US5528076A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Leadframe having metal impregnated silicon carbide mounting area
Assignee: Motorola Solutions Inc
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Filing: 1995-02-01
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Granted: 1996-06-18
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Expires: 2015-02-01
Abstract
Abstract A leadframe (10) formed by a method including providing a preform of silicon carbide, placing the preform in a mold, injecting a liquefied metal, such as aluminum, into the mold to fill the mold and infiltrate the preform, using heat and pressure. The mold defines a mounting area (12) in which the preform is positioned, and a plurality of leads (20, 22, 28, 29).
Inventors
- 👤 Jeanne S. Pavio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 00:11
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/01; H10W70/04; H10W90/00; H10W90/701; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
35 words
A leadframe for semiconductor devices comprising: a semiconductor device mounting area formed of a metal impregnated silicon carbide; and a plurality of electrically conductive leads substantially comprised of a metal coupled to said mounting area.
Claim 2
Dependent Claim
35 words
A leadframe for semiconductor devices comprising: a semiconductor device mounting area formed of a metal impregnated silicon carbide; and a plurality of electrically conductive leads substantially comprised of a metal coupled to said mounting area.
Claim 3
Dependent Claim
14 words
A leadframe as claimed in claim 1 wherein the metal is comprised of aluminum.
Claim 4
Dependent Claim
29 words
A leadframe as claimed in claim 1 wherein the coefficient of thermal expansion of the mounting area is substantially similar to the coefficient of thermal expansion of gallium arsenide.
Claim 5
Dependent Claim
28 words
A leadframe as claimed in claim 1 wherein the coefficient of thermal expansion of the mounting area is substantially similar to the coefficient of thermal expansion of silicon.
Claim 6
Dependent Claim
31 words
A leadframe as claimed in claim 1 wherein the coefficient of thermal expansion of the mounting area is less than or equal to approximately 10 parts per million per degree Celsius.
Claim 7
Dependent Claim
117 words
A semiconductor package comprising: a semiconductor device having electrical terminals; a leadframe including a semiconductor device mounting area with a first surface and an opposing surface, formed of a metal impregnated silicon carbide and having a coefficient of thermal expansion substantially similar to a semiconductor material and a plurality of electrically conductive leads integrally formed with said mounting area, said plurality of electrically condutuctive leads comprised substantially of a metal; the semiconductor device being mounted on the mounting area of the leadframe with at least some of the electrical terminals electrically connected to the plurality of electrically conductive leads; and an encapsulating material surrounding the device and the mounting area with leads and the opposing surface exposed.
Claim 8
Dependent Claim
117 words
A semiconductor package comprising: a semiconductor device having electrical terminals; a leadframe including a semiconductor device mounting area with a first surface and an opposing surface, formed of a metal impregnated silicon carbide and having a coefficient of thermal expansion substantially similar to a semiconductor material and a plurality of electrically conductive leads integrally formed with said mounting area, said plurality of electrically condutuctive leads comprised substantially of a metal; the semiconductor device being mounted on the mounting area of the leadframe with at least some of the electrical terminals electrically connected to the plurality of electrically conductive leads; and an encapsulating material surrounding the device and the mounting area with leads and the opposing surface exposed.
Claim 9
Dependent Claim
25 words
A semiconductor package as claimed in claim 6 wherein said semiconductor device includes a gallium arsenide chip being larger than 0.050 inches by 0.050 inches.
Claim 10
Dependent Claim
24 words
A semiconductor package as claimed in claim 6 wherein said semiconductor device includes a silicon chip being larger than 0.150 inches by 0.150 inches.
Claim 11
Dependent Claim
15 words
A semiconductor package as claimed in claim 8 wherein the metal is comprised of aluminum.
Claim 12
Dependent Claim
16 words
A semiconductor package as claimed in claim 6 wherein the encapsulating material is comprised of plastic.
References Cited (Backward Citations)
US5014113A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-06-18 | 1999-12-18 | 2000-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-06-18 | 2003-12-18 | 2004-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-06-18 | 2007-12-18 | 2008-06-18 | $7700.00 | Window Closed / Lapsed |