METALLIC PASTES AND INKS
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.
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 −4 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 −4 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 −4 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 −5 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.