Patent US4244348A successfully refreshed from Google Patents.
US4244348A
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Process for cleaving crystalline materials
Assignee: Siemens Solar Industries LP
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Filing: 1979-09-10
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Granted: 1981-01-13
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Expires: 1999-09-10
Abstract
Abstract A process for cleaving boules of single crystal materials such as silicon or germanium into thin wafers. The process comprises creating an inward-directed radial stress concentration completely around a boule which intersects its crystallographic plane of minimum bond strength; and subsequently, triggering the cleavage of a thin wafer from the boule via a shock wave applied normal to its crystallographic plane of minimum bond strength.
Inventors
- 👤 Donald F. Wilkes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:30
CPC Classifications
B; B28; B28D; B28D5/00; Y; Y10; Y10T; Y10T225/00; Y10T225/10; Y10T225/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
65 words
A process for cleaving a thin wafer from a boule of single crystal material comprising the steps of a. creating an inward directed radial stress concentration 360° around said boule, which intersects its crystallographic plane of minimum bond strength, and b. triggering said cleavage of said boule via a shock wave applied normal to said plane whereby said thin wafer is cleaved from said boule.
Claim 2
Dependent Claim
65 words
A process for cleaving a thin wafer from a boule of single crystal material comprising the steps of a. creating an inward directed radial stress concentration 360° around said boule, which intersects its crystallographic plane of minimum bond strength, and b. triggering said cleavage of said boule via a shock wave applied normal to said plane whereby said thin wafer is cleaved from said boule.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein said stress concentration is created uniformly.
Claim 4
Dependent Claim
21 words
The process of claim 1 wherein said triggering wave is created by striking said boule with a high modulus, hard substance.
Claim 5
Dependent Claim
14 words
The process of claim 1 wherein said triggering wave is an axially-induced shock wave.
Claim 6
Dependent Claim
11 words
The process of claim 4 wherein said shock wave is planar.
Claim 7
Dependent Claim
11 words
The process of claim 1 wherein said crystal material is silicon.
Claim 8
Dependent Claim
11 words
The process of claim 1 wherein said crystal material is germanium.
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) | 1984-01-13 | 1984-07-14 | 1985-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-13 | 1988-07-14 | 1989-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-13 | 1992-07-14 | 1993-01-13 | $7700.00 | Window Closed / Lapsed |