Plating method by means of an electroless gold plating solution and system therefor
AssigneeElectroplating Engineers of Japan Limited
InventorsTakayuki Sone, Hiroshi Wachi
Life of this patent
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Abstract
A plating method by means of an electroless gold solution under air supply in the form of air bubbles from air dispersing bodies placed on the bottom of a plating tan, whereby more uniform plating can be achieved and the life of the plating solution can be prolonged. Air bubbles are uniformly supplied over the entire region in the plating tank which corresponds to a plating region of a substance to be plated and placed in the plating tank, and the air supply is adjusted depending on the liquid temperature of the plating solution.
Claims6
A plating method by means of an electroless gold plating solution, comprising the steps of:
- filling a first tank with said electroless gold plating solution for gold plating parts positioned in said first tank;
- injecting air over a wide enough area at the bottom of said first tank for forming air bubbles that rise uniformly into the region of said first tank where said parts are positioned for gold plating, for surrounding said parts with air bubbles;
- maintaining a plating temperature substantially higher than the storage temperature of said electroless gold plating solution for periods of time between plating operations;
- and
- adjusting the flow rate of injected air at a given plating temperature, while maintaining substantially uniform plating, whereby said adjusting step includes the step of reducing the flow rate of injected air to a substantially lower flow rate relative to that used at plating temperatures, at times that the temperature of said electroless gold plating solution is at the lower storage temperature, whereby the ratio of the flow rate of air used at plating temperatures to the flow rate of air used at storage temperatures is ten to one.
Dependencies are inferred from the claim text.