Patent US2337305A successfully refreshed from Google Patents.
Patent US4769058A successfully refreshed from Google Patents.
US4769058A
Expired / Lapsed
US
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Method of making a smooth silica glass body
Assignee: GLT CORP A CORP OF
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Filing: 1987-09-14
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Granted: 1988-09-06
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Expires: 2007-09-14
Abstract
Abstract Silica glass having a substantially smooth, planar surface is formed by floating sintered silica glass on a molten metallic bath. The molten metallic bath is maintained at a sufficiently high temperature to heat-polish the sintered silica glass surface which is in thermal contact with the bath to form a substantially smooth, planar surface. A method for producing silica glass includes floating sintered silica glass on a molten metallic bath to provide the sintered glass with a substantially smooth surface. The resultant silica glass has many applications, but has particular utility for semiconductor substrates, integrated circuit masks, and other electronic applications.
Inventors
- 👤 Harold A. McMaster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:54
CPC Classifications
C; C03; C03B; C03B19/00; C03B19/12; C03B18/00; C03B18/02; C03B29/00; C03B29/02; C03B29/025; Y; Y10; Y10S; Y10S65/00; Y10S65/90
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
56 words
In a method for producing silica glass, of the type wherein a sol-gel is prepared, gelled to from a silica glass, and sintered to form a non-porous, roughly textured glass, the improvement comprising floating the sintered silica glass on a molten metallic bath to provide the sintered silica glass with a substantially smooth, heat-polished planar surface.
Claim 2
Dependent Claim
56 words
In a method for producing silica glass, of the type wherein a sol-gel is prepared, gelled to from a silica glass, and sintered to form a non-porous, roughly textured glass, the improvement comprising floating the sintered silica glass on a molten metallic bath to provide the sintered silica glass with a substantially smooth, heat-polished planar surface.
Claim 3
Dependent Claim
26 words
A method as in claim 1, wherein said floating the sintered silica glass is accomplished by floating the sintered silica glass on a molten tin bath.
Claim 4
Dependent Claim
37 words
A method as in claim 1, further comprising drying the gelled silica glass by slowly heating the glass to a temperature of about 100° C. to 300° C. under controlled conditions, whereby bubble formation is substantially prevented.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-06 | 1992-03-07 | 1992-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-06 | 1996-03-07 | 1996-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-06 | 2000-03-07 | 2000-09-06 | $7700.00 | Window Closed / Lapsed |