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US3424532A
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Angle-lap techniques for measuring layer thicknesses
Assignee: AT&T Inc
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Filing: 1964-12-29
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Granted: 1969-01-28
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Expires: 1984-12-29
Abstract
No abstract record available.
Inventors
- 👤 Thomas H Briggs
- 👤 Richard H Dudley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:57
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/02; G01B11/06; G01B11/0616; G01B11/0675
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
170 words
A METHOD FOR MEASURING THIN LAYERS COMPRISING THE STEPS OF: CUTTING THE LAYER AT THE SMALL BEVEL ANGLE WITH RESPECT TO A HORIZONTAL REFERENCE SURFACE OF THE LAYER TO EXPOS A SURFACE THEREOF; STAINING THE EXPOSED BEVELED SURFACE; PHOTOGRAPHING FROM A FIRST LOCATION THE BEVELED SURFACE; LOCATING A FLAT PARTIALLY TRANSPARENT SURFACE OVER THE EXPOSED LAYER SURFACE SUCH THAT THE PARITALLY TRANSPARENT SURFACE AND THE LAYER SURFACE DEFINE AN ANGLE SUBSTANTIALLY EQUAL TO THE BEVEL ANGLE; REFLECTING SUBSTANTIALLY MONOCHROMATIC LIGHT FROM THE BEVELED SURFACE AND FROM THE FLAT PARTIALLY TRANSPARENT SURFACE TO ESTABLISH INTERFERENCE FRINGES; PHOTOGRAPHING FROM SUBSTANTIALLY THE FIRST LOCATION THE INTERFERENCE FRINGES; SCANNING THE TWO PHOTOGRAPHS SEPARATELY WITH A SCANNING DENSITOMETER AND RECORDING ON SEPARATE GRAPHS VARIATIONS WITH DISTANCE OF PHOTOGRAPHIC DENSITY ON THE PHOTOGRAPHS; DETERMINING FROM THE GRAPHS THE HORIZONTAL DISTANCE LN'' INCLUDED BY A NUMBER N OF ORDERS OF INTERFERENCE DEFINED BY SAID INTERFERING FRINGES, AND THE HORIZONTAL WIDTH B'' OF THE EXPOSED SURFACE; AND COMPUTING THE THICKNESS OF SAID LAYER IN ACCORDANCE WITH THE RELATIONSHIP
Claim 2
Independent Claim
170 words
A METHOD FOR MEASURING THIN LAYERS COMPRISING THE STEPS OF: CUTTING THE LAYER AT THE SMALL BEVEL ANGLE WITH RESPECT TO A HORIZONTAL REFERENCE SURFACE OF THE LAYER TO EXPOS A SURFACE THEREOF; STAINING THE EXPOSED BEVELED SURFACE; PHOTOGRAPHING FROM A FIRST LOCATION THE BEVELED SURFACE; LOCATING A FLAT PARTIALLY TRANSPARENT SURFACE OVER THE EXPOSED LAYER SURFACE SUCH THAT THE PARITALLY TRANSPARENT SURFACE AND THE LAYER SURFACE DEFINE AN ANGLE SUBSTANTIALLY EQUAL TO THE BEVEL ANGLE; REFLECTING SUBSTANTIALLY MONOCHROMATIC LIGHT FROM THE BEVELED SURFACE AND FROM THE FLAT PARTIALLY TRANSPARENT SURFACE TO ESTABLISH INTERFERENCE FRINGES; PHOTOGRAPHING FROM SUBSTANTIALLY THE FIRST LOCATION THE INTERFERENCE FRINGES; SCANNING THE TWO PHOTOGRAPHS SEPARATELY WITH A SCANNING DENSITOMETER AND RECORDING ON SEPARATE GRAPHS VARIATIONS WITH DISTANCE OF PHOTOGRAPHIC DENSITY ON THE PHOTOGRAPHS; DETERMINING FROM THE GRAPHS THE HORIZONTAL DISTANCE LN'' INCLUDED BY A NUMBER N OF ORDERS OF INTERFERENCE DEFINED BY SAID INTERFERING FRINGES, AND THE HORIZONTAL WIDTH B'' OF THE EXPOSED SURFACE; AND COMPUTING THE THICKNESS OF SAID LAYER IN ACCORDANCE WITH THE RELATIONSHIP
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-01-28 | 1972-07-29 | 1973-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-01-28 | 1976-07-29 | 1977-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-01-28 | 1980-07-29 | 1981-01-28 | $7700.00 | Window Closed / Lapsed |