Thick film copper conductor inks
AssigneeRCA Corporation
InventorsAshok N. Prabhu, Kenneth W. Hang, Edward J. Conlon
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Abstract
Improved copper conductor inks useful in fabricating multilevel circuits are provided. The inks comprise copper powder, a novel zinc-aluminum-lead-borosilicate glass frit, bismuth oxide and a suitable organic vehicle. The inks are advantageous in that the films formed therefrom are oxidation resistant and have a reduced tendency for flux components to leach into adjacent dielectric films.
Claims6
A copper conductor ink comprising, on a weight basis:
- (a) from about 65 to about 85 percent of copper powder;
- (b) from about 5 to about 15 percent of a glass frit comprising, on a weight basis:
- from about 52 to 53 percent of zinc oxide;
- from about 25 to 26 percent of boron trioxide;
- from about 6 to 8 percent of silicon dioxide;
- from about 7 to 12 percent of lead oxide;
- from about 2 to 5 percent of aluminum oxide;
- from 0 to about 2 percent of antimony trioxide;
- and
- from 0 to about 1 percent of cerium oxide;
- (c) from about 1 to about 4 percent of bismuth oxide;
- and
- (d) from about 5 to about 25 percent of a suitable organic vehicle.
In a multilayer, copper-based, integrated circuit structure comprising a suitable substrate having thereon at least two patterned layers of a copper conductor, said layers being separated by a dielectric layer having vias therein, said vias being filled with copper to contact said conductor layers, the improvement wherein said copper conductor layers comprise, on a weight basis:
- (a) from about 70 to about 94 percent of copper powder;
- (b) from about 5 to about 18 percent of a glass frit comprising, on a weight basis:
- from about 52 to 53 percent of zinc oxide;
- from about 25 to 26 percent of boron trioxide;
- from about 6 to 8 percent of silicon dioxide;
- from about 7 to 12 percent of lead oxide;
- from about 2 to 5 percent of aluminum oxide;
- from 0 to about 2 percent of antimony trioxide;
- and
- from 0 to about 1 percent of cerium oxide;
- and
- (c) from about 1 to about 4 percent of bismuth oxide.
Dependencies are inferred from the claim text.