage pulses in electronic equipment. ESD = Electrostatic Discharge ESDS = Electrostatic Discharge Sensitive EPA = Electrostatic Protected Area Electrostatic discharge between charged objects Devices which can be damaged by A work area fitted with ESD protection measures through direct or close contact. electrostatic discharges when being used where electrostatic sensitive devices can be handled or transported. without being damaged. Electrostatic charges Pictograms: arise for instance due to: ■ Walking across plastic flooring ESD protective symbol Warning symbol for ESD sensitive ■ Friction against synthetic clothing (for items that possess at devices. ■ Moving plastic containers least one ESD control property). ■ Unrolling sticky tape ■ Moving conveyor belts For a human to perceive static discharge, it needs to have reached around 3,000 volts. In comparison, just 30 volts is enough to destroy a semiconductor device. Uncontrolled electrostatic discharges can lead to total failure as well as hidden defects in electronic assemblies (semiconductor devices), which can result in high costs. ESD clothing – product protection EN 61340 for ESD sensitive devices Where ESD sensitive product parts (such as in electronics production) may be Protection of electronic components damaged by electrostatic discharges from personnel, ESD clothing that will against electrostatic phenomena reliably dissipate electricity is required. In the past, personnel wore clothing Protective workwear certified to this standard is suitable for the manufacture predominantly of 100% cotton; this natural fibre has a very low ability to hold a of products that are sensitive even to low voltages of 100 Volt or more. Persons charge. This characteristic does however depend on the atmospheric humidity. In wearing ESD workwear protect such products in manufacture against electrical dry air the fibres lack moisture and lose their natural capacity to dissipate electrici- discharges that damage components. Clothing that is not suitable for an ty, so there is a risk that they build up a hazardous charge. For this reason, special ESD environment can generate static electrical charges due to friction, influences ESD clothing with integral carbon fibres is preferred. The carbon fibres minimise (magnetic fields, effects of fields) or separation of materials. the resistance and promote controlled dissipation of electric charges. Comprehensive protection in all areas Workstations and storage – Vol. 3 Hand tools and metrology – Vol. 2 Workplace/workstation Measuring An ESD protected work place should be ergonomically ad- It is essential to test protection devices regularly using aptable. Electrostatic charge is dissipated via the working measuring equipment. Measurements must always be area and a grounding cable, so the work place remains taken when entering an EPA and regular personnel checks charge-neutral. Chairs and standing stools should also must be performed. Work tables, floor mats and grounding have ESD protection. connections should be checked on a monthly basis and ESD monitoring instruments should be checked annually. The discharge resistance should have the following values: Storage containers ■ Work surfaces: between 7.5×105 Ω and 109 Ω ■ Floors: less than 109 Ω Dissipative ESD shelves and containers for transporting ■ Chairs/standing stools: less than 1010 Ω and storing devices protect at-risk devices. Roller cabinets should have conductive wheels. ■ Tools: less than 1012 Ω Floor The floor should be conductive and meet the required Tools limits of DIN EN 61340-5-1. When cleaning ESD floors, use only cleaning products that do not create layers, so that the To ensure safe handling of your devices conductivity values remain within the desired range. If only you should use ESD-compliant tools. individual workstations have been set up as EPA, ESD floor mats or tiles with grounding can also be fitted, but they must be clearly marked. Personal protective equipment – Vol. 4 Personnel grounding People are the main source of electrostatic charges. Shoes and wristbands with grounding cables are mandatory Markings for employees working in electronic production. ESD gloves and clothing are no substitute for personal Floor markings identify ESD protected areas. Signs and grounding using a wristband, but they should prevent a stickers are equally important in signalling potentially build-up of charge and prevent any sharp discharge. at-risk devices and assemblies. Wristbands can be found in Vol. 3 Workstations and Storage. 369