Electrolytic bath and methods of use

A method for electrolytically removing a metal from an electrically conductive substrate which method comprises employing said substrate as the anode in an electrolytic cell comprising said anode and a cathode immersed in an electrolytic bath comprising sulfuric acid and a chalcogen-containing compound soluble in said bath and having the empoirical formula:

• ##STR5## wherein X is a chalcogen, each of R.sub.1 and R.sub.2 is selected from hydrogen, NR.sub.3 R.sub.4 and NR.sub.5, at least one of R.sub.1 and R.sub.2 is other than hydrogen, each of R.sub.3 and R.sub.4 is selected from hydrogen and monovalent organic radicals, and R.sub.5 is selected from divalent organic radicals, the molar ratio of said chalcogen-containing compound to said sulfuric acid is about 1 to less than 5, and the molar ratio of water to the combination of said sulfuric acid and said chalcogen-containing compound is about 10 or less, and impressing a voltage differential across said cathode and said anode.

A method for electrolytically plating a metal on an electrically conductive substrate, which method comprises suspending said electrically conductive substrate in an electrolytic bath which comprises at least about 10 weight percent sulfuric acid, at least about 10 weight percent of chalcogen-containing compound selected from the group consisting of urea, a formamide, thiourea, and combinations thereof, and a metal ion platable on said substrate wherein the molar ratio of said chalcogen-containing compound to said sulfuric acid is within the range of about 1 to less than 5, and the molar ratio of water to the combination of said chalcogen-containing compound and said sulfuric acid is about 10 or less, and electrolytically plating said platable ion on said substrate.

A method for electrolytically depositing a metal on or removing a metal from a substrate which method comprises conducting said metal deposition or removal in an electrolytic bath comprising sulfuric acid and a chalcogen-containing compound soluble in said bath and having the empirical formula ##STR6## wherein X is S or O, each R.sub.1 and R.sub.2 is selected from hydrogen, NR.sub.3 R.sub.4 and NR.sub.5, at least one of R.sub.1 and R.sub.2 is other than hydrogen, each of R.sub.3 and R.sub.4 is selected from hydrogen and monovalent organic radicals, and R.sub.5 is selected for divalent orgnaic radicals, the molar ratio of said chalcogen-containing compound to said sulfuric acid is about 1 to less than 5, and the molar ratio of water to the combination of said sulfuric acid and said chalcogen-containing compound is about 10 or less.

A method for electrolytically depositing a metal on or removing a metal from a substrate which method comprises the step of conducting said metal deposition or removal in an electrolytic bath comprising sulfuric acid and a chalcogen-containing compound soluble in said bath and having the empirical formula ##STR7## wherein X is S or O, each of R.sub.1 and R.sub.2 is selected from hydrogen, NR.sub.3 R.sub.4 and NR.sub.5, at least one of R.sub.1 and R.sub.2 is other than hydrogen, each of R.sub.3 and R.sub.4 is selected from hydrogen and monovalent organic radicals, and R.sub.5 is selected from divalent organic radicals, the molar ratio of said chalcogen-containing compound to said acid is about 1 to less than 2, and the molar ratio of water to the combination of said acid and said chalcogen-containing compound is about 2.5 or less.

A method for electrolytically depositing a metal on a substrate which comprises employing said substrate as a cathode in an electrolytic cell comprising an anode and said cathode immersed in an anhydrous, electrolytic bath comprising about 10 to about 70 weight percent sulfuric acid and a chalcogen-containing compound soluble in said bath and having the empirical formula ##STR8## wherein X is a chalcogen, each of R.sub.1 and R.sub.2 is selected from hydrogen, NR.sub.3 R.sub.4 and NR.sub.5, at least one of R.sub.1 and R.sub.2 is other than hydrogen, each of R.sub.3 and R.sub.4 is selected from hydrogen and monovalent organic radicals, and R.sub.5 is selected from divalent organic radicals, the molar ratio of said chalcogen-containing compound to said acid being about 1 to less than 5, and depositing said metal on said substrate.

A method for electrolytically depositing a metal on a substrate which comprises employing said substrate as a cathode in an electrolytic cell comprising an anode and said cathode immersed in an anhydrous, electrolytic bath comprising about 10 to about 70 weight percent sulfuric acid and a compound selected from the group consisting of urea, thiourea, formamide, and combinations thereof in which the molar ratio of said compound to sulfuric acid is about 1 to less than 5, and depositing said metal on said substrate.

A method for electrolytically depositing aluminum or titanium on a substrate which method comprises suspending said substrate as a cathode in an electrolytic cell comprising an anode and said cathode immersed in an anhydrous, electrolytic bath comprising about 10 to about 70 weight percent sulfuric acid and a compound selected from the group consisting of urea, thiourea, formamide, and combinations thereof in which the molar ratio of said compound to sulfuric acid is within the range of about 1 to less than 5, and wherein said bath comprises a member selected from the group consisting of aluminum, titanium, and combinations thereof, and depositing said aluminum or titnium on said substrate.

A method for immersion plating platable metal ions on a substrate which comprises a metal which is less noble than said platable metal ions which method comprising suspending said substrate in an electrolyte containing said platable metal ions, sulfuric acid, and a chalcogen-containing compound soluble in said bath and having the empirical formula:

• ##STR9## wherein X is a chalcogen, each of R.sub.1 and R.sub.2 is selected from hydrogen, NR.sub.3 R.sub.4 and NR.sub.5, at least one of R.sub.1 and R.sub.2 is other than hydrogen, each of R.sub.3 and R.sub.4 is selected from hydrogen and monovalent organic radicals, and R.sub.5 is selected from divalent organic radicals, the molar ratio of said chalcogen-containing compound to said sulfuric acid is about 1 to less than 5, and the molar ratio of water to the combination of said sulfuric acid and said chalogen-containing compound is about 10 or less, under conditions sufficient to plate said metal ions on said substrate.