Control of Nanoplane Orientation in voBN for High Thermal Anisotropy in a Dielectric Thin Film: A New Solution for Thermal Hotspot Mitigation in Electronics
Journal article, 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.



3 omega

physical review


ick r

journal of heat transfer-transactions of the asme

polyimide films



Boron nitride



en g



pulsed-laser deposition



boron-nitride nanotubes



Materials Science

Molecular dynamics

opra ng

Thermal conductivity



Science & Technology - Other Topics



O. Cometto

Nanyang Technological University

Majid Kabiri Samani

Chalmers, Microtechnology and Nanoscience (MC2), Electronics Material and Systems

B. Liu

Nanyang Environment and Water Research Institute

S. Sun

Chalmers, Microtechnology and Nanoscience (MC2), Electronics Material and Systems

S. H. Tsang

Nanyang Technological University

Johan Liu

Chalmers, Microtechnology and Nanoscience (MC2), Electronics Material and Systems

Chalmers, Microtechnology and Nanoscience (MC2), Photonics

K. Zhou

Nanyang Technological University

E. H. T. Teo

Nanyang Technological University

ACS Applied Materials & Interfaces

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

Vol. 9 8 7456-7464

Areas of Advance

Nanoscience and Nanotechnology

Subject Categories

Computer and Information Science



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