SIST EN IEC 61189-2-808:2024

Test methods for electrical materials, printed board and other interconnection structures and assemblies - Part 2-808: Thermal resistance of an assembly by thermal transient method

IEC 61189-2-808:2024 describes the thermal transient method to characterize the thermal resistance of an assembly consisting of a heat source (e.g. power device), an attachment material (e.g. solder) and a dielectric layer with electrode. This method is suitable to determine the thermal resistance of materials and assembly methods as well as to optimize the thermal flux to a heat sink.
NOTE: This method is not intended to measure and specify the value of the thermal resistance of a dielectric material. For that purpose, other standards exist. Examples are given in Annex A.

Prüfverfahren für Elektromaterialien, Leiterplatten und andere Verbindungsstrukturen und Baugruppen – Teil 2-808: Thermischer Widerstand der dielektrischen Schicht durch thermische transiente Methode

Méthodes d'essai pour les matériaux électriques, les cartes imprimées et autres structures et assemblages d'interconnexion - Partie 2-808 : Résistance thermique d'un assemblage par la méthode du transitoire thermique

L’IEC 61189-2-808:2024 décrit la méthode du transitoire thermique pour caractériser la résistance thermique d'un assemblage constitué d'une source de chaleur (par exemple, un dispositif de puissance), d'un matériau de fixation (par exemple, une brasure) et d'une couche diélectrique avec électrode. Cette méthode permet de déterminer la résistance thermique des matériaux et des méthodes d'assemblage ainsi que d'optimiser le flux thermique vers un dissipateur thermique.
NOTE: Cette méthode n’est toutefois pas destinée à mesurer et à spécifier la valeur de la résistance thermique d'un matériau diélectrique. Il existe d’autres normes à cet effet. Des exemples sont donnés à l'Annexe A.

Preskusne metode za električne materiale, tiskana vezja in druge povezovalne strukture in sestave - 2-808. del: Meritev toplotne upornosti sestava z metodo toplotnega prehajanja

Standard IEC 61189-2-808:2024 opisuje metodo toplotnega prehajanja za karakterizacijo toplotne upornosti sestava, ki vključuje vir toplote (npr. električna naprava), material za pritrjevanje (npr. spajka) in dielektrično plast z elektrodo. Ta metoda je primerna za določevanje toplotne upornosti materialov in načinov pritrjevanja ter optimiziranje toplotnega toka do toplotnega ponora.
OPOMBA: Metoda ni namenjena za merjenje in določanje vrednosti toplotne upornosti dielektričnega materiala. Za ta namen obstajajo drugi standardi. Primeri so podani v dodatku A.

General Information

• Status: Published
• Public Enquiry End Date: 30-Apr-2023
• Publication Date: 02-Jul-2024
• ICS: 31.180 - Printed circuits and boards
• Technical Committee: ITIV - Electronics assembly technology and Environmental standardization
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 18-Jun-2024
• Due Date: 23-Aug-2024
• Completion Date: 03-Jul-2024
• Ref Project: EN IEC 61189-2-808:2024 - Test methods for electrical materials, printed board and other interconnection structures and assemblies - Part 2-808: Thermal resistance of an assembly by thermal transient method

Overview

EN IEC 61189-2-808:2024 (IEC 61189-2-808:2024) specifies a thermal transient method to characterize the thermal resistance of an assembly made up of a heat source (for example a power device), an attachment material (e.g. solder or die-attach), and a dielectric layer with electrode. The standard is part of the IEC 61189 series of test methods for electrical materials, printed boards and interconnection structures and assemblies. It is intended to support material characterization, process evaluation and thermal-path optimization to a heat sink - not to specify standalone dielectric thermal resistance (see Annex A for alternative methods).

Key topics and requirements

• Test scope and objective: Measure assembly-level thermal resistance using a thermal transient technique to evaluate heat-flow paths from device junction to a reference.
• Test specimen: Assembly comprising a heat source, attachment material, and dielectric layer with electrode; specific specimen geometries are defined in the document.
• Test equipment & procedure: Defined thermal transient test setup, recommended parameters and step-by-step procedures for acquiring transient thermal response data.
• Data analysis and results: How to derive and report thermal resistance values from transient measurements; example graphs and tabulated test results are provided.
• Uncertainty & repeatability: Informative Annex C addressing measurement uncertainty and repeatability considerations for thermal resistance tests.
• Special topics covered in annexes:
  • Annex A: Examples of other test methods for dielectric thermal resistance (e.g., ASTM methods referenced).
  • Annex B: Guidance on die-attach materials and related specimen designs.
  • Annex D: Thermostat equipment and calibration considerations for thermal transient testing.
• Reporting: Required content for test reports to ensure reproducibility and comparability.

Applications and who should use it

This standard is practical for professionals involved in thermal management and electronics assembly, including:

• PCB designers and thermal engineers optimizing thermal flux to heat sinks
• Electronics assembly engineers evaluating soldering and die-attach processes
• Component and materials manufacturers comparing thermal resistance of attachment materials
• Test laboratories performing standardized thermal characterization of assemblies
• R&D teams validating thermal performance of power devices, LEDs and other heat-generating components

Use cases:

• Comparing assembly methods or attachment materials for improved heat dissipation
• Verifying thermal-path improvements when integrating thermal vias or conductive planes
• Supporting qualification of manufacturing processes with repeatable thermal-resistance data

Related standards

• IEC 60194-2 (vocabulary for printed board and assembly technologies)
• Annex A lists alternative test methods for dielectric thermal resistance and references to ASTM methods (for example ASTM C1113, ASTM E1461, ASTM D5470 as informative references).

Keywords: thermal resistance, thermal transient method, IEC 61189-2-808, printed board, solder, die attach, thermal flux, heat sink, electronics assembly testing.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2024
Preskusne metode za električne materiale, tiskana vezja in druge povezovalne
strukture in sestave - 2-808. del: Meritev toplotne upornosti sestava z metodo
toplotnega prehajanja
Test methods for electrical materials, printed board and other interconnection structures
and assemblies - Part 2-808: Thermal resistance of an assembly by thermal transient
method
Prüfverfahren für Elektromaterialien, Leiterplatten und andere Verbindungsstrukturen
und Baugruppen – Teil 2-808: Thermischer Widerstand der dielektrischen Schicht durch
thermische transiente Methode
Méthodes d'essai pour les matériaux électriques, les cartes imprimées et autres
structures et assemblages d'interconnexion - Partie 2-808 : Résistance thermique d'un
assemblage par la méthode du transitoire thermique
Ta slovenski standard je istoveten z: EN IEC 61189-2-808:2024
ICS:
31.180 Tiskana vezja (TIV) in tiskane Printed circuits and boards
plošče
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 61189-2-808

NORME EUROPÉENNE
EUROPÄISCHE NORM May 2024
ICS 31.180
English Version
Test methods for electrical materials, printed board and other
interconnection structures and assemblies - Part 2-808: Thermal
resistance of an assembly by thermal transient method
(IEC 61189-2-808:2024)
Méthodes d'essai pour les matériaux électriques, les cartes Prüfverfahren für Elektromaterialien, Leiterplatten und
imprimées et autres structures et assemblages andere Verbindungsstrukturen und Baugruppen - Teil 2-
d'interconnexion - Partie 2-808 : Résistance thermique d'un 808: Thermischer Widerstand der dielektrischen Schicht
assemblage par la méthode du transitoire thermique durch thermische transiente Methode
(IEC 61189-2-808:2024) (IEC 61189-2-808:2024)
This European Standard was approved by CENELEC on 2024-05-30. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61189-2-808:2024 E

European foreword
The text of document 91/1935/FDIS, future edition 1 of IEC 61189-2-808, prepared by IEC/TC 91
"Electronics assembly technology" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 61189-2-808:2024.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2025-02-28
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2027-05-30
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 61189-2-808:2024 was approved by CENELEC as a
European Standard without any modification.
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod), the
relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60194-2 - Printed boards design, manufacture and - -
assembly - Vocabulary - Part 2: Common
usage in electronic technologies as well as
printed board and electronic assembly
technologies
IEC 61189-2-808 ®
Edition 1.0 2024-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Test methods for electrical materials, printed board and other interconnection

structures and assemblies –
Part 2-808: Thermal resistance of an assembly by thermal transient method

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

structures et assemblages d'interconnexion –

Partie 2-808 : Résistance thermique d'un assemblage par la méthode du

transitoire thermique
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.180  ISBN 978-2-8322-8804-7

– 2 – IEC 61189-2-808:2024 © IEC 2024
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Objective . 5
5 Test specimen . 6
6 Test equipment and procedures . 7
6.1 Test method and recommended test parameters . 7
6.2 Test equipment . 7
6.3 Test procedure . 8
7 Test result . 8
8 Report . 9
Annex A (informative) Additional test methods for thermal resistance . 11
Annex B (informative) Thermal resistance of die attach materials . 13
B.1 Test specimen . 13
B.2 Die attach materials . 13
B.3 Test result. 14
Annex C (informative) Uncertainty and repeatability for thermal resistance test . 16
C.1 Test specimen . 16
C.2 Test result. 16
Annex D (informative) Thermostat equipment . 18
Bibliography . 20

Figure 1 – Structure of an assembly . 6
Figure 2 – The fabricated test sample . 6
Figure 3 – Test structure for measuring thermal resistance . 8
Figure 4 – Test result for thermal resistance of an assembly . 9
Figure B.1 –Structure of test sample using die attach material . 13
Figure B.2 –The fabricated test sample using die attach material . 13
Figure B.3 – Test graph for die attach materials . 15
Figure C.1 – Test structure for measuring thermal resistance . 16
Figure C.2 – Test result for thermal resistance of assembly . 16
Figure D.1 – Connection of the thermostat unit to the T3Ster® main system unit . 18
Figure D.2 –Calibration diagram recorded by the T3Ster® thermostat . 19

Table 1 – Test result for thermal resistance of an assembly . 9
Table A.1 – ASTM C1113 . 11
Table A.2 – ASTM E1461 . 11
Table A.3 – ASTM D5470 . 12
Table B.1 – Properties for die attach materials . 14
Table B.2 – Test result for die attach materials . 15
Table C.1 – Test result for thermal resistance of assembly . 17

IEC 61189-2-808:2024 © IEC 2024 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
TEST METHODS FOR ELECTRICAL MATERIALS, PRINTED BOARD AND
OTHER INTERCONNECTION STRUCTURES AND ASSEMBLIES –

Part 2-808: Thermal resistance of an assembly
by thermal transient method
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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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
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the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 61189-2-808 has been prepared by IEC technical committee 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
91/1935/FDIS 91/1955/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
– 4 – IEC 61189-2-808:2024 © IEC 2024
The language used for the development of this International Standard 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 61189 series, published under the general title Test methods for
electrical materials, printed board 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, or
• revised.
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.

IEC 61189-2-808:2024 © IEC 2024 – 5 –
TEST METHODS FOR ELECTRICAL MATERIALS, PRINTED BOARD AND
OTHER INTERCONNECTION STRUCTURES AND ASSEMBLIES –

Part 2-808: Thermal resistance of an assembly
by thermal transient method
1 Scope
This part of IEC 61189 describes the thermal transient method to characterize the thermal
resistance of an assembly consisting of a heat source (e.g. power device), an attachment
material (e.g. solder) and a dielectric layer with electrode. This method is suitable to determine
the thermal resistance of materials and assembly methods as well as to optimize the thermal
flux to a heat sink.
NOTE This method is not intended to measure and specify the value of the thermal resistance of a dielectric
material. For that purpose, other standards exist. Examples are given in Annex A.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60194-2, Printed boards design, manufact
...