All the ESD Static Control Terms You Need to Know

Air ion

Groups of about 10 molecules (water, impurities, etc.), bound by polarisation forces into individually charged oxygen or nitrogen molecules.

 

Air Ionizer

Electrically charged source of air molecules (ions).

 

Antistat, agent

A substance applied partially or partially to a material so that the surface is dissipative to static electricity or less sensitive to frictional initiation.

 

Antistatic

Usually refers to the property of a material to inhibit the initiation of electricity by friction. Note: The antistatic characteristics of a material are unnecessarily linked to its impedance or resistance.

 

Auxiliary ground

Separate supplementary earthing conductor, unlike conventionally used earthing devices.

 

Charge decay

Reduction and/or neutralisation of the net residual electrostatic charge.

 

Charge induction

The transfer of charge when an insulated conductor is placed within an electric field (e.g. from a charged body). Note: The momentary grounding of the conductor at this point causes it to acquire a net residual charge.

 

Charged device model

A defined circuit that displays the characteristics of the electrostatic discharge generated when a device insulated from ground is first charged and then grounded.

 

Charged plate monitor(CPM)

A tool for measuring the charge neutralisation properties of ionisation equipment.

 

Cold workstation

A working area with products, components, black boxes or systems that do not use energy.

 

Common point ground

(1) An earthing device for connecting two or more conductors.
(2) A system or method for connecting two or more earthing conductors to the same potential.

 

Component

A finished product, such as resistors, two transistors, crystals, integrated circuits and hybrid circuits.

 

Component failure

A component under test does not comply with one or more of the specified static or dynamic parameter data.
Static parameters about the component are necessary in a non-functional state (spare parts). These parameters may include, but are not limited to: input leakage currents, input breakdown voltages, high and low output voltages, output drive currents, and supply currents.
Dynamic parameters regarding the components are necessary to achieve a functional state (operation). These parameters may include, but are not limited to: full functionality, rise and fall times of the output under specified loads, and the depiction of dynamic currents.

 

Conductive Material

The material has a surface resistivity of less than 1 x 105 ohm/square or a volume resistivity of less than 1 x 104 ohm-cm.

 

Conductivity

(1) The ratio of current per unit area of a material in an electric field (current density). The unit of electrical conductivity is expressed in “Siemens/m”.
(2) In non-technical terms, it is customarily referred to as the ability to conduct current.

 

Contact-mode Discharge

An ESD phenomenon is transferred to the internal part of the component. This transfer is generated by a probe connected to a component pin and this component is not in a socket.

 

Contact-mode, non-socketed discharge

An ESD phenomenon occurs by transferring to the inside of a component. This transfer is generated by a probe connected to a component pin and this component is not in a socket.

 

Decay rate

The amount of reduction in charge or voltage per unit of time.

 

Decay time

The time required to reduce the electrostatic potential to a set percentage of its initial value (usually 10%). (See Static Decay Test.)

 

Dissipative Materials

Materials with a surface resistance greater than or equal to 1 x 110⁴ ohms but less than 1 x10¹¹ ohms, or a volume resistance greater than or equal to 1 x 10⁴ ohms but less than 1 x10¹¹ ohms.

 

Discharge time

The time necessary to allow the voltage (due to electrostatic discharge) to decay from an initial value to an arbitrarily chosen final value.

 

Electric charge

Lack or excess of electrons.

 

ElectricField Shielding Materials

Materials with a surface resistance or volume resistance of less than 1 x 10³.

 

Electrical ionizer

A device for generating ions in a gas using high voltage electrodes.

 

Electrical Overstress(EOS)

The phenomenon of exposure when the current or voltage of an object exceeds its maximum rating. This phenomenon may or may not cause a serious fault.

 

Electrostatic discharge (ESD)

The rapid and spontaneous transfer of electrostatic charges due to a high electrostatic field. Note: Usually when two objects with different electrostatic levels are in close proximity to each other, charge flows through the sparks between them. Details of this process, such as the rate of charge transfer, are described in the specific electrostatic discharge model.

 

Electrostatic discharge ground

A point, electrode, bus, metal strip, or other conductor system that forms a path from a person or object carrying static electricity to ground.

 

Electrostatic discharge protected area (EPA)

Having a specific environment for limiting electrostatic potential materials and equipment.

 

Electrostatic discharge protective

Properties of a material with one or more of the following capabilities: reduction of electrostatic generation, elimination of electrostatic charges, shielding against electrostatic discharge or shielding against electrostatic fields.

 

Electrostatic discharge protective station

An area constructed and equipped with the necessary protective materials and equipment to limit damage to electro-statically discharged sensitive products within it.

 

Electrostatic discharge protective symbol

Graphic for identifying special designs where ESD protection products need to be provided.

 

Electrostatic discharge protective workstation

An area constructed and equipped with the necessary protective materials and equipment to limit damage to electro-statically discharged sensitive products within it.

 

Electrostatic discharge protective worksurface

A working surface where the electrostatic charge is removed by the material placed on the surface or by the surface itself.

 

Electrostatic discharge sensitivity(ESDS)

The ESD level that causes the component to fail. (Note: See Electrostatic discharge susceptibility.)

 

Electrostatic discharge susceptibility

The tendency to be damaged by electrostatic discharge. (See Electro-staticdischarge sensitivity.)

 

Electrostatic discharge susceptibility classification

The products are arranged according to a classification of electrostatic discharge sensitivity voltage values. Note: Various classification methods are available.

 

Electrostatic discharge susceptibility symbol

Graphics placed on hardware, components and documents in order to identify electrostatic discharge sensitive products.

 

Electrostatic discharge susceptible item

Electrical or electronic parts, devices, assemblies, components or equipment having an electrostatic discharge sensitivity level.

 

Electrostatic discharge withstand voltage

The maximum level of electrostatic discharge that does not cause component failure.

 

Electrostatic field

The amount of attraction or push-repulsion generated in space due to the presence of an electric charge.

 

Electrostatic potential

The voltage difference between a point and a reference.

 

Electrostatic shield

A barrier or encapsulant is used to limit the penetration of electrostatic fields.

 

Emitter

A sharp, electrically conductive object, usually a needle or wire, will cause a corona discharge when held at a high potential.

 

Equipment ground

(1) The grounding point of the equipment earth at any part of the end of the equipment conductor.
(2) The terminal of a 3-wire receptacle (green).
(3) The entire low impedance path from a part of the electrical equipment to a hard earth electrode.

 

ESD ground

A system of points, electrodes, buses, metal strips, or other conductors that form a pathway from a static charged body or object to ground.

 

ESD protective

A material property that has one or more of the following capabilities: prevents the generation of static electricity, dissipates static charges on its surface or volume, or provides shielding against ESD or electrostatic fields.

 

ESD protective station

An area that must be constructed and equipped with protective materials and equipment to limit damage to ESD sensitive products by touch within it.

 

ESD sensitivity

Electrostaticdischarge sensitivity and Electrostatic discharge susceptibility.

 

ESD withstand voltage

The highest voltage level that does not cause component failure.

 

ESDS

See ElectrostaticDischarge Susceptible and Electrostatic Discharge Sensitivity.

 

Faraday cage

An electrically conductive housing which attenuates a static electrostatic field.

 

Field induced charging

A charging method that uses electrostatic induction.

 

Flooring/Foot GrounderSystem Resistance

Total resistance when the foot grounder is worn by a person and the person is standing on the static control floor.

 

Foot Grounder System

A foot earthing device worn by the body with an electrical pathway that includes the body and the foot earthing device.

 

Foot Grounder System Resistance

Measurements of the total resistance of the foot earthed should be taken by a person wearing and standing on a stainless steel plate.

 

Ground

(1) A conducted connection between a circuit or device, whether intentional or accidental, and the earth or some conducting object in place of the earth.
(2) This location or part is of zero potential to the earth.
(3) A conducting object used as a return path for electric current like the earth, such as the shell of a steel ship, and an arbitrary zero reference point.

 

Ground cord

Part of the wrist strap with removable winding, completing the electrical connection between the wrist sleeve and the ground and ensuring flexibility of movement.

 

Ground fault circuit interrupter

A device for the protection of persons whose function is to delay the switching of a circuit or part of a circuit for a defined period of time. It is activated when the difference in current between the centre line and the fire line exceeds a number of predetermined values and this overcurrent, which protects the power circuit equipment. This difference in current is usually caused by the earth current.

 

Ground lead

A part of the wrist strap that provides flexibility of movement when a circuit is connected between the wrist sleeve and the earthing system.

 

Ground Pin

The plug or group of plugs that return current to the mains supply is called an earth plug.

 

Ground reference point

A grounding reference point is a fork on the equipment earth wire that can be hand soldered to a workstation grounding point. Examples include: (a) a grounding plug on an AC power cord; (b) a banana plug on a grounding wire; (c) a ring or spade lug on a grounding jumper.

 

Ground strap

(1) A conductor used to provide an electrical earthing path.
(2) A component used to provide an earth path with a specified resistance for personnel.

 

Groundable point

A specific connection location or combination used to provide a suitable electrical ground for ESD protective materials or equipment.

 

Groundable point ESD protective floor material

A point on the flooring material used to provide a suitable ground point for the electrical connection of the flooring material.

 

Groundable point, seating

Conductive castors or grounded drag chains to provide an electrical path between the seat cover and the static control floor or mat.

 

Grounded

Already connected to the ground or some other conducting object as ground.

 

Grounded conductor

A system or circuit conductor that has been deliberately earthed.

 

Grounding conductor

A conductor used to connect the earth circuit of a device or a wiring system to an earth electrode or group of earth electrodes.

 

Grounding resistance

The sum of the resistances from any point on a conducting path to the earth electrode.

 

Hard ground

Connected to ground by wire or other conductor with little or almost no resistance to ground (impedance).

 

Hot work station

A working area with an object, component, black box, or system, with power supply for testing or repair.

 

Human body model

An electrostatic discharge circuit with simulated data conforming to the waveform conditions of standard ESD-S5.1, showing the characteristics of a typical human discharge from a fingertip.

 

Impedance

The total resistance (i.e. resistance or reactance) offered by a circuit to the flow of AC current. It is measured in ohms, with lower ohmic values and better quality conductors.

 

Impedancen. Symbol z

The measurement of the total resistance to the flow of current in an AC circuit consists of two components, ohmic resistance and reactance, usually denoted by the symbol Z = R + iX, where R is the ohmic resistance and X is the reactance. Impedance is measured in ohms.

 

Inductive charging

The transfer of charge from an object when it is momentarily grounded within an electric field.

 

Insulative Materials

Materials with a surface resistance of at least 1 x 1012 ohm/square or a volume resistance of 1 x 1011 ohm-cm.

 

Ionization

The process of acquiring a positive or negative charge from a neutral atom or molecule.

 

Ionizer

Device for generating positive and/or negative air ions.

 

Isolated conductor

There is no grounded conductor.

 

Isolated ground receptacle

A type of earthing for containers where, due to the method of installation of the container, the container is in contact with the earthing conductor of the equipment, and the terminals are electrically insulated.

 

Machine model

The simulation test for electrostatic discharge is based on a discharge network consisting of a 200 microfarad charging capacitor, and a zero ohm series resistor (nominally). The actual series resistance and inductance series is determined by the current waveform of the test item through a short metal wire. This simulated test approximates the electrostatic discharge of a machine.

Main bonding jumper

Provides a connection between the earth circuit conductor and the equipment earth conductor.

 

Monitor, charge(d) plate

An instrument for measuring the charge neutralisation properties of ionic devices.

 

Neutralize

The elimination of an electrostatic field by recombining positive and negative charges, or by conducting either charge to ground, or by introducing an equal and opposite charge.

 

Non-contact mode, non-socketed discharge

An ESD phenomenon caused by the proximity of the probe tip to the device pin, which is not placed in the socket.

 

Nuclear ionizer

An ion-generating device that usually consists of alpha rays stripping electrons from gas molecules until an equal number of positive and negative ions are formed in the gas.

 

Offset voltage

The voltage observed from the insulated conductive plate of a charging plate monitor placed in an ionised environment.

 

Output protection

At the output of the object, components, devices or networks are connected to prevent damage from electrostatic discharge.

 

Oxide punch-through

Insulator breakdown of an oxide layer, e.g. in a semiconductor device.

 

Passive ionizer

A device, usually a sharply grounded spike, close to the discharge surface that forms a conduction pathway for air ions.

 

Peak offset voltage

For pulsed ion generators with a maximum residual voltage for each polarity, this value cycles between positive and negative ion outputs according to the ion generator’s period.

 

Periodic verification

Upon completion of the tests it was noted that the performance of the air ioniser remained unchanged from the initial data to beyond the selected limits.

 

Personnel grounding device

An electrostatic discharge protection device that discharges any electrostatic charge accumulated on the human body to earth.
Note: The impedance to earth of the personnel earthing device must be sufficiently high to avoid causing electrical accidents.

 

Planar material

An object with a surface large enough and flat enough to fit over the surface of an electrode to be used to measure the electrical properties of a material.

 

Point-to-point resistance

The ohmic resistance measured from two electrodes placed on any surface.

 

Garments

The ohmic resistance measured from one point to another on the surface of the same piece of cloth, or on two different pieces of cloth of a garment.

 

Resistance range

The user specified high and low end resistance values define the user acceptable resistance values for the wristband or wristband system.

 

Resistance to ground

The resulting ohmic resistance value measured between an electrode placed on the surface and ground.

 

Resistance to groundable point

The ohmic resistance value measured between an electrode and a ground point placed on a surface.

 

Room ionization

Ionisation system providing ionisation of large areas of air.

 

Service equipment

Required equipment, usually consisting of line breakers or switches and fuses and their accessories, located near the entrance to the power lines of a building or other structure, or of a separately defined area intended to form the main control and disconnection of power.

 

Sleeve-to-Sleeve Resistance

The ohmic resistance value obtained by measuring from the cuff of a garment to the other cuff of the same garment.

 

Socketed Device Model) (SDM

An approximate model of the discharge phenomenon, reproduced in the test system, includes the total charge storage of the ICs, sockets and RLC add-ons of the test simulator, which are discharged to an additional object of lower electrostatic potential (ground) via the relay matrix of the test system.

 

SocketedDevice Model (SDM) Tester

A device that simulates the component socket device model electrostatic discharge (SDM ESD) phenomenon level on a socket

 

Socketed Discharge

A removable isolated material is placed on the current floor and is dissipated by grounded personnel, equipment, or other grounded objects, or related materials that can control the generation and build-up of static charges.

 

Static control (or, electrostatic discharge control)

1. protective measures against electrostatic discharges.
2. General term for measures to reduce the effects of electrostatic discharges.

 

Static control floor

Permanently installed flooring materials, such as tile, carpet, polymer, epoxy, or sheet flooring, dissipate static charges by connecting people, equipment, or other objects on the floor, or control the generation and build-up of static charges associated with the flooring material.

 

Static control floor finish

A non-permanent coating applied periodically to common floor surfaces to dissipate static charges by connecting people, equipment, or other objects on the floor, or to control the generation and build-up of static charges associated with flooring materials.

 

Static control floor mat

A removable island of material is placed on the current floor and is connected to this floor by people, equipment, or other grounded objects to dissipate static charges or to control the generation and build-up of static charges associated with the floor material.

 

Static control floor material

Permanently installed flooring materials, such as tile, carpet, polymer, epoxy, or sheet flooring, dissipate static charges by connecting people, equipment, or other objects on the floor, or control the generation and build-up of static charges associated with the flooring material.

 

Static control footwear (footwear)

A covering for human feet which, when connected to a static control floor or ground, has the property of dissipating static charges, as defined in the standard.

 

Static control footwear (other devices)

Equipment (other than shoes) such as foot straps attached to the human foot, grounded toes, boots, or other electrical connectors that enable the control of static charge build-up when it is connected to a static control floor or ground coating, or floor mat.

 

Static control footwear (shoes)

A covering for human feet which, when attached to a static control floor or ground coating, or mat, has the property of controlling the build-up of static charges.

 

Static control garments

Personnel clothing designed for the control of electrostatic charges.

 

Static control seating

A seat cover designed for use with static control floors or static control mats for chairs that wish to control the generation, build-up and dissipation of static charges.

 

Static decay test

The process of measuring the duration of discharge of an item during which it is first charged to a specified voltage and then drained to a specified voltage.

 

Static dissipative

A property of a material having a surface resistivity of at least 1×10⁵ ohm/square or a volume resistivity of 1×10⁴ ohm-cm, but less than 1×10¹²ohm/square surface resistivity or 1×10¹ ohm-cm volume resistivity.

 

Surface resistance

The ratio of the flowing current to the DC voltage between two electrodes on the same side of the contacting material in the specified configuration. The unit of measurement is expressed in ohms.

 

Surface resistivity

Because current flows across the entire surface, this ratio is the ratio of the DC voltage drop per unit length to the surface current per unit width. In essence, the surface resistivity is the resistance between two opposite sides of a square and does not depend on the size of the square or its spatial units. Surface resistivity is expressed in ‘ohms/square’.

 

Triboelectric charging

When two materials come into contact or rub against each other and then separate, an electrostatic charge is generated. (See Triboelectric series)

 

Triboelectric series

A sequence of material arrangements. A material can carry a positive charge when separated from another material further down the sequence, or a negative charge when separated from another material further up the sequence. Note: The sequence is mainly used to indicate the polarity of the charge that may arise after friction. However, the sequence is derived from the special preparation and cleaning of the material and is tested under strictly controlled conditions. In a normal environment, materials properly placed close to another in the sequence are expected to produce charges of opposite polarity to each other. This sequence is only a guide.

 

Voltage suppression

According to the equation V = Q/C, it is better to reduce the voltage (V) of a charged object by increasing its capacitance (C) than by reducing its charge (Q). Note: Voltage suppression is typically reproduced when a charged object is close to ground.

 

Volume resistance of static dissipative materials

The ratio of a specified DC voltage to the current flowing between two electrodes, or in the lower part with a specified structure, touching opposite sides of a material or object. The volume resistance of a static dissipative material is expressed in ohms.

 

Volume resistivity

Ratio of DC voltage per unit thickness of material to the amount of current per unit area passed. The volumetric resistivity is set to ohm-cm.

 

Worksurfaces groundable point

A point on the working face prepared to provide an electrical connection between the working face and a suitable electrical ground.

 

Wrist strap

A combination apparatus comprising a wrist sleeve and an electrically connected grounding cord providing a human skin to ground.

 

Wrist strap system

When a wrist strap is properly worn by a person, its electrical path consists of the person, the wrist sleeve and the grounded flexible wire.