Patent US5831336A successfully refreshed from Google Patents.
US5831336A
Expired / Lapsed
US
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Ternary solder for the enhancement of C-4 fatigue life
Assignee: International Business Machines Corp
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Filing: 1996-07-25
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Granted: 1998-11-03
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Expires: 2016-07-25
Abstract
Abstract An enhanced fatigue life solder comprising, by weight, about 1-3% tin, about 1-3% silver and the balance essentially lead is provided. The solder is particularly useful for joining electronic components and in particular for making C-4 interconnections. A method for using the solder to make electronic components and electric components made using the method are also provided.
Inventors
- 👤 Giulio DiGiacomo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:57
CPC Classifications
H; H10; H10W; H10W72/00; B; B23; B23K; B23K35/00; B23K35/22; B23K35/24; B23K35/26; B23K35/268; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236; H10W72/20; H10W72/251; H10W72/252
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
33 words
An enhanced fatigue resistant solder useful for joining electronic components comprising, by weight, about 1-3% tin, about 1-3% silver and balance lead, wherein the solder contains Ag 3 Sn distributed throughout the solder.
Claim 2
Dependent Claim
33 words
An enhanced fatigue resistant solder useful for joining electronic components comprising, by weight, about 1-3% tin, about 1-3% silver and balance lead, wherein the solder contains Ag 3 Sn distributed throughout the solder.
Claim 3
Dependent Claim
17 words
The solder of claim 1 wherein the tin is about 1-2% and the silver is about 1-2%.
Claim 4
Dependent Claim
17 words
The solder of claim 2 wherein the tin is about 1.25%-1.75% and the silver is about 1.25%-1.75%.
Claim 5
Dependent Claim
17 words
The solder of claim 3 wherein the tin is about 1.4%-1.6% and the silver is about 1.4%-1.6%.
Claim 6
Dependent Claim
62 words
An enhanced fatigue resistant solder useful for joining electronic components comprising, by weight, about 1-3% tin, about 1-3% silver and balance lead wherein the solder is formed by melting the components together to form a molten mixture and cooling the mixture to form a solid solder having a homogenous structure containing finely divided Ag 3 Sn precipitates distributed in the solder structure.
Claim 7
Dependent Claim
62 words
An enhanced fatigue resistant solder useful for joining electronic components comprising, by weight, about 1-3% tin, about 1-3% silver and balance lead wherein the solder is formed by melting the components together to form a molten mixture and cooling the mixture to form a solid solder having a homogenous structure containing finely divided Ag 3 Sn precipitates distributed in the solder structure.
Claim 8
Dependent Claim
17 words
The solder of claim 5 wherein the Ag 3 Sn precipitates are in the form of platelets.
Claim 9
Dependent Claim
20 words
The solder of claim 5 wherein the silver in the solder is totally reacted forming the Ag 3 Sn precipitates.
Claim 10
Dependent Claim
72 words
The solder of claim 5 wherein the silver, tin and lead are melted together and the solder applied by evaporation to a substrate through a mask forming a stratified layer on the substrate comprising a lead layer, an intermediate tin layer and an overlying silver layer, which layers, when the solder is reflowed at an elevated temperature, forms a ternary alloy with a homogenous structure containing finely divided Ag 3 Sn precipitates.
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) | 2001-11-02 | 2002-05-04 | 2002-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-02 | 2006-05-04 | 2006-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-02 | 2010-05-04 | 2010-11-03 | $7700.00 | Window Closed / Lapsed |