Control of Nanoplane Orientation in voBN for High Thermal Anisotropy in a Dielectric Thin Film: A New Solution for Thermal Hotspot Mitigation in Electronics
Artikel i vetenskaplig tidskrift, 2017

High anisotropic thermal materials, which allow heat to dissipate in a preferential direction, are of interest as a prospective material for electronics as an effective thermal management solution for hot spots. However, due to their preferential heat propagation in the in-plane direction, the heat spreads laterally instead of vertically. This limitation makes these materials ineffective as the density of hot spots increases. Here, we produce a new dielectric thin film material at room temperature, named vertically ordered nanocrystalline h-BN (voBN). It is produced such that its preferential thermally conductive direction is aligned in the vertical axis, which facilitates direct thermal extraction, thereby addressing the increasing challenge of thermal crosstalk. The uniqueness of voBN comes from its h-BN nanocrystals where all their basal planes are aligned in the direction normal to the substrate plane. Using the 3 omega method, we show that voBN exhibits high anisotropic thermal conductivity (TC) with a 16-fold difference between through-film TC and in-plane TC (respectively 4.26 and 0.26 W.m(-1).K-1). Molecular dynamics simulations also concurred with the experimental data, showing that the origin of this anisotropic behavior is due to the nature of voBN's plane ordering. While the consistent vertical ordering provides an uninterrupted and preferred propagation path for phonons in the through-film direction, discontinuity in the lateral direction leads to a reduced in-plane TC. In addition, we also use COMSOL to simulate how the dielectric and thermal properties of voBN enable an increase in hot spot density up to 295% compared with SiO2, without any temperature increase.

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Thermal conductivity

pulsed-laser deposition

COMSOL

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science

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thermoelectric

3 omega

Materials Science

conductivity

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1995

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properties

diffusivity

Molecular dynamics

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boron-nitride nanotubes

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polyimide films

Science & Technology - Other Topics

journal of heat transfer-transactions of the asme

physical review

p325

v116

Boron nitride

Författare

O. Cometto

Nanyang Technological University

Kabir Majid Samani

Elektronikmaterial och system

B. Liu

Nanyang Environment and Water Research Institute

S. Sun

Chalmers University of Technology

S. H. Tsang

Nanyang Technological University

Johan Liu

Elektronikmaterial och system

Chalmers, Mikroteknologi och nanovetenskap (MC2), Fotonik

K. Zhou

Nanyang Technological University

E. H. T. Teo

Nanyang Technological University

ACS Applied Materials & Interfaces

1944-8244 (ISSN) 1944-8252 (eISSN)

Vol. 9 7456-7464

Styrkeområden

Nanovetenskap och nanoteknik

Ämneskategorier

Data- och informationsvetenskap

DOI

10.1021/acsami.6b15014