US3818581A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitor electrode
Assignee: Saint Gobain Abrasives Inc
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Filing: 1972-09-28
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Granted: 1974-06-25
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Expires: 1992-09-28
Abstract
Abstract Improved capacitor anodes, and like products, in which the product is produced by sintering a powder compact, working the compact down to a smaller shape through the application of compressive forces and in such fashion that the individual powder particles are stretched into fibers to form a resultant electrode product of interconnected elongated fibers with elongated metallurgical bonds corresponding to the original powder-topowder bonds. The improvement comprises forming a very dense core or backing layer in the elongated end product. The core facilitates an attachment of lead wires and avoidance of impurities in the product. It is formed by providing a dense core in the original powder compact either through a graded density of powder therein or insertion of a solid core member, in preferred and distinctly advantageous embodiments. The manufacture of such devices is carried out in a manner to produce solid electrolytic capacitors with good life test stability. Specific densification and bonding conditions, using a sinter-press-sinter three stage process, and extrusion working and electrochemical leaching of a working matrix afford further improvement in performance.
Inventors
- 👤 H Vartanian
- 👤 A Postlethwaite
- 👤 R Mao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:47
CPC Classifications
H; H01; H01G; H01G9/00; H01G9/004; H01G9/04; H01G9/048; H01G9/052; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49169; Y10T29/49801
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
98 words
Process in accordance with claim 1 comprising, assembling powders of a valve metal around a rod of a valve metal, consolidating the powder into a coherent porous mass bonded to the core rod, impregnating the porous outer layer thus formed with a second material capable of co-working therewith, mechanically working the composite to an elongated form by the application of compressive forces to fiber the powder and reduce the rod to a central wire and then removing said infiltrant to produce pore structure in the fiber layer, and further comprising, bonding a lead conductor to said central wire.
Claim 2
Dependent Claim
67 words
Process in accordance with claim 1 wherein powders of a valve metal are formed as a continuous layer along the face surface of a sheet of a valve metal, consolidating the powders into a coherent porous mass bonded to said valve metal, infiltrating the porous powder layer with a second material capable of co-working therewith prior to said co-working and wherein a continuous fiber layer is produced.
Claim 3
Dependent Claim
58 words
The process of claim 1 wherein the porous powder layer as a density of at least 35 percent of theoretical density and no greater than 50 percent of the theoretical density of the valve metal, and wherein the removal of impregnant is carried out by electrochemical leaching using the product as an electrode in the electrochemical leaching process.
Claim 4
Dependent Claim
48 words
The process of claim 8 wherein the consolidation is carried out by sintering the multi-layered initial composite in a mold and subsequently further consolidating it to the required density range by a process which comprises a pressing step to form a dense outer skin on the powder layer.
Claim 5
Dependent Claim
23 words
The process of claim 3 wherein a lead wire is attached by a face-to-face weld thereof with said solid layer of the composite.
Claim 6
Dependent Claim
40 words
The process of claim 2 wherein the said lead has a narrow cross-section dimension of the same ordEr of magnitude as a narrow cross-section dimension of the solid layer of the composite and wherein the two are butt-welded on edge.
Claim 7
Dependent Claim
45 words
The process of claim 7 wherein the weld is carried out prior to removal of said impregnant and wherein the surface of said solid layer is pre-treated to remove the said impregnant material from the vicinity of the weld site prior to conducting the weld.
Claim 8
Dependent Claim
32 words
The process of claim 1 wherein the solid layer used comprises a circular cross-section member, such as a rod or the like, and the porous compact is formed around said solid layer.
Claim 9
Dependent Claim
17 words
The process of claim 6 wherein the solid and porous layers are formed as face-to-face flat sheets.
Claim 10
Dependent Claim
20 words
The process of claim 10 wherein the sheet formed composite is cut into chips before removal of the impregnant materials.
Claim 11
Dependent Claim
21 words
The process of claim 10 wherein the sheet form composite material is cut into chips after removal of the impregnant material.
Claim 12
Dependent Claim
209 words
Process for producing a capacitor electrode or the like comprising the steps of forming contacting layers of a porous skeletal compact and a solid metal layer and co-working the composite material to fiber the porous skeletal compact portion while bonding the two layers, said first porous layer then comprising elongated, valve metal fibers, the layer being elongated as a whole and the individual fibers thereof being also axially oriented in the direction of elongation of the layer, the fibers being interconnected by metallurgical bonds, the bonds being elongated parallel to the fiber elongation direction, with a major portion of the bond length being greater than average fiber diameter, with said second layer in reduced cross section thickness, and wherein the solid layer used comprises a circular cross-section member, such as a rod or the like, and the porous compact is formed around said solid layer, infiltrating the porous layer with a metal before co-working and removing the infiltrant after co-working, the infiltrant both forming said rod and filling the pores of said porous layer and wherein the solid layer (core) and infiltrant are removed by electrochemical leaching, and lead attachment is made by implanting a valve metal lead wire in the resulting anode cavity and heat treating to bond.
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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) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |