Patent US3735211A successfully refreshed from Google Patents.
US3735211A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor package containing a dual epoxy and metal seal between a cover and a substrate, and method for forming said seal
Assignee: Fairchild Semiconductor Corp
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Filing: 1971-06-21
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Granted: 1973-05-22
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Expires: 1991-06-21
Abstract
Abstract A cover is hermetically sealed to a substrate by first joining the cover to the substrate by epoxy and then soldering the exposed edge of the cover to a metal film on the substrate to provide an hermetic seal. The epoxy prevents flux used during the soldering operation from entering the cavity formed between the cover and substrate and there degrading the performance of any semiconductor device placed in the cavity.
Inventors
- 👤 D Kapnias
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:59
CPC Classifications
H; H10; H10W; H10W76/00; H10W76/10; H10W76/12; H10W76/15; H10W76/157; H10W76/153; H10W76/60; H10W72/00; H10W72/851; H10W72/874; H10W72/884; H10W90/00; H10W90/701; H10W90/731; H10W90/734; H10W90/751; H10W90/754
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
51 words
Structure as in claim 1 wherein said substrate comprises: a ceramic material containing a top and a bottom surface; an annular-shaped dielectric formed over selected portions of said top surface; and an annular-shaped metal layer placed on said annular-shaped dielectric, said annular-shaped metal layer being larger than said annular-shaped epoxy preform.
Claim 2
Dependent Claim
26 words
Structure as in claim 2 wherein said annular-shaped dielectric layer comprises a first annular-shaped dielectric layer containing on its exposed surface a second annular-shaped dielectric layer.
Claim 3
Dependent Claim
22 words
Structure as in claim 1 wherein said annular-shaped metal layer comprises an alloy selected from the group consisting of platinum-gold and paladium-silver.
Claim 4
Dependent Claim
12 words
Structure as in claim 4 wherein said solder comprises a lead-tin solder.
Claim 5
Dependent Claim
68 words
Structure as in claim 1 wherein said epoxy preform is on the top surface of said substrate on the same side of said substrate as is said void, and adjacent the edge of said substrate, and said solder is on the bottom surface of said substrate adjacent the edge of said substrate sealing an extension of the edge of said cover to the bottom surface of said substrate.
Claim 6
Dependent Claim
51 words
Structure as in claim 1 wherein said epoxy is on the same side of said substrate as is the void between said cover and said substrate and said solder is on the outer surface of said cover and said substrate on the same side of said substrate as is said void.
Claim 7
Dependent Claim
130 words
Structure as in claim 1 wherein said substrate comprises; a ceramic plate with a metal pattern on one side of said ceramic plate; a first annular-shaped dielectric layer over said metal pattern surrounding the area on said substrate to which semiconductor die are to be bonded; an annular-shaped epoxy preform adherent to said first annular dielectric layer on the inner surface of said first annular-shaped dielectric layer; a second annular-shaped dielectric layer adherent to said first dielectric layer adhacent to said first annular-shaped epoxy preform but outside said annular-shaped epoxy preform; a film of metal adherent to the second annular-shaped dielectric layer; a cover the edge of which is adherent to said annular-shaped epoxy preform; and solder adherent to said film of metal and the outer edge of said cover.
Claim 8
Independent Claim
87 words
The method of forming a semiconductor package which comprises: forming a layer of metallization on a ceramic substrate; forming an annular-shaped dielectric layer on said substrate surrounding the area on which semiconductor die are to be placed on said substrate; forming an annular-shaped film of metal on the outer surface of said annular-shaped dielectric layer; forming an annular-shaped epoxy preform on the inner surface of said first annular-shaped dielectric layer; placing a cover on said annular-shaped epoxy preform; and soldering said cover to said film of metal.
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) | 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 |