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Topic: Dielectric breakdown

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	Empfasis - Ask The EMPF Helpline! - Dielectric Testing (Site not responding. Last check: 2007-11-05)
		The dielectric withstanding voltage test (also called high potential, over potential, voltage breakdown or dielectric strength test) applies a voltage higher than the test subject’s rated voltage for a specific duration between electrically isolated circuits and portions of a PCB, or between its isolated circuits, portions, and ground.
		Dielectric breakdown is a phenomena that typically must be avoided in circuit design to prevent failures leading to the replacement of the module and possibly further damage to adjacent circuits.
		Dielectric breakdown, in most laminates, typically results in localized oxidation and the destruction of the material’s electrical characteristics.
	www.empf.org /empfasis/july04/help704.htm (916 words)

	Electrical breakdown - Wikipedia, the free encyclopedia
		Electrical breakdown is often associated with the failure of solid or liquid insulating materials used inside high voltage transformers or capacitors in the electricity distribution grid.
		Electrical breakdown occurs within a gas (or mixture of gases, such as air) when the dielectric strength of the gas(es) is exceeded.
		As the dielectric constant of the material surrounding the conductor determines the maximum strength of the electric field the surrounding material can tolerate before becoming conductive, conductors that consist of sharp points, or balls with small radii, are more prone to causing dielectric breakdown.
	en.wikipedia.org /wiki/Electrical_breakdown (819 words)

	Dielectric Strength ASTM D 149 IEC 80243
		Dielectric Strength is a measure of the electrical strength of a material as an insulator.
		Dielectric strength is defined as the maximum voltage required to produce a dielectric breakdown through the material and is expressed as Volts per unit thickness.
		Dielectric strength is calculated by dividing the breakdown voltage by the thickness of the sample.
	www.ptli.com /testlopedia/tests/DielStr-d149.asp (384 words)

	Improving Safety and Performance with Dc Dielectric Testing
		The second is an abrupt dielectric breakdown due to electrical arcing or discharge, either through the insulation material, over the surface of the insulation material, or through the air.
		Because the electrical stress on the insulation is highest at the peak of the ac waveform, dielectric breakdown occurs at the peak of an ac test voltage.
		Because the breakdown occurs so quickly, and because it occurs at the peak voltage of the ac waveform, the ac and dc voltages appear exactly the same to the breakdown; that is, it appears as a peak voltage of very long duration.
	www.ce-mag.com /archive/02/Spring/gray.html (2485 words)

	Key measurements of ultrathin gate dielectric reliability and in-line monitoring
		In this paper a methodology for measuring thin gate dielectric reliability is discussed in which the focus is upon the elements of those test structures used in the evaluation, the design of the reliability stress matrix, and the generation of engineering design models.
		In this high-field regime, the thin gate dielectric current results from Fowler-Nordheim tunneling [9, 10], and the intrinsic-mode behavior for the gate dielectric breakdown is observed.
		The gate dielectric thickness indicated in Table 1 for the various cases was determined by measuring STI-bounded thin dielectric capacitors with the gate biased to accumulate the silicon surface (negative for p-substrate and positive for n-well).
	www.research.ibm.com /journal/rd/433/abadeer.html (4321 words)

	Electrocube - Support
		The dielectric in the capacitor is subjected to the full potential to which the device is charged and, due to small capacitor physical sizes, high electrical stresses are common.
		Dielectric breakdown may occur as a result of misapplication of high voltage transients (surges).
		This is due to the chemical activity of the dielectric material which causes a change in the physical or electrical properties of the capacitor.
	www.electrocube.com /support/bullet4.asp (1116 words)

	Nanotechnology at Zyvex
		Its counterpart, dielectric strength, indicates the relationship between thickness and breakdown voltage, and is expressed as a ratio of voltage to thickness.
		Dielectrics are susceptible to local heating effects that cause thermal and electrical breakdown, particularly in thin dielectrics.
		Breakdown of a 50 micron by 2 micron polysilicon-filled nitride isolation trench on a silicon-based MEMS device.
	www.zyvex.com /Products/MEBD_001a.htm (2273 words)

	Dielectric strength - Wikipedia, the free encyclopedia
		The theoretical dielectric strength of a material is an intrinsic property of the bulk material and is not dependent on the configuration of the material or the electrodes with which the field is applied.
		Breakdown occurs quite abruptly (typically in nanoseconds)., resulting in the formation of an electrically conductive path and a disruptive discharge through the material.
		The field strength at which breakdown occurs in a given case is dependent on the respective geometries of the dielectric (insulator) and the electrodes with which the electric field is applied, as well as the rate of increase at which the electric field is applied.
	en.wikipedia.org /wiki/Dielectric_strength (314 words)

	dielectric withstand test
		The exact determination of the breakdown voltage must therefore be attached to the measurement of an electrical value characteristic of the dielectric breakdown phenomenon.
		Through observation of the breakdown phenomena, via oscilloscopic methods, it is possible to assert that they are featured by very sharp variation in current in the test circuit; this latter consists of the dielectric strength test station and the sample tested (Diagram 2).
		The breakdown current in itself generally has the form of an extremely steep positive-going edge pulse, lasting about 1 micro-second or even less, and whose peak value is limited by the combined characteristics of the test station and the sample being tested.
	www.sefelec.com /en/dielectric-withstand-test.php (1095 words)

	t-clad insulated metal substrate thermal management materials/home
		The dielectric in Thermal Clad is prepared in separate layers to insure a void free coating.
		The ASTM definition of dielectric breakdown voltage is: the potential difference at which dielectric failure occurs under prescribed conditions in an electrical insulating material located between two electrodes.
		This is permanent breakdown and is not recoverable.
	www.bergquistcompany.com /ts_electronical.cfm (944 words)

	Testing
		Automated hipot testing makes it possible to produce fully trWith dielectric breakdown testing you are trying to answer the question "How much voltage can I apply between the wires before the insulation fails?" You increase the voltage until the current suddenly increases.
		In dielectric withstand testing you are trying to answer the question "Will this cable withstand a required voltage for a required time?" You apply the voltage for the amount of time and watch the current that flows.
		Dielectric breakdown testing may be required during the development of assemblies used in critical applications.
	www.rainselectric.com /html/testing.html (380 words)

	Ask Charley Archive
		Dielectric breakdown strength testing and liquid power factor testing are related in terms of the kinds of conditions that affect the test values, but they are not exact substitutes.
		In general, when trying to choose between the most appropriate dielectric breakdown voltage test - either ASTM D1816 or ASTM D877 - it is true that the D1816 is more sensitive to most of the contaminants that affect the dielectric capabilities of the oil.
		Frequently, to identify whether there is a real issue or problem indicated by the test results, it is necessary to cross reference dielectric breakdown voltage values with liquid power factor values and also to cross reference these with other oil quality test data.
	www.sdmyers.com /ask_charley/q17.html (791 words)

	Introduction to High Voltage Engineering
		Often times dielectric breakdown is followed immediately by the conduction of electrical current (from fractions of an ampere to millions of amperes depending on circumstances) through the newly formed conducting region.
		A popular solid dielectric is epoxy poured as a liquid (under vacuum conditions to remove gas bubbles) which is allowed to harden before high voltage is applied.
		Most of the region is filled with small E field and consequently catastrophic dielectric breakdown (spark) of the entire "gap" does not take place.
	www.eecs.wsu.edu /~pedrow/HV_Engineering/lecture/intro (1015 words)

	Dielectric Properties of Polymers - The Zeus Polymer Minute
		The dielectric constant is a measure of the influence of a particular dielectric on the capacitance of a condenser.
		The dielectric strength is the direct current voltage between two electrodes at which dielectric breakdown occurs and is an indicator of how good an insulator the material is. The voltage is increased until the material breaks down, there is an arc across the electrodes and substantial current flows.
		The dielectric properties of polymers are largely predictable from the chemical structure of the polymer.
	www.zeusinc.com /newsletter/dielectric.asp (2077 words)

	Capacitors
		Dielectric constants vary widely, and are a function of the frequency of the applied electric field.
		Considering a dielectric body in the form of a slender cylinder parallel to the electric field, the continuity of the tangential component of E means that E is the same inside and outside the body.
		The polarization of a dielectric is due to the polarization of its crystal lattice or molecules.
	www.du.edu /~jcalvert/phys/caps.htm (8217 words)

	Electrochemistry Encyclopedia --- Electrolytic capacitors
		It is directly proportional to the "dielectric constant" (Table I) and inversely proportional to the thickness of the dielectric.
		Normally, breakdown ratings for dielectrics are expressed as a maximum field strength which is basically the ratio of the applied voltage to the dielectric thickness.
		Also, the anodic oxide dielectric is polar, and so are the electrolytic capacitors (in contrast with the classical, electrostatic capacitors), that is the capacitors must be connected with the correct polarity as marked.
	electrochem.cwru.edu /ed/encycl/art-c04-electr-cap.htm (5009 words)

	What is dielectric material? - a definition from Whatis.com - see also: dielectric (Site not responding. Last check: 2007-11-05)
		A dielectric material is a substance that is a poor conductor of electricity, but an efficient supporter of electrostatic fields.
		Dielectric materials are also used in the construction of radio-frequency transmission lines.
		An important property of a dielectric is its ability to support an electrostatic field while dissipating minimal energy in the form of heat.
	whatis.techtarget.com /definition/0,,sid9_gci211945,00.html (400 words)

	Characterizing Size Distribution Of Core-Shell Spherical Particles Research Brief
		Research performed in collaboration with R. Anderson has determined the mechanism causing dielectric breakdown of epoxy composites containing 50 volume % of hollow glass spherical balloons.
		Dielectric breakdown of the composite is initiated by gas discharges inside the microballoons.
		The mechanism involves a "weakest-link" concept, in which a spontaneous discharge inside a single balloon within the composite launches a chain reaction of discharges which culminates in breakdown of the composite.
	www.sandia.gov /materials/sciences/factsheets/CharacSize.html (474 words)

	Impulse Breakdown Experiments (Site not responding. Last check: 2007-11-05)
		We are using the Febetron Pulser as a high energy source to produce pulses for dielectric breakdown experiments, which requires voltages in the megavolt region.
		The experiments are done on a pulse basis and the pulse length is chosen to be comparable to the time scale for the onset of breakdown, which is about 20 nano-seconds.
		Breakdown conduction occurs by way of this gaseous plasma in the complete channels, and it is not electronic conduction through the solid dielectric.
	hibp.ecse.rpi.edu /~leij/febetron/breakdown.html (344 words)

	High Voltage Breakdown Tester
		Dielectric breakdown is where a voltage increase causes an "insulator-to-conductor" transition in a material.
		The basic idea of a breakdown voltage tester is to apply current limited high voltage to an insulator, and raise the voltage until the desired voltage test level is reached, or until a small amount (1 to 2 micro Amps) of leakage current flows.
		Breakdown voltage is also a function of geometry.
	www.realhamradio.com /High_Voltage_Breakdown_Tester.htm (2790 words)

	tenue diélectrique [SEE QUESTION for important discussion!] - dielectric strength [NB: this usage is widespread but ... (Site not responding. Last check: 2007-11-05)
		Dielectric strength is defined as the maximum voltage required to...
		From the context it is clear that it refers to a breakdown voltage.
		"the quotient of the maximum voltage without breakdown and the distance between the conducting parts between which the voltage is applied under prescribed test conditions.
	www.proz.com /kudoz/1573076 (805 words)

	Electric Field to Produce Spark in Air (Dielectric Breakdown)
		Dielectric breakdown occurs when a charge buildup exceeds the electrical limit or dielectric strength of a material.
		Lightning occurs when there is a buildup of charge on the clouds and the ground It produces the electric field that exceeds the dielectric strength of air.
		The dielectric strength of air is approximately 3 kV/mm.
	hypertextbook.com /facts/2000/AliceHong.shtml (258 words)

	D149-97a(2004) Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical ...
		It may also be used to determine dielectric breakdown voltage along the interface between a solid specimen and a gaseous or liquid surrounding medium (flashover).
		It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
		breakdown; breakdown voltage; calibration; criteria of breakdown; dielectric breakdown voltage; dielectric failure; dielectric strength; electrodes; flashover; power frequency; process-control testing; proof testing; quality-control testing; rapid rise; research testing; sampling; slow rate-of-rise; step-by-step; surrounding medium; voltage withstand
	www.astm.org /DATABASE.CART/REDLINE_PAGES/D149.htm (492 words)

	3.5.1 Electrical Breakdown and Failure
		The critical parameter is the field strength E in the dielectric.
		In this case the breakdown may not be explosive; but a leakage current may develop which grows over time until a sudden increase leads to total failure of the dielectric.
		A typical result is that breakdown of a "good" dielectric occurs after - very roughly - 1 C of charge has been passed.
	www.tf.uni-kiel.de /matwis/amat/elmat_en/kap_3/backbone/r3_5_1.html (499 words)

	Dielectric Breakdown and the Corona Effect (Site not responding. Last check: 2007-11-05)
		This is the phenomenon know as ``dielectric breakdown''.
		Dielectric breakdown and the phenomenon of polarization will be very important to us in the next chapter.
		To conclude, may I suggest that you review the methods covered for evaluating the potential from the field (using Gauss's Law, to find the field) as this will be of the greatest use to us in our discussion of capacitance.
	www.phy.duke.edu /~rgb/Class/phy42/node16.html (817 words)

	Dielectric Breakdown in Continuous Models of Metal-Loaded Dielectrics -- from Mathematica Information Center
		Dielectric Breakdown in Continuous Models of Metal-Loaded Dielectrics
		We develop two- and three-dimensional models for breakdown of metal-loaded dielectrics based on the breakdown of random arrays of perfectly conducting cylinders and spheres embedded in a uniform breakdown-path geometry, and dielectric constant as a function of metal packing fraction.
		We compare the simulation results with exact lower bounds for the dielectric constant and scaling arguments for the breakdown field, which predict a linear relationship between the breakdown field and both the average surface-to-surface spacing between the metal particles and the minimum dielectric gap.
	library.wolfram.com /infocenter/Articles/2811 (149 words)

	Semiconductor OneSource: Semiconductor Glossary -- Search For : breakdown
		Time Dependent Dielectric Breakdown; common technique to evaluate reliability of gate oxides in MOS devices; either time needed to break an oxide stressed with high voltage is measured (CVS - Constant Voltage Stress), or time of current injection into the oxide after which oxide fails (CCS -Constant Current Stress).
		breakdown due to current increase caused by avalanche multiplication of charge carriers in the region featuring very high electric field.
		irreversible, catastrophic breakdown of an oxide in MOS structures.
	semiconductorglossary.com /default.asp?searchterm=breakdown (1141 words)

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