US3735208A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal fatigue lead-soldered semiconductor device
Assignee: RCA Corp
•
Filing: 1971-08-26
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Granted: 1973-05-22
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Expires: 1991-08-26
Abstract
Abstract The device includes a semiconductor die joined to a thermally conductive substrate with a solder having a high lead content. An enclosure surrounds the die and is sealed to the substrate. A substantially nonoxidizing atmosphere is provided within the enclosure.
Inventors
- 👤 A Roswell
- 👤 G Clymer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:44
CPC Classifications
H; H10; H10W; H10W76/00; H10W76/10; H10W76/12; H10W76/13; H10W76/132; H10W72/00; H10W72/071; H10W72/073; H10W72/07331; H10W72/07336; H10W72/30; H10W72/351; H10W72/352; H10W72/851; H10W72/874; H10W72/884; H10W90/00; H10W90/701; H10W90/751; H10W90/753; H10W90/754
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
63 words
A semiconductor device comprising: an enclosure; a thermally conductive substrate; a semiconductor die joined to said substrate within said enclosure by means of a joint of a high lead-content solder between said die and said substrate; and a substantially nonoxidizing gaseous medium within said enclosure, said nonoxidizing gaseous medium containing less than 100 parts of oxygen per million parts of said gaseous medium.
Claim 2
Dependent Claim
63 words
A semiconductor device comprising: an enclosure; a thermally conductive substrate; a semiconductor die joined to said substrate within said enclosure by means of a joint of a high lead-content solder between said die and said substrate; and a substantially nonoxidizing gaseous medium within said enclosure, said nonoxidizing gaseous medium containing less than 100 parts of oxygen per million parts of said gaseous medium.
Claim 3
Dependent Claim
23 words
A device according to claim 1, wherein said nonoxidizing atmosphere contains less than 50 parts of water per million parts of said atmosphere
Claim 4
Dependent Claim
23 words
A device according to claim 1, wherein said high lead-content solder consists essentially of at least 90 percent lead, by weight, balance tin.
Claim 5
Dependent Claim
20 words
A device according to claim 1, wherein said substrate includes a high thermal conductivity pedestal next adjacent said solder joint.
Claim 6
Dependent Claim
12 words
A device according to claim 4, wherein said pedestal consists of copper.
Claim 7
Dependent Claim
41 words
A device according to claim 1, further comprising: at least one contact pad on a surface of said semiconductor die, said contact pad comprising said high lead-content solder; and terminal means interconnecting said contact pad to points external to said enclosure.
Claim 8
Dependent Claim
78 words
A transistor comprising: a thermally conductive substrate having a high thermal conductivity pedestal extending from a surface thereof; a transistor die joined to said pedestal by means of a joint of a high lead-content solder between said die and said pedestal; an enclosure surrounding said die and sealed to said substrate at said surface; and a substantially nonoxidizing atmosphere of nitrogen within said enclosure and containing less than 100 parts of oxygen per million parts of said atmosphere.
Claim 9
Dependent Claim
78 words
A transistor comprising: a thermally conductive substrate having a high thermal conductivity pedestal extending from a surface thereof; a transistor die joined to said pedestal by means of a joint of a high lead-content solder between said die and said pedestal; an enclosure surrounding said die and sealed to said substrate at said surface; and a substantially nonoxidizing atmosphere of nitrogen within said enclosure and containing less than 100 parts of oxygen per million parts of said atmosphere.
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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) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |