US3563862A - High precision anodizing of thin films - Google Patents

High precision anodizing of thin films Download PDF

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Publication number
US3563862A
US3563862A US773185A US3563862DA US3563862A US 3563862 A US3563862 A US 3563862A US 773185 A US773185 A US 773185A US 3563862D A US3563862D A US 3563862DA US 3563862 A US3563862 A US 3563862A
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United States
Prior art keywords
electrolyte
resistance
measurement
pad
anodization
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Expired - Lifetime
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US773185A
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English (en)
Inventor
Jean Joly
Georges Dubois
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Lignes Telegraphiques et Telephoniques LTT SA
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Lignes Telegraphiques et Telephoniques LTT SA
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/04—Anodisation of aluminium or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/005—Apparatus specially adapted for electrolytic conversion coating

Definitions

  • Anodization is carried through a movable arm carrying a pad filled with electrolyte the movement of which is synchronized with the A-C oxidising current.
  • the film surface is dried when the pad is removed.
  • the present invention relates to improvements in processes for the anodization of thin-film devices and more particularly to the control of this operation. It is well known to produce devices from thin metal films deposited upon insulating substrates. These devices alford such advantages from the view-point of overall dimensions and reliability that their industrial development has been very rapid in recent years. Such devices consist mainly in metal deposits produced by evaporation in vacuo, by cathode sputtering or by any other method known per se. These films, which are very thin, are relatively sensitive to weathering agents, and a protective oxide layer is employed to passivate the surface. This protection is often afforded through anodization.
  • a simple method of controlling the degree of oxidation consists in measuring the resistance of the layer in the course of the operation. When the operation is automatic, the measurement permits to limit its duration.
  • the component consists of a patterned thin metal deposit on a non-conductive support.
  • a coarse adjustment of the value of the resistance is effected by means of the parameters defining the deposit: geometrical shape, thickness, etc.
  • the precise adjustment of the value of the resistance is effected by anodizing the resistive layer.
  • the present invention is aimed at increasing the precision of the anodization control by increasing the precision of the dynamic resistance measurement during oxidation. It is mainly characterised in that it makes it possible to eliminate the measurement error due to the presence of electrolyte on the surface of the film the resistance of which is being controlled.
  • the present invention has for its object to eliminate the influence of the electrolyte during the measurement, and it is essentially characterised in that the layer to be anodized is only in contact with the electrolyte during the time when it acts as an anode, the said layer being electrolyte-free during the measuring time.
  • the resistor to be adjusted which consists of a metal deposit of given pattern on an insulating substrate 1.
  • the terminal contacts of the metal deposit are connected, generally by soldering, to two leads .2, 2'. These two leads are connected through a switch (not shown) to the resistance measuring circuit (not shown), for example a measuring bridge of a type known per se.
  • the switch makes it possible, to interconnect the lead 2 to a first output terminal of an alternatingcurrent supply source.
  • the switch is so designed as to connect the resistor to the said terminal during the halfcycles in which the latter is positive in relation to the second terminal of the same supply.
  • a pad 3 filled with electrolyte is mounted on the core 4 of an electromagnet 5 which is supplied with alternating current synchronized with the supply source serving for the oxidation.
  • Pad 3 is connected to the second supply terminal.
  • the winding of the electromagnet is so chosen that the pad is in contact with the layer to be anodized during the half-cycles in which the oxidation occurs. It is removed from the resistor as shown in the figure during the half-cycle in which no oxidation is performed and during which the measurement of the resistance takes place. It is to be understood that the alternating displacement of the core may be controlled at any frequency provided that the oxidation current and the movement of the core are synchronous.
  • the pad 3 consists of felt, plastic foam, eider chamois skin or any other porous material which does not leave any fluff and which is filled with 0.1% aqueous orthophosphoric acid solution, the refilling with electrolyte being effected by injection of liquid controlled by an electromagnetic valve every 3 minutes.
  • the alternating-current supply source is a source whose frequency is between 15 and c./s. The frequency is chosen as a function of the range of resistance values to be obtained.
  • the result of the measurement may be used for automating the operation.
  • the resistance value to be reached is stored in a memory, and the measured value may be compared with the desired value, there being derived from this comparison an error signal which serves to control the anodic oxidising circuit either on an on-off basis or progressively, for example by control of the anodic oxidation voltage.
  • the same result would be obtained by displacing, the thin-film circuit, such as the resistor ,1 described in the foregoing instead of the electrolyte filled pad.
  • the thin-film circuit such as the resistor ,1 described in the foregoing instead of the electrolyte filled pad.
  • withdrawal of the pad may be insufficient.
  • the drying may be etfected, for example, by means of a jet ;of dry hot air blown onto the surface during the withdrawal of the buffer.
  • the thin film device When the thin film device is displaced, its own movement may be utilised to remove any electrolyte remaining on the surface through mechanical force.
  • a process for controlling the resistance of a thin metallic film during anodization thereof comprising the following steps:

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Measurement Of Resistance Or Impedance (AREA)
  • Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
  • Apparatuses And Processes For Manufacturing Resistors (AREA)
US773185A 1967-11-10 1968-11-04 High precision anodizing of thin films Expired - Lifetime US3563862A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR127648 1967-11-10

Publications (1)

Publication Number Publication Date
US3563862A true US3563862A (en) 1971-02-16

Family

ID=8641505

Family Applications (1)

Application Number Title Priority Date Filing Date
US773185A Expired - Lifetime US3563862A (en) 1967-11-10 1968-11-04 High precision anodizing of thin films

Country Status (6)

Country Link
US (1) US3563862A (enrdf_load_stackoverflow)
BE (1) BE723227A (enrdf_load_stackoverflow)
DE (1) DE1808103B2 (enrdf_load_stackoverflow)
FR (1) FR1554760A (enrdf_load_stackoverflow)
GB (1) GB1243830A (enrdf_load_stackoverflow)
NL (1) NL6815523A (enrdf_load_stackoverflow)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4085026A (en) * 1975-06-13 1978-04-18 Imperial Metal Industries (Kynoch) Limited Anode assembly for electrodeposition cell
US5184550A (en) * 1990-03-01 1993-02-09 Heidelberger Druckmaschinen Ag Device for controlling wetting behavior of metal surfaces by application of electrolyte under controlled voltage

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2702207C2 (de) * 1977-01-20 1984-01-12 Robert Bosch Gmbh, 7000 Stuttgart Verfahren und Vorrichtung zum Abgleich elektronischer Schaltungen
DE2908361C2 (de) * 1979-03-03 1985-05-15 Dynamit Nobel Ag, 5210 Troisdorf Verfahren zum Erhöhen des Widerstandes elektrischen Zündelementen

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4085026A (en) * 1975-06-13 1978-04-18 Imperial Metal Industries (Kynoch) Limited Anode assembly for electrodeposition cell
US5184550A (en) * 1990-03-01 1993-02-09 Heidelberger Druckmaschinen Ag Device for controlling wetting behavior of metal surfaces by application of electrolyte under controlled voltage

Also Published As

Publication number Publication date
FR1554760A (enrdf_load_stackoverflow) 1969-01-24
BE723227A (enrdf_load_stackoverflow) 1969-04-01
GB1243830A (en) 1971-08-25
NL6815523A (enrdf_load_stackoverflow) 1969-05-13
DE1808103B2 (de) 1971-05-19
DE1808103A1 (de) 1969-09-25

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