Method for forming a structure

• US 7,790,508 B2
• Filed: 03/08/2005
• Issued: 09/07/2010
• Est. Priority Date: 03/09/2004
• Status: Active Grant

• Current Assignee: Schott Solar AG (Carl-Zeiss-Stiftung)
• Original Assignee: Schott Solar AG (Carl-Zeiss-Stiftung)
• Inventors: Schwirtlich, Ingo, Von Campe, Hilmar
• Primary Examiner(s): Garber; Charles D
• Assistant Examiner(s): SENE, PAPE A
• Application Number:
  US10/562,851
• Publication Number:
  US 20080146016A1
• Time in Patent Office: 2,009 Days
• Field of Search: 438/119
• US Class Current: 438/119
• CPC Class Codes: H01L 31/022425 for solar cells
• CPC Class Codes: H05K 1/095 for polymer thick films, i.e. having a permanent organic polymeric binder
• CPC Class Codes: H05K 3/4007 Surface contacts, e.g. bumps H05K3/4092 takes precedence; deposition of finish layers on pads H05K3/24; forming solder bumps H05K3/3457
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

Method for constructing a line or dotted structure on a support, especially for constructing strip-like electrically conducting contacts on a semiconductor component such as a solar cell, by applying an electrically conducting paste-like substance containing a solvent adhering to a support and subsequent hardening of the substance. After the substance is applied to the support, a medium containing a polar molecule is applied on the support and/or the substance, through which the solvent contained in the substance is extracted.

Claims

1. Method for constructing an electrically conducting linear and/or punctiform structure on a support, comprising the steps of:

applying to a portion of the support a flowable, electrically conductive paste-like substance containing a solvent in a linear or punctiform arrangement;

after said applying, contacting the substance with a medium containing a polar molecule, causing thereby the solvent contained in the substance to be extracted therefrom in an edge region, resulting in a hardening and stabilizing of the substance in the edge region.

2. Method according to claim 1, wherein the support comprises a semiconductor solar cell.

3. Method according to claim 1, wherein the polar medium comprises water or a mixture of water and at least one surfactant selected from the group consisting of anionic surfactants, cationic surfactants, non-ionic surfactants, and amphoteric surfactants.

4. Method according to claim 3, wherein the surfactants are selected from the group consisting of soap, fatty alcohol sulfates, alkyl benzene sulfonates, non-carbonic acid ester of polyalcohols.

5. Method according to claim 1, wherein the paste-like substance is applied to the support by at least one of screen printing, tampon printing, finger writing techniques or spraying techniques.

6. Method according to claim 1, wherein the polar medium is applied to the substance from about 0.1 to about 600 seconds after applying the substance to the support.

7. Method according to claim 6, wherein the polar medium is applied to the substance from about 1 to about 60 seconds after applying the substance to the support.

8. Method according to claim 1, wherein the substance is applied to the support in a circular cross section with a diameter d, where about 15 μ

m ≦

d≦

about 300 μ

m.

9. Method according to claim 8, wherein d is about 80 μ

m.

10. Method according to claim 1, wherein the substance includes water soluble and water insoluble solvents.

11. Method according to claim 1, wherein the substance is applied to the substrate such that after hardening, the substance has a height to breadth ratio a, where 0.1≦

a≦

1.0.

12. Method according to claim 11, where a is about 0.3.

13. Method according to claim 1, wherein the support is a silicon substrate with a surface layer comprising at least one of silicon oxide and silicon nitride.

14. Method according to claim 1, wherein a concentration gradient between the polar medium and the substance is set with respect to the solvents present in the substance, such that the solvent of the substance is extracted into the medium.

15. Method for constructing an electrically conducting linear and/or punctiform structure on a support, comprising the steps of:

applying to a portion of the support a flowable, electrically conductive paste-like substance containing a solvent in a linear or punctiform arrangement;

after said applying, contacting the support with a medium containing a polar molecule, with forces of adhesion between the medium and the support being greater than forces of adhesion between the substance and the support,

said contacting thereby substantially preventing flowing of the substance along the support and detachment of the substance from the support.

16. Method according to claim 15, wherein the polar medium is applied on the support in the form of a liquid or a foam in the region of the applied paste-like substance.

17. Method according to claim 16, wherein the polar medium comprises water or a mixture of water and at least one surfactant selected from the group consisting of anionic surfactants, cationic surfactants, non-ionic surfactants, and amphoteric surfactants.

18. Method according to claim 17, wherein the surfactants are selected from the group consisting of soap, fatty alcohol sulfates, alkyl benzene sulfonates, non-carbonic acid ester of polyalcohols.

19. Method according to claim 15, wherein the paste-like substance is applied to the support by at least one of screen printing, tampon printing, finger writing techniques or spraying techniques.

20. Method according to claim 15, wherein the polar medium is applied to the substance from about 0.1 to about 600 seconds after applying the substance to the support.

21. Method according to claim 20, wherein the polar medium is applied to the substance from about 1 to about 60 seconds after applying the substance to the support.

22. Method according to claim 15, wherein the substance is applied to the support in a circular cross section with a diameter d, where about 15 μ

m≦

d≦

about 300 μ

m.

23. Method according to claim 22, wherein d is about 80 μ

m.

24. Method according to claim 15, wherein the substance includes water soluble and water insoluble solvents.

25. Method according to claim 15, wherein the substance is applied to the substrate such that after hardening, the substance has a height to breadth ratio a, where 0.1≦

a≦

1.0.

26. Method according to claim 25, where a is about 0.3.

27. Method according to claim 15, wherein the support comprises a semiconductor solar cell.

28. Method according to claim 15, wherein the support is a silicon substrate with a surface layer comprising at least one of silicon oxide and silicon nitride.