Title image - The Centre for Numerical Modelling and Process Analysis

Computational Mechanics & Reliability Group

Selected Publications

TITLE:
Numerical algorithms for modelling electrodeposition: tracking the deposition front under forced convection from megasonic agitation.

AUTHORS:
M. Hughes, N. Strusevitch, C. Bailey, K. McManus, J. Kaufmann, D. Flynn, and M Desmulliez

JOURNAL:
International Journal for Numerical Methods in Fluids. V64, N3, pp 237-268 (2010)

DESCRIPTION:
The originality is the development of multi-physics models to support process design, optimisation of process variables, and design rules. The work is significant as for the first time this allowed the feasibility of using transducers in the electroplating bath to promote electro-deposition and better quality design of printed circuit boards for high performance applications. This has led to our industrial partner - Merlin Circuits - to implement this technology. Output led onto the award of the DTA Aspect Project (Funded under EP/C534212/1) which led to award of PhD for N Strusevich.

TITLE:
Finite-element simulation of stress intensity factors in solder joint intermetallic compounds.

AUTHORS:
M Alam, H. Lu, C. Bailey, and Y Chan

JOURNAL:
IEEE Transactions on Device and Materials Reliability, V9 N1. pp. 40-48, (2009)

DESCRIPTION:
Originality is the use of a fracture mechanics approach to predict crack behaviour of intermetallic compounds (IMC’s) found in solder joints. This is the first time such a numerical study has been undertaken in comparing behaviour of IMC’s in both Tin-Lead and Lead-Free Solders. This is significant as tin-lead solders are now banned under ROHS EU Legislation. Led onto a new project funded US Government (H94003-04-D-003-0056) worth US$350,000, to develop physics-of-failure models for electronic components in aerospace environments for companies such as Cassidian and Selex Galileo.

TITLE:
Modelling Methodology for Thermal Analysis of Hot Solder Dip Process.

AUTHORS:
S Stoyanov, C Bailey, M Alam, C Yin, C Best, P Tollerfield, R Crawford, M Parker, J Scott

JOURNAL:
Jnl Microelectronics Reliability, V53, pp 1055-1067, (2013)

DESCRIPTION:
Funded through a US Government Grant (H94003-04-D-003-0056/10178928), this is the first time a detailed modelling approach has been developed and validated to identify optimal process conditions for a robotic controlled hot solder dip process that will ensure leaded electronic components are reliable in safety critical applications. Provides our industrial partners with a novel qualification process for these components with potential costs savings of £100,000 per component. Work has led onto further grant (H94003-04-D-003-0056/ 10198575) to investigate unleaded components such as ball grid arrays.

TITLE:
Smeared shell modelling approach for structural analysis of heritage composite structures - An application to the Cutty Sark conservation.

AUTHORS:
S. Stoyanov, P Mason, and C. Bailey

JOURNAL:
Computers and Structures, V88. pp. 649-663, (2010)

DESCRIPTION:
New validated finite element formulation for predicting structural behaviour of composite materials in heritage ships is presented for the first time. This was used to inform the Cutty Sark Trust on how to best disassemble and reassembly this national maritime treasure which was opened by the Queen in 2012. Greenwich work was awarded best Knowledge Transfer Partnership for London in 2008, and the Times Higher Education Award for Outstanding Research Team of the year (2009). Output led onto a further project to support restoration of Medway Queen.

TITLE:
A multi-disciplinary study of vibration based reliability of lead-free electronic interconnects.

AUTHORS:
E Kamara, H Lu, C Bailey, C Hunt, D Di Maio, O Thomas

JOURNAL:
Microelectronics Reliability, 50. pp. 1706-1710, (2010)

DESCRIPTION:
The modelling work, undertaken by Greenwich, optimised the design of novel test equipment, developed at the National Physical Laboratory, to predict reliability of micro-solder joints under vibration loading. The ability to assess the reliability of lead-free solders is important to enable industry to address EU Legislation such as Reduction of Hazrdous Substance (RoHS) which bans lead-solders in consumer electronic products. Equipment is now available and work was widely disseminated to international companies through the National Physical Laboratory Industrial Advisory Board.

TITLE:
Application of Kriging and radial basis function in power electronic module wire bond structure reliability under various amplitude loading.

AUTHORS:
P Rajaguru, H Lu, C Bailey

JOURNAL:
International Journal of Fatigue, V45, pp61-67, (2012)

DESCRIPTION:
Output funded under the EU Clean Skies project PEMREL (Grant No. 271788). Reports a first in using numerical techniques to allow fast predictions of lifetime and robustness of wirebonds used in power electronic modules. Techniques have been implemented in the university developed design tool - PowerLife - which is now used by our industrial partners SEMELAB and Dynex Semiconductors. Output contributed to the group being awarded £500,000 in the new EPSRC funded project - Underpinning Power Electronics (EP/K034804/1) - where Greenwich is leading the modelling activities.

TITLE:
Design for reliability of power electronics modules.

AUTHORS:
H Lu, C Bailey, C Yin

JOURNAL:
Microelectronics Reliability, 49. pp. 1250-1255, (2009)

DESCRIPTION:
A first in presenting a physics-of-failure approach to predicting lifetime/reliability of wirebonds, solder joints and bussbars for power electronics modules. Output contributed to award of two new grants - Robustness design & health management in power electronics using damage mechanics based models (RODENT, Funded by EPSRC/IeMRC , SP/03/02/11), and the FP7 Clean Skies project PEMREL (Grant No. 271788). The output is significant as the developed models are providing our industrial partners with design rules and reliability predictions for new power electronics module designs.

TITLE:
Prognostic reliability analysis of power electronics modules.

AUTHORS:
C Yin, H Lu, M Mahera, C Bailey, M Johnson

JOURNAL:
International Journal of Performability Engineering, 6 (5). pp. 513-524, (2010)

DESCRIPTION:
Originality is in the development of fast predictions for temperature and stress within a prognostics and health monitoring framework. Output contributed to the award of two new grants - Robustness design & health management in power electronics using damage mechanics based models (RODENT, Funded by EPSRC/IeMRC , SP/03/02/11), and EU project NextFactory (Grant Number 608995). Output led to the group being invited to join the working group formulating the new IEEE standard (IEEE Std. P1856) for Prognostics and Health Management of Electronic Systems.

TITLE:
Progress towards the design and numerical analysis of a 3D microchannel 3 biochip separator.

AUTHORS:
Xiangdong Xue, Silvia Marson, Mayur K Patel, Chris Bailey, William O’Neill, David Topham, Robert W. Kay and Marc P. Y. Desmulliez

JOURNAL:
Int Journal for Numerical Methods n Bio Engineering, (2011) DOI: 10.1002/cnm.1439

DESCRIPTION:
The impact of this research has fed into a number of prototype designs and subsequent testing of 2- and 3-dimensional microfluidic biochip plasma blood separators at Cambridge University in relation to micro-flow behaviour due to geometrical changes. The work has contributed to two PhD projects and subsequently a DTA funded PhD student. Work supported by:-EPSRC Grand Challenge Project: 3D-Mintegration (EP/C534212/1). Funds:-(Total:£4.5M-UoG:£405k). Partners: University (Heriot-Watt, Cambridge, Nottingham, Loughborough) and 28 commercial organisations.

TITLE:
A Method for the Micro-encapsulation of Dielectric Fluids in Joined Polymer Shells.

AUTHORS:
C. Tonry, M. K. Patel, C. Bailey, M.P.Y. Desmuliez, S. Cargill, and W. Yu

JOURNAL:
Current Organic Chemistry, Volume 17, Number 1, January 2013 , pp. 65-71(7)

DESCRIPTION:
The significant impact of this work has led to the better understanding of a novel one-step (as opposed to multi-step) electrostatic-induced lithography process to enhance reliability, integrity, cost and time required to fabricate high-aspect ratio, hollow self-encapsulated microstructures. Outcomes of the research have fed into experimental work at the Chinese Academy of Science to demonstrate how process failures can be overcome and how these can be migrated to an industrial manufacturing process. Aspects of the research have lead to potential patenting applications which are currently being considered. Funded:-EPSRC-DTA award (EP/P504945/1) in collaboration with Heriot-Watt University.