US3768058A - Metal oxide varistor with laterally spaced electrodes - Google Patents

Metal oxide varistor with laterally spaced electrodes Download PDF

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US3768058A
US3768058A US00165001A US3768058DA US3768058A US 3768058 A US3768058 A US 3768058A US 00165001 A US00165001 A US 00165001A US 3768058D A US3768058D A US 3768058DA US 3768058 A US3768058 A US 3768058A
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major surface
varistor
electrodes
electrode
alpha
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J Harnden
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General Electric Co
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General Electric Co
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
    • H01C7/10—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material voltage responsive, i.e. varistors
    • H01C7/102—Varistor boundary, e.g. surface layers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/49082—Resistor making
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/49082—Resistor making
    • Y10T29/49087—Resistor making with envelope or housing

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  • METAL OXIDE VARISTOR WITH LATERALLY SPACED ELECTRODES My invention is directed to a circuit component including a metal oxide varistor having laterally spaced electrodes.
  • V is the voltage between two points separated by a body of the substance under consideration
  • I is the current flowing between the two points
  • C is a constant
  • alpha is an exponent greater than 1.
  • silicon carbide varistor's typically'silicon carbide varistors exhibit an alpha of no more than 6.
  • varistors having alphas in excess of 10 within the current density range of 10 to 10 amperes per square centimeter may be made from bodies which are comprised of metal oxides.
  • the metal oxide body may be formed predominantly of zinc oxide with small quantities of one or more other metal oxides being present.
  • Metal oxide varistors having alphas in excess of 10 are disclosed in Canadian Pat. No. 831,691, issued Jan. 6, 1970, for example. While the alphas of these metal oxide varistors are identified by the current density range of 10" to 10 amperes per square centimeter, which characteristically exhibits substantially constant alphas, it is appreciated that their alphas remain high also at higher and lower currents, although some decline from maximum alpha values have been observed.
  • the construction of a conventional metal oxide varistor having an alpha in excess of 10 is shown in FIG. 1.
  • the metal oxide varistor 1 is formed of a sintered ceramic metal oxide body 3.
  • the body includes a first major surface 5 and a second, opposed major surface 7.
  • the major surfaces are separated by a thickness X.
  • First and second electrodes 9 and 11 are associated with the first and second major surfaces respectively, so that they lie in ohmic contact therewith.
  • my invention is directed to the combination comprised of a substrate having first and second opposed major surfaces comprised of a sintered ceramic metal oxide varistor body lying along at least the first major surface and having an alpha in excess of 10 in the current density range of 10" to l0 amperes per square centimeter.
  • First and second electrodes lie in ohmic contact with the first major surface and are laterally spaced to form a conduction gap therebetween along the first major surface having a minimum width less than the thickness of the substrate between the major surfaces.
  • FIG. 1 is a schematic sectional view of the conven tional metal oxide varistor discussed above;
  • FIG. 2, 3, and 4 are schematic sectional views of separate embodiments according to my invention.
  • FIG. 5 is a schematic circuit diagram
  • FIGS. 6 and 7 are schematic sectional views of additional embodiments according to my invention.
  • FIG. 8 is a schematic circuit diagram utilizing the embodiment of FIG. 7;
  • FIG. 9 through 12 inclusive are plan views of additional embodiments according to my invention.
  • FIG. 13 is a schematic sectional view of a packaged unit incorporating the varistor of FIG. 3.
  • a varistor 20 is shown formed according to my invention.
  • the varistor includes a metal oxide varistor body 21 having an alpha as defined by equation 1 in excess of 10.
  • the metal oxide varistor body may be formed according to the teaching of the Canadian patent cited above or in any other known manner.
  • the body is provided with a first major surface 22 and a second, opposed major surface 23.
  • the second major surface is shown to be parallel to the first major surface, but may take any geometrical form convenient for the specific application to which the varistor is to be placed.
  • the thickness of the varistor body measured normal to the major surfaces is not critical and may vary widely. The varistor body thickness is in most instances chosen so that the varistor body is rugged enough to avoid damage both in fabrication and handling.
  • the varistor body will normally exhibit a thickness of at least 25 microns.
  • the maximum thickness of the varistor body there is no limit to the maximum thickness of the varistor body, except that excessive thicknesses may unnecessarily add to the bulk and cost of the varistor as well as lengthening the thermal impedance path through the varistor body.
  • first electrode 24 and a second electrode 25 Mounted on the first major surface is a first electrode 24 and a second electrode 25.
  • the electrodes may be ohmically conductively associated with the major surface in any convenient conventional manner.
  • the electrodes are laterally separated by a width Y, referred to as the conduction gap width.
  • the conduction gap width determines the voltage level to be observed across the electrodes for a given current conduction level. Accordingly, it is desirable in most instances to precisely control this width. This can be accomplished by positioning the electrodes using known masking techniques to assure that they are accurately spaced or by initially forming a single electrode and thereafter relieving an intermediate portion of the electrode in a controlled manner to leave the first and second electrodes in spaced relation.
  • the conduction gap width Y may be of any desired value, depending upon the voltage desired for a given level of current conduction.
  • the lateral spacing of the electrodes of the varistor 20 is, however, particularly advantageous'when the conduction gap width Y is less than the thickness of the varistor body, as would be the case in comparatively low voltage applications. To illustrate this, it is merely necessary to observe that if an electrode spacing'of 2 microns between electrodes is indicated to yield the desired current and voltage characteristic for a varistor, it would be necessary to form the varistor body 3 with the thickness -X being a value of only 2 microns.
  • the varistor body 21 can be formed of any convenient thickness. It is only the conduction gap width Y that must be controlled at 2 microns. By comparison to forming the varistor body itself .of this small thickness, like spacing of the electrodes is quite simple to accomplish employing techniques well known to the art.
  • the operation of the varistor 20 differs from that of a conventional varistor as shown in FIG. 1.
  • a potential is impressed across electrodes 24 and 25, the current that is conducted between the electrodes is along or immediately beneath the surface of the varistor body within the conduction gap Y.
  • the conventional varistor in which the current is more or less uniformly distributed within the bulk of the varistor body.
  • the varistor 20 there will be some fraction of the current that will be carried through the bulk of the varistor body beneath the surface of the body, particularly as higher voltages are reached, but this should still be only a small proportion of the total current and may under most circumstances be considered negligible.
  • the varistor 2 will follow equation 1 similarly as varistor 1, its internal conduction mode is quite dissimilar.
  • FIG. 3 a varistor 30 is shown, which is a modified form of my invention.
  • a sintered ceramic metal oxide varistor body 31 is provided having a first major surface 32 and a second major surface 33. Electrodes 34 and 35, identical to electrodes 24 and 25, are associated with the first major surface and are separated by conduction gap width Y.
  • a dielectric support 36 is associated with the second major surface.
  • the dielectric support may be chosen from any one of a variety of electrically insulative, comparatively inert materials, such as, but not limited to, known glass, ceramic, and polymeric insulators.
  • the advantage of using the support 36 is that the thickness X3 of the varistor body can new conveniently be reduced, since the ruggedness of the varistor body itself is supplemented to a considerable extent by the'support.
  • the combined thickness of the varistor body and support, which together form a common substrate can be greater than the conduction gap Y, although this is not absolutely essential to all applications of my invention. It is recognized that in some circumstances, particularly when the support is a ceramic, it may be advantageous to form the varistor body as a coating on the upper surface of the support.
  • the varistor body and dielectric support can be bonded together to form a unitary substrate by conventional bonding techniques.
  • a varistor 40 is shown provided with a varistor body 41, which may be identical to 21, having a first major surface 42 and a second, opposed major surface 43.
  • a first electrode 44 is ohmically conductively associated with a portion of the first major surface.
  • a second electrode 45 is provided with a portion 45A ohmically conductively associated with the first major surface and laterally spaced from the first electrode by conduction gap width Y.
  • a remaining portion 45B of the second electrode is associated with the second major surface, and an intermediate portion 45C ohmically conductively connects the portions 45A and 45B of the second electrode.
  • the first electrode and the portion 45B of the second electrode are separated by a thickness X2, which exceeds the conduction gap width Y.
  • the varistor 40 When the varistor 40 is called upon to conduct low current levels, its operation is identical to that of varistor 20. That is, current is conducted almost exclusively across conduction gap Y, and a relative stable low level voltage range (compared to that obtainable using a resistor) is maintained across the electrodes. Should, however, the voltage level continue to rise across the first and second electrodes, as might occur in the case of a high power surge requiring current conduction beyond the capacity of the conduction gap at the first major surface, the voltage across the electrodes can be stabilized again at a somewhat higher voltage level determined by the spacing X2 between the first electrode and the portion 45B of the second electrode.
  • the conduction gap width Y though lower in value than the thickness X2, relies for current conduction upon a relatively restricted area of the varistor body lying adjacent or immediately below the surface of the conduction gap, and for this reason its current conducting capabilities are limited.
  • the somewhat more widely spaced first electrode and portion 458 of the second electrode are capable of conducting current therebetween through the bulk of the varistor body over a relatively extended area.
  • the varistor 40 combines the very low voltage characteristics of the varistor while also incorporating as an added feature the larger power handling capability of a conventional varistor, such as shown in FIG. 1, which also offers a second range of voltage stabilization.
  • Each of the varistors 20, 30, and 40 can be placed in an electrical circuit to provide a shunt path around a high voltage degradable circuit unit, as :is illustrated in FIG. 5.
  • the varistor is connected in the circuit to selectively shunt current around the degradable unit in proportion to the voltage across the terminals 50 and 51.
  • the current through the varistor rises exponentially with any increase in voltage and hence serves to stabilize the voltage across the terminals.
  • the varistor includes a varistor body 61 having a first major surface 62 and a second major surface 63 opposed thereto. Associated with the first major surface are first, second, and third electrodes 64, 65, and 66, respectively. The electrodes are each laterally spaced with the second electrode being interposed between the first and third electrodes. The first and second electrodes are separated by a conduction gap width Y1 and the second and third electrodes are separated by a conduction gap width Y2, which exceeds conduction gap width Y1 in value.
  • the varistor 60 possesses all the advantages of the varistor 20 plus the added advantage that the first and third electrodes can be simultaneously and independently referenced to the second electrode.
  • the resistance to current flow between the first and second electrodes can be related to the resistance to current flow between the second and third electrodes to provide any desired ratio of these resistances.
  • the gap Width Y1 and Y2 may be equal in value.
  • a varistor 70 is illustrated which is provided with a varistor body 71 that may be identical to varistor body 41. Adjacent first major surface 72 first and second electrodes 74 and 75 are located separated by conduction gap width Y. A third electrode 76 is associated with the second major surface 73. The third electrode is separated from the first and second electrodes by a thickness X2 of the varistor body. The thickness X2 exceeds the gap width Y. Both the first and second electrodes can be referenced to the third electrode while at the same time being referenced at a lower voltage range with respect to each other.
  • FIG. 8 A specific application for the varistor 70 is shown in FIG. 8.
  • Circuit terminals 80 and 81 are shown. These terminals may be connected to a series related electrical load and power source.
  • the anode terminal 82 and the cathode terminal 83 of an SCR 84 are shown connected to the terminals 80 and 81, respectively.
  • Gate terminal 85 of the SCR is connected to the cathode of a diode 86 and the anode of the diode is connected to other conventional trigger circuitry 87 which is in turn electrically connected to the terminals 80 and 82.
  • the first electrode 74 of the varistor is connected to the gate terminal 85.
  • the second electrode 75 of the varistor is connected to the SCR anode terminal 82, and the third electrode 76 of the varistor is connected to the cathode terminal 83 of the SCR.
  • the varistor acts as a shunt across the SCR 84. Should a voltage surge develop across the SCR it would be shunted through the varistor body between the second and third electrodes and 76. At the same time the varistor 70 is also capable of shunting a lower voltage that might develop across the diode 86 and coventional trigger circuitry 87. This could occur, for example, if a reverse voltage were applied to the SCR well within its voltage blocking capability, but approaching the voltage blocking capability of the diode 86. In this instance the diode is protected by the varistors voltage clamping ability through conduction gap width Y between the first and second electrodes.
  • the portion of the varistor having the highest power handling capability is used to protect the power handling portion of the circuit, namely the SCR, while the portion of the varistor having a lower power handling capability, the first major surface associated conduction gap, protects the signal portion of the circuit.
  • excessive gate voltages are prevented by the varistor, since in this instance conduction can occur through the varistor body between electrodes 74 and 76.
  • the varistor 60 could be substituted for the varistor 70 in the circuit shown iwth first electrode 62 being connected to gate terminal 85, second electrode 65 connected to anode terminal 82, and third electrode 66 connected to cathode terminal 83.
  • FIG. 9 A simple approach for increasing the distance traversed by the conduction gap on a major surface of a varistor according to my invention is best appreciated by reference to FIG. 9.
  • a varistor 90 having a circular first eleectrode 91 and an annular second electrode 92 which is concentric with the circular electrode and whichis uniformly spaced from the circular electrode by a conduction gap width Y. It may be readily observed that the distance traversed by the conduction gap exceeds the outer diameter of the annular electrode 92. In this way the current carrying area is increased over what would be present if two semicircular electrodes were employed in association with the same underlying varistor body.
  • a varistor is provided with a central first electrode 101 having a plurality of regularly spaced fingers 102 extending radially outwardly.
  • An outer electrode 103 is provided with a plurality of radially inwardly spaced fingers 105 interdigitated with the fingers 103.
  • a variable spacing between the inner and outer electrodes is required if an equal amount of current is to be conducted throughout the conduction gap, as the different curvatures presented by the different portions of the fingers will produce differing electrical fields if a uniform spacing is employed. Where unequal stresses can be tolerated on the fingers, it may be most convenient to provide a uniform spacing between the fingers or an approximately uniform spacing.
  • a varistor 110 is illustrated which is provided with a first electrode 111 and a second electrode 112 associated in laterally spaced relation to an underlying varistor body.
  • the electrodes are formed so that they are laterally separated by a minimum conduction gap width Y3 and progressively diverge to a maximum conduction gap width Y4.
  • the effect of varying the conduction gap width in this manner is to cause the varistor to present a somewhat lower alpha than should be present based upon the characteristics of the varistor body, per se.
  • This approach is particularly useful in using metal oxide varistors incorporating varistor bodies having an alpha in excess of 10 in the current den sity range of from 10 to 10 amperes per square centimeter to replace previously utilized varistors, such as selenium and silicon carbide varistors having alphas appreciably below 10.
  • a varistor 120 is illustrated having a first electrode 121 and a second electrode 122.
  • the two electrodes are laterally spaced on a varistor body in two discrete stepped increments.
  • the left hand portion of each electrode is laterally spaced by a conduction gap width Y5 which is less than the conduction gap width Y6 of the right hand portion of each electrode.
  • the voltage across the gap width Y5 may approach the voltage level in which the right hand portion of the device becomes active. In this way an aging device is protected against runaway voltages developing for a period of time permitting replacement before uncontrolled voltage increase occurs.
  • the varistors formed according to my teachings are free of any protective packaging or external lead connections.
  • the varistors may be utilized in protected environments without additional packaging.
  • the varistors could be incorporated in a hermetically sealed housing alone or in combination with other electrical components.
  • terminal leads to the electrodes and to encapsulate the varistors in a dielectric material to assure protection from environmentally encountered substances altering their electrical characteristics.
  • the varistor 30 shown in FIG. 3 is illustrated as the packaged varistor 130 shown in FIG. 13. Elements of the varistor 130 corresponding to those of the varistor 30 are assigned like reference characters and are not redescribed. Terminal leads 134 and 135 are soldered or otherwise suitably attached in low impedance relation to the electrodes 34 and 35, respectively.
  • a substantially impervious dielectric body 136 preferably formed of a dielectric glass of a type conventionally employed in the passivation and/or packaging of semiconductor crystals, is shown overlying the conduction gap and the adjacent edges of the electrodes.
  • the packaging dielectric 137 may be used alone with the dielectric body 136 being omitted. As shown, the dielectric package cooperates with the dielectric substrate 36 to completely cover the exterior surfaces of the varistor body. Where the varistor is of a form lacking a dielectric substrate, it is appreciated that the package dielectric 137 may also completely envelop the varistor body and, optionally, its attached electrodes.
  • varistor bodies While I have described my invention with reference to certain preferred embodiments, it is appreciated that numerous variations in form will readily occur to those skilled in the art. For example, while I have disclosed the varistor bodies to be of limited and regular lateral extent, it is appreciated that the lateral extent of the varistor body beyond the conduction gap width is not critical to its current conduction capabilities. For this reason I contemplate that varistors according to my invention may be formed with the varistor body extending laterally well beyond (or short of) the electrode outer edges, if desired, and utilizing lateral outline geometries of any convenient regular or irregular configuration.
  • the varistor body is itself a fairly good thermal conductor and will dissipate heat readily from the area immediately underlying the conduction gap. While a specific form of electrode interdigitation has been shown for purposes of illustration, it is appreciated that electrode interdigitation is per se well known in the electronic components arts and that many alternate forms of electrode interdigitation could be easily substituted.
  • the combination comprising a substrate having first and second opposed major surfaces comprised of a metal oxide varistor body lying along at least said first major surface and having an alpha in excess of in the current density range of from 10" to 10 amperes per square centimeter and first and second electrodes lying in ohmic contact with said first major surface and laterally spaced to form a conduction gap therebetween along said first major surface having a minimum width less than the thickness of said substrate between said major surfaces.
  • said substrate consisting of a metal oxide varistor body
  • said varistor body having an electrical resistance which varies as a function of applied voltage in accordance with the formula I )alpha where V is the voltage in volts applied to the body, I is the current in amperes through the body resulting from such voltage, and C and alpha are constants;
  • said body having an alpha in excess of 10 in the current density range of from 10 to 10 amperes per square centimeter;
  • first and second electrodes lying in ohmic contact with said first major surface and laterally spaced on said first major surface to form a conduction gap therebetween along said first major surface;
  • said conduction gap having a minimum width less than the thickness of said varistor body measured normal to said first major surface.
  • a third electrode lies in ohmic contact with said first major surface, said third electrode lying in laterally spaced relation with said second electrode and laterally separated from said first electrode by said second electrode, said second and third electrodes forming a conduction gap therebetween along said first major surface having a minimum width along said first major surface exceeding the maximum width along said first major surface of the conduction gap between said first and second electrodes.
  • first and second electrodes lying in ohmic contact with said body along said major surface and laterally spaced relatively to form a conduction gap therebetween, and
  • dielectric means overlying said varistor body along the conduction gap and cooperating with adjacent edges of said electrodes to protect said varistor body against alteration of its electrical characteristics.
  • a varistor comprising a metal oxide varistor body having an electrical resistance which varies as a function of applied voltage in accordance with the formula I V/ )alpha where V is the voltage in volts applied to the body, I is the current through the body in amperes resulting from such voltage, and C and alpha are constants;
  • said body having an alpha in excess of 10 in the current density range of from 10' to 10 amperes per square centimeter; said body having at least one major surface; first and second electrodes lying in ohmic contact with said major surface and laterally spaced on said major surface to form a conduction gap therebetween along said major surface; said conduction gap having a minimum width less than the thickness of said body measured normal to said major surface.
  • the combination comprising a metal oxide varistor body having an alpha in excess of 10 in the current density range of from 10 to 10 amperes per square centimeter and presenting first and second opposed major surfaces, first and second electrodes lying in ohmic contact with said first major surface and laterally spaced to form a conduction gap therebetween along said first major surface having a minimum width less than the thickness of said body between said major surfaces, and a third electrode lying in ohmic contact with said second major surface.
  • said varistor body comprises predominantly zinc oxide.

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US00165001A 1971-07-22 1971-07-22 Metal oxide varistor with laterally spaced electrodes Expired - Lifetime US3768058A (en)

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US (1) US3768058A (enrdf_load_stackoverflow)
JP (1) JPS5434902B1 (enrdf_load_stackoverflow)
DE (1) DE2235783C2 (enrdf_load_stackoverflow)
FR (1) FR2146453B1 (enrdf_load_stackoverflow)
GB (1) GB1366008A (enrdf_load_stackoverflow)
IE (1) IE36427B1 (enrdf_load_stackoverflow)
SE (1) SE383794B (enrdf_load_stackoverflow)

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US3818411A (en) * 1971-10-13 1974-06-18 Gen Electric Metal oxide varistor with selectively positionable intermediate electrode
US3857174A (en) * 1973-09-27 1974-12-31 Gen Electric Method of making varistor with passivating coating
US4064475A (en) * 1976-07-12 1977-12-20 Allen-Bradley Company Thick film varistor and method of making the same
US4069465A (en) * 1976-07-12 1978-01-17 Allen-Bradley Company Cylindrical varistor and method of making the same
US4371860A (en) * 1979-06-18 1983-02-01 General Electric Company Solderable varistor
US4506285A (en) * 1982-08-20 1985-03-19 Siemens Aktiengesellschaft Substrate made of varistor material having a plurality of electronic components mounted thereon
EP0184645A3 (en) * 1984-12-14 1987-01-28 C. Conradty Nurnberg Gmbh & Co. Kg Chip varistor and production process
US4720760A (en) * 1984-07-24 1988-01-19 Bowthorpe Emp Limited Electrical surge protection
US5438473A (en) * 1993-09-30 1995-08-01 Allina; Edward F. Varistor connection and usage
US5699035A (en) * 1991-12-13 1997-12-16 Symetrix Corporation ZnO thin-film varistors and method of making the same
US20070217110A1 (en) * 2005-11-22 2007-09-20 Yung-Hao Lu Tri-phase surge protector and its manufacturing method
US20070223170A1 (en) * 2006-03-27 2007-09-27 Tdk Corporation Varistor and light-emitting apparatus
US20090243768A1 (en) * 2008-03-28 2009-10-01 Tdk Corporation Varistor
US9356089B1 (en) 2015-02-26 2016-05-31 International Business Machines Corporation Low temperature fabrication of lateral thin film varistor

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DE3140802A1 (de) * 1981-10-14 1983-05-26 AEG-Telefunken Nachrichtentechnik GmbH, 7150 Backnang Mehrelektrodenvaristor
US4785276A (en) * 1986-09-26 1988-11-15 General Electric Company Voltage multiplier varistor
CN109950013B (zh) * 2017-12-20 2021-02-09 成都铁达电子股份有限公司 一种陶瓷芯片及压敏电阻器
CN110400666B (zh) * 2018-04-24 2021-07-20 成都铁达电子股份有限公司 组合式压敏电阻器
CN110400667B (zh) * 2018-04-24 2021-07-13 成都铁达电子股份有限公司 一种低固有电容压敏电阻器
CN110400665B (zh) * 2018-04-24 2021-09-28 成都铁达电子股份有限公司 一种芯片式低固有电容压敏电阻器

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US3271591A (en) * 1963-09-20 1966-09-06 Energy Conversion Devices Inc Symmetrical current controlling device

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3818411A (en) * 1971-10-13 1974-06-18 Gen Electric Metal oxide varistor with selectively positionable intermediate electrode
US3857174A (en) * 1973-09-27 1974-12-31 Gen Electric Method of making varistor with passivating coating
US4064475A (en) * 1976-07-12 1977-12-20 Allen-Bradley Company Thick film varistor and method of making the same
US4069465A (en) * 1976-07-12 1978-01-17 Allen-Bradley Company Cylindrical varistor and method of making the same
US4371860A (en) * 1979-06-18 1983-02-01 General Electric Company Solderable varistor
US4506285A (en) * 1982-08-20 1985-03-19 Siemens Aktiengesellschaft Substrate made of varistor material having a plurality of electronic components mounted thereon
US4720760A (en) * 1984-07-24 1988-01-19 Bowthorpe Emp Limited Electrical surge protection
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US9536732B2 (en) 2015-02-26 2017-01-03 International Business Machines Corporation Low temperature fabrication of lateral thin film varistor
US9865674B2 (en) 2015-02-26 2018-01-09 International Business Machines Corporation Low temperature fabrication of lateral thin film varistor
US9870851B2 (en) 2015-02-26 2018-01-16 International Business Machines Corporation Low temperature fabrication of lateral thin film varistor
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Also Published As

Publication number Publication date
FR2146453A1 (enrdf_load_stackoverflow) 1973-03-02
IE36427L (en) 1973-01-22
DE2235783C2 (de) 1983-02-17
FR2146453B1 (enrdf_load_stackoverflow) 1978-06-30
IE36427B1 (en) 1976-10-27
DE2235783A1 (de) 1973-02-08
GB1366008A (en) 1974-09-04
SE383794B (sv) 1976-03-29
JPS5434902B1 (enrdf_load_stackoverflow) 1979-10-30

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