Topology optimization for near-junction thermal spreading of electronics in ballistic-diffusive regime

Zheng-Lai Tang; Yang Shen; Han-Ling Li; Bing-Yang Cao

doi:10.1016/j.isci.2023.107179

Topology optimization for near-junction thermal spreading of electronics in ballistic-diffusive regime

iScience. 2023 Jun 23;26(7):107179. doi: 10.1016/j.isci.2023.107179. eCollection 2023 Jul 21.

Authors

Zheng-Lai Tang¹, Yang Shen¹, Han-Ling Li¹, Bing-Yang Cao¹

Affiliation

¹ Key Laboratory of Thermal Science and Power Engineering of Education of Ministry, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China.

Abstract

Hotspots in electronic devices can cause overheating and reduce performance. Enhancing the thermal spreading ability is critical for reducing device temperature to improve the reliability. However, as devices shrink, phonon ballistic effects can increase thermal resistance, making conventional optimization methods less effective. This paper presents a topology optimization method that combines the phonon Boltzmann transport equation with solid isotropic material with penalization method to optimize high thermal conductivity (HTC) material distributions for thermal spreading problems. Results show that the contraction-expansion structure can effectively reduce thermal resistance. Optimal distributions differ from that based on Fourier's heat conduction law, and only the trunk structure appears in optimized layouts due to the size effect. Additionally, HTC material with longer mean free paths tends to be filled around the heat source with a gap in a ballistic-diffusive regime. This work deepens understanding of thermal spreading and aids in thermal optimization of microelectronic chips.

Keywords: Computational materials science; Electronic materials; Materials science; Modeling in materials science; Thermal engineering.