Cyclic voltammetric measurements were recorded on various synthetic electroless copper plating baths. The shapes of the current potential curves were observed as various…
Abstract
Cyclic voltammetric measurements were recorded on various synthetic electroless copper plating baths. The shapes of the current potential curves were observed as various components of the bath were added to an alkaline Cu‐EDTA solution. Peak potentials, Ep, were measured to identify the various species undergoing oxidation or reduction.
Yingxin Goh, A.S.M.A. Haseeb and Mohd Faizul Mohd Sabri
The purpose of this paper is to enhance the understanding on the electrodeposition of various lead (Pb)‐free solder alloys, so that new studies can be carried out to solve…
Abstract
Purpose
The purpose of this paper is to enhance the understanding on the electrodeposition of various lead (Pb)‐free solder alloys, so that new studies can be carried out to solve processing issues.
Design/methodology/approach
The paper reviews the available reports on the electrodeposition of tin (Sn)‐based solder systems and identifies the challenges in this area.
Findings
Compositional control remains a major challenge in this area, where the achievement of desired composition for binary and ternary alloys is subjected to uncertainties. The use of chelating agents in the bath and optimization of parameters can assist the achievement of near‐desired alloy composition. Acidic plating baths are preferred due to their compatibility with photoresists but oxidation of stannous ions causes poor bath stability. Antioxidants, reducing agents and low oxygen overpotential anodes can suppress the oxidation rate and increase the lifespan of plating baths. Apart from chelating agents and antioxidants, various categories of additives can be added to improve quality of deposits. Surfactants, grain refiners and brighteners are routinely used to obtain smooth, fine‐grained and bright deposits with good thermo‐mechanical properties.
Originality/value
The paper provides information on the key issues in electrodeposition of Pb‐free solder alloys. Possible measures to alleviate the issues are suggested so that the electrodeposition technique can be established for mass production of a wider range of solder alloys.
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A.P. Srikanth, V. Raman, S. Tamilselvi, S. Nanjundan and N. Rajendran
This paper aims to investigate the protection efficiency of a thin film of electrochemically synthesized conducting polymers, such as poly m‐toluidine, poly N‐methyl aniline, and…
Abstract
Purpose
This paper aims to investigate the protection efficiency of a thin film of electrochemically synthesized conducting polymers, such as poly m‐toluidine, poly N‐methyl aniline, and its copolymer, poly (aniline‐co‐N‐methyl aniline) (PANINMA), on plain carbon steel in 0.1 M HCl. It also attempts to compare the protection efficiency of these compounds with polyaniline (PANI)‐coated carbon steel.
Design/methodology/approach
The green coloured and adherent coatings were obtained by cyclic voltammetry during sequential scanning of the potential region between −0.6 and 1.6 V at a scan rate of 10 mVs−1. Potentiodynamic polarization measurement (DC) was used to obtain an estimate of the corrosion rate and protection efficiency for these electrodeposited polymers on the carbon steel. Scanning electron micrographs (SEM) also were obtained to characterize the deposited coatings.
Findings
It was observed that these polymer coatings showed better protection efficiency than the PANI coating. Of the compounds studied, the copolymer PANINMA coating showed higher protection efficiency than other coatings. The SEM observations revealed that the compact continuous dense morphology of PANINMA provided better protection than other coatings.
Originality/value
This paper explains the protection efficiency of the substituted and copolymer coatings of PANI on carbon steel.
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C. Giacomelli, F.C. Giacomelli, J.A.A. Baptista and A. Spinelli
The effect of oxalic acid (OA) on corrosion resistance of carbon steel in sulphuric acid pH=2.5‐6.0 solutions containing 10−7‐10−3M OA was investigated by means of potentiodynamic…
Abstract
The effect of oxalic acid (OA) on corrosion resistance of carbon steel in sulphuric acid pH=2.5‐6.0 solutions containing 10−7‐10−3M OA was investigated by means of potentiodynamic polarisation measurements and immersion tests. The results suggest that OA is a good corrosion inhibitor for carbon steel, exhibiting inhibition efficiencies (IE) ranging from 50 to 85 per cent in dilute 10−7‐10−5M OA solutions of pH>3.0, whereas for pH≤3.0 solutions, an increase in corrosion rate was found. Non‐accelerated experiments (weight loss tests) carried out by immersing carbon steel specimens into OA‐containing solutions during at least 6 h revealed only positive IE values, regardless of both solution pH and OA content. The results were explained considering the solution composition as function of pH.
The purpose of this paper is to evaluate and compare the protective, anticorrosion properties of silane- and polyrhodanine-based bilayer coatings pRh/IBTES and IBTES/pRh on an…
Abstract
Purpose
The purpose of this paper is to evaluate and compare the protective, anticorrosion properties of silane- and polyrhodanine-based bilayer coatings pRh/IBTES and IBTES/pRh on an X20Cr13 stainless steel substrate.
Design/methodology/approach
IBTES/pRh and pRh/IBTES have been coated using the dip-coating method and the cyclic voltammetry technique. The electrochemical measurements have been used to assess the anticorrosion properties of the resulting bilayer coatings. Morphological and chemical characterizations have been performed using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS).
Findings
The results clearly show that the combination of both the deposits of polyrhodanine and silane yields a more protective structure that affords better protection against corrosion with time. The best barrier properties are achieved by the substrates coated with polyrhodanine film upon which silane is subsequently adsorbed – the pRh/IBTES bilayer coating.
Originality/value
The paper reveals that the procedure of modification of silane films with polyrhodanine had a marked effect on the anti-corrosive performance of the obtained two types of bilayers coatings (pRh/IBTES, IBTES/pRh) applied on a stainless steel surface. The coating where polyrhodanine was first electrodeposited on the steel surface and then the silane layer adsorbed (pRh/IBTES) achieved the best protective properties.
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Ashutosh Sharma and Byungmin Ahn
The purpose of this paper is to investigate the influence of pulse plating current density on the morphology and solderability of Pb-free Sn-Cu solder coatings prepared from…
Abstract
Purpose
The purpose of this paper is to investigate the influence of pulse plating current density on the morphology and solderability of Pb-free Sn-Cu solder coatings prepared from alkaline stannate baths.
Design/methodology/approach
Sn-Cu solder coatings were produced from a plating solution containing sodium stannate, copper stannate, sodium hydroxide and sorbitol additive on copper substrates. The pulse plating experiments were conducted in galvanostatic mode. The plating current density was varied from 5 to 25 mA/cm2, and the morphology of the coatings was studied. The solderability of the coatings was assessed by spread ratio measurement after reflowing the solder coatings at 250°C.
Findings
The composition control of eutectic solders is always a challenge in plating. The findings show that Sn-Cu coatings prepared by pulse plating are composed of tetragonal ß-Sn structure and Cu6Sn5 compounds irrespective of bath composition and conditions. The final coatings were very dense and smooth with nodular morphology. It was shown that a eutectic composition can be achieved if we apply a current density of ∼15-20 mA/cm2. The solderability studies suggest that solder coatings plated at and beyond 15 mA/cm2 are more suitable for solder finish applications.
Originality/value
The work presents key issues in pulse electroplating of Sn-Cu solder coatings from an alkaline bath. Possible strategies to control the eutectic Sn-Cu composition by plating process are recommended.
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H. Abd El‐Wahab, F. Abd El‐Hai, M. Abd El‐Fattah and L. Lin
Demands for coatings with superior technical characteristics have induced the use of composite coatings, which usually represent an extremely strong product. The resin blend…
Abstract
Purpose
Demands for coatings with superior technical characteristics have induced the use of composite coatings, which usually represent an extremely strong product. The resin blend technique is a simple and useful method for improving paint properties. Coal tar resins are the most economical coating extensively used in the industry; short oil‐length alkyd resins are usually used for air and force‐dry industrial coatings for metal surfaces. The purpose of this paper is to evaluate coating blends composed of these resins, in particular, the effects of short oil‐length alkyd additive on the properties of coal tar binder.
Design/methodology/approach
One way to achieve new types of binders is to make combinations of the existing ones, in an ideal case retaining the desirable properties of both. The alkyd has important properties over the original drying oil. To achieve the goal of improving coal tar resin properties, short oil‐length alkyd was blended with it. The prepared short oil‐length alkyd was characterised using IR and 1HNMR spectroscopy. The mixing ratio of short oil‐length alkyd with coal tar was up to 25 per cent. The compatibility of coating blend was characterised by scanning electron microscope. The physical, mechanical and chemical properties of the coating blend in addition to the corrosion resistance were determined according to ASTM methods.
Findings
In spite of a large number of synthetic resins being available for use in paint formulations, the alkyd resins surpassed all of them in versatility and low cost. The blend of short oil‐length alkyd resin with coal tar has yielded better coating blend properties. The coating blend showed significant enhancement of physical, mechanical and chemical properties such as gloss, drying time, adhesion, scratch hardness, acid and solvent resistance because the coating blend combines the properties of thermosetting and thermoplastic resins.
Research limitations/implications
Alkyd resins are the most extensively used synthetic polymers in the coating industry. Modification of coal tar blend based on other type of polyester resins could also be studied in order to assess the applicability of the coal tar blend system found for other applications.
Practical implications
These types of alkyd resins can be applied in other bitumen composites as additives and reinforce agent.
Originality/value
The paper shows how the low‐cost modified coal tar binder can be used for air and force‐dry industrial coatings for metal surfaces.
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Eric C.C. Yan, S.W. Ricky Lee and X. Huang
This paper presents an experimental study to assess the reliability of solder ball attachment to the bond pads of PBGA substrate for various plating schemes. The basic structure…
Abstract
This paper presents an experimental study to assess the reliability of solder ball attachment to the bond pads of PBGA substrate for various plating schemes. The basic structure of the under bump metallisation is Cu/Ni/Au. Three different kinds of electroless plating solutions are used to deposit the Ni layer, namely, Ni‐B, Ni‐P (5 per cent), and Ni‐P (10 per cent). Also, conventional electrolytic Ni/Au plating is performed to provide a benchmark. After solder ball attachment, mechanical tests are conducted to characterize the ball shear strength for comparison. Furthermore, some specimens are subjected to multiple reflows to investigate the thermal aging effect.
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Z. Pruszowski, P. Kowalik, M. Cież and J. Kulawik
The purpose of this paper is to characterize electrical parameters of amorphous Ni‐P resistive layers used for fabrication of precise resistors.
Abstract
Purpose
The purpose of this paper is to characterize electrical parameters of amorphous Ni‐P resistive layers used for fabrication of precise resistors.
Design/methodology/approach
Ni‐P resistive layers were produced by the chemical process in water solution using Ni2 + and H2PO2− ions. The paper presents the results of the studies concerning the influence of bath acidity and conditions of thermal stabilization on the structure and temperature coefficient of resistance of Ni‐P alloy.
Findings
The temperature coefficient of resistance of amorphous Ni‐P layers was found to depend significantly on the parameters of chemical metallisation process. It was stated that the changes of through‐casing resistivity versus the acidity of technological solution have roughly parabolic characteristics.
Originality/value
In this paper, it was at first explained how the changes of the structure of Ni‐P resistive layers depend on their temperature coefficient of capacitance.