EP1798741B1 - Strom/Spannung nichtlinearer Widerstand - Google Patents

Strom/Spannung nichtlinearer Widerstand Download PDF

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EP1798741B1
EP1798741B1 EP06025718A EP06025718A EP1798741B1 EP 1798741 B1 EP1798741 B1 EP 1798741B1 EP 06025718 A EP06025718 A EP 06025718A EP 06025718 A EP06025718 A EP 06025718A EP 1798741 B1 EP1798741 B1 EP 1798741B1
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current
mol
voltage nonlinear
voltage
nonlinear resistor
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EP1798741A1 (de
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Hideyasu c/o Intellectual Property Division Andoh
Yasunori c/o Intellectual Property Division Kasuga
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Toshiba Corp
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Toshiba Corp
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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
    • H01C7/105—Varistor cores
    • H01C7/108—Metal oxide
    • H01C7/112—ZnO type
    • 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

Definitions

  • the present invention relates to a current/voltage nonlinear resistor whose main component is zinc oxide (ZnO), and more particularly relates to a current/voltage nonlinear resistor in which improvements have been made to the composition of sub-components contained in the main component.
  • ZnO zinc oxide
  • Overvoltage protection devices such as lightning arrestors and surge absorbers are commonly incorporated into power systems or electronic device circuitry. The purpose of these devices is to protect the power system or electronic device circuitry by removing any overvoltage that has been superimposed over the normal voltage.
  • Current/voltage nonlinear resistors are frequently used for these overvoltage protection devices.
  • a current/voltage nonlinear resistor is a resistor with the property of exhibiting substantially insulating characteristics at ordinary voltage, but exhibiting low resistance when overvoltage is applied.
  • a current/voltage nonlinear resistor is a ceramic element whose main component is zinc oxide (ZnO), and the following characteristics are required of such resistors.
  • the resistor must have nonlinear resistance characteristics, meaning that the resistance value varies greatly with changes in voltage, but also needs to have a long enough service life that no deterioration occurs when voltage is continuously applied over an extended period, energy capability characteristics that allow it to absorb lightning surges and switching surges without damage, and so forth.
  • current/voltage nonlinear resistors are seen to have a property whereby the resistance value drops when the temperature is higher. Consequently, thermal stability with respect to high temperature is also required.
  • the procedure for producing a current/voltage nonlinear resistor will now be described (see Japanese Patent Publication H4-25681 ).
  • the raw materials of the current/voltage nonlinear resistor are such that zinc oxide (ZnO) is the main component, and Bi 2 O 3 , Co 2 O 3 , MnO, Sb 2 O 3 , and NiO are added as sub-components.
  • These raw materials are thoroughly mixed along with water and a binder, then granulated with a spray dryer or the like, and these granules are molded and sintered to obtained a sinter.
  • the side faces of the sinter are coated with an insulating substance for preventing surface flashover, and this coating is heat treated to form a side face insulating layer.
  • a current/voltage nonlinear resistor is produced by polishing the two end faces of the sinter and forming electrodes.
  • a rare earth oxide is added to a current/voltage nonlinear resistor whose main component is zinc oxide (ZnO) and whose sub-components are Bi 2 O 3 , Co 2 O 3 , MnO, Sb 2 O 3 and so forth, the result of which is that the resistance value is raised and characteristics are enhanced.
  • ZnO zinc oxide
  • EP 1 150 306 A2 relates to a current/voltage non-linear resistor comprising a sintered body having ZnO as a main component, an electrode applied to a surface of the sintered body and an insulation material applied to another surface of the sintered body, said main component containing, as auxiliary components, Bi, Co, Mn, Sb, Ni and Al in the form of their oxides, wherein a Bi 2 O 3 crystalline phase in said sintered body includes an ⁇ -Bi 2 O 3 phase representing at least 80 % of the total Bi 2 O 3 phase.
  • EP 0 029 749 A1 discloses a voltage-dependent resistor of the bulk-type, comprising a sintered body consisting essentially of, as a main constituent, zinc oxide and, as additives, Bi 2 O 3 ), Co 2 O 3 , MnO 2 , Sb 2 O 3 , Cr 2 O 3 , B 2 O 3 , at least one of Al 2 O 3 , Ga 2 O 3 , NiO and SiO 2 , wherein electrodes are applied to opposite surfaces of said sintered body.
  • a reduction in the size of power transmission and conversion devices extends to reducing the size of a lightning arrestor, of course, and the following problems have been indicated when the resistance of a current/voltage nonlinear resistor was raised due to making a lightning arrestor more compact. Because the amount of surge energy absorbed increases proportionally as the resistance of a current/ voltage nonlinear resistor is raised, the heating temperature is also raised by joule heat of the current/voltage nonlinear resistor when surge energy is absorbed.
  • a current/voltage nonlinear resistor has a property whereby its resistance decreases as the temperature rises, if the temperature is too high, a drop in resistance occurs and there is greater current leakage. That is, since the decrease in the resistance of a current/voltage nonlinear resistor with increased resistance is greater when the temperature is raised, it has been indicated that there is a problem with thermal stability.
  • the present invention was proposed in light of these problems, and it is an object thereof to provide a current/voltage nonlinear resistor with which the resistance value, nonlinear resistance characteristics, and thermal stability can be improved by specifying the compositional range of sub-components, and the size of a lightning arrestor can be reduced.
  • a current voltage nonlinear resistor includes a sinter, wherein said sinter consists essentially of zinc oxide (ZnO) as the main component and bismuth (Bi), cobalt (Co), manganese (Mn), antimony (Sb), nickel (Ni), gallium (Ga), and a rare earth element (R) as sub-components in proportions, calculated as Bi 2 O 3 , Co 2 O 3 , MnO, Sb 2 O 3 , NiO, Ga 3+ , and R 2 O 3 , of 0.3 to 1.5 mol% Bi 2 O 3 , 0.3 to 2.0 mol% Co 2 O 3 , 0.4 to 3.0 mol% MnO, 0.5 to 4.0 mol% Sb 2 O 3 , 0.5 to 4.0 mol% NiO, 0.0005 to 0.02 mol% Ga 3+ , and 0.05 to 1.0 mol% R 2 O 3 , wherein the current voltage
  • the reason for specifying the sub-components to the above compositional ranges is that the inventors conducted various research into the compositions of current/voltage nonlinear resistors in an effort to achieved the above object, and as a result learned that keeping the proportions within the above ranges yields good resistance, nonlinear resistance characteristics, and thermal stability, and conversely that the above characteristics suffer when the proportions are outside the above ranges. Specifically, if the compositional proportions of the sub-components are kept within the above ranges, high resistance can be ensured and the nonlinear resistance characteristics and thermal stability are improved, and this makes it possible to attain the high level of characteristics required at the current time.
  • the present invention provides a current/voltage nonlinear resistor with which the sub-components, namely, bismuth (Bi), cobalt (Co), manganese (Mn), antimony (Sb), nickel (Ni), gallium (Ga), and a rare earth element (R), are contained in the compositional proportion ranges given above, and this affords excellent resistance, nonlinear resistance characteristics, and thermal stability, which in turn allows a current/voltage nonlinear resistor to be provided that can contribute to making lightning arrestors smaller.
  • the sub-components namely, bismuth (Bi), cobalt (Co), manganese (Mn), antimony (Sb), nickel (Ni), gallium (Ga), and a rare earth element (R)
  • Tables 1 to 5 show evaluation indicators and contained amounts of current/voltage nonlinear resistors produced with varying amounts of sub-components contained.
  • those marked with an asterisk have sub-components that are outside the compositional ranges pertaining to the present invention, and are comparative samples produced for the sake of comparison.
  • those not marked with an asterisk meanwhile, have sub-components within the compositional ranges corresponding to the present invention.
  • FIG. 1 is a cross section of the current/voltage nonlinear resistor pertaining to this embodiment.
  • zinc oxide (ZnO) was used as the main component.
  • Bismuth (Bi), cobalt (Co), manganese (Mn), antimony (Sb), nickel (Ni), and gallium (Ga), were used as sub-components, and the final amounts in which these were contained, calculated as Bi 2 0 3 , Co 2 O 3 , MnO, Sb 2 0 3 , NiO, and Ga 3+ were within the following ranges.
  • the product contained 0.3 to 1.5 mol% Bi 2 0 3 , 0.3 to 2.0 mol% Co 2 O 3 , 0.4 to 3.0 mol% MnO, 0.5 to 4.0 mol% % Sb 2 0 3 , 0.5 to 4.0 mol% NiO, and 0.0005 to 0.02 mol% Ga 3+ .
  • At least one type of rare earth oxide (R) selected from about dysprosium (Dy), europium (Eu), erbium (Er), thulium (Tm), gadolinium (Gd), yttrium (Y), holmium (Ho), and ytterbium (Yb) were contained in an amount of 0.05 to 1.0 mol%, calculated as R 2 O 3 .
  • Bi 2 O 3 , Co 2 O 3 , MnO, Sb 2 O 3 , NiO, Dy 2 O 3 , and Ga 3+ or Al 3+ were measured out as sub-components in specific amounts with respect to the ZnO main component such that the amounts in which the components were contained in the current/voltage nonlinear resistors ultimately obtained were as indicated for sample numbers 1 to 44 in Tables 1 and 2.
  • These raw materials were mixed in a mixer along with water and an organic binder, and each slurry was adjusted to a uniform consistency.
  • the Ga 3+ or Al 3+ here was added as a nitrate aqueous solution.
  • each of the slurries thus obtained was spray granulated in a spray dryer to produce a granulated powder with a grain size of about 100 ⁇ m.
  • the granulated powder thus obtained was put in a metal mold and pressed into a disk with a diameter of 125 mm and a thickness of 30 mm, and this molded disk was heated to 500°C to remove the organic binder that had been added.
  • the disk was fired for 2 hours at 1100°C to obtain the sinter 1 shown in FIG. 1 .
  • the side faces of the sinter 1 were coated with an inorganic insulating substance, and these coatings were heat treated to form side face insulating layers 2.
  • the upper and lower end faces of the sinter 1 provided with the side face insulating layers 2 were polished to a specific thickness, after which electrodes 3 were thermal sprayed onto the polished faces of the sinter 1 to produce a current/voltage nonlinear resistor.
  • the characteristics of the various current/voltage nonlinear resistors produced by the above procedure were evaluated as follows. First, the resistance of the current/voltage nonlinear resistor was evaluated by measuring the initial operating voltage of the current/voltage nonlinear resistor (the voltage when 1 mA of AC current was applied; V 1mA ). The higher the initial operating voltage, the fewer current/voltage nonlinear resistors that need to be stacked in a lightning arrestor, so this voltage is effective as an index for ascertaining how compact a lightning arrestor can be made.
  • V 10kA The voltage when a 10 kA impulse current of 8 x 20 ⁇ s was applied (V 10kA ) was measured, and the ratio of this to the initial operating voltage V 1mA (V 10kA /V 1mA ) was evaluated as a nonlinearity coefficient. The smaller the value of this nonlinearity coefficient, the better the nonlinear resistance characteristics.
  • the thermal stability of the current/voltage nonlinear resistor was evaluated by measuring the resistance leakage current when AC voltage that was 90% of the initial operating voltage was applied in a 200°C thermostatic tank. Specifically, the less leakage current at high temperature there is at 200°C, the better the thermal stability.
  • the compositions of ten elements with each added component composition were measured, and the average thereof was used for the compositional value. The measurement results are given in Tables 1 and 2.
  • the current/voltage nonlinear resistors with sample numbers not marked with an asterisk in Tables 1 and 2 were within the compositional ranges specified in the claims of the present invention, and therefore exhibited excellent results for initial operating voltage, nonlinearity coefficient, and leakage current at high temperature.
  • the current/voltage nonlinear resistors pertaining to this embodiment can be considered to have high resistance and excellent nonlinear resistance characteristics and thermal stability.
  • Bi 2 O 3 is a component that is present at the boundary of the zinc oxide (ZnO), which is the main component of the sinter, and is responsible for nonlinear resistance characteristics. The role of this component is to promote the growth of ZnO crystal grains. If we compare sample numbers 1 to 6 here, we see that when the amount of Bi 2 O 3 was less than 0.3 mol% (sample number 1), the material was in the liquid phase during sintering, and the amount of Bi 2 0 3 was inadequate to improve sintering.
  • ZnO zinc oxide
  • Sb 2 O 3 is a component that controls and makes uniform the growth of ZnO crystal grains during sintering by forming spinel (Zn 7 Sb 2 O 12 ) particles along with zinc oxide (ZnO). Its role is to improve nonlinear resistance characteristics and, at the same time, suppress the growth of ZnO crystal grains.
  • sample numbers 3 and 7 to 12 A comparison of sample numbers 3 and 7 to 12 reveals that if the Sb 2 O 3 content is less than 0.5 mol% (sample number 7), there will be too few spinel particles capable of suppressing grain growth during sintering, so excellent characteristics cannot be obtained in terms of initial operating voltage and nonlinearity. If the amount of Sb 2 O 3 is over 4 mol% (sample number 12), however, it will act as an insulating component in the sinter, and there will be too many spinel particles, so excellent characteristics cannot be obtained in terms of nonlinearity and leakage current at high temperature.
  • MnO is a component that primarily forms a solid solution with spinel particles and improves nonlinear resistance characteristics.
  • a comparison of sample numbers 3 and 13 to 18 reveals that if the MnO content is less than 0.4 mol% (sample number 13), the electrical characteristics are unstable at the ZnO grain boundary, so excellent nonlinearity cannot be obtained. If the amount of MnO is over 3 mol% (sample number 18), however, here again it is impossible to obtain excellent nonlinearity characteristics.
  • NiO is similar to MnO in that it primarily forms a solid solution with spinel particles and improves nonlinear resistance characteristics.
  • a comparison of sample numbers 3 and 19 to 24 reveals that if the NiO content is less than 0.5 mol% (sample number 19), the very little NiO will form a solid solution with the spinel particles, so excellent initial operating voltage and nonlinearity cannot be obtained. If the amount of NiO is over 4 mol% (sample number 24), however, the electrical characteristics are unstable at the ZnO grain boundary, so excellent nonlinearity characteristics and leakage current at high temperature characteristics cannot be obtained.
  • Co 2 O 3 also is a component that primarily forms a solid solution with spinel particles and improves nonlinear resistance characteristics.
  • a comparison of sample numbers 3 and 25 to 30 reveals that if the Co 2 O 3 content is less than 0.3 mol% (sample number 25), the electrical characteristics are unstable at the ZnO grain boundary, so excellent nonlinearity cannot be obtained, but if the amount of Co 2 O 3 is over 2 mol% (sample number 30), here again the electrical characteristics are unstable at the ZnO grain boundary, making it impossible to obtain excellent nonlinearity characteristics or leakage current at high temperature characteristics.
  • Ga 3+ serves to improve nonlinear resistance characteristics by forming a solid solution in the ZnO particles and lowering the electrical resistance of the ZnO particles.
  • Aluminum (Al) has often been used in prior art as a component with a similar purpose, but improving nonlinear resistance characteristics by adding gallium gives a current/voltage nonlinear resistor with better thermal stability than by adding aluminum.
  • sample numbers 3 and 31 to 38 A comparison of sample numbers 3 and 31 to 38 reveals that if the Ga 3+ content is less than 0.0005 mol% (sample number 31), not enough Ga 3+ will form a solid solution in the ZnO particles in the sinter, so the electrical resistance of the ZnO particles will be high and excellent nonlinearity cannot be obtained.
  • Ga 3+ is over 0.02 mol% (sample number 37), however, the Ga 3+ will precipitate at the ZnO grain boundary and adversely affect the electrical characteristics of the ZnO grain boundary, so excellent nonlinearity cannot be obtained. Furthermore, compared to when Al 3+ is added (sample number 38), adding Ga 3+ allows better leakage current at high temperature characteristics to be obtained.
  • sample numbers 3 and 39 to 44 A comparison of sample numbers 3 and 39 to 44 reveals that if the Dy 2 O 3 content is less than 0.3 mol% (sample number 39), there will not be enough Dy 2 O 3 to have the effect of suppressing grain growth, so excellent initial operating voltage and nonlinearity cannot be obtained. If the amount of Dy 2 O 3 is over 1.0 mol% (sample number 44), however, the electrical characteristics will be unstable at the ZnO grain boundary, making it impossible to obtain excellent characteristics in terms of nonlinearity or leakage current at high temperature.
  • an oxide of dysprosium (Dy) was used as a rare earth oxide in this embodiment, but oxides of other rare earth elements, namely, europium (Eu), erbium (Er), thulium (Tm), gadolinium (Gd), yttrium (Y), holmium (Ho), and ytterbium (Yb), may also be used, and these will have the same effect as an oxide of dysprosium (Dy). Also, as long as the amount in which the various rare earth oxides are contained ends up being within a range of 0.05 to 1.0 mol%, the combination thereof may be selected as desired.
  • zinc oxide (ZnO) is the main component and the final amounts of sub-components are within the ranges given above, which makes it possible to obtain a current/voltage nonlinear resistor that has high resistance and excellent thermal stability and nonlinear resistance characteristics. Accordingly, the number of stacked layers of current/voltage nonlinear resistor can be reduced while maintaining high reliability, and this contributes to making a lightning arrestor smaller.
  • This embodiment is characterized by being composed of a sinter containing 0.005 to 0.05 wt% silver (Ag), calculated as Ag 2 O.
  • Bi 2 O 3 (0.5 mol%), Co 2 O 3 (1.0 mol%), MnO (1.0 mol%), Sb 2 O 3 (2 mol%), NiO (2 mol%), Dy 2 O 3 (0.5 mol%), and Ga 3+ (0.003 mol% as a nitrate aqueous solution) were measured out as sub-components in the final proportions given in parentheses above, and these components were added to the ZnO main component.
  • Ag 2 O was further added to this base composition so as to be contained in an amount of 0.001 to 0.1 wt%, and the current/voltage nonlinear resistors of sample numbers 45 to 50 shown in Table 3 were produced by the method described in the first embodiment above.
  • the current/voltage nonlinear resistors of sample numbers 45 and 50 which are marked with an asterisk in Table 3, have compositions outside the scope of the claims of the present invention.
  • the characteristics of the comparative samples indicate that the percentage change in leakage current is a positive value, and the service life characteristics are low.
  • the added amount of silver, calculated as Ag 2 O was less than 0.005 wt%, there was no effect of improving service life characteristics.
  • the amount was over 0.05 wt%, though, this had the opposite effect of causing the service life characteristics to deteriorate.
  • adding silver in an amount of 0.005 to 0.05 wt%, calculated as Ag 2 O reduces the change over time in leakage current and improves the service life characteristics. Furthermore, in this embodiment, the effect of adding silver on the service life characteristics was only discussed for the base composition given in the Constitution and Production Procedure above, but the same effect will be obtained as long as the composition is within the range of the base composition given in Claim 1.
  • This embodiment is characterized by being composed of a sinter containing 0.005 to 0.05 wt% boron (B), calculated as B 2 O 3 .
  • B 2 O 3 was further added to this base composition so as to be contained in an amount of 0.001 to 0.1 wt%, and the current/voltage nonlinear resistors of sample numbers 51 to 56 shown in Table 4 were produced by the method described in the first embodiment above. That is, in the third embodiment, B 2 O 3 was contained, instead of the Ag 2 O used in the second embodiment, in amounts between 0.001 and 0.1 wt%.
  • Table 4 shows the percentage change in leakage current in this third embodiment.
  • Table 4 Sample number B 2 O 3 content (wt%) Percentage change in leakage current (%) 51* 0.0001 9.8 52 0.005 -21 53 0.010 -3.5 54 0.020 -8.2 55. 0.050 -6.9 56* 0.100 12.5
  • the current/voltage nonlinear resistors of sample numbers 51 and 56 which are marked with an asterisk in Table 4, have compositions outside the scope of the claims of the present invention. As shown in Table 4, the characteristics of the comparative samples indicate that the percentage change in leakage current is a positive value, and the service life characteristics are low.
  • the service life characteristics were low when the added amount of boron, calculated as B 2 O 3 , was less than 0.005 wt%, and when it was more than 0.05 wt%.
  • the percentage change in leakage current was a negative value (see Table 4), and current/voltage nonlinear resistors with excellent service life characteristics were obtained.
  • adding boron in an amount of 0.005 to 0.05 wt%, calculated as B 2 O 3 improves the service life characteristics, just as in the second embodiment. Furthermore, in this embodiment, the effect of adding boron on the service life characteristics was only discussed for the above-mentioned base composition, but the same effect will be obtained as long as the composition is within the range of the base composition given in Claim 1. Also, instead of adding silver or boron alone, both may be added at the same time, as long as the combined amount is between 0.005 and 0.05 wt%.
  • Bi 2 O 3 (0.5 mol%), Co 2 O 3 (1.0 mol%), MnO (1.0 mol%), Sb 2 0 3 (2 mol%), NiO (2 mol%), Dy 2 0 3 (0.5 mol%), and Ga 3+ (0.003 mol%) were measured out as sub-components in the final proportions given in parentheses above, these components were added to the ZnO main component, and current/voltage nonlinear resistors were produced by the method described in the first embodiment above.
  • This embodiment is characterized in that Ga 3+ is added as a nitrate aqueous solution.
  • the stability of the resistance value is evaluated in this fourth embodiment. Specifically, the initial operating voltage (V 1mA ) was measured for 100 current/voltage nonlinear resistors in which Ga 3+ had been added as a nitrate aqueous solution, and the standard deviation of this initial operating voltage was calculated. As a comparative example, the initial operating voltage (V 1mA ) was measured for 100 current/voltage nonlinear resistors in which Ga 3+ had been added not as an aqueous solution, but as an oxide, and the standard deviation of this initial operating voltage was calculated.
  • the standard deviation was calculated, and as a result the standard deviation of V 1mA when the Ga 3+ was added as a nitrate aqueous solution was 585, while the standard deviation of V 1mA when the Ga 3+ was added as an oxide was 2406. Specifically, a current/voltage nonlinear resistor with vastly less variance in its characteristics could be obtained by adding the Ga 3+ as a nitrate aqueous solution.
  • gallium (Ga) was added in an extremely small amount, when gallium oxide (Ga 2 O 3 ), which is an oxide of gallium (Ga), was added, it was difficult to mix uniformly with the other raw materials, and there was a great deal of variance in the characteristics. In contrast, when gallium nitrate (Ga(N0 3 ) 3 ), which is a water-soluble gallium raw material, was added, it mixed as gallium ions with the other raw materials, which is believed to be why the characteristics were so stable.
  • Ga 3+ was added as a nitrate, with the added amount varied, and the current/voltage nonlinear resistors of sample numbers 57 to 71 in Table 5 were produced by the method described in the first embodiment above.
  • the disk diameter of the current/voltage nonlinear resistors was either 35, 60, or 100 mm, and the added amount of Ga 3+ was varied with the disk diameter.
  • the nonlinearity (V 10kA /V 1mA ) of these current/voltage nonlinear resistors was evaluated by the method given in the first embodiment above, and the results are given in Table 5.
  • the coefficient A in Table 5 is a coefficient in the following relational formula with the added amount of Ga 3+ .
  • FIG. 2 shows the relation between the coefficient A and nonlinearity.
  • nonlinearity obviously varies with the amount in which gallium (Ga) is added.
  • Ga gallium
  • added amount of gallium at which nonlinearity is good varies with the diameter of the disk. This is because the current density in the current/voltage nonlinear resistor varies with the disk diameter, and the optimal added amount of gallium is within the range of the relational formula given above.
  • the present invention is not limited to the embodiments given above, and various modifications are possible as long as the sub-components bismuth (Bi), cobalt (Co), manganese (Mn), antimony (Sb), nickel (Ni), gallium (Ga), and a rare earth element (R), and silver (Ag) and boron (B) are within the compositional range given in the claims.

Claims (5)

  1. Strom/Spannung-nichtlinearer Widerstand, der einen Sinterkörper (1) umfasst, wobei der Sinterkörper im Wesentlichen aus Zinkoxid (ZnO) als Hauptkomponente und Bismuth (Bi), Cobalt (Co), Mangan (Mn), Antimon (Sb), Nickel (Ni), Gallium (Ga) und einem Seltenerdelement (R) als Nebenkomponenten besteht,
    wobei die Nebenkomponenten, berechnet als Bi2O3, Co2O3, MnO, Sb2O3, NiO, Ga3+ und R2O3, in den folgenden Anteilen enthalten sind:
    Bi2O3: 0,3 bis 1,5 mol-%
    Co2O3: 0,3 bis 2,0 mol-%
    MnO: 0,4 bis 3,0 mol-%
    Sb2O3: 0,5 bis 4,0 mol-%
    NiO: 0,5 bis 4,0 mol-%
    Ga3+: 0,0005 bis 0,02 mol-% und
    R2O3: 0,05 bis 1,0 mol-%,
    wobei der Strom/Spannung-nichtlineare Widerstand in der Form einer Scheibe vorliegt, wodurch die Beziehung zwischen der zugesetzten Ga3+-Menge und dem Durchmesser der Scheibe derart ist, dass
    die zugesetzte Ga3+-Menge (mol-%) ≤ (A - 0,042 × D)/1000 ist
    (wobei A = 5 bis 14 und D = Scheibendurchmesser (mm)).
  2. Strom/Spannung-nichtlinearer Widerstand nach Anspruch 1, wobei der Sinterkörper (1) ferner 0,005 bis 0,05 Gew.-% Silber (Ag), berechnet als Ag2O3, enthält.
  3. Strom/Spannung-nichtlinearer Widerstand nach Anspruch 1, wobei der Sinterkörper (1) ferner 0,005 bis 0,05 Gew.-% Bor (B), berechnet als B2O3, enthält.
  4. Strom/Spannung-nichtlinearer Widerstand nach einem der Ansprüche 1 bis 3, wobei (R) mindestens ein Element der Gruppe, bestehend aus Dysprosium (Dy), Europium (Eu), Erbium (Er), Thulium (Tm), Gadolinium (Gd), Yttrium (Y), Holmium (Ho) und Ytterbium (Yb), ist.
  5. Strom/Spannung-nichtlinearer Widerstand nach einem der Ansprüche 1 bis 4, wobei als zuzusetzendes Gallium (Ga)-Ausgangsmaterial ein wasserlösliches Ausgangsmaterial verwendet wird.
EP06025718A 2005-12-19 2006-12-12 Strom/Spannung nichtlinearer Widerstand Active EP1798741B1 (de)

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US8729809B2 (en) * 2009-09-08 2014-05-20 Denovo Lighting, Llc Voltage regulating devices in LED lamps with multiple power sources
JP2012038928A (ja) * 2010-08-06 2012-02-23 Toshiba Corp 避雷器
DE102014107040A1 (de) * 2014-05-19 2015-11-19 Epcos Ag Elektronisches Bauelement und Verfahren zu dessen Herstellung
KR101690720B1 (ko) * 2015-07-31 2016-12-28 동의대학교 산학협력단 망간/코발트/비스무스/디스프로슘이 첨가된 산화아연 바나듐계 바리스터 및 그 제조방법
DE102016104990A1 (de) 2016-03-17 2017-09-21 Epcos Ag Keramikmaterial, Varistor und Verfahren zum Herstellen des Keramikmaterials und des Varistors
JP6937390B2 (ja) * 2018-01-26 2021-09-22 株式会社東芝 電流−電圧非直線抵抗体用材料、電流−電圧非直線抵抗体およびその製造方法

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DE602006019816D1 (de) 2011-03-10
EP1798741A1 (de) 2007-06-20
KR20070065215A (ko) 2007-06-22

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