EP0065806B1 - Spannungsabhängiger Widerstand und Verfahren zu seiner Herstellung - Google Patents

Spannungsabhängiger Widerstand und Verfahren zu seiner Herstellung Download PDF

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Publication number
EP0065806B1
EP0065806B1 EP82200615A EP82200615A EP0065806B1 EP 0065806 B1 EP0065806 B1 EP 0065806B1 EP 82200615 A EP82200615 A EP 82200615A EP 82200615 A EP82200615 A EP 82200615A EP 0065806 B1 EP0065806 B1 EP 0065806B1
Authority
EP
European Patent Office
Prior art keywords
metal oxide
sintered body
voltage
metal
dependent resistor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP82200615A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0065806A3 (en
EP0065806A2 (de
Inventor
Detlev Dr. Hennings
Axel Dr. Schnell
Herbert Schreinemacher
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Philips Intellectual Property and Standards GmbH
Koninklijke Philips NV
Original Assignee
Philips Patentverwaltung GmbH
Philips Gloeilampenfabrieken NV
Koninklijke Philips Electronics NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Philips Patentverwaltung GmbH, Philips Gloeilampenfabrieken NV, Koninklijke Philips Electronics NV filed Critical Philips Patentverwaltung GmbH
Publication of EP0065806A2 publication Critical patent/EP0065806A2/de
Publication of EP0065806A3 publication Critical patent/EP0065806A3/de
Application granted granted Critical
Publication of EP0065806B1 publication Critical patent/EP0065806B1/de
Expired legal-status Critical Current

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Classifications

    • 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
    • H01C7/115—Titanium dioxide- or titanate type

Definitions

  • the invention relates to a voltage-dependent resistor with a ceramic sintered body based on a polycrystalline, alkaline earth metal titanate doped with a small amount of a metal oxide to produce an N-type conductivity, with electrodes arranged on opposing surfaces, and a method for producing such a resistor.
  • a voltage-dependent resistor is known from German patent application P 30 19 969.0, which is based on N-doped strontium titanate, to which a small proportion of a lead germanate phase was added before sintering, which leads to the formation of insulating grain boundary layers in the polycrystalline structure of the sintered body.
  • This known resistance is because of its relatively high field strength - a current density z. B. of about 3 mAlcm 2 results only in fields of about 6 kV / cm - can only be used to a limited extent; he is e.g. B. Not suitable for modern semiconductor circuits that work with low voltages.
  • the invention has for its object to develop a voltage-dependent resistor according to the preamble of the claim and a method for its production such that a voltage-dependent resistor with a low field strength is obtained.
  • a method for producing a voltage-dependent resistor with a ceramic sintered body based on a polycrystalline, alkaline earth metal titanate doped with a small amount of a metal oxide to produce an N-type conductivity is characterized in that the sintered body with a perovskite structure is first produced in a reducing atmosphere by producing it Sintered body is then covered on its surface to form an insulating layer on the grain edge layers of the polycrystalline perovskite phase with a suspension containing at least one metal oxide or a metal oxide compound, the metal oxide or metal oxide compound having a lower melting point than the perovskite phase, the polycrystalline perovskite phase on the other Grain edge layers well wetted and showing reversible breakthrough phenomena during field strengths during operation of the component, after which the sintered body in an oxidizing atmosphere, preferably in air, b at a temperature which is above the melting point of the suspension component (s).
  • the alkaline earth metal titanate is reacted by reacting SrC0 3 with Ti0 2 in a molar ratio of 1: 1.001 to 1: 1.02 with the addition of the doping metals in the form of their oxides in an amount of 0.05 to a maximum of 60 mol% of the constituent to be substituted after grinding and presintering for 15 h at 1,150 ° C. in air.
  • this is made from 90 for 4 h at a temperature of 1,460 ° C. in a reducing atmosphere consisting of mixed gas saturated with water vapor Vol.% N 2 and 10 vol.% H 2 sintered.
  • La 2 0 3 , Nb 2 0 5 or W0 3 are used as the doping metal oxide and Bi 2 0 3 as the metal oxide to be diffused in, or lead germanate Pb 5 Ge 3 O 11 is used as the metal oxide compound to be diffused in.
  • La 3 + , Nb s + and W 6+ ions have proven to be particularly suitable for N doping.
  • other dopings are also conceivable, e.g. B. other rare earth metal ions such as Sm 3+ or Y 3+ ; instead of Nb 5+ , Ta 5+ , As 5+ or Sb 5+ and instead of W 6+ , Mo 6+ and U 6+ can be used.
  • the doping ions are installed either on Sr or Ti sites in the perovskite lattice.
  • a suspension with at least one metal oxide that melts relatively low with respect to the sintered body or at least one metal oxide compound that melts relatively low with respect to the sintered body e.g. B. Bi 2 0 3 or lead germanate Pb 5 Ge 3 O 11 , applied in an organic binder and baked under oxidizing conditions at temperatures around or above 900 ° C, the applied molten metal oxide or the metal oxide compound diffuses preferably along the grain boundaries into the semiconducting ceramic and creates highly insulating grain boundary layers there.
  • the voltage across a varistor of composition is Sr (Ti 0.996 W 0.004 ) O 3 .
  • 0.0TiO 2 with a diffused phase of Bi 2 O 3 at 1 mA and 30 mA depending on the temperature.
  • a liquid sintering phase is formed with the SrTi0 3 at a sintering above 1 400 ° C - it can be assumed that this is the eutectic SrTi0 3 -Ti0 2 occurring at ⁇ 1 440 ° C, which is caused by the addition of Dopants can also occur at lower temperatures.
  • a liquid sintering phase of this type promotes coarse grain growth, which, as already stated, is desirable.
  • the raw materials are weighed in an amount corresponding to the desired composition and 2 hours in a ball mill, e.g. B. agate, wet mixed. This is followed by presintering at 1,150 ° C for 15 h.
  • the pre-sintered powders are ground again wet (1 h in a ball mill, e.g. made of agate).
  • the millbase is then dried, and the powders thus obtained are then removed using a suitable binder, e.g. B. a 10% aqueous polyvinyl alcohol solution, granulated.
  • the granules are molded articles suitable for ceramic resistors, for. B.
  • sintering it is remarkable that coarse-grained structures preferably occur at sintering temperatures above 1,440 ° C.
  • the reducing sintering should take place in a tightly closing furnace, e.g. B. a tube furnace is suitable. Excess reducing gas should expediently flow out via a bubble counter in order to create a constant sintering atmosphere.
  • Sintered bodies produced in this way are semiconducting and no longer show open porosity.
  • the insulating grain edge layers are by diffusing at least one molten metal oxide or at least one metal oxide compound, for. B. Bi 2 0 3 or lead germanate Pb 5 Ge 3 O 11 , generated in air.
  • the metal oxide or the metal oxide compound is first suspended in a binder based on polyvinyl acetate and applied to the already sintered ceramic.
  • the suspended metal oxide or the suspended metal oxide compound is then baked into the sintered body by a tempering process at a temperature at which they are in the molten state.
  • the minimum annealing temperature was a temperature slightly above the melting point of the metal oxide used or the used metal oxide compound determined.
  • the amounts of the metal oxides or metal oxide compounds diffused into the sintered body were determined in parallel experiments by weighing the sintered bodies before applying the suspension, after burning out the binder in air at 600 ° C. and after tempering.
  • the heating-up and cooling-down times were uniformly 100 minutes for all tests.
  • electrodes made of suitable metals, preferably gold, e.g. B. by vapor deposition.
  • a suitable adhesive layer as an intermediate layer between the ceramic and the electrode metal on the ceramic sintered body; e.g. B. a Cr-Ni layer is suitable.
  • x results from the solubility limit of La in the perovskite phase.
  • Different operating voltages of the finished component can, however, be set by different thickness of the components.
  • the sintered bodies treated with a diffusion phase made of Bi 203 show the normal VDR dependence superimposed on a negative resistance range, ie, the voltage across the component decreases with increasing current, which can be advantageous in certain applications, since this is practically a value for the current index ⁇ ⁇ 0 corresponds (for this, reference is made to FIG. 2).
  • An overvoltage is thereby not only limited to a certain value, but additional energy is absorbed in the component as the current decreases as the current increases.
  • This property of the sintered body treated with Bi 2 0 3 is only partially caused by the heating and the associated decrease in resistance of the components. This is shown in FIG. 3, in which the voltage across the component was plotted at 1 mA and 30 mA as a function of the temperature. The 30 mA values were measured by short current pulses, so that self-heating by the measuring current is negligible.

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Compositions Of Oxide Ceramics (AREA)
  • Thermistors And Varistors (AREA)
EP82200615A 1981-05-29 1982-05-19 Spannungsabhängiger Widerstand und Verfahren zu seiner Herstellung Expired EP0065806B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3121289 1981-05-29
DE19813121289 DE3121289A1 (de) 1981-05-29 1981-05-29 Spannungsabhaengiger widerstand und verfahren zu seiner herstellung

Publications (3)

Publication Number Publication Date
EP0065806A2 EP0065806A2 (de) 1982-12-01
EP0065806A3 EP0065806A3 (en) 1983-05-04
EP0065806B1 true EP0065806B1 (de) 1985-11-21

Family

ID=6133437

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82200615A Expired EP0065806B1 (de) 1981-05-29 1982-05-19 Spannungsabhängiger Widerstand und Verfahren zu seiner Herstellung

Country Status (4)

Country Link
US (2) US4581159A (enrdf_load_stackoverflow)
EP (1) EP0065806B1 (enrdf_load_stackoverflow)
JP (1) JPS57199202A (enrdf_load_stackoverflow)
DE (2) DE3121289A1 (enrdf_load_stackoverflow)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59188103A (ja) * 1983-04-08 1984-10-25 株式会社村田製作所 電圧非直線抵抗体用磁器組成物
DE3523681A1 (de) * 1985-07-03 1987-01-08 Philips Patentverwaltung Verfahren zur herstellung keramischer sinterkoerper
JPH0670884B2 (ja) * 1986-12-27 1994-09-07 株式会社住友金属セラミックス マイクロ波用誘電体磁器組成物
US5225126A (en) * 1991-10-03 1993-07-06 Alfred University Piezoresistive sensor
DE10026258B4 (de) * 2000-05-26 2004-03-25 Epcos Ag Keramisches Material, keramisches Bauelement mit dem keramischen Material und Verwendung des keramischen Bauelements
DE102007010239A1 (de) * 2007-03-02 2008-09-04 Epcos Ag Piezoelektrisches Material, Vielschicht-Aktuator und Verfahren zur Herstellung eines piezoelektrischen Bauelements
DE102009058795A1 (de) * 2009-12-18 2011-06-22 Epcos Ag, 81669 Piezoelektrisches Keramikmaterial, Verfahren zur Herstellung des piezoelektrischen Keramikmaterials, piezoelektrisches Vielschichtbauelement und Verfahren zur Herstellung des piezoelektrischen Vielschichtbauelements
CN111542900B (zh) 2017-12-01 2022-04-15 京瓷Avx元器件公司 低纵横比压敏电阻

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL301822A (enrdf_load_stackoverflow) * 1963-12-13
US3561106A (en) * 1968-07-03 1971-02-09 Univ Iowa State Res Found Inc Barrier layer circuit element and method of forming
US3933668A (en) * 1973-07-16 1976-01-20 Sony Corporation Intergranular insulation type polycrystalline ceramic semiconductive composition
GB1556638A (en) * 1977-02-09 1979-11-28 Matsushita Electric Ind Co Ltd Method for manufacturing a ceramic electronic component
US4237084A (en) * 1979-03-26 1980-12-02 University Of Illinois Foundation Method of producing internal boundary layer ceramic compositions
JPS56169316A (en) * 1980-05-30 1981-12-26 Matsushita Electric Ind Co Ltd Composition functional element and method of producing same
JPS5735303A (en) * 1980-07-30 1982-02-25 Taiyo Yuden Kk Voltage vs current characteristic nonlinear semiconductor porcelain composition and method of producing same
US4347167A (en) * 1980-10-01 1982-08-31 University Of Illinois Foundation Fine-grain semiconducting ceramic compositions
US4419310A (en) * 1981-05-06 1983-12-06 Sprague Electric Company SrTiO3 barrier layer capacitor
JPS58103116A (ja) * 1981-12-16 1983-06-20 太陽誘電株式会社 コンデンサ用半導体磁器
JPS5891602A (ja) * 1981-11-26 1983-05-31 太陽誘電株式会社 電圧非直線磁器組成物
US4436650A (en) * 1982-07-14 1984-03-13 Gte Laboratories Incorporated Low voltage ceramic varistor

Also Published As

Publication number Publication date
US4692289A (en) 1987-09-08
DE3267542D1 (en) 1986-01-02
JPS57199202A (en) 1982-12-07
DE3121289A1 (de) 1982-12-23
JPH0236041B2 (enrdf_load_stackoverflow) 1990-08-15
US4581159A (en) 1986-04-08
EP0065806A3 (en) 1983-05-04
EP0065806A2 (de) 1982-12-01

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