Investigations on heat flow management perspective-induced design criteria of thermal interface materials

Thermal interface materials (TIMs) are a critical component of thermal management systems, with efforts being made to improve their thermal conductivity (k) to enhance their thermal-management performance in electronic devices. However, the heat flow management ability should be the key factor for determining thermal-management performance, instead of the k of the TIMs alone as commonly assumed. Systematically looking for what factors will affect the heat flow management ability and understanding how they can influence the thermal-management performance is urgent. In this work, we combined both experiments and simulations to clarify this issue in a TIM-based thermal management system. The heat flow management ability of TIMs was classified into two categories based on the heat flow directions: the heat transport ability, responsible for transferring heat from the chip to heat sink in through-plane direction; and the heat flow dispersion ability, pertaining to the in-plane dispersion of heat flow within the chip. These two kinds of ability of TIMs were found to be affected by different properties beyond just k: the former was proportional to the thermal resistance of TIMs and the contact area between TIMs and chips, while the latter was influenced by the area and anisotropic k of TIMs. Through systematic analysis of heat flow, a clear understanding of the heat flow management ability was obtained, leading to the proposal of design criteria grounded in the perspective of heat flow management. These criteria aim to guide the development of efficient materials design and further enhance thermal-management performance. (c) 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).