US4497675A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of substrates from carbon-coated silicon dioxide fabric that can be used for large-surface silicon bodies
Assignee: Siemens AG
•
Filing: 1983-11-25
•
Granted: 1985-02-05
•
Expires: 2003-11-25
Abstract
Abstract The invention concerns a process for the manufacture of substrates from carbon-coated SiO 2 fabric that can be used for large-surface silicon bodies, in which mineral materials or waste containing SiO 2 are used as starting materials and a mixture of Al 2 O 3 and oxides of the alkaline and/or alkaline earth metals is used as a flux for the transformation into the glass phase. The glass fibers made from the homogenous glass melt are processed into a glass fabric, which is then subjected to an acid leaching process and coated with carbon. The process is used for the low-cost production of substrates for silicon bodies that are manufactured according to the strip-coating process for use in solar cells.
Inventors
- 👤 Hubert Aulich
- 👤 Karl-Heinz Eisenrith
- 👤 Hans-Peter Urbach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:44
CPC Classifications
C; C03; C03C; C03C13/00; C03C13/005; C03C25/00; C03C25/10; C03C25/42; C03C25/44; C03C25/66; C03C25/68; H; H10; H10F; H10F71/00; H10F71/121; H10F77/00; H10F77/10; H10F77/16; H10F77/169; H10F77/1692; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/547; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
141 words
A process for the manufacture of substrates from carbon-coated silicon dioxide fabric that can be used for large-surface silicon bodies, for the manufacture of solar cells according to a strip-coating process, the improvement comprising the steps of: (a) using mineral or waste materials containg SiO 2 as starting materials; (b) transforming said starting materials into a glass phase with a mixture of materials selected from the group consisting of aluminum oxide (Al 2 O 3 ), carbonates, and oxides of the elements in the alkaline and alkaline earth metal groups; (c) producing a homogenous glass melt at 1100° to 1500° C.; (d) transforming said glass melt into a glass fiber stage; (e) processing said glass fiber into a glass fabric; (f) subjecting said glass fabric to a leaching process in hot mineral acid; and (g) coating said glass fabric with carbon.
Claim 2
Dependent Claim
141 words
A process for the manufacture of substrates from carbon-coated silicon dioxide fabric that can be used for large-surface silicon bodies, for the manufacture of solar cells according to a strip-coating process, the improvement comprising the steps of: (a) using mineral or waste materials containg SiO 2 as starting materials; (b) transforming said starting materials into a glass phase with a mixture of materials selected from the group consisting of aluminum oxide (Al 2 O 3 ), carbonates, and oxides of the elements in the alkaline and alkaline earth metal groups; (c) producing a homogenous glass melt at 1100° to 1500° C.; (d) transforming said glass melt into a glass fiber stage; (e) processing said glass fiber into a glass fabric; (f) subjecting said glass fabric to a leaching process in hot mineral acid; and (g) coating said glass fabric with carbon.
Claim 3
Dependent Claim
26 words
The process according to claim 1, wherein 3 n-6 n hydrochloric acid heated to 100° C. in an extractor is used as said hot mineral acid.
Claim 4
Dependent Claim
43 words
The process according to claim 1, further comprising adding boron oxide (B 2 O 3 ) to said mixture of materials selected from the group consisting of aluminum oxide, carbonates, and oxides of the elements in the alkaline and alkaline earth metal groups.
Claim 5
Dependent Claim
37 words
The process according to claim 1, wherein said mineral starting materials comprise materials selected from the group consisting of silica sand obtained by mining, volcanic rocks, basalt, and olivines (silicates with beryllium, magnesium, zinc, iron, and manganese).
Claim 6
Dependent Claim
22 words
The process according to claim 4, wherein said volcanic rocks are feldspar (K.AlSi 3 O 8 , Na.AlSi 3 O 8 ).
Claim 7
Dependent Claim
17 words
The process according to claim 1, wherein said mineral starting material comprises quartz waste and glass waste.
Claim 8
Dependent Claim
13 words
The process according to claim 6, wherein said glass waste comprises glass shards.
Claim 9
Dependent Claim
29 words
The process according to claim 1, further comprising the addition of oxides of sodium, potassium, magnesium, and calcium for the transformation of said starting materials into said glass phase.
Claim 10
Dependent Claim
42 words
The process according to claim 8, wherein the content of Al 2 O 3 and CaO in said glass melt does not exceed 20% by weight and the content of alkaline and alkaline earth metal oxides does not exceed 10% by weight.
Claim 11
Dependent Claim
29 words
The process according to claim 1, further comprising the addition of carbonates of sodium, potassium, magnesium, and calcium for the transformation of said starting materials into said glass phase.
Claim 12
Dependent Claim
35 words
The process according to claim 1, wherein dolomite (CaCO 3 , MgCO 3 ) which contains potassium, calcium, and magnesium in the oxide form, is used for transforming said starting materials into said glass phase.
Claim 13
Dependent Claim
34 words
The process according to claim 1, wherein the step of transforming said glass melt into a glass fiber stage is accomplished with a multi-nozzle crucible, through which said glass fibers are drawn perpendicularly downward.
Claim 14
Dependent Claim
17 words
The process of claim 12, wherein said glass fibers have a diameter substantially equal to 10 microns.
Claim 15
Dependent Claim
28 words
The process according to claim 1, wherein the step of subjecting said glass fabric to hot mineral acid further comprises subsequent treating with a weak caustic soda solution.
Claim 16
Dependent Claim
20 words
The process according to claim 14, wherein the step of subjecting said glass fabric to hot mineral acid is repeated.
Claim 17
Dependent Claim
22 words
The process according to claim 1, wherein the step of coating said glass fabric with said carbon is accomplished with cathode sputtering.
Claim 18
Dependent Claim
57 words
The process according to claim 1, wherein a composition of the glass is used so that following subjecting said glass fabric to a leaching process, a sufficient amount of boron remains in said silicon dioxide whereby, when subsequently coating said fabric with molten silicon, primary doping of said silicon body is accomplished by diffusion from said fabric.
Claim 19
Dependent Claim
58 words
The process according to claim 1, wherein a composition of the glass is used so that following subjecting said glass fabric to a leaching process, a sufficient amount of phosphorous remains in said silicon dioxide fabric whereby, when subsequently coating said fabric with molten silicon, primary doping of said silicon body is accomplished by diffusion from said fabric.
Claim 20
Dependent Claim
74 words
The process according to claim 1, wherein a composition of the glass is used so that, following subjecting said glass to a leaching process, a sufficient amount of boron remains in said silicon dioxide fabric, whereby when said fabric is coated with molten silicon, a p + layer is formed in the silicon body by diffusion from the fabric so that said layer can be used as a back-surface contact for said solar cell.
Claim 21
Dependent Claim
73 words
The process according to claim 1, wherein a composition of the glass is used so that, following subjecting said glass to a leaching process, a sufficient amount of phosphorous remains in said silicon dioxide fabric, whereby when said fabric is coated with molten silicon, an n+ layer is formed in the silicon body by diffusion from the fabric so that said layer can be used as a back-surface contact for said solar cell.
References Cited (Backward Citations)
US3356563A
Cited
US3914856A
Cited
US4152535A
Cited
US4171991A
Cited
DE3010557A1
Cited
US4370288A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-05 | 1988-08-06 | 1989-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-05 | 1992-08-06 | 1993-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-05 | 1996-08-06 | 1997-02-05 | $7700.00 | Window Closed / Lapsed |