Electroless nickel plating

About: Electroless nickel plating is a research topic. Over the lifetime, 1593 publications have been published within this topic receiving 14940 citations.

Method for removing phosphorus and nickel in electroless nickel-plating wastewater and treatment system

Abstract: The invention discloses a method for completely removing phosphorus and nickel in electroless nickel-plating wastewater with advantages of low energy consumption and capacity of avoiding secondary pollution and an adopted treatment system. The nickel-plating wastewater with total phosphorus concentration of 3000mg/L and nickel concentration of 700mg/L is treated into effluent of reaching the standard with the total phosphorus concentration of less than 0.5ppm and nickel concentration of less than 0.1ppm. According to a three-dimensional electrolytic technology, hypophosphorous acid and phosphorous acid in the electroless nickel-plating wastewater can be oxidized into orthophosphoric acid, and nickel ions in a complex state are released. Due to dual oxidation and multiple mixed sludge precipitation reactions, the hypophosphorous acid and phosphorous acid can be further oxidized, the nickel ions in a free state are precipitated, finally the residual nickel ions in the wastewater are completely removed by an ion exchange column, and the effluent reaches the emission standard. Therefore, the pollutants in the electroless nickel-plating wastewater can be totally controlled, the national emission standard is continuously and stably reached, the treated sludge containing nickel and phosphorus is subjected to after-treatment, and the nickel and phosphorus can be effectively recovered.

Electroless nickel immersion gold semiconductor flip chip package

Abstract: A flip chip package, apparatus and technique in which a ball grid array composed of a doped eutectic Pb/Sn solder composition is used. The dopant in the Pb/Sn solder forms a compound or complex with the phosphorous residue from the electroless nickel plating process that is mixable with the Pb/Sn solder. The phosphorous containing compound or complex prevents degradation of the solder/under bump metallization bond associated with phosphorus residue. The interfacial solder/under bump metallization bond is thereby strengthened. This results in fewer fractured solder bonds and greater package reliability.

Simultaneous removal of nickel and phosphorus from spent electroless nickel plating wastewater via calcined Mg–Al–CO3 hydroxides

Abstract: For electroless nickel plating wastewater, a novel approach for the simultaneous removal of nickel and phosphorus on calcined Mg–Al–CO3 hydroxides (CLDHs) is proposed. The dependence of the adsorption efficiency on several parameters, including initial ions' concentration, temperature, contact time and pH, has been investigated with batch experiments. The adsorption kinetics data of nickel and phosphorus could be well depicted by a pseudo-second-order model. Adsorption isotherms studies showed that the uptake of nickel and phosphorus on CLDHs followed Langmuir and Freundlich models, respectively, and that the maximum removal of nickel or phosphorus was up to 22.87 or 761.5 mg g−1. Thermodynamic analyses implied that the adsorption process of nickel or phosphorus on CLDHs was spontaneous and endothermic. Further, the possible mechanisms were explored in: low concentration solutions, CLDHs took part in reconstitution involving the isomorphous substitution of nickel at the magnesium sites in sheets and by the concomitant utilization of phosphorus by the generated superficial sheets; and in high concentration solutions, the CLDHs rebuilding hydrotalcite structures were influenced and formed mixed metal salts of phosphites, hydroxides, and hypophosphites, which were attributed to the presence of plentiful phosphorus and brought about the reduced uptake of nickel.

Activation of copper surfaces in chemical deposition of composite nickel coatings

Abstract: Electroless nickel plating of copper surfaces has perspective application both in electronics (for deposition of the final two layered NiP/Au coating on contact copper spots of printing circuit cards) and in microtechnique (for preparation of microstructures). Copper and its alloys do not exert any catalytic effect on the main redox reaction running in electrolytes for electroless nickel plating and therefore their preliminary activation is required. The present paper summarises the experimental results obtained with activation of copper surfaces using solutions containing palladium ions and a complexant. The optimum concentration of the activating solutions and operation conditions are established, providing uniform NiP coatings of sufficient thickness and good morphology. A special attention is paid to the deposition of composite NiP–TiO2 coatings. The electroless nickel plating is performed in electrolytes comprising NiSO4.7H2O, NaH2PO2.H2O, complex forming and buffering substances, stabilisers...

Optical product and its manufacture

Abstract: PROBLEM TO BE SOLVED: To reduce the cost of a product and to improve the productivity thereof by suppressing the occurrence of the defect on an electroless nickel plating surface layer. SOLUTION: The optical product 1 includes a base body 2, the electroplating layer 4 which is formed on this base body 2 and has a smoothing effect and the electroless nickel plating layer 5 which is formed on this electroplating layer 4. Even if very small dents, holes, etc., exist on the surface 3 of the base body 2, the electroplating layer 4 formed on the surface 3 of the base body 2 is provided with the smooth surface. As the electroless nickel plating layer 5 is formed on the smooth surface of the electroplating layer 4 and, therefore, the occurrence of the defect in the electroless nickel plating layer 5 is suppressed.