US 5,184,277 AGranted

Ceramic capacitor and method for fabricating the same

AssigneeTaiyo Yuden Kabusikigaisha

InventorsHisamitsu Shizuno, Hirosi Kisi, Hirosi Saito, Makoto Fujii

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Abstract

A ceramic capacitor having excellent electric characteristics includes internal electrodes comprising a base metal such as Ni, and a method for fabricating the capacitor includes the step of firing under a non-oxidation atmosphere. A dielectric layer of the ceramic capacitor comprises a basic and additional components. The basic components comprises a material represented by the following formula: (1-.alpha.) {(Ba.sub.k-x-z M.sub.x L.sub.z)O.sub.k (Ti.sub.1-y R.sub.y)O.sub.2-y/2 }+.alpha.BaZrO.sub.3 where, M is Mg and/or Zn, L is Ca and/or Sr, R is a rare earth element, and .alpha., k, x, z and y are nuermals fulfilling the conditions of 0.005.ltoreq..alpha..ltoreq.0.04, 1.00.ltoreq.k.ltoreq.k.ltoreq.1.05, 0<x<0.10, 0<z.ltoreq.0.05, 0.01.ltoreq.x+z.ltoreq.0.10, and 0<y.ltoreq.0.04. The additional component comprises Li.sub.2 O (or B.sub.2 O.sub.3), SiO.sub.2 and MO (MO is at least one metal oxide selected from the group consisting of BaO, SrO, CaO, MgO and ZnO).

Claims4

Dependent claims

A ceramic capacitor, comprising:

at least one dielectric ceramic layer of a dielectric ceramic composition and at least two internal electrodes sandwiching said dielectric ceramic composition;
said dielectric ceramic composition comprising a fired mixture of a basic component of 100 weight portions and an additional compenent in the range of 0.2 to 5 weight portions;
said basic component comprising a material represent by the following formula:
(1-.alpha.){(Ba.sub.k-x-z M.sub.x L.sub.z)O.sub.k (Ti.sub.1-y R.sub.y)O.sub.2-y/2 }+.alpha.BaZrO.sub.3
where, M is Mg and/or Zn, L is Ca and/or Sr, R is one or more metal elements selected from the group consisting of Sc, Y, Gd, Dy, Ho, Er, Yb, Tb, Tm and Lu;
and .alpha., k, x, z and y are numerals fulfilling the following conditions:
0.005.ltoreq..alpha..ltoreq.0.04
1.00.ltoreq.k.ltoreq.1.05
0<x<0.10
0<z<0.05
0.01.ltoreq.x+z.ltoreq.0.10
0<y.ltoreq.0.04;
said additional component comprising Li.sub.2 O, SiO.sub.2 and MO (wherein said MO is at least one metal oxide selected from the group consisting of BaO, SrO, CaO, MgO and ZnO);
and
at least one metal oxide selected from a group consisting of BaO, SrO, CaO, MgO and ZnO);
and
a ratio among amounts of Li.sub.2 O, SiO.sub.2 and MO in said additional component is within an area in a ternary system diagram of mol % having five vertexes of first to fifth vertexes, wherein:
said first vertex A represents a condition in which amounts of Li.sub.2 O is 1 mol %, SiO.sub.2 is 80 mol % and MO is 19 mol %;
said second vertex B represents a condition in which amounts of Li.sub.2 O is 1 mol %, SiO.sub.2 is 39 mol % and MO is 60 mol %;
said third vertex C represents a condition in which amounts of Li.sub.2 O is 30 mol %, SiO.sub.2 is 30 mol % and MO is 40 mol %;
said fourth vertex D represents a condition in which amounts of Li.sub.2 O is 50 mol %, SiO.sub.2 is 50 mol % and MO is 0 mol %;
and
said fifth vertex E represents a condition in which amounts of Li.sub.2 O is 20 mol %, SiO.sub.2 is 80 mol % and MO is 0 mol %.

20 more elements

A ceramic capacitor, comprising:

at least one dielectric ceramic layer comprising a dielectric ceramic composition and at least two internal electrodes sandwiching said dielectric ceramic composition;
said dielectric ceramic composition comprising a fired mixture of a basic component of 100 weight portions and and additional component in the range of 0.2 to 5 weight portions:
said basic component comprising a material represented by the following formula:
(1-.alpha.){(Ba.sub.k-x-z M.sub.x L.sub.z)O.sub.k (Ti.sub.1-y R.sub.y)O.sub.2-y/2 }+.alpha.BaZrO.sub.3
where, M is Mg and/or Zn, L is Ca and/or Sr, R is one or more metal elements selected from the group consisting of Sc, Y, Gd, Dy, Ho, Er, Yb, Tb, Tm and Lu;
and .alpha., k, x, z and y are numerals fulfilling the following conditions:
0.005.ltoreq..alpha..ltoreq.0.04
1.00.ltoreq.k.ltoreq.1.05
0<x<0.10
0<z.ltoreq.0.05
0.01.ltoreq.x+z.ltoreq.0.10
0<y.ltoreq.0.04;
said additional component comprising B.sub.2 O.sub.3, SiO.sub.2 and MO (wherein said MO is at least one metal oxide selected from the group consisting of BaO, SrO, CaO, MgO and ZnO);
and
a ratio amoung amounts of B.sub.2 O.sub.3, SiO.sub.2 and MO in said additional component being within a area in a ternary system diagram of mol % having six vertexes of first to sixth vertexes, wherein:
said first vertex A represents a conditon in which amounts of B.sub.2 O.sub.3 is 1 mol %, SiO.sub.2 is 80 mol % and MO is 19 mol %;
said second vertex B represents a conditon in which amounts of B.sub.2 O.sub.3 is 1 mol %, SiO.sub.2 is 39 mol % and MO is 60 mol %;
said third vertex C represents a condition in which amounts of B.sub.2 O.sub.3 is 30 mol %, SiO.sub.2 is 0 mol % and MO is 70 mol %;
said fourth vertex D represents a condition in which amounts of B.sub.2 O.sub.3 is 90 mol %, SiO.sub.2 is 0 mol % and MO is 10 mol%;
said fifth vertex E represents a condition in which amounts of B.sub.2 O.sub.3 is 90 mol %, SiO.sub.2 is 10 mol % and MO is 0 mol %;
and
said sixth vertex F represents a condition in which amounts of B.sub.2 O.sub.3 is 20 mol %, SiO.sub.2 is 80 mol % and MO is 0 mol %.

19 more elements

A method for fabricating a ceramic capacitor, comprising the steps of:

providing a mixture of non-sintered ceramic powder;
forming a non-sintered ceramic sheet comprising said mixture;
fabricating a laminated structure in which said non-sintered ceramic sheet is sandwiched between at least two conductive paste layers;
firing said laminated structure under a non-oxidation atmosphere;
and
heating said fired laminated structure under an oxidation atmosphere;
said mixture of non-sintered ceramic powder comprising a basic component of 100 weight portions and an additional component in the range of 0.2 to 5 weight portions;
said basic component comprising a material represented by the following formula:
(1-.alpha.){(Ba.sub.k-x-z M.sub.x L.sub.z)O.sub.k (Ti.sub.1-y R.sub.y)O.sub.2-y/2 }+.alpha.BaZrO.sub.3
where, M is Mg and/or Zn, L is Ca and/or Sr, R is one or more metal elements selected from a group consisting of Sc, Y, Gd, Dy, Ho, Er, Yb, Tb, Tm and Lu;
and .alpha., k, x, z and y are numerals fulfilling the following conditions:
0.005.ltoreq..alpha..ltoreq.0.04
1.00.ltoreq.k.ltoreq.1.05
0<x<0.10
0<z.ltoreq.0.05
0.01.ltoreq.x+z.ltoreq.0.10
0<y.ltoreq.0.04;
said additional component comprising Li.sub.2 O, SiO.sub.2, CaO and MO wherein said MO is at least one metal oxide selected from the group consisting of BaO, SrO, CaO, MgO and ZnO);
and
a ratio among amounts of Li.sub.2 O, SiO.sub.2, CaO and MO in said additional component being within an area in a ternary system diagram of mol % having five vertexes of first to fifth vertexes, wherein:
said first vertex A represents a condition in which amounts of Li.sub.2 O is 1 mol %, SiO.sub.2 is 80 mol % and MO is 19 mol %;
said second vertex B represents a condition in which amounts of Li.sub.2 O is 1 mol %, SiO.sub.2 is 39 mol % and MO is 60 mol %;
said third vertex C represents a condition in which amounts of Li.sub.2 O is 30 mol %, SiO.sub.2 is 30 mol % and MO is 40 mol %;
said fourth vertex D represents a condition in which amounts of Li.sub.2 O is 50 mol %, SiO.sub.2 is 50 mol % and MO is 0 mol %;
and
said fifth vertex E represents a condition in which amounts of Li.sub.2 O is 20 mol %, SiO.sub.2 is 80 mol % and MO is 0 mol %.

23 more elements

A method for fabricating a ceramic capacitor, comprising the steps of:

providing a mixture of non-sintered ceramic powder;
forming a non-sintered ceramic sheet comprising said mixture;
fabricating a laminated structure in which said non-sintered ceramic sheet is sandwiched between at least two conductive paste layers;
firing said laminated structure under a non-oxidation atmosphere;
and
heating said fired laminated structure under an oxidation atmosphere;
said mixture of non-sintered ceramic powder comprising a fired mixture of a basic component of 100 weight portions and an additional component in the range of 0.2 to 5 weight portions:
said basic component comprising a material represented by the following formula:
(1-.alpha.){(Ba.sub.k-x-z M.sub.x L.sub.z)O.sub.k (Ti.sub.1-y R.sub.y)O.sub.2-y/2 }+.alpha.BaZrO.sub.3
where, M is Mg and/or Zn, L is Ca and/or Sr, R is one or more metal elements selected from the group consisting of Sc, Y, Gd, Dy, Ho, Er, Yb, Tb, Tm and Lu;
and .alpha., k, x, z and y are numerals fulfilling the following conditions:
0. 005.ltoreq..alpha..ltoreq.0.04
1.00.ltoreq.k.ltoreq.1.05
0<x<0.10
0<z.ltoreq.0.05
0.01.ltoreq.=x+z.ltoreq.0.10
0<y.ltoreq.0.04;
said additional component comprising B.sub.2 O.sub.3, SiO.sub.2 and MO (wherein said MO is at least one metal oxide selected from the group consisting of BaO, SrO, CaO, MgO and ZnO;
and
a ratio among amount of B.sub.2 O.sub.3, SiO.sub.2 and MO in said additional component being within an area in a ternary system diagram of mol % having six vertexes of first to sixth vertexes, wherein:
said first vertex A represents a condition in which amounts of B.sub.2 O.sub.3 is 1 mol %, SiO.sub.2 is 80 mol % and MO is 19 mol %;
said second vertex B represents a conditon in which amounts of B.sub.2 O.sub.3 is 1 mol %, SiO.sub.2 is 39 mol % and MO is 60 mol %;
said third vertex C represents a condition in which amounts of B.sub.2 O.sub.3 is 30 mol %, SiO.sub.2 is 0 mol % and MO is 70 mol %;
said fourth vertex D represents a condition in which amounts of B.sub.2 O.sub.3 is 90 mol %, SiO.sub.2 is 0 mol % and MO is 10 mol %;
said fifth vertex E represents a condition in which amounts of B.sub.2 O.sub.3 is 90 mol %, SiO.sub.2 is 10 mol % and MO is 0 mol %;
and
said sixth vertex F represents a condition in which amounts of B.sub.2 O.sub.3 is 20 mol %, SiO.sub.2 is 80 mol % and MO is 0 mol %.

24 more elements

Dependencies are inferred from the claim text.