Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D3/00—Electroplating: Baths therefor
  • C25D3/02—Electroplating: Baths therefor from solutions
  • C25D3/38—Electroplating: Baths therefor from solutions of copper
  • C25D3/40—Electroplating: Baths therefor from solutions of copper from cyanide baths, e.g. with Cu+

Definitions

• This invention relates to electroplating of copper and more particularly to the electrodeposition of bright copper plates.
• Electrodeposited copper is widely used as a decorative finish and also as an undercoat for subsequent electrodeposits such as nickel baths acceptacle to industry are desirably economic, stable, easy to maintain, and should have good plating characteristics.
• Alkaline-cyanide type baths are widely used because of their relatively high plating speeds, excellent throwing power, and ease of maintenance. Alkaline-cyanide electroplating baths, and processes are described in Modern Electroplating, edited by A. G. Gray, pages 194-225 (1953).
• Another object of the invention is to provide bath compositions of the alkaline-cyanide type from which bright copper plate is electrodeposited.
• Still another object of the invention is to provide compositions of matter which, when dissolved in water, yield alkaline-cyanide electrolytes suitable for the electrodeposition of bright copper electrodeposits.
• the invention contemplates-elem trodepositing copper from an alkaline-cyanide copper plating bath containing a small but effective amount of a compound having the general formula (herein referred to as a selenium bisdithiocarbamate), wherein R and R may be the same or different and are selected from the class consisting of hydrogen and alkyl hydrocarbon groups having up to 6 carbon atoms in the group.
• R and R within the scope of the invention include hydrogen and alkyl groups such as methyl, ethyl, propyl, butyl, amyl and hexyl, and the branched as well as the straight chain groups.
• the R and R groups may be replaced with a single alkyl cyclic compound, which may be viewed as a joinder of the R and R groups and include compounds having a total of to 7 carbon atoms in the ring.
• Selenium bisdiethyldithiocarbamate is the preferred additive.
• Electroplatingt 2 Conventional alkaline-cyanide baths and process conditions for electrodeposition are utilized in the present invention. Typical baths and process are illustrated in the table below: a
• potassium salts noted in the table which are preferred, may be partially or completely replaced by sodium salts.
• the copper electrodeposits obtained from baths utilizing selenium bisdithiocarbamate additions are substantially mirror bright.
• the electrodeposits prepared from the selenium bisdithiocarbamate-containing baths may be obtained in an even brighter condition by utilizing auxiliary or cooperating brightening additives in conjunction with the primary selenium bisdithiocarbamate.
• auxiliary additives include relatively small amounts of salts of lead, bismuth, antimony, or zinc, e. g., lead acetate, bismuth citrate, potassium antimony tartrate, zinc chloride, zinc sulfate, etc.
• the alkaline-cyanide baths utilized should preferably contain a compound selected from the class consisting of the alkali metal tartrates, citrates, gluconates, and saccharates to improve current efiiciencies.
• wetting agents of the kind generally used in alkaline-cyanide copper electroplating baths are preferably incorporated in the baths. These include quaternary amine wetting agents such as C-decylbetaine and the ammonium hydroxide derivatives such as trimethylbenzylammonium chloride.
• the above compounds, marketed under the trade name Deriphats are used-in concentrations of 0.01 to 0.1 gram per liter. They are stable in the electrolyte and even impart some brightening action.
• a compound of this class which has been successfully used is the sodium salt of a coconut alcohol derivative of fl-amino propionate, designated as Deriphat 151.
• the selenium acts as a non-metal, the compounds being analogues of sulphur and/or oxygen-containing compounds, i. e., the selenium atoms were essentially non-metallic in nature.
• An alkyline-cyanide bath for bright copper plating comprising copper cyanide and, as a brightening agent more than 0.001 g./1. of at least one selenium bisdithiocarbarnate having the general formula:
• a bath solution according to claim 1 which also contains an alkali metal gluconate.
• a bath solution according to claim 1 which also contains an alkali metal saccharate.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Electroplating And Plating Baths Therefor (AREA)

Priority Applications (5)

Applications Claiming Priority (1)

Publications (1)

Family

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Family Applications (1)

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Cited By (4)

Citations (4)

• 0
  • DE DENDAT1072449D patent/DE1072449B/de active Pending
• 1957
  • 1957-06-19 US US666766A patent/US2873234A/en not_active Expired - Lifetime
• 1958
  • 1958-06-06 GB GB18210/58A patent/GB836977A/en not_active Expired
  • 1958-06-16 FR FR1198260D patent/FR1198260A/fr not_active Expired

Patent Citations (4)

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