Low temperature sinterable and low loss dielectric ceramic compositions and method thereof

• US 6,743,744 B1
• Filed: 05/17/2002
• Issued: 06/01/2004
• Est. Priority Date: 05/03/2000
• Status: Expired due to Fees

• Current Assignee: Korea Advanced Institute of Science and Technology
• Original Assignee: Korea Advanced Institute of Science and Technology
• Inventors: Kim, Hyo-Tae, Kim, Yoon-Ho
• Primary Examiner(s): BRUNSMAN, DAVID M
• Application Number:
  US10/019,666
• Time in Patent Office: 746 Days
• Field of Search: 501/134, 501/136, 361/321.4, 361/321.5
• US Class Current: 501/134
• CPC Class Codes: C04B 35/462 based on titanates
• CPC Class Codes: H01B 3/12 ceramics

Abstract

A low loss high-frequency dielectric ceramic composition for sintering at a low temperature and method of manufacturing the same which is characterized in that excellent dielectric properties such as a much lower sintering temperature and higher quality coefficient and dielectric constant, compared to a conventional high-frequency ceramic composition, a stabilized temperature coefficient, and a temperature compensating property varied according to a composition, are implemented using a low-priced material such as ZnO—Mo (M═Mg, Co, Ni)—TiO₂. In addition, Ag, Cu, an alloy thereof, or an Ag/Pd alloy can be used as an internal electrode. Thus, the composition of the present invention can be used as a dielectric material for all sorts of high-frequency devices, such as a multilayer chip capacitor, multilayer chip filter, multilayer chip capacitor/inductor composite device and module, low temperature sintered substrate, resonator or filter and ceramic antenna.

Claims

1. A high frequency dielectric ceramics composition constituted by combining a combination of (Zn₁₋

xM_x)TiO₃ and yTiO₂ as a main component, into which one of 0˜

5 wt % B₂O₃, 0˜

5 wt % H₃BO₃, 0˜

5 wt % SiO₂—

K₂O glass, 0˜

5 wt % B₂O₃ and SiO₂—

K₂O glass, or 0˜

5 wt % H₃BO₃ and SiO₂—

K₂O glass is added as an additive, satisfies conditions of M is Mg, Co or Ni, ‘

x’

is 0<

x≦

0.55 in case of Mg and ‘

x’

is 0<

x≦

1.0 in case of Co, and 0<

x≦

1.0 in case of Ni, and 0<

y≦

0.6.

2. High frequency devices comprising the composition of claim 1.

3. The high frequency devices of claim 2, wherein the high frequency devices are selected from the group consisting of a stacked chip capacitor, a stacked chip filter, a stacked chip capacitor/inductor composite device and a module, a low-temperature sintered board, a resonator,a filter, a ceramic antenna and combinations thereof.

4. A high frequency dielectric ceramics composition preparation method in which material powder of ZnO, MO (in this respect, MO is MgO, CoO or NiO) and TiO₂ is weighed according to a composition range of (Zn₁₋

xM_x)TiO₃ and yTiO₂ (M is one of Mg, Co and Ni, x is 0≦

x≦

0.55 in case of Mg, x is 0≦

x≦

1 in case of Co, x is 0≦

x≦

1 in case of Ni, and y is 0≦

y≦

0.6), mixed and dried,

the dried powder is calcined at a temperature of 850˜

950°

C.,

the calcined powder is mixed with one of 0˜

5 wt % B₂O₃, 0˜

5 wt % H₃BO₃, 0˜

5 wt % SiO₂—

K₂O glass, 0˜

5 wt % B₂O₃ and SiO₂—

K₂O glass, or 0˜

5 wt % H₃BO₃ and SiO₂—

K₂O glass as an additive,

the mixed powder is crushed,

the crushed power is shaped,

the shaped body is fired at a temperature of 800˜

925°

C., and

(Zn<sub>1−

x</sub>M_x)TiO₃ is calcined at a temperature corresponding to a region (region II) of below a phase dissociation temperature as shown in FIG. 1 to obtain (Zn<sub>1−

x</sub>M_x)TiO₃(M is Mg, Co or Ni) of a single phase of rhombohedral/hexagonal crystal.

5. The method of claim 4, wherein the shaped body is made in a manner that an aqueous solution adding a PVA binder is sprayed onto the crushed powder to make a granule, to which a pressure is applied.

6. The method of claim 5, further comprises a step for maintaining the shaped body at a temperature of 300˜

500°

C. for a predetermined time and removing the binder.

7. The method of claim 4, wherein (Zn₁₋

xM₁)TiO₃ is first calcined, and the calcined (Zn<sub>1−

x</sub>M_x)TiO₃ is mixed with one of 0˜

5 wt % B₂O₃, 0˜

5 wt % H₃BO₃, 0˜

5 wt % SiO₂—

K₂O glass, 0˜

5 wt % B₂O₃ and SiO₂—

K₂O glass, or 0˜

5 wt % H₃BO₃ and SiO₂—

K₂O glass as an additive, and then fired.

8. A high frequency dielectric ceramics composition constituted by combining a combination (Zn₁₋

aMg<sub>1−

b</sub>Co<sub>1−

c</sub>Ni<sub>1−

d</sub>)TiO₃ and yTiO₂ as a main component, into which one of 0˜

5 wt % B₂O₃, 0˜

5 wt % H₃BO₃, 0˜

5 wt % SiO₂—

K₂O glass, 0˜

5 wt % B₂O₃ and SiO₂—

K₂O glass, or 0˜

5 wt % H₃BO₃ and SiO₂—

K₂O glass is added as an additive, satisfies conditions of 0<

a≦

1, 0<

b≦

1, 0<

c≦

1, 0<

d≦

1 and 0<

y≦

0.6.