Thick film conductive inks for electronic devices

Patent metadata

Field	Value
Publication number	US-9351398-B2
Application number	US-201313857011-A
Country	US
Kind code	B2
Filing date	Apr 4, 2013
Priority date	Apr 4, 2013
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

Thick film conductive inks for electronic devices, methods for making electronic devices using thick film conductive inks, and electronic devices fabricated by such methods are provided herein. In one example, a thick film conductive ink includes an organic portion and an inorganic portion. The inorganic portion is dispersed in the organic portion to define a paste. The inorganic portion includes metallic copper powder, cupric oxide, and elemental boron. The thick film conductive ink includes substantially no glass.

First claim

What is claimed is:

1. A thick film conductive ink for an electronic device, the thick film conductive ink comprising:
an organic portion; and
an inorganic portion dispersed in the organic portion defining a paste, wherein the inorganic portion comprises metallic copper powder, cupric oxide, and elemental boron, and wherein the thick film conductive ink comprises substantially no glass, wherein the metallic copper powder comprises a first copper powder, a second copper powder, and/or a third copper powder, wherein the first copper powder has a first average surface area of from about 0.3 to about 0.8 m 2 /g, the second copper powder has a second average surface area of from about 0.8 to about 1.5 m 2 /g, and the third copper powder has a third average surface area of from about 1.5 to about 2.5 m 2 /g, and wherein the metallic copper powder comprises the first copper powder that has a median particle size of about 4.5 to about 10.5 μm.

2. The thick film conductive ink of claim 1 , wherein the inorganic portion comprises substantially no lead.

3. The thick film conductive ink of claim 1 , wherein the inorganic portion consists essentially of the metallic copper powder, cupric oxide, and elemental boron.

4. The thick film conductive ink of claim 1 , wherein the organic portion is present in an amount of from about 10 to about 30 wt. % of the thick film conductive ink.

5. The thick film conductive ink of claim 1 , wherein the inorganic portion is present in an amount of from about 70 to about 90 wt. % of the thick film conductive ink.

6. The thick film conductive ink of claim 1 , wherein the metallic copper powder is present in an amount of from about 50 to about 85 wt. % of the thick film conductive ink.

7. The thick film conductive ink of claim 1 , wherein cupric oxide is present in an amount of from about 3 to about 23 wt. % of the thick film conductive ink.

8. The thick film conductive ink of claim 1 , wherein elemental boron is present in an amount of from about 0.5 to about 5 wt. % of the thick film conductive ink.

9. The thick film conductive ink of claim 1 , wherein the organic portion comprises an organic liquid having a boiling point of from about 220 to about 300° C. at 1 atmosphere of pressure.

10. The thick film conductive ink of claim 1 , wherein the organic portion comprises 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate.

11. The thick film conductive ink of claim 10 , wherein 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate is present in an amount of from about 8 to about 25 wt. % of the thick film conductive ink.

12. The thick film conductive ink of claim 1 , wherein the organic portion comprises ethyl cellulose.

13. The thick film conductive ink of claim 12 , wherein ethyl cellulose is present in an amount of from about 0.5 to about 3 wt. of the thick film conductive ink.

14. The thick film conductive ink of claim 1 , wherein the organic portion comprises butyl diglyme.

15. The thick film conductive ink of claim 14 , wherein butyl diglyme is present in an amount of from about 1 to about 4 wt. % of the thick film conductive ink.

16. The thick film conductive ink of claim 1 , wherein the metallic copper powder has a median particle size of from about 0.01 to about 10.5 μm.

17. A method for making an electronic device, the method comprising the steps of:
depositing a thick film conductive ink overlying a substrate, wherein the thick film conductive ink comprises:
an organic portion; and
an inorganic portion dispersed in the organic portion defining a paste, wherein the inorganic portion comprises metallic copper powder, cupric oxide, and elemental boron, and wherein the thick film conductive ink comprises substantially no glass, wherein the metallic copper powder comprises a first copper powder, a second copper powder, and/or a third copper powder, wherein the first copper powder has a first average surface area of from about 0.3 to about 0.8 m 2 /g, the second copper powder has a second average surface area of from about 0.8 to about 1.5 m 2 /g, and the third copper powder has a third average surface area of from about 1.5 to about 2.5 m 2 /g, and wherein the metallic copper powder comprises the first copper powder that has a median particle size of about 4.5 to about 10.5 μm; and

firing the thick film conductive ink to form a conductor overlying the substrate.

18. The method of claim 17 , wherein depositing comprises depositing the thick film conductive ink in a single print to form a first conductor paste layer, and wherein firing comprises firing the first conductor paste layer to form the conductor having a single print fired thickness of from about 0.0254 to about 0.1524 mm.

19. An electronic device comprising:
a substrate; and
a conductor overlying the substrate and comprising fused/sintered metallic copper, cupric oxide, boron trioxide, and substantially no glass, wherein the metallic copper comprises a first copper powder, a second copper powder, and/or a third copper powder, wherein the first copper powder has a first average surface area of from about 0.3 to about 0.8 m 2 /g, the second copper powder has a second average surface area of from about 0.8 to about 1.5 m 2 /g, and the third copper powder has a third average surface area of from about 1.5 to about 2.5 m 2 /g, and wherein the metallic copper powder comprises the first copper powder that has a median particle size of about 4.5 to about 10.5 μm.

Assignees

• Gm Global Tech Operations Inc

Inventors

• Albaugh Lisa M
• Smith David A
• Guse Timothy J

Classifications

• Y10T428/31678

  Of metal · CPC title

• H05K3/1233

  Methods or means for supplying the conductive material and for forcing it through the screen or stencil · CPC title

• H05K3/1291

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

• C09D11/037

  characterised by the pigment · CPC title

• C09D11/52

  Electrically conductive inks · CPC title