US4451540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for packaging of electronic circuits
Assignee: ISOTRONICS Inc NEW BEDFORD MA A DE CORP
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Filing: 1982-08-30
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Granted: 1984-05-29
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Expires: 2002-08-30
Abstract
Abstract A brazing technique is described for providing a standard flat pack with a Thermkon base brazed to a Kovar frame through the utilization of an intermediary ring of high thermal conductivity material which prevents flashing onto the Thermkon base. Brazing is accomplished either in a one-step process in which the parts with the intermediary ring are brazed together all at one time with a single heat treatment, or in a two-step process in which the intermediary ring is first brazed to the frame. In a subsequent step, the frame with the intermediary ring brazed thereto, is brazed to the Thermkon base. In either process, the high thermal conductivity of the intermediary ring permits the ring to quickly reach brazing temperature for minimizing flashing.
Inventors
- 👤 Phillips C. Baird
- 👤 Raymond J. Duff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:28
CPC Classifications
B; B23; B23K; B23K1/00; B23K1/19; H; H10; H10W; H10W76/00; H10W76/10; H10W76/12; H10W76/13; H10W76/134; H10W76/60; H10W95/00; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
173 words
A flat pack carrier for housing electronic components comprising a sandwich of a frame of nickel, cobalt, and iron, a first braze layer, a copper ring, a second braze layer, and a base of an alloy of tungsten and copper, said flat pack carrier having been formed in a brazing step which includes the steps of providing a sandwich structure of a frame, a braze, a ring, a braze and a copper tungsten alloy base, raising the temperature of said sandwich structure to the melting point of the braze having the highest melting point, and cooling said sandwich structure below the melting point of the braze having the lowest melting point such that the frame is brazed to the ring, such that the ring is brazed to the base, and such that the braze does not flash out over the base during brazing due to the higher thermal conductivity of said ring and base and because the base and ring reach the same temperature at substantially the same time during the brazing process.
Claim 2
Dependent Claim
173 words
A flat pack carrier for housing electronic components comprising a sandwich of a frame of nickel, cobalt, and iron, a first braze layer, a copper ring, a second braze layer, and a base of an alloy of tungsten and copper, said flat pack carrier having been formed in a brazing step which includes the steps of providing a sandwich structure of a frame, a braze, a ring, a braze and a copper tungsten alloy base, raising the temperature of said sandwich structure to the melting point of the braze having the highest melting point, and cooling said sandwich structure below the melting point of the braze having the lowest melting point such that the frame is brazed to the ring, such that the ring is brazed to the base, and such that the braze does not flash out over the base during brazing due to the higher thermal conductivity of said ring and base and because the base and ring reach the same temperature at substantially the same time during the brazing process.
Claim 3
Independent Claim
90 words
A method of preventing flashing in an all metal flat pack carrier when a frame having a lower thermal conductivity is brazed to a base having a higher thermal conductivity comprising the steps of positioning a member having a thermal conductivity greater than that of the part having the lower thermal conductivity between the parts and brazing parts and member together, said brazing step including the steps of providing a sandwich structure of said frame, a first layer of braze, said member, a second layer of braze, and said base.
Claim 4
Independent Claim
90 words
A method of preventing flashing in an all metal flat pack carrier when a frame having a lower thermal conductivity is brazed to a base having a higher thermal conductivity comprising the steps of positioning a member having a thermal conductivity greater than that of the part having the lower thermal conductivity between the parts and brazing parts and member together, said brazing step including the steps of providing a sandwich structure of said frame, a first layer of braze, said member, a second layer of braze, and said base.
Claim 5
Dependent Claim
108 words
The method of claim 2 wherein said brazing step includes the steps of providing a first sandwich structure of one part, a first layer of braze and said member, subjecting said first sandwich structure to a temperature equal to that at which said first layer of braze melts, cooling said first sandwich structure below the first braze layer melting point, providing a second sandwich structure of said first sandwich structure, a second layer of braze, and the other part, subjecting said second sandwich structure to a temperature at which said second layer of braze melts, and cooling said second sandwich structure below the second braze layer melting point.
Claim 6
Dependent Claim
11 words
The method of claim 3 wherein said temperatures are the same.
Claim 7
Dependent Claim
16 words
The method of claim 2 wherein said lower thermal conductivity part is a glass sealing alloy.
Claim 8
Dependent Claim
18 words
The method of claim 2 wherein said higher thermal conductivity part is a material containing tungsten and copper.
Claim 9
Dependent Claim
10 words
The method of claim 2 wherein said member is copper.
Claim 10
Dependent Claim
39 words
The method of claim 2 wherein said lower thermal conductivity part is a material containing nickel, cobalt, and iron, wherein said member is nickel-clad copper, and wherein said higher thermal conductivity part is nickel-clad material containing tungsten and copper.
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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) | 1987-05-29 | 1987-11-28 | 1988-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-29 | 1991-11-28 | 1992-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-29 | 1995-11-28 | 1996-05-29 | $7700.00 | Window Closed / Lapsed |