US4470856A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-compensating hydrostatic flattening of semiconductor substrates
Assignee: Victor Company of Japan Ltd
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Filing: 1983-02-07
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Granted: 1984-09-11
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Expires: 2003-02-07
Abstract
Abstract A semiconductive substrate, such as a silicon wafer, is mounted on a baseplate for inclusion in an optical device such as a liquid crystal light valve. An optical flat presses the top surface of silicon wafer toward the baseplate and against an O-ring seal surrounding a fluid adhesive. The fluid adhesive hydrostatically distributes the force of compression to guarantee optical flatness and self-compensation for the amount fluid adhesive surrounded by the O-ring. The optical flatness of the semiconductor substrate is limited only by the flatness of the optical flat against which it is compressed. Parallel alignment of the optical flat, the substrate and the baseplate is achieved by reflecting a laser beam through the semiconductive substrate and observing the interference fringes therein, while adjusting the relative alignment so as to maximize the distance between fringes.
Inventors
- 👤 Michael J. Little
- 👤 Roger H. Brown
- 👤 Uzi Efron
- 👤 Clarence P. Hoberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:07
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/12; G; G01; G01B; G01B11/00; G01B11/26; H10F; H10F77/00; H10F77/50
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
109 words
A method for mounting one surface of a semiconductor member on a baseplate and flattening the other surface of said semiconductor member to an optically flat finish, comprising: placing a flexible ring seal on the top surface of said baseplate; placing a fluid adhesive on said top surface of said baseplate so that it is surrounded by said flexible ring seal; placing said semiconductor substrate over said flexible ring seal; pressing an optically flat surface over said semiconductive substrate so as to compress and displace said ring seal and said fluid adhesive; and holding said optically flat surface in place after said pressing step until said adhesive has solidified.
Claim 2
Independent Claim
109 words
A method for mounting one surface of a semiconductor member on a baseplate and flattening the other surface of said semiconductor member to an optically flat finish, comprising: placing a flexible ring seal on the top surface of said baseplate; placing a fluid adhesive on said top surface of said baseplate so that it is surrounded by said flexible ring seal; placing said semiconductor substrate over said flexible ring seal; pressing an optically flat surface over said semiconductive substrate so as to compress and displace said ring seal and said fluid adhesive; and holding said optically flat surface in place after said pressing step until said adhesive has solidified.
Claim 3
Dependent Claim
87 words
The method of claim 1 wherein said optically flat surface has an aperture, said method further comprising: directing a laser beam through said aperture so that said beam reflects from the top and bottom surfaces of said semiconductive substrate; observing interference fringes from the reflected beam at an image plane; and adjusting the relative alignment between said baseplate and said optically flat surface so as to maximize first the straightness of the interference fringes and second the distance between said interference fringes observed at said image plane.
Claim 4
Independent Claim
96 words
An apparatus for mounting and flattening a semiconductive substrate which may be either a wafer or a chip, on the top surface of a baseplate, comprising: a flexible ring seal disposed on said baseplate top surface; a fluid adhesive surrounded by said ring seal; a semiconductive substrate disposed over said ring seal and said fluid adhesive; a top plate having an optically flat bottom surface; means for pressing said top plate and said bottom baseplate together toward another, including means for adjusting the relative parallel alignment between said top optical flat and said bottom base plate.
Claim 5
Independent Claim
96 words
An apparatus for mounting and flattening a semiconductive substrate which may be either a wafer or a chip, on the top surface of a baseplate, comprising: a flexible ring seal disposed on said baseplate top surface; a fluid adhesive surrounded by said ring seal; a semiconductive substrate disposed over said ring seal and said fluid adhesive; a top plate having an optically flat bottom surface; means for pressing said top plate and said bottom baseplate together toward another, including means for adjusting the relative parallel alignment between said top optical flat and said bottom base plate.
Claim 6
Dependent Claim
30 words
The apparatus of claim 3 further comprising means for reflecting a coherent beam from said bottom and top surfaces of said semiconductive substrate and permitting observation of interference fringes therefrom.
Claim 7
Dependent Claim
13 words
The apparatus of claim 3 wherein said baseplate top surface is optically flat.
References Cited (Backward Citations)
US3229224A
Cited
US3510374A
Cited
US3573455A
Cited
US3802065A
Cited
US3843401A
Cited
US4156963A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-09-11 | 1988-03-12 | 1988-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-11 | 1992-03-12 | 1992-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-11 | 1996-03-12 | 1996-09-11 | $7700.00 | Window Closed / Lapsed |