US4357202A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refractory oxide fabrication
Assignee: International Business Machines Corp
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Filing: 1981-06-12
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Granted: 1982-11-02
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Expires: 2001-06-12
Abstract
Abstract Refractory oxide materials, for example, Al 2 O 3 (sapphire) and Al 2 MgO 4 (spinel) can be shaped to precise dimensions by using a preformed member having a higher melting temperature than the oxide in the outline of the desired shape placed in contact with the refractory oxide and subjecting the combination to a temperature between 1500° C. and the melting temperature of the oxide in the presence of a forming gas atmosphere containing an inert gas and approximately 15% hydrogen. The refractory oxide is etched over the area of contact.
Inventors
- 👤 Richard F. Rutz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:24
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/53; C04B41/80; C04B41/91
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
127 words
In a process for etching a shape in a refractory oxide material taken from the group of Al 2 O 3 , SiO 2 , MgO and Al 2 MgO 4 , the improvement comprising: placing a preformed pattern of a material taken from the group of titanium, tantalum, zirconium and hafnium having a melting point higher than 1500° C. but less than the melting temperature of said preformed pattern material in contact with said refractory oxide material, and heating said refractory oxide and said preform pattern combination to a range of 1500° C. to the melting temperature of said preformed pattern in the presence of a neutral gas containing hydrogen for a time sufficient to effect an erosion of the surface of said refractory oxide material.
Claim 2
Dependent Claim
127 words
In a process for etching a shape in a refractory oxide material taken from the group of Al 2 O 3 , SiO 2 , MgO and Al 2 MgO 4 , the improvement comprising: placing a preformed pattern of a material taken from the group of titanium, tantalum, zirconium and hafnium having a melting point higher than 1500° C. but less than the melting temperature of said preformed pattern material in contact with said refractory oxide material, and heating said refractory oxide and said preform pattern combination to a range of 1500° C. to the melting temperature of said preformed pattern in the presence of a neutral gas containing hydrogen for a time sufficient to effect an erosion of the surface of said refractory oxide material.
Claim 3
Dependent Claim
28 words
The improvement of claim 1 including the additional step of further heating said material in the absence of hydrogen for a time sufficient to smooth the eroded portion.
Claim 4
Dependent Claim
18 words
The improvement of claim 1 wherein said placing of said preformed pattern is by deposition through a mask.
Claim 5
Dependent Claim
140 words
The process of etching in a direction predominantly perpendicular to the surface of a substrate of refractory oxide materials of the sapphire and spinel types comprising in combination the steps of: placing a preformed pattern of a material taken from the group of titanium, tantalum, zirconium and hafnium having a melting point higher than 1500° C. but less than the melting temperature of said preformed pattern material in contact with the surface of said refractory oxide material, heating said refractory oxide material and said preformed pattern material combination to the range of 1500° C. but less than the melting temperature of said preformed pattern material in the presence of a neutral gas containing hydrogen for a time sufficient to effect an erosion of the surface of said refractory oxide material under said preformed pattern, and removing said preformed pattern material.
Claim 6
Dependent Claim
140 words
The process of etching in a direction predominantly perpendicular to the surface of a substrate of refractory oxide materials of the sapphire and spinel types comprising in combination the steps of: placing a preformed pattern of a material taken from the group of titanium, tantalum, zirconium and hafnium having a melting point higher than 1500° C. but less than the melting temperature of said preformed pattern material in contact with the surface of said refractory oxide material, heating said refractory oxide material and said preformed pattern material combination to the range of 1500° C. but less than the melting temperature of said preformed pattern material in the presence of a neutral gas containing hydrogen for a time sufficient to effect an erosion of the surface of said refractory oxide material under said preformed pattern, and removing said preformed pattern material.
Claim 7
Dependent Claim
44 words
The improvement of claim 4 wherein said step of placing said preformed pattern is performed by deposition through a mask and said step of removal is by etching with an etch that acts on said preformed pattern but does not act on said substrate.
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) | 1985-11-01 | 1986-05-03 | 1986-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-01 | 1990-05-03 | 1990-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-01 | 1994-05-03 | 1994-11-02 | $7700.00 | Window Closed / Lapsed |