US5844305A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lead frame for semiconductor devices
Assignee: Samsung Electronics Co Ltd
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Filing: 1995-01-12
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Granted: 1998-12-01
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Expires: 2015-01-12
Abstract
Abstract A lead frame for a semiconductor device, comprising; a die pad having a major surface upon which a semiconductor die is placed, the major surface being clad with a metal layer, an inner lead portion electrically connected to the semiconductor die, wherein the die pad and the inner lead portion are embedded within a molding resin, and an outer lead portion exposed outside the molding resin, electrically connected to the inner lead portion, and adapted for connection to a printed circuit board land, wherein the die pad, inner lead portion, and outer lead portion are formed from a metal having a thermal expansion coefficient equal to that of the printed wiring board land.
Inventors
- 👤 Young Eui Shin
- 👤 Kyung Seob Kim
- 👤 Min Bin Yim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:30
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/456; H10W70/457; H10W70/01; H10W70/04; H10W70/411; H10W70/451; H10W90/00; H10W90/811; H10W70/421; H10W70/424; H10W70/427; H10W70/429; H10W72/00; H10W72/50; H10W72/531; H10W72/536; H10W72/5363; H10W72/851; H10W72/874; H10W72/884; H10W74/00; H10W90/701; H10W90/731; H10W90/736; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
145 words
A lead frame for a semiconductor device adapted to be connected to a printed circuit board land, comprising: a die pad upon which a semiconductor die is placed; an inner lead portion having a first thickness, electrically connected to the semiconductor die, wherein the die pad and the inner lead portion are embedded within a molding resin, and wherein the die pad and the inner lead portion are clad with a metal layer formed of a nickel-iron alloy having a second thickness in a range of from 10% to 40% the first thickness; and an outer lead portion electrically connected to the inner lead portion, and formed from a metal having a thermal expansion coefficient equal to that of the printed circuit board land, the outer lead portion extending outside the molding resin, such that the outer lead portion is exposed to an external environment.
Claim 2
Dependent Claim
145 words
A lead frame for a semiconductor device adapted to be connected to a printed circuit board land, comprising: a die pad upon which a semiconductor die is placed; an inner lead portion having a first thickness, electrically connected to the semiconductor die, wherein the die pad and the inner lead portion are embedded within a molding resin, and wherein the die pad and the inner lead portion are clad with a metal layer formed of a nickel-iron alloy having a second thickness in a range of from 10% to 40% the first thickness; and an outer lead portion electrically connected to the inner lead portion, and formed from a metal having a thermal expansion coefficient equal to that of the printed circuit board land, the outer lead portion extending outside the molding resin, such that the outer lead portion is exposed to an external environment.
Claim 3
Dependent Claim
32 words
The lead frame of claim 1, wherein the metal forming the die pad, inner lead portion, and outer lead portion is one selected from a group consisting of copper and copper alloy.
Claim 4
Dependent Claim
23 words
The lead frame of claim 1, wherein the metal layer is formed from an alloy having a melting point less than 180° C.
Claim 5
Dependent Claim
21 words
The lead frame of claim 1, wherein the metal layer is thermal compression bonded to at least said inner lead portion.
Claim 6
Dependent Claim
21 words
The lead frame of claim 2, wherein the metal layer is thermal compression bonded to at least said inner lead portion.
Claim 7
Dependent Claim
21 words
The lead frame of claim 3, wherein the metal layer is thermal compression bonded to at least said inner lead portion.
References Cited (Backward Citations)
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US5276351A
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US5134459A
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US5329158A
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US5455446A
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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) | 2001-11-30 | 2002-06-01 | 2002-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-30 | 2006-06-01 | 2006-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-30 | 2010-06-01 | 2010-12-01 | $7700.00 | Window Closed / Lapsed |