Patent US4746390A successfully refreshed from Google Patents.
US4746390A
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Method for joining a semiconductor chip to a chip carrier
Assignee: Siemens AG
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Filing: 1982-07-29
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Granted: 1988-05-24
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Expires: 2002-07-29
Abstract
Abstract Method of joining a semiconductor chip to a chip carrier by cementing or soldering which includes treating an area of the semiconductor chip to be joined to the carrier with a laser beam, adjusting the energy of the laser beam to produce depressions by localizing melting of the semiconductor material of the chip and to at least partially pile melted semiconductor material at the edge of the depression, and applying cement or solder between the treated area of the semiconductor chip and the carrier.
Inventors
- 👤 Radim Badalec
- 👤 Werner Baumgartner
- 👤 David Cutter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:10
CPC Classifications
H; H10; H10P; H10P34/00; H10P34/40; H10P34/42; H10W; H10W72/00; H10W72/30; H10W72/071; H10W72/073; H10W72/07331; H10W72/07336; H10W72/07337; H10W72/351; H10W72/352; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
102 words
Method of joining a semiconductor chip to a chip carrier by cementing or soldering, which comprises treating an area of the semiconductor chip to be joined to the carrier with a laser beam, adjusting the energy of the laser beam to produce depressions in the semiconductor chip by localized melting of the semiconductor material of the chip and to at least partially pile melted semiconductor material on the surface of the semiconductor chip at the edge of the depression, and applying cement or solder between the treated area of the semiconductor chip containing the depressions and the piled material and the carrier.
Claim 2
Dependent Claim
102 words
Method of joining a semiconductor chip to a chip carrier by cementing or soldering, which comprises treating an area of the semiconductor chip to be joined to the carrier with a laser beam, adjusting the energy of the laser beam to produce depressions in the semiconductor chip by localized melting of the semiconductor material of the chip and to at least partially pile melted semiconductor material on the surface of the semiconductor chip at the edge of the depression, and applying cement or solder between the treated area of the semiconductor chip containing the depressions and the piled material and the carrier.
Claim 3
Dependent Claim
46 words
Method according to claim 1, which comprises forming the depressions with a diameter of between 50 and 200 μm and a depth of between 2 and 10 μm, and piling the semiconductor material ejected from the depressions at a height of between 2 and 10 μm.
Claim 4
Dependent Claim
24 words
Method according to claim 1 or 2, which comprises using a pulsed Nd:YAG laser for treating the area of the chip to be joined.
Claim 5
Dependent Claim
16 words
Method according to claim 1, which comprises performing the melting step in a protective gas atmosphere.
Claim 6
Dependent Claim
16 words
Method according to claim 1, which comprises performing the melting step in a reactive gas atmosphere.
Claim 7
Dependent Claim
21 words
Method according to claim 1, which comprises metallizing the area of the semiconductor chip to be joined after the laser treatment.
References Cited (Backward Citations)
US3945111A
Cited
US4028523A
Cited
US4050507A
Cited
US4200382A
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US4360965A
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US4288678A
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US4257827A
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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) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |