Session: 14-01: Measurement Techniques and Thermophysical Properties in Micro/Nanoscale

Paper Number: 121238

121238 - Thermal Metrology for Advanced Electronics Packaging 

Abstract: 

To increase performance of electronic devices, package designs are moving to 2.5D and 3D system designs where the active components are assembled together in dense configurations. A key challenge is dissipating the heat from the devices to maintain the system at temperatures where the system will not degrade. From a heat transfer perspective, when the active components are stacked vertically, the interfaces between layers become even more crucial than in conventional packages as heat must transfer across multiple materials and interfaces out to the exterior surfaces where heat can be dissipated. Quantifying the ability to spread heat with a material is critical for both the active device layers and the packaging materials such as the lid or interposers. While numerous techniques exist for measuring the through thickness thermal conductivities of device and packaging materials and interface resistances near the surface of a sample, key thermal metrology challenges include measuring the thermal interface conductance buried within the 3D chip stacks and measuring the in-plane thermal conductivity of each layer in the electronics package.

This presentation will discuss techniques we developed to address each of these metrology challenges. Both techniques leverage periodic laser heating and thermal imaging with infrared cameras to quantify thermal properties of interest. Briefly, the in-plane thermal conductivity characterization technique is based in part on the Angstrom method and extended to analysis of thin films that have in-plane anisotropy. Specifically, the laser heats the center of the sample periodically and heat dissipates through the film. An infrared camera measures the spatially-varying top surface temperature response. Analysis with conventional data fitting approaches is supplemented with machine learning techniques that are more robust to noise in the temperature measurements. We have demonstrated the capability to measure thin films across a range of properties (from polymers to metals to graphite) and thicknesses (from tens of microns to ~2 mm thick) depending on the system configuration. The technique for measuring thermal resistance of buried interfaces has been developed to understand interface resistances in stacks of silicon chips but can be applied to other systems as well. Here, the temperatures at the top and bottom surface of the stack are measured while one side is heated periodically with a laser. Analysis of the magnitude and phase delay in the temperature response across the sample stack, combined with information about the thermophysical properties of each layer, enable extraction of the contact resistance. These techniques provide new tools for measuring properties which are critical to understanding the thermal response of advanced electronic devices.

Presenting Author: Amy Marconnet Purdue University

Presenting Author Biography: Professor Amy Marconnet is an associate professor of Mechanical Engineering and a Perry Academic Excellence Scholar at Purdue University. She received a B.S. in Mechanical Engineering from the University of Wisconsin – Madison in 2007, and an M.S. and a PhD in Mechanical Engineering at Stanford University in 2009 and 2012, respectively. Her dissertation focused on thermal phenomena in nanostructured materials. She then worked briefly as a postdoctoral associate at the Massachusetts Institute of Technology, before joining the faculty at Purdue University in August 2013. Research in the her lab intersects heat transfer, energy conversion, and materials science to enable advances in technologies where energy conversion and thermal transport are key factors in performance. Prof. Marconnet has developed an interdisciplinary research program to evaluate, understand, and control the physical mechanisms governing the multi-functional properties of materials, machines, and systems. Her work has won outstanding paper awards at ITherm 2012, InterPACK 2017, and ITherm 2019 and 2023. In 2017, she won the Woman in Engineering Award from the ASME Electronics & Photonics Packaging Division (EPPD). In 2020, she won the Bergles-Rohsenow Young Investigator Award in Heat Transfer and the Outstanding Graduate Student Mentor from the Official Mechanical Engineering Graduate Association (OMEGA) and the College of Engineering. She recently won a Humboldt Fellowship for Experienced Researchers and conducted research at Karlsruhe Institute of Technology in the 2021-22 academic year.

Authors:

Aalok Gaitonde Purdue University
Aaditya Candadai TBD
Shanmukhi Sripada Purdue Unversity
Justin Weibel Purdue University
Amy Marconnet Purdue University