US2336846A - Etching of capacitor armatures - Google Patents
Etching of capacitor armatures Download PDFInfo
- Publication number
- US2336846A US2336846A US183131A US18313138A US2336846A US 2336846 A US2336846 A US 2336846A US 183131 A US183131 A US 183131A US 18313138 A US18313138 A US 18313138A US 2336846 A US2336846 A US 2336846A
- Authority
- US
- United States
- Prior art keywords
- foil
- etching
- electrolyte
- etched
- per cent
- 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
Links
- 238000005530 etching Methods 0.000 title description 25
- 239000003990 capacitor Substances 0.000 title description 10
- 239000011888 foil Substances 0.000 description 39
- 239000003792 electrolyte Substances 0.000 description 17
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 14
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 14
- 229910052751 metal Inorganic materials 0.000 description 11
- 239000002184 metal Substances 0.000 description 11
- 229910052782 aluminium Inorganic materials 0.000 description 8
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 8
- 238000000034 method Methods 0.000 description 7
- 238000003486 chemical etching Methods 0.000 description 6
- 239000002253 acid Substances 0.000 description 5
- 239000007864 aqueous solution Substances 0.000 description 5
- 239000003153 chemical reaction reagent Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000000903 blocking effect Effects 0.000 description 3
- 150000001805 chlorine compounds Chemical class 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 230000001502 supplementing effect Effects 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 239000000908 ammonium hydroxide Substances 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- ORTQZVOHEJQUHG-UHFFFAOYSA-L copper(II) chloride Chemical compound Cl[Cu]Cl ORTQZVOHEJQUHG-UHFFFAOYSA-L 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 238000000866 electrolytic etching Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000001117 sulphuric acid Substances 0.000 description 1
- 235000011149 sulphuric acid Nutrition 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-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
- H01G9/048—Electrodes or formation of dielectric layers thereon characterised by their structure
- H01G9/055—Etched foil electrodes
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
- C25F3/00—Electrolytic etching or polishing
- C25F3/02—Etching
- C25F3/04—Etching of light metals
Definitions
- the present invention relates to" the preparation of armatures for electric capacitors.
- composition'of the electrolytic bath and the conditions of electrolysis may be varied and should be governed by the. character of the metal to be etched and other conditionath'e foletching electrolyte from the deep cuts in the a 6 Claims. 00!. 204-141) V v lowing illustrative examples will illustrate my invention.
- the etching electrolyte may consist of an aqueous solution of hydrochloric acid, an acid concentration well suited for etching purposes being about five per cent. agents maybe used as, for example, ammonium hydroxide, hydrofluoric acid, boric acid; sulphuric acid or acetic acid. However, hydrochloric acid is preferred.
- the metal to be etched for example, aluminum foil, is caused to function as anode in such bath, the cathode conveniently consisting of carbon or other suitable inert conductive material. A bath temperature of 50 to C. is suitable.
- a direct current having a density of about one-quarter ampere per square inch of active foil-arca and a voltage of about 4 to 6 volts may be impressed between the foil anode and the cathodein the electrolyte.
- Foil to be etched may be passed through the bath at such rate that a given area functions as anode in I I the electrolytic bath for two or three minutes.
- hydrochloric acid solution When hydrochloric acid solution is used as the etching electrolyte, its activity is increased by the presence of about two to twelve per cent of metallic chlorides as, for example, sodium chloride, aluminum chloride and copper chloride.
- metallic chlorides as, for example, sodium chloride, aluminum chloride and copper chloride.
- the content of aluminum chloride preferably should be maintained as low as about 6 per cent.
- the method of treating aluminum foil preparatory to the formation of a current blocking film thereon which consists in introducing said foil into an etching electrolyte consisting essentially of an aqueous solution of hydrochloric acid of about 5 per cent concentration and about 2 to 6 per cent aluminum chloride, subjecting said foil to the anodic etching efiect of an electric current between said foil and a cooperating electrode in said electrolyte thereby supplementing the chemical etching sheet of said electrolyte, continuing said treatment for a length of time sumcient to cause the resulting etching ofsaid foil to increase the efiective capacity value of the etched surface and thereupon freeing said foil from said electrolyte.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Power Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Microelectronics & Electronic Packaging (AREA)
- ing And Chemical Polishing (AREA)
- Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
Description
Patented Dec. 14, 1943 umrso sp res PATENT orr ctz.
York
, No Drawing. Application January 8, 1938, Serial 280.183.131
The present invention relates to" the preparation of armatures for electric capacitors.
It is knownthat animprovement may be effected in electrolytic capacitors by etching the armature size.
Heretofore, it has been the practice to chemically etch' the surface of capacitor metal by means of exposure to a solution ofacid. When aluminum is subjected to such chemical etching, careful control is required of the various etching conditions, such for example, as acid concentration, temperature of reaction, and accumulation of by-products. When the material etched by such chemical process consists of aluminum foil, it is found that foil obtained from different sources reacts diflerently with a given acid etcing bath. It is difllcult to exercise this required close contra in ordinary factory production. Even when the etching process is carried out under the supervision -of highly skilled attendants, the tests and inspection which are required slows up the rate of production.
When it is'attempted to replace the purely chemical etching procedure by electrolytic etching, the temperature, acidity and other conditions being so chosen that the removal of metal by ordinary chemical solution is substantially prevented, then deep cuts or scoring are produced in the surface of the metal being etched. As the metal armature stock commonly consists of thin foil, such cutting effect spoils or destroys the foil. gurthermore, it is dimcult to completely remove e met I have discovered that unexpectedly advantageous results are produced by 'etching armature metal by a combination of chemical and electrolytic action, the metal foil, or other armature material functioning as anode inan electrolytic bath which is capable also of producing ordinary chemicahetching of metal at a slow rate. This combination effect produces an easily controlled shallow etching and not a deep scoring of themetal. When specifying aluminur'n chloride as an accelerator of acidactivity in 'a. claim for this invention I wish also to cover equivalent chlorides such as the chlorides of sodium and copper.
While the composition'of the electrolytic bath and the conditions of electrolysis may be varied and should be governed by the. character of the metal to be etched and other conditionath'e foletching electrolyte from the deep cuts in the a 6 Claims. 00!. 204-141) V v lowing illustrative examples will illustrate my invention.
The etching electrolyte may consist of an aqueous solution of hydrochloric acid, an acid concentration well suited for etching purposes being about five per cent. agents maybe used as, for example, ammonium hydroxide, hydrofluoric acid, boric acid; sulphuric acid or acetic acid. However, hydrochloric acid is preferred. The metal to be etched, for example, aluminum foil, is caused to function as anode in such bath, the cathode conveniently consisting of carbon or other suitable inert conductive material. A bath temperature of 50 to C. is suitable. A direct current having a density of about one-quarter ampere per square inch of active foil-arca and a voltage of about 4 to 6 volts may be impressed between the foil anode and the cathodein the electrolyte. Foil to be etched may be passed through the bath at such rate that a given area functions as anode in I I the electrolytic bath for two or three minutes.
When hydrochloric acid solution is used as the etching electrolyte, its activity is increased by the presence of about two to twelve per cent of metallic chlorides as, for example, sodium chloride, aluminum chloride and copper chloride. The content of aluminum chloride preferably should be maintained as low as about 6 per cent. when other acids are used for the etching electrolyte low voltage anodic treatment to produce a light oxide film in order to prevent uncontrolled atmospheric oxidation which resultsin erratic capacity and power factor characteristic when the etched and oxidized armatures eventually are fabricated into capacitor units.
As a result of this conjoint electrolytic and nonelectroly'tic etching the rate of production of etched foil is materially increased, the consumption of acid per unit weight of metal acted upon is decreased and the uniformity of capacitors made from such etched armature foil is improved. In addition to such improvements the capacitors Other electrolytic made from, such anodically etched foil possess a more stable capacity during periods of non-use,
or as commonly stated during the shelf life" period. The non-uniformities formerly noted in capacitors containing chemically etched armature foil obtained from different sources largely are eliminamd.
What I claim as new and desire to secure by Letters Patent of the United States is:
l. The method of treating aluminum capacitor foil preparatory to producing a current-blocking film thereon which consists in immersing said foil in an aqueousreagent containing about 5 percent hydrochloric acid and about 2 to 12 per cent or,
aluminum chloride, maintaining said reagent at a temperature of about 50 to 75 0., conducting between said foil functioning as anode and a cooperating cathode of carbon 9. direct current at a potential of about 4 to 6 volts and a density of about one-quarter ampere per square inchof active electrode surface, thereby causing etching by a combined chemical and electrolytic action,
continuing said etching until the capacity value of the etched surface is eflectively increased, and thereupon freeing said foil from said reagent.
2. The method of treating aluminum foil preparatory to producing a current-blocking film ,thereon for use in electrolytic capacitors which consists in introducing said foil into an electrolytic bath comprising an aqueous solution containing about 5 per centof hydrochloric acidwhich is capable of producing chemical etching at a slow rate and approximately two to twelve per cent of aluminum chloride, impressing be tween said foil functioning as anode in said reagent and a cooperating cathode a direct current having at the active anode surface a density of about one-fourth ampere per square inch to increase the rate of etching, continuing such treatment for about two or three minutes for a given area to produce shallow etching without film thereon which consists in introducing said deep scoring of the etched metal surface and continuing said treatment for a length of time sufficient to cause the resulting etching of said foil to increase the efiective capacity value of theetched surface and thereupon freeing said foil from said reagent.
4. The method of treating aluminum foil preparatory to the formation of a current blocking foil into an etching electrolyte; consisting essentially of an aqueous solution of hydrochloric acid of about 5 per cent concentration and about 6 per cent of aluminum chloride, subjecting said foil to the anodic etching efiect of an electric current between said foil and a cooperating electrode in said electrolyte thereby supplementing the chemical etching eflect of said electrolyte,
continuing said treatment for a length of time sufiicient to cause the resulting etching of said foil to increase the efiective capacity value of the etched surface and thereupon freeing said foil from said electrolyte.
5." The method of treating aluminum foil preparatory to the formation of a current blocking film thereon which consists in introducing said foil into an etching electrolyte consisting essentially of an aqueous solution of hydrochloric acid of about 5 per cent concentration and about 2 to 6 per cent aluminum chloride, subjecting said foil to the anodic etching efiect of an electric current between said foil and a cooperating electrode in said electrolyte thereby supplementing the chemical etching sheet of said electrolyte, continuing said treatment for a length of time sumcient to cause the resulting etching ofsaid foil to increase the efiective capacity value of the etched surface and thereupon freeing said foil from said electrolyte. v
6. The method of treating aluminum foil preparatory to the formation of a current blocking film thereon which consists in introducing said foil into an etching. electrolyte consisting essentially of an aqueous solution of hydrochloric acid of about 5 per cent concentration and about 2 to- 12 per cent of aluminum chloride, subjecting said foil to the anodic etching efiect of an electric current between said foil and a cooperating electrode in said electrolyte thereby supplementing the chemical etching effect of said electrolyte,
continuing said treatment for a length of time su fiicient to cause the resulting etching. of said foil to increase the efliective capacity value of the etched surface and thereupon freeing said foil 5 from said electrolyte. 5
FRANK M CLARK.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US183131A US2336846A (en) | 1938-01-03 | 1938-01-03 | Etching of capacitor armatures |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US183131A US2336846A (en) | 1938-01-03 | 1938-01-03 | Etching of capacitor armatures |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2336846A true US2336846A (en) | 1943-12-14 |
Family
ID=22671573
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US183131A Expired - Lifetime US2336846A (en) | 1938-01-03 | 1938-01-03 | Etching of capacitor armatures |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2336846A (en) |
Cited By (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2472304A (en) * | 1944-03-13 | 1949-06-07 | Aluminum Co Of America | Method of etching aluminum |
| US2598043A (en) * | 1947-02-20 | 1952-05-27 | Reynolds Metals Co | Process of preparing planographic printing plates |
| US2796334A (en) * | 1955-02-23 | 1957-06-18 | Aluminum Co Of America | Etching aluminum |
| US2853445A (en) * | 1956-04-06 | 1958-09-23 | Aerovox Corp | Process of etching aluminum foil for electrolytic capacitor |
| US2863811A (en) * | 1955-05-09 | 1958-12-09 | Gen Electric | Method of etching capacitor electrodes |
| US2962364A (en) * | 1958-08-15 | 1960-11-29 | Modern Engraving And Machine C | Process and composition for developing images and designs on metal |
| US2964453A (en) * | 1957-10-28 | 1960-12-13 | Bell Telephone Labor Inc | Etching bath for copper and regeneration thereof |
| US3002899A (en) * | 1959-07-31 | 1961-10-03 | Jr Walter E Reid | Adhesion of nickel to chromium |
| US3072546A (en) * | 1959-03-02 | 1963-01-08 | Lawton Printing Company | Graining printing plates |
| US3075894A (en) * | 1959-01-23 | 1963-01-29 | Westinghouse Electric Corp | Method of electroplating on aluminum surfaces |
| US3108918A (en) * | 1944-01-12 | 1963-10-29 | Harold J Plumley | Trepanning of cased explosives by etching |
| US3284326A (en) * | 1962-04-09 | 1966-11-08 | Sprague Electric Co | Electrolytic etching of anodisable metal foil |
| DE1240360B (en) * | 1962-08-10 | 1967-05-11 | Siemens Ag | Process for improving oxide layers produced by anodic oxidation on aluminum electrodes |
| US3321389A (en) * | 1964-07-20 | 1967-05-23 | Mallory & Co Inc P R | Method of anodically etching aluminum foils at elevated temperatures in an electrolyte including chloride and sulfate ions |
| US3755115A (en) * | 1970-01-02 | 1973-08-28 | Philips Corp | Method of manufacturing aluminium electrode foil for electrolyte capacitors |
| US3963594A (en) * | 1975-06-03 | 1976-06-15 | Aluminum Company Of America | Electrochemical treatment of aluminum surfaces with an aqueous solution of hydrochloric acid and gluconic acid |
| US4292148A (en) * | 1980-08-07 | 1981-09-29 | Sprague Electric Company | Post-treatment of etched aluminum capacitor foil |
| US4332651A (en) * | 1981-05-20 | 1982-06-01 | Sprague Electric Company | AC Etching of aluminum capacitor foil |
| US4566959A (en) * | 1984-01-05 | 1986-01-28 | Hoechst Aktiengesellschaft | Process for the electrochemical roughening of aluminum useful for printing plate supports, in an aqueous mixed electrolyte |
| KR100376984B1 (en) * | 1998-04-30 | 2003-07-16 | 주식회사 하이닉스반도체 | Photoresist polymer and method for forming micropattern by using the same |
-
1938
- 1938-01-03 US US183131A patent/US2336846A/en not_active Expired - Lifetime
Cited By (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3108918A (en) * | 1944-01-12 | 1963-10-29 | Harold J Plumley | Trepanning of cased explosives by etching |
| US2472304A (en) * | 1944-03-13 | 1949-06-07 | Aluminum Co Of America | Method of etching aluminum |
| US2598043A (en) * | 1947-02-20 | 1952-05-27 | Reynolds Metals Co | Process of preparing planographic printing plates |
| US2796334A (en) * | 1955-02-23 | 1957-06-18 | Aluminum Co Of America | Etching aluminum |
| US2863811A (en) * | 1955-05-09 | 1958-12-09 | Gen Electric | Method of etching capacitor electrodes |
| US2853445A (en) * | 1956-04-06 | 1958-09-23 | Aerovox Corp | Process of etching aluminum foil for electrolytic capacitor |
| US2964453A (en) * | 1957-10-28 | 1960-12-13 | Bell Telephone Labor Inc | Etching bath for copper and regeneration thereof |
| US2962364A (en) * | 1958-08-15 | 1960-11-29 | Modern Engraving And Machine C | Process and composition for developing images and designs on metal |
| US3075894A (en) * | 1959-01-23 | 1963-01-29 | Westinghouse Electric Corp | Method of electroplating on aluminum surfaces |
| US3072546A (en) * | 1959-03-02 | 1963-01-08 | Lawton Printing Company | Graining printing plates |
| US3002899A (en) * | 1959-07-31 | 1961-10-03 | Jr Walter E Reid | Adhesion of nickel to chromium |
| US3284326A (en) * | 1962-04-09 | 1966-11-08 | Sprague Electric Co | Electrolytic etching of anodisable metal foil |
| DE1240360B (en) * | 1962-08-10 | 1967-05-11 | Siemens Ag | Process for improving oxide layers produced by anodic oxidation on aluminum electrodes |
| US3321389A (en) * | 1964-07-20 | 1967-05-23 | Mallory & Co Inc P R | Method of anodically etching aluminum foils at elevated temperatures in an electrolyte including chloride and sulfate ions |
| US3755115A (en) * | 1970-01-02 | 1973-08-28 | Philips Corp | Method of manufacturing aluminium electrode foil for electrolyte capacitors |
| US3963594A (en) * | 1975-06-03 | 1976-06-15 | Aluminum Company Of America | Electrochemical treatment of aluminum surfaces with an aqueous solution of hydrochloric acid and gluconic acid |
| US4292148A (en) * | 1980-08-07 | 1981-09-29 | Sprague Electric Company | Post-treatment of etched aluminum capacitor foil |
| US4332651A (en) * | 1981-05-20 | 1982-06-01 | Sprague Electric Company | AC Etching of aluminum capacitor foil |
| US4566959A (en) * | 1984-01-05 | 1986-01-28 | Hoechst Aktiengesellschaft | Process for the electrochemical roughening of aluminum useful for printing plate supports, in an aqueous mixed electrolyte |
| KR100376984B1 (en) * | 1998-04-30 | 2003-07-16 | 주식회사 하이닉스반도체 | Photoresist polymer and method for forming micropattern by using the same |
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