Nickel Electroplating Research Articles

NiO Development on FeCrAl Substrate for Catalytic Converter Using Ultrasonic and Nickel Electroplating Methods

The irregular surface roughness morphology due to ultrasonic method was used approach for increasing the high surface area of substrate and catalyst. The purpose of this paper is to show the ultrasonic and nickel electroplating methods for NiO automotive catalyst development on FeCrAl substrate. The process began with pretreatment of FeCrAl using SiC and/or Al2O3 solution agitating by ultrasonic and followed with nickel electroplating. The oxidation test was conducted for developing the NiO. The physical morphology structure of the presence NiO on the FeCrAl substrate was analyzed using scanning electron microscope (SEM) in combination with energy dispersive X-ray spectroscopy (EDS). The cross sectional observation show the NiO catalyst completely existed on the FeCrAl. The ultrasonic method increases the irregular surface roughness morphology on FeCrAl substrate that influenced the homogeneous and stability of nickel electroplating and NiO surface area development.

Design of experiments for statistical modeling and multi-response optimization of nickel electroplating process

The central composite experimental design and response surface methodology have been employed for statistical modeling and analysis of the results dealing with nickel electroplating process. The empirical models developed in terms of design variables (current density J (A/dm 2), temperature T (°C) and pH) have been found statistically adequate to describe the process responses, i.e. cathode efficiency Y (%), coating thickness U (μm), brightness V (%) and hardness W (HV). The graphical representations consisted of 2D contour plots and 3D surface plots have been used for exploring and analysis of response surfaces in order to identify the main, quadratic and interaction effects. The multi-response optimization of nickel electroplating process has been carried out by means of desirability function approach. To this end, a genetic algorithm has been used for mathematical optimization of the multi-response problem. The optimization algorithm has conducted to a set of equivalent solutions named Pareto optimal set. The confirmation runs have been employed in order to make a decision about the optimal solution approved by experiment. Thus, the optimum conditions of nickel electroplating has been defined in this work as J* = 5.35 (A/dm 2), T* = 33.44 (°C) and pH* = 6.22 and respectively the responses confirmed by experiment were Y = 79.12 ± 0.18 (%), U = 52.77 ± 0.48 (μm), V = 26.12 ± 0.45 (%) and W = 371.6 ± 1.77 (HV). In such conditions the quality of nickel electroplating deposit was the best one in accordance with experimental results.

Autothermal reforming of ethanol in a Pd–Ag/Ni composite membrane reactor

The main objective of this project is to study the hydrogen production reaction from oxidative steam reforming of bio-ethanol in the pertinent characteristics of a palladium–silver alloy membrane reactor. The enhancements of hydrogen permeation and of H 2/N 2 permselectivity were studied in a Ni–Pd–Ag ternary alloy membrane, which was fabricated by successive electroless plating of palladium and silver on stainless steel (PSS) supports modified with nickel electroplating. XRD, SEM, and EDS were used to characterize the surface morphology of the membranes. Ethanol–water mixture ( n water/ n ethanol = 1 or 3) and oxygen ( n oxygen/ n ethanol = 0.2 or 0.7) were fed concurrently into the membrane reactor packed with Zn–Cu commercial catalyst (MDC-3). The reaction temperatures were set at temperatures of 593–723 K and pressures of 3–10 atm. The amount of oxygen added in the feed has a significant effect on the steam reforming reaction of ethanol. At high pressures, autothermal reaction of ethanol with no need for external heating to the composite membrane reactor to produce high purity hydrogen was easily processed.

Removal of Ni(II) from electroplating rinse waters using cation-exchange resins: batch and column studies

The adsorption of Ni (II) from nickel electro plating rinse water has been attempted. Indion 225 and Dueolite C 20 cation-exchange resins through batch and column mode for the recovery of Ni (II), which showed a remarkable increase in sorption capacity. On the basis of isotherm analysis, more efficient adsorbent is chosen for column mode adsorption studies. The continuous-flow study was to investigate the effect of various process variables, like bed height, hydraulic loading rate on breakthrough and adsorption capacity. An attempt has also been made the data using Bohart?Adams approach to design the adsorption system.

A sub-micron metallic electrothermal gripper

We report the design, fabrication, and characterization of a multiple bent beam, sub-micron metallic electrothermal gripper. A bottom electroplating mold for electrodes was patterned using electron beam lithography in an SU-8, followed by nickel electroplating. A top electroplating mold for a sub-micron metallic gripper with high aspect ratio bent beams (thickness of 1 μm, width of 350 nm) was prepared using electron beam lithography in a polymethyl methacrylate (PMMA), followed by nickel electroplating and dry release of the top and bottom molds. The sub-micron gripper was characterized using a nanomanipulator system installed in a dual column scanning electron microscopy/focused ion beam system. The ability of the jaw to close up to 1.39 μm displacement with high precision and reliability has been reproducibly observed at an applied current of 28 mA, corresponding to the maximum power consumption of 11.2 mW. Finite element modeling displacement results performed using ANSYS for effective bent beam widths of 370 nm showed a good agreement with the measured displacement results. The sub-micron gripper demonstrated herein will enable the reproducible manipulations with nano-scale resolution displacement and could provide an effective means of interface between nano-scale objects and the micro/macro scale robotic systems.

Fabrication of a high aspect ratio thick silicon wafer mold and electroplating using flipchip bonding for MEMS applications

We have developed a microfabrication process for high aspect ratio thick silicon wafer molds and electroplating using flipchip bonding with THB 151N negative photoresist (JSR micro). This fabrication technique includes large area and high thickness silicon wafer mold electroplating. The process consists of silicon deep reactive ion etching (RIE) of the silicon wafer mold, photoresist bonding between the silicon mold and the substrate, nickel electroplating and a silicon removal process. High thickness silicon wafer molds were made by deep RIE and flipchip bonding. In addition, nickel electroplating was developed. Dry film resist (ORDYL MP112, TOK) and thick negative-tone photoresist (THB 151N, JSR micro) were used as bonding materials. In order to measure the bonding strength, the surface energy was calculated using a blade test. The surface energy of the bonding wafers was found to be 0.36–25.49 J m−2 at 60–180 °C for the dry film resist and 0.4–1.9 J m−2 for THB 151N in the same temperature range. Even though ORDYL MP112 has a better value of surface energy than THB 151N, it has a critical disadvantage when it comes to removing residue after electroplating. The proposed process can be applied to high aspect ratio MEMS structures, such as air gap inductors or vertical MEMS probe tips.

Studies on influence of zinc immersion and fluoride on nickel electroplating on magnesium alloy AZ91D

The effect of zinc immersion and the role of fluoride in nickel plating bath were mainly investigated in nickel electroplating on magnesium alloy AZ91D. The state of zinc immersion, the composition of zinc film and the role of fluoride in nickel plating bath were explored from the curves of open circuit potential (OCP) and potentiodynamic polarization, the images of scanning electron microscopy (SEM) and the patterns of energy dispersive X-ray (EDX). Results show that the optimum zinc film mixing small amount of Mg(OH) 2 and MgF 2 is obtained by zinc immersion for 30–90 s. The corrosion potential of magnesium alloy substrate attached zinc film will be increased in nickel plating bath and the quantity of MgF 2 sandwiched between magnesium alloy substrate and nickel coating will be reduced, which contributed to produce nickel coating with good performance. Fluoride in nickel plating bath serves as an activator of nickel anodic dissolution and corrosion inhibitor of magnesium alloy substrate. 1.0–1.5 mol dm −3 of F − is the optimum concentration range for dissolving nickel anode and protecting magnesium alloy substrate from over-corrosion in nickel plating bath. The nickel coating with good adhesion and high corrosion resistance on magnesium alloy AZ91D is obtained by the developed process of nickel electroplating. This nickel layer can be used as the rendering coating for further plating on magnesium alloys.

Development of elastomeric lab-on-a-chip devices through Proton Beam Writing (PBW) based fabrication strategies

In recent years, one of the most exciting developments in fluidic device applications is the rapid evolution of miniaturized micro- and nanofluidic systems, the so called “lab-on-a-chip” devices. These devices integrate laboratory functions into a single chip, and are capable of various biochemical analysis and synthesis, such as sample injection and preparation, single cell/molecule observation, bioparticle sequencing and sorting etc. The evolvement of lab-on-a-chip concept implies the use of novel fabrication techniques for the construction of versatile analytical components in a fast and reproducible manner. Endowed with unique three-dimensional fabrication abilities, Proton Beam Writing (PBW) [1], which is capable of producing nanometer scaled fluidic structures with smooth and straight side wall features, has a great potential to develop all sorts of polymer fluidic devices. In this paper, we describe the batch fabrication of Poly-dimethysiloxane (PDMS) elastomeric lab-on-a-chip devices utilizing PBW technique. A series of fabrication processes, involving PBW, nickel electroplating, soft lithography, polymer dynamic coating and hydrophilic treating, were modified and adopted in our work. Subsequent characterization of individual categories of channel devices was carried out for specific fluidic studies. Respective experimental procedures are presented and results are explained. The channel devices demonstrated good fluidic performance and functionality, suggesting their further application in more complex biological investigations, and the versatility of PBW in lab-on-a-chip development.

Low-ammonia, high-speed palladium—nickel electroplating process for connector applications: One-year industrial practice results for Pallamet 600 support claims regarding the process' suitability as a hard gold replacement

The Pallamet 600 process presents the advantages of both conventional ammoniacal and ammonia-free processes. The on-line ammonia odor in a production environment is dramatically reduced due to the extremely low free ammonia in the electrolyte. In addition, Pallamet 600 does not require any addition of ammonia for pH adjustment during use. The beneficial characteristics of the plating process and the Pd−Ni deposit of the conventional ammonia-based processes are retained with Pallamet 600. Production trials have shown that the Pallamet 600 process is suitable for various reel-to-reel selective plating techniques, and the plating bath is chemically stable, in spite of the low ammonia content. The quality of the Pd−Ni deposits produced by Pallamet 600 has been well accepted by end users as a viable hard gold replacement at a substantially lower cost.

The influence of the nature of background anions on the buffer capacity of glycine-containing electrolytes for nickel electroplating

The buffer properties of acetate, sulfate, and chloride glycine-containing electrolytes for nickel electroplating were studied. Various forms of the amino acid and background anions were shown to act in solution as two buffer systems related by competitive complex formation. The buffer capacity of a solution was then the result of the joint action of these systems. The contribution of each of them was determined by its absolute concentration in solution on the one hand and changes in this concentration caused by the addition of H+ or OH− ions on the other.

Densely-Packed Microbowl Array with Balanced Dielectrophoretic Forces for Single-Cell Microarray

AbstractIn this paper, we demonstrate a perfectly-ordered microbowl array with balanced dielectrophoresis (DEP) for a high-throughput single-cell analysis. In order to fabricate well-ordered microbowl array in a large area, we utilized three-dimensional diffuser lithography for photoresist mold and nickel electroplating technique for final microbowl structures on a silicon substrate. Single microbowl has six sharp apexes surrounding the microbowl perimeter. Each microbowl has a diameter of 10 μm, and a height of 9 μm, which can be controllable by patterns on mask and lithography conditions. To investigate feasibility for application to the microbowl array as a single-cell microarray, we used latex beads of 6.4 μm in an average diameter to be captured by dielectrophoretic force. The nickel microbowl array densely packed with a hexagonal geometry played as a bottom electrode, and an ITO-coated glass covered the nickel microbowl array as a top electrode while keeping a uniform gap between two electrodes. After injecting solution containing latex beads through the gap, we applied an AC signal (2 VPP, 1 MHz) between two electrodes to induce high electric field near the sharp apexes of the single microbowl. A negative DEP trap is formed at the center of the single microbowl with balanced DEP force from the six apexes. The experimental result shows that injected latex beads had been successfully and uniformly aligned and trapped at the microbowl array sustained by negative DEP.

Microinjection molded disposable microfluidic lab-on-a-chip for efficient detection of agglutination

Previous diagnosing methods based on agglutination have a limitation in view of emergency and point-of-care diagnoses due to the requirement of large scale equipments and much agglutination time. In this paper, we propose a low cost microfluidic lab-on-a-chip for more efficient detection of agglutination. In the present lab-on-a-chip, two inlet microwells, flow guiding microchannels, chaotic micromixer and reaction microwell are fully integrated. Mold inserts for the lab-on-a-chip were manufactured by UV photolithography and nickel electroplating process. The complete lab-on-a-chip was realized by the microinjection molding of cyclic olefin copolymer and the subsequent thermal bonding. The improved serpentine laminating micromixer, developed by our group, integrated in the lab-on-a-chip showed the high-level of chaotic mixing, thereby enabling us to get a reliable mixing of sample and reagent. The performance of the fabricated lab-on-a-chip was demonstrated by agglutination experiments with simulated bloods of 10 μl and simulated sera of 10 μl. The results of agglutination inside the reaction microwell were clearly read by means of the level of light transmission. The present microfluidic lab-on-a-chip could be widely applied to various clinical diagnostics based on agglutination tests.

An Improved Process for Fabricating Microlens Array With High Fill Factor and Controllable Configuration

An improved process has been developed for the efficient fabrication of a microlens array with high fill factor and controllable configuration. The microlens mold for patterning transformation was fabricated by using the processes of glass wet etching, nickel electroplating, photoresist spin coating, and encapsulated air heating. The convex microlens shape resulted from the photoresist compressed by the thermal expansion of sealed air to form a semispherical shell. By adjusting the heating temperature and the sealed air volume, the curvature and size of the shell are controllable. In addition, the microlens mold or plano-convex micromirror can be fabricated by depositing a metal film on the surface profile of swelled photoresist. An analytical model was established to predict the surface profile of a single microlens and was experimentally verified. A typical microlens mold made from nickel with different fill factors and various configurations was also fabricated and characterized. The polysiloxine microlens array was also fabricated by mold pressuring, and its optical properties were measured to identify the focusing capability. Experimental results reveal that various configurations of microlens array could be formed, such as semielliptical and M-character, by defining the pitch sizes of via holes. High fill factors approaching 100% can also be achieved. The fabrication provides an effective way to manufacture a microlens mold to serve as the master element for replication.

Post‐CMOS micromachined nickel tunable‐capacitors with a large tuning‐range under low actuating voltage

AbstractA novel metal micromachining technique is presented, with which both area‐tuning and gap‐tuning variable capacitors are designed and fabricated. Mainly comprising nickel electroplating and gaseous isotropic etching, the developed micromachining technique can be processed in low resistivity silicon substrate under low temperature (max. 120°C). Thus, the micromachined tunable‐capacitors can be on‐chip integrated into RF (radio‐frequency) ICs by means of post‐CMOS compatibly process. The fabricated tunable‐capacitors are measured, generally resulting in a larger tuning‐range than 200% (namely 3:1) under 4‐V actuation voltage. The Q‐factor for the area‐tuning capacitor (C0 = 0.28 pF) is measured as 169 at 1 GHz and 46 at 2 GHz, respectively, while the gap‐tuning style capacitor (C0 = 0.37 pF) is with the Q measured as 87 at 1 GHz and 35 at 2 GHz. With the successful application in the tunable‐capacitors, the developed post‐CMOS compatible metal micromachining techniques are promising for high‐performance on‐chip RF/microwave passives. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2469–2472, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23645

Electroplating of nickel from acetate based bath – Hull Cell studies

Electroplating of nickel onto steel substrates from an electroplating bath containing nickel acetate, nickel chloride, boric acid and acetic acid has been investigated under different levels of operating conditions such as bath composition, current density and temperature. A detailed study has been made on the influence of these variables by measuring cathodic current efficiency and throwing power for various baths. Deposition parameters have been optimised using Hull Cell experiments. From potentiodynamic polarisation studies on Ni deposits it was revealed that Ecorr moved towards the more negative direction. It is inferred from this fact that there is cathodic control of the corrosion reaction. The Rt value increases with increasing deposit thickness and the corresponding Cdl value is decreased.

나노 임프린트 리소그래피법에 의한 나노미터급 원기둥 패턴을 갖는 도광판의 제작 공정 개발

PMMA light guiding plate with nano pattern was fabricated by nano imprint lithography method. A silicon mold for electroplating of nickel was fabricated by conventional photolithography process. A nickel stamp for nano imprint lithography was fabricated by electroplating process using silicon mold. The nano imprint lithography was performed on PMMA plate at <TEX>$140^{\circ}C$</TEX> under pressure of 20kN. The nano pattern on PMMA plate was investigated using FE-SEM. It is shown that the patterns were well transferred for several steps and the nano imprint lithography method could be applied for fabricating patterns of light guiding plate.

Replication Quality of Flow-Through Microfilters in Microfluidic Lab-on-a-Chip for Blood Typing by Microinjection Molding

In the present study, replication of flow-through microfilters in the newly developed microfluidic lab-on-a-chip for blood typing by microinjection molding process was experimentally investigated. As a precise replication of the microfilters was required in order to effectively filter out agglutinated red blood cells, the effects of important processing conditions on the replication of the flow-through microfilters were investigated. By using a mold insert fabricated by a nickel electroplating process and a newly designed mold base, microinjection molding experiments were carried out. A three-dimensional solid model reconstruction method was proposed with the help of specific features characterizing the geometry of microfilters, and accordingly, the feature values of the replicated microfilters were measured by a noncontact optical measurement system. So reconstructed solid modeling result was then used to investigate the effects of various processing conditions, such as a flow rate, a mold temperature, and a packing pressure. Amongst the processing conditions investigated in the present study, the flow rate was found to be the most important one.

A MEMS probe card with 2D dense-arrayed ‘hoe’-shaped metal tips

In this paper, we present a novel MEMS probe card with densely area-arrayed microprobes for the wafer-level test of advanced ICs. In a 4 inch silicon wafer, a total of about 110 000 probe tips can be simultaneously fabricated, with a two-dimensional tip pitch of 240 µm × 160 µm. The ‘hoe-shaped’ microprobe structure is composed of one or two planar arms and an up-tilted tip, both of which are high-yield fabricated with metal micromachining techniques including low-stress nickel electroplating. With micromachined cavities, the silicon wafer serves as moulds for the up-tilted metal probes. Then, the microprobes are finally flip-chip packaged to a ceramic board for further connection to automatic testing equipment (ATE). After the probe structures are formed, the silicon wafer is removed completely by using TMAH wet etching, while the probes are freed by silicon laterally etching. The measured spring constants for all the three types of probes agree well with the designed values. As both mechanical anchors and electrical interconnections, the Sn–Ag solder-bumps feature satisfactory properties. The tested contact resistance values for three different thin-film pads on dies under test are always below 0.8 Ω, while the current leakage between two adjacent probes is only about 150 pA under 3.3 V.

Fabrication of two types of micro ion sources for a micro time-of-flight mass spectrometer

This paper reports the fabrication of two types of micro ion sources for a micro time-of-flight mass spectrometer (TOFMS). The TOFMS is an analyzer that serves for the establishment of molecular weight by using the difference in the flight time of ions according to their mass-to-charge values. The micro TOFMS consists of a glass substrate with several nickel electrodes and a silicon substrate with an ion source. We have fabricated two types of ion sources using a hot filament and field emitters with a carbon nanoparticle structure. The overall size of the assembled device is 10 × 10 × 1 mm3. The hot filament is fabricated through the nickel electroplating process and some lithography processes. The carbon nanoparticle layer is grown by hot-filament chemical vapor deposition (HFCVD). The carbon nanoparticle field emitter has the triode structure with which we can control the emission current at low voltage. The maximum emission current of the hot-filament ion source is 0.28 μA. The emission current of the field emission ion source can be controlled from 0 to 18.5 μA when the gate voltage varies from 0 to 175 V.

Fabrication of Dicing-Free Vertical-Structured High-Power GaN-Based Light-Emitting Diodes With Selective Nickel Electroplating and Patterned Laser Liftoff Techniques

Through the use of selective nickel (Ni) electroplating, patterned laser liftoff technique, and surface roughing of the top n-GaN epilayer, a novel process for the fabrication of vertical-structured metal-substrate GaN-based light-emitting diodes (VM-LEDs) to avoid difficulties in Ni substrate dicing and improve device yield was proposed and demonstrated. In conjunction with a sidewall passivation with SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and keeping the size of epilayer smaller than that of Ni island, a considerable improvement in yield and device performance were shown. As compared to conventional lateral-structured GaN-based LEDs, VM-LEDs show an increase in light output power about 174% at 350 mA with a significant decrease in forward voltage from 3.5 to 3.17 V