ELECTROLESS DEPOSITION

Electroless plating uses a redox reaction to deposit metal on an object without the passage of an electric current. Because it allows a constant metal ion concentration to bathe all parts of the object, it deposits metal evenly along edges, inside holes, and over irregularly shaped objects which are difficult to plate evenly with electroplating. Electroless plating is also used to deposit a conductive surface on a nonconductive object to allow it to be electroplated. This plating technique is to prevent corrosion and wear. 

Electroless has several advantages:

  1. Does not use electrical power.
  2. Even coating on the parts’ surface can be achieved.
  3. No sophisticated jigs or racks are required.
  4. There is flexibility in plating volume and thickness.
  5. The process can plate recesses and blind holes with stable thickness.
  6. Chemical replenishment can be monitored automatically.
  7. Complex filtration method is not required
  8. Matte, Semi Bright or Bright finishes can be obtained.

Applications of electroless plating include oil field valves, rotors, drive shafts, paper handling equipment, fuel rails, optical surfaces for diamond turning, door knobs, kitchen utensils, bathroom fixtures, electrical/mechanical tools and office equipment. It is also commonly used as a coating in electronics printed circuit board manufacturing, typically with an overlay of gold to prevent corrosion. This process is known as electroless nickel immersion gold.