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US4947237A Expired / Lapsed US ⏱️ 0.0 years remaining

Lead frame assembly for integrated circuits having improved heat sinking capabilities and method

Assignee: STMicroelectronics SRL
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Filing: 1987-10-01
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Granted: 1990-08-07
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Expires: 2007-10-01
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Abstract

Abstract An integrated circuit package is described that provides increased heat dissipation of heat generated in an integrated circuit chip that can be positioned within the package. This increased heat dissipation characteristic is achieved by configuring enlarged metal areas of the lead frame of the package that are extensions of the flag area. The flag area is the portion of the lead frame to which the integrated circuit chip is mounted in the assembly of the semiconductor package. The increased lead frame area provides increased contact with the package housing and provides a thermal conduction path in close proximity to the exterior surface of the package housing. The integrated circuit chip has a more efficient thermal path to the ambient air thermal heat sink.

Inventors

  • 👤 Marzio Fusaroli

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 20:47
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/461

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 144 words
A semiconductor integrated circuit package including a package housing partially enclosing a lead frame having leads extending from four sides of said package housing, comprising, in combination: central flag means in said lead frame for supporting a semiconductor chip, said flag means having four corners, said a package housing enclosing said central flag means of said lead frame, said package housing having four corners; and heat spreading means in said lead frame for conducting heat from said semiconductor chip, said heat spreading means being integral with said central flag means and extending from at least one of said four corners of said central flag means towards one of said four corners of said package housing and extending out of said package housing on two adjacent sides of said package housing, said heat spreading means increasing in width with distance from said central flag means.
Claim 2
Dependent Claim 144 words
A semiconductor integrated circuit package including a package housing partially enclosing a lead frame having leads extending from four sides of said package housing, comprising, in combination: central flag means in said lead frame for supporting a semiconductor chip, said flag means having four corners, said a package housing enclosing said central flag means of said lead frame, said package housing having four corners; and heat spreading means in said lead frame for conducting heat from said semiconductor chip, said heat spreading means being integral with said central flag means and extending from at least one of said four corners of said central flag means towards one of said four corners of said package housing and extending out of said package housing on two adjacent sides of said package housing, said heat spreading means increasing in width with distance from said central flag means.
Claim 3
Dependent Claim 34 words
The semiconductor integrated circuit package according to claim 1 wherein said heat spreading means extends from each of said four corners of said central flag means towards a respective corner of said package housing.
Claim 4
Dependent Claim 31 words
The semiconductor integrated circuit package according to claim 1 wherein said heat spreading means extends out of said package housing in two places on a single side of said package housing.
Claim 5
Dependent Claim 31 words
The semiconductor integrated circuit package according to claim 2 wherein said heat spreading means extends out of said package housing in two places on a single side of said package housing.

References Cited (Backward Citations)

US4066839A Cited
US4141029A Cited
US4527185A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-08-06 1994-02-05 1994-08-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-08-06 1998-02-05 1998-08-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-08-06 2002-02-05 2002-08-07 $7700.00 Window Closed / Lapsed

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