China
Africa
Explore chapters and articles related to this topic
Metal Plating and Surface Finishing
Published in E. Higgins Thomas, Hazardous Waste Minimization Handbook, 2018
After being scrubbed, the board is cleaned and etched to promote good adhesion and then is plated with an additional layer of copper. Since the holes are not conductive, electroless copper plating is employed to provide a thin continuous conductive layer over the surface of the board and through the holes. Electroless copper plating involves using chelating agents to keep the copper in solution at an alkaline pH. Plating depletes the metal and alkalinity of the electroless bath. Copper sulfate and caustic are added (usually automatically) as solutions, resulting in a “growth” in volume of the plating solution. This growth is a significant source of copper-bearing wastewater in the circuit board industry.
Surface modification of ABS polymer by electroless deposition of thin nickel film from a solution without reducing agent
Published in Transactions of the IMF, 2023
V. Chakarova, M. Petrova, E. Dobreva, D. Lazarova, M. Monev
One of the most common metallised polymers with wide application in a number of fields (automotive, sanitary industry, household) are acrylonitrile–butadiene-styrene (ABS) polymers. Before the final metallisation by electrodeposition, the polymer details have to be subjected to a series of pretreatments such as degreasing, etching, reduction, pre-activation, activation, acceleration and electroless deposition of copper or nickel coating.1 Environmental problems in electroless copper plating (the content of toxic formaldehyde in the solution, wastewater purification) have stimulated the development of processes for direct metallisation. A review on different solutions used in this field is given in Dietz.2 For example, instead of the operation acceleration and electroless copper plating, activation with increased concentration of palladium ions in the solution and direct electrodeposition of copper from an electrolyte with a special composition are proposed.3 Investigations are also described,4, 5 where copper ions are added to the accelerating solution, after which copper electrodeposition is conducted until the surface of the polymer substrate is completely covered with a copper coating.
Study of a system for creating a statistical model of the electroless plating of Cu-Ni-P alloys
Published in Transactions of the IMF, 2022
After undergoing the operations of this pretreatment, the samples were subjected to electroless deposition of Cu-Ni-P alloy coating. The composition of the electroless copper plating solution was 5–25 g L−1 CuSO4.5H2O as a copper ion source, 16 g L−1 sodium citrate as a complexing agent, 20–40 g L−1 sodium hypophosphite as a reducing agent and 30 g L−1 boric acid as a buffering agent in the work solution. The pH was adjusted using 10 M NaOH or H2SO4 to a final value of 9.0–9.3. The temperature was held at 70°C. The plating was performed in a 250 mL electroless copper solution with continuous stirring. Nickel ions in the form of 1–10 g L−1 NiSO4.7H2O were added to the working bath to catalyse the oxidation of the reducer. The effect of the concentration of Ni2+ ions added to the electrolyte on the composition and the percentage of Ni included in the deposited Cu-Ni-P alloy coatings was studied. From the author and colleagues’ previous studies6,7 it was found that significantly thick Cu-Ni-P alloy coatings are obtained at a deposition time of 30 min.
Electroless copper plating of dielectrics from environmentally friendly reducer-free electrolyte
Published in Transactions of the IMF, 2021
M. Georgieva, Ch. Girginov, M. Petrova, D. Lazarova, E. Dobreva, S. Kozhukharov
Electroless copper plating is a process of reduction of Cu2+ ions on the surface of various dielectric materials and semiconductors in order to obtain decorative and functional copper coatings. These coatings have found wide application for the formation of conductive patterning, wiring openings in the process of manufacturing printed circuit boards and integrated circuits, as well as for a number of other operations in electrical engineering and electronics.10–13 This is the reason for the extremely large number of different solutions used for the chemical copper plating of dielectrics containing a reducing agent.14–16