Dielectric ceramic composition and method for manufacturing multilayered components using the same

• US 6,620,750 B2
• Filed: 09/05/2001
• Issued: 09/16/2003
• Est. Priority Date: 05/18/2001
• Status: Expired due to Fees

• Current Assignee: Seoul National University Industry Foundation (Seoul National University)
• Original Assignee: Kook-Sun Hong
• Inventors: Kim, Dong-Wan, Kim, Jin-Young, Park, Jong-Sung, Kwon, Do-Kyun
• Primary Examiner(s): BRUNSMAN, DAVID M
• Application Number:
  US09/945,717
• Publication Number:
  US 20030004051A1
• Time in Patent Office: 741 Days
• Field of Search: 501/134, 501/135, 264/615, 264/618, 361/321.4
• US Class Current: 501/134
• CPC Class Codes: B32B 18/00 Layered products essentially comprising ceramics, e.g. refractory products
• CPC Class Codes: B32B 2311/08 Silver
• CPC Class Codes: C04B 2235/3206 Magnesium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3224 Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• CPC Class Codes: C04B 2235/3225 Yttrium oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3227 Lanthanum oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3241 Chromium oxides, chromates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3251 Niobium oxides, niobates, tantalum oxides, tantalates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3272 Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite
• CPC Class Codes: C04B 2235/3279 Nickel oxides, nickalates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3281 Copper oxides, cuprates or oxide-forming salts thereof, e.g. CuO or Cu2O
• CPC Class Codes: C04B 2235/3284 Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof
• CPC Class Codes: C04B 2235/3291 Silver oxides
• CPC Class Codes: C04B 2235/3293 Tin oxides, stannates or oxide forming salts thereof, e.g. indium tin oxide [ITO]
• CPC Class Codes: C04B 2235/3294 Antimony oxides, antimonates, antimonites or oxide forming salts thereof, indium antimonate
• CPC Class Codes: C04B 2235/3298 Bismuth oxides, bismuthates or oxide forming salts thereof, e.g. zinc bismuthate
• CPC Class Codes: C04B 2235/3409 Boron oxide, borates, boric acids, or oxide forming salts thereof, e.g. borax
• CPC Class Codes: C04B 2235/6025 Tape casting, e.g. with a doctor blade
• CPC Class Codes: C04B 2235/604 Pressing at temperatures other than sintering temperatures
• CPC Class Codes: C04B 2235/77 : Density
• CPC Class Codes: C04B 2237/408 : Noble metals, e.g. palladium, platina or silver
• CPC Class Codes: C04B 2237/704 : of one or more of the ceramic layers or articles
• CPC Class Codes: C04B 35/495 : based on vanadium, niobium, tantalum, molybdenum or tungsten oxides or solid solutions thereof with other oxides, e.g. vanadates, niobates, tantalates, molybdates or tungstates
• CPC Class Codes: C04B 35/6303 : Inorganic additives
• CPC Class Codes: H01G 4/1209 : characterised by the ceramic dielectric material H01G4/1272, H01G4/1281 take precedence

Abstract

The present invention discloses dielectric ceramic compositions having dielectric properties suitable for high frequency bands, such as microwave and millimetric wave, and a method for manufacturing multilayered components, such as chip LC filters, chip duplexers, and dielectric filters for PCS, using the dielectric ceramic compositions. The dielectric ceramic composition not only possesses low dielectric loss, a high dielectric constant, and temperature stability, but are also capable of being sintered at low temperatures and simultaneously baked with metal electrodes, including silver, copper, silver/palladium. Therefore, the dielectric composition can be applied to temperature stable capacitors (NPO MLCC), microwave oscillators, substrates, filters, planar antenna and on the like. The dielectric composition are represented by the general formula:

A_x′A_1−x″B_y′B_1−y″O₄

where A′ and A″ are La, Nd, Y and Al; B′ and B″ are Nb and Ta.

Claims

1. A dielectric ceramic composition comprising, (A) at least one oxide selected from the group consisting of La₂O₃, Nd₂O₃, Al₂O₃ and Y₂O₃, and (B) at least one oxide selected from the group consisting of Nb₂O₅ and Ta₂O₅, at a molar ratio of 1:

1,

wherein said composition is represented by the general formula;

2. The dielectric ceramic composition according to claim 1, further comprising about 0.01 to about 7 parts by weight of at least one sintering aid selected from the group consisting of B₂O₃, CuO, ZnO and Bi₂O₃, based on 100 parts by weight of said composition represented by the formula A′

_xA″

<sub>1−

x</sub>B′

_yB″

<sub>1−

y</sub>O₄.

3. The dielectric ceramic composition according to claim 2, wherein said sintering aid is selected from the group consisting of B₂O₃ and CuO.

4. The dielectric ceramic composition according to claim 1, further comprising about 0.01 to about 7 parts by weight of at least one additive selected from the group consisting of V₂O₅, SnO₂, MgO, NiO, Sb₂O₃, LiF and Ag₂O, based on 100 parts by weight of said composition represented by the formula A′

_xA″

<sub>1−

x</sub>B′

_yB″

<sub>1−

y</sub>O₄.

5. The dielectric ceramic composition according to claim 1, wherein said A′

is La;

said B′

is Nb; and

said.

6. The dielectric ceramic composition according to claim 5, further comprising from about 0.01 to about 7 parts by weight of at least one sintering aid selected from the group consisting of B₂O₃, CuO, ZnO and Bi₂O₃, based on 100 parts by weight of said composition represented by the formula A′

_xA″

<sub>1−

x</sub>B′

_yB″

<sub>1−

y</sub>O₄.

7. The dielectric ceramic composition according to claim 5, further comprising from about 0.01 to about 7 parts by weight of at least one additive selected from the group consisting of V₂O₅, SnO₂, MgO, NiO, Sb₂O₃, LiF and Ag₂O, based on 100 parts by weight of said composition represented by the formula A′

_xA″

<sub>1−

x</sub>B′

_yB″

<sub>1−

y</sub>O₄.

8. The dielectric ceramic composition according to claim 1, wherein said A′

is La; and

said A″

is selected from the group consisting of Nd, Al and Y.

9. The dielectric ceramic composition according to claim 1, wherein said B′

is Nb; and

said B″

is Ta.

10. The dielectric ceramic composition according to claim 1, wherein said A′

is La;

said A″

is selected from the group consisting of Nd, Al and Y;

said B′

is Nb; and

said B″

is Ta.

11. The dielectric ceramic composition according to claim 10, further comprising from about 0.01 to about 7 parts by weight of at least one sintering aid selected from the group consisting of B₂O₃, CuO, ZnO and Bi₂O₃, based on 100 parts by weight of said composition represented by the formula A′

_xA″

<sub>1−

x</sub>B′

_yB″

<sub>1−

y</sub>O₄.

12. The dielectric ceramic composition according to claim 10, further comprising from about 0.01 to about 7 parts by weight of at least one additive selected from the group consisting of V₂O₅, SnO₂, MgO, NiO, Sb₂O₃, LiF and Ag₂O, based on 100 parts by weight of the main composition represented by the formula A′

_xA″

<sub>1−

x</sub>B′

_yB″

<sub>1−

y</sub>O₄.

13. A method for manufacturing multilayered components, comprising the steps of:

mixing a composition represented by the formula A′

_xA″

<sub>1−

x</sub>B′

_yB″

<sub>1−

y</sub>O₄ with either one of a sintering aid and an additive, to form a slurry, said A′ and

said A″

being elements selected from the group consisting of La, Nd, Y and Al, said said B′ and

B″

being elements selected from the group consisting of Nb and Ta, and said x and said y being mole fractions, in the range of 0≦

x≦

1.0, and 0≦

y≦

1.0, respectively;

deaerating said slurry, followed by molding said slurry into a tape form;

printing an inner electrode on said molded tape form by use of a low melting point electrode paste with a melting point of about 1,000°

C. or lower;

laminating said inner electrode-printed tape to at least two layers; and

sintering said laminated tape in a sintering furnace at about 1000°

C. or lower.

14. The method as defined in claim 13, wherein said at least one sintering aid is selected from the group consisting of B₂O₃, CuO, ZnO and Bi₂O₃, wherein said at least one sintering aid is added in an amount from about 0.01 to about 7 parts by weight, based on 100 parts by weight of said composition represented by the formula A′

_xA″

<sub>1−

x</sub>B′

_yB″

<sub>1−

y</sub>O₄.

15. The method according to claim 13, wherein said at least one additive is selected from the group consisting of V₂O₅, SnO₂, MgO, NiO, Sb₂O₃, LiF and Ag₂O, wherein said at least one additive is added in an amount from about 0.01 to about 7 parts by weight, based on 100 parts by weight of said composition represented by A′

_xA″

<sub>1−

x</sub>B′

_yB″

<sub>1−

y</sub>O₄.

16. The method according in claim 13, wherein said A′

is La;

said x is 1;

said B′

is Nb; and

said y is 1.

17. The method according to claim 13, wherein said A′

is La;

said A″

is selected from the group consisting of Nd, Al and Y;

said B′

is Nb; and

said B″

is Ta.