Nucleation of Metals on Aluminum by Laser Irradiation and the Effect on Ni‐P Electroless Deposition

Abstract

The mechanism of direct Ni‐P electroless deposition on aluminum by pulsed yttrium aluminum garnet (YAG) laser irradiation in solution was investigated by X‐ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) with energy‐dispersive X‐ray (EDX) analysis. Aluminum specimens covered with porous anodic oxide films were irradiated with a pulsed YAG laser in solutions containing , , , or ions, and then localized Ni‐P electroless plating was attempted at the laser irradiated area in solution. It was found that laser irradiation in solutions containing , , or ions causes the deposition of small metallic particles of Pd, Cu, or Ni at the laser‐irradiated area on the aluminum surface which was exposed to the solution after removal of anodic oxide film. The deposition of the metals is due to a redox reaction between the aluminum substrate and the , , or ions. During laser irradiation in solution, Ni‐P and Ni were deposited by redox reactions between and as well as between and Al. Palladium and nickel (Ni‐P) particles deposited during the laser irradiation acted as catalytic centers for the subsequent Ni‐P electroless plating, while Cu particles did not promote the electroless plating. © 1999 The Electrochemical Society. All rights reserved.