Environmental testing - Part 2-21: Tests - Test U: Robustness of terminations and integral mounting devices

IEC 60068-2-21:2021 is applicable to all electrical and electronic components whose terminations or integral mounting devices are liable to be submitted to stresses during normal assembly or handling operations and is also applicable to surface mount devices (SMDs).
This seventh edition cancels and replaces the sixth edition, published in 2006, and IEC 60068‑2‑77:1999. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:  
integration of parts of IEC 60068-2-77 (see Annex X); IEC 60068-2-77 is withdrawn with the publication of this document;
Annex X is added to show the correlation of the clauses and subclauses in this edition of IEC 60068-2-21 with the clauses in IEC 60068-2-21:2006 and IEC 60068-2-77:1999.

Essais d'environnement - Partie 2-21: Essais - Essai U: Robustesse des sorties et des dispositifs de montage incorporés

L’IEC 60068-2-21:2021 s’applique à tous les composants électriques et électroniques dont les sorties ou les dispositifs de montage incorporés sont susceptibles d’être soumis à des contraintes au cours des opérations normales de montage ou de manipulation, et elle s’applique également aux composants pour montage en surface (CMS).
Cette septième édition annule et remplace la sixième édition, parue en 2006, et l’IEC 60068‑2‑77:1999. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:  
intégration des parties de l’IEC 60068-2-77 (voir l’Annexe X). L’IEC 60068-2-77 a été retirée après la publication du présent document;
l’Annexe X a été ajoutée pour montrer la corrélation des articles et des paragraphes de la présente édition de l’IEC 60068-2-21 avec ceux de l’IEC 60068-2-21:2006 et de l’IEC 60068-2-77:1999.

General Information

Status
Published
Publication Date
07-Jul-2021
Current Stage
PPUB - Publication issued
Completion Date
08-Jul-2021
Ref Project

Buy Standard

Standard
IEC 60068-2-21:2021 - Environmental testing - Part 2-21: Tests - Test U: Robustness of terminations and integral mounting devices
English and French language
86 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

IEC 60068-2-21
Edition 7.0 2021-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Environmental testing –
Part 2-21: Tests – Test U: Robustness of terminations and integral mounting
devices
Essais d’environnement –
Partie 2-21: Essais – Essai U: Robustesse des sorties et des dispositifs de
montage incorporés
IEC 60068-2-21:2021-07(en-fr)
---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
Copyright © 2021 IEC, Geneva, Switzerland

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

either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC

copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or

your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite

ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie

et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des

questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez

les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
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 corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC online collection - oc.iec.ch

The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the

variety of criteria (reference number, text, technical publications previews. With a subscription you will always

committee, …). It also gives information on projects, replaced have access to up to date content tailored to your needs.

and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 000 terminological entries in English
details all new publications released. Available online and
and French, with equivalent terms in 18 additional languages.
once a month by email.
Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC

La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des

Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC

Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la

plus récente, un corrigendum ou amendement peut avoir été publié.
Recherche de publications IEC - IEC online collection - oc.iec.ch

webstore.iec.ch/advsearchform Découvrez notre puissant moteur de recherche et consultez

La recherche avancée permet de trouver des publications IEC gratuitement tous les aperçus des publications. Avec un

en utilisant différents critères (numéro de référence, texte, abonnement, vous aurez toujours accès à un contenu à jour

comité d’études, …). Elle donne aussi des informations sur adapté à vos besoins.
les projets et les publications remplacées ou retirées.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
Le premier dictionnaire d'électrotechnologie en ligne au
Restez informé sur les nouvelles publications IEC. Just
monde, avec plus de 22 000 articles terminologiques en
Published détaille les nouvelles publications parues.
anglais et en français, ainsi que les termes équivalents dans
Disponible en ligne et une fois par mois par email.
16 langues additionnelles. Egalement appelé Vocabulaire
Electrotechnique International (IEV) en ligne.
Service Clients - webstore.iec.ch/csc
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
sales@iec.ch.
---------------------- Page: 2 ----------------------
IEC 60068-2-21
Edition 7.0 2021-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Environmental testing –
Part 2-21: Tests – Test U: Robustness of terminations and integral mounting
devices
Essais d’environnement –
Partie 2-21: Essais – Essai U: Robustesse des sorties et des dispositifs de
montage incorporés
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 19.040; 31.190 ISBN 978-2-8322-9999-9

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
---------------------- Page: 3 ----------------------
– 2 – IEC 60068-2-21:2021 © IEC 2021
CONTENTS

FOREWORD ........................................................................................................................... 5

1 Scope .............................................................................................................................. 7

2 Normative references ...................................................................................................... 7

3 Terms and definitions ...................................................................................................... 8

4 Tests Ua: Robustness of terminals against axial stresses ................................................ 8

4.1 Object ..................................................................................................................... 8

4.2 Application .............................................................................................................. 8

4.3 General description ................................................................................................. 8

4.4 Preconditioning ....................................................................................................... 8

4.5 Initial measurements ............................................................................................... 8

4.6 Test procedures ...................................................................................................... 9

4.6.1 Test Ua : Tensile ............................................................................................. 9

4.6.2 Test Ua : Thrust ............................................................................................ 10

4.7 Final measurements .............................................................................................. 11

4.8 Information to be given in the relevant specification .............................................. 11

5 Tests Ub: Robustness of terminals against bending stresses ......................................... 11

5.1 Object ................................................................................................................... 11

5.2 Application ............................................................................................................ 12

5.2.1 General ......................................................................................................... 12

5.2.2 Pliable terminations ....................................................................................... 12

5.2.3 Rigid and all other terminations ..................................................................... 12

5.3 General description ............................................................................................... 13

5.4 Preconditioning ..................................................................................................... 14

5.5 Initial measurements ............................................................................................. 14

5.6 Test procedures .................................................................................................... 14

5.6.1 Test Ub (for wire and strip terminations)....................................................... 14

5.6.2 Test Ub (for tag terminations) ....................................................................... 16

5.6.3 Test Ub Simultaneous bending ..................................................................... 17

5.7 Final measurements .............................................................................................. 17

5.8 Information to be given in the relevant specification .............................................. 17

6 Test Uc: Torsion ............................................................................................................ 18

6.1 Object ................................................................................................................... 18

6.2 Application ............................................................................................................ 18

6.3 General description ............................................................................................... 18

6.4 Preparation of the specimen ................................................................................. 18

6.5 Initial measurements ............................................................................................. 18

6.6 Test procedure ...................................................................................................... 19

6.7 Final measurements .............................................................................................. 20

6.8 Information to be given in the relevant specification .............................................. 20

7 Test Ud: Torque ............................................................................................................ 20

7.1 Object ................................................................................................................... 20

7.2 Application ............................................................................................................ 20

7.3 General description ............................................................................................... 21

7.4 Preconditioning ..................................................................................................... 21

7.5 Initial measurements ............................................................................................. 21

---------------------- Page: 4 ----------------------
IEC 60068-2-21:2021 © IEC 2021 – 3 –

7.6 Test procedure ...................................................................................................... 21

7.6.1 Terminations with threaded studs or screws .................................................. 21

7.6.2 Other test configurations................................................................................ 23

7.7 Final measurements .............................................................................................. 23

7.8 Information to be given in the relevant specification .............................................. 23

8 Test Ue: Robustness of terminations for SMD in the mounted state ............................... 24

8.1 Object ................................................................................................................... 24

8.2 Application ............................................................................................................ 24

8.3 Substrate for test method Ue ................................................................................ 24

8.4 Mounting ............................................................................................................... 26

8.4.1 Dimensions .................................................................................................... 26

8.4.2 Possible mounting methods ........................................................................... 26

8.4.3 Mounting method for substrate bending, pull-off, push-off and shear ............. 26

8.5 Preconditioning ..................................................................................................... 27

8.6 Initial measurements ............................................................................................. 27

8.7 Test methods ........................................................................................................ 27

8.7.1 Test Ue : Substrate bending test ................................................................... 27

8.7.2 Test Ue : Pull-off and push-off test ................................................................ 28

8.7.3 Test Ue : Shear test ...................................................................................... 30

8.8 Final measurements .............................................................................................. 32

8.8.1 Recovery ....................................................................................................... 32

8.8.2 Visual examination of terminations ................................................................ 32

8.8.3 Electrical characteristics ................................................................................ 32

8.8.4 Hidden defect ................................................................................................ 32

8.9 Information to be given in the relevant specification .............................................. 32

9 Test Uf: Robustness of component body ........................................................................ 34

9.1 Object ................................................................................................................... 34

9.2 Application ............................................................................................................ 34

9.3 General description ............................................................................................... 34

9.4 Preconditioning ..................................................................................................... 34

9.5 Initial measurement .............................................................................................. 34

9.6 Test procedure ...................................................................................................... 34

9.6.1 Test Uf : Body strength ................................................................................. 34

9.6.2 Test Uf : Impact shock .................................................................................. 36

9.7 Final measurements .............................................................................................. 38

9.7.1 Recovery ....................................................................................................... 38

9.7.2 Visual examination ........................................................................................ 39

9.7.3 Electrical characteristics ................................................................................ 39

9.7.4 Hidden defect ................................................................................................ 39

9.8 Information to be given in the relevant specification .............................................. 39

Annex X (informative) Cross-reference for references to the previous editions of this

document .............................................................................................................................. 40

X.1 Cross-reference for references to the previous edition of IEC 60068‑2‑21 ............. 40

X.2 Cross-reference for references to the last edition of IEC 60068‑2‑77 .................... 41

Bibliography .......................................................................................................................... 43

Figure 1 – Direction of the applied pull force F in test Ua ..................................................... 9

p 1
---------------------- Page: 5 ----------------------
– 4 – IEC 60068-2-21:2021 © IEC 2021

Figure 2 – Direction of the applied thrust F in test Ua ......................................................... 10

t 2

Figure 3 – Displacement of pliable lead wires in test Ub ....................................................... 12

Figure 4 – Bending force applied to a specimen with non-pliable terminations ...................... 13

Figure 5 – Sequential test procedure of test Ub, Method 1 .................................................... 15

Figure 6 – Sequential test procedure of test Ub, Methods 2 and 3......................................... 16

Figure 7 – Clamp for the testing of short terminations ........................................................... 17

Figure 8 – Preparatory bending of a lead wire for test Uc ...................................................... 18

Figure 9 – Torsion test method 1: Rotation of clamped specimen body ................................. 19

Figure 10 – Torsion test method 2: Rotation of clamped other lead wire................................ 20

Figure 11 – Assembly for the torque test applied to a threaded stud ..................................... 22

Figure 12 – Preparation of a threaded termination for the torque test .................................... 22

Figure 13 – Assembly for the torque test applied to an embedded nut ................................... 23

Figure 14 – Example of substrate for test method Ue ............................................................ 25

Figure 15 – Substrate bending test ....................................................................................... 28

Figure 16 – Test Ue , pull-off test ......................................................................................... 29

Figure 17 – Test Ue , push-off test ....................................................................................... 30

Figure 18 – Test Ue , shear test ........................................................................................... 31

Figure 19 – SMD Body strength test Uf applied to a rectangular specimen .......................... 35

Figure 20 – SMD Body strength test Uf applied to a MELF specimen .................................. 36

Figure 21 – Example of an apparatus for test Uf .................................................................. 37

Figure 22 – Example of a piston ............................................................................................ 37

Figure 23 – Examples of the application of the SMD Body impact shock test Uf .................. 38

Table 1 – Selection of test methods suitable for specific terminations/leads ............................ 7

Table 2 – Value of applied pull force for test Ua .................................................................. 10

Table 3 – Value of applied thrust for test Ua ........................................................................ 11

Table 4 – Value of applied force for test Ub .......................................................................... 13

Table 5 – Torque severity ..................................................................................................... 21

Table X.1 – Cross-reference to clauses ................................................................................ 40

Table X.2 – Cross-reference to figures .................................................................................. 41

Table X.3 – Cross reference to tables ................................................................................... 41

Table X.4 – Cross-reference to clauses ................................................................................ 42

Table X.5 – Cross-reference to figures .................................................................................. 42

---------------------- Page: 6 ----------------------
IEC 60068-2-21:2021 © IEC 2021 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ENVIRONMENTAL TESTING –
Part 2-21: Tests – Test U: Robustness of
terminations and integral mounting devices
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

co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and

in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,

Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their

preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with

may participate in this preparatory work. International, governmental and non-governmental organizations liaising

with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for

Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.

2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international

consensus of opinion on the relevant subjects since each technical committee has representation from all

interested IEC National Committees.

3) IEC Publications have the form of recommendations for international use and are accepted by IEC National

Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC

Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any

misinterpretation by any end user.

4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications

transparently to the maximum extent possible in their national and regional publications. Any divergence between

any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.

5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity

assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any

services carried out by independent certification bodies.

6) All users should ensure that they have the latest edition of this publication.

7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and

members of its technical committees and IEC National Committees for any personal injury, property damage or

other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and

expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.

8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent

rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 60068-2-21 has been prepared by IEC technical committee 91:

Electronics assembly technology.

This seventh edition cancels and replaces the sixth edition, published in 2006, and

IEC 60068-2-77:1999. This edition constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:

a) integration of parts of IEC 60068-2-77 (see Annex X); IEC 60068-2-77 is withdrawn with the

publication of this document;

b) Annex X is added to show the correlation of the clauses and subclauses in this edition of

IEC 60068-2-21 with the clauses in IEC 60068-2-21:2006 and IEC 60068-2-77:1999.
---------------------- Page: 7 ----------------------
– 6 – IEC 60068-2-21:2021 © IEC 2021
The text of this International Standard is based on the following documents:
FDIS Report on voting
91/1732/FDIS 91/1742/RVD

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.

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 complete list of all parts comprising the IEC 60068 series, under the general title

Environmental testing, 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.
---------------------- Page: 8 ----------------------
IEC 60068-2-21:2021 © IEC 2021 – 7 –
ENVIRONMENTAL TESTING –
Part 2-21: Tests – Test U: Robustness of
terminations and integral mounting devices
1 Scope

This part of IEC 60068 is applicable to all electrical and electronic components whose

terminations or integral mounting devices are liable to be submitted to stresses during normal

assembly or handling operations and is also applicable to surface mount devices (SMDs).

The recommended test methods suitable for specific terminations/lead of devices are shown in

Table 1.
Table 1 – Selection of test methods suitable for specific terminations/leads
Test method Component Mounted/not See Clause
mounted
Test Type
Ua Tensile Leaded devices Not mounted Clause 4
Ua Thrust Leaded devices Not mounted Clause 4
Ub Bending Leaded devices Not mounted Clause 5
Uc Torsion Leaded devices Not mounted Clause 6
Ud Torque Threaded stud, screw or Not mounted Clause 7
other terminations
Ue Substrate Surface mount devices Mounted Clause 8
bending
Ue Pull/push Surface mount devices Mounted Clause 8
Ue Shear Surface mount devices Mounted Clause 8
Uf Body Surface mount devices Not mounted Clause 9
strength
Impact
Uf Surface mount devices Not mounted Clause 9
shock
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 60068-1:2013, Environmental testing – Part 1: General and guidance

IEC 60068-2-58:2015, Environmental testing – Part 2-58: Tests – Test Td – Test methods for

solderability, resistance to dissolution of metallization and to soldering heat of surface mounting

devices (SMD)

IEC 60194-2, Printed board design, manufacture and assembly – Vocabulary – Part 2: Common

usage in electronic technologies as well as printed board and electronic assembly technologies

---------------------- Page: 9 ----------------------
– 8 – IEC 60068-2-21:2021 © IEC 2021

IEC 61191-2, Printed board assemblies – Part 2: Sectional specification – Requirements for

surface mount soldered assemblies
3 Terms and definitions

For the purposes of this document, the terms and definitions given in IEC 60194-2 and the

following apply.

ISO and IEC maintain terminological databases for use in standardization at the following

addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
integral mounting device

auxiliary means to make a mechanical connection of a terminal or other mounting element to

the inside of the component and its case

Note 1 to entry: Such means can be a stud, a nut, a bolt, or similar mechanical parts for fixing.

4 Tests Ua: Robustness of terminals against axial stresses
4.1 Object

The purpose of these tests is to verify that the terminations and their attachments to the body

of the component will withstand such axial stresses as are likely to be applied during normal

assembly or handling operations.
4.2 Application

The relevant specification shall state whether this test is applicable. It shall be carried out on

all the terminations, except where a component has more than three
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.