ASTM D5470-06

Standard Test Method for Thermal Transmission Properties of Thermally Conductive Electrical Insulation Materials

SCOPE
1.1 This standard covers a test method for measurement of thermal impedance and calculation of an apparent thermal conductivity for thermally conductive electrical insulation materials ranging from liquid compounds to hard solid materials.
1.2 The term "thermal conductivity" applies only to homogeneous materials. Thermally conductive electrical insulating materials are usually heterogeneous and to avoid confusion this test method uses "apparent thermal conductivity" for determining thermal transmission properties of both homogeneous and heterogeneous materials.
1.3 The values stated in SI units are to be regarded as standard.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Mar-2006
• ICS: 29.035.01 - Insulating materials in general
• Technical Committee: D09 - Electrical and Electronic Insulating Materials

Relations

• Replaces: ASTM D5470-01 - Standard Test Method for Thermal Transmission Properties of Thin Thermally Conductive Solid Electrical Insulation Materials
• Effective Date: 01-Apr-2006
• Replaced By: ASTM D5470-06(2011) - Standard Test Method for Thermal Transmission Properties of Thermally Conductive Electrical Insulation Materials
• Effective Date: 01-Apr-2011
• Referred By: ASTM D6343-14(2018) - Standard Test Methods for Thin Thermally Conductive Solid Materials for Electrical Insulation and Dielectric Applications
• Effective Date: 01-Apr-2006

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
An American National Standard
Designation:D5470–06
Standard Test Method for
Thermal Transmission Properties of Thermally Conductive
1
Electrical Insulation Materials
This standard is issued under the fixed designation D5470; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope* 3.1.1 apparent thermal conductivity (l), n—the time rate of
heat flow, under steady conditions, through unit area of a
1.1 This standard covers a test method for measurement of
heterogeneous material, per unit temperature gradient in the
thermal impedance and calculation of an apparent thermal
direction perpendicular to the area.
conductivity for thermally conductive electrical insulation
3.1.2 average temperature (of a surface), n—the area-
materials ranging from liquid compounds to hard solid mate-
weighted mean temperature.
rials.
3.1.3 composite, n—a material made up of distinct parts
1.2 The term “thermal conductivity” applies only to homo-
whichcontribute,eitherproportionallyorsynergistically,tothe
geneous materials. Thermally conductive electrical insulating
properties of the combination.
materialsareusuallyheterogeneousandtoavoidconfusionthis
3.1.4 homogeneous material, n—a material in which rel-
testmethoduses“apparentthermalconductivity”fordetermin-
evant properties are not a function of the position within the
ing thermal transmission properties of both homogeneous and
material.
heterogeneous materials.
3.1.5 thermal impedance (u), n—the total opposition that an
1.3 The values stated in SI units are to be regarded as
assembly (material, material interfaces) presents to the flow of
standard.
heat.
1.4 This standard does not purport to address all of the
3.1.6 thermal interfacial resistance (contact resistance),
safety concerns, if any, associated with its use. It is the
n—the temperature difference required to produce a unit of
responsibility of the user of this standard to establish appro-
heat flux at the contact planes between the specimen surfaces
priate safety and health practices and determine the applica-
and the hot and cold surfaces in contact with the specimen
bility of regulatory limitations prior to use.
under test. The symbol for contact resistance is R .
I
2. Referenced Documents 3.1.7 thermal resistivity, n—the reciprocal of thermal con-
2
ductivity. Under steady-state conditions, the temperature gra-
2.1 ASTM Standards:
dient, in the direction perpendicular to the isothermal surface
D374 Test Methods for Thickness of Solid Electrical Insu-
per unit of heat flux.
lation
3.2 Symbols Used in This Standard:
E691 Practice for Conducting an Interlaboratory Study to
3.2.1 l = apparent thermal conductivity, W/m·K.
Determine the Precision of a Test Method
2
3.2.2 A = area of a specimen, m .
E1225 Test Method for Thermal Conductivity of Solids by
3.2.3 d = thickness of specimen, m.
Means of the Guarded-Comparative-Longitudinal Heat
3.2.4 Q = time rate of heat flow, W or J/s.
Flow Technique
3.2.5 q = heat flux, or time rate of heat flow per unit area,
2
3. Terminology
W/m .
3.2.6 u = thermal impedance, temperature difference per
3.1 Definitions of Terms Specific to This Standard:
2
unit of heat flux, (K·m )/W.
1
This test method is under the jurisdiction of ASTM Committee D09 on 4. Summary of Test Method
Electrical and Electronic Insulating Materials and is the direct responsibility of
4.1 This standard is based on idealized heat conduction
Subcommittee D09.19 on Dielectric Sheet and Roll Products.
between two parallel, isothermal surfaces separated by a test
Current edition approved April 1, 2006. Published April 2006. Originally
approved in 1993. Last previous edition approved in 2001 as D5470 – 01. DOI:
specimen of uniform thickness. The thermal gradient imposed
10.1520/D5470-06.
on the specimen by the temperature difference between the two
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contacting surfaces causes the heat flow through the specimen.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
*A Summary of Changes section appears at the end of this standard.
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D5470–06
This heat flow is perpendicular to the test surfaces and is practical applications where these required uniform, parallel
uniform across the surf
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