Plating Film Research Articles

Interfacial microstructure and mechanical properties of joining electroless nickel plated quartz fibers reinforced silica composite to Invar

Vacuum brazing of electroless nickel plated quartz fibers reinforced silica composite (QFSC) to Invar alloy using Ag–Cu eutectic alloy at various temperatures (1073–1163 K) and times (5–35 min) has been investigated. The scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction examination of the joints showed that the junction between QFSC and Invar produced reaction products like Cu 3.8Ni, Cu (s, s), Ni (s, s) and Ag (s, s), with the structure of Invar/Cu 3.8Ni + Ni (s, s)/Ni (s, s) + Cu 3.8Ni + Ag (s, s) + Cu (s, s)/Cu (s, s) + Cu 3.8Ni + Ni (s, s) + QFSC. The shear strength of joint was effected by the changes of relative amount of Cu–Ni eutectic structure (Cu 3.8Ni + Ni (s, s)) and thickness of nickel plating film at different parameters. The shear strength of joint increased when there were proper amount of Cu–Ni eutectic structure and nickel plating film for reinforcement, and decreased while them were consumed excessively in interaction. The maximum shear strength of joint is 29 MPa, which was brazed at 1103 K for 15 min.

복합 착화제 첨가가 무전해 Ni-P 도금액의 특성에 미치는 영향

In this study, the effects of multi-complex agents addition on characteristics of electroless Ni plating solution are investigated. The species and the concentration of complexing agents are major factors to control the deposition rate, P concentration, and surface morphology of plating films. Adipic acid increases the deposition rate in regardless of single- or mutli-complex agent addition. However, lactic acid effectively increases the deposition rate in case of multi-addition as the complex agents with adipic or sodium succinate acid. In addition, sodium citric acid and malic acid show good stabilizing effects of plating solution and lowering the deposition rate, because they have high complexibility. Therefore, it is suggested that the development of Ni-P plating solution suitable for diverse usages can be carried out systematically using the database from this study.

Effects of Additives on Cu-MWCNT Composite Plating Films

The effects of plating bath additives on copper-multiwalled carbon nanotube (MWCNT) composite platings were studied. An acidified cupric sulfate electrolyte containing MWCNTs and polyacrylic acid as a dispersing agent was used as the base plating bath. Chloride ions , poly(ethylene glycol), bis(3-sulfopropyl)disulfide (SPS), and Janus green B (JGB) were examined as additives. The surface morphologies and cross-sectional microstructures of the electrodeposited films were investigated, and the MWCNT content of the films was determined. Furthermore, the electrical resistivity and field emission properties of the films were evaluated. The simultaneous addition of , SPS, and JGB to the base plating bath was effective for forming smooth Cu-MWCNT composite films with a high MWCNT content over a wider range of current densities. The optimal bath composition was 0.85 mol SPS + 2 ppm JGB +50 ppm Cl−. Cu-MWCNT composite films containing 0.15–0.33 mass % MWCNTs with smooth surface morphologies were formed in the current density range of . The electrical resistivity of the films was around , and they showed obvious field emission properties.

Copper-Filled Through-Hole Electrode of a ZnS Window Material for Sealing a Thermal Infrared Sensor

The through-hole electrode for the wafer level package (WLP) was formed with the aim of lowering the cost of infrared sensors. It has been difficult to plate a ZnS substrate for use as the window material of WLPs because of low adhesion. However, through-hole filling was successfully accomplished in this work by applying a newly developed method of direct nonelectrolyte plating. Concretely, a blast cleaning process was performed on a ZnS substrate of 1 mm thickness. Then, a through-hole with both sides tapered was formed with an aspect ratio of 7. A compound process of Cu substitution plating and Ni nonelectrolyte plating was applied to the through-hole, forming a uniform plating film with high adhesion in the hole. Finally, the through-hole was completely filled by Cu electroplating. A He leak test confirmed that the sample had high sealing properties, with a measured leak rate of 1.0 × 10-10 Pa·m3/sec or less. The results showed that a ZnS substrate can be used effectively for IR window material, making it possible to reduce the cost of infrared cameras.

Effect of Oxygen Plasma Treatment on Adhesion of Copper Plating Film to Polyimide Film for Flexible Printed Circuits

In flexible printed circuits (FPCs), polyimide (PI) resin, which has low dielectric constant, is used for the substrate, and copper, which has low resistance, is used for the wiring. In general, a surface modification technique is applied to the PI resins because the adhesion between PI and copper is poor. Oxygen plasma treatment is a modification technique that should improve adhesion. The treatment increases fine surface roughness and activates the PI surface by introducing functional groups. In this study, the effects of plasma treatment on the surface properties of PI film and on the adhesion of copper plating film to PI film were investigated for high-quality FPCs. In the RF-reactive ion etching (RF-RIE) plasma treatment, oxygen was used as the processing gas. It was at a flow rate of 30 sccm for 3∼20 minutes. The adhesive strength of the copper plating film to PI film was measured using a 90° peel tester. The oxygen plasma treatment improved the adhesion, and the adhesive strength of around 400 N/m is close to a practical level.

Study on the Composite Technology of Electro-Brush Plating and Arc Spraying

Zinc-alloy with low melting point can be easily sprayed directly on the production surface to fabricate a mould with high precision by arc spraying. But the zinc-alloy mould has the disadvantage of easy invalidation due to its relatively low hardness and poor anti-wear property. In this paper, the surface modification of zinc-alloy tooling by composite electro-brush plating was researched. The joining mechanism between the plating film and sprayed coating was investigated, and the law of quality control on the unification of rapid tooling and surface modification was revealed. A new modification technology possessing the advantage of economical and high quality surface relating to moulding was developed with independent intellectual property right.

The embrittlement mechanism and improvement of impact strength for lead-free solder joints in BGA packaging using electrolytic Ni/Au plating

Impact strength evaluation and fracture mechanism analysis in board level of Sn–3mass%Ag–0.5mass%Cu solder joints of ball grid arrays (BGA) using electrolytic Ni/Au plating were performed. The cause of impact strength degradation of BGA solder ball joints is the existence of low density defects, which contain organic materials, in the (Cu,Ni)6Sn5 intermetallic compound grain boundary formed in the solder joints. These organic materials are taken in by the nickel plating film at the time of nickel plating. To improve the impact strength of the Sn–3mass%Ag–0.5mass%Cu solder joint of the BGA, it is necessary to lower the concentration of these organic materials. The contamination prevention and nickel plating bath sanitization, solder mask material selection (to minimize nickel plating bath contamination) and higher current density of nickel plating are effective to keep a lower concentration of organic materials in nickel plating film.

Gold–Carbon Nanotube Composite Plating Film Deposited Using Non-Cyanide Bath

We developed a gold–carbon nanotube (Au–CNT) composite plating film by electrodeposition. An effective additive was added into a non-cyanide CNT plating solution, affording an environmentally friendly method for fabricating an Au–CNT composite plating film using a basic solvent. The fabricated Au–CNT composite film was harder than the Au film by 1.4 times and showed a low friction coefficient. Thus, the Au–CNT composite film could be considered as a promising material for next-generation electrical contact applications.

Assessing Aptitude of Plated Ni–W Film as Mold Materials for Borosilicate Glass

We propose the Ni–W plating film as a mold material for the hot embossing of borosilicate glass. The lifetime of a Ni–W plating mold is important from a practical perspective. However, there have been no previous reports on the life of a mold. Contact angle has been reported as a parameter for the comparative assessment of wettability. In this report, we identified the components of borosilicate glass reacted with a Ni–W film by elemental analysis together with a wettability test. In the wettability test, increasing temperature caused a decrease in of contact angle, which is caused by the chemical reaction at the center of glass. In the results of the elemental analysis of the Ni–W film in contact with glass, Zn, a constituent of the glass, was not detected in the noncontact zone, but was detected in the contact zone. There is no binary alloy phase diagram of W–Zn. It is considered that W does not form an alloy with Zn. Results from the reaction of Zn on Ni indicated an increase in the wettability of borosilicate glass for the Ni–W plating film.

Electroless plating of aluminum using diisobutyl aluminum hydride as liquid reducing agent in room-temperature ionic liquid

We investigated an electroless aluminum plating based on using AlCl 3–1-ethyl-3-methylimidazolium chloride (AlCl 3–EMIC) ionic liquid with diisobutyl aluminum hydride (DIBAH) as a liquid reducing agent. The plating film was analyzed by measurements of X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX) and glow discharge optical emission spectroscopy (GD-OES). Consequently, a thick aluminum plating film with high uniformity was prepared from AlCl 3–EMIC with DIBAH. No impurity phases were detected. Moreover, we discussed the reaction mechanism of the electroless aluminum plating.

MEMS-based carbon nanotube and carbon nanofiber Cu micro special electric contact

Two new electrical contact materials, carbon nanotube (CNT) and carbon nanofiber (CNF), Cu-matrix composite films are prepared by composite electroplating. The microstructure, morphology and physical performance of Cu–CNT/CNF composite films were analyzed by a scanning electron microscope, a Vickers hardness tester and a semiconductor parameter analyzer. The scanning electron microscope images showed that the CNTs/CNFs were dispersed uniformly and combined well in the Cu matrix. Furthermore, the Cu–CNT/CNF composite films show relatively good physical properties, for example the hardnesses of Cu/CNT and Cu/CNF composite films are 156 HV and 207 HV, about 13.9% and 51.1% higher than that of the pure copper plating film (137 HV); the resistivities of CNT/CNF composite plating films are 2.656 × 10−6 Ω cm and 1.815 × 10−6 Ω cm, lower than those of other Cu-matrix composites such as CuW, 4.35 × 10−6 Ω cm, and CuMo, 3.571 × 10−6 Ω cm. In addition, CNT and CNF Cu micro special electric contacts have been designed and successfully fabricated by MEMS technology. The arc-erosion behavior of Cu/CNT and Cu/CNF contacts has been examined on an electric arc-erosion apparatus. The test result shows that the arc-erosion losses of Cu/CNT and Cu/CNF contacts are 2.7 mg and 3.0 mg, 22.9% and 14.3% lower than that of pure Cu (3.5 mg) under the same condition.

Properites of Immersion Tin Plating Film Prepared by Spherical Gel Electrolyte Particle

not Available.

Preparation and characterization of sol–gel Al 2O 3/Ni–P composite coatings on carbon steel

Ceramic films have been applied to improve the resistance against high temperature oxidation of carbon steels. Alumina film was prepared on carbon steel surface by a dip coating technique. Electroless Ni–P plating film has been pre-deposited as an intermediate layer to improve the adherence of the film to carbon steel substrate. The oxidation kinetics of coated sample was investigated by measuring weight gain at 800 °C for 100 h. The surface and cross-section morphology of samples before and after oxidation were characterized by scanning electron microscopy (SEM). The composition and element distribution at the interface of the coated samples were analyzed by energy dispersive spectroscopy (EDS) and EMAX. The results show that the composite coating is uniform. The alumina coating adhesion strength to the substrate is up to 20 ± 2 N in scratch test because the alumina film presents interdiffusion of nickel and aluminum during heat treatment. The oxidation resistance test indicates higher oxidation resistance of as-coated carbon steel comparing to uncoated ones.

Basic Research on the Metallization of Aluminum Pads, Silicon Nitride and Polyimid by Electroless Nickel-Phosphorus Plating

The metallization of aluminum (Al), silicon nitride (SiN) and polyimide (PI) have been investigated by changing the activation method necessary to start electroless plating. The adhesion force between the substrate materials and the following electroless Ni–P plating film is investigated. A one-solution type activation method is too acidic for Al and a zincate process is necessary for metallization. The polyimide substrate showed enough adhesion force for tape peel test. The silicon nitride substrate is difficult to plate uniformly. To increase the adsorption of the Pd catalyst, a conditioning process is effective for the SiN substrate. For one-solution type activation, the zincate process is necessary for the Al substrate and the conditioning process is necessary for the SiN substrate. A two-solution type activation method is available for all substrates and three repetitions are necessary for the SiN substrate. The adhesion force between the plated film and substrates is quantified. The highest value was obtained for the Al substrate after the zincate process, and the lowest value was obtained for the SiN substrate after two-solution type activation. Sufficient adhesion force, over 600 kg/cm 2 , was obtained for all substrates with the two-solution type activation method. Therefore, the two-solution method shows high

ＤＩＢＡＨとＢｉＣｌ３を含むＡｌＣｌ３‐ＥＭＩＣ室温イオン液体を用いた無電解Ａｌめっき

We investigated electroless aluminum plating using AlCl3-1-ethyl-3-methylimidazolium chloride (AlCl3-EMIC) ionic liquid containing diisobutyl aluminum hydride (DIBAH) and BiCl3. The plating film was analyzed using X-ray diffraction and scanning electron microscopy. The aluminum films prepared with BiCl3 were smoother than those prepared without BiCl3. Furthermore, the plating bath stability was improved by addition of BiCl3.

Ｎｂナノ粒子を用いた反応性複合無電解Ｎｉ‐Ｐめっき膜の合金化

Composite plating improves functionalities of wear resistance, corrosion resistance, lubricity, etc. through co-deposition with suitable particles. For this study, reactive metallic particles were introduced intentionally as a dispersant. Heat treatment was used to form an alloy with a plated matrix. Composite plating films were formed using electroless Ni-P plating with Nb powder of two types as dispersants: nanopowder (ca. 300 nm diameter) and micropowder (ca. 50 μm diameter). The composite plating film was alloyed using heat treatment at 800°C for 1 hour under vacuum conditions. X-ray diffraction (XRD) analysis confirmed that the proportion of alloy to reactive composite film with nanopowder was much larger than that with micropowder. Results of X-ray photoelectron spectroscopy (XPS) analyses suggest that a selective Nb oxide was formed on the composite film surface when using Nb nanopowder. On the other hand, almost no Nb micropowder was changed to alloy or oxide in the composite films. Using nanopowder, much of the composite plating film formed reactive composite plating film alloy during heat treatment.

An Embrittlement Mechanism of Impact Fracture of Sn–Ag–Cu Solder Joints on BGA Using Electroplated Ni/Au Surface Finishes

The impact toughness evaluation and fracture mechanism analysis in board level of Sn-3 mass%Ag-0.5 mass%Cu solder joints of ball grid arrays (BGAs) using electrolysis Ni/Au plating were performed. The cause of impact toughness degradation of BGA solder ball joints is the segregation of impurities to the (Cu, Ni)6Sn5 intermetallic compound grain boundary formed in the solder joints. The impurities, consisting of Cl and organic matters, are taken in the Ni plating film at the time of Ni plating. The organic matter impurities come primarily from the solder mask of the BGA interposer substrates. To improve the impact toughness of the Sn-3 mass%Ag-0.5 mass%Cu solder joint of the BGA, it is necessary to lower the concentration of these impurities. This, in turn, places importance on solder mask material selection (to minimize Ni plating bath contamination) as well as contamination prevention and plating bath sanitization.

An electroless plating film of palladium on 304 stainless steel and its excellent corrosion resistance

An uniform palladium film on 304 stainless steel was obtained by electroless plating. Scanning electronic microscopy, X-ray photoelectron spectroscopy, weight loss tests and electrochemical measurements were used to character the properties of the film. The palladium plated stainless steel samples showed excellent corrosion resistance in strong reductive corrosion mediums. In boiling dilute sulfuric acid solutions and boiling acetic/formic acids, corrosion rates of palladium plated 304 stainless steel samples were 3 or 4 orders of magnitude lower than the original 304 stainless steel samples. In solutions with NaCl concentration less that 0.1%, the palladium plated samples also showed better corrosion resistance. The function of palladium film on stainless steel is to raise the electrode potential and promote passivation of the steel in strong corrosive environments.

ジンケート処理におけるアルミニウム合金表面のＸＰＳによる検討

It is well known that the adhesion strength of metal plating film on Al substrate should be remarkably improved by introducing double zincate treatment as a pretreatment process for metal plating on Al. At each step of alkaline etching, desmutting, the first zincate treatment, HNO3 dipping, and the second zincate treatment in the double zincate process, depth profiles and the chemical state of the surface elements were extensively measured by XPS. A set of surface structure models in the process was proposed to explain the improvement of the adhesion strength by double zincate treatment.By dipping the first zincate film in HNO3 solution, a granular zinc deposit of about 1 μm thickness, roughly deposited on Al passivation film at the first zincate treatment, was dissolved, and zinc nano-particles were believed to be concurrently formed in the Al passivation film of about 3nm thickness. In the second zincate treatment the nano-particles should be exposed to the second zincate solution to act as nuclei for formation of a highly uniform and thin zinc film. The zinc particles were so close to the metallic Al substrate, that Dipolar coupling such as Alδ+…Oδ&minus…Znδ+ would act to improve the adhesion strength of double zincate film on Al substrate.

めっき膜に生じるクラック検出のための電気化学インピーダンス解析法

Cracks are often formed in nickel-alloy plating by high tensile stress. Therefore, an accurate crack detection method is required. The method for detecting cracks in Ni-W plating film with electrochemical impedance spectroscopy (EIS) was studied in the present paper. The impedance of Ni-W plating film without cracks in 1M sulfuric acid solution shows two capacitive loops. The impedance of Ni-W plating film with cracks in 1M sulfuric acid solution shows also two capacitive loops. The capacitive loops of impedance of Ni-W plating film without crack were smaller than those of Ni-W plating film with cracks. Curve-fitting was performed for the impedance spectra by assuming equivalent circuits, and the calculated impedance spectra were in agreement with the experimental results. In those results, the charge transfer resistance and double-layer capacitance varied with the area of cracks in Ni-W plating film. It can be concluded that impedance analysis can detect cracks in Ni-W plating film.