Conductive paste and ceramic substrate manufactured using the same

Patent metadata

Field	Value
Publication number	US-9585250-B2
Application number	US-201314433153-A
Country	US
Kind code	B2
Filing date	Oct 2, 2013
Priority date	Oct 3, 2012
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

[Problem to be solved] The present invention provides a conductive paste for constrained firing and a ceramic substrate manufactured with the conductive paste, the conductive paste having an excellent plating resistance and a good adherence against a ceramic substrate and a plated film even after plating treatment, wherein a constraining layer after firing can be easily removed without remaining on a surface conductor in a case where co-firing is performed.
[Solution] Provided is a conductive paste comprising 60 to 95 mass % of an Ag powder as the content in a paste composition, 0.5 to 5 mass % of a borosilicate based glass powder relative to the Ag powder, the remainder being a platinum group metal additive and an organic vehicle, wherein the platinum group metal additive contains at least two metals of Ru and Rh, and the content of Ru and the content of Rh in the platinum group metal additive are 0.05 to 5 mass % of Ru and 0.001 to 0.1 mass % of Rh respectively in terms of metal components relative to the mass of the Ag powder

First claim

The invention claimed is:

1. A conductive paste to be printed on a low-temperature fired ceramic green sheet layered product for forming a surface conductor by constrained firing, the conductive paste comprising 60 to 95 mass % of an Ag powder as the content in a paste composition, 0.5 to 5 mass % of a borosilicate based glass powder relative to the Ag powder, the remainder being a platinum group metal additive and an organic vehicle,
wherein the platinum group metal additive contains at least two metals of Ru and Rh, and the content of Ru and the content of Rh in the platinum group metal additive are 0.05 to 5 mass % of Ru and 0.001 to 0.1 mass % of Rh respectively in terms of metal components relative to the mass of the Ag powder.

2. The conductive paste according to claim 1 , wherein the glass powder has a softening point of 710 to 890° C.

3. The conductive paste according to claim 1 or 2 , wherein the Ag powder comprises two Ag powders having different mean secondary particle diameters before kneaded with other paste composition components.

4. The conductive paste according to claim 3 , wherein 20 mass % or more is an Ag powder having a mean secondary particle diameter of 20 to 60 μm relative to the mass of the Ag powder, the remainder being an Ag powder having a mean secondary particle diameter of 3 to 10 μm.

5. A ceramic substrate obtained by constrained-firing a low-temperature fired ceramic green sheet layered product on which the conductive paste according to any one of claims 1 to 4 is printed as a surface conductor.

Assignees

• Tdk Corp
• Tanaka Precious Metal Ind

Inventors

• Sato Minoru
• Kawata Tomoaki
• Hirano Masahiro
• Onozumi Shigekazu

Classifications

• C04B35/10

  based on aluminium oxide · CPC title

• Y10T428/24909

  Free metal or mineral containing · CPC title

• C04B2235/6567

  Treatment time · CPC title

• H05K1/092 Primary

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

• C04B2237/562

  made of alumina or aluminates · CPC title