IEC 61189-2-801:2023

IEC 61189-2-801
®

Edition 1.0 2023-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside


Test methods for electrical materials, printed boards and other interconnection
structures and assemblies –
Part 2-801: Thermal conductivity test for base materials

Méthodes d’essai pour les matériaux électriques, les cartes imprimées et autres
structures d’interconnexion et ensembles –
Partie 2-801: Essai de conductivité thermique pour matériaux de base
IEC 61189-2-801:2023-07(en-fr)

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IEC 61189-2-801

®


Edition 1.0 2023-07




INTERNATIONAL



STANDARD




NORME


INTERNATIONALE
colour

inside










Test methods for electrical materials, printed boards and other interconnection

structures and assemblies –

Part 2-801: Thermal conductivity test for base materials



Méthodes d’essai pour les matériaux électriques, les cartes imprimées et autres

structures d’interconnexion et ensembles –


Partie 2-801: Essai de conductivité thermique pour matériaux de base












INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE





ICS 31.180  ISBN 978-2-8322-7258-9




Warning! Make sure that you obtained this publication from an authorized distributor.

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® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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– 2 – IEC 61189-2-801:2023 © IEC 2023
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Applicability and use of data . 5
5 Test specimens . 5
5.1 Number . 5
5.2 Form . 5
5.3 Preparation of the test specimen . 6
6 Materials and equipment. 8
7 Procedure . 9
7.1 Pre-conditioning . 9
7.2 Test conditions . 9
7.3 Equipment set-up . 9
7.4 Equipment calibration . 9
7.5 Test method . 10
8 Calculations . 10
9 Report . 10
Bibliography . 11

Figure 1 – Specimen dimensions . 6
Figure 2 – Location of 0,55 mm hole . 6
Figure 3 – Example of carbon ink deposited on a screen prior to printing . 7
Figure 4 – Specimen after first screen printing . 7
Figure 5 – Finished specimen . 8
Figure 6 – Set-up of the sensor calibration . 10

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IEC 61189-2-801:2023 © IEC 2023 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

TEST METHODS FOR ELECTRICAL MATERIALS, PRINTED BOARDS AND
OTHER INTERCONNECTION STRUCTURES AND ASSEMBLIES –

Part 2-801: Thermal conductivity test for base materials

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
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rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 61189-2-801 has been prepared by IEC technical committee TC 91: Electronics assembly
technology. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
91/1757/CDV 91/1862/RVC

Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.

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– 4 – IEC 61189-2-801:2023 © IEC 2023
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/standardsdev/publications.
A list of all parts in the IEC 61189 series, published under the general title Test methods for
electrical materials, printed boards and other interconnection structures and assemblies, 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
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

IMPORTANT – The "colour inside" logo on the cover page of this document indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

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IEC 61189-2-801:2023 © IEC 2023 – 5 –
TEST METHODS FOR ELECTRICAL MATERIALS, PRINTED BOARDS AND
OTHER INTERCONNECTION STRUCTURES AND ASSEMBLIES –

Part 2-801: Thermal conductivity test for base materials



1 Scope
This part of IEC 61189 defines a test method to be followed for thermal performance via carbon
ink heating. The method employs a screened-on pattern of carbon ink used to determine the
thermal performance of a dielectric layer on a metal base plate.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
4 Applicability and use of data
This method may be used on any smooth, rigid metal clad laminate providing that the metal
base has a thickness of 1,02 mm. The best results are achieved by using a machinable,
1,57 mm thick piece of aluminium alloy. Soft metal or metal with a rough surface is not suitable
for this test method.
5 Test specimens
5.1 Number
Five specimens shall be prepared, unless an alternative number has been specified.
5.2 Form
Specimens shall be 25,4 mm × 25,4 mm and have dielectric applied to a single side of the
1,57 mm metal base. Specimens shall include 2 strips of copper that measure 2,5 mm × 20 mm,
with a 5 mm spacing between the two. See Figure 1 for the required specimen dimensions.

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– 6 – IEC 61189-2-801:2023 © IEC 2023
Dimensions in millimetres

Figure 1 – Specimen dimensions
A centralised hole shall be drilled in the 1,57 mm aluminium substrate. The location of the hole
shall be such that it is equidistant between the two copper electrodes and terminates at the
midpoint, as demonstrated in Figure 2.
Dimensions in millimetres

Figure 2 – Location of 0,55 mm hole
5.3 Preparation of the test specimen
a) Deposit a 12 mm × 5 mm rectangle of carbon ink on the dielectric surface, using a rubber
squeegee and a 195-mesh screen that has a 12 mm × 5 mm aperture. See Figure 3 for an
example of carbon paste applied to a screen prior to printing.
b) Locate the carbon ink printing such that it is perpendicular to the length of the copper
electrodes and is central to the specimen surface.
c) Ensure that the screen and specimen are secured such that there will be no movement
during the printing of the carbon ink.
d) For printing the carbon ink, apply the ink to one of the narrow edges of the rectangle and
then use the rubber squeegee to spread the paste along the length of the rectangle in the
screen, in a single motion. A small amount of downward force should be applied when
moving the squeegee from one side of the frame to the other.

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IEC 61189-2-801:2023 © IEC 2023 – 7 –

Figure 3 – Example of carbon ink deposited on a screen prior to printing
e) Bring the squeegee back in the reverse direction, still with a small amount of force being
applied, to ensure an even coating of the carbon ink is left on the surface of the sample.
f) Remove the screen from the sample with care, so as not to touch the wet ink or for any
smearing to occur. See Figure 4 for an example of how the specimen should look after the
first screen printing has been completed.

Figure 4 – Specimen after first screen printing
g) Have an oven pre-warmed to 125 °C and place the specimen(s) into it for a period of 20 min.
h) Start by using methyl ethyl ketone (MEK) to clean the mesh screen, which should then be
followed with propan-2-ol (IPA).
i) After 20 min have elapsed, remove the specimens from the oven and allow them to cool.
Once cooled to room temperature, apply a second layer of carbon ink by repeating steps d)
through h). The second layer shall be applied directly to the first layer.
j) Once the specimens have been allowed to cool, use a multimeter to measure the resistance
between the two copper electrodes.
k) Any specimen that does not have a measured resistance value of (40 ± 15) Ω shall be
discarded.
l) Prepare the hot plate by setting it to a temperature of 225 °C.
m) Deposit sufficient solder paste onto the base of two test pins. One pin should be placed onto
each copper electrode, position them at the ends that are closest to the thermocouple hole.
n) When required, excess corrosion should be removed from the copper electrodes using a
small volume of flux.
o) Using the hot plate, reflow the solder paste applied to the test pins. This is best achieved
by locating the test pins on the hottest part of the hot plate.

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– 8 – IEC 61189-2-801:2023 © IEC 2023
p) Once reflow has occurred, carefully take the specimen off the hot plate, making sure not to
disturb the test pin. The specimen should now be allowed to cool. See Figure 5 for an
example of how the completed specimen should look.

Figure 5 – Finished specimen
q) Steps j) and k) shall now be repeated.
6 Materials and equipment
a) microdrill with a 0,55 mm drill bit;
b) 195-mesh screen with a 12 mm × 5 mm aperture in a frame 101,6 mm × 101,6 mm;
c) carbon ink with a resistance of approximately 100 Ω/sq;
d) hard rubber (70 Shore A) squeegee for screen printing;
e) polyimide tape, 12,5 mm or 25,4 mm wide;
f) forced air oven;
g) methyl ethyl ketone (MEK);
h) propan-2-Ol (IPA);
i) a digital multimeter;
j) hot plate capable of achieving at least 250 °C;
k) solder paste;
l) SMD test-point pins;
m) digital acquisition system;
n) computer with DAQ software installed or equivalent;
o) microcontroller with sensor conversion software;
p) programmable power supply with USB or GPIB interface or equivalent;
q) USB or GPIB interface or equivalent;
r) thermal grease;
s) wooden tongue depressors;
t) infinite heat sink fixture with a pneumatic cylinder ram;
u) fluid heater unit;
v) thermocouple probe – type T;
w) fluid chiller unit;
x) infrared (IR) sensor and bridge with amplifying electronics;
y) black microhook connector with 2 attached wires;
z) red microhook connector with 2 attached wires;
aa) wet sander;
bb) permanent marker, black, extra-fine tip.

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IEC 61189-2-801:2023 © IEC 2023 – 9 –
7 Procedure
7.1 Pre-conditioning
Samples should be conditioned at 23 °C ± 2 °C, 50 % RH for 24 h prior to testing, where
possible, and unless otherwise specified.
7.2 Test conditions
The laboratory conditions during testing should be 23 °C ± 2 °C, 50 % RH.
7.3 Equipment set-up
a) Using the digital acquisition system, attach the thermocouple probe wire to channel 0.
b) Take the red microhook and connect one of the wires to the positive (+) output of the power
supply. The second wire should then be connected to the 0 + voltage input channel of the
digital acquisition system. Repeat the process for the black microhook connector using the
equivalent negative (−) connection points.
c) Connect the interface equipment to the controlling PC, where applicable, and the DC power
supply turned on. The power supply should be allowed to stabilise for a minimum of 30 min.
7.4 Equipment calibration
a) Start the heating unit and allow it to stabilise at 85 °C to 90 °C.
b) The microcontroller with sensor conversion software and digital acquisition system are to
be connected to the controlling PC and turned on. The digital acquisition system should now
be allowed to stabilise for 30 min.
c) Using the same sample form as defined in 5.2, remove both copper bars from the dielectric
surface and then screen print carbon ink onto the complete surface area. This will be the
calibration specimen.
d) Take one of the tongue depressors and break into half, giving two pieces that are
approximately 5 mm × 25 mm in size. Set these aside for later use.
e) Take the calibration specimen created in point c) and apply a thin layer of thermal grease
on the reverse side. Then place this sample onto the centre of the infinite heat sink plate.
f) Heat the plate and specimen to a temperature of 85 °C to 90 °C using the hot water
circulator.
g) Take the two pieces of tongue depressor from point d) and place them on the opposite edges
of the top of the calibration specimen, then place the IR sensor and bridge onto the two
pieces of the tongue depressor. Apply the pneumatic ram. See Figure 6 for an example of
the sensor calibration set up.
h) Fit the thermocouple probe into the calibration specimen and initiate the calibration
software.
i) Shut off the heater and connect the chiller plate to the cooling unit. Bring the system down
to a temperature of 30 °C to 35 °C.

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– 10 – IEC 61189-2-801:2023 © IEC 2023

Figure 6 – Set-up of the sensor calibration
7.5 Test method
a) Apply a thin layer of the thermal interface material to the reverse side of the test specimen.
Position that specimen at the centre of the infinite heat sink.
b) Locate the IR sensor and bridge onto the top of the specimen and apply the pneumatic ram.
c) Attach the microhooks to the test pins, black to one and red to the remaining one.
d) Fit the thermocouple probe into the test specimen.
e) Initiate the software and let it complete a test cycle.
8 Calculations
The software will process all the data to provide the user with the thermal performance value.
It does this by deducting the surface temperature from the thermocouple temperature and
dividing the resultant value by the power.
9 Report
The following shall be included in the report for the five specimens tested:
a) average deviation of the thermal performance;
b) standard deviation of the thermal performance;
c) identification and the description of the material tested;
d) any deviation from the test method;
e) date of the test;
f) name of the person conducting the test.

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IEC 61189-2-801:2023 © IEC 2023 – 11 –
Bibliography
IEC 62899-202, Printed electronics – Part 202: Materials – Conductive ink

___________

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– 12 – IEC 61189-2-801:2023 © IEC 2023
SOMMAIRE
AVANT-PROPOS . 13
1 Domaine d’application . 15
2 Références normatives . 15
3 Termes et définitions . 15
4 Applicabilité et utilisation des données . 15
5 Spécimens . 15
5.1 Nombre . 15
5.2 Forme . 15
5.3 Préparation des spécimens . 16
6 Matériaux et équipements . 18
7 Procédure . 19
7.1 Préconditionnement . 19
7.2 Conditions d’essai . 19
7.3 Montage des équipements . 19
7.4 Étalonnage des équipements . 19
7.5 Méthode d’essai . 20
8 Calculs . 20
9 Rapport . 20
Bibliographie . 21

Figure 1 – Dimensions des spécimens . 16
Figure 2 – Emplacement du trou de 0,55 mm . 16
Figure 3 – Exemple d’encre à base de carbone déposée sur un écran avant
l’impression . 17
Figure 4 – Spécimen après la première sérigraphie . 17
Figure 5 – Spécimen fini . 18
Figure 6 – Montage d’étalonnage du détecteur . 20

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IEC 61189-2-801:2023 © IEC 2023 – 13 –
COMMISSION ÉLECTROTECHNIQUE INTERNATIONALE
____________

MÉTHODES D’ESSAI POUR LES MATÉRIAUX ÉLECTRIQUES, LES CARTES
IMPRIMÉES ET AUTRES STRUCTURES D’INTERCONNEXION ET
ENSEMBLES –

Partie 2-801: Essai de conductivité thermique pour matériaux de base

AVANT-PROPOS
1) La Commission Electrotechnique Internationale (IEC) est une organisation mondiale de normalisation composée
de l'ensemble des comités électrotechniques nationaux (Comités nationaux de l’IEC). L’IEC a pour objet de
favoriser la coopération internationale pour toutes les questions de normalisation dans les domaines de
l'électricité et de l'électronique. À cet effet, l’IEC – entre autres activités – publie des Normes internationales,
des Spécifications techniques, des Rapports techniques, des Spécifications accessibles au public (PAS) et des
Guides (ci-après dénommés "Publication(s) de l’IEC"). Leur élaboration est confiée à des comités d'études, aux
travaux desquels tout Comité national intéressé par le sujet traité peut participer. Les organisations
internationales, gouvernementales et non gouvernementales, en liaison avec l’IEC, participent également aux
travaux. L’IEC collabore étroitement avec l
...