Device applications for voltage switchable dielectric material having high aspect ratio particles

• US 7,968,014 B2
• Filed: 02/10/2010
• Issued: 06/28/2011
• Est. Priority Date: 07/29/2006
• Status: Expired due to Fees

• 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:
  US12/703,674
• Publication Number:
  US 20100139956A1
• Time in Patent Office: 503 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. A device comprising:

a layer of voltage switchable dielectric (VSD) material, wherein the VSD material comprises;

a polymer binder;

a first set of particles consisting of nanoscale high aspect ratio (HAR) particles that are conductive or semi-conductive, the first set of nanoscale HAR particles dispersed within the binder; and

a second set of particles, other than said first set of nanoscale HAR particles, consisting of conductor and/or semiconductor particles;

said second set of conductor and/or semiconductor particles dispersed within the binder;

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

2. The device of claim 1, wherein the first set of nanoscale HAR particles and the second set of conductor and/or semiconductor particles are substantially uniformly dispersed in the polymer binder.

3. The device of claim 1, wherein the first set of nanoscale HAR particles include single and/or multi-walled carbon nanotubes.

4. The device of claim 1, wherein the device is a printed circuit board.

5. The device of claim 4, wherein the layer of VSD material is provided within the printed circuit board.

6. The device of claim 4, wherein the layer of VSD material is provided at a surface of the printed circuit board.

7. The device of claim 1, wherein the device is selected from a group consisting of a discrete device, a semi-conductor package, a display device or backplane, and a light-emitting diode.

8. The device of claim 1, wherein the layer of VSD material includes a metal or a metal complex.

9. The device of claim 1, wherein the first set of nanoscale HAR particles include inorganic particles.

10. The device of claim 1, wherein the first set of nanoscale HAR particles include metal particles.

11. The device of claim 1, wherein the first set of nanoscale HAR particles include nanorods and nanowires.

12. The device of claim 1, wherein the first set of nanoscale HAR particles include Antimony Tin Oxide (ATO).

13. The device of claim 1, wherein the device is a printed circuit board, thin film electronic device, light emitting diode device, radio-frequency device, or radio frequency identification (RFID) device.

14. The device of claim 1, wherein the device includes a printed circuit board, and one or more components are attached to the printed circuit board, and wherein the layer of the VSD material is provided within the printed circuit board to provide protection to the one or more attached components.

15. The device of claim 14, wherein the one or more components attached to the printed circuit board include a semiconductor chip, a circuit element, a liquid crystal display, an organic light emissive display, an electrochromic display, an electrophoretic display, or a back plane driver for an electronic component.

16. The device of claim 1, wherein the device is a semiconductor chip, a liquid crystal display, an organic light emissive display, an electrochromic display, an electrophoretic display, or a back plane driver for an electronic component.

17. The device of claim 1, wherein the device is a wireless communication device.

18. The device of claim 1, wherein the device incorporates a liquid crystal display, an organic light emissive display, an electrochromic display, or an electrophoretic display.

19. The device of claim 1, further comprising:

one or more components; and

wherein the layer of VSD material is positioned to protect the one or more components against a transient electrical event; and

wherein the layer of VSD material is positioned to carry current from the transient electrical event to a grounding plane to protect the one or more components.