And Trivalent Metal Oxide Patents (Class 501/139)
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Patent number: 5688732Abstract: The present invention relates to dielectric ceramic compositions for microwave applications consisting of BaO, PbO, Nd.sub.2 O.sub.3, CeO.sub.2, La.sub.2 O.sub.3 and TiO.sub.2 or consisting of compositions including these elements and having a composition formula (I).x(Ba.sub.1-.alpha. Pb.sub..alpha.)O-y?Nd.sub.2 O.sub.3(1-.beta.-.gamma.) CeO.sub.2(.beta.) La.sub.2 O.sub.3(.gamma.) !-zTiO.sub.2 (I)wherein mol %, 6.ltoreq.x.ltoreq.20, 10.ltoreq.y.ltoreq.20, 60.ltoreq.z.ltoreq.75, x+y+z=100; and 0<.alpha..ltoreq.0.5, 0.ltoreq..beta..ltoreq.0.2, 0.ltoreq..gamma..ltoreq.0.2 and 0<1-.beta.-.gamma.<1. These dielectric ceramic compositions for microwave applications have a dielectric constant above 90 at room temperature, a temperature coefficient at the resonant frequency within +5 ppm/.degree.C.Type: GrantFiled: November 15, 1995Date of Patent: November 18, 1997Assignee: Electronics & Telecommunications Research Inst.Inventors: Jung-Rae Park, Tae-Hong Kim, Suk-Jin Lee, Sang-Seok Lee, Tae-Goo Choi
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Patent number: 5686367Abstract: A semiconducting ceramic composition having a positive temperature coefficient and a process for production thereof. The semiconducting ceramic composition comprises a barium titanate semiconducting ceramic composition containing silicon oxide and manganese, the semiconducting ceramic composition further comprising sodium in an amount of from 0.0005 to 0.02 wt % based on the amount of the barium titanate semiconducting ceramic composition.Type: GrantFiled: February 7, 1996Date of Patent: November 11, 1997Assignee: TDK CorporationInventor: Kouji Hayashi
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Patent number: 5650367Abstract: A dielectric ceramic composition containing, per 100 parts by weight of BaTiO.sub.3, at least either one of Nb.sub.2 O.sub.5 or Ta.sub.2 O.sub.5 in an amount of from 0.8 to 3.5 parts by weight, MgO in an amount of from 0.06 to 0.7 parts by weight, oxides of rare earth elements in an amount of from 0.005 to 0.520 parts by weight, and MnO in an amount of from 0.01 to 0.30 parts by weight in the form of MnCO.sub.3, the molar ratio of MgO to either Nb.sub.2 O.sub.5 or Ta.sub.2 O.sub.5 being from 0.5 to 2.2. The dielectric ceramic composition has a dielectric constant of not smaller than 2500, is fired at a temperature of not higher than 1300.degree. C., exhibits a change of capacitance depending upon the temperature satisfying X7R of the IEA Standards, a dielectric loss of not larger than 2.5%, a small voltage dependence, and an insulation resistance of not smaller than 10.sup.4 M.OMEGA., and is suited as a material for producing ceramic capacitors and resonators.Type: GrantFiled: October 19, 1995Date of Patent: July 22, 1997Assignee: Kyocera CorporationInventors: Nobuyoshi Fujikawa, Yoshihiro Fujioka, Yasushi Yamakuchi, Shin-ichi Osawa, Hiroshi Ojima
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Patent number: 5650368Abstract: A dielectric ceramic composition used for a ceramic capacitor for temperature compensation, a resonator and the like. The dielectric ceramic composition comprises a composite oxide containing, as metal elements, main components of (i) barium, (ii) rare earth elements such as neodymium (Nd) or Nd and Sm in combination, and (iii) elements of the Group IV of periodic table such as titanium (Ti) or Ti and Zr or Sn in combination, and an assistant component of manganese, wherein the main components comprise from 7.5 to 16.25 mol % of a barium oxide, from 16.75 to 23.75 mol % of an oxide of rare earth element, and from 67 to 71.66 mol % of an oxide of element of the Group IV reckoned as a molar composition of the ternary-component-based oxide, the manganese component is contained in an amount of from 0.01 to 0.5% by weight reckoned as MnCO.sub.3 with respect to the main components, and sodium component which is an impurity is contained in an amount of not larger than 0.Type: GrantFiled: July 26, 1996Date of Patent: July 22, 1997Assignee: Kyocera CorporationInventors: Yuji Tateishi, Akihiro Kaneuchi, Nobuyoshi Fujikawa
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Patent number: 5646080Abstract: A sinterable dielectric ceramic powder composition comprising 95 to 98 parts by weight of a major ingredient consisting of 97.0 to 99.5 mole % barium titanate, 0.5 to 3.0 mole % magnesium oxide or a precursor therefor and 0 to 2.0 mole % manganese oxide or a precursor therefor and 0 to 0.2 mole % cobalt oxide or a precursor therefor; 2 to 5 parts by weight of a minor ingredient consisting of a ternary mixture of 15 to 30 mole % barium oxide or a precursor therefor, 15 to 30 mole % silicon dioxide or a precursor therefor and 40 to 70 mole % calcium titanate, which composition can be fabricated into multilayer ceramic capacitors with nickel, nickel alloy, palladium or palladium/silver alloy inner electrodes, the so formed capacitors having a variation of capacitance with temperature of less than .+-.20% over the range -55.degree. C. to 140.degree. C. as compared to the value at 25.degree. C. and not containing any second phases after sintering.Type: GrantFiled: November 20, 1995Date of Patent: July 8, 1997Assignee: Tam Ceramics, Inc.Inventors: Mike Ssu-Hai Chu, John Bultitude, Michael Rand, Kay Louise Nimmo, Ian Thompson, Christopher Hood
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Patent number: 5646081Abstract: This invention is directed to provide a non-reduced dielectric ceramic composition, which comprises a main component comprising BaTiO.sub.3, at least one rare earth metal oxide (Re.sub.2 O.sub.3) selected from the group consisting of Tb.sub.2 O.sub.3, Dy.sub.2 O.sub.3, Ho.sub.2 O.sub.3, and Er.sub.2 O.sub.3, and Co.sub.2 O.sub.3, where such constituents are contained at a predetermined formulation in the main component, an sub-component comprising BaO, MnO, MgO, and at least one compound selected from the group of NiO and Al.sub.2 O.sub.3, and an oxide glass mainly containing Li.sub.2 O--(Si.sub.x Ti.sub.1-x)O.sub.2 --M wherein M represents at least one member selected from the group consisting of Al.sub.2 O.sub.3 and ZrO.sub.2, wherein the main component, the sub-component, and the oxide glass are contained in described amounts. The composition is used as dielectric materials, such as monolithic ceramic capacitors, using base metals such as nickel as an internal electrode material.Type: GrantFiled: April 9, 1996Date of Patent: July 8, 1997Assignee: Murata Manufacturing Co., Ltd.Inventors: Toshiki Nishiyama, Yukio Hamaji
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Patent number: 5635436Abstract: A voltage-dependent nonlinear resistor or varistor ceramic composition consists essentially of (1) an oxide of the formula: {Sr.sub.(1-x-y) Ba.sub.x Ca.sub.y }.sub.z TiO.sub.3 wherein 0.3<x.ltoreq.0.9, 0.1.ltoreq.y.ltoreq.0.5, x+y.ltoreq.1, and 0.84<z<1.16, (2) 0.001 to 5.000 mol % of at least one oxide of niobium, tantalum, tungsten, manganese or R wherein R is yttrium or lanthanide, (3) 0.001 to 5.000 mol % of SiO.sub.2, and (4) 0.001 to 5.000 mol % of MgO. When the varistor voltage is controlled by changing a re-oxidizing temperature without changing the composition, a satisfactory nonlinear index .alpha. is available over a wide range of varistor voltage. The dependency of varistor voltage on heat treating temperature is reduced.Type: GrantFiled: June 13, 1996Date of Patent: June 3, 1997Assignee: TDK CorporationInventors: Masaru Fukuda, Tadashi Ogasawara, Toshio Marui, Dai Matsuoka
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Patent number: 5635435Abstract: A dielectric ceramic composition having about 97.5 to 99.95 wt % of a main component and 0.05 to 2.5 wt % of a first subcomponent, the main component having the following general formula:{100-(a+b+c+d+e)}BaTiO.sub.3 +aBi.sub.2 O.sub.3 +bNb.sub.2 O.sub.5 +cMxO+dMyO.sub.2 +eMz,wherein Mx is at least one element selected from the group consisting of Mg, Ca and Zn; My is at least one element selected from the group consisting of Ti, Sn and Zr; Mz is at least one oxide of an element selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Dy, Ho and Er; and a, b, c, d, and e are mole % and are in the following ranges: 1.0.ltoreq.a.ltoreq.6.0, 0.5.ltoreq.b.ltoreq.4.5, 0.ltoreq.c.ltoreq.4.0, 1.5.ltoreq.d.ltoreq.15.0, and 0.5.ltoreq.e.ltoreq.5.5; and the first subcomponent comprising a glass mainly containing SiO.sub.2. The composition can be subjected to firing at 1,160.degree. C.Type: GrantFiled: April 19, 1996Date of Patent: June 3, 1997Assignee: Murata Manufacturing Co., Ltd.Inventor: Masamitsu Shibata
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Patent number: 5620638Abstract: Ceramics resulting from the oxide system barium oxide-rare earth oxide-titanium oxide have been found to exhibit an isotropy with respect to electrical properties such as the temperature coefficient of frequency at the first resonant frequency, dielectric constant, and, to some extent, the loss factor, Q. Such anisotropy effects reproducibility in fabricating ceramic articles for use in the microwave region and in the performance of these articles. Isotropic ceramics from the same ternary oxide system can be made by compacting non-nucleated powders followed by the usual sintering of the green compact. Anisotropic bulk ceramic workpieces can be machined to reproducibiy afford ceramic articles with the appropriate value of the electrical property in question by measuring the components of the electrical property along the three principal axes of the workpiece, and then determining the angles between the principal axes necessary to give a resultant having the preselected value.Type: GrantFiled: May 12, 1994Date of Patent: April 15, 1997Assignee: Trans Tech, Inc.Inventors: Taki Negas, Steven Bell
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Patent number: 5612268Abstract: The present invention relates to a dielectric ceramic composition, comprising from 97.5 to 99.95% by weight of{100-(a+b+c+d)}BaTiO.sub.3 +aZnO+b(2Bi.sub.2 O.sub.3.3AO.sub.2)+cTa.sub.2 O.sub.5 +dRe.sub.2 O.sub.3as main component and from 0.05 to 2.5% by weight of glass mainly comprising SiO.sub.2, and possibly also containing from 0.01 to 0.5% by weight of at least one oxides of Cr, Mn, Fe, Co, and/or Ni. A represents Zr or Sn; Re represents at least one of La, Pr, Nd, Sm, Dy and Er; and {100-(a+b+c+d)}, a, b, c, and d represent molar percent which satisfy the following relationships:______________________________________ 0.5 .ltoreq. a .ltoreq. 4.5 0.5 .ltoreq. b .ltoreq. 4.5 0.5 .ltoreq. c .ltoreq. 4.5 0.5 .ltoreq. d .ltoreq. 5.5.Type: GrantFiled: May 22, 1995Date of Patent: March 18, 1997Assignee: Murata Manufacturing Co., Ltd.Inventors: Sakiko Iwamoto, Masamitsu Shibata, Yukio Hamaji
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Patent number: 5571767Abstract: Multi-layer ceramic capacitors are made from novel low temperature fired ceramic dielectric compositions which may have dielectric constants of over 3200 at room temperature, and which do not vary in value by more than 15 percent over a temperature range of -55.degree. C. to +125.degree. C., with the value at +25.degree. C. being the reference point. The compositions comprise a base ceramic formulation or host material, a ceramic sintering aid, and a low melting point glass formulation, each derived from metal oxides or precursors thereof. The host material is made from 97.89 to 98.19 weight percent barium titanate and from about 1.81 to 2.11 weight percent neodymium oxide, the sintering aid from Bi.sub.2 O.sub.3 .multidot.2TiO.sub.2, and the the glass formulation from 86.0 wt. % PbO, 9.0 wt. % B.sub.2 O.sub.3, 1.58 wt. % SiO.sub.2, 0.13 wt. % TiO.sub.2 and 3.29 wt. % Al.sub.2 O.sub.3. Manganese dioxide or a precursor is added in an amount of about 0.205 wt.Type: GrantFiled: August 21, 1995Date of Patent: November 5, 1996Assignee: Ferro CorporationInventors: James M. Wilson, Walter J. Symes, Jr.
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Patent number: 5556818Abstract: A substituted barium-neodymium-titanium-perovskite which has a defect structure and which has the following general composition:[A'.sub.al.sup.ml+ A".sub.a2.sup.n2+ . . . A.sup.n '.sub.an.sup.n.spsp.n.sup.+ .box-solid..sub.an+1 ] [B'.sub.b1.sup.m1+ B".sub.b2.sup.m2 + . . . B.sup.m '.sub.bm.sup.m.spsp.n.sup.+] O.sub.3,wherein the cations A'.sub.a1.sup.n1+ A".sub.a2.sup.n2+ . . . A.sup.n '.sub.an.sup.n.spsp.n.sup.+ at least comprise Ba.sup.2+, Nd.sup.3+ and, optionally, one or more cations of the group consisting of Cs.sup.1+, Rb.sup.1+, Tl.sup.1+, K.sup.1+, Pb.sup.2+, Ag.sup.1+, Sr.sup.2+, Na.sup.1+, Bi.sup.3+, La.sup.3+, Ca.sup.2+, Ce.sup.3+, Cd.sup.2+, Pr.sup.3+, Sm.sup.3+, Eu.sup.3+, Gd.sup.3+, Th.sup.4+, Tb.sup.3+, Mn.sup.2+, Li.sup.1+, Dy.sup.3+, U.sup.4+, Y.sup.3+, Fe.sup.2+, Ho.sup.3+, Ce.sup.4+, Co.sup.2+, Zn.sup.2+, Er.sup.3+, Tm.sup.3+, Yb.sup.3+, and/or Lu.sup.3+, and the cations B'.sub.b1.sup.m1+ B".sub.b2.sup.m2+ . . . B.sup.m '.sub.bm.sup.m.spsp.n.sup.+ at least comprise titanium Ti.sup.Type: GrantFiled: September 30, 1994Date of Patent: September 17, 1996Assignee: U.S. Philips CorporationInventors: Heinz Kohler, Dieter Mateika, Sietse Oostra
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Patent number: 5554571Abstract: Powder of dielectric ceramic materials is produced by preparing a main component Ba(Ti.sub.1-x-y Zr.sub.x Hf.sub.y)O.sub.3 allowing barium hydroxide, at least one titanium compound, at least one zirconium compound and at least one hafnium compound to react with one another by condensation by catalytic actions of a base selected from the group consisting of alkali and amines; preparing a complex hydroxide of at least one rare earth element and manganese by allowing at least one rare earth element compound and a manganese compound to react with a base selected from the group consisting of alkali and amines in an aqueous solution; preparing at least one carbonate of calcium and magnesium by allowing at least one compound of calcium compounds and magnesium compounds to react with carbonate ions in an aqueous solution; mixing all the precipitates, and drying and thermally treating the resultant mixture.Type: GrantFiled: October 3, 1995Date of Patent: September 10, 1996Assignee: Murata Manufacturing Co., Ltd.Inventors: Shinsei Okabe, Sakiko Iwamoto, Harunobu Sano
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Patent number: 5532197Abstract: There is disclosed a dielectric material for high frequencies comprising a composition system represented by the following formula:x(Li.sub.1/2 Nd.sub.1/2)TiO.sub.3 --yCaTiO.sub.3 --zBa(Zn.sub.1/3 Nb.sub.2/3)O.sub.3wherein0.60.ltoreq.x.ltoreq.0.80.04.ltoreq.y.ltoreq.0.38 and0.02.ltoreq.z.ltoreq.0.16.Type: GrantFiled: June 2, 1995Date of Patent: July 2, 1996Assignee: Korea Institute of Science and TechnologyInventors: Kyung Yong Kim, Wang Sup Kim, Jung Rak Yun, Kwang Ho Chang
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Patent number: 5512196Abstract: A material which possesses both capacitive and inductive properties for suppressing electromagnetic interference is provided, wherein the material is a composite of a ferroelectric material and a ferromagnetic material. The ferroelectric-ferromagnetic composite material is formulated and processed so as to retain the distinct electrical properties of the individual constituents according to the relative quantities of the constituents present in the ferroelectric-ferromagnetic composite material. As a unitary composite element, the ferroelectric-ferromagnetic composite is readily formable to provide a compact electrical filter whose filtering capability is highly suitable for suppressing electromagnetic interference from sources internal and external to an automotive environment. The sintered composite has a very low porosity; interconnectivity between the ferroelectric and ferromagnetic phases; and has no chemical reaction between the ferroelectric and ferromagnetic phases to produce a third phase.Type: GrantFiled: June 27, 1994Date of Patent: April 30, 1996Assignee: General Motors CorporationInventors: Joseph V. Mantese, Adolph L. Micheli, Dennis F. Dungan
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Patent number: 5512524Abstract: The present invention is directed to a ceramic composition comprising at least three of the four phases BaTi.sub.4 O.sub.9, Ba.sub.2 Ti.sub.9, BaZn.sub.2 Ti.sub.4 O.sub.11 and Ba.sub.3 Nb.sub.4 Ti.sub.4 O.sub.21 (i.e., the phases BT.sub.4 ss, BZ.sub.2 T.sub.9 ss BZ.sub.2 T.sub.4 and BNbT). The ceramic composition may further comprise the phase Ba.sub.3 Ta.sub.4 Ti.sub.4 O.sub.21 (BTaT). The ceramic compositions have an excellent combination of electrical characteristics including Q value at the frequencies of interest for dielectric resonators, the dielectric constant and the T.sub.f value and are well adapted for use as electrical components in equipment operating at microwave frequencies such cellular communications equipment.Type: GrantFiled: December 29, 1994Date of Patent: April 30, 1996Assignee: Trans-Tech, Inc.Inventors: Taki Negas, Glenn J. Yeager
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Patent number: 5510305Abstract: A non-reducible dielectric ceramic composition consists essentially of a main component and at least one oxide selected from the group consisting of oxides of Mn, Fe, Cr, Co and Ni. The main component has a composition of the general formula: {(Ba.sub.1-o-p-q-r Sr.sub.o Ca.sub.p R1.sub.q R2.sub.r)O.sub.1+q/2+r/2 }.sub.m (Ti.sub.1-x-y Zr.sub.x Hf.sub.y)O.sub.2, where R1 is at least one element selected from the group consisting of La, Ce, Nd, Pr and Sm, R2 is at least one element selected from the group consisting of Dy, Ho, Er, Yb and Y, and o, p, q, r, x, y and m meet the following conditions: 0<o.ltoreq.0.32, 0.ltoreq.p.ltoreq.0.20, 0<q.ltoreq.0.02, 0<r.ltoreq.0.02, 0<x.ltoreq.0.24, 0<y.ltoreq.0.16, 1.00.ltoreq.m.ltoreq.1.03, and 0<q+r.ltoreq.0.03. The content of additive is 0.02 to 2.0 moles per 100 moles of the main component when calculated in terms of respective oxides, MnO, Fe.sub.2 O.sub.3, Cr.sub.2 O.sub.3, CoO and NiO.Type: GrantFiled: June 14, 1994Date of Patent: April 23, 1996Assignee: Murata Manufacturing Co., Ltd.Inventors: Harunobu Sano, Yukio Hamaji
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Patent number: 5493262Abstract: A dielectric ceramic composition is disclosed which consists essentially of: a main ceramic composition containing barium oxide, titanium oxide, rare earth oxide and bismuth oxide as major components, which composition is represented by xBaO.yTiO.sub.2.z[(1-a)RE.sub.2 O.sub.3.aBi.sub.2 O.sub.3 ] where RE represents at least one rare earth metal, 0.10.ltoreq.x.ltoreq.0.20, 0.60.ltoreq.y.ltoreq.0.75, 0.10.ltoreq.z.ltoreq.0.25, x+y+z=1 and 0<a.ltoreq.0.3; and a glass composition composed of ZnO, B.sub.2 O.sub.3 and SiO.sub.2, which is represented by k(wt. %)ZnO.m(wt. %)B.sub.2 O.sub.3.n(wt. %)SiO.sub.2 where 30.ltoreq.k.ltoreq.85, 5.ltoreq.m.ltoreq.50, 2.ltoreq.n.ltoreq.40, k+m+n=100. The glass composition is contained in an amount of at least 0.1 part by weight, but not more than (18-62.5a) parts by weight (where 0<a.ltoreq.0.2) or not more than 5.5 parts by weight (where 0.2<a.ltoreq.0.3), per 100 parts by weight of the main ceramic composition.Type: GrantFiled: May 16, 1995Date of Patent: February 20, 1996Assignee: NGK Insulators, Ltd.Inventors: Masahiro Abe, Tsutomu Nanataki, Shinsuke Yano
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Patent number: 5488019Abstract: A dielectric ceramic composition is disclosed which consists essentially of: a main ceramic composition containing barium oxide, titanium oxide, rare earth oxide and bismuth oxide as major components, which composition is represented by xBaO.yTiO.sub.2.z[(1-a)RE.sub.2 O.sub.3.aBi.sub.2 O.sub.3 ] where RE represents at least one rare earth metal, 0.10.ltoreq.x.ltoreq.0.20, 0.60.ltoreq.y.ltoreq.0.75, 0.10.ltoreq.z.ltoreq.0.25, x+y+z=1 and 0<a.ltoreq.0.3; and a glass composition composed of ZnO, B.sub.2 O.sub.3 and SiO.sub.2, which is represented by k(wt. %)ZnO.m(wt. %)B.sub.2 0.sub.3.n(wt. %)SiO2 where 30.ltoreq.k.ltoreq.85, 5.ltoreq.m.ltoreq.50, 2.ltoreq.n.ltoreq.40, k+m+n=100. The glass composition is contained in an amount of at least 0.1 part by weight, but not more than (18-62.5a) parts by weight (where 0<a.ltoreq.0.2) or not more than 5.5 parts by weight (where 0.2<a.ltoreq.0.3), per 100 parts by weight of the main ceramic composition.Type: GrantFiled: May 31, 1994Date of Patent: January 30, 1996Assignee: NGK Insulators, Ltd.Inventors: Masahiro Abe, Tsutomu Nanataki, Shinsuke Yano
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Patent number: 5485132Abstract: A dielectric ceramic composition is disclosed which consists essentially of: a main ceramic composition containing barium oxide, titanium oxide, rare earth oxide and bismuth oxide as major components, which composition is represented by xBaO.multidot.yTiO.sub.2 .multidot.z[(1-a)RE.sub.2 O.sub.3 .multidot.aBi.sub.2 O.sub.3 ] where RE represents at least one rare earth metal, 0.10.ltoreq.x.ltoreq.0.20, 0.60.ltoreq.y.ltoreq.0.75, 0.10 .ltoreq.z.ltoreq.0.25, x+y+z=1 and 0<a.ltoreq.0.3; and a glass composition composed of ZnO, B.sub.2 O.sub.3 and SiO.sub.2, which is represented by k(wt. %)ZnO.multidot.m(wt. %)B.sub.2 O.sub.3 .multidot.n(wt. %)SiO.sub.2 where 30 .ltoreq.k.ltoreq.85, 5.ltoreq.m.ltoreq.50, 2.ltoreq.n.ltoreq.40, k+m+n=100. The glass composition is contained in an amount of at least 0.1 part by weight, but not more than (18-62.5a) parts by weight (where 0<a.ltoreq.0.2) or not more than 5.5 parts by weight (where 0.2<a<0.3), per 100 parts by weight of the main ceramic composition.Type: GrantFiled: May 16, 1995Date of Patent: January 16, 1996Assignee: NGK Insulators, Ltd.Inventors: Masahiro Abe, Tsutomu Nanataki, Shinsuke Yano
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Patent number: 5479140Abstract: A dielectric ceramic composition is disclosed which consists essentially of: a main ceramic composition containing barium oxide, titanium oxide, rare earth oxide and bismuth oxide as major components, which composition is represented by xBaO.multidot.yTiO.sub.2 .multidot.z[(1-a)RE.sub.2 O.sub.3 .multidot.aBi.sub.2 O.sub.3 ] where RE represents at least one rare earth metal, 0.10.ltoreq.x.ltoreq.0.20, 0.60.ltoreq.y.ltoreq.0.75, 0.10 .ltoreq.z.ltoreq.0.25, x+y+z=1 and 0<a.ltoreq.0.3; and a glass composition composed of ZnO, B.sub.2 O.sub.3 and SiO.sub.2, which is represented by k(wt. %)ZnO.multidot.m(wt. %)B.sub.2 O.sub.3 .multidot.n(wt. %)SiO2 where 30 .ltoreq.k.ltoreq.85, 5.ltoreq.m.ltoreq.50, 2.ltoreq.n.ltoreq.40, k+m+n=100. The glass composition is contained in an amount of at least 0.1 part by weight, but not more than (18-62.5a) parts by weight (where 0<a.ltoreq.0.2) or not more than 5.5 parts by weight (where 0.2<a.ltoreq.0.3), per 100 parts by weight of the main ceramic composition.Type: GrantFiled: May 16, 1995Date of Patent: December 26, 1995Assignee: NGK Insulators, Ltd.Inventors: Masahiro Abe, Tsutomu Nanataki, Shinsuke Yano
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Patent number: 5453262Abstract: A continuous process for making a crystalline ceramic powder having a perovskite structure, ABO.sub.3, comprising:a. preparing a first acidic aqueous solution containing one or more elements that are insoluble precursor elements capable of forming the perovskite structure;b. preparing a second basic solution containing a sufficient concentration of hydroxide to precipitate the elements in step (a);c. mixing the first acidic solution with the second basic solution to precipitate a substantially pure mixture of hydroxides;d. washing the precipitate to remove hydroxide and salt impurities;e. forming a slurry of oxides or hydroxides of one or more of the elements that are soluble precursor elements capable of forming in the perovskite structure, and heating the slurry to a temperature sufficient to dissolve the soluble oxides or hydroxides of the soluble precursor elements;f. redispersing the washed precipitate and heating to the temperature of the soluble oxides or hydroxides of step (e);g.Type: GrantFiled: June 10, 1992Date of Patent: September 26, 1995Assignee: Battelle Memorial InstituteInventors: William J. Dawson, Scott L. Swartz
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Patent number: 5453409Abstract: A miniaturized ceramic capacitor having excellent electric characteristics and substantial capacity can be obtained by firing under a non-oxidative atmosphere at a temperature of up to 1200.degree. C. A dielectric layer of this ceramic capacitor consists of a basic component of 100 parts by weight and an additional component of 0.2 to 5 parts by weight. The basic component consists essentially of a material represented by the following formula:{(Ba.sub.1-w-x Ca.sub.w Mg.sub.x)O}k(Ti.sub.1-y-z Zr.sub.y R.sub.z)O.sub.2-z/2The additional component consists essentially of Li.sub.2 O--SiO.sub.2 --MO, B.sub.2 O.sub.3 --SiO.sub.2 --MO or B.sub.2 O.sub.3 --SiO.sub.2 --Li.sub.2 O.Type: GrantFiled: June 5, 1992Date of Patent: September 26, 1995Assignee: Taiyo Yuden Co., Ltd.Inventors: Hiroshi Kishi, Hisamitsu Shizuno, Shinya Kusumi, Hiroshi Saito
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Patent number: 5453908Abstract: A semiconductor device and process for making the same are disclosed which incorporate a relatively large percentage of holmium dopant (0.5 to 5%) into a BST dielectric film 24 with small grain size (e.g. 10 nm to 50 nm). Dielectric film 24 is preferably disposed between electrodes 18 and 26 (which preferably have a Pt layer contacting the BST) to form a capacitive structure with a relatively high dielectric constant and relatively low leakage current. Apparently, properties of the thin film deposition and small grain size, including temperatures well below bulk BST sintering temperatures, allow the film to support markedly higher defect concentrations without holmium precipitation than are observed for bulk BST. For holmium doping levels generally between 0.5 and 5% (compensated with titanium and/or manganese), better than 50% improvement in dielectric constant and two to six orders of magnitude reduction in leakage current (compared to undoped BST) have been observed for such films.Type: GrantFiled: September 30, 1994Date of Patent: September 26, 1995Assignee: Texas Instruments IncorporatedInventors: Robert Tsu, Bernard M. Kulwicki
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Patent number: 5432135Abstract: A dielectric ceramic composition for high frequency-use comprising a composition (A) containing at least Ba, Mg and W as metal elements represented by a composition formula expressed in a mole ratio of these metal elements, xBaO.yMgO.zWO.sub.3, in which x, y and z satisfy the following relation40.ltoreq.x.ltoreq.60,13.ltoreq.y.ltoreq.40,20.ltoreq.z.ltoreq.30, andx+y+z=100,and at least one element (B) selected from Group 3a elements and Group 4a elements in the periodic table, Sn, Mn and Ca. A ceramic molded product composed of this composition has a high dielectric constant and a high Q value in a high frequency region of at least 10 GHz but also has a temperature coefficient (.tau.f) of a resonance frequency which is not shifted too much to a negative side and has a suitable value. Accordingly, the composition may be preferably used as a resonator and a dielectric substrate material for MIC in a high frequency region of a microwave or a millimeter wave.Type: GrantFiled: December 16, 1993Date of Patent: July 11, 1995Assignee: Kyocera CorporationInventors: Seiichi Hirahara, Nobuyoshi Fujikawa, Tsuguo Koyasu, Sumie Koyasu
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Patent number: 5419844Abstract: Disclosed herein are piezoelectric ceramics composed of lead titanate zirconate, which is expressed in PbZr.sub.1-z Ti.sub.z O.sub.3, where z=0.45 to 0.54, with 0.1 to 8 mole percent of the Pb atoms being replaced with at least one element selected from a group of Ca, Sr and Ba, and containing Mn in a range of 0.005 to 0.9 percent by weight of the whole in terms of MnO.sub.2.Type: GrantFiled: June 23, 1993Date of Patent: May 30, 1995Assignee: Murata Manufacturing Co., Ltd.Inventors: Kiyoshi Hase, Akira Ando, Yasunobu Yoneda, Toshihiko Kittaka, deceased
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Patent number: 5403788Abstract: A dielectric ceramic composite material comprising a dielectric ceramics and a glass having a softening temperature lower than the sintering temperature of the dielectric ceramics, wherein said particles of the dielectric ceramics are randomly dispersed in a matrix of the glass. This composite material can be formed by molding a mixture of the dielectric ceramics powder and glass powder at first, and by firing this mold (including a film thereof) at the softening temperature of the glass or higher. The obtained dielectric ceramics composite material can be extensively utilized as various ceramic functional elements or electronic components incorporated in various piezoelectric, pyroelectric, ferroelectric memory, actuator elements and many others.Type: GrantFiled: April 21, 1994Date of Patent: April 4, 1995Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masamitsu Nishida, Koichi Kugimiya
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Patent number: 5403797Abstract: To provide a non-reducing dielectric ceramic composition for multilayer ceramic capacitor, in which decrease of specific resistance and shortening of life time do not occur due to reduction of dielectric ceramic composition even when it is fired in neutral or reducing atmosphere and capacitance does not vary extensively due to temperature change, the non-reducing dielectric ceramic composition according to the present invention comprises 86.32 to 97.64 mols of BaTiO.sub.3, 0.01 to 10.00 mols of Y.sub.2 O.sub.3, 0.01 to 10.00 mols of MgO, and 0.001 to 0.200 mol of V.sub.2 O.sub.5. An additive containing 0.01 to 1.0 mol % of at least one or more of MnO, Cr.sub.2 O.sub.3, or Co.sub.2 O.sub.3, and further, an additive containing 0.5 to 10.0 mol % of {Ba.sub.A, Ca.sub.(1-A) }SiO.sub.3 (where 0.ltoreq.A.ltoreq.1) may be added.Type: GrantFiled: January 21, 1994Date of Patent: April 4, 1995Assignee: TDK CorporationInventors: Osamu Ohtani, Wataru Takahara
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Patent number: 5397753Abstract: A nonreducible dielectric ceramic composition consists essentially of: a primary component consisting essentially of 92.0 to 99.4 mol % of BaTiO.sub.3, 0.3 to 4.0 mol % of at least one of rare earth element, expressed by the general formula: Re.sub.2 O.sub.3, where Re is at least one rare earth element selected from the group consisting of Tb, Dy, Ho and Er, and 0.3 to 4.0 mol % of Co.sub.2 O.sub.3 ; a secondary component consisting essentially of BaO, MnO, MgO, and BaZrO.sub.3, the content of the secondary component being, per 100 moles of the primary component, 0.2 to 4.0 moles for BaO, 0.2 to 3.0 moles for MnO, 0.5 to 5 moles for MgO, and 0.5 to 4.0 moles for BaZrO.sub.3 ; and a vitreous component of a BaO--SrO--Li.sub.2 O--SiO.sub.2 system, the content of the vitreous component being 0.5 to 2.5 parts by weight per 100 parts by weight of the sum of the primary and secondary components.Type: GrantFiled: January 6, 1994Date of Patent: March 14, 1995Assignee: Murata Manufacturing Co., Ltd.Inventors: Toshiki Nishiyama, Yukio Hamaji
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Patent number: 5378663Abstract: A dielectric ceramic composition is disclosed which includes: a main ceramic composition of barium oxide and titanium oxide, or barium oxide, titanium oxide and at least one of strontium oxide, calcium oxide, zirconia and zinc oxide, which composition is represented by (1-a-b)BaO.multidot.aSrO.multidot.bCaO.multidot.x[(1-c)TiO.sub.2 .multidot.cZrO.sub.2 ].multidot.yZnO, where 3.1.ltoreq.x .ltoreq.5.4, 0.ltoreq.y.ltoreq.2.9, 0.ltoreq.a+b.ltoreq.0.4, 0.ltoreq.c.ltoreq.0.2; and a secondary component at least a part of which consists of a B.sub.2 O.sub.3 material or a glass material containing B.sub.2 O.sub.3 as one of glass components, the secondary component being added to the main ceramic composition, in an amount of 0.1-7.5 parts by weight of B.sub.2 O.sub.3 per 100 parts by weight of the main ceramic composition.Type: GrantFiled: March 2, 1994Date of Patent: January 3, 1995Assignee: NGK Insulators, Ltd.Inventors: Masahiro Abe, Tatsumi Sugiura, Tsutomu Nanataki, Shinsuke Yano
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Patent number: 5378382Abstract: The present invention relates to a piezoelectric ceramic composition for actuator which is a composition comprising a basic composition containing lead, lanthanum, alkali earth metals, zirconium, titanium and oxygen in the formulation represented by the following general formula (I): ##EQU1## where A represents one or more element(s) selected from the group consisting of Ba, Ca and Sr; 0<x.ltoreq.0.07; 0.40.ltoreq.y.ltoreq.0.65; and 0<m.ltoreq.0.15, wherein the ceramic composition containing, relative to the basic composition, one or more element(s) selected from the group consisting of iron, aluminum, manganese, indium and tellurium in an amount of 0.02 to 0.3% by weight in terms of Fe.sub.2 O.sub.3 or Al.sub.2 O.sub.3, 0.02 to 0.2% by weight in terms of MnO.sub.2 and 0.02 to 0.5% by weight in terms of In.sub.2 O.sub.3 or TeO.sub.2.Type: GrantFiled: December 9, 1993Date of Patent: January 3, 1995Assignee: Mitsubishi Kasei CorporationInventors: Tetsuhiko Nishimura, Yukio Chida, Takahiro Choda
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Patent number: 5369068Abstract: Disclosed is a bismuth layer compound expressed by a chemical formula, (M1.sub.1-2x M2.sub.x Bi.sub.4+x)Ti.sub.4 O.sub.15, wherein "M1" is alkaline earth metal including Sr at least, "M2" is alkali metal, and "x" falls in a range, 0.06.ltoreq.x.ltoreq.0.44. "M1" can be replaced by Pb or combinations of Pb and alkaline earth metal. The bismuth layer compound exhibits a less fluctuating sensitivity with respect to temperature variations. The bismuth layer compound can further include Mn in a form of MnO in an amount of from 0.02 to 0.25% by weight, and thereby it exhibits not only an upgraded sensitivity but also it does not exhibits a hysteresis in a force-electric charge output diagram.Type: GrantFiled: July 28, 1993Date of Patent: November 29, 1994Assignee: Toyota Jidosha Kabushiki KaishaInventor: Kazuhide Kaneko
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Patent number: 5362693Abstract: The present invention provides ceramic compositions for preparing multi-layer capacitors (MLCs) having high dielectric constants between about 3000 and 4700 and stable temperature coefficients (TC) prepared from high purity barium titanate, niobium pentoxide, and cobalt oxide.Type: GrantFiled: November 12, 1993Date of Patent: November 8, 1994Assignee: Tam Ceramics, Inc.Inventors: Mike S. H. Chu, Susan E. Corah
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Patent number: 5361187Abstract: Ceramic dielectric compositions for manufacturing multilayer ceramic capacitors (MLCC's) having very high dielectric constants between about 8,000-19,000 and meeting the Z5U and Y5V EIA (Electronic Industries Association) specifications for temperature coefficient of capacitance, are prepared from barium titanate host materials based upon the formulation (Ba.sub.1-x Ca.sub.x) (Ti.sub.1-y-z Sn.sub.y Zr.sub.z)O.sub.3, and doped with small amounts of niobium, manganese, lanthanum, zirconium and yttrium oxides to alter the dielectric spectrum so as to meet desired EIA specifications.Type: GrantFiled: March 11, 1993Date of Patent: November 1, 1994Assignee: Ferro CorporationInventor: Thallam T. Srinivasan
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Patent number: 5350721Abstract: A dielectric ceramic composition is disclosed which consists essentially of: a main ceramic composition containing barium oxide, titanium oxide, rare earth oxide and bismuth oxide as major components, which composition is represented by xBaO.yTiO.sub.2.z[(1-a)RE.sub.2 O.sub.3.aBi.sub.2 O.sub.3 ] where RE represents at least one rare earth metal, 0.10.ltoreq.x.ltoreq.0.20, 0.60.ltoreq.y.ltoreq.0.75, 0.10 .ltoreq.z.ltoreq.0.25, x+y+z=1 and 0<a .ltoreq.0.3; and a glass composition composed of ZnO, B.sub.2 O.sub.3 and SiO.sub.2, which is represented by k(wt. %)ZnO.m(wt. %)B.sub.2 O.sub.3 .n(wt. %)SiO2 where 30 .ltoreq.k.ltoreq.85, 5.ltoreq.m.ltoreq.50, 2.ltoreq.n.ltoreq.40, k+m+n=100. The glass composition is contained in an amount of at least 0.1 part by weight, but not more than (18-62.5a) parts by weight (where 0<a.ltoreq.0.2) or not more than 5.5 parts by weight (where 0.2<a.ltoreq.0.3), per 100 parts by weight of the main ceramic composition.Type: GrantFiled: January 14, 1994Date of Patent: September 27, 1994Assignee: NGK Insulators, Ltd.Inventors: Masahiro Abe, Tsutomu Nanataki, Shinsuke Yano
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Patent number: 5322828Abstract: A non-reducible dielectric ceramic composition consists essentially of a main component consisting essentially of oxides of BaO, CaO, MgO, TiO.sub.2, ZrO.sub.2 and Nb.sub.2 O.sub.5 and having a composition expressd by the general formula:{(Ba.sub.1-x-y Ca.sub.x Mg.sub.y)O}.sub.m (Ti.sub.1-o-p Zr.sub.o Nb.sub.p)O.sub.2+p/2wherein 0<x.ltoreq.0.20, 0<y.ltoreq.0.05, 0<o.ltoreq.0.25, 0.0005.ltoreq.p .ltoreq.0.023, and 1.000.ltoreq.m.ltoreq.1.03; at least one primary additive selected from the group consisting of oxides of Mn, Fe, Cr, Co and Ni; and at least one secondary additive selected from the group consisting of SiO.sub.2 and ZnO. The primary additives contained in an mount of 0.02 to 2.0 moles per 100 moles of the main component in terms of respective oxides, MnO.sub.2, Fe.sub.2 O.sub.3, Cr.sub.2 O.sub.3, CoO and NiO, while the secondary additive is contained in an amount of 0.1 to 2.0 moles per 100 moles of the main component.Type: GrantFiled: October 19, 1993Date of Patent: June 21, 1994Assignee: Murata Manufacturing Co., Ltd.Inventors: Harunobu Sano, Yukio Hamaji, Kunisaburo Tomono
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Patent number: 5314651Abstract: An improved pyroelectric material comprises a polycrystalline material doped with at least one donor element such that the polycrystalline material has a grain size less than 10 .mu.m (or 5 .mu.m) and a Figure of Merit greater than 90 nC/(cm.sup.2.K). In the preferred embodiments the polycrystalline material is barium strontium titanate or calcium-substituted barium strontium titanate. The donor element may be Nb, Ta, Bi, Sb, Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er or a combination thereof. The material may additionally be doped with an acceptor such as Co, Cu, Fe, Mn, Ru, Al, Ga, Mg, Sc, K, Na, U, In, Mg, Ni, Yb or a combination thereof to control the resistivity. Other structures and methods are also disclosed.Type: GrantFiled: May 29, 1992Date of Patent: May 24, 1994Assignee: Texas Instruments IncorporatedInventor: Bernard M. Kulwicki
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Patent number: 5310710Abstract: A dielectric ceramic composition which comprises a composition represented by xBaO.yNd.sub.2 O.sub.3.zTiO.sub.2 (where 8.5.ltoreq.x.ltoreq.20, 5.ltoreq.y.ltoreq.23, 62.ltoreq.z.ltoreq.85, and x+y+z=100), Y.sub.2 O.sub.3 in an amount not more than 15 wt % of the amount of said composition, and Al.sub.2 O.sub.3 in an amount not more than 2 wt % of the total amount of the principal components BaO, Nd.sub.2 O.sub.3, TiO.sub.2, and Y.sub.2 O.sub.3. And a relative permittivity .epsilon.r of the dielectric ceramic is not less than 59, its dielectric loss (tan .delta.) is 3.times.10.sup.-4 .about.8.times.10.sup.-4 (2.7 GHz), and its temperature coefficient of resonant frequency .tau.f may be -30.about.+10 ppm/.degree.C. This microwave ceramic dielectric will be used for dielectric resonators in the microwave frequency region, microwave IC substrates, and impedance matching of microwave circuits.Type: GrantFiled: April 6, 1992Date of Patent: May 10, 1994Assignee: NGK Spark Plug Company, Ltd.Inventors: Masanori Takase, Hirofumi Ozeki
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Patent number: 5310709Abstract: A nonreducible dielectric ceramic composition of a system, (A.sub.1-x R.sub.x).sub.y BO.sub.3, is produced using using at least one compound selected from the group consisting of water-soluble inorganic compounds and organic solvent-soluble organometallic compounds of rare earth element R together with oxides and/or carbonates of elements A and B.Type: GrantFiled: February 14, 1992Date of Patent: May 10, 1994Assignee: Murata Manufacturing Co., Ltd.Inventors: Nobuyuki Wada, Yoshiaki Kohno
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Patent number: 5304521Abstract: A dielectric ceramic composition is disclosed which consists essentially of: a main ceramic composition containing barium oxide, titanium oxide, rare earth oxide and bismuth oxide as major components, which composition is represented by xBaO.yTiO.sub.2.z[(1-a)RE.sub.2 O.sub.3.aBi.sub.2 O.sub.3 ] where RE represents at least one rare earth metal, 0.10.ltoreq.x.ltoreq.0.20, 0.60.ltoreq.y.ltoreq.0.75, 0.10.ltoreq.z.ltoreq.0.25, x+y+z=1 and 0<a.ltoreq.0.3; and a glass composition composed of ZnO, B.sub.2 O.sub.3 and SiO.sub.2, which is represented by k(wt. %)ZnO.m(wt. %)B.sub.2 O.sub.3 .n(wt. %)SiO2 where 30.ltoreq.k.ltoreq.85, 5.ltoreq.m.ltoreq.50, 2.ltoreq.n.ltoreq.40, k+m+n=100. The glass composition is contained in an amount of at least 0.1 part by weight, but not more than (18-62.5a) parts by weight (where 0<a.ltoreq.0.2) or not more than 5.5 parts by weight (where 0.2<a.ltoreq.0.3), per 100 parts by weight of the main ceramic composition.Type: GrantFiled: August 4, 1993Date of Patent: April 19, 1994Assignee: NGK Insulators, Ltd.Inventors: Masahiro Abe, Tsutomu Nanataki, Shinsuke Yano
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Patent number: 5296424Abstract: A system of dielectric ceramic compositions suitable for various microwave applications. The system comprises a plurality of stoichiometrically-related compositions, each composition having its own particular set of dielectric properties and consisting essentially of a sintered mixture represented by the general formula:BaTi.sub.4-w M.sub.w O.sub.9 --xZn.sub.2 TiO.sub.4 --yBaO--zTa.sub.2 O.sub.5wherein M is at least one type of metal and 0.0.ltoreq.w.ltoreq.about 0.05 and wherein x, y, and z are molar fractions of respective components with values within the following respective ranges: 0.0.ltoreq.x.ltoreq.about 0.45; about 0.01.ltoreq.y.ltoreq.about 0.20; and 0.0.ltoreq.z.ltoreq.about 0.10.Type: GrantFiled: April 22, 1992Date of Patent: March 22, 1994Assignee: GTE Control Devices IncorporatedInventors: Da Y. Wang, Burton W. MacAllister, Daniel T. Kennedy, Joanne Browne, Kazumasa Umeya
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Patent number: 5296426Abstract: A composition for forming a densified ceramic dielectric body, the composition consisting essentially of (a) about 96.0-98.0 wt. % barium titanate having an average particle size of 0.5-1.25 microns; (b) 0.3-1.2 wt. % niobium oxide or precursor thereof; (c) 0.4-1.2 wt. % zinc oxide or precursor thereof; (d) 0.1-1.2 wt. % neodymium oxide or precursor thereof; (e) 0.15-0.75 wt. % boron oxide or precursor thereof; and (f)0-0.1 wt. % manganese oxide or precursor thereof. This composition can be used to form the dielectric layers in multilayer electrical devices such as circuits and capacitors.Type: GrantFiled: July 20, 1992Date of Patent: March 22, 1994Assignee: E. I. Du Pont de Nemours and CompanyInventor: Ian Burn
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Patent number: 5296425Abstract: A dielectric ceramic composition consists essentially of 100 mole parts of a major ingredient expressed by the formula,(Ba.sub.1-x Ca.sub.x)(Ti.sub.1-y Zr.sub.y)O.sub.3,where x is a numeral in the range of 0.01 to 0.10, and y is a numeral in the range of 0.10 to 0.24. To this major ingredient there are added from 0.10 to 2.0 mole parts of an erbium compound, and from 0.03 to 0.30 mole part of a manganese compound. Optionally, for the provision of low temperature sinterable ceramic compositions, there are also added from 0.03 to 0.40 mole part of a zinc compound and from 0.01 to 0.20 mole part of a silicon compound. Monolithic, solid dielectric capacitors are also disclosed which have ceramic bodies formulated from the above compositions.Type: GrantFiled: July 28, 1993Date of Patent: March 22, 1994Assignee: Taiyo Yuden Co., Ltd.Inventors: Hirokazu Chazono, Yasuyuki Inomata, Kazuyuki Shibuya, Katsuyuki Horie
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Method of producing low temperature firing dielectric ceramic composition containing B.sub.2 O.sub.3
Patent number: 5292694Abstract: A method of producing a dielectric ceramic composition is disclosed which includes the steps of: preparing a main ceramic composition comprising BaO, TiO, and RE.sub.2 O.sub.3 (where RE represents at least one rare earth metal) as major components; calcining a mixture of starting materials which give the main ceramic composition, at a temperature of 1050.degree. C. or higher, to provide a calcined mixture; finely pulverizing the calcined mixture to provide a calcined ceramic powder having an average grain size of not larger than 0.8 .mu.m; and adding, as at least a part of a secondary component, a B.sub.2 O.sub.3 powder or a glass powder containing B.sub.2 O.sub.3, to the main ceramic composition. Also disclosed are a dielectric resonator and dielectric filter using such a dielectric ceramic composition as produced according to the above method, and a method of producing such a dielectric resonator or filter.Type: GrantFiled: September 25, 1992Date of Patent: March 8, 1994Assignee: NGK Insulators, Ltd.Inventors: Masahiro Abe, Tsutomu Nanataki, Shinsuke Yano -
Patent number: 5290740Abstract: A dielectric ceramic composition is disclosed which includes: a main ceramic composition of barium oxide and titanium oxide, or barium oxide, titanium oxide and at least one of strontium oxide, calcium oxide, zirconia and zinc oxide, which composition is represented by (1-a-b)BaO.aSrO.bCaO.x[(1-c)TiO.sub.2.cZrO.sub.2 ].yZnO, where 3.1.ltoreq.x.ltoreq.5.4, 0.ltoreq.y.ltoreq.2.9, 0.ltoreq.a+b.ltoreq.0.4, 0.ltoreq.c.ltoreq.0.2; and a secondary component at least a part of which consists of a B.sub.2 O.sub.3 material or a glass material containing as one of glass components, the secondary component being added to the main ceramic composition, in an amount of 0.1-7.5 parts by weight of B.sub.2 O.sub.3 per 100 parts by weight of the main ceramic composition.Type: GrantFiled: November 3, 1992Date of Patent: March 1, 1994Assignee: NGK Insulators, Ltd.Inventors: Masahiro Abe, Tatsumi Sugiura, Tsutomu Nanataki, Shinsuke Yano
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Patent number: 5284810Abstract: When the ratio of a dielectric ceramic composition is expressed as xPb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3 --yPb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 --zPb(Sm.sub.1/2 Nb.sub.1/2) O.sub.3, the values x, y and z are set to lie inside the coordinates A, B, C, D, E (but excluding the segment AE) in a triangular diagram of FIG. 1, and wherein BaTiO.sub.3 is added thereto at a ratio of smaller 10 than 10 mol % and MnO.sub.2 is further added thereto at a ratio of from 0.01 to 0.6% by weight. There is obtained a dielectric ceramic which has a high dielectric constant, a low dissipation factor, a temperature more stable of dielectric constant, a good ceramic density and ceramic strength and that can be baked at a low temperature, and that are usable to MLCCS using Ag-Pd electrodes.Type: GrantFiled: June 26, 1992Date of Patent: February 8, 1994Assignee: Kyocera CorporationInventors: Nobuo Yokoe, Hitoshi Ohkoda, Hiroshi Kikuyama
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Patent number: 5268342Abstract: A nonreducing dielectric ceramic composition that includes BaTi0.sub.3 as a main component, the BaTi0.sub.3 containing alkali metal oxides in an amount more than 0.04 weight % as impurities. One or more of the following rare earth metal oxides (Re.sub.2 O.sub.3): Tb.sub.2 O.sub.3, Dy.sub.2 O.sub.3, Ho.sub.2 O.sub.3 and Er.sub.2 O.sub.3 ; and Co.sub.2 O.sub.3 in the following ratios: BaTiO.sub.3 is 92.0-00.4 mol %; Re.sub.2 O.sub.3 is 0.3-4.0 mol %; and Co.sub.2 O.sub.3 is 0.3-4.0 mol %; the composition also includes the following subcomponents: 0.2-4.0 mol % BaO; 0.2-3.0 mol % of MnO; and 0.5-5.0 mol % of MgO. The composition may include 0.5-2.5 weight parts of oxide glass containing BaO-SrO-Li.sub.2 O-SiO.sub.2 incorporated with 100 weight parts for the above composition. The composition may also include 0.5-4.0 mol % CaTiO.sub.3, 0.5-3.5 mol % CaZrO.sub.3 or one or both of NiO and Al.sub.2 O.sub.3 in an amount 0.3-3.0 mol %. Further, 0.5-2.5 weight parts of oxide glass containing BaO-SrO-Li.sub.2 O-SiO.sub.Type: GrantFiled: June 25, 1992Date of Patent: December 7, 1993Assignee: Murata Manufacturing Co., Ltd.Inventors: Toshiki Nishiyama, Yukio Hamaji, Yukio Sakabe
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Patent number: 5264403Abstract: A dielectric ceramic composition is disclosed which consists essentially of: a main ceramic composition containing barium oxide, titanium oxide, rare earth oxide and bismuth oxide as major components, which composition is represented by xBaO.multidot.yTiO.sub.2 .multidot.Z[(1-a)RE.sub.2 O.sub.3 .multidot.aBi.sub.2 O.sub.3 ] where RE represents at least one rare earth metal, 0.10.ltoreq.x.ltoreq.0.20, 0.60.ltoreq.y.ltoreq.0.75, 0.10 .ltoreq.z.ltoreq.0.25, x+y+z=1 and 0<a.ltoreq.0.3; and a glass composition composed of ZnO, B.sub.2 O.sub.3 and SiO.sub.2, which is represented by k(wt.%)ZnO.multidot.m(wt.%)B.sub.2 O.sub.3 .multidot.n(wt.%)SiO.sub.2 where 30 .ltoreq.k.ltoreq.85, 5.ltoreq.m.ltoreq.50, 2.ltoreq.n.ltoreq.40, k+m+n=100. The glass composition is contained in an amount of at least 0.1 part by weight, but not more than (18-62.5a) parts by weight (where 0<a.ltoreq.0.2) or not more than 5.5 parts by weight (where 0.2<a.ltoreq.0.3), per 100 parts by weight of the main ceramic composition.Type: GrantFiled: September 23, 1992Date of Patent: November 23, 1993Assignee: NGK Insulators, Ltd.Inventors: Masahiro Abe, Tsutomu Nanataki, Shinsuke Yano
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Patent number: 5264402Abstract: The present invention is directed to non-reducible dielectric composition consisting essentially of a main composition composed of a modified barium titanate system and additives (A) and (B) incorporated therein, said main composition consisting essentially of oxides of Ba, Ca, Ti, Zr, and Nb and having a composition represented by general formula:{(Ba.sub.1-x Ca.sub.x)O}.sub.m (Ti.sub.1-o-p Zr.sub.o Nb.sub.p)O.sub.2+p/2'wherein x, o, p and m satisfy the relationships of, ##EQU1## said additive (A) being composed at least one oxides selected from the group consisting of oxides of Mn, Fe, Cr, Co, and Ni, said additive (A) being incorporated into said main composition in an amount of 0.02 to 2.0 moles per 100 moles of said main composition in terms of respective oxides, MnO.sub.2, FeO.sub.3, Cr.sub.2 O.sub.3, CoO, and NiO, said additive (B) consisting of SiO.sub.2 and/or ZnO and incorporated into said main composition in an amount of 0.1 to 2.0 moles per 100 moles of said main composition.Type: GrantFiled: May 3, 1993Date of Patent: November 23, 1993Assignee: Murata Manufacturing Co., Ltd.Inventors: Harunobu Sano, Yukio Hamaji, Kunisaburo Tomono
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Patent number: 5258338Abstract: Disc and monolithic (multilayer) ceramic capacitors having a fine grained barium titanate body exhibit a high dielectric constant and a smooth (X7R) temperature coefficient of capacitance. The start ceramic materials for making such capacitors are predominantly spherical barium titanate powder particles of average particle size less than 0.7 micron and of narrow particle size distribution. The barium titanate is mixed with around 2 weight percent of a the cadmium silicate flux, 3Cd.SiO.sub.2, serving as a reactivity and sintering promoting agent; and about one weight percent of a reactivity and sintering inhibitor agent, Nb.sub.2 O.sub.5. After preparing a green body of this mixture, the body is sintered at about 1100.degree. C.Type: GrantFiled: July 27, 1992Date of Patent: November 2, 1993Assignee: MRA LaboratoriesInventor: Galeb H. Maher