Quasi-ambient bonding to enable cost-effective high temperature Pb-free solder interconnects
Lead Research Organisation:
University of Manchester
Department Name: Materials
Abstract
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Publications
Bekaert J
(2020)
Enhanced Superconductivity in Few-Layer TaS2 due to Healing by Oxygenation.
in Nano letters
Bell E
(2022)
Directed evolution of an efficient and thermostable PET depolymerase
in Nature Catalysis
Cai W
(2019)
Solution-Processed HfO x for Half-Volt Operation of InGaZnO Thin-Film Transistors
in ACS Applied Electronic Materials
Conlan AP
(2020)
Direct measurement of TEM lamella thickness in FIB-SEM.
in Journal of microscopy
Hopkinson DG
(2019)
Formation and Healing of Defects in Atomically Thin GaSe and InSe.
in ACS nano
Naab B
(2024)
Fatigue prediction through quantification of critical defects and crack growth behaviour in additively manufactured Ti-6Al-4V alloy
in Materials Science and Engineering: A
Ramachandran S
(2021)
Application of Imaging Techniques to Determine the Post-Yield Behaviour of the Heterogeneous Microstructure of Friction Stir Welds
in Experimental Mechanics
Ramachandran S
(2022)
Fast in-situ synchrotron X-ray imaging of the interfacial reaction during self-propagating exothermic reactive bonding
in Materialia
| Description | This grant generated significant new knowledge regarding the microstructural characteristics and the factors affecting the microstructure for QAB joints employing Ni-Al nano-foils. Key to achieving this was development of a new experimental set-up for synchrotron studies of the bonding process at high time resolution, supported by numerical analysis of the bonding. This generated new proposals for improving the integrity of lead-free bonding joints by application of pressure and surface treatments, proving opportunities for improving the stability and integrity of electronic bonding processes without using harmful elements like lead in the bonding process. |
| Exploitation Route | We hope our research concepts for improving bond integrity will be tested at larger scale by partners in the power electronics industry, likely through the project industrial partners in due course for die-attach and baseplate bonding. Additionally our research has developed an experimental set-up for high speed imaging of bond formation that could be applied to other pulse triggered materials and processes. |
| Sectors | Aerospace Defence and Marine Digital/Communication/Information Technologies (including Software) Electronics Energy Manufacturing including Industrial Biotechology |
| Description | The project industrial collaborators have expressed their great interest in exploitation of the potential research findings, and will to support from various angles to make use of the technologies to be developed. With the existing industrial collaborators, we have recently expanded the potential uses of the QAB process for bonding different substrates including power module baseplates with the aim to reduce the damage caused by differences in the thermal expansion of neighbouring components. |
| First Year Of Impact | 2021 |
| Sector | Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Electronics,Manufacturing, including Industrial Biotechology |
| Impact Types | Economic |
| Description | A Smart Automated TEM Facility for Large Scale Analysis of Atomic Structure and Chemistry |
| Amount | £5,857,335 (GBP) |
| Funding ID | EP/X041204/1 |
| Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 08/2023 |
| End | 08/2025 |
| Title | Advanced simulation tool for QAB bonding process analysis |
| Description | Phase field models has been established to underpin the fundamental understanding of relevant phenomena associated with QAB bonding and performance of bonded structures, e.g. void formation, incurred residual stress, and their effects on reliability of the bonds. |
| Type Of Material | Improvements to research infrastructure |
| Year Produced | 2020 |
| Provided To Others? | No |
| Impact | The notable impacts include: i) provide detailed SPER bonding process in terms of liquid-solid interfacial interactions/reactions; ii) quantitively evaluation of internal voids and their formation, as well as resultant residual stresses; ii) the tool may be applicable to the potential applications to enable understanding the phenomena of multi-scale and multi-phase interactions in the manufacturing. |
| Title | Supplementary information files for Fast in-situ synchrotron X-ray imaging of the interfacial reaction during self-propagating exothermic reactive bonding |
| Description | Supplementary files for article Fast in-situ synchrotron X-ray imaging of the interfacial reaction during self-propagating exothermic reactive bonding Self-Propagating Exothermic Reactive (SPER) bonding with lead-free solders is potentially attractive for microelectronics assembly due to its highly localised heating and minimal thermal loading of the components and substrates. The transient dynamics of melting, wetting, solidification and defect formation during SPER bonding were observed using in-situ synchrotron X-ray imaging with sub-millisecond temporal resolution and the results were further analysed using electron microscopy and thermal modelling. In-situ imaging revealed the preferential melting of the solder and subsequent wetting of the substrate. Numerous air bubbles were observed to form at the bonding interface. The distribution of these bubbles was found to vary with the thermal conductivity and wettability of the substrates. These bubbles appear to reduce the effectiveness of bonding by promoting the formation of cracks and voids within the solder joint. Our results show that metallisation layers on the bonding substrate can influence the dynamics of melting for the solder materials and thereby directly influence the reliability of SPER interconnects. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://repository.lboro.ac.uk/articles/dataset/Supplementary_information_files_for_Fast_in-situ_syn... |
| Title | Supplementary information files for Fast in-situ synchrotron X-ray imaging of the interfacial reaction during self-propagating exothermic reactive bonding |
| Description | Supplementary files for article Fast in-situ synchrotron X-ray imaging of the interfacial reaction during self-propagating exothermic reactive bonding Self-Propagating Exothermic Reactive (SPER) bonding with lead-free solders is potentially attractive for microelectronics assembly due to its highly localised heating and minimal thermal loading of the components and substrates. The transient dynamics of melting, wetting, solidification and defect formation during SPER bonding were observed using in-situ synchrotron X-ray imaging with sub-millisecond temporal resolution and the results were further analysed using electron microscopy and thermal modelling. In-situ imaging revealed the preferential melting of the solder and subsequent wetting of the substrate. Numerous air bubbles were observed to form at the bonding interface. The distribution of these bubbles was found to vary with the thermal conductivity and wettability of the substrates. These bubbles appear to reduce the effectiveness of bonding by promoting the formation of cracks and voids within the solder joint. Our results show that metallisation layers on the bonding substrate can influence the dynamics of melting for the solder materials and thereby directly influence the reliability of SPER interconnects. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://repository.lboro.ac.uk/articles/dataset/Supplementary_information_files_for_Fast_in-situ_syn... |
| Description | ISCF-DER Challenge centre partnership |
| Organisation | Manufacturing Technology Centre (MTC) |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | As an academic partner within the consortium the team has contributed invariably in the preparation of the relevant technical attributes to the DER centre biding team. |
| Collaborator Contribution | Our partner had been working and co-ordinating the application and the relevant activities. |
| Impact | The panel interview has be conducted by UKRI, and the result will be confirmed shortly by this week. |
| Start Year | 2020 |
| Description | ISCF-DER Challenge centre partnership |
| Organisation | University of Nottingham |
| Department | Nottingham Clinical Trials Unit (NCTU) |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | As an academic partner within the consortium the team has contributed invariably in the preparation of the relevant technical attributes to the DER centre biding team. |
| Collaborator Contribution | Our partner had been working and co-ordinating the application and the relevant activities. |
| Impact | The panel interview has be conducted by UKRI, and the result will be confirmed shortly by this week. |
| Start Year | 2020 |
| Description | Teer coating limited |
| Organisation | Teer Coatings Ltd |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | We provide a business need for potentially using the equipment, expertise and technology of Teer coatings limited. |
| Collaborator Contribution | Teer coating offered some trials to develop novel surface coatings for bonding. |
| Impact | Currently planning various experimental trials. |
| Start Year | 2022 |
| Description | IMAPS-UK presence and engagement |
| Form Of Engagement Activity | A magazine, newsletter or online publication |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Industry/Business |
| Results and Impact | IMPAS-UK 2020 February newsletter reported our current research activities which can be connected to this work. |
| Year(s) Of Engagement Activity | 2018,2019,2020 |
| Description | Industrial demonstrations |
| Form Of Engagement Activity | A formal working group, expert panel or dialogue |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Industry/Business |
| Results and Impact | Working directly with project partners to demonstrate the uses of the technology using the benchmark components and materials. |
| Year(s) Of Engagement Activity | 2018 |
| Description | Project Kick off meeting |
| Form Of Engagement Activity | A formal working group, expert panel or dialogue |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Industry/Business |
| Results and Impact | Kick off meeting to advertise the grant funding and help establish the collaboration. The process of signing confidentiality and collaboratory agreements was begun. |
| Year(s) Of Engagement Activity | 2018 |
| Description | Public Engagement Talk in Theatre (Nine Lessons and Carols for Curious People) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Public/other audiences |
| Results and Impact | Nine short presentations on Science interspersed with comedians to a sell out audience of 400 people at Contact Theatre on a Friday night (compered by Robin Ince) |
| Year(s) Of Engagement Activity | 2023 |
| URL | https://contactmcr.com/events/nine-lessons-and-carols-for-curious-people |
| Description | Speaker at Chemistry in Action Schools Conference |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Schools |
| Results and Impact | 1 hour interactive talk on Materials Characterisation with electron diffraction |
| Year(s) Of Engagement Activity | 2023 |
| URL | https://educationinaction.org.uk/study-day/chemistry-in-action-13-11-2023/ |
| Description | Talk at Discover Materials Open day |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Schools |
| Results and Impact | Talk as part of the Discover Materials open day - generated lively discussion and follow up enquiries "As part of our Discover Materials Open Week Professor Sarah Haigh (University of Manchester) gave this very interesting talk about microscopy, which a very important are in Materials Science and Engineering, and how we can actually see atoms!" |
| Year(s) Of Engagement Activity | 2020 |
| URL | https://www.youtube.com/watch?v=5-EZzR-y2-E |