US4025997A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic mounting and heat sink device
Assignee: ITT Inc
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Filing: 1975-12-23
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Granted: 1977-05-31
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Expires: 1995-12-23
Abstract
Abstract This relates to a multi-layer composite metallic sheet having a predetermined coefficient of thermal expansion for use as a heat sink and mounting arrangement when bonded to a ceramic substrate. Since copper has a coefficient of thermal expansion greater than that of ceramic and molybdenum has a coefficient of thermal expansion less than that of ceramic, layers of copper and molybdenum can be combined to provide a composite having a coefficient of thermal expansion equal to that of ceramic. To avoid a bimetallic effect, a core layer of a fused metal is sandwiched between two outer layers of the second metal.
Inventors
- 👤 Jeffrey Gernitis
- 👤 Bruno Butti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:32
CPC Classifications
H; H10; H10W; H10W40/00; H10W40/20; H10W40/25; H10W40/255; B; B32; B32B; B32B15/00; B32B15/01; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12771; Y10T428/12806; Y10T428/12826
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
84 words
An apparatus for mounting and dissipating heat from a fracturable substrate coupled thereto, said substrate having a first coefficient of thermal expansion comprising: a first layer of a first material having a second coefficient of thermal expansion; and second and third layers of a second material each bonded to an outer opposite surface of said first layer, said second material having a third coefficient of thermal expansion, said first coefficient of thermal expansion intermediate that of said second and third coefficients of thermal expansion.
Claim 2
Independent Claim
84 words
An apparatus for mounting and dissipating heat from a fracturable substrate coupled thereto, said substrate having a first coefficient of thermal expansion comprising: a first layer of a first material having a second coefficient of thermal expansion; and second and third layers of a second material each bonded to an outer opposite surface of said first layer, said second material having a third coefficient of thermal expansion, said first coefficient of thermal expansion intermediate that of said second and third coefficients of thermal expansion.
Claim 3
Dependent Claim
13 words
An apparatus according to claim 1 wherein said fracturable material is a ceramic.
Claim 4
Dependent Claim
18 words
An apparatus according to claim 2 wherein said first material is copper and said second material is molybdenum.
Claim 5
Dependent Claim
18 words
An apparatus according to claim 2 wherein said first material is molybdenum and said second material is copper.
Claim 6
Dependent Claim
16 words
An apparatus according to claim 2 wherein said second and third layers are of equal thickness.
Claim 7
Dependent Claim
17 words
An apparatus according to claim 5 wherein said heat sink is mounted on a printed circuit board.
Claim 8
Dependent Claim
26 words
An apparatus according to claim 6 wherein the resultant coefficient of thermal expansion of said heat sink is substantially equal to that of said ceramic substrate.
Claim 9
Dependent Claim
27 words
An apparatus according to claim 3 wherein said first layer has a thickness of 0.016" and said second and third layers each have a thickness of 0.023".
Claim 10
Dependent Claim
27 words
An apparatus according to claim 4 wherein said first layer has a thickness of 0.046" and said second and third layers each have a thickness of 0.008".
Claim 11
Dependent Claim
175 words
A tri-layer composite metallic sheet for use as a heat sink for a fracturable material having a predetermined coefficient of thermal expansion comprising: a first layer of a first material having a first coefficient of thermal expansion; and second and third layers of a second material each bonded to opposite surfaces of said first layer, said second material having a second predetermined coefficient of thermal expansion wherein the coefficient of thermal expansion of said fracturable material is intermediate the coefficients of thermal expansion of said first and second materials and wherein the thickness of said first layer X 1 and the total thickness of said second and third layers X 2 are governed by the equation ##EQU2## where α 3 is the coefficient of thermal expansion of said fracturable material, α 1 is the coefficient of thermal expansion of said first material, α 2 is the coefficient expansion of said second material, E 1 is the modulus of elasticity of said first material and E 2 is the modulus of elasticity of said second material.
Claim 12
Dependent Claim
175 words
A tri-layer composite metallic sheet for use as a heat sink for a fracturable material having a predetermined coefficient of thermal expansion comprising: a first layer of a first material having a first coefficient of thermal expansion; and second and third layers of a second material each bonded to opposite surfaces of said first layer, said second material having a second predetermined coefficient of thermal expansion wherein the coefficient of thermal expansion of said fracturable material is intermediate the coefficients of thermal expansion of said first and second materials and wherein the thickness of said first layer X 1 and the total thickness of said second and third layers X 2 are governed by the equation ##EQU2## where α 3 is the coefficient of thermal expansion of said fracturable material, α 1 is the coefficient of thermal expansion of said first material, α 2 is the coefficient expansion of said second material, E 1 is the modulus of elasticity of said first material and E 2 is the modulus of elasticity of said second material.
Claim 13
Dependent Claim
26 words
A tri-layer composite metallic sheet according to claim 10 wherein said fracturable material is ceramic, said first material is copper, and said second material is molybdenum.
Claim 14
Dependent Claim
19 words
A tri-layer composite metallic sheet according to claim 10 wherein said second and third layers are of equal thickness.
Claim 15
Dependent Claim
19 words
A tri-layer composite metallic sheet according to claim 10 wherein said heat sink is fixedly coupled to said substrate.
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) | 1980-05-30 | 1980-11-29 | 1981-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-30 | 1984-11-29 | 1985-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-30 | 1988-11-29 | 1989-05-31 | $7700.00 | Window Closed / Lapsed |