Patent US4611238A successfully refreshed from Google Patents.
US4611238A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated circuit package incorporating low-stress omnidirectional heat sink
Assignee: Unisys Corp
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Filing: 1985-07-15
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Granted: 1986-09-09
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Expires: 2005-07-15
Abstract
Abstract Disclosed is a heat sink for cooling an integrated circuit package. The heat sink comprises a single thin sheet of material having two oppositely facing major surfaces. These two major surfaces have a common perimeter defining a plurality of spaced-apart finger-shaped portions of the thin sheet of material that extend radially from a central portion of the sheet. The central portion is convex for attachment to the integrated circuit package; and the finger-shaped portions are formed to extend out of the plane of the central portion to become cooling fins for the central portion.
Inventors
- 👤 Terrence E. Lewis
- 👤 Stephen A. Smiley
- 👤 Rex Rice
- 👤 Zeev Lipkes
- 👤 John A. Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:18
CPC Classifications
H; H10; H10W; H10W40/00; H10W40/60; H10W40/611; H10W40/20; H10W40/22; H10W40/226; H10W40/231; H10W40/235; H10W72/00; H10W72/50; H10W72/531; H10W72/5363
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
95 words
A heat sink for cooling an integrated circuit package, said heat sink comprising: a single thin sheet of material having two oppositely facing major surfaces; said major surfaces having a common perimeter defining a central section and a plurality of spaced-apart finger-shaped portions that extend radially from said central section; said finger-shaped portions being formed to extend away from said central section to become cooling fins for said central section; and said central section having a convex shape for attachment to a flat surface on said integrated circuit package with an adhesive of nonuniform thickness.
Claim 2
Dependent Claim
95 words
A heat sink for cooling an integrated circuit package, said heat sink comprising: a single thin sheet of material having two oppositely facing major surfaces; said major surfaces having a common perimeter defining a central section and a plurality of spaced-apart finger-shaped portions that extend radially from said central section; said finger-shaped portions being formed to extend away from said central section to become cooling fins for said central section; and said central section having a convex shape for attachment to a flat surface on said integrated circuit package with an adhesive of nonuniform thickness.
Claim 3
Dependent Claim
29 words
A heat sink according to claim 1 wherein the convex shape of said central section bulges outward by at least one-twentieth the length of half of its cross section.
Claim 4
Dependent Claim
32 words
A heat sink according to claim 1 wherein the convex shape of said central section has a cross section which is curved like part of a circle, an ellipse, or a parabola.
Claim 5
Dependent Claim
34 words
A heat sink according to claim 1 wherein said cooling fins have a set of holes for receiving posts to prevent said heat sink from tipping as it rests on said convex central section.
Claim 6
Dependent Claim
36 words
A heat sink according to claim 1 wherein said finger-shaped portions bend away from said central section at an angle of 60°-90°, and thereafter bend in an opposite direction to lie parallel to said central section.
Claim 7
Dependent Claim
22 words
A heat sink according to claim 1 wherein said finger-shaped portions bend away from said central section in a gradual, arc-like fashion.
Claim 8
Dependent Claim
22 words
A heat sink according to claim 1 wherein all of said finger-shaped portions terminate at the same distance from said central section.
Claim 9
Dependent Claim
27 words
A heat sink according to claim 1 wherein said finger-shaped portions terminate in a cyclical fashion at relatively large and relatively small distances from said central section.
Claim 10
Dependent Claim
20 words
A heat sink according to claim 1 wherein the said finger-shaped portions twist along respective axes at a predetermined angle.
Claim 11
Dependent Claim
155 words
An integrated circuit package comprising: a planar substrate having flat top and bottom surfaces, said top surface having a cavity in which a semiconductor chip is disposed, a lid which covers said cavity and said semiconductor chip and which is sealed by a sealant to said top surface, and a heat sink that is attached by an adhesive to said bottom surface; said heat sink consisting of a single thin sheet of material which is shaped to have a central section and a plurality of spaced-apart finger-shaped sections that extend radially from said central section; said central section being the only part of said heat sink that is attached by said adhesive to said bottom surface, and said finger-shaped sections being curved away from said bottom surface to become cooling fins for said central section; said central section having a convex shape and said adhesive being progressively thicker towards the periphery of said central section.
Claim 12
Dependent Claim
155 words
An integrated circuit package comprising: a planar substrate having flat top and bottom surfaces, said top surface having a cavity in which a semiconductor chip is disposed, a lid which covers said cavity and said semiconductor chip and which is sealed by a sealant to said top surface, and a heat sink that is attached by an adhesive to said bottom surface; said heat sink consisting of a single thin sheet of material which is shaped to have a central section and a plurality of spaced-apart finger-shaped sections that extend radially from said central section; said central section being the only part of said heat sink that is attached by said adhesive to said bottom surface, and said finger-shaped sections being curved away from said bottom surface to become cooling fins for said central section; said central section having a convex shape and said adhesive being progressively thicker towards the periphery of said central section.
Claim 13
Dependent Claim
59 words
An integrated circuit package comprising a substrate, a heat sink having a central section which is attached via an adhesive to said package, said section having a convex shape which bulges outward by at least one-twentieth the length of half its cross section, and said adhesive being thicker at the periphery of said central section than at its center.
Claim 14
Dependent Claim
59 words
An integrated circuit package comprising a substrate, a heat sink having a central section which is attached via an adhesive to said package, said section having a convex shape which bulges outward by at least one-twentieth the length of half its cross section, and said adhesive being thicker at the periphery of said central section than at its center.
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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) | 1989-09-08 | 1990-03-10 | 1990-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-08 | 1994-03-10 | 1994-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-08 | 1998-03-10 | 1998-09-09 | $7700.00 | Window Closed / Lapsed |