Patent US5121871A successfully refreshed from Google Patents.
US5121871A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solder extrusion pressure bonding process and bonded products produced thereby
Assignee: United States Department of Energy
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Filing: 1990-04-20
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Granted: 1992-06-16
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Expires: 2010-04-20
Abstract
Abstract Production of soldered joints which are highly reliable and capable of surviving 10,000 thermal cycles between about -40° C. and 110° C. Process involves interposing a thin layer of a metal solder composition between the metal surfaces of members to be bonded and applying heat and up to about 1000 psi compression pressure to the superposed members, in the presence of a reducing atmosphere, to extrude the major amount of the solder composition, contaminants including fluxing gases and air, from between the members being bonded, to form a very thin, strong intermetallic bonding layer having a thermal expansion tolerant with that of the bonded members.
Inventors
- 👤 Leonard C. Beavis
- 👤 Maurice M. Karnowsky
- 👤 Frederick G. Yost
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:00
CPC Classifications
H; H10; H10W; H10W99/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
133 words
A process for producing a strong, creep-resistant, thin intermetallic bonding layer, said process comprising: forming a stack by superposing at least two members having relatively smooth flat metallic surfaces to be bonded; interposing between said surfaces a relatively thin layer of a soft solder composition containing at least one metal which is capable of forming an intermetallic compound by reaction with one or more of the metals of the surfaces being bonded; heating said stack to melt said solder layer in the presence of a reducing gas atmosphere; simultaneously compressing said stack under sufficient pressure to completely wet said surfaces and to extrude the major volume of solder from between said metallic surfaces along with contaminants; and cooling said stack to produce bonded members united by a strong, creep-resistant thin intermetallic bonding layer.
Claim 2
Dependent Claim
133 words
A process for producing a strong, creep-resistant, thin intermetallic bonding layer, said process comprising: forming a stack by superposing at least two members having relatively smooth flat metallic surfaces to be bonded; interposing between said surfaces a relatively thin layer of a soft solder composition containing at least one metal which is capable of forming an intermetallic compound by reaction with one or more of the metals of the surfaces being bonded; heating said stack to melt said solder layer in the presence of a reducing gas atmosphere; simultaneously compressing said stack under sufficient pressure to completely wet said surfaces and to extrude the major volume of solder from between said metallic surfaces along with contaminants; and cooling said stack to produce bonded members united by a strong, creep-resistant thin intermetallic bonding layer.
Claim 3
Dependent Claim
22 words
Process according to claim 1 in which one of said at least two members comprises a ceramic body having a metal-coated surface.
Claim 4
Dependent Claim
15 words
Process according to claim 2 in which said member is a vacuum metallized silicon body.
Claim 5
Dependent Claim
22 words
A process according to claim 3 in which the metal coating of said vacuum metallized silicon body member is comprised of silver.
Claim 6
Dependent Claim
21 words
Process according to claim 2 in which the other of said at least two members comprises a copper heat sink layer.
Claim 7
Dependent Claim
22 words
A process according to claim 1 in which said at least one of said metals of said soft solder composition comprises tin.
Claim 8
Dependent Claim
20 words
Process according to claim 1 which comprises heating said stack to a temperature between about 300° C. and 400° C.
Claim 9
Dependent Claim
18 words
Process according to claim 1, in which said pressure is between about 40 psi and about 100 psi.
Claim 10
Dependent Claim
12 words
Process according to claim 8 in which said pressure is 60±5 psi.
Claim 11
Dependent Claim
15 words
The process of claim 1 wherein said stack is compressed at up to 1000 psi.
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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) | 1995-06-16 | 1995-12-16 | 1996-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-16 | 1999-12-16 | 2000-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-16 | 2003-12-16 | 2004-06-16 | $7700.00 | Window Closed / Lapsed |