Method of forming conductive trace

Patent metadata

Field	Value
Publication number	US-9565772-B2
Application number	US-201414907590-A
Country	US
Kind code	B2
Filing date	Jul 22, 2014
Priority date	Jul 29, 2013
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

The present subject matter provides for a multi-layer conductive trace. The trace can be formed by digital printing the individual layers and firing. The individual layers each impart functional characteristics to the conductive trace and each layer has components that can be adjusted to affect the performance characteristics of that particular layer without detrimentally affecting the performance characteristics of the remaining layers.

First claim

What is claimed is:

1. A conductive trace comprising:
an interface layer bonded to a substrate,
a conductive layer on the interface layer,
a redox control layer covering the conductive layer; and
a metal layer in electrical contact with the conductive layer through one or more voids in the redox control layer,
wherein the interface layer and the redox control layer prevent the conductive layer from being exposed to the atmosphere.

2. The conductive trace according to claim 1 , wherein the conductive layer comprises a metal selected from the group consisting of copper, aluminum, nickel, tin, tungsten, zinc, iron, silver, steel, and combinations thereof.

3. The conductive trace according to claim 1 , wherein:
if the substrate comprises glass or ceramic, then the interface layer comprises a glass frit,
if the substrate comprises metal, then the interface layer comprises a dielectric material, and
if the substrate comprises polymer, then the interface layer comprises a silane based adhesion promoter.

4. The conductive trace according to claim 1 , wherein the substrate comprises glass or ceramic, and the interface layer comprises borosilicate glass frit.

5. The conductive trace according to claim 1 , wherein:
the interface layer includes one or more expansion modifiers having a thermal expansion coefficient between that of the conductive layer and that of the substrate, and
the expansion modifier is selected from the group consisting of cordierite, beta eucryptite, quartz, zirconia, alumina, spinels, metal, zinc silicates, magnesium silicates, barium silicates, strontium silicates, barium aluminum silicates, strontium aluminum silicates, lithium alumino silicates, zirconium silicates, barium magnesium silicates, barium titanium silicates, silica, titania and combinations thereof.

6. The conductive trace according to claim 1 , wherein the interface layer includes a silver migration control additive selected from the group consisting of silicon, iron, zinc, glass frits containing sulfur, and combinations thereof.

7. The conductive trace according to claim 1 , wherein the interface layer includes a dielectric material selected from the group consisting of borosilicate glass frits, silica, zirconia, alumina, titania based compounds, and a combination thereof.

8. The conductive trace according to claim 1 , wherein the metal layer is a precious metal layer, wherein the precious metal layer includes one selected from the group consisting of silver, gold, platinum, titanium, rhodium, palladium, osmium, iridium, rhenium, ruthenium, germanium, beryllium, gallium, indium, tellurium, mercury, bismuth, and combinations thereof.

9. The conductive trace according to claim 8 , further comprising a dielectric layer over the precious metal layer, the dielectric layer including one selected from the group consisting of porcelain, glass, polymers, and combinations thereof.

10. The conductive trace according to claim 9 , wherein:
the interface layer is present up to about 10% by volume,
the conductive layer is present from about 40 to about 90% by volume,
the redox control layer is present up to about 20% by volume,
the precious metal layer is present up to about 15% by volume, and
the dielectric layer is present up to about 15% by volume.

11. The conductive trace according to claim 1 , wherein one or more layers of the conductive trace includes an inorganic pigment selected from the group consisting of CuCr, CuCrMn, FeCrCo, TiO 2 , NiCrFe, FeCo, FeMn and combinations thereof.

12. A method of forming a conductive trace on a substrate comprising:
bonding an interface layer to a surface of a substrate, the interface layer being formed from an interface material,
forming a conductive layer from a conductive material on the interface layer, wherein the conductive layer has an exposed portion,
layering a redox control material on the conductive layer to thereby form a redox control layer covering the exposed portion of the conductive layer,
producing a metal layer in electrical contact with the conductive layer through one or more voids in the redox control layer, and
wherein the interface layer and the redox control layer prevent the conductive layer from being exposed to oxygen present in the environment.

13. The method according to claim 12 , wherein:
the substrate comprises one of i) glass or ceramic, ii) metal, or iii) polymer; and
if the substrate comprises i) glass or ceramic, then the interface material comprises borosilicate glass frit, if the substrate comprises ii) metal, then the interface material comprises a dielectric agent, and if the substrate comprises iii) polymer, then the interface material comprises a silane based adhesion promoter.

14. The method according to claim 12 , wherein the interface material comprises a silver migration control additive selected from the group consisting of silicon, iron, zinc, glass frits containing sulfur, and combinations thereof.

15. The method according to claim 12 , wherein the interface material comprises a dielectric material selected from the group consisting of borosilicate glass frit, silica, zirconia, alumina, titania based compounds, and combinations thereof.

16. The method according to claim 12 , wherein the conductive material comprises a conductive metal powder selected from the group consisting of copper, aluminum, nickel, tin, tungsten, zinc, iron, silver, steel, and combinations thereof.

17. The method according to claim 12 , wherein the redox control material comprises a redox control agent selected from the group consisting of carbon particles, oxygen getter material, and combinations thereof.

18. The method according to claim 12 , wherein the metal layer is a precious metal layer formed from a precious metal material including one selected from the group consisting of silver, gold, platinum, titanium, rhodium, palladium, osmium, iridium, rhenium, ruthenium, germanium, beryllium, gallium, indium, tellurium, mercury, bismuth, and combinations thereof.

19. The method according to claim 18 , further comprising generating a dielectric layer over the precious metal layer, wherein the dielectric layer is formed from a dielectric material comprising a dielectric agent selected from the group consisting of borosilicate glass frits, silica, zirconia, alumina, titania based compounds, and combinations thereof.

Assignees

• Ferro Corp

Inventors

• Sakoske George E
• Maitland Phil
• Speer Dietrich
• Walter Frank
• Blonski Robert P
• Sridharan Srinivasan

Classifications

• H05K1/115

  Via connections; Lands around holes or via connections (H05K1/112 takes precedence) · CPC title

• H05K1/092

  Dispersed materials, e.g. conductive pastes or inks · CPC title

• H05K3/1291 Primary

  Firing or sintering at relative high temperatures for patterns on inorganic boards, e.g. co-firing of circuits on green ceramic sheets · CPC title

• H05K2203/1126

  Firing, i.e. heating a powder or paste above the melting temperature of at least one of its constituents · CPC title

• H05K1/0306

  Inorganic insulating substrates, e.g. ceramic, glass · CPC title