EMI Voltage Switchable Dielectric Materials Having Nanophase Materials

• US 20110198544A1
• Filed: 02/18/2011
• Published: 08/18/2011
• Est. Priority Date: 02/18/2010
• Status: Abandoned Application

• Current Assignee: Littelfuse Incorporated
• Original Assignee: Littelfuse Incorporated
• Inventors: Wu, Junjun, Kosowsky, Lex, Fleming, Robert, Ranganathan, Thangamani
• Application Number:
  US13/031,071
• Publication Number:
  US 20110198544A1
• Time in Patent Office: Days
• US Class Current: 252/513
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H01B 3/004 with conductive additives or conductive layers
• CPC Class Codes: H05K 1/0254 High voltage adaptations; Electrical insulation details; Overvoltage or electrostatic discharge protection electrostatic discharge protection for electric apparatus in general H05K9/0067, H05K9/0079; Arrangements for regulating voltages or for using plural voltages
• CPC Class Codes: H05K 2201/0738 Use of voltage responsive materials, e.g. voltage switchable dielectric or varistor materials

Abstract

Various embodiments of the invention disclosed herein provide for adjusting the electrical response of a voltage switchable dielectric material by incorporating one or more nanophase materials. Various aspects provide for a VSDM having improved electrical and/or physical properties. In some cases, a VSDM may have improved (e.g., lower) leakage current at a given voltage. A VSDM may have improved resistance to ESD events, and may have improved resistance to degradation associated with protecting against an ESD event.

Claims

1. A voltage switchable dielectric material (VSDM) comprising:

a conductive phase;

an insulating phase; and

a nanophase material that modifies an electrical response of the VSDM.

2. The VSDM of claim 1, wherein the nanophase material includes a semiconducting phase.

3. The VSDM of claim 1, wherein the nanophase material includes an insulating phase.

4. The VSDM of claim 1, wherein the nanophase material includes a Metal Organic Framework (MOF) material.

5. The VSDM of claim 4, wherein the MOF material is at least one of a carboxylate, a Zinc-imidazolate, and an imidazole.

6. The VSDM of claim 1, wherein the nanophase material includes a covalent organic framework material.

7. The VSDM of claim 1, wherein the nanophase material includes a zeolitic imidazolate framework material.

8. The VSDM of claim 1, wherein the nanophase material includes at least one of a terephthalate, a zeolite, an aluminum, an imidazole, a zinc, a copper, and an iron.

9. The VSDM of claim 1, wherein the nanophase material includes a surface area greater than 1,000 m²/g.

10. The VSDM of claim 1, wherein the nanophase material includes a surface area greater than 2,000 m²/g.

11. The VSDM of claim 1, wherein the nanophase material includes a surface area greater than 4,000 m²/g.

12. The VSDM of claim 1, wherein the predetermined porosity of the nanophase material does not exceed 100 nm.

13. The VSDM of claim 1, wherein the predetermined porosity of the nanophase material does not exceed 30 nm.

14. The VSDM of claim 1, wherein the predetermined porosity of the nanophase material does not exceed 10 nm.

15. The VSDM of claim 1, wherein the predetermined porosity of the nanophase material does not exceed 6 nm.

16. A method for modifying an electrical response of a voltage switchable dielectric material (VSDM), the method comprising:

selecting a VSDM material having an electrical response; and

adding a nanophase material to the VSDM to modify the electrical response of the VSDM.

17. The method of claim 16, wherein the amount of the nanophase material added is between 0.01 and 40%.

18. The method of claim 16, wherein the amount of the nanophase material added is between 0.1 and 10%.

19. The method of claim 16, wherein the amount of the nanophase material added is 5.0%.

20. The method of claim 16, wherein the electrical response of the VSDM is a first trigger voltage at a first leakage current and the effective amount of nanophase material reduces the first trigger voltage by 30% at the first leakage current.