IEC TS 62607-2-6:2024

Nanomanufacturing - Key control characteristics - Part 2-6: Carbon nanotube-related products - Thermal diffusivity of vertically-aligned carbon nanotubes: flash method

IEC TS 62607-2-6:2024 which is a technical specification, specifies a protocol for determining the key control characteristic
- thermal diffusivity
for vertically-aligned carbon nanotube (VACNT) films grown on solid substrates by
- flash method.
A light pulse from a flash lamp or a laser is irradiated onto the front surface (substrate side) of the VACNT film on solid substrates. Then, the temperature change of the other side of the specimen is monitored in real time after the pulse irradiation. The thermal diffusivity of the VACNT film can be analysed from the time variation of this temperature change.
- This method is applicable for evaluating the thermal transport properties of the VACNT films that can be used as thermal interface materials in electronics assembly.

General Information

• Status: Published
• Publication Date: 06-Aug-2024
• ICS: 07.120 - Nanotechnologies
• Technical Committee: TC 113 - Nanotechnology for electrotechnical products and systems
• Drafting Committee: WG 8 - TC 113/WG 8
• Current Stage: PPUB - Publication issued
• Start Date: 16-Aug-2024
• Completion Date: 07-Aug-2024

Standards Content (Sample)

IEC TS 62607-2-6 ®
Edition 1.0 2024-08
TECHNICAL
SPECIFICATION
colour
inside
Nanomanufacturing – Key control characteristics –
Part 2-6: Carbon nanotube-related products – Thermal diffusivity of vertically-
aligned carbon nanotubes: flash method

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IEC TS 62607-2-6 ®
Edition 1.0 2024-08
TECHNICAL
SPECIFICATION
colour
inside
Nanomanufacturing – Key control characteristics –

Part 2-6: Carbon nanotube-related products – Thermal diffusivity of vertically-

aligned carbon nanotubes: flash method

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 07.120  ISBN 978-2-8322-9455-0

– 2 – IEC TS 62607-2-6:2024 © IEC 2024
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and abbreviated terms . 6
3.1 Terms and definitions . 7
3.2 Abbreviated terms . 8
4 Measurement of thermal diffusivity of vertically-aligned carbon nanotubes on solid
substrates with flash method . 8
4.1 General . 8
4.2 Measurement principle . 9
4.3 Thickness and mass density measurement for VACNT film . 10
4.4 Coating substrate surface . 10
4.5 Incident light pulse . 10
4.6 Temperature measurement at the rear surface of sample . 10
4.7 Measurement environment . 11
5 Data analysis . 11
5.1 Bilayer analytical model . 11
5.2 Evaluation of thermal diffusivity of VACNT film . 11
6 Reporting. 11
Annex A (informative) Case study of thermal diffusivity measurements for vertically-
aligned carbon nanotubes grown on Si substrates . 13
A.1 General . 13
A.2 Sample preparation for VACNTs . 13
A.3 Result of flash measurements for VACNT samples . 14
A.4 Analytical solution of transient temperature rise for bilayer sample measured
with flash method . 17
Annex B (informative) Estimating thermal conductivity values of VACNTs . 18
Bibliography . 19

Figure 1 – Schematic diagram of flash method for VACNT film on substrate . 9
Figure 2 – Typical transient temperature curve for VACNT film on substrate . 9
Figure A.1 – Cross-sectional scanning electron microscope images of vertically-aligned
carbon nanotube films on Si substrates. 14
Figure A.2 – Normalized transient temperature curves measured for vertically-aligned
carbon nanotube films on Si substrates. 16

Table 1 – Example table format for reporting . 12
Table A.1 – Physical parameters obtained from VACNT samples . 17

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
NANOMANUFACTURING –
KEY CONTROL CHARACTERISTICS –
Part 2-6: Carbon nanotube-related products –
Thermal diffusivity of vertically-aligned carbon nanotubes: flash method

FOREWORD
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IEC TS 62607-2-6 has been prepared by IEC technical committee 113: Nanotechnology for
electrotechnical products and systems. It is a Technical Specification.
The text of this Technical Specification is based on the following documents:
Draft Report on voting
113/823/DTS 113/845/RVDTS
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
– 4 – IEC TS 62607-2-6:2024 © IEC 2024
The language used for the development of this Technical Specification is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 62607 series, published under the general title Nanomanufacturing
– Key control characteristics, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
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• reconfirmed,
• withdrawn, or
• revised.
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INTRODUCTION
Vertically-aligned carbon nanotubes (VACNTs) possess array structures, in which nanotubes
are oriented in the perpendicular direction to a substrate surface. Chemical vapour deposition
(CVD) is one of the common methods for the synthesis of VACNTs, where CNTs can be grown
in the presence of metal catalysts, via thermal decomposition of hydrocarbon sources such as
methane, ethylene, acetylene, ethanol, and so on. VACNTs are promising as thermal interface
materials in electronics assembly owing to their high thermal conductivity, desirable mechanical
properties, and good stability. Thermal transport properties in VACNT films really depend on
their distribution and alignment behaviours of individual nanotubes, disorders such as defects
and impurities.
Thermal diffusivity is one of the key parameters that govern thermal transport properties in solid
materials. Flash method is a well-established, standard technique for measuring the thermal
diffusivity. Originally, flash method was applicable to homogeneous monolithic (single layer)
samples. In fact, some previous works reported thermal diffusivity measurements for self-
standing VACNTs that were peeled off from the substrates after the CNT growth. However,
VACNT films will be tightly connected to solid substrates in possible practical applications such
as thermal interface materials. This means that flash method can not be simply appl
...