Patent US4023725A successfully refreshed from Google Patents.
US4023725A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor device manufacture
Assignee: US Philips Corp
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Filing: 1975-03-03
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Granted: 1977-05-17
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Expires: 1995-03-03
Abstract
Abstract A method of bonding a semiconductor body to a supporting member where the whole back face of the semiconductor body is covered with a thin evaporated layer of chromium or titanium, which layer is then covered with a thin evaporated layer of rhodium, platinum or palladium, which is in turn bonded by a film of solder to the supporting member.
Inventors
- 👤 Peter Robert Ivett
- 👤 Christopher Tooth
- 👤 Leslie Charles Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:12
CPC Classifications
H; H10; H10P; H10P95/00; H10W; H10W72/00; H10W72/071; H10W72/073; H10W72/07331; H10W72/07336; H10W72/075; H10W72/07531; H10W72/07532; H10W72/07533; H10W72/30; H10W72/351; H10W72/352; H10W72/90; H10W72/951; H10W72/952; H10W90/00; H10W90/701; H10W90/731; H10W90/736
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
76 words
A method of mechanically, electrically and thermally bonding the back face of a semiconductor body to a supporting member, comprising the steps of: evaporating a thin layer of chromium onto the back surface of the semiconductor body; evaporating onto the chromium layer a thin layer of metal selected from the group consisting of rhodium, platinum, palladium and alloys thereof; fusing the metallized back surface of the semiconductor body to the supporting member with a solder film.
Claim 2
Independent Claim
76 words
A method of mechanically, electrically and thermally bonding the back face of a semiconductor body to a supporting member, comprising the steps of: evaporating a thin layer of chromium onto the back surface of the semiconductor body; evaporating onto the chromium layer a thin layer of metal selected from the group consisting of rhodium, platinum, palladium and alloys thereof; fusing the metallized back surface of the semiconductor body to the supporting member with a solder film.
Claim 3
Independent Claim
64 words
A method of mechanically, electrically and thermally bonding the back face of a semiconductor body to a supporting member, comprising the steps of: evaporating a thin layer of chromium onto the back surface of the semiconductor body; evaporating onto the chromium layer a thin layer of rhodium; fusing the metallized back surface of the semiconductor body to the supporting member with a solder film.
Claim 4
Independent Claim
64 words
A method of mechanically, electrically and thermally bonding the back face of a semiconductor body to a supporting member, comprising the steps of: evaporating a thin layer of chromium onto the back surface of the semiconductor body; evaporating onto the chromium layer a thin layer of rhodium; fusing the metallized back surface of the semiconductor body to the supporting member with a solder film.
Claim 5
Dependent Claim
19 words
A method as defined in claim 2 wherein the rhodium layer is less than half a micron in thickness.
Claim 6
Dependent Claim
21 words
A method as defined in claim 3 wherein the rhodium layer is less than a tenth of a micron in thickness.
Claim 7
Dependent Claim
19 words
A method as defined in claim 3 wherein the chromium layer is less than half a micron in thickness.
Claim 8
Dependent Claim
29 words
A method as defined in claim 2 wherein the solder material of the solder film is one of the soft solder materials having a melting point below 330° C.
Claim 9
Dependent Claim
23 words
A method as defined in claim 6 wherein the solder material consists essentially of lead, silver and tin, lead being the main constituent.
Claim 10
Dependent Claim
22 words
A method as defined in claim 2 wherein the metallized back surface is fused to the supporting member by capillary flow soldering.
Claim 11
Dependent Claim
25 words
A method as defined in claim 2 wherein the metallized back surface is fused to the supporting member by pressure-bonding via an intermediate solder film.
Claim 12
Dependent Claim
15 words
A method as defined in claim 2 wherein the supporting member comprises a ceramic substrate.
References Cited (Backward Citations)
US3339267A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |