Use of hydroxy carboxylic acids as ductilizers for electroplating nickel-tungsten alloys
AssigneeEnthone-OMI, Inc.
InventorWalter J. Wieczerniak
Life of this patent
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Abstract
A process for tungsten alloy plating wherein a tungsten replenisher concentrate of tungsten ions pre-complexed with a hydroxy carboxylic acid is used for maintenance additions to the bath. A preferred additive includes from about 100 to about 120 g/l of tungsten ions complexed with from about 120 to about 220 g/l of citric acid. The process provides consistent cathode efficiency and produces ductile deposits of tungsten alloy electroplate.
Claims20
A process for continued electroplating of tungsten alloys with greater cathode efficiency and producing improved ductile deposits comprising electroplating of a tungsten alloy plate from a bath comprising:
- an effective amount of tungsten ions;
- an effective amount of metal ions selected from the group consisting of nickel, iron, cobalt and mixtures thereof;
- an effective amount of a hydroxy carboxylic acid and an effective amount of ammonium ions;
- and
- replenishing the above bath with tungsten ions by addition of an effective amount of a tungsten replenishing additive consisting essentially of ionic tungsten complexed with a hydroxy carboxylic acid prior to addition to the bath, said effective amount being sufficient for restoring tungsten ion concentration which was depleted from the bath during electroplating, whereby the cathode efficiency is improved and the ductility of the deposit is improved.
A process for replenishing a tungsten alloy electroplating bath with tungsten metal comprising:
- (1) providing a suitable tungsten alloy electroplating bath;
- (2) electroplating a tungsten alloy onto a cathodic element;
- and
- (3) making replenishing additions of tungsten ions to the bath by first preparing a complexed tungsten additive consisting essentially of tungsten ions and a hydroxy carboxylic acid having from 1-6 carbon atoms, and adding this complexed tungsten additive to the bath for replenishing the bath.
A process for replenishing tungsten ions in a tungsten alloy electroplating bath comprising:
- (1) providing a tungsten alloy electroplating bath including an effective amount of tungsten ions;
- an effective amount of metal ions selected from the group consisting of nickel, iron, cobalt and mixtures thereof;
- an effective amount of a hydroxy carboxylic acid;
- and an effective amount of ammonium ions;
- (2) electroplating a tungsten alloy from the electroplating bath;
- and
- (3) replenishing tungsten ions in the bath with a concentrate mixture consisting essentially of from about 50 to about 220 grams of tungsten ions, and from about 100 to about 200 grams of citric acid.
Dependencies are inferred from the claim text.