Gold Plating, Electrodeposited


Types contain the minimum level, or purity, of Gold. Pure soft gold, used in wire-bonding, is 99.9% pure and has HK below 90.

  Type  Purity  Grade  Finish
  Type I        99.7% Gold   A, B, or C  Hard Gold  
  Type II       99.0% Gold  B, C, or D  Hard Gold
  Type III  99.9% Gold  Grade A only  Soft Gold


  Grade   Hardness
  Grade A                                Knoop hardness 90 Maximum
  Grade B  Knoop hardness 91-129
  Grade C  Knoop hardness 130-200
  Grade D  Knoop hardness 200+ 

If the hardness grade for the gold coating is not specified, Type I shall be furnished at hardness Grade A (Knoop hardness: 90 max) and Type II shall be furnished at hardness Grade C (Knoop hardness: 130 to 200).


  Class  Minimum Thickness (inches)
  Class 00                                    0.00002 inch thick (min)
  Class 0  0.00003 inch thick (min)
  Class 1  0.00005 inch thick (min)
  Class 2  0.00010 inch thick (min)
  Class 3  0.00020 inch thick (min)
  Class 4  0.00030 inch thick (min)
  Class 5  0.00050 inch thick (min)
  Class 6  0.00150 inch thick (min)

1. Thermal & electrical conductivity
2. Resistance to oxidation
3. Solderable
4. Wire-bondable
5. Infrared reflectivity
6. Heat treatment
7. Masking
8. Plugging