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Article
Publication date: 1 February 2013

Xin Luo, Wenhui Du, Xiuzhen Lu, Toshikazu Yamaguchi, Gavin Jackson, Li lei Ye and Johan Liu

The composition and thickness of surface oxide of solder particles is extremely important to the quality of interconnect and reliability of packaged system. The purpose of…

Abstract

Purpose

The composition and thickness of surface oxide of solder particles is extremely important to the quality of interconnect and reliability of packaged system. The purpose of this paper is to develop an observable measurement to research the issue.

Design/methodology/approach

AES (Auger electron spectroscopy), XPS (X‐ray photoelectron spectroscopy), TEM (transmission electron microscopy) and STEM (scanning transmission electron microscopy) were employed to examine the oxide layer on microscale solder powders. Conventional techniques and FIB (Focus Ion Beam) were employed for the TEM sample preparation. High angle annular dark field (HAADF) pattern was applied to distinguish the oxide layer and the solder matrix by the contrast of average atomic number. The results were confirmed by AES and XPS measurement.

Findings

The solder powders were exposed to air (70% relative humidity) at 150°C for 0, 120 and 240 h for the accelerated growth of oxide. The surface oxide thickness was 6 nm and 50 nm measured by TEM for 0 h and 120 h samples, respectively. It was found that the increase in surface oxide thickness of solder particles is proportional to the rooting of time. The elemental distribution along the oxide was quantified by line scanning using STEM and the atomic ratio of Sn to O in the oxide layer nearer to the outer, the middle, and the inner (adjacent to the solder matrix) was found to be 1:2, 2:3 and 1:1, respectively. The result was validated using XPS which gave Sn to O ratio of 1:2 at 5 nm depth of surface oxide.

Originality/value

This is the first time FIB technology has been used to prepare TEM specimens for solder particles and TEM pictures shown of their surface oxide layer. Though requiring more care in sample preparation, the measurements by TEM and STEM are believed to be more direct and precise.

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Article
Publication date: 17 March 2012

Zhiping Zhu, Hui Zhang, Linlin Jing, Shuhua Xiong and Zhenghui Tan

The purpose of this paper is to research the morphologies of the oxide films formed on the internal surfaces of water wall tubes in a 600 MW furnace at 300° while using…

Abstract

Purpose

The purpose of this paper is to research the morphologies of the oxide films formed on the internal surfaces of water wall tubes in a 600 MW furnace at 300° while using CPT, CT, AVT(R) and AVT(O) water chemistry. In these water chemistry conditions, a layer of oxide film spontaneously forms in the furnace wall which could prevent corrosions in boiler water directly contact with the inner tube and reduce the probability of tube perforation.

Design/methodology/approach

The different morphologies, specific functions and distribution in the oxide film were identified by electrochemical workstation, XRD, SEM and EDAX.

Findings

It is concluded that metal surface was rugged and had deep corrosion in CPT. Ions penetrated into the oxides of large particles with gaps and intergranular corrosion occurred in CT conditions. In AVT(R), the oxide film uniformly covered on the metal surface played a protective role, but could be easily washed away by solution. The oxide film formed in AVT(O) was similar to AVT(R), but the difference is that large solid particles of Fe2O3 cover the outermost oxide film, which prevents the oxide film from being taken away by the flowing solution. In consequence, the degree of corrosion sustained by the tube walls is lowest in the case of AVT(O).

Originality/value

The results can provide reference for reducing the high temperature corrosion of metal in the actual operation.

Details

Anti-Corrosion Methods and Materials, vol. 59 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 1 April 1987

H. Akahoshi, K. Kogawa, Y. Suzuki and M. Wajima

A new treatment method for the copper innerlayers of polyimide multilayer printed wiring boards has been developed. Conventional oxide coatings experience acid penetration…

Abstract

A new treatment method for the copper innerlayers of polyimide multilayer printed wiring boards has been developed. Conventional oxide coatings experience acid penetration through the bonding interface during through‐hole plating pretreatment. This problem was eliminated by substitution of metallic copper for the surface oxide. Promotion of the copper innerlayer adhesion to the prepreg by the oxide coating was based upon a mechanical interlocking effect caused by the minute roughness of the oxide crystals. Reduction treatment of the surface oxide layer was found to give a metallic copper surface with no changes in its morphology. Adhesion strength of polyimide prepregs to copper foils after the reduction treatment was equivalent to that of the original brown oxide coating. Acid resistance was enhanced by elimination of the oxide layer from the bonding interface. The reduction treatment, combined with the conventional oxide coating technique, can realise high density multilayer printed wiring boards with greater reliability and performance.

Details

Circuit World, vol. 14 no. 1
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 1 April 1987

M. Bayes, K. Chiba and Y. Kurokawa

The key to the production of high quality multilayer PWBs lies in a clear understanding of the many interactions between the chemical and mechanical processing involved…

Abstract

The key to the production of high quality multilayer PWBs lies in a clear understanding of the many interactions between the chemical and mechanical processing involved. This describes some of these interactions, namely those between oxide treatment, lamination and drilling and the subsequent chemical processing steps, up to, and including, copper electroplating. Choice of oxide treatment has consequences that are not limited to the lamination and drilling operations. Process problems, such as ‘pink ring (haloing)’ are discussed in the context of their sensitivity to particular stages in the manufacturing process.

Details

Circuit World, vol. 14 no. 1
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 1 January 2006

Gary Brist and Don Cullen

To examine the impact of oxide and oxide alternative processes on signal loss in commercial RF applications.

Abstract

Purpose

To examine the impact of oxide and oxide alternative processes on signal loss in commercial RF applications.

Design/methodology/approach

Stripline conductors were formed using traditional oxide, oxide dissolution/reduction, and oxide alternative processes. Conductor geometry was measured and surface topography was characterized. Effective dielectric constants and characteristic impedance for each system was determined. Finally, line loss for each treatment and rework condition was charted to nearly 20 GHz. Electrical measurements were performed by taking S‐parameter measurements through 20 GHz using an agilent vector network analyzer (VNA).

Findings

The methods employed were sufficient to statistically characterize the increased loss associated with thick oxides and high‐microetch oxide alternatives. Lower etch oxide alternatives yielded benefits for signal integrity. Of importance, rework procedures gave unacceptable increases in line loss. Overall, however, the loss due to innerlayer bonding processes was not of sufficient magnitude to elevate oxides as a primary contributor to conductor loss. For the relative simple, high production system employing epoxy substrate, oxide loss was found to be far less than substrate effects, imaging quality, and foil treatment.

Originality/value

Electrical engineers and printed circuit board (PCB) designers strive to focus their efforts on improving the PCB processes leading to maximum conductor loss in the electronic system. This work shows that oxide treatments are not a primary factor in affecting loss. Significant improvements in signal integrity may be achieved, however, with the use of low‐etch oxide alternatives and with restrictions on oxide rework. In addition, this paper allowed for new interpretations of VNA data for better modeling of PCB system data using non‐classical analysis.

Details

Circuit World, vol. 32 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

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Article
Publication date: 20 January 2012

Shital Patil and Vijaya Puri

The purpose of this paper is to study properties of magnesium oxide and mixed magnesium oxide‐bismuth oxide thick films for application in tuned devices.

Abstract

Purpose

The purpose of this paper is to study properties of magnesium oxide and mixed magnesium oxide‐bismuth oxide thick films for application in tuned devices.

Design/methodology/approach

The effect of magnesium oxide and mixed magnesium oxide‐bismuth oxide thick films overlay of different thickness on Ag thick film microstrip rectangular patch antenna was investigated in the X band (8‐12 GHz). Using Ag thick film microstrip rectangular patch antenna the thick and mixed thick films was characterized by microwave properties such as resonance frequency, amplitude, bandwidth, quality factor and input impedance. Using the resonance frequency the permittivity of magnesium oxide and mixed magnesium oxide‐bismuth oxide thick films was measured.

Findings

Cubic structure of single magnesium oxide and monoclinic structure of bismuth oxide was present in mixed thick film. Also the morphology of single thick films was maintained in mixed thick film of magnesium oxide‐bismuth oxide. Due to overlay magnesium oxide and magnesium oxide‐bismuth oxide mixed thick films, change in resonance frequency shifts towards high frequency end was observed. Dielectric constant of magnesium oxide and mixed magnesium oxide‐bismuth oxide thick film calculated from resonance frequency decreased with increase in thickness.

Originality/value

The microwave properties using Ag thick film microstrip patch antenna due to overlay of magnesium oxide and mixed magnesium oxide‐bismuth oxide thick films have been reported for the first time. Thickness of overlay dependent tuning of the antenna has been achieved.

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Article
Publication date: 11 October 2019

Jia-Bo Zhang, Yang Yang, Xiao-Hui Zhang, Jia-Liang Guan, Li-Yan Zheng and Guang Li

The purpose of this study is to investigate the characteristic and function of oxide film formed on grinding wheel in electrolytic in-process dressing (ELID) precision…

Abstract

Purpose

The purpose of this study is to investigate the characteristic and function of oxide film formed on grinding wheel in electrolytic in-process dressing (ELID) precision grinding and improve the quality of ELID grinding.

Design/methodology/approach

Dynamic film forming experiments were carried out with a simulation device close to the actual processing conditions. Then, the ELID grinding experiments of bearing rings were performed using grinding wheels with good film forming effect. The experiment was designed by quadratic regression general rotation combination method. The influence of grinding depth, electrolytic voltage, duty cycle and grinding wheel linear speed on grinding effect is analyzed.

Findings

A mathematical model for the formation rate of oxide film was established. The experiments show that the composition of grinding wheel and grinding fluid, as well as the electrical parameters, influence the film forming effect. Thus, the oxide film plays an important role in ELID grinding.

Originality/value

This study provides a reference for the design and selection of grinding wheel and grinding fluid and the setting of process parameters in ELID grinding.

Details

Industrial Lubrication and Tribology, vol. 72 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 3 February 2021

Abdul Rehman, Mohammad Hassan Shirani Bidabadi, Liang Yang, Zheng Yu, Chen Hao, Chi Zhang and Zhigang Yang

This study aims to optimise the effect of pre-oxidation on hot corrosion behaviour of Tribaloy T-900 at 900 °C in mixed Na2SO4 and K2SO4.

Abstract

Purpose

This study aims to optimise the effect of pre-oxidation on hot corrosion behaviour of Tribaloy T-900 at 900 °C in mixed Na2SO4 and K2SO4.

Design/methodology/approach

Prior to hot corrosion experiment, pre-oxidation treatments were carried in ambient air at 900 °C for 1, 5 and 10 h, respectively. The hot corrosion experiments were performed in a box type furnace at 900 °C. Both surfaces of specimens were brushed with saturated salt solution of 75 wt.% Na2SO4 + 25 wt.% K2SO4. After brushing, the salt-coated specimens were placed in electric stove to ensure drying of salt. After drying, presence of 3 mg/cm2 salt on specimen’s surface was ensured through weighting.

Findings

The 1-h pre-oxidation treatment prior to hot corrosion showed superior hot corrosion resistance against molten salt attack. An optimum pre-oxidation time of 1 h helped timely formation of protective Cr2O3 layer and inhibited the formation of less stable and porous surface oxides of Ni and Mo during hot corrosion.

Originality/value

Pre-oxidation effect on hot corrosion behaviour of refractory metal (such as Mo in investigated alloy) containing alloy has never been reported previously. Refractory metals oxide (e.g. MoO3) could transform the corrosion phenomena to catastrophic failure through acidic fluxing.

Details

Anti-Corrosion Methods and Materials, vol. 68 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 9 April 2021

Hongda Deng, Yongliang Liu, Zhen He, Xiantao Gou, Yefan Sheng, Long Chen and Jianbing Ren

The purpose of this paper is to investigate and explain thermal oxide effect on electrochemical corrosion resistance anodized stainless steel (SS).

Abstract

Purpose

The purpose of this paper is to investigate and explain thermal oxide effect on electrochemical corrosion resistance anodized stainless steel (SS).

Design/methodology/approach

Electrochemical corrosion resistance of thermal oxides produced on anodized 304 SS in air at 350°C, 550°C, 750°C and 950°C in 3.5 wt.% NaCl solution have been investigated by dynamic potential polarization, EIS and double-loop dynamic polarization. Anodized 304 SS were obtained by anodization at the constant density of 1.4 mA.cm-2 in the solution containing 28.0 g.L-1H3PO4, 20.0 g.L-1C6H8O7, 200.0 g.L-1H2O2 at 70°C for 50 min. SEM and EDS had been also used to characterize the thermal oxides and passive oxide.

Findings

Interestingly, anodized 304SS with thermal oxide produced at 350°C displayed more electrochemical corrosion and pitting resistance than anodized 304 SS only with passive oxide, as related to the formation of oxide film with higher chromium to iron ratio. Whereas, anodized 304SS with thermal oxide formed at 950°C shows the worse electrochemical corrosion and pitting resistance among those formed at the high temperatures due to thermal oxide with least compact.

Originality/value

When thermally oxidized in the range of 350°C–950°C, electrochemical corrosion and pitting corrosion resistance of anodized 304 SS decrease with the increase of temperature due to less compactness, more defects of thermal oxide.

Details

Anti-Corrosion Methods and Materials, vol. 68 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 4 May 2020

Anh Thi Le and Swee-Yong Pung

This paper aims to investigate the reusability of metal/metal oxide-coupled ZnO nanorods (ZnO NRs) to degrade rhodamine B (RhB).

Abstract

Purpose

This paper aims to investigate the reusability of metal/metal oxide-coupled ZnO nanorods (ZnO NRs) to degrade rhodamine B (RhB).

Design/methodology/approach

ZnO NRs particles were synthesized by precipitation method and used to remove various types of metal ions such as Cu2+, Ag+, Mn2+, Ni2+, Pb2+, Cd2+ and Cr2+ ions under UV illumination. The metal/metal oxide-coupled ZnO NRs were characterized by scanning electron microscope, X-ray diffraction and UV-Vis diffuse reflectance. The photodegradation of RhB dye by these metal/metal oxide-coupled ZnO NRs under UV exposure was assessed.

Findings

The metal/metal oxide-coupled ZnO NRs were successfully reused to remove RhB dye in which more than >90% of RhB dye was degraded under UV exposure. Furthermore, the coupling of Ag, CuO, MnO2, Cd and Ni particles onto the surface of ZnO NRs even enhanced the degradation of dye. The dominant reactive species involved in the degradation of RhB dye were OH- and O2-free radicals.

Research limitations/implications

The coupling of metal/metal oxide onto the surface of ZnO NRs after metal ions removal could affect the photocatalytic performance of ZnO NRs in the degradation of organic pollutants in subsequent stage.

Practical implications

A good reusability performance of metal/metal oxide-coupled ZnO NRs make ZnO NRs become a desirable photocatalyst material for the treatment of wastewater, which consists of both heavy metal ions and organic dyes.

Originality/value

Metal/metal oxide coupling onto the surface of ZnO NRs particles improved subsequent UV-assisted photocatalytic degradation of RhB dye.

Details

Pigment & Resin Technology, vol. 50 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

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