Patent US2018400A successfully refreshed from Google Patents.
Patent US3780795A successfully refreshed from Google Patents.
US3780795A
Expired / Lapsed
US
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Multilayer heat sink
Assignee: RCA Corp
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Filing: 1972-06-19
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Granted: 1973-12-25
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Expires: 1992-06-19
Abstract
Abstract An improved heat sink comprises an integral metallic structure, having upper and lower layers of different metals, respectively, fixed to each other to provide a common interface. The lower layer has a greater coefficient of thermal expansion than the upper layer. An upwardly extending dimpled portion of the upper layer is formed by a dent that extends upwardly from the common interface. When the heat sink is heated by a heat-producing device mounted on the surface of the dimpled portion, the lower layer tends to expand in an opposite direction to that of the dimpled portion of the upper layer, so that the dimpled portion is in compression, thereby limiting the amount of thermal expansion and distortion that would normally occur at the surface of the dimpled portion.
Inventors
- 👤 A Arnold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:23
CPC Classifications
H; H10; H10W; H10W40/00; H10W40/20; H10W40/25; H10W40/255; H10W40/60; H10W40/611; H10W40/231; H10W40/235
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
93 words
In an assembly of the type comprising a heat-producing device mounted on a heat sink, the improvement comprising said heat sink comprising a multilayered structure of different metals which, when heated, tend to expand differently and to produce compressive forces resulting in a lesser expansion on a portion of one surface of said heat sink with respect to other surface portions of said heat sink, and said device being mounted on said portion, whereby to minimize stress between said device and said heat sink due to differences in their linear coefficients of expansion.
Claim 2
Dependent Claim
93 words
In an assembly of the type comprising a heat-producing device mounted on a heat sink, the improvement comprising said heat sink comprising a multilayered structure of different metals which, when heated, tend to expand differently and to produce compressive forces resulting in a lesser expansion on a portion of one surface of said heat sink with respect to other surface portions of said heat sink, and said device being mounted on said portion, whereby to minimize stress between said device and said heat sink due to differences in their linear coefficients of expansion.
Claim 3
Dependent Claim
52 words
In an assembly of the type described in claim 1, said multilayered structure comprises two layers of dissimilar metals, fixed to each other, having a common interface and different coefficients of linear expansion, and said device is mounted on the layer having the lower coefficient of linear expansion of said two layers.
Claim 4
Dependent Claim
56 words
In an assembly of the type described in claim 2, a first layer of said two layers has said lower coefficient of linear expansion, a raised dimpled portion in said first layer extends from a dent in said first layer at said interface, and said device is mounted on a surface of said raised dimpled portion.
Claim 5
Dependent Claim
113 words
An assembly comprising a heat-producing device and a laminated heat sink including first and second metal members bonded together, said first metal member being attached to said device by a bond and having a greater thermal expansion than said device, whereby said bond is tended to be stessed when said assembly is heated, said second metal member cooperating with said first metal member to produce a bimetal bending action when said heat sink is heated, which bending compressively stresses the surface of said first metal member to which said device is bonded, whereby the bending compression partially counteracts the thermal expansion of said first metal member to minimize the stress in said bond.
Claim 6
Dependent Claim
113 words
An assembly comprising a heat-producing device and a laminated heat sink including first and second metal members bonded together, said first metal member being attached to said device by a bond and having a greater thermal expansion than said device, whereby said bond is tended to be stessed when said assembly is heated, said second metal member cooperating with said first metal member to produce a bimetal bending action when said heat sink is heated, which bending compressively stresses the surface of said first metal member to which said device is bonded, whereby the bending compression partially counteracts the thermal expansion of said first metal member to minimize the stress in said bond.
Claim 7
Dependent Claim
42 words
An assembly as described in claim 4, wherein said first and second metal members have a common interface, said first metal member has a raised portion extending from said interface, and said device is bonded to the surface of said raised portion.
Claim 8
Dependent Claim
108 words
In an electronic assembly of the type comprising a heat-pRoducing device mounted on a heat sink, the improvement comprising said heat sink comprising a first layer of a first metal that tends to bend in an arc in a direction around said device when heated by said device, a second layer of a second metal, fixed to said first layer and having a portion that tends to bend in an arc in a direction opposite to that of said first layer when heated by said device, whereby to oppose the bending of said first layer, and said device being mounted on said second layer intermediate the ends thereof.
Claim 9
Dependent Claim
108 words
In an electronic assembly of the type comprising a heat-pRoducing device mounted on a heat sink, the improvement comprising said heat sink comprising a first layer of a first metal that tends to bend in an arc in a direction around said device when heated by said device, a second layer of a second metal, fixed to said first layer and having a portion that tends to bend in an arc in a direction opposite to that of said first layer when heated by said device, whereby to oppose the bending of said first layer, and said device being mounted on said second layer intermediate the ends thereof.
Claim 10
Dependent Claim
41 words
In an electronic assembly of the type described in claim 6, wherein: said first and said second layers have a common interface, said second layer has a raised portion, and said device is mounted on a surface of said raised portion.
Claim 11
Dependent Claim
111 words
A multilayer heat sink for receiving a heat-producing device thereon, said heat sink comprising: a metallic structure comprising a first layer of a first metal, and a second layer of a second metal fixed to said first layer and having a common interface therewith, said second metal having a greater coefficient of thermal expansion than that of said first metal, the product of the thickness of said first layer and its modulus of elasticity being within + or - 60% of the product of the thickness of said second layer and its modulus of elasticity, and a surface site intermediate ends of said first layer for receiving said heat-producing device thereon.
Claim 12
Dependent Claim
111 words
A multilayer heat sink for receiving a heat-producing device thereon, said heat sink comprising: a metallic structure comprising a first layer of a first metal, and a second layer of a second metal fixed to said first layer and having a common interface therewith, said second metal having a greater coefficient of thermal expansion than that of said first metal, the product of the thickness of said first layer and its modulus of elasticity being within + or - 60% of the product of the thickness of said second layer and its modulus of elasticity, and a surface site intermediate ends of said first layer for receiving said heat-producing device thereon.
Claim 13
Dependent Claim
52 words
A multilayer heat sink for receiving a heat-producing device thereon, as described in claim 8, wherein: the product of the thickness of said first layer and its modulus of elasticity is within + or - 20 percent of the product of the thickness of said second layer and its modulus of elasticity.
Claim 14
Dependent Claim
41 words
A multilayer heat sink for receiving a heat-producing device thereon, as described in claim 8, wherein: said first metal has a raised portion intermediate opposite ends of said first layer, and said surface site is a surface of said raised portion.
Claim 15
Dependent Claim
108 words
A multilayer heat sink for receiving a heat-producing device thereon, said heat sink comprising: a metallic structure comprising a first layer of a first metal, and a second layer of a second metal fixed to said first layer and having a common interface therewith, said second metal having a greater coefficient of thermal expansion than that of said first metal, said first layer having a dimpled portion extending outwardly from said interface, a second portion of said second layer, extending to said dimpled portion of said first layer, at said interface, and said dimpled portion of said first layer having a surface site for receiving said heat-producing device.
Claim 16
Dependent Claim
108 words
A multilayer heat sink for receiving a heat-producing device thereon, said heat sink comprising: a metallic structure comprising a first layer of a first metal, and a second layer of a second metal fixed to said first layer and having a common interface therewith, said second metal having a greater coefficient of thermal expansion than that of said first metal, said first layer having a dimpled portion extending outwardly from said interface, a second portion of said second layer, extending to said dimpled portion of said first layer, at said interface, and said dimpled portion of said first layer having a surface site for receiving said heat-producing device.
Claim 17
Dependent Claim
52 words
A multilayered heat sink for receiving a heat-producing device thereon, as described in claim 11, wherein: the product of the thickness of said first layer and its modulus of elasticity is within + or - 20 percent of the product of the thickness of said second layer and its modulus of elasticity.
Claim 18
Dependent Claim
52 words
A multilayer heat sink for receiving a heat-producing device thereon, as described in claim 11, wherein: the product of the thickness of said first layer and its modulus of elasticity is within + or - 60 percent of the product of the thickness of said second layer and its modulus of elasticity.
Claim 19
Dependent Claim
61 words
A multilayer heat sink for receiving a heat-producing device thereon, as described in claim 11, wherein: said second portion of said second layer, at said interface, extends to said dimpled portion of said first layer a distance of between 15 percent and 35 percent of the total thickness of said metal structure adjacent to said dimpled and said second portions thereof.
Claim 20
Dependent Claim
60 words
A multilayered heat sink for receiving a heat-producing device thereon, as described in claim 11, wherein: said second portion of said second layer, at said interface, extends to said dimpled portion of said first layer a distance of bEtween 1 percent and 70 percent of the total thickness of said metal structure adjacent said dimpled and said second portions thereof.
Claim 21
Dependent Claim
45 words
A multilayer heat sink for receiving a heat-producing device thereon, as described in claim 11, wherein: said dimpled portion has a base with an average diameter of between 50 percent and 150 percent of the average diameter of the mounting surface of said heat-producing device.
Claim 22
Dependent Claim
45 words
A multilayer heat sink for receiving a heat-producing device thereon, as described in claim 11, wherein: said dimpled portion has a base with an average diameter of between 20 percent and 300 percent of the average diameter of the mounting surface of said heat-producing device.
Claim 23
Dependent Claim
32 words
A multilayer heat sink for receiving a heat-producing device thereon, as described in claim 11, wherein: said surface site of said dimpled portion for receiving said heat-producing device is a convex surface.
References Cited (Backward Citations)
US3249680A
Cited
US3476177A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |