Electrostatic Discharge. ESD
Antistatic Material. A material having a surface resisitivity between 109 and 1014 ohms per square.
Antistatic Property. the reduction of triboelectrlc charge generation. Anti-static materials minimize the generation of static charges. This property is not dependent upon material resistivity.
Catastrophic Failure. A failure resulting in the permanent loss of a critical function.
Charged Device Model. [CDM] A model characterizing a particular ESD failure mechanism in which an item isolated from ground is charged and is subsequently discharged causing a short duration discharge pulse. One of three ESD models, refer to the chart below. The standard that defines CDM is; ESD STM5.3.1: Electrostatic Discharge Sensitivity Testing - Charged Device Model.
Classification of ESDS Parts.
ESD Class 1: Susceptible to damage from ESD voltages greater than O to 1,999 Volts.
ESD Class 2: Susceptible to damage from ESD voltages of 2,000 to 3,999 volts.
ESD Class 3: Susceptible to damage from ESD voltages of 4,000 to 15,999 volts.
ESD Class non-ESD Sensitive: Susceptible to damage from ESD voltages above 16,000 volts.
Note there are sub classifications, refer below right.
HBM; Human Body Model, HBM Definition
MM; Machine Model,
CDM; Charged Device Model
ESDS Models and Voltage Ranges
|Bipolar transistor (NPN)||E+ to B|
|Bipolar transistor (PNP)||E- to B+|
|Junction FET's (N-channel)||G+ to S|
|Junction FET's (P-channel)||G- to S+|
|MOSFET's (N- or P-channel)||G to S (both polarities)|
|Gate protected FET's (P-channel)||G to S (both polarities)|
|Rectifiers (hot carrier and schottky)||A- to K+|
|Thyristors||G to K (both polarities)|
|Unijunctions||G to B1 (both polarities)|
|Darlingtons||E to B (both polarities)|
|Small signal diodes||A to K (both polarities)|
Conductive Material. A material having a maximum surface resisitivity of 105 ohms per square.