What Is Electroless Plating?

Electroless plating is a process to produce thin metallic coatings on objects without the application of external current. The advantages of this process over electroplating are the possibility to produce coatings on insulator materials, and to produce uniform thickness coatings on geometrically complex surfaces. The first description of electroless plating was that of Von Liebig involving the reduction of silver salts by reducing aldehydes [1]. Modern electroless plating began in 1946 with the rediscovery by Brenner and Riddell, that hypophosphite could bring about nickel deposition [2]. The first electroless nickel solution capable of wide use on plastics was introduced in 1966; As aforementioned, the electroless plating process is achieved to improve the mechanical properties of

Thiourea accelerates the rate of deposition up to (0.8 ppm) and started to inhibit at a concentration of (1ppm) [4-6]. Mild steel was electroless coated with nickel–phosphorus alloy from a bath containing sodium hypophosphite and glycin–citrate complexing agents, the effect of coating time on phosphorus content, thickness, structure and hardness of the deposits were also analyzed [7].

In the literatures, very few papers have been reported investigating the effect of UV on the electroless plating process. Moreover, all the papers have been found dealing with the polymer substrates. On the other hand, it has also been reported that the electroless plating rate of nickel was suppressed by UV irradiation onto the substrate removed from the sensitizer solution [8]. Additionally, the UV irradiation was used in an electroless plating solution of nickel, where it was suppressed the plating rate significantly [9]. It is expected that these techniques will be applied to make metal film patterns on printed circuits. The effect of UV irradiation on nickel plating during the electroless plating process was investigated.