US5959829A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chip capacitor electromagnetic interference filter
Assignee: Greatbatch Ltd
•
Filing: 1998-02-18
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Granted: 1999-09-28
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Expires: 2018-02-18
Abstract
Abstract An electromagnetic interference (EMI) filter capacitor assembly is provided for shielding and decoupling a conductive terminal pin or lead of the type used, for example, in an implantable medical device against passage of external interference signals. The EMI filter is constructed of relatively inexpensive ceramic chip capacitors which replace relatively expensive feedthrough capacitors as found in the prior art. The chip capacitors are mounted directly onto a hermetic feedthrough terminal in groups of two or more which vary in physical size, dielectric material and capacitance value so that they self-resonate at different frequencies. This "staggering" of resonant frequencies and direct installation at the hermetic terminal provides the EMI filter with sufficient broadband frequency attenuation. In one preferred form, multiple chip capacitor groupings are mounted onto a common base structure, with each capacitor grouping associated with a respective terminal pin. In another preferred form, a non-conductive substrate is provided with metalized circuit traces to better accommodate the mounting of the chip capacitors. Additionally, novel chip capacitor geometry/termination-metallization is provided which significantly reduces the internal inductance of the capacitor to improve its high frequency performance as an EMI filter.
Inventors
- 👤 Robert A. Stevenson
- 👤 Donald K. Haskell
- 👤 Richard L. Brendel
- 👤 Jason Woods
- 👤 Mike Louder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:01
CPC Classifications
H; H03; H03H; H03H1/00; H03H1/0007; A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/36; A61N1/372; A61N1/375; A61N1/3752; A61N1/3754; A61N1/362; A61N1/37; A61N1/3718
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
112 words
An electromagnetic interference (EMI) filter assembly disposed at a point of lead penetration through a conductive substrate, comprising: at least one conductive terminal associated with the point of lead penetration through the conductive substrate; means for mounting the at least one conductive terminal for passage through an opening formed in the conductive substrate with the conductive terminal and the substrate in non-conductive relation; and a plurality of chip capacitors of differing capacitance values each having first and second sets of electrode plates, the first set of electrode plates being conductively coupled to the at least one conductive terminal, and the second set of electrode plates being conductively coupled to the conductive substrate.
Claim 2
Dependent Claim
112 words
An electromagnetic interference (EMI) filter assembly disposed at a point of lead penetration through a conductive substrate, comprising: at least one conductive terminal associated with the point of lead penetration through the conductive substrate; means for mounting the at least one conductive terminal for passage through an opening formed in the conductive substrate with the conductive terminal and the substrate in non-conductive relation; and a plurality of chip capacitors of differing capacitance values each having first and second sets of electrode plates, the first set of electrode plates being conductively coupled to the at least one conductive terminal, and the second set of electrode plates being conductively coupled to the conductive substrate.
Claim 3
Dependent Claim
52 words
The assembly of claim 1, wherein the at least one conductive terminal comprises a plurality of conductive terminals associated with the point of lead penetration through the conductive substrate, and wherein the assembly includes a plurality of chip capacitors of differing capacitance values associated with each of the plurality of conductive terminals.
Claim 4
Dependent Claim
34 words
The assembly of claim 2, including a terminal-to-terminal chip capacitor having a first set of electrode plates coupled to one conductive terminal, and a second set of electrode plates coupled to another conductive terminal.
Claim 5
Dependent Claim
18 words
The assembly of claim 2, including asymmetrical groupings of chip capacitors relative to the plurality of conductive terminals.
Claim 6
Dependent Claim
28 words
The assembly of claim 1, wherein the conductive substrate comprises metallization applied to an insulative substrate, and wherein the metallization further forms the at least one conductive terminal.
Claim 7
Dependent Claim
67 words
The assembly of claim 1, wherein the plurality of chip capacitors incorporate a reduced inductance design wherein the first set of electrode plates terminates on one side of the chip capacitors perpendicular to the first set of electrode plates, and the second set of electrode plates terminates on at least the remaining sides of the plurality of chip capacitors perpendicular to the second set of electrode plates.
Claim 8
Dependent Claim
42 words
The assembly of claim 6, wherein the one side of the chip capacitors whereat the first set of electrode plates terminate includes a semicircular recess, and wherein the at least one conductive terminal includes a terminal pin received within the semicircular recess.
Claim 9
Dependent Claim
26 words
The assembly of claim 6, wherein the chip capacitors comprise a wedge-shaped chip capacitor having the second set of electrode plates terminating on three sides thereof.
Claim 10
Dependent Claim
141 words
An electromagnetic interference (EMI) filter assembly, comprising: at least one conductive terminal; means for mounting the at least one conductive terminal within an opening formed in a conductive substrate, with the conductive terminal and the substrate in non-conductive relation; a first chip capacitor having first and second sets of electrode plates, wherein the first set of electrode plates is conductively coupled to the at least one conductive terminal, and the second set of electrode plates is conductively coupled to the conductive substrate; and a second chip capacitor having a capacitance value different from that of the first capacitor, the second chip capacitor having first and second sets of electrode plates, wherein the first set of electrode plates is conductively coupled to the at least one conductive terminal, and the second set of electrode plates is conductively coupled to the conductive substrate.
Claim 11
Dependent Claim
141 words
An electromagnetic interference (EMI) filter assembly, comprising: at least one conductive terminal; means for mounting the at least one conductive terminal within an opening formed in a conductive substrate, with the conductive terminal and the substrate in non-conductive relation; a first chip capacitor having first and second sets of electrode plates, wherein the first set of electrode plates is conductively coupled to the at least one conductive terminal, and the second set of electrode plates is conductively coupled to the conductive substrate; and a second chip capacitor having a capacitance value different from that of the first capacitor, the second chip capacitor having first and second sets of electrode plates, wherein the first set of electrode plates is conductively coupled to the at least one conductive terminal, and the second set of electrode plates is conductively coupled to the conductive substrate.
Claim 12
Dependent Claim
35 words
The assembly of claim 9, wherein the at least one conductive terminal comprises a plurality of conductive terminals, and wherein a plurality of chip capacitors are associated with each of the plurality of conductive terminals.
Claim 13
Dependent Claim
32 words
The assembly of claim 10, including a terminal-to-terminal chip capacitor having one set of electrode plates coupled to one conductive terminal, and another set of electrode plates coupled to another conductive terminal.
Claim 14
Dependent Claim
18 words
The assembly of claim 10, including asymmetrical groupings of chip capacitors relative to the plurality of conductive terminals.
Claim 15
Dependent Claim
21 words
The assembly of claim 9, wherein the conductive substrate comprises a ferrule conductively attachable to a housing for an electronic device.
Claim 16
Dependent Claim
21 words
The assembly of claim 9, wherein the at least one conductive terminal and the conductive substrate have matched coefficients of expansion.
Claim 17
Dependent Claim
16 words
The assembly of claim 14, wherein the conductive substrate comprises metallization applied to an insulative substrate.
Claim 18
Dependent Claim
21 words
The assembly of claim 15, wherein the metallization applied to the insulative substrate further forms the at least one conductive terminal.
Claim 19
Dependent Claim
71 words
The assembly of claim 9, wherein the at least one of the first or second chip capacitors comprises a reduced inductance design wherein the first set of electrode plates terminates on one side of the chip capacitor perpendicular to the first set of electrode plates, and the second set of electrode plates terminates on at least the remaining sides of the chip capacitor perpendicular to the second set of electrode plates.
Claim 20
Dependent Claim
25 words
The assembly of claim 17, wherein the one side of the chip capacitor, whereat the first set of electrode plates terminate includes a semicircular recess.
Claim 21
Dependent Claim
21 words
The assembly of claim 18, wherein the at least one conductive terminal includes a terminal, pin received within the semicircular recess.
Claim 22
Dependent Claim
29 words
The assembly of claim 17, wherein the at least one chip capacitor comprises a wedge-shaped chip capacitor having the second set of electrode plates terminating on three sides thereof.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-09-27 | 2003-03-29 | 2003-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-09-27 | 2007-03-29 | 2007-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-09-27 | 2011-03-29 | 2011-09-28 | $7700.00 | Window Closed / Lapsed |