Page 17 - ASME InterPACK 2017 Program

Technology Talks

TRACK 1: HETEROGENEOUS INTEGRATION; MICROSYSTEMS
WITH DIVERSE FUNCTIONALITY

FRIDAY, SEPTEMBER 01, 2017 7:30 am – 9:00 am
Washington, Second Floor

Dr. Ravi Prasher 8-1-1 - Enhancing Thermal Transport at Material Interfaces

Lawrence Berkeley Session Organizer: Prof. Samuel Graham, Georgia Institute of Technology
National Laboratory Session Co-Organizer: Dr. Kaushik Mysore, AMD

Thermal interfaces play a significant role in electronic devices, especially those that operate
under high power densities. This paradigm is of special interest to wide bandgap devices under
development for future power electronics and rf devices for 5G and communication systems.
Recently, methods to control the thermal boundary resistance between materials in electronic
systems have shown great promise, allowing improved thermal control of electronics during
operation. This Technology Talk will cover the fundamentals of thermal interfaces in electronic
devices from phonon transport through practical limitations due to device material composition
and architecture. Applications to a range of emerging semiconductor technologies will be
discussed.

Ravi Prasher is the Division Director of Energy Storage and Distributed Resources division at
LBNL. Ravi joined LBNL in June 2015. Prior to joining LBNL, Ravi was the VP of product
development of Sheetak Inc., a startup developing solid state thermoelectric energy converters
and was a former program manager at ARPA-E. Prior to joining ARPA-E, Ravi was the technology
development manager of thermal management group at Intel. Ravi has published more 85
archival journal papers and holds more than 30 patents. He is a fellow of ASME and a senior
member of IEEE. He was the recipient of Intel achievement award (highest award for technical
achievement in Intel). He is also a recipient of outstanding young engineer award from
components and packaging society of IEEE. Ravi obtained his B.Tech. from IIT Delhi and Ph.D.
from Arizona State University.

Professor Manipulating Interfacial Thermal Transport Using Surface Chemistry
Patrick E. Hopkins
Thermal interfaces play a significant role in variety of technologies such as microelectronics,
University of Li-Ion batteries, and thermal insulation of buildings. In many applications such as microelectron-
Virginia ics large interfacial conductance is desired whereas in some applications very low interfacial
conductance is desired. Thermal interface conductance can be tuned by orders of magnitude
by manipulating phonon transmissivity. Surface chemistry can either make the interfacial bond 17
strength very weak (van der Waals) or very strong (covalent) leading to significant changes in
phonon transmissivity.

Patrick E. Hopkins is an Associate Professor in the Department of Mechanical and Aerospace
Engineering at the University of Virginia. Patrick’s current research interest are in energy
transport, charge flow, laser-chemical processes and photonic interactions with condensed
matter, soft materials, liquids, vapors and their interfaces. Patrick’s group at the University of
Virginia uses various optical thermometry-based experiments to measure the thermal conduc-
tivity, thermal boundary conductance, thermal accommodation, strain propagation and sound
speed, and electron, phonon, and vibrational scattering mechanisms in a wide array of bulk
materials and nanosystems. Patrick has authored over 140 technical papers (peer reviewed) and
been awarded 3 patents. Patrick is the recipient of an Air Force Office of Scientific Research
Young Investigator Award, an Office of Naval Research Young Investigator Award, the ASME
Bergles-Rohsenow Young Investigator Award in Heat Transfer, and the Presidential Early Career
Award for Scientists and Engineering.