US4977357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Overvoltage protection device and material
Assignee: Littelfuse Inc
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Filing: 1988-01-11
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Granted: 1990-12-11
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Expires: 2008-01-11
Abstract
Abstract A material device for electronic circuitry that provides pro-tection from fast transient overvoltage pulses. The electroded device can additionally be tailored to provide electrostatic bleed. Conductive particles are uniformly dispersed in an insulating matrix or binder to provide material having non-linear resistance characteristics. The non-linear resistance characteristics of the material are determined by the interparticle spacing within the binder as well as by the electrical properties of the insulating binder. By tailoring the separation between conductive particles, thereby controlling quantum-mechanical tunneling, the electrical properties of the non-linear material can be varied over a wide range.
Inventors
- 👤 Karen P. Shrier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:12
CPC Classifications
H; H01; H01B; H01B1/00; H01B1/20; H01B1/24; H01B1/14; H01B1/16; H01B1/18; H01B1/22; H01C; H01C7/00; H01C7/10; H01C7/105
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
97 words
A material for placement between and in contact with spaced conductors to provide a non-linear resistance therebetween, said material comprising a matrix formed of a said binder and only closely spaced conductive particles: (a) said closely spaced conductive particles being homogeneously distributed, said particles being in the range 0.1 microns to two hundred microns in size and spaced by said binder to provide electrical conduction by quantum-mechanical tunneling therebetween; and (b) said binder selected to provide the quantum-mechanical tunneling media between said conductive particles and predetermined resistance between said conductive particles in the absence of quantum-mechanical tunneling.
Claim 2
Dependent Claim
97 words
A material for placement between and in contact with spaced conductors to provide a non-linear resistance therebetween, said material comprising a matrix formed of a said binder and only closely spaced conductive particles: (a) said closely spaced conductive particles being homogeneously distributed, said particles being in the range 0.1 microns to two hundred microns in size and spaced by said binder to provide electrical conduction by quantum-mechanical tunneling therebetween; and (b) said binder selected to provide the quantum-mechanical tunneling media between said conductive particles and predetermined resistance between said conductive particles in the absence of quantum-mechanical tunneling.
Claim 3
Dependent Claim
13 words
A material according to claim 1 wherein the binder is an electrical insulator.
Claim 4
Dependent Claim
22 words
A material according to claim 1 wherein the binder material has electrical resistivity ranging from 10 8 to about 10 16 ohm-centimeters.
Claim 5
Dependent Claim
41 words
A material according to claim 1 wherein the binder is a polymer which has had its resistance characteristics modified by addition of materials such as powdered metallic compounds, powdered metallic oxides, powdered semiconductors, organic semi-conductors, organic salts, coupling agents, and dopants.
Claim 6
Dependent Claim
28 words
A material according to claim 1 wherein the binder is selected from the class of organic polymers such as polyethylene, polypropylene, polyvinyl chloride, natural rubbers, urethanes, and epoxies.
Claim 7
Dependent Claim
20 words
A material according to claim 1 wherein the binder is selected from silicone rubbers, fluoropolymers, and polymer blends and alloys.
Claim 8
Dependent Claim
21 words
A material according to claim 1 wherein the binder is selected from the class of materials including ceramics, and refractory alloys.
Claim 9
Dependent Claim
20 words
A material according to claim 1 wherein the binder is selected from the class of materials including waxes and oils.
Claim 10
Dependent Claim
18 words
A material according to claim 1 wherein the binder is selected from the class of materials including glasses.
Claim 11
Dependent Claim
34 words
A material according to claim 1 wherein the binder includes fumed silicon dioxide, quartz, alumina, aluminum trihydrate, feld spar, silica, barium sulphate, barium titanate, calcium carbonate, woodflour, crystalline silica, talc, mica, or calcium sulphate.
Claim 12
Dependent Claim
62 words
A material according to claim 1 wherein the conductive particles include powders of aluminum, beryllium, iron, gold, silver, platinum, lead, tin, bronze, brass, copper, bismuth, cobalt, magnesium, molybdenum, palladium, tantalum, tungsten and alloys thereof, carbides including titanium carbide, boron carbide, tungsten carbide, and tantalum carbide, powders based on carbon including carbon black and graphite, as well as metal nitrides and metal borides.
Claim 13
Dependent Claim
76 words
A material according to claim 1 wherein the conductive particles include uniformly sized hollow or solid glass spheres coated with a conductor such as include powders of aluminum, beryllium, iron, gold, silver, platinum, lead, tin, bronze, brass, copper, bismuth, cobalt, magnesium, molybdenum, palladium, tantalum, tungsten and alloys thereof, carbides including titanium carbide, boron carbide, tungsten carbide, and tantalum carbide, powders based on carbon including carbon black and graphite, as well as metal nitrides and metal borides.
Claim 14
Dependent Claim
21 words
A material according to claim 1 wherein the conductive particles have resistivities ranging from about 10 -1 to 10 -6 ohm-centimeters.
Claim 15
Dependent Claim
28 words
A material according to claim 1 wherein the the percentage, by volume, of conductive particles in the material is greater than about 0.5% and less than about 50%.
Claim 16
Dependent Claim
25 words
A two terminal device utilizing materials in any one of claims 1 through 14 to provide nanosecond transient overvoltage protection to electronic circuitry between terminals.
Claim 17
Dependent Claim
22 words
An electroded device utilizing materials in any one of claims 1 through 14 to provide nanosecond transient overvoltage protection to electronic circuitry.
Claim 18
Dependent Claim
23 words
A leaded electroded device utilizing materials in any one of claims 1 through 14 to provide nanosecond transient overvoltage protection to electronic circuitry.
Claim 19
Independent Claim
24 words
A device utilizing materials in any one of claims 1 through 14 to provide nanosecond transient overvoltage protection to electronic circuitry and electrostatic bleed.
Claim 20
Dependent Claim
25 words
An electroded device utilizing materials in any one of claims 1 through 14 to provide nanosecond transient overvoltage protection to electronic circuitry and electrostatic bleed.
Claim 21
Dependent Claim
26 words
A leaded electroded device utilizing materials in any one of claims 1 through 14 to provide nanosecond transient overvoltage protection to electronic circuitry and electrostatic bleed.
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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) | 1993-12-10 | 1994-06-11 | 1994-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-10 | 1998-06-11 | 1998-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-10 | 2002-06-11 | 2002-12-11 | $7700.00 | Window Closed / Lapsed |