IEC TR 61189-3-914:2017

Test methods for electrical materials, printed boards and other interconnection structures and assemblies - Part 3-914: Test method for thermal conductivity of printed circuit boards for high-brightness LEDs - Guidelines

IEC TR 61189-3-914:2017(E) specifies the detailed procedures and precautions for IEC 61189-3-913.

General Information

• Status: Published
• Publication Date: 16-Mar-2017
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 11.040.50 - Radiographic equipment
• ICS: 31.180 - Printed circuits and boards
• Technical Committee: TC 91 - Electronics assembly technology
• Drafting Committee: WG 10 - TC 91/WG 10
• Current Stage: PPUB - Publication issued
• Start Date: 03-Apr-2017
• Completion Date: 17-Mar-2017

Standards Content (Sample)

IEC TR 61189-3-914 ®
Edition 1.0 2017-03
TECHNICAL
REPORT
colour
inside
Test methods for electrical materials, printed boards and other interconnection
structures and assemblies –
Part 3-914: Test method for thermal conductivity of printed circuit boards for
high-brightness LEDs – Guidelines

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IEC TR 61189-3-914 ®
Edition 1.0 2017-03
TECHNICAL
REPORT
colour
inside
Test methods for electrical materials, printed boards and other interconnection

structures and assemblies –
Part 3-914: Test method for thermal conductivity of printed circuit boards for

high-brightness LEDs – Guidelines

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.180 ISBN 978-2-8322-4110-3

– 2 – IEC TR 61189-3-914:2017 © IEC 2017
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Test condition . 7
4.1 Standard condition . 7
4.2 Specified condition . 8
5 Pre-condition . 8
6 Heat dissipation characteristics . 8
6.1 General . 8
6.2 Measurement of thermal resistance on the plane . 9
6.3 Thermal resistance across the thickness . 12
6.4 Thermal resistance measurement procedures and precautions . 14
6.4.1 General . 14
6.4.2 Die attach . 14
6.4.3 Wire bonding . 14
6.4.4 Temperature measuring sensor (calibration) . 14
6.4.5 Measurement of thermal resistance on the plane . 14
6.4.6 Thermal resistance across the thickness using cold plate . 16
Annex A (informative) Classification and class of the PCB . 19
Annex B (informative) Measurement comparison between companies (plane) . 22

Figure 1 – Example of PCB with large thermal conductivity . 9
Figure 2 – Examples of PCBs with large heat transfer coefficients . 9
Figure 3 – Illustration of thermal resistance test (for information) . 10
Figure 4 – Layout of the specimen surface for the thermal resistance test . 11
Figure 5 –Test equipment for thermal resistance across the thickness . 12
Figure 6 – Example of attachment of the specimen . 15
Figure 7 – Example of measurement of the thermal resistance on the plane . 16
Figure 8 – Use of the silicone grease . 17
Figure 9 – Test equipment for thermal resistance across the thickness (running water
tank specification) . 17
Figure 10 – Test equipment for thermal resistance across the thickness (cold plate) . 17
Figure A.1 – Example of classification and their application by base materials, PCBs
and final products . 20
Figure A.2 – The relation between thermal conductive parameter (W/(mK)) and heat
transfer coefficient parameter (mapping by substrate) . 21

Table 1 – Load heat (W) corresponding to range of thermal resistance on the plane
(K/W) . 12
Table 2 – Load heat (W) corresponding to range of thermal resistance to the direction
of the thickness (K/W) . 13

Table A.1 – Application and classification . 19
Table A.2 – The relation between thermal conductive parameter (W/(mK)) and heat
transfer coefficient parameter (mapping by zone) . 21

– 4 – IEC TR 61189-3-914:2017 © IEC 2017
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
TEST METHODS FOR ELECTRICAL MATERIALS, PRINTED BOARDS
AND OTHER INTERCONNECTION STRUCTURES AND ASSEMBLIES –

Part 3-914: Test method for thermal conductivity of printed
circuit boards for high-brightness LEDs – Guidelines

FOREWORD
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The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a technical report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
IEC TR 61189-3-914, which is a technical report, has been prepared by IEC technical
committee 91: Electronics assembly technology.

The text of this technical report is based on the following documents:
Enquiry draft Report on voting
91/1378/DTR 91/1403/RVC
Full information on the voting for the approval of this technical report can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
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 "http://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.
A bilingual version of this publication may be issued at a later date.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
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– 6 – IEC TR 61189-3-914:2017 © IEC 2017
INTRODUCTION
Development of this technical report has been discussed at TC 91 Plenary meeting in
Dongguan, China, October 30, 2015 as per 91/1343A/RM dated on January 22, 2016.
This document was developed as a supplementary document to the IEC 61189-3-913.
Therefore, this document has been developed as technical report.
This document is
...