抄録
Electroless indium plating with NaBH4 as a reducing agent has been studied by measuring deposition rates, infrared spectra, thermal analysis curves and cathodic polarization curves. It was found that a metallic grey deposit can be obtained with EDTA as a complexing agent in the pH range of 9.5-10.0. The addition of tri-ethanolamine to the EDTA plating bath was effective in increasing the deposition rate. IR, TG, DTG and DTA data suggested that EDTA complexes indium ions strongly in the bath solution and TEA participates in the stabilization of the complex. The cathodic polarization curves of Pt electrode showed hydrogen evolution peak. The peak height decreases with increasing pH, [In2(SO4)3]/[CEDTA] ratio and In2(SO4)3 concentration, corresponding to decreases in the deposition rate observed for the electroless plating. The deposited film grew up to 0.1μm thickness during one processing and X-ray diffraction indicated the presence of Cu4In.
