Methods for fabricating current-carrying structures using voltage switchable dielectric materials

• US 20090044970A1
• Filed: 09/24/2008
• Published: 02/19/2009
• Est. Priority Date: 08/27/1999
• Status: Active Grant

• Current Assignee: Littelfuse Incorporated
• Original Assignee: Shocking Technologies, Inc.
• Inventors: Kosowsky, Lex
• Granted Patent: US 9,144,151 B2
• Time in Patent Office: Days
• US Class Current: 174/256
• 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 1/0373 containing additives, e.g. fillers H05K1/036 takes precedence
• CPC Class Codes: H05K 1/167 incorporating printed resistors
• CPC Class Codes: H05K 2201/0215 Metallic fillers
• CPC Class Codes: H05K 2201/0738 Use of voltage responsive materials, e.g. voltage switchable dielectric or varistor materials
• 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: H05K 3/423 characterised by electroplating method
• CPC Class Codes: H05K 3/426 initial plating of through-holes in substrates without metal
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49126 Assembling bases
• CPC Class Codes: Y10T 29/49128 Assembling formed circuit to base
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

A method comprises providing a voltage switchable dielectric material having a characteristic voltage, exposing the voltage switchable dielectric material to a source of ions associated with an electrically conductive material, and creating a voltage difference between the source and the voltage switchable dielectric material that is greater than the characteristic voltage. Electrical current is allowed to flow from the voltage switchable dielectric material, and the electrically conductive material is deposited on the voltage switchable dielectric material. A body comprises a voltage switchable dielectric material and a conductive material deposited on the voltage switchable dielectric material using an electrochemical process. In some cases, the conductive material is deposited using electroplating.

Claims

1. A method for fabricating a current-carrying formation, the method comprising:

providing a first voltage switchable dielectric material having a first characteristic voltage;

exposing the first voltage switchable dielectric material to a first source of ions associated with a first electrically conductive material;

creating a first voltage difference between the first source and the first voltage switchable dielectric material;

the first voltage difference greater than the first characteristic voltage;

allowing electrical current to flow from the first voltage switchable dielectric material; and

depositing the first electrically conductive material on the first voltage switchable dielectric material.

2. The method of claim 1, further comprising:

exposing the first voltage switchable dielectric material to a second source of ions associated with a second electrically conductive material;

creating a second voltage difference between the second source and the first voltage switchable dielectric material;

the second voltage difference greater than the first characteristic voltage;

allowing electrical current to flow from the first voltage switchable dielectric material during application of the second voltage difference; and

depositing the second electrically conductive material on the first voltage switchable dielectric material.

3. The method of claim 1, further comprising:

providing a second voltage switchable dielectric material having a second characteristic voltage;

creating a second voltage difference between the first source and the second voltage switchable dielectric material;

the second voltage difference greater than the second characteristic voltage;

allowing electrical current to flow from the second voltage switchable dielectric material; and

depositing the first electrically conductive material on the second voltage switchable dielectric material.

4. The method of claim 1, further comprising:

creating a second voltage difference between the first source and the first voltage switchable dielectric material;

the second voltage difference greater than the first characteristic voltage; and

depositing the first electrically conductive material on the first voltage switchable dielectric material while the first voltage switchable dielectric material is subject to the second voltage difference.

5. The method of claim 1 wherein the first voltage switchable dielectric material is disposed on at least a portion of a substrate.

6. The method of claim 5 wherein the substrate is flexible.

7. The method of claim 5, wherein the substrate includes any of a printed circuit board, printed wiring board, flex circuit, semiconductor wafer, smart card, or RFID tag.

8. The method of claim 1, wherein the first electrically conductive material is deposited in a pin receptacle.

9. The method of claim 1, wherein the first electrically conductive material is deposited in a via.

10. The method of claim 1 wherein depositing includes electroplating.

11. The method of claim 1 wherein depositing includes plasma depositing.

12. The method of claim 1 wherein depositing includes using an electrostatic process.

13. The method of claim 1 wherein depositing includes pulse plating.

14. The method of claim 1 wherein depositing includes reverse pulse plating.

15. The method of claim 1 further comprising polishing the first electrically conductive material.

16. The method of claim 15 wherein polishing includes chemical-mechanical polishing.

17. The method of claim 1 wherein the first electrically conductive material includes a magnetic material.

18. The method of claim 1, wherein providing includes dissolving an electrode that provides the first source of ions.

19. The method of claim 1, wherein the first electrically conductive material includes any of Au, Ag, Cu, Sn, and Al.

20. The method of claim 1, wherein the first electrically conductive material includes Cu.

21. The method of claim 1, wherein the first electrically conductive material includes Au.

22. The method of claim 1, wherein depositing includes depositing on a bottom surface having a length.

23. The method of claim 1, wherein the first characteristic voltage is between 1 and 100 volts.

24. The method of claim 23, wherein the first characteristic voltage is between 5 and 50 volts.

25. A body including a current-carrying formation fabricated according to claim 1.

26. The method of claim 1, further comprising masking a portion of the first voltage switchable dielectric material such that the masked portion is not exposed to the first source.

27. The method of claim 26, wherein the first electrically conductive material is deposited on an unmasked region of the first voltage switchable dielectric material.

28. A body comprising:

a voltage switchable dielectric material; and

a conductive material deposited on the voltage switchable dielectric material using an electrochemical process.

29. The body of claim 28, wherein the electrochemical process includes electroplating.

30. The body of claim 28, wherein the voltage switchable dielectric material includes a via, and at least a portion of the conductive material is deposited in the via.

31. The body of claim 28, wherein the voltage switchable dielectric material includes a pin receptacle, and at least a portion of the conductive material is deposited in the pin receptacle.

32. A body comprising:

a voltage switchable dielectric material; and

a conductive material bonded to the voltage switchable dielectric material with electrobonds.

33. The body of claim 32, wherein the voltage switchable dielectric material includes a via, and at least a portion of the conductive material is bonded within the via.

34. The body of claim 32, wherein the voltage switchable dielectric material includes a pin receptacle, and at least a portion of the conductive material is bonded within the pin receptacle.

35. A body comprising:

a first conductor;

a second conductor;

a voltage switchable dielectric material separating the first and second conductors; and

a current carrying formation within the voltage switchable dielectric material that electrically connects the first and second conductors.

36. The body of claim 35, wherein the current carrying formation includes a via.

37. The body of claim 35, wherein the current carrying formation is fabricated by depositing in the voltage switchable dielectric material using an electrochemical process.

38. The body of claim 35, wherein any of the first and second conductors is fabricated by depositing on the voltage switchable dielectric material using an electrochemical process.