Thick-film paste containing lead-tungsten-based oxide and its use in the manufacture of semiconductor devices
AssigneeE. I. Du Pont de Nemours and Company
InventorsKATHERINE ANNE BERNARDINA, BRIAN J. LAUGHLIN, PAUL DOUGLAS VERNOOY
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Abstract
The present invention provides a thick-film paste for printing the front side of a solar cell device having one or more insulating layers and a method for doing so. The thick-film paste comprises a source of an electrically conductive metal and a lead-tungsten-based oxide dispersed in an organic medium. The invention also provides a semiconductor device comprising an electrode formed from the thick-film paste.
Claims24
A thick-film paste composition comprising:
- a) 80-99.5 wt % of a source of electrically conductive metal;
- b) 0.5 to 20 wt % of a vanadium-free, tellurium-free lead-tungsten-based oxide;
- and
- c) an organic medium;
- wherein said source of electrically conductive metal and said vanadium-free, tellurium-free lead-tungsten-based oxide are dispersed in said organic medium and wherein the above wt % are based on the total weight of said source of electrically conductive metal and said vanadium-free, tellurium-free lead-tungsten-based oxide, said vanadium-free, tellurium-free lead-tungsten-based oxide comprising 55-88 wt % PbO, 12-25 wt % WO3 and 0-20 wt % of one or more additional oxides selected from the group consisting of B2O3, Bi2O3, SiO2, Al2O3, Li2O, K2O, Rb2O, Na2O, Cs2O and MoO3, wherein the wt % of PbO, WO3 and the one or more additional oxides are based on the total weight of said vanadium-free tellurium-free lead-tungsten-based oxide.
A vanadium-free, tellurium free lead-tungsten-based oxide comprising 55-88 wt % PbO, 12-25 wt % WO3 and 0-20 wt % of one or more additional oxides selected from the group consisting of B2O3, Bi2O3, SiO2, Al2O3, Li2O, K2O, Rb2O, Na2O, Cs2O and MoO3, wherein the wt % of PbO, WO3 and the one or more additional oxides are based on the total weight of said vanadium-free tellurium-free lead-tungsten-based oxide.
A process comprising:
- (a) providing an article comprising one or more insulating films disposed onto at least one surface of a semiconductor substrate;
- (b) applying a thick-film paste composition onto the one or more insulating films to form a layered structure, the thick-film paste composition comprising:
- (i) 80-99.5 wt % of a source of electrically conductive metal;
- (ii) 0.5 to 20 wt % of a vanadium-free, tellurium-free lead-tungsten-based oxide;
- and
- (iii) an organic medium;
- wherein said source of electrically conductive metal and said vanadium-free, tellurium-free lead-tungsten-based oxide are dispersed in said organic medium and wherein the above wt % are based on the total weight of said source of electrically conductive metal and said vanadium-free, tellurium-free lead-tungsten-based oxide, said vanadium-free, tellurium-free lead-tungsten-based oxide comprising 55-88 wt % PbO, 12-25 wt % WO3 and 0-20 wt % of one or more additional oxides selected from the group consisting of B2O3, Bi2O3, SiO2, Al2O3, Li2O, K2O, Rb2O, Na2O, Cs2O and MoO3, wherein the wt % of PbO, WO3 and the one or more additional oxides are based on the total weight of said vanadium-free tellurium-free lead-tungsten-based oxide;
- and
- (c) firing said semiconductor substrate, said one or more insulating films, and said thick-film paste wherein said organic medium of said thick film paste is volatilized, thereby forming an electrode in contact with said one or more insulating layers and in electrical contact with said semiconductor substrate.
A semiconductor device comprising an electrode formed from a thick-film paste composition comprising:
- a) 80-99.5 wt % of a source of electrically conductive metal;
- b) 0.5 to 20 wt % of a vanadium-free, tellurium-free lead-tungsten-based oxide;
- and
- c) an organic medium;
- wherein said source of electrically conductive metal and said vanadium-free, tellurium-free lead-tungsten-based oxide are dispersed in said organic medium and wherein the above wt % are based on the total weight of said source of electrically conductive metal and said vanadium-free, tellurium-free lead-tungsten-based oxide, said vanadium-free, tellurium-free lead-tungsten-based oxide comprising 55-88 wt % PbO, 12-25 wt % WO3 and 0-20 wt % of one or more additional oxides selected from the group consisting of B2O3, Bi2O3, SiO2, Al2O3, Li2O, K2O, Rb2O, Na2O, Cs2O and MoO3, wherein the wt % of PbO, WO3 and the one or more additional oxides are based on the total weight of said vanadium-free tellurium-free lead-tungsten-based oxide.
Dependencies are inferred from the claim text.