US3879273A - Process for the manufacture of aluminium electrodes for electrolytic capacitors - Google Patents
Process for the manufacture of aluminium electrodes for electrolytic capacitors Download PDFInfo
- Publication number
- US3879273A US3879273A US413447A US41344773A US3879273A US 3879273 A US3879273 A US 3879273A US 413447 A US413447 A US 413447A US 41344773 A US41344773 A US 41344773A US 3879273 A US3879273 A US 3879273A
- Authority
- US
- United States
- Prior art keywords
- strip
- manufacture
- electrolytic capacitors
- aluminium
- etched
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
- H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
- H01G9/004—Details
- H01G9/04—Electrodes or formation of dielectric layers thereon
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/4998—Combined manufacture including applying or shaping of fluent material
- Y10T29/49988—Metal casting
- Y10T29/49991—Combined with rolling
Definitions
- the electrodes of an electrolytic capacitor generally consist of a roughened i.e. etched aluminium strip. By roughening the strip an increase in surface area and thereby an increase in capacity is achieved, or for a prescribed capacity a reduction in the dimension of the electrode is achieved.
- Pure aluminium is normally used as starting material for producing etched anode strips and for the production of etched cathode strip pure aluminium or manganese-containing aluminium alloys are used. These materials are cast as ingots with rectangular cross section by the usual continuous casting and permanent mould casting processes. The ingots are usually heated to a rolling temperature between 400C and 500C and rolled down to a plate thickness of 2-10 mm on a hot rolling mill. The plates are cold rolled in several reduction passes down to strip thickness and etched either in this condition or after an additional heat treatment.
- aluminium strip to be etched is cast directly from the molten state as a strip and then rolled to its final thickness.
- Example 1 (Al 99) Capacity in uF/cm?
- a continuous casting of strip has been practised.
- a material is cast directly from the melt in the form of a strip l-40 mm thick and then hot rolled and cold rolled or directly cold rolled to its final thickness.
- a process for the manufacture of aluminum electrodes, for use in electrolytic capacitors comprising the steps of continuously casting an aluminum strip having a thickness of between about 1 mm and about 40 rolling said aluminum strip to its final thickness;
Abstract
A process for the manufacture of etched aluminium electrodes for electrolytic capacitors wherein the strips to be etched are cast directly as a strip from the molten state and then rolled to the final thickness before electrolytically etching them in the presence of chloride ions.
Description
United States Patent Miihlh'ausser et al.
PROCESS FOR THE MANUFACTURE OF ALUMINIUM ELECTRODES FOR ELECTROLYTIC CAPACITORS Inventors: Martin Miihlhausser, Singen.
Hohentw; Christian Roth. Gottmadingen. both of Germany Assignee: Aluminium-Walzwerke Singen GmbI-I, Singen/Hohentw. Germany Filed: Nov. 7, 1973 Appl. No.: 413.447
Foreign Application Priority Data Nov. 11. 1972 Germany 2255309 US. Cl. 204/l 29.75; 29/527.7; 29/570;
29/DIG. 10 Int. Cl C01b 13/04 Field of Search 29/527.7, 570, 592. DIG. 16; 164/82; 204/l29.75
[ Apr. 22, 1975 [56] References Cited UNITED STATES PATENTS 1.935.860 11/1933 Robinson 29/570 2.106.178 1/1938 Keller ct 211.. 29/570 X 2.206.050 7/1940 Robinson 29/570 3.316.164 4/1967 Welch 204/l29.75 X 3.351.442 11/1967 Hooper 204/l29.75 X
Primary Eraminer-Milton S. Mehr Assistant Examiner-D. C. Rciley, 111 Attorney. Agent, or Firm-Ernest F. Marmorek 1 Claim, No Drawings PROCESS FOR THE MANUFACTURE OF ALUMINIUM ELECTRODES FOR ELECTROLYTIC CAPACITORS The electrodes of an electrolytic capacitor generally consist of a roughened i.e. etched aluminium strip. By roughening the strip an increase in surface area and thereby an increase in capacity is achieved, or for a prescribed capacity a reduction in the dimension of the electrode is achieved.
Pure aluminium is normally used as starting material for producing etched anode strips and for the production of etched cathode strip pure aluminium or manganese-containing aluminium alloys are used. These materials are cast as ingots with rectangular cross section by the usual continuous casting and permanent mould casting processes. The ingots are usually heated to a rolling temperature between 400C and 500C and rolled down to a plate thickness of 2-10 mm on a hot rolling mill. The plates are cold rolled in several reduction passes down to strip thickness and etched either in this condition or after an additional heat treatment.
The etched strips produced in this way do not, in many cases fulfill todays requirements for a satisfactory surface area increase necessary in the construction of an electrolytic capacitor of the smallest possible volume. It was of value therefore to find a process by which it is possible to obtain still greater increases in the surface area than by the known processes.
surface area. It is characterised in that the aluminium strip to be etched is cast directly from the molten state as a strip and then rolled to its final thickness.
Presumably the better etching behaviour of the material produced by strip-casting results from the significantly higher rate of solidification during casting.
EXAMPLES An ingot of 99% pure aluminium and an ingot of AlMn alloy, both continuously cast, were annealed at 500C for 2 hours, hot rolled to a plate thickness of 6 mm and then without heat treatment cold rolled to a strip 0.05 mm thick. For comparision a strip from a melt of 99% pure aluminium and a strip from an AlMn melt were cast directly as 7 mm thick strips in a stripcasting plant and then rolled down to the same final thickness as the other two strips without an intermediate heat treatment. All strips were degreased and then etched in an aqueous solution of 20% NaCl at 90C using a current density of 100 A/dm and consuming 3000 C/dm".
The determination of the capacity was carried out in accordance with the DIN 41330 specification at 0 and 10 volts in a saturated ammonium pentaborate solution having a bath resistance of 60 to 70 ohm.cm at room temperature. In addition to this the characteristic data for the mechanical properties of the strips were determined before etching. The results are summarized in the following tables.
Example 1 (Al 99) Capacity in uF/cm? For some years in addition to the above mentioned casting of ingots, a continuous casting of strip has been practised. By this latter technique a material is cast directly from the melt in the form of a strip l-40 mm thick and then hot rolled and cold rolled or directly cold rolled to its final thickness.
It was found on comparison of the aluminium strip ;made from cast strips with those made from cast ingots 'that the former showed a significantly greater increase in the surface area after the same etching treatment.
The results show that the mechanical strength after solidifying is independent of the method of casting. The result of etching and the capacity measurement on the other hand show clearly an increase in capacity in the case of the metal strip produced by the strip-casting process.
What is claimed is:
1. A process for the manufacture of aluminum electrodes, for use in electrolytic capacitors, comprising the steps of continuously casting an aluminum strip having a thickness of between about 1 mm and about 40 rolling said aluminum strip to its final thickness; and
etching said rolled strip electrolytically in a chloride containing electrolyte.
Claims (1)
1.A PROCESS FOR THE MANUFACTURE OF ALUMINUM ELECTRODES, FOR USE IN ELECTROLYTIC CAPACITORS, COMPRISING THE STEPS OF CONTINUOUSLY CASTING AN ALUMINUM STRIP HAVING A THICKNESS OF BETWEEN ABOUT 1 MM AND ABOUT 40 MM; ROLLING SAID ALUMINUM STRIP TO ITS FINAL THICKNESS; ND ETCHING SAID ROLLED STRIP ELECTROLYTICALLY IN A CHLORIDE CONTAINING ELECTROLYTE.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19722255309 DE2255309B2 (en) | 1972-11-11 | 1972-11-11 | PROCESS FOR THE PRODUCTION OF ALUMINUM ELECTRODES FOR ELECTROLYTE CAPACITORS |
Publications (1)
Publication Number | Publication Date |
---|---|
US3879273A true US3879273A (en) | 1975-04-22 |
Family
ID=5861449
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US413447A Expired - Lifetime US3879273A (en) | 1972-11-11 | 1973-11-07 | Process for the manufacture of aluminium electrodes for electrolytic capacitors |
Country Status (8)
Country | Link |
---|---|
US (1) | US3879273A (en) |
CA (1) | CA997706A (en) |
CH (1) | CH559964A5 (en) |
DE (1) | DE2255309B2 (en) |
FR (1) | FR2206570B1 (en) |
GB (1) | GB1433767A (en) |
IT (1) | IT1001684B (en) |
NL (1) | NL7315242A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0049115A2 (en) * | 1980-09-30 | 1982-04-07 | Showa Aluminum Kabushiki Kaisha | Aluminium alloy foil for cathode of electrolytic capacitors |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1935860A (en) * | 1932-08-02 | 1933-11-21 | Sprague Specialties Co | Electrolytic device |
US2106178A (en) * | 1937-03-23 | 1938-01-25 | Aluminum Co Of America | Electrolytic condenser |
US2206050A (en) * | 1934-03-21 | 1940-07-02 | Sprague Specialties Co | Electrolytic device |
US3316164A (en) * | 1964-04-23 | 1967-04-25 | Sprague Electric Co | Etching of aluminum foil |
US3351442A (en) * | 1966-10-21 | 1967-11-07 | Republic Foil Inc | Treatment of aluminum foil and product produced thereby |
-
1972
- 1972-11-11 DE DE19722255309 patent/DE2255309B2/en not_active Ceased
-
1973
- 1973-10-31 CH CH1531173A patent/CH559964A5/xx not_active IP Right Cessation
- 1973-11-07 NL NL7315242A patent/NL7315242A/xx not_active Application Discontinuation
- 1973-11-07 US US413447A patent/US3879273A/en not_active Expired - Lifetime
- 1973-11-09 FR FR7339938A patent/FR2206570B1/fr not_active Expired
- 1973-11-09 CA CA185,439A patent/CA997706A/en not_active Expired
- 1973-11-09 GB GB5209873A patent/GB1433767A/en not_active Expired
- 1973-11-09 IT IT31145/73A patent/IT1001684B/en active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1935860A (en) * | 1932-08-02 | 1933-11-21 | Sprague Specialties Co | Electrolytic device |
US2206050A (en) * | 1934-03-21 | 1940-07-02 | Sprague Specialties Co | Electrolytic device |
US2106178A (en) * | 1937-03-23 | 1938-01-25 | Aluminum Co Of America | Electrolytic condenser |
US3316164A (en) * | 1964-04-23 | 1967-04-25 | Sprague Electric Co | Etching of aluminum foil |
US3351442A (en) * | 1966-10-21 | 1967-11-07 | Republic Foil Inc | Treatment of aluminum foil and product produced thereby |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0049115A2 (en) * | 1980-09-30 | 1982-04-07 | Showa Aluminum Kabushiki Kaisha | Aluminium alloy foil for cathode of electrolytic capacitors |
EP0049115A3 (en) * | 1980-09-30 | 1984-03-28 | Showa Aluminium Corporation | Aluminium alloy foil for cathode of electrolytic capacitors |
Also Published As
Publication number | Publication date |
---|---|
FR2206570B1 (en) | 1980-02-08 |
IT1001684B (en) | 1976-04-30 |
DE2255309A1 (en) | 1974-05-22 |
CA997706A (en) | 1976-09-28 |
GB1433767A (en) | 1976-04-28 |
DE2255309B2 (en) | 1976-08-05 |
FR2206570A1 (en) | 1974-06-07 |
CH559964A5 (en) | 1975-03-14 |
NL7315242A (en) | 1974-05-14 |
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