METALLIC PASTES AND INKS

• US 20100000762A1
• Filed: 07/01/2009
• Published: 01/07/2010
• Est. Priority Date: 07/02/2008
• Status: Abandoned Application

• Current Assignee: Ishihara Chemical Co., Ltd.
• Original Assignee: Applied Nanotech Holdings Incorporated (Nano Magic, Inc.)
• Inventors: Yaniv, Zvi, Yang, Mohshi, Roundhill, David Max
• Application Number:
  US12/496,453
• Publication Number:
  US 20100000762A1
• Time in Patent Office: Days
• US Class Current: 174/126.1
• CPC Class Codes: H05K 2201/0257 Nanoparticles inks comprising nanoparticles H05K1/097
• CPC Class Codes: H05K 2201/10287 Metal wires as connectors or conductors
• CPC Class Codes: H05K 2203/087 Using a reactive gas
• CPC Class Codes: H05K 2203/107 Using laser light shaping a substrate by laser ablation H05K3/0026
• CPC Class Codes: H05K 2203/1131 Sintering, i.e. fusing of metal particles to achieve or improve electrical conductivity
• CPC Class Codes: H05K 2203/1453 Applying the circuit pattern before another process, e.g. before filling of vias with conductive paste, before making printed resistors
• CPC Class Codes: H05K 3/1241 by ink-jet printing or drawing by dispensing
• CPC Class Codes: H05K 3/1283 After-treatment of the printed patterns, e.g. sintering or curing methods
• CPC Class Codes: H05K 3/321 by conductive adhesives
• CPC Class Codes: Y10T 29/49169 Assembling electrical component directly to terminal or elongated conductor

Abstract

A metallic composition including a solvent and a plurality of metal nanoparticles dispersed therein is formulated such that curing of the metallic composition on a substrate provides a metallic conductor with a resistivity of about 5×10⁻⁴ Ω·cm or less. Electrical components of an assembly can be interconnected by a metallic conductor formed by curing the metallic composition on a substrate. A metallic composition including metal nanoparticles can be deposited on a substrate and solidified. The metallic composition can be contacted with a metal wire before or after solidification of the metallic composition and secured to the solidified metallic composition.

Claims

1. A metallic paste comprising a solvent and a plurality of metal nanoparticles dispersed therein, wherein said metallic paste is formulated such that curing of said metallic paste results in a metallic conductor with a resistivity of about 5×

10<sup>−

4</sup> Ω

·

cm or less.

2. The metallic paste of claim 1, wherein the metal nanoparticles comprise copper.

3. The metallic paste of claim 1, wherein the curing comprises thermal sintering.

4. The metallic paste of claim 3, wherein the curing comprises thermal sintering in a forming gas comprising hydrogen and nitrogen.

5. The metallic paste of claim 1, wherein the curing comprises photosintering.

6. The metallic paste of claim 5, wherein the curing comprises photosintering in air at an ambient temperature.

7. The metallic paste of claim 5, wherein the photosintering is preceded by thermal sintering of said metallic paste.

8. The metallic paste of claim 7, wherein the thermal sintering of said metallic paste is carried out in a forming gas.

9. The metallic paste of claim 1, wherein the curing occurs at a temperature of about 350°

C. or less.

10. The metallic paste of claim 1, wherein the metallic paste is cured on a polymer substrate.

11. The metallic paste of claim 1, wherein the metal nanoparticles have a mean diameter of about 50 nm to about 200 nm.

12. A method of making a metallic conductor comprising curing a metallic paste to provide the metallic conductor, wherein the metallic conductor has a resistivity of about 5×

10<sup>−

4</sup> Ω

·

cm or less.

13. The method of claim 12, wherein the metallic paste comprises copper nanoparticles.

14. The method of claim 12, wherein the curing comprises thermal sintering in a forming gas.

15. The method of claim 14, wherein the forming gas comprises hydrogen and nitrogen.

16. The method of claim 12, wherein the curing comprises photosintering.

17. The method of claim 16, wherein the curing comprises photosintering in air at an ambient temperature.

18. The method of claim 16, further comprising thermally sintering the metallic paste before the photosintering.

19. The method of claim 16, further comprising thermally sintering the metallic paste in a forming gas before the photosintering.

20. The method of claim 12, wherein the curing occurs at a temperature of about 350°

or less.

21. An electrical assembly comprising first and second electrical components interconnected by a metallic conductor, the metallic conductor comprising a cured metallic paste or ink, wherein the metallic conductor has a resistivity of about 5×

10<sup>−

4</sup> Ω

·

cm or less.

22. The electrical assembly of claim 21, wherein the metallic paste or ink comprises copper nanoparticles.

23. The electrical assembly of claim 21, wherein the cured metallic paste or ink comprises a thermally sintered metallic paste or ink.

24. The electrical assembly of claim 21, wherein the cured metallic paste or ink comprises a photosintered metallic paste or ink.

25. The electrical assembly of claim 21, wherein the metallic conductor has a resistivity of about 2×

10<sup>−

5</sup> Ω

·

cm or less.

26. The electrical assembly of claim 21, wherein the metallic conductor is in direct contact with the first and second electrical components.

27. The electrical assembly of claim 21, wherein the metallic conductor is connected to the first and second electrical components through a via filled with a thermally sintered or photosintered metallic paste.

28. A method of securing a wire to a conductor, the method comprising:

depositing a drop of a metallic composition on a substrate, the metallic composition comprising metal nanoparticles;

inserting a portion of a metal wire in the drop;

sintering the metallic composition; and

securing the wire to the solidified metallic composition.

29. The method of claim 28, wherein the portion of the metal wire is inserted in the metallic composition after the metallic composition is sintered.

30. The method of claim 28, wherein the metal nanoparticles comprise copper.