ESD sensitive components can be protected by storing, handling and packing them only in an ESD protected environment.
Lightning is the most visible form of electrostatic discharge. Different potentials are suddenly discharged here. We all know how dangerous they can be, we are taught that in childhood. But we also know small discharges. If we walk across a carpet and then grab the door handle, the car door or shake hands with someone else, it can lead to a discharge. It crackles! These are more like the harmless discharges. In everyday professional life, however, discharges can also occur, which can have bad and grave consequences. All discharges are referred to as electrostatic endings, or ESD for short. It arises from the sudden charge equalization between objects with a different charge potential. These discharges can generate a large amount of electricity.
All objects have positive and negative elementary particles. Generally positive and negative charges neutralize each other. The objects are electrically neutral. If electrons are withdrawn from an object, an imbalance arises.
This imbalance is the charge potential. Charged objects strive for equilibrium due to discharge. In the event of such a sudden discharge, high currents flow in a small electronic component.
Now it is important that you protect yourself and your components.
ESD sensitive components can be protected by storing, handling and packing them only in an ESD protected environment. Precautions are taken here to avoid electrostatic charges. Potential differences are neutralized by slowly dissipating. This prevents the sudden discharge. Because it is the real danger. If the battery is discharged briefly and quickly, an enormously high discharge will be the result.
In addition to the symbols mentioned for ESD-vulnerable components, ESD-safe workspaces and ESD-safe objects, the abbreviation EPA (ESD protected area) should be added to ESD-safe protected rooms. It also makes sense to use an ESD test sticker with the date of the last inspection of the protective effect of the objects.
The effectiveness of the material is classified according to its resistance properties. The surface resistance plays a special role here: it is the electrical resistance of a conductive layer on the surface. Depending on the resistance properties, a distinction is made between:
• shielding materials
• electrically conductive materials
• electrically conductive materials
• insulating materials
In addition to the surface resistance, the following resistances are also important:
• Leak resistance (resistance to earth / protective conductor)
• Volume resistance / volume resistance (resistance, measured at opposite points of a material)
• Point to point resistance (resistance from electrode to electrode)
DIN-EN61340-5-1 / VDE0300 Protection of electronic components against electrostatic phenomena, general requirements
DIN-EN61340-5-2 / VDE0300 Protection of electronic components against electrostatic phenomena, user manual
DIN-EN61340-2-1 / VDE0300 measuring method - Ability to dissipate electrostatic charges
DIN-EN61340-4-1 / VDE0300 standard test method for special applications - electrical resistance of floor coverings and permanently installed floors
DIN-EN61340-4-3 / VDE0300 standard test method for special applications - footwear
DIN-EN61340-4-5 / VDE0300 standard test method for special applications - characterization of the protective effect of footwear and floor in connection with a person.
If ESD-sensitive components are processed, ESD-compliant personal and workplace equipment is necessary. In the case of people, the focus is on ESD-compliant clothing (shoes, coat, earthing bracelet), while workplace equipment should include a conductive floor covering as well as ESD-compatible workbenches and chairs. The most important measure is personal earthing.
Ground connections, mats and
Grounding bricks should be inspected weekly, bracelets daily.
Special cleaning agents must be used for cleaning, as conventional household can leave an insulating layer behind.
In order to be able to carry out work and measurements on electrostatically sensitive components safely and correctly, an ESD safe workplace is essential.
In the case of stationary construction, e.g. in ESD protection zones, so-called EPA (Electrostatic Protected Area), all elements that come into contact with people and components should be conductive. Floor mats, workstations, larger assemblies and personal grounding are carried out using so-called grounding modules or plugs, while clothing and tools always have to be aware of the ESD logo.
So-called mobile ESD workstations are necessary for assembled components or assemblies that cannot be processed, repaired or serviced in the EPA area.
The classic mobile workstation (also known as a handling set) consists of a workstation support, a wristband for personal earthing and an earthing cable with an earthing plug. If there is no socket available, the earth wire can also be attached to earthed metallic surfaces with the aid of an alligator clip. The static discharge takes place over the mat if it is correctly set up. With this method, it must be ensured that the resistance “hand to earth” is less than 3.5 x 107 ohms.
The ESD sensitivity of electronic components increases with the increasing miniaturization of the components. Furthermore, ever smaller components offer less and less space for protective circuits on the microchips. In order to save energy, components have to get by with less power. To cause damage to a blue LED, for example, discharges of just 50 volts are sufficient. SMDs are at risk from voltages of 100 V. In contrast, the human perception potential is very limited. Discharges can only be felt from voltages of 3500 volts, audible from 4500 volts and visible from 10,000 volts.
ESD-damaged assemblies are usually invisible to the naked eye. Even tiny discharges can lead to total failure. These direct errors can usually be identified during quality control. The so-called latent errors are particularly critical. They only come to light when the products are in use. The effort to fix these intrinsic errors is the most expensive. As a rule, ESD damage is latent damage. Appropriate precaution is therefore imperative.
If you have any further questions, do not hesitate to call us, we are glad to help you.
You can find our complete product portfolio on the subject of ESD-compliant tools for use in ESD protection areas in our catalog. Often, however, work must also be carried out outside of these protection areas in which ESD sensitive parts have to be installed. Here, too, we offer complete solutions that can be used on the move, such as table supports, earthing plugs for sockets, hand tools and clamping devices.
