US5710456A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silver spot/palladium plate lead frame finish
Assignee: Texas Instruments Inc
•
Filing: 1995-06-07
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Granted: 1998-01-20
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Expires: 2015-06-07
Abstract
Abstract A lead frame is plated with palladium and then selected portions of the lead frame leads are spot plated with silver to improve solderability.
Inventors
- 👤 Donald C. Abbott
- 👤 Robert M. Fritzsche
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:15
CPC Classifications
C; C23; C23C; C23C28/00; C23C28/02; C23C28/023; H; H10; H10W; H10W70/00; H10W70/40; H10W70/456; H10W70/457; H10W72/00; H10W72/071; H10W72/075; H10W72/50; H10W72/551; H10W72/552; H10W72/5522; H10W72/59; H10W72/90; H10W72/951; H10W72/952; H10W90/00; H10W90/701; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
67 words
A lead frame for a semiconductor device including a device mounting pad and lead frame leads, said lead frame comprising: a copper base metal; an intermediate plating layer plated entirely over said copper base metal comprising nickel or palladium; and a plurality of silver spot layers selectively plated over said intermediate plating layer at selected places on said lead frame leads close to the device mounting pad.
Claim 2
Dependent Claim
67 words
A lead frame for a semiconductor device including a device mounting pad and lead frame leads, said lead frame comprising: a copper base metal; an intermediate plating layer plated entirely over said copper base metal comprising nickel or palladium; and a plurality of silver spot layers selectively plated over said intermediate plating layer at selected places on said lead frame leads close to the device mounting pad.
Claim 3
Dependent Claim
20 words
The lead frame of claim 1, wherein said intermediate plating layer comprising nickel or palladium comprises a palladium nickel alloy.
Claim 4
Dependent Claim
23 words
The lead frame of claim 1, wherein said intermediate plating layer further comprises a layer of nickel covered by a layer of palladium.
Claim 5
Dependent Claim
17 words
The lead frame of claim 1, wherein said intermediate plating layer comprises a layer of palladium alloy.
Claim 6
Dependent Claim
28 words
The lead frame of claim 1, and further comprising: a copper spot plating placed over said intermediate layer and beneath said silver spot plating at said selected places.
Claim 7
Dependent Claim
23 words
The lead frame of claim 1, and further comprising: a spot plating of silver placed over said intermediate layer on said mounting pad.
Claim 8
Dependent Claim
28 words
The lead frame of claim 6 and further comprising: a spot plating of copper placed on said mounting pad and underneath said spot silver on said mounting pad.
References Cited (Backward Citations)
US5138431A
Cited
US5561320A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-01-19 | 2001-07-21 | 2002-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-01-19 | 2005-07-21 | 2006-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-01-19 | 2009-07-21 | 2010-01-20 | $7700.00 | Window Closed / Lapsed |