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The purpose of this paper is to investigate the effect of TiO₂ nanoparticle content on the corrosion behavior of Ni‐Cr/TiO₂ nanocomposite coatings applied by pulse‐reverse electroplating.

Ni‐Cr/TiO₂ nanocomposite coatings with various contents of TiO₂ nanoparticles were electrodeposited by pulse‐reverse method from a bath containing TiO₂ nanoparticles to be codeposited and citric acid as the complexing agent. The surface morphology and the composition of coatings were studied by scanning electron microscopy (SEM) equipped by energy dispersive X‐ray system (EDS). The corrosion performance of coatings in the 0.5 M NaCl as a corrosive solution was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods.

It was found that the surface of Ni‐Cr/TiO₂ nanocomposite coatings showed a finer structure that was more uniform and compact in appearance than was that of Ni‐Cr coatings. The incorporation of TiO₂ nanoparticles in the alloy coating matrix improved the corrosion performance of the coatings and the higher content of nanoparticles gave better corrosion resistance.

Applying the Ni‐Cr coatings by the pulse‐reverse plating method eliminated cracks that were a problem in the Ni‐Cr alloy coating structure. Furthermore, the corrosion resistance was improved by the addition of TiO₂ nanoparticles to the alloy matrix. This paper reports the optimum plating conditions that gave the better corrosion performance.

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.

Thin coatings are of great importance to minimize corrosion attack of steel in different environments. A review of recent work on electrodeposition and corrosion performance of Zn-Ni-based alloys for sacrificial corrosion protection of ferrous substrates is presented. The purpose of this study is to provide a systematic comparison of the corrosion resistances of Zn-Ni alloy coatings. The review contains key and outstanding comparisons of references for the period from 2007 to 2017. Binary and ternary Zn-Ni-based alloys were compared and contrasted to provide a good knowledge basis for selection of best coating system to steel substrates.

This article is a review article.

Zn-Ni-(X) alloys show great potential for replacing Cd metal in corrosion protection of steel substrates.

The research on plating of binary Zn-Ni alloys from aqueous electrolytes is now well advanced and these alloys show improved corrosion resistance compared to pure Zn. Pulse plated and compositionally modulated multilayer Zn-Ni alloy coatings showed enhanced corrosion properties compared to direct plated Zn-Ni coatings of similar composition.

The work on electrodeposition of Zn-Ni based alloys from ionic liquids is still scarce, yet these liquids show great promise in improving corrosion resistance and reducing coating thickness when compared to aqueous electrolytes. Advanced plating techniques in ionic liquids such as electromagnetic, compositionally modulated multilayer, pulse plating, ternary alloys and composites should be considered as these electrolytes avoid water chemistry and associated defects.

The purpose of this paper is to overview the effect of electroplating current wave forms on Cu filling of through‐silicon‐vias (TSV) for three‐dimensional (3D) packaging.

The paper takes the form of a literature review.

Effective TSV technology for 3D packaging involves various processes such as via formation, filling with conductive material, wafer thinning, and chip stacking. Among these processes, high‐speed via filling without defect is very important for applying the TSV process to industry with a lower production cost. In this paper, the effects of various current forms on Cu electroplating of TSV such as direct current (DC), pulse current (PC), pulse reverse current (PRC), and periodic pulse reverse current (PPR) are described in detail including recent studies.

TSV is a core technology for high density 3D packaging. This paper overviews the recent studies of various current forms on Cu‐filling of TSV.

This paper describes a copper electroplating enabling technology for filling microvias. Driven by the need for faster, smaller and higher performance communication and electronic devices, sequential build up (SBU) technology has been adopted as a viable multilayer printed circuit manufacturing technology. Increased wiring density, reduced line widths, smaller through‐holes and microvias are all attributes of these high density interconnect (HDI) packages. Filling the microvias with conductive material allows the use of stacked vias and via in pad designs. Other potential design attributes include thermal management enhancement and benefits for high frequency circuitry. Electrodeposited copper can be utilized for filling microvias and provides potential advantages over alternative via plugging techniques. The features, development, scale up and results of direct current (DC) and periodic pulse reverse (PPR) acid copper via filling processes, including chemistry and equipment, are described.

Printed circut boards (PCBs) have diminished in size and, simultaneously, their circuit densities have increased. Conventional multi‐layered PCBs have a limitation to higher packaging densities. This paper introduces a new copper electroplating formula that is able to fill vias and through holes simultaneously and is used in a DC plating method, in which the copper thickness deposited on the board surface is relatively very thin after the electroplating is completed.

The uniformity of electrodeposition is the key to successful application of pattern plating because the quality of electrodeposited copper layer has a huge impact on the performance of printed circuit boards (PCBs). The multi-physics coupling technology was used to accurately analyze and forecast the characteristics of electrochemical system. Further, an optimized plating bath was used to achieve a uniform electrodeposition.

A multi-physics coupling numerical simulation based on the finite element method was used to optimize electrodeposition conditions in pattern plating process. The influences of geometric and electrochemical factors on uniformity of current distribution and electrodeposited layer thickness were discussed by multi-physics coupling.

The model results showed that the distance between cathode and anode and the insulating shield had a great impact on uniformity of electrodeposition. By numerical simulation, it had been proved that using an auxiliary cathode was an effective and simple way to improve uniformity of electrodeposition due to redistributing of the current. This helped to achieve more uniform surface of the copper patterns by preventing the edge effect and the roughness of the copper layer was reduced to 1 per cent in the secondary current distribution model.

The research is still in progress with the development of high-performance computers.

A multi-physics coupling platform is an excellent tool for quickly and cheaply studying the process behaviors under a variety of operating conditions.

The numerical simulation method has laid the foundation for the design and improvement of the plating bath.

By multi-physics coupling technology, we built a bridge between theoretical and experimental study for control of uniformity of pattern plating in PCB manufacturing. This method can help optimize the design of plating bath and uniformity of pattern plating in PCB manufacturing.

The improvement of the hydrogen evolution reaction (HER) performance requires more efficient and inexpensive electrocatalysts. The purpose of this study is to prepare Ni-W and Ni-W-P thin films using the electrodeposition technique using a pulse current and investigate their behaviors toward HER in an acidic solution.

The aim is to prepare Ni-W and Ni-W-P films by the electrodeposition technique using a pulse current and estimate their performance for the HER. The surface morphologies and chemical compositions of the deposited films were assessed using scanning electron microscopy, energy-dispersive X-ray analysis and X-ray diffraction. Linear sweep voltammetry, chronoamperometry, Tafel plots and electrochemical impedance spectroscopy were used to evaluate the prepared electrodes toward the hydrogen evolution process.

The main conclusion is that the surface morphology of Ni–W deposited film is a crystalline structure, while that of Ni-W-P deposit is an amorphous structure. HER activity on Ni-W electrodes increases with decreasing the Wt.% of W to 7.83 Wt.% in the prepared electrodes. In addition, the presence of P enhances HER activity, which increases with increasing the Wt.% of P in the prepared Ni-W-P electrodes. Both Ni-W (7.83 Wt.% W) and Ni-W-P (20.34 Wt.% P), which have been prepared at 8 A dm⁻² display the best performance toward HER compared to the other prepared electrodes. They exhibit high catalytic activities toward HER, which is evidenced by high hydrogen evolution current density values of 9.52 and 33.98 mA cm⁻², low onset potentials of −0.73 and −0.63 V, low Tafel slopes of −125 mV/dec, high exchange current densities of 0.058 and 0.20 mA cm⁻², low charge transfer resistances (Rct) of 226.28 and 75.8 ohm·cm² for Ni-W (7.83  Wt.% W) and Ni-W-P (20.34  Wt.% P), respectively; moreover, they exhibited considerable stabilities too.

The results presented in this work are an insight into understanding the performance of the prepared Cu electrodes coated by Ni-W and Ni-W-P films toward HER. In this work, a consistent assessment of the results achieved on laboratory scale has been conducted.

The purpose of this paper is to introduce a new copper electroplating formula which is able to fill blind microvias (BVHs) and through holes (THs) at one process through a direct current (DC) plating method.

Test boards of printed circuit board (PCB) fragments with BVHs and THs for filling plating are designed. The filling plating is conducted in a DC plating device, and the filling processes and influence factors on filling effect of BVHs and THs are investigated. Dimple depths, surface copper thickness, thermal shock and thermal cycle test are applied to characterize filling effect and reliability. In addition, to overcome thickness, increase of copper on board surface during filling plating of BVHs and THs, a simple process called pattern plating, is put forwarded; a four-layered PCB with surface copper thickness less than 12 μm is successfully produced.

The filling plating with the new copper electroplating formula is potential to replace the conventional filling process of BVHs and THs of PCB and, most importantly, the problem of thickness increase of copper on board surface after filling process is overcome if a pattern plating process is applied.

The dimple depth of BVHs and THs after filling plating is not small enough, though it meets the requirements, and the smallest diameter and largest depth of holes studied are 75 and 200 μm, respectively. Hence, the possibility for filling holes of much more small in diameter and large in depth with the plating formula should be further studied.

The paper introduces a new copper electroplating formula which achieves BVHs and THs filling at one process through a DC plating method. It overall reduces production processes and improved reliability of products resulting in production cost saving and production efficiency improvement.

The purpose of this paper is to study the effect of chromium content on the microstructure and corrosion resistance of Ni-Cr coating.

Ni-Cr coating was prepared by pulse current electrodeposition with trivalent chromium. On the basis of studying effect of electroplating parameters on composition and morphology, Ni-Cr alloy coatings with various chromium contents were obtained. The microstructure was characterized by scanning electron microscopy, X-ray diffractometer and transmission electron microscopy. Corrosion behavior was studied by potentiodynamic polarization and electrochemical impedance spectroscopy techniques.

Electrodeposited chromium was solidly dissolved in nickel and refined the grain of the coating. With the increase of Cr content, the corrosion resistance of Ni-Cr coating was enhanced, which is due to the formation of continuous nickel hydroxide and compact chromium oxide passive films.

Ni-Cr alloy coating without penetration crack was prepared in trivalent chromium electrolyte, and the mechanism of its excellent corrosion resistance was proposed.