US4824009A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for braze attachment of electronic package members
Assignee: International Business Machines Corp
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Filing: 1981-12-31
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Granted: 1989-04-25
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Expires: 2001-12-31
Abstract
Abstract In the process of braze attachment of electronic package members, such as attaching metallic coated connector pins to a multilayer ceramic substrate, contact areas of the substrate are formed by sequential coatings of molybdenum and nickel, which are heated to diffuse the nickel. A pure gold paste is applied by screen printing, for example, followed by the step of firing to burn out the paste binder and to sinter the pure gold particles onto a dense low porosity structure. The sintering operation converts the Ni film into a continuous Au-Ni solid solution. During pin braze, Ni-Sn intermetallics are dispersed in a gold rich matrix of the Au-Ni solid solution.
Inventors
- 👤 Raj N. Master
- 👤 Marvin S. Pittler
- 👤 Paul A. Totta
- 👤 Norman G. Ainslie
- 👤 Paul H. Palmateer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:31
CPC Classifications
H; H10; H10W; H10W90/00; H10W90/701; H10W70/00; H10W70/099; H05; H05K; H05K3/00; H05K3/22; H05K3/24; H05K3/245; H05K3/30; H05K3/32; H05K3/34; H05K3/346
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
110 words
A process for joining a metallic coated conductive connector pin to a ceramic substrate comprising the steps of: depositing a layer of molybdenum on a surface of said substrate; depositing a film of nickel on said molybdenum layer; heating said assembly at a specified temperature for diffusing a portion of said nickel into said molybdenum layer; applying a layer of substantially pure gold to said nickel film followed by sintering said gold, to combine it with undiffused portions of said nickel to form a continuous gold-nickel solid solution; and brazing said connector pin with a gold-tin brazing compound via said gold-nickel solid solution to join said pin to said substrate.
Claim 2
Dependent Claim
110 words
A process for joining a metallic coated conductive connector pin to a ceramic substrate comprising the steps of: depositing a layer of molybdenum on a surface of said substrate; depositing a film of nickel on said molybdenum layer; heating said assembly at a specified temperature for diffusing a portion of said nickel into said molybdenum layer; applying a layer of substantially pure gold to said nickel film followed by sintering said gold, to combine it with undiffused portions of said nickel to form a continuous gold-nickel solid solution; and brazing said connector pin with a gold-tin brazing compound via said gold-nickel solid solution to join said pin to said substrate.
Claim 3
Dependent Claim
20 words
A process as in claim 1, wherein said applied gold is a gold paste comprising pure gold in a binder.
Claim 4
Dependent Claim
14 words
A process as in claim 2, wherein said gold paste is applied by screening.
Claim 5
Dependent Claim
19 words
A process as in claim 2, including the step of firing said gold paste to burn out said binder.
Claim 6
Dependent Claim
21 words
A process as in claim 1, wherein said gold is sintered at a temperature in the range of 680° C.-850° C.
Claim 7
Dependent Claim
15 words
A process as in claim 1, wherein said connector is a nickel plated Kovar pin.
Claim 8
Dependent Claim
19 words
A process as in claim 1, wherein said connector pin is coated with a metal of gold-nickel or gold-palladium.
Claim 9
Dependent Claim
34 words
The process as in claim 1 wherein said diffusion employs a portion of said nickel at its interface with molybdenum with said gold forming a solid solution with the remaining portion of said nickel.
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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) | 1992-04-24 | 1992-10-24 | 1993-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-24 | 1996-10-24 | 1997-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-24 | 2000-10-24 | 2001-04-25 | $7700.00 | Window Closed / Lapsed |