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

• US 20080023675A1
• Filed: 07/29/2007
• Published: 01/31/2008
• Est. Priority Date: 08/27/1999
• Status: Active Grant

• Current Assignee: Littelfuse Incorporated
• Original Assignee: Shocking Technologies, Inc.
• Inventors: Kosowsky, Lex, Fleming, Robert
• Granted Patent: US 7,695,644 B2
• Time in Patent Office: Days
• US Class Current: 252/510
• 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: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• 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 2201/0257 Nanoparticles inks comprising nanoparticles H05K1/097
• CPC Class Codes: H05K 2201/0738 Use of voltage responsive materials, e.g. voltage switchable dielectric or varistor materials
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• 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 electroplating H05K2203/0723
• CPC Class Codes: H05K 3/188 by direct electroplating
• CPC Class Codes: H10K 50/805 Electrodes
• CPC Class Codes: H10K 50/88 Terminals, e.g. bond pads

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

a binder;

high aspect ratio (HAR) particles that are conductive or semi-conductive and dispersed as nanoscale particles within the binder; and

conductor and/or semiconductor particles;

said conductor and/or semiconductor particles being distributed in the binder;

wherein HAR particles and said conductor and/or semiconductor particles are combined to provide said composition with a characteristic of being (i) dielectric in absence of a voltage that exceeds a characteristic voltage level, and (ii) conductive with application of said voltage exceeding said characteristic voltage level.

2. The device of claim 1, wherein the conductive organic material and the conductor or semiconductor particles the formation of VSD material are substantially uniformly distributed in an overall thickness of the binder.

3. The device of claim 2, wherein the organic material the formation of VSD material includes single and/or multi-walled carbon nanotubes.

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

5. The device of claim 4, wherein the formation of VSD material is provided as a layer within the substrate device.

6. The device of claim 4, wherein the formation of VSD material is provided as trace elements on a surface of the substrate device.

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

8. The device of claim 1, wherein said organic material of the formation of VSD material includes a pure carbon compound corresponding to one of carbon graphite, carbon fiber, or a diamond powder.

9. The device of claim 1, wherein the conductor and/or semiconductor particles the formation of VSD material includes a metal or a metal complex.

10. An electronic device comprising:

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

(i) creating a mixture comprising a binder, metallic and/or inorganic semi-conductor particles, and conductive or semi-conductive organic material;

(ii) applying the mixture to a target location on the device; and

(iii) curing the mixture at the target location.

11. The electronic device of claim 10, further comprising:

a first electrode and a second electrode, and

wherein the target location is a span between the first and second electrode.

12. The electronic device of claim 10, wherein the device corresponds to a substrate device, and wherein the VSD material is provided as a layer that is within a thickness of the substrate.

13. The electronic device of claim 12, wherein the 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 VSD layer.

14. The electronic device of claim 10, 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 or substrate.

15. The electronic device of claim 10, wherein the conductive or semi-conductive organic material and the conductor or semiconductor particles the formation of VSD material are substantially uniformly distributed in an overall thickness of the binder.

16. The device of claim 15, wherein the conductive or semi-conductive organic material of the formation of VSD material includes single and/or multi-walled carbon nanotubes.

17. The device of claim 10, wherein the conductive or semi-conductive organic material of the formation of VSD material includes a pure carbon compound corresponding to one of carbon graphite, carbon fiber, or a diamond powder.

18. The device of claim 10, wherein the conductor and/or semiconductor particles the formation of VSD material includes a metal or a metal complex.

19. A method for electroplating a substrate, the method comprising:

applying a voltage switchable dielectric (VSD) material onto a target region of a device, said VSD material comprising;

a binder;

high aspect ratio (HAR) particles that are conductive or semi-conductive and dispersed as nanoscale particles within the binder; and

conductor and/or semiconductor particles;

said conductor and/or semiconductor particles being distributed in the binder;

wherein HAR particles and said conductor and/or semiconductor particles are combined to provide said composition with a characteristic of being (i) dielectric in absence of a voltage that exceeds a characteristic voltage level, and (ii) conductive with application of said voltage exceeding said characteristic voltage level;

forming a pattern using the VSD material;

applying the voltage that exceeds the characteristic voltage level so that the VSD material is conductive;

while applying the voltage, exposing the target region of the device to an electrolytic medium.