This is a brief description of our Gold/Tin plating process to achieve a 75% Au/25% Sn finish:

• This alloy can be useful in opto-electronic and semiconductor applications, and as a lead-tin solder replacement.  It is suitable for plating pre-forms and larger featured surface areas, such as the front and back side of wafers.
• This alloy can be plated on copper, nickel, or silver.  We recommend nickel/silver/gold-tin.
  Thickness' vary depending on use.  We see ranges from 25 uin and up.
• Note: This is a very difficult alloy to plate and it requires numerous set up panels to establish the correct plating cycle to achieve the desired ally composition.