Methods using silver compositions for micro-deposition direct writing silver conductor lines on photovoltaic wafers
View Patent ↗Embodiments of the invention relate to a silicon semiconductor device, and a conductive thick film composition for use in a solar cell device.
1. A method of manufacturing a semiconductor device comprising the steps of:
(a) providing a semiconductor substrate, one or more insulating films, and the thick film composition;
(b) applying the insulating film to the semiconductor substrate,
(c) applying the thick film composition to the insulating film on the semiconductor substrate, and
(d) firing the semiconductor, insulating film and thick film composition, wherein the thick film composition comprises:
(a) one or more conductive materials;
(b) one or more inorganic binders; and
(c) organic vehicle,
wherein 1 to 15% of the conductive materials are submicron particles.
2. The method of claim 1 , wherein the insulating film comprises one or more components selected from: titanium oxide, silicon nitride, SiNx:H, silicon oxide, and silicon oxide/titanium oxide.
3. The method of claim 1 , wherein 85 to 99 of the inorganic components have a d50 of 1.5 to 10 microns.
4. The method of claim 1 , wherein the one or more conductive materials comprise silver.
5. The method of claim 4 , wherein the submicron particles comprise silver.
6. The method of claim 5 , wherein the submicron particles further comprise ZnO and an inorganic binder.
7. The method of claim 1 , wherein the submicron particles have a d50 of 0.1 to 1 microns.
8. The method of claim 1 , wherein the submicron particles have a d50 of 0.1 to 0.6 microns.
9. The method of claim 1 , wherein the conductive materials have a bimodal size distribution.
10. The method of claim 9 wherein in said application step (c), said thick film composition is applied in a pattern comprising conductive fingers, and wherein after said firing step (d) said fired conductive fingers have a thickness in the range of 5 to 50 microns.
11. The method of claim 9 wherein in said application step (c), said thick film composition is applied in a pattern comprising conductive fingers, and wherein after said firing step (d) said fired conductive fingers have a width in the range of 20 to 75 microns.
12. The method of claim 1 , wherein the thick film composition further comprises one or more additives.
13. The method of claim 12 , wherein the one or more additives comprise components selected from the group consisting of: (a) a metal wherein said metal is selected from Zn, Pb, Bi, Gd, Ce, Zr, Ti, Mn, Sn, Ru, Co, Fe, Cu, and Cr; (b) a metal oxide of one or more of the metals selected from Zn, Pb, Bi, Gd, Ce, Zr, Ti, Mn, Sn, Ru, Co, Fe, Cu and Cr; (c) any compounds that can generate the metal oxides of (b) upon firing; and (d) mixtures thereof.
14. The method of claim 13 , wherein the one or more inorganic additives comprises ZnO.
15. The method of claim 1 , wherein the one or more inorganic binders comprise glass frit.
16. The method of claim 1 , wherein the inorganic components are 70 to 95 wt % of the total composition.