Patent US3789274A successfully refreshed from Google Patents.
US3789274A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid electrolytic capacitors having hard solder cathode coating
Assignee: Sprague Electric Co
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Filing: 1972-07-24
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Granted: 1974-01-29
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Expires: 1992-07-24
Abstract
Abstract A solid electrolytic capacitor has an electrically conductive counterelectrode system that can advantageously be contacted without the use of flux, and can subsequently be used for high temperature applications, without any accompanying deterioration or corrosion difficulties. The counterelectrode system employs a sprayed layer of a high melting tin-lead alloy in contact with a coating of carbon on the solid electrolyte. The tin-lead carbon contacting layer can advantageously have a lead content of 95 percent by weight, thereby insuring a relatively high melting point therefor.
Inventors
- 👤 W Pfister
- 👤 G Shirn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:26
CPC Classifications
H; H01; H01G; H01G9/00; H01G9/004; H01G9/04; H01G9/042; H01G9/0425
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
30 words
The capacitor of claim 1 wherein said metal anode is at least one film-forming metal selected from the group consisting essentially of tantalum, aluminum, hafnium, titanium, niobium, tungsten and zirconium.
Claim 2
Dependent Claim
24 words
The capacitor of claim 2 wherein said metal anode is tantalum, said dielectric oxide is tantalum pentoxide; and, said semiconductive material is manganese dioxide.
Claim 3
Dependent Claim
19 words
The capacitor of claim 1 wherein said tin-lead alloy is composed of 5 percent tin and 95 percent lead.
Claim 4
Dependent Claim
39 words
The capacitor of claim 4 wherein said anode and said counterelectrode having metal leads extending outward therefrom; and said capacitor is encased in an epoxy resin, said anode lead and said counterelectrode lead extending out from said epoxy resin.
Claim 5
Dependent Claim
32 words
The capacitor of claim 4 wherein said counterelectrode includes an additional porous layer of solder overlying sad tin-lead alloy layer, and a further layer of fluxless solder overlying said porous solder layer.
Claim 6
Dependent Claim
15 words
The capacitor of claim 5 wherein said manganese dioxide layer has a rough outer surface.
Claim 7
Dependent Claim
15 words
The capacitor of claim 6 wherein said manganese dioxide layer has a rough outer surface.
Claim 8
Dependent Claim
109 words
A solid electrolytic capacitor comprising a tantalum anode having a metal lead extending outward therefrom; a layer of tantalum pentoxide on said tantalum anode; a layer of manganese dioxide over said tantalum pentoxide layer, said manganese dioxide layer having a rough outer surface; an electrically conductive counterelectrode comprising a layer of carbon particles over said manganese dioxide layer, and a layer of 5 percent tin-95 percent lead over and in direct contact with said carbon particles, said counterelectrode having a metal lead attached thereto and extending out therefrom; and an epoxy resin covering over said capacitor, said anode lead and said counterelectrode lead extending out from said epoxy resin.
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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) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |