4.B] What is electroless plating? Explain the electroless plating of copper.
Answer:-
Deposition of a metal from its salt solution on a catalytically active surface by a suitable reducing agent without using electrical energy is known as electroless plating’.
Metal ion + Reducing agent → Metal + Oxidized product
Electroless plating of copper on PCB (Printed Circuit Board):
[1] Preparation of the surface: The surface of the plastic is degreased by treating it with an alkali solution and washed with distilled water. The cleaned surface is treated with SnCl2 and PdCl2 alternatively to obtain a catalytically active surface.
[2] Composition of electroless bath:
Reactions:-
