Now showing 1 - 7 of 7
  • Publication
    The effect of Al micro-alloying on corrosion and thermal properties of Sn-Zn alloy
    (Trans Tech Publications Ltd., 2020)
    Nordarina Jumali
    ;
    Nurwahida Mohd Zaini
    ;
    Nur Syamira Sa'don
    ;
    Ahmad Azmin Mohamad
    ;
    Electrochemical corrosion behavior of Sn–Zn solder alloys in 6 M potassium hydroxide solution was investigated by potentiodynamic polarization technique, aiming to investigate the role of Al additions. The effect of micro-alloying Al on the thermal properties was also studied by using DSC. The results reveal that the presence of Al content leads to increasing in corrosion potential yet reducing the corrosion current density and passivation current density, simultaneously. XRD analysis reveals the failure to produce new compound with Zn, limits the effect of adding Al towards the corrosion performance. Yet, significant improvement on thermal properties were seen, especially on the melting temperature and pasty range without modifying the eutectic melting behavior.
  • Publication
    Microstructural analysis of Sn-3.0Ag-0.5Cu-TiOâ‚‚ composite solder alloy after selective electrochemical etching
    (IOP Publishing, 2020-01)
    Muhamad Zamri Yahaya
    ;
    ;
    Soorathep Kheawhom
    ;
    Balázs Illés
    ;
    Agata Skwarek
    ;
    Ahmad Azmin Mohamad
    This work aims to provide deep morphological observation on the incorporated TiO₂ nanoparticles within the SAC305 by selective electrochemical etching. Cyclic voltammetry and chronoamperometry were used to investigate the selective etching performances. The removal of β-Sn matrix was conducted at a fixed potential of-350 mV. Average performances of 2.19 and 2.30 mA were attained from the chronoamperometry. The efficiency of β-Sn removal was approved according to the reduction of the intensities on the phase analysis. Successful observation of the TiO₂ near the Cu6Sn5 layer was attained for an optimum duration of 120 s. Clusters of TiO₂ nanoparticles were entrapped by Cu6Sn5 and Ag3Sn intermetallic compound (IMC) layer network and at the solder/substrate interface. The presence of TiO₂ nanoparticles at the solder interface suppresses the growth of the Cu6Sn5 IMC layer. The absence of a β-Sn matrix also allowed in-depth morphological observations to be made of the shape and size of the Cu6Sn5 and Ag3Sn. It was found that TiO₂ content facilitates the β-Sn removal, which allows better observation of the IMC phases as well as the TiO₂ reinforcement particles.
  • Publication
    Effect additions Zn on Sn-0.7Cu lead-free solder: a short brief
    (IOP Publishing, 2020)
    Fatin Sufina Mohd Tarmizi
    ;
    Mohamad Najmi Masri
    ;
    ;
    Ahmad Azmin Mohamad
    Sn-0.7Cu lead-free solder is an alternative solder material that suitable to replace Sn-Pb solder in electronic manufacturing. However, it has a weakness of high melting temperature and lower mechanical strength. In this study, the change in microstructure, elements, the structural and melting point of Sn-0.7Cu after the addition of different compositions of Zn element was discussed. The result shows that after adding a small amount of Zn, a refinement microstructure of Sn-0.7Cu-xZn solder alloy was obtained, and the melting point of the solder decreased from 227.7 °C to 225.7 °C. Besides, the formation new phase of was investigated by scanning electron microscope (SEM) followed by energy-dispersive x-ray spectroscopy (EDX) and x-ray diffraction (XRD). Besides, the behaviour of Sn-0.7Cu-xZn solder alloy can be further studied via open circuit potential (OCP) to determine the corrosion potential.
      31  2
  • Publication
    Selective etching and hardness properties of quenched SAC305 solder joints
    (Emerald, 2020)
    Muhamad Zamri Yahaya
    ;
    Nor Azmira Salleh
    ;
    Soorathep Kheawhom
    ;
    Balazs Illes
    ;
    ;
    Ahmad Azmin Mohamad
    Purpose: The purpose of this paper is to investigate the morphology of intermetallic (IMC) compounds and the mechanical properties of SAC305 solder alloy under different cooling conditions. Design/methodology/approach: SAC305 solder joints were prepared under different cooling conditions/rates. The performance of three different etching methods was investigated: simple chemical etching, deep etching based on the Jackson method and selective removal of β-Sn by a standard three-electrode cell method. Phase and structural analyses were conducted by X-ray diffraction (XRD). The morphology of etched solder was examined by a field emission scanning electron microscope. The hardness evaluations of the solder joints were conducted by a Vickers microhardness tester. Findings: The Ag3Sn network was significantly refined by the ice-quenching process. Further, the thickness of the Cu6Sn5 layer decreased with an increase in the cooling rate. The finer Ag3Sn network and the thinner Cu6Sn5 IMC layer were the results of the reduced solidification time. The ice-quenched solder joints showed the highest hardness values because of the refinement of the Ag3Sn and Cu6Sn5 phases. Originality/value: The reduction in the XRD peak intensities showed the influence of the cooling condition on the formation of the different phases. The micrographs prepared by electrochemical etching revealed better observations regarding the shape and texture of the IMC phases than those prepared by the conventional etching method. The lower grain orientation sensitivity of the electrochemical etching method (unlike chemical etching) significantly improved the micrographs and enabled accurate observation of IMC phases.
      17  1
  • Publication
    Effect of surface-treated filler on the wettability of composite solder: short review
    (Springer, 2023)
    Wan Hafizah Mohd Saufee
    ;
    Wai Keong Leong
    ;
    Ahmad Azmin Mohammad
    ;
    This paper evaluates and analyzes the effect of surface-treated filler on the wettability of composite solder. The basic concepts, key variables, arrangement, and most recent advances on wettability effect of selected surface treatment of ceramic-reinforced composite lead-free solder will be covered. The wettability characteristics of solders serve as the connection between the ceramic support and were found to be significantly improved by the ceramic filler with surface treatment as it minimizes the agglomeration caused by density differences and the Van der Waals attraction force. After the surface modification procedure, it was also possible to see the good dispersion of ceramic reinforcement in the solder as it assists filler in overcoming the Van der Waals attraction on the particle. Based on ultrasonic, electroless plating, and pyrolysis treatment that have been reviewed, the wettability of the composite solder is observed to be better than the untreated or initial pure solder without filler as surface treatment helps filler molecules effectively confine the mobility of the grain boundaries due to excellent interfacial bonding with Zener pinning effect. In solder, where mechanical aspect is one of the most important properties, substantial advancements in mechanical qualities have partially resulted from surface treatment of the ceramic reinforcement. Study on filler surface treatment has beneficially influences the improvement of the ceramic reinforcement-solder interfacial response and opens prospects for more specific future research lines and composite solder application opportunities as the response from surface treatment greatly impact the solder’s wettability and its reliability as lead-free solder (LFS) product that can substitute the traditional lead-based solder.
      2  2
  • Publication
    Corrosion Investigation of Sn-0.7Cu Pb-Free solder in open-circuit and polarized conditions
    (IOP Publishing, 2020)
    Mohd Zohirul Haziq Aziz
    ;
    Nasihah Zainon
    ;
    Ahmad Azmin Mohamad
    ;
    The corrosion performance of Sn-0.7Cu solder alloy was investigated in 1 M hydrochloride acid by means of open-circuit potential and potentiodynamic polarization techniques. In open-circuit potential measurement, the potential showed almost constant reading after achieving potential -550 mV, consistent with single dissolution peak observed in potentiodynamic polarization. This revealed single element dissolution process of Sn took place. Supporting morphological and phase analyses were done by using scanning electron microscope and X-ray diffraction. Phase analysis confirmed the corrosion product are SnO and SnO2. Morphological analysis showed two type of oxide layer formed as corrosion product, which are compact oxide layer and loose rod-like oxide layer after polarization, while rod-like corrosion product was diminished in open-circuit condition. This indicate that complete protection from further corrosion was impossible due to the incomplete passivation layer formation in potentiodynamic polarization.
      1  15
  • Publication
    The effect of Bismuth addition on Sn-Ag-Cu lead-free solder properties: a short review
    (IOP Publishing, 2020)
    M Muhamad
    ;
    MN Masri
    ;
    ;
    AA Mohamad
    Sn-0.7Ag-0.5Cu lead-free solder is an alternative solder material suitable to replace Sn-Pb solder in electronic manufacturing. In this review, the change in the microstructure, elements, the structural and melting point of Sn-0.7Ag-0.5Cu after the addition of different compositions of bismuth were discovered. Besides, the influence of bismuth in lead-free solder alloys attracts to be studied due to its capability to improve the wettability and solder spread.
      2  21