US4398975A
Expired / Lapsed
US
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Conductive paste
Assignee: Sony Corp
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Filing: 1981-12-16
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Granted: 1983-08-16
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Expires: 2001-12-16
Abstract
Abstract A novel conductive paste and a method of making the same in which metallic gallium is combined with a metal or alloy which forms a eutectic with gallium in an amount in excess of its limit of solubility in gallium at a specific temperature. This melt is then treated with a metal powder of a second metal or alloy which alloys with gallium to produce a higher melting alloy, the second metal powder being coated on its surface with the eutectic-forming metal.
Inventors
- 👤 Kenji Ohsawa
- 👤 Takao Ito
- 👤 Koichiro Tanno
- 👤 Masayuki Ohsawa
- 👤 Keiji Kurata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 00:55
CPC Classifications
C; C22; C22C; C22C28/00; H; H01; H01B; H01B1/00; H01B1/02; H01R; H01R4/00; H01R4/58; H05; H05K; H05K1/00; H05K1/02; H05K1/09; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3465; H05K3/3485; H05K3/40; H05K3/4038; H05K2201/00; H05K2201/02; H05K2201/0203; H05K2201/0206; H05K2201/0215; H05K2201/03; H05K2201/0302; H05K2201/0305; H05K2201/09; H05K2201/09818; H05K2201/09845; H05K3/346; H05K3/46; H05K3/4644
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
65 words
A conductive paste comprising: a continuous phase of metallic gallium in combination with a first metal which forms a eutectic with gallium, said metal being present in excess of its solubility limit in gallium at a predetermined temperature, in combination with a second metal powder capable of alloying with gallium, said powder being pre-coated with said first metal and being dispersed through said continuous phase.
Claim 2
Dependent Claim
65 words
A conductive paste comprising: a continuous phase of metallic gallium in combination with a first metal which forms a eutectic with gallium, said metal being present in excess of its solubility limit in gallium at a predetermined temperature, in combination with a second metal powder capable of alloying with gallium, said powder being pre-coated with said first metal and being dispersed through said continuous phase.
Claim 3
Dependent Claim
22 words
A conductive paste according to claim 1 in which: said first metal includes indium, tin, zinc, or bismuth, or an alloy thereof.
Claim 4
Dependent Claim
23 words
A conductive paste according to claim 1 in which said second metal is copper, nickel, cobalt, gold, or an alloy of such metal.
Claim 5
Dependent Claim
14 words
A conductive paste according to claim 2 which contains about 10% by weight tin.
Claim 6
Dependent Claim
14 words
A conductive paste according to claim 2 which contains about 6% by weight zinc.
Claim 7
Dependent Claim
14 words
A conductive paste according to claim 2 which contains about 20% by weight indium.
Claim 8
Dependent Claim
21 words
A conductive paste according to claim 1 in which: said metal powder has a size of from 0.5 to 500 microns.
Claim 9
Dependent Claim
21 words
A conductive paste according to claim 1 in which: said metal powder has a size of about l0 to l00 microns.
Claim 10
Independent Claim
101 words
A method for making a conductive composition which comprises: providing a molten mixture of gallium and a first metal which forms a eutectic with gallium at a temperature in excess of the melting point of said metal, cooling the resulting melt to a lower temperature, adding to the cooled melt a powder having a central core of a second metal or alloy capable of alloying with gallium to form a gallium alloy of a higher melting point than the gallium itself, said core being pre-coated with said first metal, and agitating the resulting mixture to disperse said powder within said melt.
Claim 11
Independent Claim
101 words
A method for making a conductive composition which comprises: providing a molten mixture of gallium and a first metal which forms a eutectic with gallium at a temperature in excess of the melting point of said metal, cooling the resulting melt to a lower temperature, adding to the cooled melt a powder having a central core of a second metal or alloy capable of alloying with gallium to form a gallium alloy of a higher melting point than the gallium itself, said core being pre-coated with said first metal, and agitating the resulting mixture to disperse said powder within said melt.
Claim 12
Dependent Claim
17 words
A method according to claim 9 in which said first metal includes indium, tin, zinc or bismuth.
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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) | 1986-08-15 | 1987-02-14 | 1987-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-15 | 1991-02-14 | 1991-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-15 | 1995-02-14 | 1995-08-16 | $7700.00 | Window Closed / Lapsed |