Electronic device for voltage switchable dielectric material having high aspect ratio particles

• US 7,981,325 B2
• Filed: 02/10/2010
• Issued: 07/19/2011
• Est. Priority Date: 07/29/2006
• Status: Active Grant

• Current Assignee: Littelfuse Incorporated
• Original Assignee: Shocking Technologies, Inc.
• Inventors: Kosowsky, Lex, Fleming, Robert
• Primary Examiner(s): Kopec; Mark
• Assistant Examiner(s): Thomas; Jaison P
• Application Number:
  US12/703,701
• Publication Number:
  US 20100141376A1
• Time in Patent Office: 524 Days
• Field of Search: 252/500, 252/511, 252/512, 252/519.33, 361/56, 361/118, 338/21
• US Class Current: 252/511
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: H01B 1/22 the conductive material comprising metals or alloys
• CPC Class Codes: H01B 1/24 the conductive material comprising carbon-silicon compounds, carbon or silicon
• CPC Class Codes: H01C 17/0652 containing carbon or carbides
• CPC Class Codes: H01C 7/1006 Thick film varistors
• CPC Class Codes: H01C 7/105 Varistor cores H01C7/12 takes precedence
• CPC Class Codes: H05K 1/0257 Overvoltage protection
• CPC Class Codes: H05K 1/0259 Electrostatic discharge [ESD] protection
• CPC Class Codes: H05K 1/0373 containing additives, e.g. fillers H05K1/036 takes precedence
• CPC Class Codes: H05K 1/167 incorporating printed resistors
• CPC Class Codes: H05K 2201/0248 Needles or elongated particles; Elongated cluster of chemically bonded particles
• CPC Class Codes: H05K 2201/0257 Nanoparticles
• CPC Class Codes: H05K 2201/026 Nanotubes or nanowires
• CPC Class Codes: H05K 2201/0272 Mixed conductive particles, i.e. using different conductive particles, e.g. differing in shape
• CPC Class Codes: H05K 2201/0738 Use of voltage responsive materials, e.g. voltage switchable dielectric or varistor materials
• CPC Class Codes: H05K 2203/0723 Electroplating, e.g. finish plating
• CPC Class Codes: H05K 2203/105 Using an electrical field; Special methods of applying an electric potential
• CPC Class Codes: H05K 3/188 by direct electroplating
• CPC Class Codes: Y10S 977/742 Carbon nanotubes, CNTs
• CPC Class Codes: Y10S 977/779 Possessing nanosized particles, powders, flakes, or clusters other than simple atomic impurity doping
• CPC Class Codes: Y10T 428/30 : Self-sustaining carbon mass or layer with impregnant or other layer
• CPC Class Codes: Y10T 428/31678 : Of metal

Abstract

One or more embodiments provide for a device that utilizes voltage switchable dielectric material having semi-conductive or conductive materials that have a relatively high aspect ratio for purpose of enhancing mechanical and electrical characteristics of the VSD material on the device.

Claims

1. An electronic device comprising:

a layer of voltage switchable dielectric (VSD) material formed by;

(i) applying a mixture to a substrate, the mixture comprising a polymer binder, a first set of conductor and/or semi-conductor particles, and a second set of nanoscale high aspect ratio (HAR) particles other than said first set of conductor and/or semi-conductor particles; and

;

(ii) curing the mixture on the substrate;

wherein an amount of particles dispersed in the binder, including the first set of conductor and/or semiconductor particles and the second set of nanoscale HAR particles, is sufficiently low so that a percolation threshold of the VSD material is not reached.

2. The electronic device of claim 1, further comprising:

a first electrode and a second electrode, and

wherein the mixture is applied to a span between the first and second electrode.

3. The electronic device of claim 1, wherein the layer of VSD material is provided as a layer within a thickness of the substrate.

4. The electronic device of claim 3, wherein the layer of VSD material underlies one or more contact elements for connecting the substrate to another device, and wherein the one or more contact elements include an aperture to electrically connect a surface of an individual contact element to the layer of VSD material.

5. The electronic device of claim 1, wherein the electronic device is a device selected from a group consisting of a light-emitting diode, a radio-frequency device, a discrete device, and a semi-conductor package.

6. The electronic device of claim 1, wherein the first set of conductor and/or semi-conductor particles and the second set of nanoscale high aspect ratio (HAR) particles are substantially uniformly distributed in the binder.

7. The device of claim 6, wherein the second set of nanoscale high aspect ratio (HAR) particles comprise single and/or multi-walled carbon nanotubes.

8. The device of claim 1, wherein the conductor and/or semiconductor particles include a metal or a metal complex.