Patent ID: 11898264
Assignee: HUTCHINSON TECHNOLOGY INCORPORATED
Field: Surface technology, coating (Chemistry)
Classification: CPC C | IPC C

Claim 5:
6. A method of electroplating gold onto one or more stainless steel surfaces, the method comprising:
treating at least a portion of one or more surfaces of stainless steel by exposing each of the one or more surfaces of stainless steel to a solution comprising potassium permanganate (KMnO4) and sodium hydroxide (NaOH), the one or more surfaces of stainless steel including a metal circuit layer disposed on the one or more surfaces of stainless steel, wherein a concentration of the potassium permanganate in the etchant solution is between 0.1 M and 0.4 M, and the sodium hydroxide is added until the etchant solution has a pH greater than 12.5;
exposing at least the portion of the one or more stainless steel surfaces to the etchant solution fora period of time between 1 second and 5 minutes and at a temperature between 5.0 and 85 degrees Celsius;
subsequently neutralizing at least the portion of the one or more surfaces of stainless steel by exposing each of the one or more surfaces of stainless steel to a solution comprised of ascorbic acid and citric acid;
exposing at least the portion of the one or more surfaces of stainless steel to an oxygen plasma cleaning process and a wet cleaning process solution;
repassivating at least the portion of the one or more stainless steel surfaces with a chromium oxide layer;
removing the chromium oxide layer using a plating surface treatment operation;
immersing the one or more surfaces of stainless steel in a gold electroplating solution; and
applying a voltage between an anode within the gold electroplating solution and at least the portion of the one or more surfaces of stainless steel to generate a current from the anode to at least the portion of the one or more surfaces of stainless steel to electroplate gold from the gold electroplating solution onto at least the portion of the one or more surfaces of stainless steel.