US3860949A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor mounting devices made by soldering flat surfaces to each other
Assignee: RCA Corp
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Filing: 1973-09-12
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Granted: 1975-01-14
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Expires: 1993-09-12
Abstract
Abstract A flat surface of a semiconductor chip is soldered to a relatively larger flat surface of a heat sink by forming a plurality of closely spaced grooves in the flat surface of the heat sink, coating the flat surfaces of the chip and the heat sink with nickel, disposing solder between the coated surfaces of the chip and the heat sink, and heating the surfaces until the solder melts. The grooves in the heat sink prevent the entrapment of gas bubbles between the chip and the heat sink, thereby providing good thermal conductivity and a relatively low electrical resistance between the chip and the heat sink.
Inventors
- 👤 Alvin John Stoeckert
- 👤 James Martin Hunt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:58
CPC Classifications
H; H10; H10W; H10W40/00; H10W40/10; B; B23; B23K; B23K1/00; B23K1/20; H10D; H10D62/00; H10D62/10; H10D62/117; B23K2101/00; B23K2101/36; B23K2101/40; H10W72/00; H10W72/071; H10W72/073; H10W72/07331; H10W72/07336; H10W72/30; H10W72/321; H10W72/322; H10W72/351; H10W72/352; H10W90/00; H10W90/701; H10W90/731; H10W90/736
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
87 words
In a semiconductor device wherein a first flat surface of a semiconductor chip is joined to a second flat surface of a metal by a fusible bonding material, the improvement comprising: a plurality of non-intersecting grooves in said second flat surface adjacent said semiconductor chip and extending beyond the periphery thereof, said grooves being substantially parallel to each other, each of said grooves having A depth of between about 1 and 3 mils, and said grooves being spaced between about 10 and 40 mils from each other.
Claim 2
Dependent Claim
87 words
In a semiconductor device wherein a first flat surface of a semiconductor chip is joined to a second flat surface of a metal by a fusible bonding material, the improvement comprising: a plurality of non-intersecting grooves in said second flat surface adjacent said semiconductor chip and extending beyond the periphery thereof, said grooves being substantially parallel to each other, each of said grooves having A depth of between about 1 and 3 mils, and said grooves being spaced between about 10 and 40 mils from each other.
Claim 3
Dependent Claim
28 words
A semiconductor device as described in claim 1 wherein: each of said grooves is substantially V-shaped and defines an angle of between 30* and 90* at its vertex.
Claim 4
Dependent Claim
44 words
A semiconductor device as described in claim 1 wherein: said flat surface of said semiconductor chip has a coating of nickel thereon, said fusible bonding material comprises solder, said metal comprises a heat sink, and said heat sink has a coating of nickel thereon.
Claim 5
Dependent Claim
67 words
A semiconductor device as described in claim 3 wherein: said device comprises, in addition, a header of metal having a flat surface formed with a plurality of grooves therein, and said heat sink has a lower flat surface bonded to the flat surface of said header with a fusible bonding material, said grooves in said header being adjacent said heat sink and extending beyond the periphery thereof.
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) | 1978-01-13 | 1978-07-15 | 1979-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-13 | 1982-07-15 | 1983-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-13 | 1986-07-15 | 1987-01-14 | $7700.00 | Window Closed / Lapsed |