Greetings! Welcome to the quarterly newsletter from the 3D Systems Packaging Research Center.
The first quarter of 2021 has been fantastic for us despite the pandemic. Our research in the areas of high-performance computing, power delivery, machine learning, automotive electronics and 5G/6G Wireless has expanded significantly. With Evatec and Facebook joining our industry consortium, our collaborators around the world has increased to more than 40. Further details on the companies and universities we work with are available at http://www.sites.gatech.edu/ien-prc/collaborators.
Several of our papers have been accepted this year to the premier conference sponsored by the IEEE Electronics and Packaging Society (EPS), namely ECTC. I look forward to meeting y’all at ECTC (virtually) later this year.
We provide below some recent research highlights.
Thermal Filler Engineering in Epoxy-Silica Composite for Efficient Heat Dissipation
Thermal management in high-performance computing and high-power electronics need to be assisted by thermally conductive and electrically insulating encapsulant materials. Typical silica filled epoxies are struggling from limited thermal conductivity (K) due to low thermal conductivity of epoxy and silica, and significant phonon scattering at their interfaces. Incorporation of additional high K materials along with high electrical resistivity such as 2-dimensional hexagonal boron nitride (hBN) into the epoxy composite is a possible solution. The hBN provides outstanding thermal and dielectric properties resulting in the increase in thermal conductivity of the epoxy, while random dispersion of the fine 2-D structure of hBN into the epoxy provides significant increase in viscosity, leading to poor processibility.
GT-PRC team led by Prof. CP Wong, has introduced high thermal conductivity materials into the interfaces between epoxy resin and silica particles to facilitate the flowability of the compound as well as thermal transport at the boundary. The team has made use of hBN to decorate silica surfaces and fabricate the hBN coated silica (BN@SiO2) particles in epoxy resins that demonstrate improved flowability using the unique hybrid filler configuration. Furthermore, the promising thermal conductivity of ~ 0.7 W/mK has been obtained using only 30 wt.% loading. This work was presented by graduate student J. Li and co-authors Y. Rem, K. Moon and C.P. Wong at the 2020 IEEE Electronic Components and Technology Conference (ECTC). Read here.
SEM picture of BN@SiO2 (left) and Comparison of viscosity and thermal conductivity of BN@SiO2 and BN/SiO2 filled epoxy.
Power Delivery for Future Microprocessors
Power delivery requirements for early microprocessors were rudimentary due to the relatively low power levels. However, several decades of exponential scaling powered by Moore’s law has greatly increased power requirements and complexity of the power delivery scheme. The steady growth in power levels and number of power rails in high performance microprocessors has increased the power delivery challenges. Integrated Voltage Regulators (IVR) have emerged as a key power delivery technology to address these challenges. A recent paper co-authored by K. Radhakrishna, M. Swaminathan and B. Bhattacharyya published in the IEEE Transactions on Components, Packaging and Manufacturing Technology (CPMT) provides a detailed landscape on power delivery schemes used in the past, present, and projections for the future. The paper covers advanced packaging technologies being developed and required to enable heterogeneous integration and their impact on power delivery. Read here.
Power Delivery Schemes used in various heterogeneous integration architectures (present & future)
Flex on Glass receives Award
Flexible electronics has seen rapid development in recent years. Unlike Kapton polyimide and polyethylene terephthalate (PET), glass substrates have significantly lower loss. In the paper titled “Flexible and Ultra-Thin 30 μm Glass Substrates for RF and mmWave Flex Applications”, co-authored by S. Sivapurapu, R. Chen, M. Rehman, K. Kanno, T. Kakutani, M. Letz, F. Liu, S. K. Sitaraman, and M. Swaminathan, presented at the 2021 annual flex conference, the electrical performance of ultra-thin glass stack-up with 15 μm build-up dielectric on each side is characterized up to 110 GHz. In addition, mechanical tests using Free Arc Bending show the effectiveness of glass as a candidate for high frequency flexible applications. GT-PRC Ph.D. Student Sridhar Sivapurapu received the Innovators of the Future third place award for this work. Sridhar’s video presentation is available for viewing by clicking here and then clicking on the link to SEMI blog post about all student poster award winner.
Machine Learning work Recognized
Dr. Hakki M. Torun, a GT-PRC Ph.D. student was selected for the 2021 Georgia Tech Sigma Xi Chapter Best Ph.D. Thesis Award! He was one of ten students given this prestigious award this year. Hakki’s thesis is titled “Machine Learning Based Design and Optimization for High Performance Semiconductor Packaging and Systems“. Hakki started work as a Power Integrity Engineer at Apple in San Diego, USA earlier this year.
Asif Khan has been named as a recipient of the NSF CAREER Award. He is an assistant professor in the Georgia Tech School of Electrical and Computer Engineering (ECE) and also holds a courtesy appointment in the School of Materials Science and Engineering. The title of Khan’s award is “Antiferroelectric Negative Capacitance Transistors for Ultra-low Power Computing,” and it will start on March 15, 2021 and end on February 28, 2026. Khan joined the ECE faculty in 2017. His research is on advanced semiconductor devices—devices that will shape the future of computing in the post-scaling era. His research group currently focuses on ferroelectric devices, in all aspects ranging from materials physics, growth, and electron microscopy to device fabrication, all the way to ferroelectric circuits and systems for artificial intelligence/machine learning/data-centric applications.
Sridhar Sivapurapu received his B.S. degree in Electrical Engineering from the Georgia Institute of Technology, Atlanta, GA, USA, in 2015. In 2017, he joined C3PS (Center for Co-Design of Chip, Package, and System), which has since merged into the Georgia Tech 3D Systems Packaging Research Center. His research focus areas include flexible hybrid electronics, RF electronics, and machine learning.
Congratulations to Siddharth Ravichandran on receiving the ECE Graduate Research Assistant Excellence Award. Siddharth received this award for his outstanding accomplishments as a GRA with Profs. Swaminathan and Tummala. Siddharth’s accomplishment will be recognized as part of the 2021 Roger P. Webb Awards Program in the School of Electrical and Computer Engineering.
Congratulations to Bo Song on winning the 2021 Society Outstanding Young Engineer award presented by The Electronics Packaging Society (EPS) of IEEE. He is currently a MEMS Packaging engineer at HP Inc. Prior to joining HP in 2018, he was a graduate research assistant working in Prof. C.P. Wong’s group at GT-PRC. His research areas include synthesis of functional carbon nanomaterials, development of electrically conducive composites, sealants, epoxy molding compounds, photo-patternable polymers, thin film coatings, materials design for wearable electronics, and fabrication of microscale energy storage devices.
Congratulations to our recent Graduates!
Majid Ahadi Dolatsara, Ph.D.
Thesis: High-speed channel analysis and design using polynomial chaos theory and machine learning
Employer: Keysight (CA)
Upcoming and Recent Events (All Virtual)
- Short Course – Fanout and Embedded Packages: Recent Advances and Future Trends presented by Siddharth Ravichandran on February 26, 2021. Recording
- iNEMI 5G Webinar Series: Packaging for mmWave Communications presented by Professor Madhavan Swaminathan on March 11, 2021. Recording
- Distinguished Lecture – The title is, “Flexible Hybrid Electronics 2.0”, presented by Professor Subramanian Iyer on March 25, 2021 at 12:30 PM EST. Registration is required and can be done at this link.
- Short Course – April 30, 2021 at 11:00 AM EST presented by Omkar Gupte. The title is, “Board Level Interconnections: Materials, Processes and Recent Advances”. Registration is required. Additional details will be forthcoming at the end of March.
- Spring 2021 Industry Advisory Board (IAB) Meeting on May 25 – 27, 2021. – Will take place virtually and by invitation only. Additional details will be forthcoming.