Reactions of Ni-B on printed Ag pattern by using nearly neutral electroless bath

In this study, we investigated the characteristics of a nearly neutral Ni source solution including dimethylamine borane (DMAB) used to develop the metal PCB (printed circuit board) of high power LED (light-emitting diode) package. In accordance with the bath temperature ranging from 50 degrees C to 75 degrees C, an electroless Ni-B plating on a screen-printed Ag pattern with an anodized Al substrate was carried out. The depositon rate of the electroless plated Ni-B film at bath temperature ranging from 50 degrees C to 75 degrees C was estimated by measurements of the thickness and the mass. The deposition rates by change of thickness and mass of the electroless plated Ni-B film at 50 degrees C were - 58 nm/min and 0.113 mg/min respectively. The activation energy obtained from slope of Arrhenius plot using these deposition rates was - 59 kJ/mol. Finally, selectively the film growth was achieved at all plating temperatures, without a damage of anodized Al substrate.