US4813840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of aligning wafers and device therefor
Assignee: Applied Materials Inc
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Filing: 1987-08-11
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Granted: 1989-03-21
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Expires: 2007-08-11
Abstract
Abstract A cassette of conventional form is loaded with a plurality of semiconductor wafers having indexing flats of the known type and placed over three parallel rollers rotatably secured to a frame. The three rollers include a center roller and two side rollers positioned only slightly higher than the center roller such that their rotary motions can be communicated to the wafers by contact, depending on the position of the individual indexing flats. The indexing flats are roughly aligned in downward directions first by rotating only the center roller and after all three rollers are rotated to bring the indexing flats in upward directions, the wafers are more accurately aligned in a downward direction by rotating only the center roller and all three rollers are rotated thereafter for a predetermined period of time, depending on the desired angular position of the indexing flats.
Inventors
- 👤 Rakesh Prabhakar
- 👤 A. Fernando Benavides
- 👤 Petru Nitescu
- 👤 Peter Ebbing
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:38
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/50; Y; Y10; Y10S; Y10S414/00; Y10S414/135; Y10S414/136
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
222 words
A device for aligning disks in a specified angular orientation, said disks each having a generally circular periphery with a predetermined curvature and an indexing flat of a predetermined length along a chord, said disks being supported substantially vertically in a substantially horizontally disposed cassette in mutually spaced apart and substantially coaxial relationship, said cassette being substantially open at bottom such that said disks supported in said cassette are accessible from below, said device comprising a frame adapted for said cassette to be set substantially horizontally thereon, a center roller and two side rollers which flank said center roller, said rollers being rotatably supported around axes which are unchangeably fixed with respect to each other and to said frame and each adapted to impart frictional force to said wafers in said cassette through contacts with the peripheries thereof, said rollers being so positioned with respect to said frame that, when said cassette is set on said frame, those of said wafers with the indexing flats not oriented in a downward direction contact said center roller without touching either of said side rollers and those of said wafers with the indexing flats oriented in a downward direction all have their generally circular peripheries in contact with one or both of said side rollers, and driving means for selectively causing said rollers to rotate.
Claim 2
Independent Claim
222 words
A device for aligning disks in a specified angular orientation, said disks each having a generally circular periphery with a predetermined curvature and an indexing flat of a predetermined length along a chord, said disks being supported substantially vertically in a substantially horizontally disposed cassette in mutually spaced apart and substantially coaxial relationship, said cassette being substantially open at bottom such that said disks supported in said cassette are accessible from below, said device comprising a frame adapted for said cassette to be set substantially horizontally thereon, a center roller and two side rollers which flank said center roller, said rollers being rotatably supported around axes which are unchangeably fixed with respect to each other and to said frame and each adapted to impart frictional force to said wafers in said cassette through contacts with the peripheries thereof, said rollers being so positioned with respect to said frame that, when said cassette is set on said frame, those of said wafers with the indexing flats not oriented in a downward direction contact said center roller without touching either of said side rollers and those of said wafers with the indexing flats oriented in a downward direction all have their generally circular peripheries in contact with one or both of said side rollers, and driving means for selectively causing said rollers to rotate.
Claim 3
Dependent Claim
19 words
The device of claim 1 wherein said side rollers have higher peripheral surface position than said center roller has.
Claim 4
Dependent Claim
21 words
The device of claim 1 wherein said driving means include three motors which are individually in motion-communicating relationship with said rollers.
Claim 5
Dependent Claim
18 words
The device of claim 1 further comprising motion-communicating means for correlating the rotary motion of said side rollers.
Claim 6
Dependent Claim
21 words
The device of claim 4 wherein said driving means include a single motor and said motion-communicating means include a gear train.
Claim 7
Dependent Claim
85 words
The device of claim 5 wherein said gear train includes a center-axis gear which is affixed to the axis of said center roller and side-axis gears which are respectively affixed to and rotate with said side rollers, said center-axis gear being adapted to rotate freely around the axis of said center roller when said center roller rotates in one direction but to lock thereonto when said center roller rotates in the other direction, said center-axis gear being in motion-communcatably engaged relationship with said side-axis gears.
Claim 8
Dependent Claim
15 words
The device of claim 1 wherein said rollers have surfaces made from a compliant material.
Claim 9
Dependent Claim
12 words
The device of claim 1 wherein said rollers comprise 75-80 durometer polyurethane.
Claim 10
Dependent Claim
14 words
The device of claim 1 wherein said central and side rollers have same diameter.
Claim 11
Independent Claim
234 words
A method of aligning disks in a specified angular orientation, said disks each having a generally circular periphery with a predetermined curvature and an indexing flat of a predetermined length along a chord, said disks being supported substantially vertically in mutually spaced apart and substantially coaxial relationship, said method comprising the steps of setting a cassette on a frame, said cassette being loaded with said disks and adapted to support said disks substantially vertically and in mutually spaced apart and coaxial relationship, said cassette being substantially open at bottom such that said disks supported therein are accessible from below, a center roller and two side rollers which flank said center roller being rotatably supported around axes which are fixed with respect to said frame, said rollers being so positioned with respect to said frame that, when said cassette is set on said frame, those of said disks with the indexing flats not oriented in a downward direction contact said center roller without touching either of said side rollers and those of said wafers with the indexing flats oriented in a downward direction contact one or both of said side rollers, causing said wafers to rotate by rotating only said center roller until the indexing flats of all said wafers in said cassette are oriented in approximately downward directions, and causing all three of said rollers to rotate until said specified angular orientation is achieved.
Claim 12
Independent Claim
234 words
A method of aligning disks in a specified angular orientation, said disks each having a generally circular periphery with a predetermined curvature and an indexing flat of a predetermined length along a chord, said disks being supported substantially vertically in mutually spaced apart and substantially coaxial relationship, said method comprising the steps of setting a cassette on a frame, said cassette being loaded with said disks and adapted to support said disks substantially vertically and in mutually spaced apart and coaxial relationship, said cassette being substantially open at bottom such that said disks supported therein are accessible from below, a center roller and two side rollers which flank said center roller being rotatably supported around axes which are fixed with respect to said frame, said rollers being so positioned with respect to said frame that, when said cassette is set on said frame, those of said disks with the indexing flats not oriented in a downward direction contact said center roller without touching either of said side rollers and those of said wafers with the indexing flats oriented in a downward direction contact one or both of said side rollers, causing said wafers to rotate by rotating only said center roller until the indexing flats of all said wafers in said cassette are oriented in approximately downward directions, and causing all three of said rollers to rotate until said specified angular orientation is achieved.
Claim 13
Dependent Claim
21 words
The method of claim 10 wherein said wafers are rotated substantially through rolling contact with one or more of said rollers.
Claim 14
Dependent Claim
19 words
The method of claim 10 wherein said side rollers have higher peripheral surface position than said center roller has.
Claim 15
Dependent Claim
61 words
The method of claim 10 further comprising the step of preliminarily rotating said center roller with said side rollers kept stationary until said indexing flats of all said wafers in said cassette are in approximately downward directions, and then rotating all three of said rollers together for a predetermined length of time to reorient said indexing flats from said downward directions.
Claim 16
Dependent Claim
19 words
The method of claim 13 wherein said side rollers have higher peripheral surface position than said center roller has.
Claim 17
Dependent Claim
19 words
The method of claim 10 further comprising the step of stopping the rotation of said rollers by controlling deceleration.
Claim 18
Dependent Claim
19 words
The method of claim 13 further comprising the step of stopping the rotation of said rollers by controlling deceleration.
References Cited (Backward Citations)
US3297134A
Cited
US3982627A
Cited
US4441853A
Cited
US4311427A
Cited
US4376482A
Cited
US4662811A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-20 | 1992-09-19 | 1993-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-20 | 1996-09-19 | 1997-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-20 | 2000-09-19 | 2001-03-21 | $7700.00 | Window Closed / Lapsed |