IEC 61051-1:2018

Varistors for use in electronic equipment - Part 1: Generic specification

IEC 61051-1:2018 is a generic specification and is applicable to varistors with symmetrical voltage-current characteristics for use in electronic equipment. It establishes standard terms, inspection procedures and methods of test for use in sectional and detail specifications for quality assessment or any other purpose. This edition includes the following significant technical changes with respect to the previous edition:
a) 10 new terms and definitions – leaded varistors, surface mount varistors(SMV), electrostatic discharge (ESD), ESD clamping voltage, equivalent rectangular pulse duration, maximum peak current derating characteristic, rated average dissipation power, rated energy, abnormal overvoltage withstanding duration and temperature derating curve – have been added (see 3.6, 3.7, 3.14, 3.15, 3.19, 3.20, 3.23, 3.24, 3.25 and 3.29);
b) General requirements for electrical tests and 7 new test items – clamping voltage, ESD clamping voltage, maximum peak current, rated average dissipation power, rated energy, electrostatic discharge (ESD), robustness of terminations of surface mount varistors – have been added (see 6.5, 6.11, 6.12, 6.13, 6.14, 6.15, 6.16 and 6.17.8);
c) In 6.6, 6.7, 6.8, 6.9.3, 6.23.2, 6.23.4 and 6.26, following test items have been revised:
- Varistor voltage, leakage current and capacitance: more detailed requirements and information have been added;
- Voltage proof – foil method: the space between the edge of the foil and each termination has been changed from 1 mm ~ 1,5 mm to 3 mm ~ 3.5 mm for testing varistors not having axial terminations and the minimum space between the foil and the termination has been changed from 1 mm to 3 mm for testing varistors having axial terminations;
- Climatic sequence – dry heat: the method has been changed from Ba to Bb;
- Climatic sequence – cold: the method has been changed from Aa to Ab;
- Endurance at upper category temperature: the method of “applying test voltages in cycles of 1,5 h on and 0,5 h off” has been changed to the method of applying test voltages continuously throughout the test lasting for 1 000 h;
d) The test items of pulse current, voltage under pulse condition and bump have been deleted from the section of test and measurement procedures;
e) Annex A and the contents referring to the test fixture specified in Annex A have been deleted;
f) All contents related to silicon carbide varistors have been deleted;
g) A new normative annex entitled “Test pulses used in this specification” (Annex B) has been added;
h) A new informative annex entitled "Recommended measurement/test methods for characteristics and parameters for application reference" (Annex C) has been added, in which guidelines of measuring/testing characteristics and parameters for application reference including voltage vs. current characteristic, maximum peak current derating characteristic, thermal resistance and abnormal overvoltage withstanding duration have been given.

Varistances utilisées dans les équipements électroniques - Partie 1: Spécification générique

L'IEC 61051-1:2018 est une spécification générique applicable aux varistances à caractéristiques tension-courant symétriques, utilisées dans les équipements électroniques. Elle établit les termes normalisés, les procédures de contrôle et les procédures d'essai utilisés dans les spécifications intermédiaires et particulières à des fins d'assurance de la qualité ou à toute autre fin. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) 10 nouveaux termes et définitions (varistances à fils, varistances montées en surface (VMS), décharge électrostatique (DES), tension d'écrêtage de DES, durée d'impulsion rectangulaire équivalente, caractéristique de réduction du courant maximal de crête, puissance de dissipation moyenne assignée, énergie assignée, durée de résistance à une surtension anormale et courbe de réduction de la température) ont été ajoutés (voir 3.6, 3.7, 3.14, 3.15, 3.19, 3.20, 3.23, 3.24, 3.25 et 3.29);
b) des exigences générales pour les essais électriques et 7 nouveaux essais (tension d'écrêtage, tension d'écrêtage de DES, courant maximal de crête, puissance de dissipation moyenne assignée, énergie assignée, décharge électrostatique (DES), robustesse des sorties des varistances montées en surface) ont été ajoutés (voir 6.5, 6.11, 6.12, 6.13, 6.14, 6.15, 6.16 et 6.17.8);
c) en 6.6, 6.7, 6.8, 6.9.3, 6.23.2, 6.23.4 et 6.26, les essais suivants ont été révisés:
- Tension de la varistance, courant de fuite et capacité: des exigences et des informations plus détaillées ont été ajoutées;
- Tenue en tension – méthode de la feuille métallique: l'espace entre le bord de la feuille et chaque sortie a été modifié de 1 mm ~ 1,5 mm à 3 mm ~ 3,5 mm pour soumettre à l'essai les varistances qui ne possèdent aucune sortie axiale et l'espace minimal entre le bord de la feuille et la sortie a été modifié de 1 mm à 3 mm pour soumettre à l'essai les varistances qui possèdent des sorties axiales;
- Séquence climatique – chaleur sèche: la méthode a été modifiée (Ba en Bb);
- Séquence climatique – froid: la méthode a été modifiée (Aa en Ab);
- Endurance à la température maximale de catégorie: la méthode consistant à "appliquer des tensions d'essai par cycles de 1,5 h d'application et de 0,5 h de repos" a été modifiée au profit de la méthode consistant à appliquer des tensions d'essai en continu tout au long de l'essai qui dure 1 000 h;
d) les essais de courant d'impulsion, de tension en condition d'impulsion et de secousses ont été supprimés de l'article concernant les procédures d'essai et de mesure;
e) l'Annexe A et les contenus qui font référence aux appareils de montage d'essai spécifiés à l'Annexe A ont été supprimés;
f) tous les contenus concernant les varistances au carbure de silicium ont été supprimés;
g) une nouvelle annexe normative intitulée "Impulsions d'essai utilisées dans la présente spécification" (Annexe B) a été ajoutée;
h) une nouvelle annexe informative intitulée "Méthodes de mesure/d'essai recommandées pour les caractéristiques et paramètres pour référence d'application" (Annexe C) a été ajoutée; elle donne des lignes directrices pour les caractéristiques et paramètres de mesure/d'essai et pour référence d'application (notamment la caractéristique tension-courant, la caractéristique de réduction du courant maximal de crête, la résistance thermique et la durée de résistance à une surtension anormale).

General Information

• Status: Published
• Publication Date: 28-Oct-2018
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 31.020 - Electronic components in general
• ICS: 31.040.99 - Other resistors
• ICS: 31.240 - Mechanical structures for electronic equipment
• Technical Committee: TC 40 - Capacitors and resistors for electronic equipment
• Drafting Committee: MT 61051-1 - TC 40/MT 61051-1
• Current Stage: PPUB - Publication issued
• Start Date: 05-Oct-2018
• Completion Date: 29-Oct-2018

Relations

• Revises: IEC 61051-1:2007 - Varistors for use in electronic equipment - Part 1: Generic specification
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61051-1 ®
Edition 3.0 2018-10
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Varistors for use in electronic equipment –
Part 1: Generic specification
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
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About the IEC
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International Standards for all electrical, electronic and related technologies.

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IEC 61051-1 ®
Edition 3.0 2018-10
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Varistors for use in electronic equipment –

Part 1: Generic specification
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.040.99 ISBN 978-2-8322-6211-5

– 2 – IEC 61051-1:2018 RLV © IEC 2018
CONTENTS
FOREWORD . 7
1 Scope . 10
2 Normative references . 10
3 Terms and definitions . 12
4 Technical data . 19
4.1 Units, symbols and terminology . 19
4.2 Preferred values and characteristics . 19
4.3 Marking . 19
4.3.1 General . 19
4.3.2 Coding . 19
5 Quality assessment procedures . 20
5.1 General . 20
5.1.1 Overview . 20
5.1.2 Applicability of qualification approval . 20
5.1.3 Applicability of capability approval . 20
5.1.4 Applicability of technology approval . 21
5.2 Primary stage of manufacture . 21
5.3 Subcontracting . 21
5.4 Structurally similar components . 21
5.5 Qualification approval procedures . 22
5.5.1 Eligibility for qualification approval . 22
5.5.2 Application for qualification approval . 22
5.5.3 Test procedure for qualification approval . 22
5.5.4 Granting of qualification approval . 22
5.5.5 Maintenance of qualification approval . 22
5.5.6 Quality conformance inspection . 22
5.6 Capability approval procedures . 23
5.6.1 General . 23
5.6.2 Eligibility for capability approval . 23
5.6.3 Application for capability approval . 23
5.6.4 Description of capability . 24
5.6.5 Demonstration and verification of capability . 24
5.6.6 Programme for capability approval . 25
5.6.7 Capability approval test report . 25
5.6.8 Abstract of description of capability . 25
5.6.9 Modifications likely to affect the capability approval . 25
5.6.10 Initial capability approval . 26
5.6.11 Granting of capability approval . 27
5.6.12 Maintenance of capability approval . 27
5.6.13 Extension of capability approval . 27
5.6.14 Quality conformance inspection . 27
5.7 Rework and repair. 28
5.7.1 Rework . 28
5.7.2 Repair . 28
5.8 Release for delivery . 28
5.8.1 General . 28

5.8.2 Certified records of released lots . 28
5.8.3 Delayed delivery . 28
5.8.4 Release for delivery before the completion of Group B tests . 29
5.9 Alternative test methods . 29
5.10 Unchecked parameters . 29
5.11 Characteristics and parameters for application reference . 29
5.12 Technology approval procedures . 29
5.12.1 General . 29
5.12.2 Eligibility for technology approval . 29
5.12.3 Application of technology approval . 30
5.12.4 Description of technology . 30
5.12.5 Demonstration and verification of the technology . 30
5.12.6 Granting of technology approval . 30
5.12.7 Maintenance of technology approval . 30
5.12.8 Quality conformance inspection . 30
5.12.9 Failure rate level determination. 30
5.12.10 Outgoing quality level . 30
6 Test and measurement procedures . 30
6.1 General . 30
6.2 Standard atmospheric conditions . 31
6.2.1 Standard atmospheric conditions for testing . 31
6.2.2 Recovery conditions . 31
6.2.3 Referee conditions . 31
6.2.4 Reference conditions . 31
6.3 Drying and recovery . 32
6.3.1 General . 32
6.3.2 Procedure I . 32
6.3.3 Procedure II . 32
6.4 Visual examination and check of dimensions . 32
6.4.1 Visual examination . 32
6.4.2 Marking . 32
6.4.3 Dimensions (gauging) . 32
6.4.4 Dimensions (detail) . 32
Nominal varistor voltage or leakage current (not applicable to pulse
measurements) .
Test procedure .
Measurement and requirements .
Pulse current .
Standard pulse currents .
Tolerances .
Measurement of the pulse current .
4.7 Voltage under pulse condition .
4.8 Capacitance .
6.5 General requirements for electrical tests . 34
6.6 Varistor voltage . 35
6.7 Leakage current . 36
6.8 Capacitance . 36
6.9 Voltage proof (for insulated varistors only) . 36
6.9.1 General . 36
...

IEC 61051-1 ®
Edition 3.0 2018-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Varistors for use in electronic equipment –
Part 1: Generic specification
Varistances utilisées dans les équipements électroniques –
Partie 1: Spécification générique

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
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About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

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bibliographical information on IEC International Standards, electrical terms containing 21 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - webstore.iec.ch/advsearchform IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 67 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

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IEC 61051-1 ®
Edition 3.0 2018-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Varistors for use in electronic equipment –

Part 1: Generic specification
Varistances utilisées dans les équipements électroniques –

Partie 1: Spécification générique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.040.99 ISBN 978-2-8322-6089-0

– 2 – IEC 61051-1:2018 © IEC 2018
CONTENTS
FOREWORD . 7
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 10
4 Technical data . 15
4.1 Units, symbols and terminology . 15
4.2 Preferred values and characteristics . 15
4.3 Marking . 15
4.3.1 General . 15
4.3.2 Coding . 16
5 Quality assessment procedures . 16
5.1 General . 16
5.1.1 Overview . 16
5.1.2 Applicability of qualification approval . 16
5.1.3 Applicability of capability approval . 16
5.1.4 Applicability of technology approval . 17
5.2 Primary stage of manufacture . 17
5.3 Subcontracting . 17
5.4 Structurally similar components . 17
5.5 Qualification approval procedures . 18
5.5.1 Eligibility for qualification approval. 18
5.5.2 Application for qualification approval . 18
5.5.3 Test procedure for qualification approval . 18
5.5.4 Granting of qualification approval . 18
5.5.5 Maintenance of qualification approval . 18
5.5.6 Quality conformance inspection . 18
5.6 Capability approval procedures . 19
5.6.1 General . 19
5.6.2 Eligibility for capability approval . 19
5.6.3 Application for capability approval . 19
5.6.4 Description of capability . 19
5.6.5 Demonstration and verification of capability . 20
5.6.6 Programme for capability approval . 21
5.6.7 Capability approval test report . 21
5.6.8 Abstract of description of capability . 21
5.6.9 Modifications likely to affect the capability approval . 21
5.6.10 Initial capability approval . 21
5.6.11 Granting of capability approval . 22
5.6.12 Maintenance of capability approval . 23
5.6.13 Extension of capability approval . 23
5.6.14 Quality conformance inspection . 23
5.7 Rework and repair . 23
5.7.1 Rework . 23
5.7.2 Repair . 24
5.8 Release for delivery . 24
5.8.1 General . 24

5.8.2 Certified records of released lots . 24
5.8.3 Delayed delivery . 24
5.8.4 Release for delivery before the completion of Group B tests . 24
5.9 Alternative test methods . 24
5.10 Unchecked parameters . 25
5.11 Characteristics and parameters for application reference . 25
5.12 Technology approval procedures . 25
5.12.1 General . 25
5.12.2 Eligibility for technology approval . 25
5.12.3 Application of technology approval . 25
5.12.4 Description of technology . 25
5.12.5 Demonstration and verification of the technology . 25
5.12.6 Granting of technology approval . 26
5.12.7 Maintenance of technology approval . 26
5.12.8 Quality conformance inspection . 26
5.12.9 Failure rate level determination . 26
5.12.10 Outgoing quality level . 26
6 Test and measurement procedures . 26
6.1 General . 26
6.2 Standard atmospheric conditions . 26
6.2.1 Standard atmospheric conditions for testing. 26
6.2.2 Recovery conditions . 27
6.2.3 Referee conditions . 27
6.2.4 Reference conditions . 27
6.3 Drying and recovery .
...