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Electroless plating is an important process in printed circuit board and electronics manufacturing but typically requires temperatures of 70‐95°C to give a suitable deposition rate. This is becoming problematic in industry due to the rising price of energy and is a major contribution to production costs. Previous studies have noted beneficial effects of ultrasonic irradiation upon electroless plating processes and it has been reported that sonication can increase the plating rate and produce changes to the chemical and physical properties of the deposited coating. The purpose of this paper is to reduce the operating temperature of an electroless nickel bath by introducing ultrasound to the process.

The deposition rate of an electroless nickel solution was determined by two techniques. In the first method, test coupons were plated in an electroless nickel solution at temperatures ranging from 50‐90°C and the plating rate was calculated by weight gain. In the second approach the mixed potential (and hence the current density at the mixed potential) was determined by electrochemical analysis of the anodic and cathodic reactions. In both cases the plating rate was found with and without the application of an ultrasonic field (20 kHz). The electroless nickel deposits obtained in the plating tests were also analysed to determine the phosphorus content, microhardness and brightness.

The plating rates under ultrasonic agitation were always higher than under “silent” conditions. Most importantly, considering the objectives of this study, the deposition rate under sonication at 70°C was significantly higher than that found with mechanical agitation at 90°C. In addition, the results indicated that the deposits produced in an ultrasonic field had consistently lower phosphorus content, higher microhardness and were brighter than those prepared in an electroless nickel bath that was not sonicated.

Although previous work has been performed on the effect of ultrasound on electroless plating, all these studies have been carried out at the normal operating temperature of the electroless process. In this paper, ultrasound has been applied at temperatures well below those normally used in electroless nickel deposition to determine whether sonication can enable low temperature electroless plating.

The purpose of this paper is to explore the optimum average current density and pulse width for electrodeposition of gold in citrate electrolyte, and it is verified that the uniformity of film thickness can be effectively improved by periodic pulse reverse electroplating.

Apply forward pulse current, forward group pulse current and periodic pulse reverse current to the electrolyte and compare the film quality. High-frequency group pulses are used in both forward and reverse directions of the periodic pulse reverse current.

It is verified by experiments that periodic pulse reverse plating is superior to forward pulse plating and forward group pulse plating in terms of particle size, compactness, impurity content and thickness uniformity of the film. Add low-frequency vibration to the cathode under the same pulse electrical parameters as a comparative experiment to prove the beneficial effect of vibration on the allowable limiting current density and plating rate.

Gold film is often used as the sealing layer of precision parts. Increasing the thickness uniformity and improving the compactness of gold film will help to reduce the size error, improve the subsequent assembly accuracy and increase the service life of wear-resistant layer. Citrate gold plating electrolyte combines the advantages of cyanide electrolyte and cyanide-free electrolyte. Hence, this research focuses on the characteristics of periodic pulse reverse plating in terms of particle size, compactness, impurity content and thickness uniformity of the film and compare it with forward pulse plating and forward group pulse plating.

The purpose of this paper is to solve the issue of via filling and pattern plating simultaneously by concentration optimization of accelerator and leveler in the electroplating bath.

This paper designs a series of experiments to verify the performance of pattern plating with the via filling plating formula. Then the compositions of electroplating solution are optimized to achieve via filling and pattern plating simultaneously. Finally, the mechanism of co-plating for via and line is discussed in brief.

To achieve excellent performance for via filling and pattern plating simultaneously, proportion of additives are comprehensively considered in optimization of electroplating process. Effects of additives on the via filling and pattern plating should be taken into consideration, especially in achieving flat lines.

This paper discusses the different effects of accelerator and leveler on the via filling and the pattern plating, respectively. The process of co-plating for the via and the line is presented. The superfilling of via and the flat line are simultaneously obtained with the optimized via filling formula.

BIGNESS presents its own problems, as those engaged in overhauling Boeing 747 aircraft have already discovered. Take as an example, the problem of overhaul cadmium plating the wing outer cylinder on the main landing gear. This component is nearly 10 ft long and approximately 5 ft across, with a surface of approximately 100 square feet requiring electroplating. It was originally plated in a tank 5 ft by 6 ft by 12 ft deep, containing over 2500 gallons of solution. A tank of this capacity holds over $5000 worth of cadmium solution and nearly $15 000 worth of anodes. It requires a power supply of at least 7500 amperes. Total cost of such an installation, including cleaning and rinsing tanks, aproximates $50,000. Is any company willing to invest $50 000 in a new plating line required only to refinish one or two wing outer cylinders per month? Or, are they prepared to pack up large, cumbersome components, ship over long distances for outside plating, and wait impatiently for their return?

Electroless plating treatment is one surface modification technique. An added effect due to electroless plating is expected, and the vibration damping capacity of the structures may be improved by this technique. In the present study, the vibration damping capacity of such electroless plated structures is measured experimentally. Damping capacity can be improved regardless of the plated film materials. Improvement efficiency with an electroless plating film with dispersed foreign particles such as SiC ceramics is higher than with a uniform electroless plating film.

Sn‐Pb and Sn‐Ag bumps (130 μm diameter, 250 μm pitch) made using an electroplating process were studied. As a preliminary experiment, the effects of current density and plating time on the Sn‐Pb and Sn‐Ag deposits were investigated. The morphology and composition of the plated surface were examined using scanning electron microscopy. The shape and thickness of the solder bumps were also compared. Bump shear testing was performed to measure the adhesion strength between the solder bumps and the under bump metallurgy. In electroplating, the Sn‐Ag plating thickness was proportional to the current density, while plated Sn‐Pb thickness saturated above the limiting current density. The optimal conditions for solder bump fabrication were found at 6 A/dm² for 3 h in the case of Sn‐Pb bump plating and 6 A/dm² for 1 h for the Sn‐Ag bump plating. The bump shear strength for Sn‐Ag was found to be higher than that of Sn‐Pb.

The purpose of this study is to reveal the effect of nano-Al₂O₃ particle addition on the nucleation/growth kinetics, microhardness, wear resistance and corrosion resistance of Co–P–xAl₂O₃ nanocomposite plating.

The kinetics and properties of Co–P–xAl₂O₃ nanocomposite plating prepared by electroplating were investigated by electrochemical measurements, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Vickers microhardness measurement, SRV5 friction and wear tester and atomic force microscopy.

A 12 g/L nano-Al₂O₃ addition in the plating solution can transform the nucleation/growth kinetics of the plating from the 3D progressive model to the 3D instantaneous model. The microhardness of the plating increased with the increase of nano-Al₂O₃ content in plating. The wear resistance of the plating did not adhere strictly to Archard’s law. An even and denser corrosion product film was generated due to the finer grains, with a high corrosion resistance.

The effect of different nano-Al₂O₃ addition on the nucleation/growth kinetics and properties of Co–P–xAl₂O₃ nanocomposite plating was investigated, and an anticorrosion mechanism of Co–P–xAl₂O₃ nanocomposite plating was proposed.

Optimized plating conditions, included proper designs of insulating shield (IS), auxiliary cathode (AC) and different patterns, contribute to the uniformity enhancement of copper deposition.

Plating experiments were implemented in vertical continuous plating (VCP) line for manufacturing in different conditions. Multiphysics coupling simulation was brought to investigate and predict the plating uniformity improvement of copper pattern. In addition, the numerical model was based on VCP to approach the practical application.

With disproportionate current distribution, different plating pattern design formed diverse copper thickness distribution (CTD). IS and AC improved plating uniformity of copper pattern because of current redistribution. Moreover, optimized plating condition for effectively depositing more uniformed plating copper layer in varied pattern designs were derived by simulation and verified by plating experiment.

The comparison between experiment and simulation revealed that multiphysics coupling is an efficient, reliable and of course environment-friendly tool to perform research on the uniformity of pattern plating in manufacturing.

The purpose of the investigation was to research the best process of electroless nickel (EN) plating on AZ91D magnesium alloy and the performance of EN plating coating.

Through single factor test and orthogonal test, EN plating on AZ91D magnesium alloy was researched. The plating rate and porosity were analyzed. The coating appearance of EN plating coating and magnesium alloy substrate was evaluated. The electrochemical properties of EN plating coating and substrate were researched using electrochemical workstation, and their compositions and structure were examined using X-ray diffraction and scanning electron microscopy.

The results made by combination of experimental and orthogonal test showed that the best formula of EN plating was 8.8 g·L⁻¹ nickel ion, 25 g·L⁻¹ lactic acid, 28 g·L⁻¹ reducing agent, 1.8 ml·L⁻¹ corrosion inhibitor, 1 mg·L⁻¹ stabilizer, temperature at 85°C and pH value at 5.5. The plating was uniform, dense and with no cracks. The electrochemical tests showed that the corrosion resistance of EN plating was better than that of magnesium alloy substrate.

The results indicated that the corrosion resistance of magnesium alloy improved markedly after EN plating at the best formula and the plating covered magnesium alloy completely.

This characteristic is important enough in aircraft maintenance to be covered separately. Considerably less embrittlement than that in bath plating is realized in selective plating. With one proprietary solution, Cadmium LHE (Code SPS 5070), hydrogen embrittlement is almost negligible. Selectively plated nickel and nickel‐tungsten alloys also can be plated with so little hydrogen content that no baking for embrittle‐content that no baking for embrittlement relief is required.