US3745422A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power semi-conductor device mountable on either its top or bottom surface
Assignee: Motorola Solutions Inc
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Filing: 1972-03-07
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Granted: 1973-07-10
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Expires: 1992-03-07
Abstract
Abstract A metal package, suitable for housing power transistors and other power semiconductors is disclosed. The metal package is fabricated to transfer heat from the transistor to either a top surface or to a bottom surface enabling the mounting of the package containing the power transistor or power semiconductor to a mounting surface adjacent either the top or the bottom thereof.
Inventors
- 👤 R Carnes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:26
CPC Classifications
H; H10; H10W; H10W76/00; H10W76/10; H10W76/12; H10W76/13; H10W76/132; H10W40/00; H10W40/10; H10W72/00; H10W72/50; H10W72/531; H10W72/5363; H10W72/5366; H10W90/00; H10W90/701; H10W90/751; H10W90/753; H10W90/754
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
149 words
A power semiconductor device having at least one terminal extending therefrom and having a metallic, heat-conductive base with a flat bottom surface and with a cavity having a side wall and lower surface, extending partially therethrough from the top surface thereof, and at least one mounting aperture completely therethrough, the improvement comprising: a. an annular shoulder, integral with the base, recessed below the top surface of the base, directly above and surrounding the sidewall of the cavity; b. a semiconductor die, affixed to the lower surface of the cavity; and c. a flat cap, welded to the annular shoulder, to form a relatively flat top surface, essentially parallel to the bottom surface, for selective mounting to a mounting plate with either the top surface or the bottom surface abutting the mounting plate, the mounting being accomplished by a mounting screw passing through the mounting aperture into the mounting plate.
Claim 2
Dependent Claim
149 words
A power semiconductor device having at least one terminal extending therefrom and having a metallic, heat-conductive base with a flat bottom surface and with a cavity having a side wall and lower surface, extending partially therethrough from the top surface thereof, and at least one mounting aperture completely therethrough, the improvement comprising: a. an annular shoulder, integral with the base, recessed below the top surface of the base, directly above and surrounding the sidewall of the cavity; b. a semiconductor die, affixed to the lower surface of the cavity; and c. a flat cap, welded to the annular shoulder, to form a relatively flat top surface, essentially parallel to the bottom surface, for selective mounting to a mounting plate with either the top surface or the bottom surface abutting the mounting plate, the mounting being accomplished by a mounting screw passing through the mounting aperture into the mounting plate.
Claim 3
Dependent Claim
43 words
The semiconductor device of claim 1 wherein the bottom surface of the cavity is recessed, the invention further comprising: d. a metallic insert fixed within the recess, having a substantially greater thermal conductivity than the base and having the semiconductor die affixed thereto.
Claim 4
Dependent Claim
24 words
The semiconductor device of claim 2 wherein the base is aluminum or an aluminum alloy and the insert is copper or a copper alloy.
Claim 5
Dependent Claim
15 words
A semiconductor device of claim 1 wherein the base is copper or a copper alloy.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-09 | 1977-01-08 | 1977-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-09 | 1981-01-08 | 1981-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-09 | 1985-01-08 | 1985-07-10 | $7700.00 | Window Closed / Lapsed |