US5631408A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making disk bumps with laser pulses
Assignee: International Business Machines Corp
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Filing: 1996-02-27
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Granted: 1997-05-20
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Expires: 2016-02-27
Abstract
Abstract A method is provided for making crater shaped bumps on a magnetic disk. The crater shaped bumps have a diameter in the range of 10 to 25 μm and a peripheral ridge with a height h r above a nominal surface of the calibration disk in the range of 75 to 120 nm. Close tolerance crater shaped bumps with this configuration can be made by impinging two or more pulses of laser energy on the same location of the disk. By increasing the number of pulses the height of the peripheral ridge progressively increases. By employing multiple pulses, the height of the peripheral ridge is increased while the diameter of the crater shaped bump stays substantially constant. Further, by employing multiple pulses diameters and heights of crater shaped bumps can be produced with close tolerances within a diameter range of 5 to 20 μm and a height range of 2 to 120 nm.
Inventors
- 👤 Peter M. Baumgart
- 👤 Karl A. Flechsig
- 👤 Michael F. Lee
- 👤 Wing P. Leung
- 👤 Ullal V. Nayak
- 👤 Thao A. Nguyen
- 👤 Timothy C. O'Sullivan
- 👤 Andrew C. Tam
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:15
CPC Classifications
B; B23; B23K; B23K26/00; B23K26/08; B23K26/0823; B82; B82Y; B82Y10/00; B82Y15/00; G; G11; G11B; G11B33/00; G11B33/10; G11B5/00; G11B5/74; G11B5/82; G11B5/84; G11B5/8404; G11B5/8408; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49995
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
102 words
A method of making a crater shaped bump on an article, the crater shaped bump having a peripheral ridge which projects upwardly from a nominal surface of the article a predetermined height h r comprising the steps of: maintaining a laser source in a fixed position; maintaining the article in a fixed position; and while maintaining the article and laser source in fixed positions impinging at least two pulses of laser energy on a surface of the article until the peripheral ridge of the crater shaped bump projects upwardly from the nominal surface of the article said predetermined height h r .
Claim 2
Independent Claim
102 words
A method of making a crater shaped bump on an article, the crater shaped bump having a peripheral ridge which projects upwardly from a nominal surface of the article a predetermined height h r comprising the steps of: maintaining a laser source in a fixed position; maintaining the article in a fixed position; and while maintaining the article and laser source in fixed positions impinging at least two pulses of laser energy on a surface of the article until the peripheral ridge of the crater shaped bump projects upwardly from the nominal surface of the article said predetermined height h r .
Claim 3
Dependent Claim
51 words
A method as claimed in claim 1 including: the diameter D r of the crater shaped bump being in the range of 5 to 20 μm; and the height h r of the peripheral ridge above the nominal surface of the article being in the range of 2 to 120 nm.
Claim 4
Dependent Claim
24 words
A method as claimed in claim 2 wherein the laser energy has a fluence in the range of 3.3 to 7.8 J/cm 2 .
Claim 5
Dependent Claim
29 words
A method as claimed in claim 2 wherein a duration of a single pulse of laser energy on the surface of the calibration disk is less than 100 ns.
Claim 6
Dependent Claim
24 words
A method as claimed in claim 4 wherein the laser energy has a fluence in the range of 3.3 to 7.8 J/cm 2 .
Claim 7
Dependent Claim
17 words
A method as claimed in claim 1 wherein the article is a layer of NiP plated Al.
Claim 8
Dependent Claim
51 words
A method as claimed in claim 1 wherein the diameter D r of the crater shaped bump is in the range of 15 to 25 μm and the height h r of the peripheral ridge above the nominal surface of the article is in the range of 75 to 120 nm.
Claim 9
Dependent Claim
43 words
A method as claimed in claim 7 wherein the article is a magnetic calibration disk comprising a NiP plated Al layer, a Cr layer and a magnetizable layer, the Cr layer being sandwiched between the NiP plated Al layer and the magnetizable layer.
Claim 10
Dependent Claim
58 words
A method as claimed in claim 8 wherein said step of impinging at least two pulses of laser energy comprises impinging said at least two pulses of laser energy on a surface of the NiP plated Al layer; coating the NiP plated Al layer with the Cr layer and then coating the Cr layer with the magnetizable layer.
Claim 11
Dependent Claim
46 words
A method as claimed in claim 8 wherein said step of impinging at least two pulses of laser energy comprises impinging the at least two pulses of laser energy on a surface of the Cr layer and then coating the Cr layer with the magnetizable layer.
Claim 12
Dependent Claim
36 words
A method as claimed in claim 8 wherein said step of impinging at least two pulses of laser energy comprises impinging the at least two pulses of laser energy on a surface of the magnetizable layer.
Claim 13
Dependent Claim
15 words
A method as claimed in claim 11 wherein the magnetizable layer is a Co alloy.
Claim 14
Dependent Claim
51 words
A method as claimed in claim 1 wherein the diameter D r of the crater shaped bump is in the range of 5 to 20 μm and the height h r of the peripheral ridge above the nominal surface of the article is in the range of 2 to 584 nm.
Claim 15
Dependent Claim
43 words
A method as claimed in claim 13 wherein the article is a magnetic recording disk comprising a NiP plated Al layer, a Cr layer and a magnetizable layer, the Cr layer being sandwiched between the NiP plated Al layer and the magnetizable layer.
Claim 16
Dependent Claim
58 words
A method as claimed in claim 14 wherein said step of impinging at least two pulses of laser energy comprises impinging said at least two pulses of laser energy on a surface of the NiP plated Al layer; coating the NiP plated Al layer with the Cr layer and then coating the Cr layer with the magnetizable layer.
Claim 17
Dependent Claim
46 words
A method as claimed in claim 14 wherein said step of impinging at least two pulses of laser energy comprises impinging the at least two pulses of laser energy on a surface of the Cr layer and then coating the Cr layer with the magnetizable layer.
Claim 18
Dependent Claim
36 words
A method as claimed in claim 14 wherein said step of impinging at least two pulses of laser energy comprises impinging the at least two pulses of laser energy on a surface of the magnetizable layer.
Claim 19
Dependent Claim
15 words
A method as claimed in claim 17 wherein the magnetizable layer is a Co alloy.
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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) | 2000-05-19 | 2000-11-18 | 2001-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-05-19 | 2004-11-18 | 2005-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-05-19 | 2008-11-18 | 2009-05-20 | $7700.00 | Window Closed / Lapsed |