Initial Deposition Morphologies of Electroless Nickel-Phosphorus Plating on a Nonconductor and a Conductor

Electroless nickel initial deposition and subsequent steady state deposition process on a nonconductor and conductor were investigated.It is indicated that phosphorus contents in the deposited films during the initial nickel deposition reaction were higher than the subsequent steady state deposited films. The plating baths containing acetic acid, propionic acid, succinic acid, malic acid, citric acid, glycine and aspartic acid as a complexing agent showed higher phosphorus in the deposited films.On the conductor, lactic acid and glycolic acid added bath showed the shortest induction time and deposited films readily changed to continuous films at the initial deposition steps. Also, it is confirmed that a bath exhibiting a higher deposition rate compared with a basic bath leads to extraneous particles during the initial deposition period.On the nonconductor, the morphology of initially deposited nickel was not a layer-by-layer structure on nonconductor, it is confirmed that deposited films are composed of fine particles. Also, particle sizes of nickel-phosphorus deposits ranged from 10 to 40nm.