Research opportunities supervised by Dr Ee-Hua Wong include:
Email supervisor: ee-hua.wong@canterbury.ac.nz
Reliability of Microelectronics Packaging
Introduction
Advancement in microelectronics is responsible for the transformations in computers, communication, and consumable electronics we used in the last three decades. In the heart of these transformations are the miniaturisation of the microelectronics and its packaging.
The sustained high interest, and hence high research activities, in the reliability of microelectronics packaging is attributed to new failure mechanisms brought about by (a) the increasing complexity of microelectronic packaging (e.g. 3-D through silicon via technology) and (b) the reducing robustness of microelectronic packaging due to the reduced dimensions of the structural elements/interfaces (e.g. via pads, solder joints; etc.) or the use of new sustainable materials that are weaker in structural strength (e.g. some lead free solders) or are more susceptible to environment (e.g. halogen free laminates).
Research focus: Drop-impact reliability of microelectronic packaging
The increased portability of electronics products made possible by minitualisation of microelectronics has rendered the electronic components and the interconnections within vulnerable that is aggravated by the adoption of lead-free solders, which tends to be more vulnerable to high strain rate loading such as the case of drop-impact. A fundamental understanding of the propagation of cracks in the solder joints under the condition of low cycle fatigue at high strain rate is needed to develop a predictive model for the drop-impact life of the solder joints in portable electronic products. This research will build upon the previous research performed under consortium projects with Philips, NXP Semiconductor, Freescale Semiconductor, ASE Group, and Nihon Superior.
Qualifications: Candidates with interest in mechanics of materials are encouraged to write in.
Funding: Funding will be available for student with suitable qualification.
Collaboration: Arrangement will be made for the successful candidate/s to be attached to one of the companies for a period of time during the course of the research.
Damage Mechanism of Fibre Reinforced Plastic
Introduction
The high strength and stiffness to weight characteristic of Fibre Reinforced Plastic (FRP) has led to its increasing “green” applications. Principally motivated by huge saving in fuel, the next generation of Dreamliner by Boeing will have 50% of its structural element made of FRP. The turbine blades of all megawatt wind turbines are inevitably made of FRP that reduces the inertia of the turbine, thus improving its ability to harvest energy from dynamic winds. Similar trend is also observed in marine renewable applications where FRP has the additional advantage of being resistant to salt water.
Research
a. Investigating the failure of fibre reinforced plastic under the condition of bi-axial loading.
An accurate definition of the fracture strength of FRP is necessary to optimise its “green” functionality while not compromising the safety of the structural elements it is made of. While there has been abundant data on the fracture strength of FRP under the condition of controlled uniaxial loading, there is scant data on its fracture strength under the condition of bi-axial loading. On the other hand, almost all structural elements experience multi-axial loading in real applications. This research aims to develop more understanding in the bi-axial fracture strength of FRP through experimental mechanical characterisation and supported by macro and micro scale analysis of the evolution of damage and the eventual fracture. Candidates with interest in mechanics and (nano) composite are encouraged to write in.
b. Investigating the fatigue propagation of adhesives bonds used for joining FRP elements.
Adhesives bonds are used extensively to join FRP elements in wind turbine. There is also very strong motivation to replace the bolted joints found extensively in the commercial aircrafts with adhesive bonds that has the potential to reduce 50% of the joint weight. However, adhesive bonds tend to become the weakest link of the structure. This research aims to investigate the propagation of crack in the adhesive for a range of normal-shear loading ratios under the condition of cyclic loading. The effect of moisture on the crack propagation, including the anisotropic diffusion of moisture in FRP and the hygroscopic swelling of FRP, will also be investigated.
Qualification: Candidates with interest in mechanics of materials are encouraged to write in.
Funding: Funding will be available for student with suitable qualification.
Collaboration: This research will be in collaboration with Nanyang Technological University, and arrangemenst will be made for the successful candidate/s to be attached to the university for a period of time during the course of the research.
Wind and Marine Renewable Energy
Climate change is increasingly being acknowledged as the most critical threat to mankind. Many regions are setting clear targets on the contribution of renewable energy to the total energy consumption.
Research:
a. Wind-wave-structural interaction
Offshore wind offers the advantage of better wind condition and abundant of area. On the other hand, installation wind turbine offshore, especially in deep water, does post many challenges. One of the key challenge is the combined loading of wind turbine by wind and wave. This research aims to investigate the response of wind turbine – both bottom fixed and floating - to wind-wave loading.
b. Innovative energy harvesting device
While the technology for wind energy harvesting is relatively matured, there is no stopping good innovation. On the other hand, marine energy harvesting is relatively immature and there is much room for innovation and exploration. This research aims to build upon in-depth understanding in the physics of wind, tidal, and wave to develop innovative energy harvesting devices that will advance the technology of wind/wave energy harvesting.
Qualification: For research (a), candidates with interest in computational mechanics are encourage to write in. For research (b), candidates with interest in energy and design are encouraged to write in.
Funding: Funding will be available for student with suitable qualification.
Collaboration: This research will be in collaboration with Nanyang Technological Universit,y and arrangemenst will be made for the successful candidate/s to be attached to the university for a period of time during the course of the research.