Charged Devide Model
Showing 14 of 14 articles in total.
Simulates static discharge from a static sensitive device to a conductor.
Please note - The term Class 0 has not been defined for manufacturing applications by any industry standard. Recent surveys have shown that manufacturing failure rates escalate exponentially for devices with ESD withstand voltages below 200 volts for either HBM (human body model) or CDM (charged device model). MM is intentionally omitted from this definition since it is largely redundant to HBM. It is also vitally important for the manufacturing process to have a well defined trigger for risk assessments of ultra-sensitive components. These risk assessments involve verification of manufacturing process capability as well as for any risks that may be passed on to customers. A working definition for a Class 0 devices is any component that fails below 200 volts for either HBM or CDM.
(1) A grounded device where two or more conductors are bonded. (2) A system or method for connecting two or more grounding conductors to the same electrical potential.
An instrument or collection of instruments that provide an indication or measurement. It may or may not be repeatable or accurate. This equipment is typically used for indications of pass or fail.
Computer grade carpet is the predecessor to conductive carpet. Computer grade carpet was designed during the infancy of the information age and contains a high density of bi-component yarns. Like all anti-static carpet, it cannot be grounded. The antistatic properties of computer grade carpet are usually described by obsolete standards, such as the IBM/Burroughs standard which grades the carpet by its kV rating (see low kV). A carpet specified for usage around computers should be rated by both kV rating and resistance to ground (measured in OHMS).
Refers to the ability of a material to conduct a charge to ground and is usually indicated by an electrical resistance range measured in ohms of a minimum of 2.5 x 104, (25,000 ohms), to a maximum of 1.0 x 106, (1 million ohms).
Fibers capable of conducting electricity to ground. Most conductive fibers contain carbon, graphite or stainless steel. Conductive carpets used by the computer industry are carbon-coated on the exterior of the fiber. External conductivity allows for static charges to make contact with the fiber’s conductive element and then safely discharge to a ground source, such as electrical conduit. Carbon fibers are inverted bi-component fibers. Conductivity is a permanent property.
The term conductive floor is often misconstrued as too conductive. Unlike highly conductive materials like copper and steel, conductive flooring is actually relatively resistive. Conductive floors like static dissipative floors are classified based upon their electrical resistance to ground. Electrical resistance is measured in ohms of resistance. The resistance to ground of a properly specified conductive floor is ≥ 2.5 X 104 and < 1.0 X 106 measured per ANSI/ESD STM7.1 Conductive flooring always meets all three recommended electrical parameters of ANSI/ESD S20.20. A type of flooring intended to prevent, mitigate, dissipate, conduct, remove or ground excessive static electricity charges on people, furniture, mobile carts and equipment. Static conductive flooring should not be confused with highly conductive materials including: copper, aluminum, silver, brass and gold. Unlike highly conductive materials, static conductive materials - by definition - possess an intrinsic electrical resistance of greater than 25,000 ohms per ANSI/ESD S7.1. 25,000 ohms resistance is the amount of resistance recognized in NFPA 99 standard for healthcare facilities. Static conductive flooring meets all the criteria for flooring in for use in an ESD control programs in ANSI/ESD S20.20. Static conductive flooring provides superior static control performance vs. static dissipative flooring. Independent testing has shown that rubber static conductive flooring will successfully inhibit static electricity on person wearing any kind of footwear.
A floor material that has a resistance to ground of less than 1.0 x 106 ohms.
A material that has a surface resistivity less than 1 x 105 ohms/square or a volume resistivity less than 1 x 104 ohm-cm.
A floor tile material used for the mitigation of electrostatic discharge (ESD) composed of carpet, synthetic rubber or vinyl composition. Meeting the same electrical parameters described as "conductive flooring." Conductive tiles are usually combined with conductive adhesive and grounded to either earth ground or electrical ground.
(1) The ratio of the current per unit area (current density) to the electric field in a material. Conductivity is expressed in units of siemens/meter. (2) In non-technical usage, the ability to conduct current.
A material with low electrical resistance, (a conductor), that will safely attract an electrical charge to ground. Examples of conductors are water, copper, aluminum and carbon. Practical examples of conductors are a lightning rod and a copper wire.
A resistance value incorporated in series with the wrist strap's electrical path to ground. This resistance limits electrical current that could pass through the ground cord in the event of inadvertent user contact with electrical potential.