Realizing the nanoscale quantitative thermal mapping of scanning thermal microscopy by resilient tip–surface contact resistance models

2018 ◽  
Vol 3 (5) ◽  
pp. 505-516 ◽  
Author(s):  
Yifan Li ◽  
Nitin Mehra ◽  
Tuo Ji ◽  
Jiahua Zhu
Keyword(s):  
Thermal Properties ◽  
Contact Resistance ◽  
Quantitative Assessment ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Scanning Thermal Microscopy ◽  
Thermal Microscopy ◽  
Substrate Interface ◽  
Surface Contact ◽  
Surface Contact Resistance

Quantitative assessment of thermal properties by scanning thermal microscopy (SThM) is a demanded technology, but still not yet available due to the presence of unpredictable thermal contact resistance (TCR) at the tip/substrate interface.

scholarly journals Scanning Thermal Microscopy of Ultrathin Films: Numerical Studies Regarding Cantilever Displacement, Thermal Contact Areas, Heat Fluxes, and Heat Distribution

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 491
Author(s):  
Christoph Metzke ◽  
Fabian Kühnel ◽  
Jonas Weber ◽  
Günther Benstetter
Keyword(s):  
Thermal Properties ◽  
Ultrathin Films ◽  
Hexagonal Boron Nitride ◽  
Thermal Contact ◽  
Heat Transfer Process ◽  
Heat Propagation ◽  
Heat Fluxes ◽  
Detailed Knowledge ◽  
Scanning Thermal Microscopy ◽  
Thermal Microscopy

New micro- and nanoscale devices require electrically isolating materials with specific thermal properties. One option to characterize these thermal properties is the atomic force microscopy (AFM)-based scanning thermal microscopy (SThM) technique. It enables qualitative mapping of local thermal conductivities of ultrathin films. To fully understand and correctly interpret the results of practical SThM measurements, it is essential to have detailed knowledge about the heat transfer process between the probe and the sample. However, little can be found in the literature so far. Therefore, this work focuses on theoretical SThM studies of ultrathin films with anisotropic thermal properties such as hexagonal boron nitride (h-BN) and compares the results with a bulk silicon (Si) sample. Energy fluxes from the probe to the sample between 0.6 µW and 126.8 µW are found for different cases with a tip radius of approximately 300 nm. A present thermal interface resistance (TIR) between bulk Si and ultrathin h-BN on top can fully suppress a further heat penetration. The time until heat propagation within the sample is stationary is found to be below 1 µs, which may justify higher tip velocities in practical SThM investigations of up to 20 µms−1. It is also demonstrated that there is almost no influence of convection and radiation, whereas a possible TIR between probe and sample must be considered.

scholarly journals Thermal contact resistance across a linear heterojunction within a hybrid graphene/hexagonal boron nitride sheet

2016 ◽  
Vol 18 (35) ◽  
pp. 24164-24170 ◽  
Author(s):  
Yang Hong ◽  
Jingchao Zhang ◽  
Xiao Cheng Zeng
Keyword(s):  
Heat Transfer ◽  
Thermal Properties ◽  
Boron Nitride ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Hexagonal Boron Nitride ◽  
Thermal Contact ◽  
Thermal Conductance ◽  
Vital Role ◽  
Interfacial Thermal Conductance

Interfacial thermal conductance plays a vital role in defining the thermal properties of nanostructured materials in which heat transfer is predominantly phonon mediated.

Numerical Determination of Thermal Contact Resistance for Nonisothermal Forging Processes

2000 ◽  
Vol 122 (4) ◽  
pp. 776-784 ◽  
Author(s):  
A.-S. Marchand ◽  
M. Raynaud
Keyword(s):  
Thermal Properties ◽  
Finite Difference Method ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Numerical Study ◽  
Thermal Contact ◽  
Numerical Determination ◽  
Predictive Capability ◽  
Interface Geometry

A numerical study is conducted to estimate the thermal contact resistance (TCR) between the tool and the workpiece during slow nonisothermal forging processes. A finite difference method is used to determine the TCR from a thermomechanical microscopic model. Correlations of the numerical results are developed for the TCR as a function of the interface geometry and the thermal properties. The method used to introduce these correlations in forging softwares, to account for a time and space-dependent TCR instead of a constant arbitrary value, is given. The predictive capability of the correlations is partially validated by comparing their outputs with TCR results from the literature. [S0022-1481(00)00903-8]

Three-Dimensional Thermal Model of Resistance Spot Welding in Aluminum

1999 ◽  
Author(s):  
A. A. S. Arefin Kabir ◽  
Jamil A. Khan ◽  
Kirk Broach
Keyword(s):  
Contact Resistance ◽  
Phase Change ◽  
Weld Pool ◽  
Thermal Contact ◽  
Thermal Contact Conductance ◽  
Work Piece ◽  
Contact Conductance ◽  
Faying Surface ◽  
Surface Contact ◽  
Surface Contact Resistance

Abstract A 3-D thermal model for resistance spot welding in aluminum is presented. The numerical model, validated with experimental findings, considers phase change and the associated weld-pool convection. A parametric study is performed to determine the influence of welding features such as faying surface (work-piece contact surface) contact resistance, current, electrode-work-piece surface-thermal-contact-conductance and electrode tip diameter. These parameters have significant effects on the nugget and heat-affected-zone geometry. The phase change morphology, including melting and solidification rates and weld pool dynamics, is also significantly influenced by the parameters studied. The strongest convection was observed at the center of the molten pool in a plane aligned with gravity. Although two prominent convection cells develop, the phase change morphology is not significantly affected due to the short welding time (less than 0.05 seconds) and low fluid velocity (smaller than 1 × 10−2 mm/s). The nugget grows nonlinearly with increasing current and faying surface contact resistance while diminishing with increasing electrode work-piece surface-thermal-contact-conductance. The influence of faying surface contact resistance on nugget size is less than that of the other parameters. Optimum selection of electrode tip diameter provides the best possible nugget. The duration of weld pool existence increases with the increasing current but decreases with the increasing electrode work-piece surface-thermal-contact-conductance.

Thermal Conductivity and Contact Resistance Measurements for Adhesives

2007 ◽  
Author(s):  
Peter Teertstra
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Bulk Material ◽  
Thermal Contact ◽  
Filler Materials ◽  
Bonded Joint ◽  
Linear Fit ◽  
Selection Of

Thermal adhesives that contain large concentrations of high thermal conductivity filler materials, such as ceramics or metals, are widely used by the electronics industries in a variety of applications. The thermal properties of these materials, such as the thermal contact resistance across a bonded joint and the thermal conductivity of the bulk material, are critical to the selection of the “best” material. A method is presented for the measurement of these thermal properties using a steady-state, guarded heat flux meter test apparatus based on the well-documented and familiar ASTM test standard D-5470. Five different adhesive materials are tested and a linear fit of the resulting resistance versus thickness data are used to determine the bulk thermal conductivity and contact resistance values. Four of the five materials tested had conductivity values of less than 1 W/mK, and the data demonstrates that a small but significant thermal contact resistance exists between the adhesive and the substrate for each of the adhesives.

Sign in / Sign up

Export Citation Format

Share Document