An ESD glossary from Transforming Technologies
Decay time: The time interval in which a potential of a charged body is reduced from an initial value (maximum) to a defined lower value by connecting it to ground potential.Discharge time: The time interval in which a potential of a charged body is reduced from an initial value (maximum) to a defined lower value by means of forced recombination through ionizing equipment. Electrostatic discharge (ESD): Transfer of charge between bodies at different electrostatic potentials caused by direct contact or induced by electrostatic field. Electrostatic discharge sensitive devices (ESDS): Discrete devices, integrated circuits or assemblies that may be damaged by electrostatic fields or discharge encountered in routine handling, testing or transit. Electrostatic discharge shielding material: A barrier or enclosure that limits the passage of current and attenuates the energy resulting from an electrostatic discharge. ESD – susceptibility (voltage sensitivity): The maximum voltage at which the ESDS does not suffer any ESD damage. The ESDS are usually classified in different susceptibility classes. This is a controversial issue just to classify according to voltage level and not taking into account time, peak currents and transformed energy. A smaller voltage pulse lasting longer can cause more damage Electrostatic conductive material: Having a surface resistance ≥ 102 Ω and < 105 Ω (surface resistances, measured with the ESD S11.11 electrode, are a factor 10 lower than the resulting surface resistivities). ESD – protected area (EPA): An area in which ESDS can be handled with accepted reduced risk of damage as a result of electrostatic discharge or fields. EPA – Ground bonding point (EBP): A dedicated point to which an EPA-equipment and personnel via grounding cord can be connected. Electrostatic dissipative material: Having a surface resistance ≥ 105 Ω and < 1011 Ω (surface resistances, measured with the ESD S11.11 electrode, are a factor 10 lower than the resulting surface resistivities). Groundable point: A edicated point which can be connected to EPA- ground. Insulative material: A material with a surface resistance of ≥ 1011 Ω Low charging: Exhibiting properties which minimize any charge generation. The term “astatic” and “antistatic” should be avoided due to the different existing meanings and understandings. Proximity packaging: A transport material not making contact with ESDS but which is used to enclose one or more devices. Resistance to ground: Resistance between an electrode on the surface of an installed specimen and ground potential. Resistance to groundable point: Resistance between an electrode on the surface of a specimen and a counterlectrode, dedicated to be connected to ground potential under work conditions. Secondary packaging: Transport material used primarily to give additional physical protection to the outside of a proximity packaging. Surface resistivity: Equivalent to the surface resistance of a square area, having the electrodes at 2 opposite sides. Surface resistance: The ratio of a d.c. voltage applied between two electrodes on a surface of a specimen and the steady-state current between the electrodes. Triboelectric charging: Electrical charging process in which charge is generated by the contact and separation of two surfaces which may be solid, liquid or particulate-carrying cases. Volume resistance: The ratio of a d.c. voltage applied between 2 electrodes placed on 2 opposite surfaces of a specimen and the steady-state current between the electrodes. Volume resistivity: The ratio of a d.c. field strength (V/m) and the steady-state current density (A/m2) within the material. In practice, it is equivalent to the volume resistance of a cube with the unit length, having the electrodes at 2 opposite surfaces. Voltage suppression: The phenomenon of an apparent charge drainage by increasing the capacity of a charged body (e.g. getting close to a grounded electrode surface). Secondary packaging: Transport material used primarily to give additional physical protection to the outside of a proximity packaging.