SIST EN IEC 60539-1:2023

Directly heated negative temperature coefficient thermistors - Part 1: Generic specification (IEC 60539-1:2022)

IEC 60539-1:2022 is applicable to directly heated negative temperature coefficient thermistors, typically made from transition metal oxide materials with semiconducting properties.
It establishes standard terms, inspection procedures and methods of test for use in sectional and detail specifications of electronic components for quality assessment or any other purpose.
This edition includes the following significant technical changes with respect to the previous edition:
Restructured completely to comply to ISO/IEC directives; categorization and reorganization of test methods into these categories; Annex X added for comparison to the previous edition; Some wordings, figures and references have been revised.

Direkt geheizte temperaturabhängige Widerstände mit negativem Temperaturkoeffizienten - Teil 1: Fachgrundspezifikation (IEC 60539-1:2022)

Thermistances à coefficient de température négatif à chauffage direct - Partie 1: Spécification générique (IEC 60539-1:2022)

L’IEC 60539-1:2022 s’applique aux thermistances à coefficient de température négatif à chauffage direct, généralement constituées d’oxydes de métaux de transition présentant des propriétés semi-conductrices.
Elle établit des termes, des procédures d’inspection et des méthodes d’essai normaux à utiliser dans les spécifications intermédiaires et particulières des composants électroniques, pour l’assurance de la qualité ou pour tout autre usage.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l’édition précédente:

   
1. cette édition a été entièrement remaniée conformément aux Directives ISO/IEC; différentes catégories ont été définies et les méthodes d’essai ont été réorganisées en fonction de ces catégories;

   
2. l’Annexe X a été ajoutée à titre de comparaison par rapport à l’édition précédente;

   
3. certaines formulations, figures et références ont été révisées.

Neposredno ogrevani termistorji z negativnim temperaturnim koeficientom - 1. del: Splošna specifikacija (IEC 60539-1:2022)

Standard IEC 60539-1:2022 se uporablja za neposredno ogrevane termistorje z negativnim temperaturnim koeficientom, ki so običajno izdelani iz materialov prehodnega kovinskega oksida s polprevodniškimi lastnostmi.
Določa splošne pogoje, inšpekcijske postopke in preskusne metode za uporabo v sekcijskih in podrobnih specifikacijah elektronskih komponent za oceno kakovosti ali kateri koli drug namen.
Ta izdaja v primerjavi s prejšnjo vključuje naslednje pomembne tehnične spremembe:
Popolnoma preoblikovana zaradi skladnosti z direktivami ISO/IEC; kategorizacija in reorganizacija preskusnih metod v te kategorije; dodan je dodatek X za primerjavo s prejšnjo izdajo; spremenjeno je bilo določeno besedilo, številke in sklicevanja.

General Information

• Status: Published
• Public Enquiry End Date: 17-Feb-2022
• Publication Date: 01-Mar-2023
• ICS: 31.040.30 - Thermistors
• Technical Committee: I11 - Imaginarni 11
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 13-Feb-2023
• Due Date: 20-Apr-2023
• Completion Date: 02-Mar-2023
• Ref Project: EN IEC 60539-1:2023 - Directly heated negative temperature coefficient thermistors - Part 1: Generic specification

Relations

• Revised: SIST EN 60539-1:2016 - Directly heated negative temperature coefficient thermistors - Part 1: Generic specification (IEC 60539-1:2016)
• Effective Date: 27-Apr-2021
• Revised: SIST EN 60539-1:2016/AC:2017 - Directly heated negative temperature coefficient thermistors - Part 1: Generic specification (IEC 60539-1:2016/COR1:2017)
• Effective Date: 27-Apr-2021

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN IEC 60539-1:2023
01-april-2023
Neposredno ogrevani termistorji z negativnim temperaturnim koeficientom - 1. del:
Splošna specifikacija (IEC 60539-1:2022)
Directly heated negative temperature coefficient thermistors - Part 1: Generic
specification (IEC 60539-1:2022)
Direkt geheizte temperaturabhängige Widerstände mit negativem
Temperaturkoeffizienten - Teil 1: Fachgrundspezifikation (IEC 60539-1:2022)
Thermistances à coefficient de température négatif à chauffage direct - Partie 1:
Spécification générique (IEC 60539-1:2022)
Ta slovenski standard je istoveten z: EN IEC 60539-1:2023
ICS:
31.040.30 Termistorji Thermistors
SIST EN IEC 60539-1:2023 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 60539-1:2023

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SIST EN IEC 60539-1:2023


EUROPEAN STANDARD EN IEC 60539-1

NORME EUROPÉENNE

EUROPÄISCHE NORM February 2023
ICS 31.040.30 Supersedes EN 60539-1:2016;
EN 60539-1:2016/AC:2017-09
English Version
Directly heated negative temperature coefficient thermistors -
Part 1: Generic specification
(IEC 60539-1:2022)
Thermistances à coefficient de température négatif à Direkt geheizte temperaturabhängige Widerstände mit
chauffage direct - Partie 1: Spécification générique negativem Temperaturkoeffizienten - Teil 1:
(IEC 60539-1:2022) Fachgrundspezifikation
(IEC 60539-1:2022)
This European Standard was approved by CENELEC on 2023-01-19. 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
© 2023 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN IEC 60539-1:2023 E

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SIST EN IEC 60539-1:2023
EN IEC 60539-1:2023 (E)
European foreword
The text of document 40/2975/FDIS, future edition 4 of IEC 60539-1, prepared by IEC/TC 40
"Capacitors and resistors for electronic equipment" was submitted to the IEC-CENELEC parallel vote
and approved by CENELEC as EN IEC 60539-1:2023.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2023-10-19
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2026-01-19
document have to be withdrawn

This document supersedes EN 60539-1:2016 and all of its amendments and corrigenda (if any).
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 60539-1:2022 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 60027-1 NOTE Approved as EN 60027-1
ISO 80000-1 NOTE Approved as EN ISO 80000-1
2

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SIST EN IEC 60539-1:2023
EN IEC 60539-1:2023 (E)
Annex A
(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.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60062 - Marking codes for resistors and capacitors EN 60062 -
IEC 60068-1 2013 Environmental testing - Part 1: General EN 60068-1 2014
and guidance
IEC 60068-2-1 - Environmental testing - Part 2-1: Tests - EN 60068-2-1 -
Test A: Cold
IEC 60068-2-2 - Environmental testing - Part 2-2: Tests - EN 60068-2-2 -
Test B: Dry heat
IEC 60068-2-6 - Environmental testing - Part 2-6: Tests - EN 60068-2-6 -
Test Fc: Vibration (sinusoidal)
IEC 60068-2-11 - Environmental testing - Part 2-11: Tests - EN IEC 60068-2-11 -
Test Ka: Salt mist
IEC 60068-2-14 - Environmental testing - Part 2-14: Tests - EN 60068-2-14 -
Test N: Change of temperature
IEC 60068-2-17 - Basic environmental testing procedures - EN 60068-2-17 -
Part 2-17: Tests - Test Q: Sealing
IEC 60068-2-20 - Environmental testing - Part 2-20: Tests - EN IEC 60068-2-20 -
Test Ta and Tb: Test methods for
solderability and resistance to soldering
heat of devices with leads
IEC 60068-2-21 2021 Environmental testing - Part 2-21: Tests - EN IEC 60068-2-21 2021
Test U: Robustness of terminations and
integral mounting devices
IEC 60068-2-27 2008 Environmental testing - Part 2-27: Tests - EN 60068-2-27 2009
Test Ea and guidance: Shock
IEC 60068-2-31 - Environmental testing - Part 2-31: Tests - EN 60068-2-31 -
Test Ec: Rough handling shocks, primarily
for equipment-type specimens
IEC 60068-2-38 - Environmental testing - Part 2-38: Tests - EN IEC 60068-2-38 -
Test Z/AD: Composite
temperature/humidity cyclic test
3

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SIST EN IEC 60539-1:2023
EN IEC 60539-1:2023 (E)
IEC 60068-2-45 1980 Basic environmental testing procedures - EN 60068-2-45 1992
Part 2-45: Tests - Test XA and guidance:
Immersion in cleaning solvents
+ A1 1993  + A1 1993
IEC 60068-2-52 - Environmental testing - Part 2-52: Tests - EN IEC 60068-2-52 -
Test Kb: Salt mist, cyclic (sodium chloride
solution)
IEC 60068-2-58 - Environmental testing - Part 2-58: Tests - EN 60068-2-58 -
Test Td: Test methods for solderability,
resistance to dissolution of metallization
and to soldering heat of surface mounting
devices (SMD)
IEC 60068-2-69 - Environmental testing - Part 2-69: Tests - EN 60068-2-69 -
Test Te/Tc: Solderability testing of
electronic components and printed boards
by the wetting balance (force
measurement) method
IEC 60068-2-78 - Environmental testing - Part 2-78: Tests - EN 60068-2-78 -
Test Cab: Damp heat, steady state
IEC 60294 - Measurement of the dimensions of a EN 60294 -
cylindrical component with axial
terminations
IEC 60717 - Method for the determination of the space EN 60717 -
required by capacitors and resistors with
unidirectional terminations
IEC 61193-2 - Quality assessment systems - Part 2: EN 61193-2 -
Selection and use of sampling plans for
inspection of electronic components and
packages
IEC 61249-2-7 - Materials for printed boards and other EN 61249-2-7 -
interconnecting structures - Part 2-7:
Reinforced base materials clad and unclad
- Epoxide woven E-glass laminated sheet
of defined flammability (vertical burning
test), copper-clad

4

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SIST EN IEC 60539-1:2023



IEC 60539-1

®


Edition 4.0 2022-12




INTERNATIONAL



STANDARD




NORME


INTERNATIONALE











Directly heated negative temperature coefficient thermistors –

Part 1: Generic specification



Thermistances à coefficient de température négatif à chauffage direct –

Partie 1: Spécification générique
















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 31.040.30 ISBN 978-2-8322-6192-7




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

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

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

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SIST EN IEC 60539-1:2023
– 2 – IEC 60539-1:2022 © IEC 2022
CONTENTS
FOREWORD . 8
1 Scope . 10
2 Normative references . 10
3 Terms and definitions . 11
4 General items . 21
4.1 Units and symbols. 21
4.2 Preferred values and appropriate category . 21
4.2.1 General . 21
4.2.2 Appropriate category . 21
4.3 Marking . 21
4.3.1 General . 21
4.3.2 Marking for small size types such as surface mount NTC thermistors . 22
4.3.3 Coding . 22
4.4 Quality assessment procedures . 22
5 General provisions for measurements and test methods . 22
5.1 General . 22
5.2 Standard atmospheric conditions for testing . 22
5.3 Drying and recovery . 23
5.3.1 Drying . 23
5.3.2 Recovery . 23
5.4 Mounting (for surface mount thermistors only) . 23
5.4.1 General . 23
5.4.2 Printed wiring board and land pattern . 23
5.4.3 Mounting on board . 23
6 Electrical tests and measurements . 25
6.1 Zero-power resistance . 25
6.1.1 General . 25
6.1.2 Measurement procedures . 25
6.1.3 Requirements . 25
6.2 B-value or resistance ratio . 25
6.2.1 General . 25
6.2.2 Requirements . 25
6.3 Insulation resistance (for insulated types only) . 26
6.3.1 General . 26
6.3.2 Test methods . 26
6.3.3 Applied voltage . 29
6.3.4 Requirements . 29
6.4 Voltage proof (for insulated types only) . 29
6.4.1 General . 29
6.4.2 Test voltage . 29
6.4.3 Requirements . 29
6.5 Resistance/temperature characteristic . 29
6.5.1 General . 29
6.5.2 Test methods . 29
6.5.3 Requirements . 29
6.6 Dissipation factor (δ) . 30

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SIST EN IEC 60539-1:2023
IEC 60539-1:2022 © IEC 2022 – 3 –
6.6.1 General . 30
6.6.2 Initial measurements . 30
6.6.3 Test methods . 30
6.6.4 Requirements . 31
6.7 Thermal time constant by ambient temperature change (τ ) . 31
a
6.7.1 The hot to cold thermal time constant for ambient temperature change . 31
6.7.2 The cold to hot thermal time constant for ambient temperature change . 32
6.7.3 Final measurements and requirements . 32
6.7.4 Requirements . 33
6.8 Thermal time constant by cooling after self-heating (τ ) . 33
c
6.8.1 General . 33
6.8.2 Initial measurements . 33
6.8.3 Preconditioning . 33
6.8.4 Test method . 34
6.8.5 Final measurements and requirements . 34
7 Mechanical test and measurements . 34
7.1 Visual examination and check of dimensions . 34
7.1.1 Visual examination . 34
7.1.2 Dimensions . 35
7.2 Robustness of terminations (not applicable to surface mount thermistors) . 35
7.2.1 General . 35
7.2.2 Initial measurements . 35
7.2.3 Test methods . 35
7.2.4 Test Ua – Tensile . 35
1
7.2.5 Test Ub – Bending (half the number of terminations) . 36
7.2.6 Test Uc – Torsion (remaining terminations). 36
7.2.7 Final measurements and requirements . 36
7.3 Vibration . 36
7.3.1 General . 36
7.3.2 Initial measurements . 36
7.3.3 Test procedures . 36
7.3.4 Final inspection, measurements and requirements. 37
7.4 Shock . 37
7.4.1 General . 37
7.4.2 Initial measurements . 37
7.4.3 Mounting . 37
7.4.4 Test procedures . 37
7.4.5 Final inspection, measurements and requirements. 37
7.5 Free fall . 37
7.5.1 General . 37
7.5.2 Initial measurements . 37
7.5.3 Test procedures . 38
7.5.4 Final inspection, measurements and requirements. 38
7.6 Shear (adhesion) test (for surface mount NTC thermistors only) . 38
7.6.1 General . 38
7.6.2 Initial measurements . 38
7.6.3 Test conditions . 38
7.6.4 Final inspection, measurements and requirements. 38

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SIST EN IEC 60539-1:2023
– 4 – IEC 60539-1:2022 © IEC 2022
7.7 Substrate bending test (for surface mount NTC thermistors only) . 38
7.7.1 General . 38
7.7.2 Initial measurements . 38
7.7.3 Test procedures . 38
7.7.4 Final inspection, measurements and requirements. 39
8 Environmental and climatic tests . 39
8.1 Rapid change of temperature . 39
8.1.1 General . 39
8.1.2 Initial measurements . 39
8.1.3 Test procedures . 39
8.1.4 Final inspection, measurements and requirements. 39
8.2 Thermal shock . 40
8.2.1 General . 40
8.2.2 Initial measurements . 40
8.2.3 Test procedures . 40
8.2.4 Final inspection, measurements and requirements. 40
8.3 Cold . 40
8.3.1 General . 40
8.3.2 Initial measurements . 40
8.3.3 Test procedures . 40
8.3.4 Final inspection, measurements and requirements. 41
8.4 Dry heat . 41
8.4.1 General . 41
8.4.2 Initial measurements . 41
8.4.3 Test procedures . 41
8.4.4 Final inspection, measurements and requirements. 41
8.5 Damp heat, steady state . 42
8.5.1 General . 42
8.5.2 Initial measurements . 42
8.5.3 Test procedures . 42
8.5.4 Recovery . 42
8.5.5 Final inspection, measurements and requirements. 42
8.6 Endurance . 42
8.6.1 General . 42
8.6.2 Endurance at room temperature with applied continuous maximum
current (I ) (for inrush current-limiting thermistors only) . 43
max25
8.6.3 Endurance at room temperature with applied cyclic maximum current
(I ) (for inrush current-limiting thermistors only) . 44
max25
8.6.4 Endurance at T and P (for other than inrush current-limiting
3 max

thermistors only) . 45
8.6.5 Endurance at upper category temperature . 46
8.6.6 Maximum permissible capacitance (for inrush current-limiting
thermistors only) . 47
8.7 Salt mist . 49
8.7.1 General . 49
8.7.2 Initial measurements . 49
8.7.3 Test conditions . 49
8.7.4 Final inspection, measurements and requirements. 49
8.8 Sealing . 49

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SIST EN IEC 60539-1:2023
IEC 60539-1:2022 © IEC 2022 – 5 –
8.9 Composite temperature/humidity cycle . 49
8.9.1 General . 49
8.9.2 Initial measurements . 49
8.9.3 Test conditions . 50
8.9.4 Final inspection, measurements and requirements. 50
9 Tests related to component assembly . 50
9.1 Resistance to soldering heat . 50
9.1.1 General . 50
9.1.2 Preconditioning . 50
9.1.3 Initial measurements . 50
9.1.4 Test procedure . 50
9.1.5 Recovery . 50
9.1.6 Final inspection, measurement and requirements . 51
9.2 Solderability . 51
9.2.1 General . 51
9.2.2 Initial measurements . 51
9.2.3 Test procedure . 51
9.2.4 Final inspection, measurements and requirements. 51
9.3 Component solvent resistance . 52
9.3.1 General . 52
9.3.2 Initial measurements . 52
9.3.3 Test conditions . 52
9.3.4 Requirements . 52
9.4 Solvent resistance of marking . 52
9.4.1 General . 52
9.4.2 Initial measurements . 52
9.4.3 Test conditions . 52
9.4.4 Requirements . 52
Annex A (normative) Rules for the preparation of detail specifications for directly
heated NTC thermistors for electronic equipme
...

SLOVENSKI STANDARD
oSIST prEN IEC 60539-1:2022
01-februar-2022
Neposredno ogrevani termistorji z negativnim temperaturnim koeficientom - 1. del:
Splošna specifikacija
Directly heated negative temperature coefficient thermistors - Part 1: Generic
specification
Direkt geheizte temperaturabhängige Widerstände mit negativem
Temperaturkoeffizienten - Teil 1: Fachgrundspezifikation
Thermistances à coefficient de température négatif à chauffage direct - Partie 1:
Spécification générique
Ta slovenski standard je istoveten z: prEN IEC 60539-1:2021
ICS:
31.040.30 Termistorji Thermistors
oSIST prEN IEC 60539-1:2022 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN IEC 60539-1:2022

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oSIST prEN IEC 60539-1:2022

40/2892/CDV

COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60539-1 ED4
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2021-11-26 2022-02-18
SUPERSEDES DOCUMENTS:
40/2833/CD, 40/2874/CC

IEC TC 40 : CAPACITORS AND RESISTORS FOR ELECTRONIC EQUIPMENT
SECRETARIAT: SECRETARY:
Netherlands Mr Ronald Drenthen
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:


Other TC/SCs are requested to indicate their interest, if any,
in this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY

SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft for
Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.

This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of which
they are aware and to provide supporting documentation.

TITLE:
Directly heated negative temperature coefficient thermistors - Part 1: Generic specification

PROPOSED STABILITY DATE: 2030

NOTE FROM TC/SC OFFICERS:


Copyright © 2021 International Electrotechnical Commission, IEC. All rights reserved. It is permitted to download this
electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.
You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without
permission in writing from IEC.

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oSIST prEN IEC 60539-1:2022
60539-1/Ed4/CDV  IEC:2021 (E) – 2 – 40/2892/CDV
1 CONTENTS
2
3 FOREWORD . 8
4 1 Scope . 10
5 2 Normative references . 10
6 3 Terms and definitions . 11
7 4 General items . 21
8 4.1 Units and symbols . 21
9 4.2 Preferred values and appropriate category . 21
10 4.2.1 General . 21
11 4.2.2 Appropriate category . 21
12 4.3 Marking . 21
13 4.3.1 General . 21
14 4.3.2 Marking for small size types such as surface mount NTC thermistors . 22
15 4.3.3 Coding . 22
16 4.4 Quality assessment procedures . 22
17 5 General provisions for measurements and test methods . 22
18 5.1 General . 22
19 5.2 Standard atmospheric conditions for testing . 22
20 5.3 Drying and recovery . 23
21 5.3.1 Drying . 23
22 5.3.2 Recovery . 23
23 5.4 Mounting (for surface mount thermistors only) . 23
24 5.4.1 General . 23
25 5.4.2 Printed wiring board and land pattern . 23
26 5.4.3 Mounting on board . 23
27 6 Electrical tests and measurements . 25
28 6.1 Zero-power resistance . 25
29 6.1.1 General . 25
30 6.1.2 Measurement procedures . 25
31 6.1.3 Requirements . 25
32 6.2 B-value or resistance ratio . 25
33 6.2.1 General . 25
34 6.2.2 Requirements . 25
35 6.3 Insulation resistance (for insulated types only) . 26
36 6.3.1 General . 26
37 6.3.2 Test methods . 26
38 6.3.3 Applied voltage . 28
39 6.3.4 Requirements . 29
40 6.4 Voltage proof (for insulated types only) . 29
41 6.4.1 General . 29
42 6.4.2 Test voltage . 29
43 6.4.3 Requirements . 29
44 6.5 Resistance/temperature characteristic . 29
45 6.5.1 General . 29
46 6.5.2 Test methods . 29
47 6.5.3 Requirements . 29
48 6.6 Dissipation factor (δ) . 29

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oSIST prEN IEC 60539-1:2022
60539-1/Ed4/CDV  IEC:2021 (E) – 3 – 40/2892/CDV
49 6.6.1 General . 29
50 6.6.2 Initial measurements . 29
51 6.6.3 Test methods . 30
52 6.6.4 Requirements . 31
53 6.7 Thermal time constant by ambient temperature change (τ ) . 31
a
54 6.7.1 The hot to cold thermal time constant for ambient temperature change . 31
55 6.7.2 The cold to hot thermal time constant for ambient temperature change . 32
56 6.7.3 Final measurements and requirements . 32
57 6.7.4 Requirements . 32
58 6.8 Thermal time constant by cooling after self-heating (τ ) . 33
c
59 6.8.1 General . 33
60 6.8.2 Initial measurements . 33
61 6.8.3 Preconditioning . 33
62 6.8.4 Test method . 34
63 6.8.5 Final measurements and requirements . 34
64 7 Mechanical test and measurements . 34
65 7.1 Visual examination and check of dimensions . 34
66 7.1.1 Visual examination . 34
67 7.1.2 Dimensions . 34
68 7.2 Robustness of terminations (not applicable to surface mount thermistors) . 34
69 7.2.1 General . 34
70 7.2.2 Initial measurements . 34
71 7.2.3 Test methods . 35
72 7.2.4 Test Ua – Tensile . 35
1
73 7.2.5 Test Ub – Bending (half the number of terminations) . 35
74 7.2.6 Test Uc – Torsion (remaining terminations) . 35
75 7.2.7 Final measurements and requirements . 35
76 7.3 Vibration . 35
77 7.3.1 General . 35
78 7.3.2 Initial measurements . 36
79 7.3.3 Test procedures. 36
80 7.3.4 Final inspection, measurements and requirements . 36
81 7.4 Shock . 36
82 7.4.1 General . 36
83 7.4.2 Initial measurements . 36
84 7.4.3 Mounting . 36
85 7.4.4 Test procedures. 36
86 7.4.5 Final inspection, measurements and requirements . 36
87 7.5 Free fall . 37
88 7.5.1 General . 37
89 7.5.2 Initial measurements . 37
90 7.5.3 Test procedures. 37
91 7.5.4 Final inspection, measurements and requirements . 37
92 7.6 Shear (adhesion) test (for surface mount NTC thermistors only) . 37
93 7.6.1 General . 37
94 7.6.2 Initial measurements . 37
95 7.6.3 Test conditions . 37
96 7.6.4 Final inspection, measurements and requirements . 37
97 7.7 Substrate bending test (for surface mount NTC thermistors only) . 37

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98 7.7.1 General . 37
99 7.7.2 Initial measurements . 38
100 7.7.3 Test procedures. 38
101 7.7.4 Final inspection, measurements and requirements . 38
102 8 Environmental and climatic tests . 38
103 8.1 Rapid change of temperature . 38
104 8.1.1 General . 38
105 8.1.2 Initial measurements . 38
106 8.1.3 Test procedures. 38
107 8.1.4 Final inspection, measurements and requirements . 39
108 8.2 Thermal shock . 39
109 8.2.1 General . 39
110 8.2.2 Initial measurements . 39
111 8.2.3 Test procedures. 39
112 8.2.4 Final inspection, measurements and requirements . 39
113 8.3 Cold . 39
114 8.3.1 General . 39
115 8.3.2 Initial measurements . 39
116 8.3.3 Test procedures. 39
117 8.3.4 Final inspection, measurements and requirements . 40
118 8.4 Dry heat . 40
119 8.4.1 General . 40
120 8.4.2 Initial measurements . 40
121 8.4.3 Test procedures. 40
122 8.4.4 Final inspection, measurements and requirements . 41
123 8.5 Damp heat, steady state . 41
124 8.5.1 General . 41
125 8.5.2 Initial measurements . 41
126 8.5.3 Test procedures. 41
127 8.5.4 Recovery . 41
128 8.5.5 Final inspection, measurements and requirements . 41
129 8.6 Endurance . 42
130 8.6.1 General . 42
131 8.6.2 Endurance at room temperature with applied continuous maximum
132 current (I ) (for inrush current-limiting thermistors only) . 42
max25
133 8.6.3 Endurance at room temperature with applied cyclic maximum current
134 (I ) (for inrush current-limiting thermistors only) . 43
max25
135 8.6.4 Endurance at T and P (for other than inrush current-limiting
3 max
136 thermistors only) . 44
137 8.6.5 Endurance at upper category temperature . 45
138 8.6.6 Maximum permissible capacitance (for inrush current-limiting
139 thermistors only) . 46
140 8.7 Salt mist . 48
141 8.7.1 General . 48
142 8.7.2 Initial measurements . 48
143 8.7.3 Test conditions . 48
144 8.7.4 Final inspection, measurements and requirements . 48
145 8.8 Sealing . 48
146 8.9 Composite temperature/humidity cycle . 48
147 8.9.1 General . 48

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148 8.9.2 Initial measurements . 48
149 8.9.3 Test conditions . 48
150 8.9.4 Final inspection, measurements and requirements . 48
151 9 Tests related to component assembly . 49
152 9.1 Resistance to soldering heat . 49
153 9.1.1 General . 49
154 9.1.2 Preconditioning . 49
155 9.1.3 Initial measurements . 49
156 9.1.4 Test procedure . 49
157 9.1.5 Recovery . 49
158 9.1.6 Final inspection, measurement and requirements . 49
159 9.2 Solderability . 49
160 9.2.1 General . 49
161 9.2.2 Initial measurements . 50
162 9.2.3 Test procedure . 50
163 9.2.4 Final inspection, measurements and requirements . 50
164 9.3 Component solvent resistance . 50
165 9.3.1 General . 50
166 9.3.2 Initial measurements . 50
167 9.3.3 Test conditions . 50
168 9.3.4 Requirements . 51
169 9.4 Solvent resistance of marking . 51
170 9.4.1 General . 51
171 9.4.2 Initial measurements . 51
172 9.4.3 Test conditions . 51
173 9.4.4 Requirements . 51
174 Annex A (normative) Rules for the preparation of detail specifications for directly
175 heated NTC thermistors for electronic equipment for use within quality
176 assessment systems . 52
177 A.1 Drafting . 52
178 A.2 Reference standard . 52
179 A.3 Circulation . 52
180 Annex B (informative) Typical examples of mountings for measurements of directly
181 heated thermistors . 53
182 B.1 Mounting for surface mount NTC thermistors . 53
183 Annex Q (informative) Quality assessment procedures . 55
184 Q.1 General . 55
185 Q.1.1 Scope of this annex . 55
186 Q.1.2 Quality assessment definitions . 56
187 Q.1.3 Rework . 56
188 Q.1.4 Alternative test methods . 56
189 Q.1.5 Certified test records of released lots . 57
190 Q.1.6 Unchecked parameters . 57
191 Q.1.7 Delayed delivery . 57
192 Q.1.8 Repair . 57
193 Q.1.9 Registration of approvals . 57
194 Q.1.10 Manufacture outside the geographical limits . 58
195 Q.2 Qualification approval (QA) procedures . 58
196 Q.2.1 Eligibility for qualification approval . 58
197 Q.2.2 Application for qualification approval . 58

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198 Q.2.3 Subcontracting . 58
199 Q.2.4 Test procedure for the initial product qualification approval . 58
200 Q.2.5 Granting of qualification approval . 58
201 Q.2.6 Maintenance of qualification approval . 58
202 Q.2.7 Quality conformance inspection . 58
203 Q.3 Capability approval (CA) procedures . 59
204 Q.3.1 General . 59
205 Q.3.2 Eligibility for capability approval . 59
206 Q.3.3 Application for capability approval . 59
207 Q.3.4 Subcontracting . 59
208 Q.3.5 Description of the capability . 59
209 Q.3.6 Demonstration and verification of capability . 60
210 Q.3.7 Granting of capability approval . 60
211 Q.3.8 Maintenance of capability approval . 60
212 Q.3.9 Quality conformance inspection . 60
213 Q.4 Technology approval (TA) procedure . 60
214 Q.4.1 General . 60
215 Q.4.2 Eligibility for technology approval . 61
216 Q.4.3 Application of technology approval . 61
217 Q.4.4 Subcontracting . 61
218 Q.4.5 Description of technology . 61
219 Q.4.6 Demonstration and verification of the technology . 61
220 Q.4.7 Granting of technology approval . 61
221 Q.4.8 Maintenance of technology approval . 61
222 Q.4.9 Quality conformance inspection . 61
223 Q.5 Interpretation of sampling plans and procedures as described in . 61
224 Q.6 Rules for the preparation of detail specifications for NTC thermistors for
225 electronic equipment for use within quality assessment systems . 62
226 Q.6.1 Drafting . 62
227 Q.6.2
...