Advantage and Disadvantages Compared to Electroplating

1) Eliminating the need for a counter electrode in electroless plating has a profound influence, on the current distribution. Macro-throwing power is no longer an issue, because primary current distribution is caused by the nonuniformity of the electrostatic field between the object being plated and the counter electrode. Since there is no counter electrode, uniformity of plating on complex shapes can readily be achieved. 

3) In contrast, during electroplating both macro-and micro-throwing power play a role. Moreover, since the plated layer is relatively thick (compared to that produced by electroless plating), the current density is higher, in order to increase production rate, and suitable additives are used to improve uniformity of thickness, as well as brightness and smoothness. 

4) The most important feature of electroless deposition is that it can be performed on nonconducting surfaces, such as plastics, glass, semiconductors and ceramic materials. Special surface treatments are needed in order to activate the surface, and good adherent thin metallic surfaces can be produced, which can be followed by electroplating of the same or a different metal. 

5) The weak point in electroless plating is that the solution is inherently unstable (since it is this thermodynamic instability that allows the bath to operate). The composition of the bath must be such that it will be stable in the bulk of the solution, and reduction of the metal will only occur on the surface that has been activated. Thus, maintaining uniformity of the product can be much more of a challenge in electroless plating than in electroplating. Nevertheless, electroplat- 

6) Electroless plating is usually limited to very thin layers, typically less than 1 im. This could be an advantage, when the purpose is to create a very thin barrier layer. When a protective layer is needed (to prevent corrosion or abrasion) this is an obvious disadvantage. This, however, is not an inherent limitation of the method, and it would seem that technologies for electroless plating of thicker layers could be developed. 

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