IP Library Granted Patent US 7,670,981
Granted Patent B2
US 7,670,981 · App. 12/257,532 · Granted Mar 2, 2010

C0G multi-layered ceramic capacitor

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Quick Facts
Patent No.
US 7,670,981
App. No.
12/257,532
Granted
Mar 2, 2010
Kind
B2
Abstract

A dielectric ceramic composition in a multilayer ceramic capacitor with a composition of formula: {[(CaO) t (SrO) 1-t ] m [(ZrO 2 ) v (TiO 2 ) 1-v ]} 1-s-x A s E x wherein: A is a transition metal oxide; E is an oxide of an element selected from the group consisting of Ge, Si, Ga and combinations thereof; m is 0.98 to 1.02; t is 0.50 to 0.90; v is 0.8 to 1.0; s and x are selected from the group consisting of: a) 0≦x≦0.08, 0.0001≦s≦0.043 and x≧1.86s; and b) 0≦x≦0.0533, 0.0001≦s≦0.08 and x≦0.667s.

Claims (19)

1. A method for forming a capacitor comprising:

milling to a D50 of less than 1.0 μm a material comprising:

[(CaO) t (SrO) 1-t ] m [(ZrO 2 ) v (TiO 2 ) 1-v]

wherein m is 0.98 to 1.02; and

t is 0.50 to 0.90; and

v is 0.8 to 1.0;

thereby forming a first component (C1);

milling MnO 2 , MnCO 3 or another oxidized form of Mn to a D50 of less than 1.0 μm thereby forming a second component (C2);

milling SiO 2 to a D50 of less than 0.50 μm thereby forming a third component (C3);

combining said first component, said second component and said third component with a solvent in a ratio C1 1-α-β C2 α C3 β thereby forming a coating solution;

applying said coating solution to a tape in an amount selected from the group consisting of a) sufficient to form a ceramic layer over 4.5 μm thick wherein α and β are defined as 0.000186≦β≦0.08, 0.0001≦α≦0.043 and β≧1.86α; and b) sufficient to form a ceramic layer of no more than 4.5 μm thick wherein α and β are defined as 0.0000667≦β≦0.0533, 0.0001≦α≦0.08 and β≦0 667α;

drying said coating solution to form a green coating;

depositing an ink comprising electrode material over said green coating to form electroded green layers;

stacking non-electroded green layers and electroded green layers to form a green capacitor stack;

dicing said capacitor stack to form singular green multilayer chips;

firing said singular green multilayer chips in an atmosphere with a PO 2 of 10 −6 to 10 −16 ; and

forming terminals in electrical contact with said electrode material.

2. The method of claim 1 further comprising:

combining MnO 2 and said SiO 2 and milling said combination prior to said combining.

Assignments (6)
RELEASE OF SECURITY INTEREST Recorded Nov 8, 2018
From: BANK OF AMERICA, N.A.
To: KEMET CORPORATION,; KEMET ELECTRONICS CORPORATION; KEMET BLUE POWDER CORPORATION
Reel/Frame 047450/0926 →
SECURITY AGREEMENT Recorded May 22, 2017
From: KEMET CORPORATION; KEMET ELECTRONICS CORPORATION; KEMET BLUE POWDER CORPORATION
To: BANK OF AMERICA, N.A., AS COLLATERAL AGENT
Reel/Frame 042523/0639 →
SECURITY INTEREST Recorded Oct 5, 2010
From: KEMET ELECTRONICS CORPORATION
To: BANK OF AMERICA, N.A. AS AGENT
Reel/Frame 025150/0023 →
RELEASE OF SECURITY INTEREST RECORDED AT REEL/FRAME 022892/0795 Recorded May 18, 2010
From: K FINANCING, LLC
To: KEMET CORPORATION
Reel/Frame 024397/0774 →
SECURITY AGREEMENT Recorded Jul 1, 2009
From: KEMET CORPORATION
To: K FINANCING, LLC
Reel/Frame 022892/0795 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 24, 2008
From: RANDALL, MICHAEL S.; ANTONIADES, COREY; BARBER, DANIEL E.; XU, XILIN; BEESON, JAMES; PINCELOUP, PASCAL; GURAV, ABHIJIT; POOLE, THOMAS; TAJUDDIN, AZIZUDDIN; BURN, IAN
To: KEMET ELECTRONICS CORPORATION
Reel/Frame 021730/0732 →