Dr Stoyan Stoyanov BSc, MSc, PhD

Reader in Computational Engineering and Optimisation

Dr Stoyan Stoyanov is reader in computational engineering and deputy lead of the Computational Mechanics and Reliability Group at the University of Greenwich. He received his MSc degree in applied mathematics from Sofia University and obtained PhD degree in computational engineering at University of Greenwich in 2004. In 2008 he also obtained the CMI’s qualification NVQ Lev4 in Management.

As a researcher, his specialisms include the development and application of modelling technologies for thermo-mechanical reliability analysis of electronics products and microsystems, manufacturing and assembly process simulation, physics-of-failure and prognostics modelling, design optimisation, industrial data analytics and computational intelligence.

Over the past 20 years he worked on many research and consultancy projects focussed on the development and adoption of microelectronics manufacturing, electronic packaging, and component/assembly technologies, collaborating with large number of UK-based and international industrial and academic partners.

Posts Held Previously

  • 2007-2010, Senior Research Fellow, University of Greenwich
  • 2004-2007, Research Associate (KTP),  University of Greenwich
  • 2002-2004, Research Fellow, University of Greenwich

Engineering

Awards

Selected Awards

  • Best paper award at IEEE ITHERM conference, USA (2020) https://www.ieee-itherm.net/itherm/conference/best-paper-awards
  • Best paper award at IEEE EMPC conference, Italy (2019) http://www.empc2019.org/awards
  • Best paper award at the Fraunhofer Direct Digital Manufacturing Conference, Germany (2016)
  • Excellent Presentation Award at IEEE ISSE conference, Poland (2010)
  • Winner of the National Times Higher Education Award for Outstanding Engineering Research Team of the Year (2009)
  • Knowledge Transfer Collaboration award, London Development Agency (2008)
  • The University of Greenwich 2008 Early Career Research Excellence Award
  • Best Partnership Award for KTP, Technology Strategy Board (now Innovate UK) (2008)
  • IEEE CPMT (EPS) society certificate for significant contribution to the organisation of the 2nd IEEE ESTC conference (2008)

Memberships/Other

  • Senior Member of the Institute of Electrical and Electronics Engineers (IEEE)
  • Fellow of Higher Education Academy (FHEA)
  • Member of IEEE Electronics Packaging Society (EPS)
  • Member of the Steering Committee of the International Spring Seminar on Electronics Technology
  • Member of the technical committees of IEEE International conferences: ESTC, ISSE, EMPC and EuroSIME
  • Invited Lecturer on Erasmus-Mundus MSc in Smart System Integration at Heriot-Watt University (Edinburgh), HSN University College of Southeast Norway and Budapest University of Technology and Economics in Hungary (BME) (2018)
  • Reviewer for the IEEE Trans. CPMT, Microsystem Technologies, Emerald Journals

Recognition

Member of Institute of Electrical and Electronics Engineers (IEEE)

Member of Computational Intelligence Society

Member of Components, Packaging, & Manufacturing Technology(CPMT) Society

Member of the Steering Committee of the International Spring Seminar on Electronics Technology

Research / Scholarly interests

Stoyan's research focusses primarily on the development and application of computational mechanics methods for computer aided engineering (CAE) in microelectronics, micro-systems, embedded devices, etc. Research interests and expertise are in the areas of computational engineering, with focus on finite element, multi-physics and surrogate modelling, physics-of-failure analysis, numerical optimisation and machine learning.

Selected Research Projects

  • Multi-scalemicromechanicsmodellingofSAC305solders: Reliability modelling and assessment of solder joints in ball grid array packages with different solder microstructure designs
    • UK EPSRC funding, 2019-present
  • Reliability and Component Integrity Analysis: Experimental and modelling assessment of micro-ball grid array assemblies with different printed board designs and resin applications.
    • Leonardo MW funding, 2019
  • THEIA (Technically high element alignment for Focal Plane Arrays): Assessing the viability of producing high-resolution, Group III-V compound semiconductor near IR sensor arrays on conventional die placement machinery.
    • Innovate UK funding, 2017 - 2018
  • NextFactory (3D Printing): Research project on a new type of all-in-one manufacturing technology combining, for the first time, in a single piece of equipment, multi-material 3D freeform printing and ultra-precision 3D assembly
    • EU FP7 funding, 2014 - 2017
  • Technology Assessment on the Effects of Refinishing Lead-Free Microelectronic Components (four consecutive projects): Modelling and experimental assessment of the impact of refinishing electronic components – a mitigation strategy against the failure risks caused by tin whiskers - using hot solder dip, vacuum de-balling and laser re-balling processes.
    • DMEA (DoD, USA) funding, 2010 - 2014

Selected Consultancy Projects

  • Modelling the impact of embedding Cu coin into PCB on QFN’s solder joints reliability, funded by Leonardo, UK (2019)
  • FEA of BGA package, funded by Tessera, USA (2015)
  • Solder Interconnection Reliability Study, funded by GE Aviation, UK (2015)
  • Printed Circuit Board Analysis of CBGA, funded by Cassidian Electronics, Germany (2013)

Teaching

  • Module Leader on the MSc in Scientific Computing & Applicable Mathematics (2007-2018)
  • Reliability and Risk Analysis in Design (2007-2011)
  • Reliability and Optimisation (2012-2018)

Key funded projects

Research Project: Technology Assessment on the Effects of Refinishing Lead-Free Microelectronic Components (DoD Funding)

Stage 1.5+ : 06/2012-03/2013

Stage 1.5 : 10/2011-04/2012

Stage 1.0 : 10/2010-09/2011

Partners: Micross Components Limited, Selex Galileo, Rolls Royce, General Dynamics, Cassidian, CMCA, Scimus Solutions, Senelac Ltd, and Unisem Europe

Description Stage 1.5+: Thermo-mechanical Modelling of the impact of Hot Solder Dip refinishing process, Laser de- and re-balling approach to refinishing BGA components, BGA thermo-mechanical response to reflow assembly process and behaviour of 1st level solder interconnects, reliability assessment for satellite application

Description Stage 1.5: Thermo-mechanical modelling and limited experimental assessment of the impact of refinishing leadless components (BGAs, QFNs) using Micross Components' double hot solder dip process.

Description Stage 1.0: Modelling and experimental assessment of the impact of refinishing leaded components (QFP, SOP, etc) using using Micross Components' double hot solder dip process. The study of this post-manufacturing process aimed at assessing the potential risk of damage due to Hot Solder Dip (HSD)process. This process is one of the risk mitigation strategies to the tin whisker phenomenon that imposes serious risk of electronics components failure in high reliability applications.

Recent publications

Article

Xu, Yilun , Xian, Jingwei, Stoyanov, Stoyan, Bailey, Christopher , Coyle, Richard , Gourlay, Christopher , Dunne, Fionn , Nokia Bell Labs, Murray Hill, New Jersey, USA (2022), A multi-scale approach to microstructure-sensitive thermal fatigue in solder joints. Elsevier. In: , , , . Elsevier, International Journal of Plasticity, 155: 103308 ISSN: 0749-6419 (Print), (doi: https://doi.org/10.1016/j.ijplas.2022.103308).

Tilford, Tim , Stoyanov, Stoyan, Braun, Jessica, Janhsen, Jan Christoph , Patel, Mayur K. , Bailey, Chris (2021), Comparative reliability of inkjet-printed electronics packaging. IEEE. In: , , , . IEEE, IEEE Transactions on Components, Packaging and Manufacturing Technology, 11 (2) . pp. 351-362 ISSN: 2156-3950 (Print), 2156-3985 (Online) (doi: https://doi.org/10.1109/TCPMT.2021.3049952).

Stoyanov, Stoyan , Bailey, Christopher, Stewart, Paul, Parker, Mike , Roulston, John F. , Leonardo MW Ltd , Micross Components (2020), Experimental and modelling study on delamination risks for refinished electronic packages under hot solder dip loads. IEEE. In: , , , . IEEE, IEEE Transactions on Components, Packaging and Manufacturing Technology, 10 (3) . pp. 502-515 ISSN: 2156-3950 (Print), 2156-3985 (Online) (doi: https://doi.org/10.1109/TCPMT.2020.2972635).

Ahsan, M. , Stoyanov, S., Bailey, C., Albarbar, A. (2020), Developing computational intelligence for smart qualification testing of electronic products. IEEE. In: , , , . IEEE, IEEE Access, 8 . pp. 16922-16933 2169-3536 (Online) (doi: https://doi.org/10.1109/ACCESS.2020.2967858).

Hinojosa Herrera, Ana Elsa , Stoyanov, Stoyan, Bailey, Christopher, Walshaw, Christopher , Yin, Chunyan (2019), Data analytics to reduce stop-on-fail test in electronics manufacturing. De Gruyter Open. In: , , , . De Gruyter Open, Open Computer Sciences, 9 (1) . pp. 200-211 2299-1093 (Online) (doi: https://doi.org/10.1515/comp-2019-0014).

Yin, Chunyan , Stoyanov, Stoyan, Bailey, Christopher, Stewart, Paul (2019), Thermo-mechanical analysis of conformally coated QFNs for high reliability applications. IEEE. In: , , , . IEEE, IEEE Transactions on Components, Packaging and Manufacturing Technology, 9 (11) . pp. 2210-2218 ISSN: 2156-3950 (Print), 2156-3985 (Online) (doi: https://doi.org/10.1109/TCPMT.2019.2925874).

Stoyanov, Stoyan , Ahsan, Mominul, Bailey, Chris, Wotherspoon, Tracy , Hunt, Craig , Microchip Technology Inc. (2019), Predictive analytics methodology for smart qualification testing of electronic components. Springer US. In: , , , . Springer US, Journal of Intelligent Manufacturing, 30 (3) . pp. 1497-1514 ISSN: 0956-5515 (Print), 1572-8145 (Online) (doi: https://doi.org/10.1007/s10845-018-01462-9).

Tilford, Tim , Stoyanov, Stoyan, Braun, Jessica, Janhsen, Jan Cristophe , Burgard, Matthias , Birch, Richard , Bailey, Chris , Fraunhofer Institute for Manufacturing Engineering and Automation IPA, Nobelstr. 12, Stuttgart, Germany , Microsemi Corporation, Castlegate Business Park, Caldicot, Monmouthshire, UK (2018), Design, manufacture and test for reliable 3D printed electronics packaging. Elsevier Ltd.. In: , , , . Elsevier Ltd., Microelectronics Reliability, 85 . pp. 109-117 ISSN: 0026-2714 (Print), (doi: https://doi.org/10.1016/j.microrel.2018.04.008).

Stoyanov, Stoyan , Bailey, Chris, Tourloukis, Georgios (2016), Similarity approach for reducing qualification tests of electronic components. Elsevier. In: , , , . Elsevier, Microelectronics Reliability, 67 . pp. 111-119 ISSN: 0026-2714 (Print), (doi: https://doi.org/10.1016/j.microrel.2016.10.017).

Stoyanov, S. and , Bailey, C. (2015), Modelling the impact of refinishing processes on COTS components for use in aerospace applications. Elsevier. In: , , , . Elsevier, Microelectronics Reliability, 55 (9-10) . pp. 1271-1279 ISSN: 0026-2714 (Print), (doi: https://dx.doi.org/10.1016/j.microrel.2015.07.030).

Yin, Chunyan , Best, Chris, Bailey, Chris, Stoyanov, Stoyan (2015), Statistical analysis of the impact of refinishing process on leaded components. Elsevier Ltd.. In: , , , . Elsevier Ltd., Microelectronics Reliability, 55 (2) . pp. 424-431 ISSN: 0026-2714 (Print), (doi: https://doi.org/10.1016/j.microrel.2014.11.001) NB Item availability restricted.

Book

Bailey, Christopher , Stoyanov, Stoyan, Lu, Hua (2017), Co-design And Modelling For Advanced Integration And Packaging: Manufacturing And Reliability. World Scientific Publishing. In: , , , Co-Design and Modelling for Advanced Integration and Packaging. World Scientific Publishing, . ISBN: 9789814740203ISSN: 2315-473X (Print), (doi: https://doi.org/10.1142/9900).

Conference proceedings

Stoyanov, Stoyan and , Bailey, Chris (2022), Deep learning modelling for composite properties of PCB conductive layers. Institute of Electrical and Electronics Engineers (IEEE). In: , , , 2022 23rd International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE). Institute of Electrical and Electronics Engineers (IEEE), Piscataway, New Jersey (1st) . pp. 1-7 . ISBN: 9781665458375 (doi: https://doi.org/10.1109/EuroSimE54907.2022.9758885).

Stoyanov, Stoyan , Stewart†, Paul, Bailey, Christopher (2021), Reliability optimisation and lifetime modelling of micro-BGA assemblies in harsh environment applications. Institute of Electrical and Electronics Engineers (IEEE). In: , , In: Paul Stewart (ed.), 2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC). 13-16 Sept. 2021. Gothenburg, Sweden. Institute of Electrical and Electronics Engineers (IEEE), Piscataway, New Jersey (1st) . pp. 1-8 . ISBN: 9780956808677 ; 9781665423687 (doi: https://doi.org/10.23919/EMPC53418.2021.9584970).

Stoyanov, Stoyan , Bailey, Christopher, Waite, Rhys, Hicks, Christopher , Golding, Terry , Microchip Technology Inc (Microsemi) , Amethyst Research Inc (2020), Packaging challenges and reliability performance of compound semiconductor focal plane arrays. IEEE. In: , , , 2019 22nd European Microelectronics and Packaging Conference & Exhibition (EMPC). IEEE, . pp. 1-8 . ISBN: 9780956808660 (doi: https://doi.org/10.23919/EMPC44848.2019.8951842).

Hinojosa Herrera, Ana Elsa and , Stoyanov, Stoyan (2019), Data driven predictive model to compact a production stop-on-fail test set for an electronic device. IEEE Xplore. In: , , , Proceedings of the 2018 International Conference on Computing, Electronics & Communications Engineering (iCCECE). IEEE Xplore, . pp. 59-64 . ISBN: 9781538649046 (doi: https://doi.org/10.1109/iCCECOME.2018.8658941).

Ahsan, Mominul , Stoyanov, Stoyan, Bailey, Christopher (2018), Data driven prognostics for failure of power semiconductor packages. IEEE Xplore. In: , , , Proceedings of 41st Spring Seminar on Electronics Technology (ISSE). IEEE Xplore, . pp. 1-6 . ISBN: 9781538657300 2161-2536 (Online) (doi: https://doi.org/10.1109/ISSE.2018.8443612).

Stoyanov, Stoyan , Ahsan, Mominuil, Bailey, Chris (2018), Data analytics approach for optimal qualification testing of electronic components. IEEE Xplore. In: , , , Proceedings EuroSimE 2018. IEEE Xplore, . pp. 1-9 . ISBN: 9781538623589 (doi: https://doi.org/10.1109/EuroSimE.2018.8369926).

Yin, Chunyan , Stoyanov, Stoyan, Bailey, Christopher, Stewart, Paul (2017), Modelling the impact of conformal coating penetration on QFN reliability. IEEE. In: , , , 2017 18th International Conference on Electronic Packaging Technology (ICEPT). IEEE, . pp. 1021-1026 . ISBN: 9781538629734 (doi: https://doi.org/10.1109/ICEPT.2017.8046616).

Stoyanov, Stoyan and , Bailey, Christopher (2017), Machine learning for additive manufacturing of electronics. IEEE. In: , , , Proceedings 2017 40th International Spring Seminar on Electronics Technology (ISSE). IEEE, . ISBN: 9781538605837 2161-2536 (Online) (doi: https://doi.org/10.1109/ISSE.2017.8000936).

Tilford, T. , Stoyanov, S., Tourloukis, G., Bailey, C. (2016), Numerical analysis of droplet deposition in inkjet printed electronics assembly. IEEE. In: , , , 2016 17th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE). IEEE, . pp. 1-7 . ISBN: 9781509021062 (doi: https:// doi.org/10.1109/EuroSimE.2016.7463358).

Bailey, C. , Stoyanov, S., Tilford, T., Tourloukis, G. (2016), Modelling methodologies for quality assessment of 3D inkjet printed electronic products. Fraunhofer Verlag. In: , , In: Bernhard Müller (ed.), 3rd Fraunhofer Direct Digital Manufacturing Conference, DDMC 2016. Proceedings. Fraunhofer Verlag, Stuttgart . ISBN: 9783839691281 978-3-8396-1001-5 (Online) (doi: https://www.verlag.fraunhofer.de/bookshop/artikel.jsp?v=245111).

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