US4504849A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor devices and a solder for use in such devices
Assignee: USPHILIPS Corp 100 EAST 42ND ST NEW YORK NY A CORP OF
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Filing: 1982-07-14
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Granted: 1985-03-12
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Expires: 2002-07-14
Abstract
Abstract A semiconductor device, for example a power rectifier, formed in a semiconductor body has a contact area coated with a metal layer of, for example, gold. A metallic member is soldered to the layer with an alloy comprising at least 80% lead, the balance being indium and silver in a ratio of at least 4:1 and at most 10:1. One such solder which has good wetting characteristics for improved bond strength contains approximately 92% lead, 7% indium, and 1% silver.
Inventors
- 👤 Neil A. Davies
- 👤 Edward T. E. Hughes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:22
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/20; H10W70/24; H10W72/00; H10W72/30; H10W72/071; H10W72/073; H10W72/07331; H10W72/07336; H10W72/351; H10W72/352
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
61 words
A semiconductor device comprising a semiconductor body having a metallized contact area soldered to a metallic member with a solder which comprises at least 80% lead, the balance of the solder being substantially all indium and silver, characterized in that the indiun content of the solder is at least four and at most ten times as great as the silver content.
Claim 2
Dependent Claim
61 words
A semiconductor device comprising a semiconductor body having a metallized contact area soldered to a metallic member with a solder which comprises at least 80% lead, the balance of the solder being substantially all indium and silver, characterized in that the indiun content of the solder is at least four and at most ten times as great as the silver content.
Claim 3
Dependent Claim
23 words
A semiconductor device as claimed in claim 1, characterized in that the solder comprises at least 5% indium and at most 2% silver.
Claim 4
Dependent Claim
28 words
A semiconductor device as claimed in claim 1 or 2, characterized in that the indium content of the solder is seven times as great as the silver content.
Claim 5
Dependent Claim
22 words
A semiconductor device as claimed in claim 3, characterized in that the solder comprises approximately 92% lead, 7% indium, and 1% silver.
Claim 6
Dependent Claim
30 words
A semiconductor device as claimed in claim 1 or 2, characterized in that the contact area is metallized with a system of different metal layers, the outermost layer being gold.
Claim 7
Dependent Claim
19 words
A semiconductor device as claimed in claim 1 or 2, characterized in that the semiconductor body comprises mainly silicon.
Claim 8
Dependent Claim
41 words
An alloy for use as a solder, comprising at least 80% lead, the balance being substantially all indium and silver, characterized in that the indium content is at least four and at most ten times as great as the silver content.
Claim 9
Dependent Claim
41 words
An alloy for use as a solder, comprising at least 80% lead, the balance being substantially all indium and silver, characterized in that the indium content is at least four and at most ten times as great as the silver content.
Claim 10
Dependent Claim
25 words
An alloy as claimed in claim 7, characterized in that the indium content is at least 5%, and the silver content is at most 2%.
Claim 11
Dependent Claim
24 words
An alloy as claimed in claim 7 or 8, characterized in that the indium content is seven times as great as the silver content.
Claim 12
Dependent Claim
23 words
An alloy as claimed in claim 9, characterized in that the lead, indium and silver contents are approximately 92%, 7% and 1% respectively.
References Cited (Backward Citations)
US3878442A
Cited
US3771211A
Cited
US3820152A
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US3913120A
Cited
US3986255A
Cited
JPS5578536A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-03-11 | 1988-09-10 | 1989-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-03-11 | 1992-09-10 | 1993-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-03-11 | 1996-09-10 | 1997-03-12 | $7700.00 | Window Closed / Lapsed |