Fabrication of a novel porous Ni–P thin-film using electroless-plating: Application to embedded thin-film resistor

• A porous Ni–P alloy thin-film was electrolessly deposited with addition of MnSO4·H2O in its electrolyte solution to fabricate embedded resistor.
• High density of pores or holes were formed in Ni–P thin-film.
• Sheet resistance of porous thin-film quadratically increases as the concentration of MnSO4H2O increases.
• Resistance tolerance of porous thin-film was lower than 15%.

A novel porous Ni–P alloy thin-film was developed to fabricate embedded resistor through the electroless deposition by introducing manganese ion in electrolyte solutions. SEM images demonstrated high density of pores or holes with diameters ranging from 0.1 μm to 3.0 μm was formed in Ni–P thin-film when the concentrations of MnSO4·H2O changed from 0 to 50 g/dm3. Resistance testing results revealed a significant increasing of resistance as the concentration of MnSO4·H2O increases and thereby a quadratical relationship between them was primly fitted with low deviation of 5.75%. Moreover, to explore the application practice of this porous thin-film in embedded resistor, distribution experiment was designed to investigate resistance tolerance using maximum deviation method. Tolerances under 15% indicated this porous Ni–P thin-film is a very practical candidate to fabricate embedded resistors.