Patent US4899210A successfully refreshed from Google Patents.
US4899210A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat sink
Assignee: MUFG Union Bank NA
•
Filing: 1988-01-20
•
Granted: 1990-02-06
•
Expires: 2008-01-20
Abstract
Abstract A heat sink adapted for use with VLSI and other integrated circuit elements which includes a base adapted to be in thermal contact with the element to be cooled, there preferably being at least one projection from the side of the base adapted to be adjacent to the element, and a plurality of pins extending from the other side of the base in a direction substantially perpendicular thereto. The projection from the base may either be in the form of a center pedestal which is secured to the element to be cooled by a suitable adhesive, limiting the thermal stress area, or may be a plurality of projections formed in a predetermined pattern which are adapted to be in physical contact with the element and to provide a controlled standoff therefrom which defines a uniform adhesive bond line. The heat sink also preferably provides a means for reducing the temperature gradient between the center pins and peripheral pins which results from the center of the integrated circuit typically being hotter than the outer areas. For a preferred embodiment, this is acomplished by having a dish-shaped base which provides improved heat transfer to the outer pins.
Inventors
- 👤 Victor Lorenzetti
- 👤 Manuel Pontes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:20
CPC Classifications
H; H10; H10W; H10W40/00; H10W40/20; H10W40/22; H10W40/226; H10W40/228
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
127 words
A heat sink for an element to be cooled comprising: a base; a plurality of pins extending substantially perpendicular to the base, said pins being arranged in a predetermined pattern; and at least one projection integral with said base, extending from the side thereof adjacent the element to be cooled and having an area for the projection surface parallel to the side from which it extends and adapted to make thermal contact with the element to be cooled which is sufficient to provide good thermal transfer between the heat sink and the element while maintaining the area of contact to a fraction of the base area sufficiently small to assure that uneven thermal expansion between the heat sink and element does not cause damage to the element.
Claim 2
Dependent Claim
127 words
A heat sink for an element to be cooled comprising: a base; a plurality of pins extending substantially perpendicular to the base, said pins being arranged in a predetermined pattern; and at least one projection integral with said base, extending from the side thereof adjacent the element to be cooled and having an area for the projection surface parallel to the side from which it extends and adapted to make thermal contact with the element to be cooled which is sufficient to provide good thermal transfer between the heat sink and the element while maintaining the area of contact to a fraction of the base area sufficiently small to assure that uneven thermal expansion between the heat sink and element does not cause damage to the element.
Claim 3
Dependent Claim
20 words
A heat sink as claimed in claim 1 wherein said pin pattern is symmetrical, whereby the heat sink is omnidirectional.
Claim 4
Dependent Claim
14 words
A heat sink as claimed in claim 1 wherein said pin pattern is staggered.
Claim 5
Dependent Claim
25 words
A heat sink as claimed in claim 1 wherein said projection is a center pedestal, said pedestal being adapted to be bonded to the element.
Claim 6
Dependent Claim
25 words
A heat sink as claimed in claim 1 wherein said projections form a predetermined pattern and are adapted to be in contact with the element.
Claim 7
Dependent Claim
53 words
A heat sink as claimed in claim 5 wherein said heat sink is bonded to the element by an adhesive bond, there being a desired thickness for said bond; and wherein said projections are of a height substantially equal to the desired adhesive bond thickness, providing a controlled space standoff for the adhesive.
Claim 8
Dependent Claim
27 words
A heat sink as claimed in claim 1 wherein said base, at least one projection and pins are formed as a single, substantially homogeneous piece of material.
Claim 9
Dependent Claim
14 words
A heat sink as claimed in claim 7 wherein said material is a metal.
Claim 10
Dependent Claim
17 words
A heat sink as claimed in claim 8 wherein said heat sink is formed by being cast.
Claim 11
Dependent Claim
25 words
A heat sink as claimed in claim 9 wherein the metal selected as the material is a metal which is particularly adapted to be cast.
Claim 12
Dependent Claim
73 words
A heat sink as claimed in claim 1 wherein said heat sink has a center portion and outer portions, the center portion being adapted to be in contact with a portion of the element which is normally hotter than the portions in contact with the outer areas of the heat sink; and wherein said heat sink includes means for reducing the resulting temperature gradient between the pins in said center and outer portions.
Claim 13
Dependent Claim
36 words
A heat sink as claimed in claim 11 wherein said gradient reducing means includes said base being shaped to provide an improved heat conduction path to the pins extending from the outer portions of the base.
Claim 14
Dependent Claim
28 words
A heat sink as claimed in claim 12 wherein the thickness of the base increases in a predetermined way from the center to the periphery of the base.
Claim 15
Dependent Claim
13 words
A heat sink as claimed in claim 13 wherein said base is dish-shaped.
Claim 16
Dependent Claim
64 words
A heat sink as claimed in claim 14 wherein the height of the pins is greatest in said center portion where said base is of least thickness and decreases for pins toward the periphery which project from portions of the base of increasing thickness, permitting the tops of the pins to be in a common plane parallel to the plane of the base bottom.
Claim 17
Dependent Claim
27 words
A heat sink as claimed in claim 1 wherein the center pin is a post, the diameter of the post being greater than that of the pins.
Claim 18
Dependent Claim
21 words
A heat sink as claimed in claim 1 wherein the heat sink is particularly adapted for use with integrated circuit elements.
Claim 19
Dependent Claim
136 words
A heat sink for an element to be cooled which element has at least one portion which is hotter than other portions of the element comprising: a base having a central portion and peripheral portions, the base being adapted to be in thermal contact with the element to be cooled with the center portion of the base thermally contacting the hotter portion of said element, the thickness of said base being least in said center portion and increasing in a predetermined way from the center portion to the periphery of the base; a plurality of pins extending substantially perpendicular to the base, said pins being arranged in a predetermined pattern; and the varying thickness of the base being operative to reduce the temperature gradient between pins over said center portion and pins over said peripheral portions.
Claim 20
Dependent Claim
136 words
A heat sink for an element to be cooled which element has at least one portion which is hotter than other portions of the element comprising: a base having a central portion and peripheral portions, the base being adapted to be in thermal contact with the element to be cooled with the center portion of the base thermally contacting the hotter portion of said element, the thickness of said base being least in said center portion and increasing in a predetermined way from the center portion to the periphery of the base; a plurality of pins extending substantially perpendicular to the base, said pins being arranged in a predetermined pattern; and the varying thickness of the base being operative to reduce the temperature gradient between pins over said center portion and pins over said peripheral portions.
Claim 21
Dependent Claim
13 words
A heat sink as claimed in claim 18 wherein said base is dish-shaped.
Claim 22
Dependent Claim
66 words
A heat sink as claimed in claim 19 wherein the height of the pins is greatest for pins extending from the center of the base where the base is of least thickness and decreases for pins extending from peripheral portions of the base of increasing thickness, permitting the tops of the pins to be in a common plane parallel to the plane of the base bottom.
Claim 23
Dependent Claim
23 words
A heat sink as claimed in claim 18 wherein said base and pins are formed as a single substantially homogeneous piece of material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-02-05 | 1993-08-07 | 1994-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-05 | 1997-08-07 | 1998-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-05 | 2001-08-07 | 2002-02-06 | $7700.00 | Window Closed / Lapsed |