US4919729A
Expired / Lapsed
US
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Solder paste for use in a reducing atmosphere
Assignee: International Business Machines Corp
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Filing: 1989-05-02
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Granted: 1990-04-24
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Expires: 2009-05-02
Abstract
Abstract A solder paste for use in a reducing atmosphere is disclosed. The solder paste includes a solder powder and an alcohol binder. The reducing atmosphere serves as a flux, thereby eliminating flux residues and the problems associated therewith. Solder splattering is reduced by using a polyhydric alcoholic binder which vaporizes or decomposes before the solder liquifies during heating. The use of such a solder paste in a reducing atmosphere results in no hazardous chemical by-products and, because the solder is handled in the form of a paste, is compatible with electrical components requiring precise dimensional tolerances.
Inventors
- 👤 Peter J. Elmgren
- 👤 Alan J. Emerick
- 👤 Dennis L. Rivenburg, Sr.
- 👤 Mukund K. Saraiya
- 👤 David W. Sissenstein, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:05
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/22; B23K35/36; B23K35/3612; B23K35/24; B23K35/26
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
66 words
A fluxless solder paste heated in a reducing atmosphere for use in a soldering process comprising: a solder powder; a binder comprising at least one alcohol, and said binder having a boiling temperature within the pasty region of a phase diagram of said solder powder, said boiling temperature being determined by said alcohol, said boiling temperature of said binder reducing splattering associated with said soldering process.
Claim 2
Dependent Claim
66 words
A fluxless solder paste heated in a reducing atmosphere for use in a soldering process comprising: a solder powder; a binder comprising at least one alcohol, and said binder having a boiling temperature within the pasty region of a phase diagram of said solder powder, said boiling temperature being determined by said alcohol, said boiling temperature of said binder reducing splattering associated with said soldering process.
Claim 3
Dependent Claim
18 words
The solder powder of claim 1 wherein said solder powder is a mixture of at least two metals.
Claim 4
Dependent Claim
33 words
The solder paste of claim 1 wherein said solder powder is a mixture of at least two metals selected from the group consisting of tin, bismuth, cadmium, antimony, indium, lead, silver, and gold.
Claim 5
Dependent Claim
16 words
The solder paste of claim 1 wherein said alcohol contains no more than 20 carbon atoms.
Claim 6
Dependent Claim
16 words
The solder paste of claim 1 wherein said alcohol contains approximately 1 to 3 hydroxyl groups.
Claim 7
Dependent Claim
34 words
The solder paste of claim 1 wherein said binder is an alcohol selected from the group comprising 1,2 propanediol, 1,3 propanediol, 1,2,3 propanetriol, 1,3 butanediol, 1,4 butanediol, 1,5 pentanediol, 1,6 hexanediol, and 1,5 hexanediol.
Claim 8
Independent Claim
74 words
A method of making a fluxless solder paste for use in a soldering process comprising the steps of: selecting a solder powder which when reflowed will result in a solder bond with the desired electrical and mechanical characteristics, selecting a binder, comprising at least one alcohol, with a boiling point in the pasty region of the solder powder, phase diagram and mixing said solder powder and said binder to form the fluxless solder paste.
Claim 9
Independent Claim
74 words
A method of making a fluxless solder paste for use in a soldering process comprising the steps of: selecting a solder powder which when reflowed will result in a solder bond with the desired electrical and mechanical characteristics, selecting a binder, comprising at least one alcohol, with a boiling point in the pasty region of the solder powder, phase diagram and mixing said solder powder and said binder to form the fluxless solder paste.
Claim 10
Dependent Claim
16 words
The solder paste of claim 1 wherein said alcohol raises said boiling temperature of said binder.
Claim 11
Dependent Claim
16 words
The solder paste of claim 1 wherein said alcohol lowers said boiling temperature of said binder.
Claim 12
Dependent Claim
91 words
A fluxless solder paste heated in a reducing atmosphere for use in a soldering process comprising: a solder powder, a binder comprising at least one alcohol, said binder having a boiling temperature lower than the pasty region of a phase diagram of said solder powder and within 10 percent of the lower bound of said pasty region when said solder powder contains at least 85 percent by weight lead, said boiling temperature being determined by said alcohol, and said boiling temperature of said binder reducing splattering associated with said soldering process.
Claim 13
Dependent Claim
91 words
A fluxless solder paste heated in a reducing atmosphere for use in a soldering process comprising: a solder powder, a binder comprising at least one alcohol, said binder having a boiling temperature lower than the pasty region of a phase diagram of said solder powder and within 10 percent of the lower bound of said pasty region when said solder powder contains at least 85 percent by weight lead, said boiling temperature being determined by said alcohol, and said boiling temperature of said binder reducing splattering associated with said soldering process.
Claim 14
Dependent Claim
18 words
The solder powder of claim 10 wherein said solder powder is a mixture of at least two metals.
Claim 15
Dependent Claim
33 words
The solder paste of claim 10 wherein said solder powder is a mixture of at least two metals selected from the group consisting of tin, bismuth, cadmium, antimony, indium, lead, silver, and gold.
Claim 16
Dependent Claim
16 words
The solder paste of claim 10 wherein said alcohol contains no more than 20 carbon atoms.
Claim 17
Dependent Claim
16 words
The solder paste of claim 10 wherein said alcohol contains approximately 1 to 3 hydroxyl groups.
Claim 18
Dependent Claim
35 words
The solder paste of claim 10 wherein said binder is an alcohol selected from the group comprising 1, 2 propanediol, 1,3 propanediol, 1,2,3 propanetriol, 1,3 butanediol, 1,4 butanediol, 1,5 pentanediol, 1,6 hexanediol, and 1,5 hexanediol.
Claim 19
Dependent Claim
16 words
The solder paste of claim 10 wherein said alcohol raises said boiling temperature of said binder.
Claim 20
Dependent Claim
16 words
The solder paste of claim 10 wherein said alcohol lowers said boiling temperature of said binder.
Claim 21
Independent Claim
97 words
A method of making a fluxless solder paste for use in a reducing atmosphere comprising the steps of: selecting a solder powder which when reflowed will result in a solder band with the desired electrical and mechanical characteristics, selecting a binder comprising at least one alcohol, with a boiling point lower than the pasty region of the solder powder and within 10 percent of the lower bound of said pasty region when said solder powder contains at least 85 percent by weight lead, and mixing said solder powder and said binder to form the fluxless solder paste.
Claim 22
Independent Claim
97 words
A method of making a fluxless solder paste for use in a reducing atmosphere comprising the steps of: selecting a solder powder which when reflowed will result in a solder band with the desired electrical and mechanical characteristics, selecting a binder comprising at least one alcohol, with a boiling point lower than the pasty region of the solder powder and within 10 percent of the lower bound of said pasty region when said solder powder contains at least 85 percent by weight lead, and mixing said solder powder and said binder to form the fluxless solder paste.
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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) | 1993-04-23 | 1993-10-23 | 1994-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-23 | 1997-10-23 | 1998-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-23 | 2001-10-23 | 2002-04-24 | $7700.00 | Window Closed / Lapsed |