COG dielectric composition for use with nickel electrodes

Patent metadata

Field	Value
Publication number	US-9704650-B2
Application number	US-201415024166-A
Country	US
Kind code	B2
Filing date	Sep 8, 2014
Priority date	Oct 30, 2013
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

Multilayer ceramic chip capacitors which satisfy COG requirements and which are compatible with reducing atmosphere sintering conditions so that non-noble metals such as nickel and nickel alloys may be used for internal and external electrodes are disclosed. The capacitors exhibit desirable dielectric properties (high capacitance, low dissipation factor, high insulation resistance), excellent performance on highly accelerated life testing, and very good resistance to dielectric breakdown. The dielectric layers comprise a strontium zirconate matrix doped with other metal oxides such as TiO 2 , MgO, B 2 O 3 , CaO, MnO, Nd2O3 and Nb2O5 in various combinations.

First claim

What is claimed:

1. A lead-free and cadmium-free dielectric material comprising a solids portion wherein the solids portion comprises, prior to firing:
no lead and no cadmium;
optionally up to about 1.3 SrTiO 3 ;
from about 70.8 wt % to about 81.7 wt % SrZrO 3 ;
optionally up to about 3.4 wt % CaZrO 3 ;
optionally up to about 7.6 wt % CaTiO 3 ;
from about 11.6 wt % to about 13.5 wt % Sr 2 Nb 2 O 7 ;
optionally up to about 7.1 wt % Nd 2 ZrO 5 ;
from about 0.27 wt % to about 0.38 wt % B 2 O 3 ;
from about 0.31 wt % to about 0.44 wt % MgO; and
optionally up to about 0.06 wt % MnO.

2. A method of forming an electronic component comprising:
applying the dielectric material of claim 1 to a substrate; and
firing the substrate at a temperature sufficient to sinter the dielectric material.

3. The method of claim 2 , wherein the firing is conducted at a temperature of from about 1200° C. to about 1350° C.

4. The method of claim 2 , wherein the firing is conducted in an atmosphere having a partial oxygen pressure of about 10 −12 atm to about 10 −8 atm.

5. A multilayer ceramic chip capacitor comprising a fired collection of:
alternately stacked layers of:
the dielectric material of claim 1 ; and
layers of an internal electrode material comprising a transition metal other than Ag, Au, Pd, or Pt.

6. The multilayer ceramic chip capacitor of claim 5 , wherein the internal electrode material comprises nickel.

7. A method of forming an electronic component comprising:
alternately applying layers of
the dielectric material of claim 1 , and
a metal-containing electrode paste onto a substrate to form a laminar stack;

firing the substrate at a temperature sufficient to sinter the dielectric material;
cutting the laminar stack to a predetermined shape;
separating the cut stack from the substrate; and
firing the stack to sinter the metal in the electrode paste and fuse the oxides in the dielectric material.

8. The method of claim 7 , wherein the layers of dielectric material, after firing, each have a thickness of about 1 microns to about 50 microns.

9. The method of claim 7 , wherein the firing is conducted at a temperature of from about 1200° C. to about 1325° C.

10. The method of claim 7 , wherein the firing is conducted in an atmosphere having a partial oxygen pressure of about 10 −12 atm to about 10 −8 atm.

11. The method of claim 7 , wherein the metal-containing electrode paste comprises nickel.

12. The composition according to claim 1 , wherein the dielectric material exhibits a dielectric constant greater than 31.

13. The electronic component formed by the method of claim 2 , wherein the sintered dielectric material exhibits a dielectric constant greater than 31.

Assignees

• Ferro Corp

Inventors

• Symes Jr Walter J

Classifications

• C04B2237/68

  Forming laminates or joining articles wherein at least one substrate contains at least two different parts of macro-size, e.g. one ceramic substrate layer containing an embedded conductor or electrode · CPC title

• C04B2235/3262

  Manganese oxides, manganates, rhenium oxides or oxide-forming salts thereof, e.g. MnO · CPC title

• C04B2235/5445

  submicron sized, i.e. from 0,1 to 1 micron · CPC title

• C04B2235/3255

  Niobates or tantalates, e.g. silver niobate · CPC title

• H01G4/1236

  based on zirconium oxides or zirconates (H01G4/1263 takes precedence) · CPC title