US5486721A
Expired / Lapsed
US
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Lead frame for integrated circuits
Assignee: WC HERAUS GmbH
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Filing: 1994-03-31
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Granted: 1996-01-23
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Expires: 2014-03-31
Abstract
Abstract Lead frames completely surface-plated with palladium have a nickel-phosphorus or copper-tin layer between the base element, made for example of copper, and the palladium layer. Such lead frames exhibit good bondability and good solderability without tinning.
Inventors
- 👤 Gunter Herklotz
- 👤 Heinz Forderer
- 👤 Thomas Frey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:40
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/456; H10W70/457; H10W72/00; H10W72/071; H10W72/075; H10W72/90; H10W72/951; H10W72/952; H10W90/00; H10W90/701; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
47 words
Lead frame for an integrated circuit, said lead frame comprising a metal base element, an outer layer of palladium, and an intermediate layer consisting of a nickel-phosphorus alloy between said base element and said outer layer, said intermediate layer having a phosphorus content of 1-30 wt %.
Claim 2
Dependent Claim
47 words
Lead frame for an integrated circuit, said lead frame comprising a metal base element, an outer layer of palladium, and an intermediate layer consisting of a nickel-phosphorus alloy between said base element and said outer layer, said intermediate layer having a phosphorus content of 1-30 wt %.
Claim 3
Dependent Claim
18 words
Lead frame as in claim 1 wherein said intermediate layer has a phosphorus content of 5-10 wt %.
Claim 4
Dependent Claim
14 words
Lead frame as in claim 1 wherein said intermediate layer is 0.01-5 millimeters thick.
Claim 5
Dependent Claim
14 words
Lead frame as in claim 3 wherein said intermediate layer is 0.2-2 millimeters thick.
Claim 6
Dependent Claim
18 words
Lead frame as in claim 1 further comprising a layer of nickel arranged directly on said base element.
Claim 7
Dependent Claim
15 words
Lead frame as in claim 5 wherein said layer of nickel is 1-2 micrometers thick.
Claim 8
Dependent Claim
14 words
Lead frame as in claim 1 wherein said palladium layer is 0.01-0.5 micrometers thick.
Claim 9
Dependent Claim
15 words
Lead frame as in claim 7 wherein said palladium layer is about 0.1 micrometers thick.
Claim 10
Dependent Claim
20 words
Lead frame as in claim 1 wherein said base element is made of one of copper and a copper alloy.
Claim 11
Dependent Claim
47 words
Lead frame for an integrated circuit, said lead frame comprising a metal base element, an outer layer of palladium, and an intermediate layer consisting of a copper-tin alloy between said base element and said outer layer, said intermediate layer having a tin content of 5-60 wt %.
Claim 12
Dependent Claim
47 words
Lead frame for an integrated circuit, said lead frame comprising a metal base element, an outer layer of palladium, and an intermediate layer consisting of a copper-tin alloy between said base element and said outer layer, said intermediate layer having a tin content of 5-60 wt %.
Claim 13
Dependent Claim
18 words
Lead frame as in claim 10 wherein said intermediate layer has a tin content of 10-30 wt %.
Claim 14
Dependent Claim
14 words
Lead frame as in claim 10 wherein said intermediate layer is 0.01-5 micrometers thick.
Claim 15
Dependent Claim
14 words
Lead frame as in claim 12 wherein said intermediate layer is 0.2-2 micrometers thick.
Claim 16
Dependent Claim
18 words
Lead frame as in claim 10 further comprising a layer of nickel arranged directly on said base element.
Claim 17
Dependent Claim
15 words
Lead frame as in claim 14 wherein said layer of nickel is 1-2 micrometers thick.
Claim 18
Dependent Claim
14 words
Lead frame as in claim 10 wherein said palladium layer is 0.01-0.5 micrometers thick.
Claim 19
Dependent Claim
15 words
Lead frame as in claim 16 wherein said palladium layer is about 0.1 micrometers thick.
Claim 20
Dependent Claim
20 words
Lead frame as in claim 10 wherein said base element is made of one of copper and a copper alloy.
Claim 21
Dependent Claim
25 words
Lead frame as in claim 10 wherein said intermediate layer completely covers said metal base element, and said outer layer completely covers said intermediate layer.
Claim 22
Dependent Claim
25 words
Lead frame as in claim 1 wherein said intermediate layer completely covers said metal base element, and said outer layer completely covers said intermediate layer.
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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) | 1999-01-22 | 1999-07-24 | 2000-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-22 | 2003-07-24 | 2004-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-22 | 2007-07-24 | 2008-01-23 | $7700.00 | Window Closed / Lapsed |