The Hawkins Memorial Lecture

From Materials to Manufacturing: Strategies to Enable the Thermal Management of Wide Bandgap Electronics

Samuel Graham Jr., Dean of Engineering, University of Maryland

Thursday, October 6, 2022

11:30 a.m., WALC 2007

Abstract: Wide bandgap electronics are currently under development due to their potential to create some of the most advanced RF, optoelectronic and power electronics in the world. Applications include visible and UV LEDs and laser diodes, 5G communications, radar systems, and inverters and converters for electrical power systems. The growth of materials based on gallium nitride and more recently gallium oxide is expected to help create technological advancements in each of these areas. As these nitride and oxide semiconductors are being developed, there are a number of new materials, manufacturing techniques, and thermal and mechanical metrology methods that must be concurrently created to help ensure the transition of these materials to their intended applications. Key concerns are scalable methods for growing and packaging the devices, materials and architectures needed to ensure efficient thermal management, and the control of stresses to prevent device failure.

In this talk, we will discuss a range of materials and device architectures that are being developed to enable efficient heat dissipation from both GaN and Ga2O3 devices starting at the device level. We will also cover a range of thermal and stress metrology methods that we have developed to enable the measurement of temperature and stresses in the devices both under steady state and transient operation. Finally, an actively cooled power substrate that is being developed for packaging power devices will be presented. At each step, we will show how considerations for materials development, metrology techniques, and methods for scalable manufacturing are necessary to help transition these advancements to applications.

Biography: Dr. Samuel Graham is the Nariman Farvardin Professor and Dean of Engineering at the University of Maryland. Prior to joining the University of Maryland, he was a professor and chair of the Woodruff School of Mechanical Engineering at the Georgia Institute of Technology. He holds a joint appointment with the National Renewable Energy Laboratory, serves on the Emerging Technologies Technical Advisory Committee for the U.S. Department of Commerce, and the Engineering Science Research Foundation of Sandia National Laboratories. His research expertise is in the thermal characterization and reliability of wide bandgap semiconductor technologies for power electronics and advanced RF communications. In addition, his group works on strategies for energy thermal energy storage using phase change materials for build energy systems.

History of the Hawkins Lecture

This annual lecture series was established in 1984 to honor the memory of George A. Hawkins, former Dean of the Schools of Engineering. Renowned for his many contributions as a teacher, researcher, and administrator, he retained a strong commitment to heat transfer and was instrumental in establishing Purdue’s eminence in the field. The lecture provides an opportunity for a leader in heat transfer research to present topics of broad interest to the University community. This series is supported by an endowment created with gifts from the Heat Transfer Area faculty at Purdue.

George A. Hawkins was born in Denver, Colorado in 1907. He attended the Colorado School of Mines and the University of Denver before coming to Purdue where he received three degrees. Dr. Hawkins earned his Ph.D. in 1935 and began an academic career that spanned 41 years. Promoted to Professor of Mechanical Engineering in 1942, he was Dean of the Schools of Engineering from 1953 to 1967 and Vice President of Academic Affairs from 1967 until his retirement in 1971. In addition to his administrative duties, he continued with technical pursuits, writing several textbooks and more than 150 papers and articles dealing with heat transfer, thermodynamics, and other engineering areas.

For his technical, professional, and administrative contributions, he received many honors, including election as member of the National Academy of Engineering, Life Fellow of the American Society of Mechanical Engineers (ASME), Fellow of the American Institute of Chemical Engineers (AIChE), and Honorary Member of the American Society for Engineering Education (ASEE). He received the ASME/Pi Tau Sigma Gold Medal in 1940. As dean, he was instrumental in effecting major changes in engineering education throughout the U.S., and was awarded the ASEE Medal for Distinguished and Meritorious Service in 1968. He was named National President of ASEE in 1970.

One of his strongest professional commitments was to the subject of heat transfer, and he had an important influence on establishing Purdue as a world leader in this area. In the 1930s and 1940s, he was, with William McAdams on the East Coast, M. Jakob in the Midwest, and L.M.K. Boelter on the West Coast, a major force in promoting the transition of heat transfer from an engineering art to a modern form of engineering strongly based on scientific fundamentals. His early work as a pioneer of heat transfer is well-documented. His program flourished, producing many outstanding graduate students who have enjoyed successful careers in industry, academia, and government.

Following his retirement in 1971, Dr. Hawkins continued to be active until his death in 1978.

Past Speakers

2022  Samuel Graham, University of Maryland
2021  John Bischof, University of Minnesota
2021  Cristina Amon, University of Toronto
2019  Cynthia Hipwell, Texas A&M University
2018  Costas P. Grigoropoulos, University of California Berkeley
2017  Mehmet Toner, Harvard Medical School (photo)
2016  Suhas V. Patankar, University of Minnesota
2015  Kenneth E. Goodson, Stanford University
2014  Jean-Jacques Greffet, Institute Optique Palaiseau-France
2013  Jayathi Murthy, Purdue University
2012  Gang Chen, Massachusetts Institute of Technology
2011  Chung K. Law, Princeton University
2010  Arun Majumdar, U.S. Department of Energy
2009  Mamoru Ishii, School of Nuclear Engineering, Purdue University
2008  Paul Hommert, California Laboratories and Homeland Security & Defense Strategic Management Unit, Sandia National Laboratories
2007  Richard O. Buckius, National Science Foundation and University of Illinois at Urbana-Champaign
2006  Yogesh Jaluria, Rutgers University
2005  Massoud Kaviany, University of Michigan - Ann Arbor
2004  Dimos Poulikakos, ETH Zurich
2003  John H. Sununu, JHS Associates, Ltd.
2002  Kenneth R. Diller, University of Texas - Austin
2001  Martin C. Jischke, Purdue University
2000  Robert G. Watts, Tulane University
1999  Vijay K. Dhir, University of California - Los Angeles
1998  David P. DeWitt, Purdue University
1997  Boris Rubinsky, University of California - Berkeley
1996  Frank P. Incropera, Purdue University
1995  John R. Howell, University of Texas - Austin
1994  Julian Szekely, Massachusetts Institute of Technology
1993  Robert Siegel, NASA Lewis Research Center
1992  Richard C. Chu, International Business Machines Corporation
1991  R. J. Goldstein, University of Minnesota
1990  Raymond Viskanta, Purdue University
1989  Franz Mayinger, Technische Universität München
1988  Wataru Nakayama, Hitachi, Ltd.
1987  Chang-Lin Tien, University of California - Berkeley
1986  Arthur E. Bergles, Iowa State University
1985  E. M. Sparrow, University of Minnesota