Direct Immersion Gold Plating on Molybdenum and its Alloys
Original Publication Date: 1980-Nov-01
Included in the Prior Art Database: 2005-Feb-14
The molybdenum (Mo) surface is immersed in a chloroauric acid solution at 65 degrees C for less than about 10 minutes. The surface is then rinsed, dried and annealed in forming gas at a temperature of 1000-1050 degrees C for a period of 30 minutes. The resulting surface is solder wettable. Solder wettabilities for 50:50 lead-indium of 75 (pure Au= 92) have been achieved. Alternatively, a lower temperature process is possible which consists of a ten minute 61 degrees C immersion of Mo in a chloroplatinic acid solution, rinse, dry and anneal at 750 degrees C for less than 30 minutes, followed by the above-described chloroauric acid treatment. The process continues with a 750 degrees C treatment for ~ 15 minutes in forming gas. Lead-indium wettabilities of less than 73 were achieved.