US5567199A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Workpiece holder for rotary grinding machines for grinding semiconductor wafers, and method of positioning the workpiece holder
Assignee: Siltronic AG
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Filing: 1994-09-21
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Granted: 1996-10-22
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Expires: 2014-09-21
Abstract
Abstract A workpiece holder for rotary grinding machines for grinding semiconductorafers has a rotatable work surface which points toward a rotating grinding tool and on which the semiconductor wafer to be machined is laid, and has piezoelectric elements on which the workpiece holder is axially supported. The piezoelectric elements can be operated independently of one another and, when operated, undergo a change in their linear dimension, an operated piezoelectric element axially raising or lowering the workpiece holder at the point at which it supports the workpiece holder. There is also a method for positioning the workpiece holder.
Inventors
- 👤 Anton Huber
- 👤 Robert Weiss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:21
CPC Classifications
H; H10; H10P; H10P50/00; H10P72/00; H10P72/70; H10P72/74; B; B23; B23Q; B23Q1/00; B23Q1/25; B23Q1/26; B23Q1/34; B24; B24B; B24B41/00; B24B41/06; B24B7/00; B24B7/10; B24B7/16; B24B7/20; B24B7/22
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
122 words
A workpiece holder for a rotary grinding machine having a rotating grinding tool for grinding semiconductor wafers, said workpiece holder having a periphery and comprising a rotatable work surface which points toward the rotating grinding tool and on said surface the semiconductor wafer to be machined is laid; piezoelectric elements on which the workpiece holder is axially supported at its periphery and which can be operated independently of one another and, when operated, undergo a change in their linear dimension, an operated piezoelectric element axially raising or lowering the workpiece holder at the point at which it supports the workpiece holder; a measuring probe for each piezoelectric element recording its linear dimension; and a central control unit for operating the piezoelectric elements.
Claim 2
Dependent Claim
122 words
A workpiece holder for a rotary grinding machine having a rotating grinding tool for grinding semiconductor wafers, said workpiece holder having a periphery and comprising a rotatable work surface which points toward the rotating grinding tool and on said surface the semiconductor wafer to be machined is laid; piezoelectric elements on which the workpiece holder is axially supported at its periphery and which can be operated independently of one another and, when operated, undergo a change in their linear dimension, an operated piezoelectric element axially raising or lowering the workpiece holder at the point at which it supports the workpiece holder; a measuring probe for each piezoelectric element recording its linear dimension; and a central control unit for operating the piezoelectric elements.
Claim 3
Dependent Claim
25 words
The workpiece holder as claimed in claim 1, wherein there are three piezoelectric elements which are provided for the axial support of the workpiece holder.
Claim 4
Dependent Claim
31 words
The workpiece holder as claimed in claim 1, further comprising suction means by which the semiconductor wafer to be machined is drawn against the rotatable work surface of the workpiece holder.
Claim 5
Independent Claim
155 words
A method of positioning a workpiece holder for a rotary grinding machine for grinding semiconductor wafers, having a rotatable work surface which points toward a rotating grinding tool and on which the semiconductor wafer to be machined is laid, and having piezoelectric elements on which the workpiece holder is axially supported at its periphery, each piezoelectric element being equipped with a measuring probe recording its linear dimension, wherein the piezoelectric elements can be operated independently of one another by a central control unit and, when operated, undergo a change in their linear dimension, an operated piezoelectric element axially raising or lowering the workpiece holder at the point at which it supports the workpiece holder; said method comprising operating said piezoelectric elements in such a manner that an axis of rotation of the workpiece holder and an axis of rotation of the grinding tool are oriented parallel or assume a defined position relative to one another.
Claim 6
Independent Claim
155 words
A method of positioning a workpiece holder for a rotary grinding machine for grinding semiconductor wafers, having a rotatable work surface which points toward a rotating grinding tool and on which the semiconductor wafer to be machined is laid, and having piezoelectric elements on which the workpiece holder is axially supported at its periphery, each piezoelectric element being equipped with a measuring probe recording its linear dimension, wherein the piezoelectric elements can be operated independently of one another by a central control unit and, when operated, undergo a change in their linear dimension, an operated piezoelectric element axially raising or lowering the workpiece holder at the point at which it supports the workpiece holder; said method comprising operating said piezoelectric elements in such a manner that an axis of rotation of the workpiece holder and an axis of rotation of the grinding tool are oriented parallel or assume a defined position relative to one another.
Claim 7
Dependent Claim
25 words
The method as claimed in claim 4, further comprising operating the piezoelectric elements in such a manner that the workpiece holder executes a feed movement.
Claim 8
Dependent Claim
46 words
The method as claimed in claim 4, further comprising during the grinding of a semiconductor wafer, measuring the axial cutting power of the rotary grinding machine with the aid of the piezoelectric elements; and repositioning said workpiece holder after an unforeseen variation of the cutting power.
Claim 9
Dependent Claim
140 words
In a method for grinding a semiconductor wafer, the improvement which comprises providing a workpiece holder for a rotary grinding machine having a rotating grinding tool for grinding semiconductor wafers, said workpiece holder having a periphery; placing a semiconductor wafer on a rotatable work surface which points toward the rotating grinding tool and on said surface the semiconductor wafer to be machined is laid; placing piezoelectric elements on which the workpiece holder is axially supported at its periphery and which can be operated independently of one another and, when operated, undergo a change in their linear dimension, an operated piezoelectric element axially raising or lowering the workpiece holder at the point at which it supports the workpiece holder; providing a measuring probe for each piezoelectric element recording its linear dimension; and operating the piezoelectric elements with a central control unit.
Claim 10
Dependent Claim
140 words
In a method for grinding a semiconductor wafer, the improvement which comprises providing a workpiece holder for a rotary grinding machine having a rotating grinding tool for grinding semiconductor wafers, said workpiece holder having a periphery; placing a semiconductor wafer on a rotatable work surface which points toward the rotating grinding tool and on said surface the semiconductor wafer to be machined is laid; placing piezoelectric elements on which the workpiece holder is axially supported at its periphery and which can be operated independently of one another and, when operated, undergo a change in their linear dimension, an operated piezoelectric element axially raising or lowering the workpiece holder at the point at which it supports the workpiece holder; providing a measuring probe for each piezoelectric element recording its linear dimension; and operating the piezoelectric elements with a central control unit.
Claim 11
Dependent Claim
15 words
The method as claimed in claim 4 wherein said semiconductor wafer is a silicon wafer.
Claim 12
Dependent Claim
17 words
The method as claimed in claim 4, wherein said semiconductor wafer is a silicon on insulator wafer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-10-22 | 2000-04-22 | 2000-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-10-22 | 2004-04-22 | 2004-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-10-22 | 2008-04-22 | 2008-10-22 | $7700.00 | Window Closed / Lapsed |