IEC 60068-2-21:1999

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

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.

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

Applicable 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.

General Information

• Status: Published
• Publication Date: 06-Jan-1999
• ICS: 19.040 - Environmental testing
• ICS: 31.190 - Electronic component assemblies
• Technical Committee: TC 91 - Electronics assembly technology
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 22-Jun-2006

Relations

• Revised: IEC 60068-2-21:2006 - Environmental testing - Part 2-21: Tests - Test U: Robustness of terminations and integral mounting devices
• Effective Date: 05-Sep-2023

Standards Content (Sample)

INTERNATIONAL
IEC
STANDARD
60068-2-21
Fifth edition
1999-01
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 fixation

Reference number
Numbering
As from 1 January 1997 all IEC publications are issued with a designation in the
60000 series.
Consolidated publications
Consolidated versions of some IEC publications including amendments are

available. For example, edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the
base publication, the base publication incorporating amendment 1 and the base

publication incorporating amendments 1 and 2.

Validity of this publication
The technical content of IEC publications is kept under constant review by the IEC,
thus ensuring that the content reflects current technology.
Information relating to the date of the reconfirmation of the publication is available
in the IEC catalogue.
Information on the subjects under consideration and work in progress undertaken by
the technical committee which has prepared this publication, as well as the list of
publications issued, is to be found at the following IEC sources:
• IEC web site*
• Catalogue of IEC publications
Published yearly with regular updates
(On-line catalogue)*
• IEC Bulletin
Available both at the IEC web site* and as a printed periodical
Terminology, graphical and letter symbols
For general terminology, readers are referred to IEC 60050: International
Electrotechnical Vocabulary (IEV).
For graphical symbols, and letter symbols and signs approved by the IEC for
general use, readers are referred to publications IEC 60027: Letter symbols to be
used in electrical technology, IEC 60417: Graphical symbols for use on equipment.
Index, survey and compilation of the single sheets and IEC 60617: Graphical symbols
for diagrams.
* See web site address on title page.

INTERNATIONAL
IEC
STANDARD
60068-2-21
Fifth edition
1999-01
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 fixation

 IEC 1999  Copyright - all rights reserved
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 the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: [phone] e-mail: [e-mail] IEC web site http://www.iec.ch
Commission Electrotechnique Internationale
PRICE CODE
U
International Electrotechnical Commission
For price, see current catalogue

– 2 – 60068-2-21 © IEC:1999(E)

CONTENTS
Page
FOREWORD . 4

Clause
1 Scope. 5

2 Normative references. 5

3 Test Ua : tensile . 6
3.1 Object. 6
3.2 General description. 6
3.3 Preconditioning. 6
3.4 Initial measurements. 6
3.5 Test method . 6
3.6 Final measurements . 7
3.7 Information to be given in the relevant specification. 7
4 Test Ua : thrust . 8
4.1 Object. 8
4.2 General description. 8
4.3 Preconditioning. 8
4.4 Initial measurements. 8
4.5 Test method . 8
4.6 Final measurements . 9
4.7 Information to be given in the relevant specification. 9
5 Test Ub: bending . 10
5.1 Object. 10
5.2 General description. 10
5.3 Preconditioning. 10
5.4 Initial measurements. 10
5.5 Test method . 11
5.6 Final measurements . 13
5.7 Information to be given in the relevant specification. 13
6 Test Uc: torsion . 14

6.1 Object. 14
6.2 Preconditioning . 14
6.3 Initial measurements. 14
6.4 Test method. 14
6.5 Final measurements. 15
6.6 Information to be given in the relevant specification. 15
7 Test Ud: torque. 15
7.1 Object. 15
7.2 General description. 15
7.3 Preconditioning. 15
7.4 Initial measurements. 15

60068-2-21 © IEC:1999(E) – 3 –

Clause Page
7.5 Test method . 15

7.6 Final measurements . 16

7.7 Information to be given in the relevant specification. 16

8 Test Ue: robustness of terminations for SMD in the mounted state . 17

8.1 Object. 17

8.2 General description. 17

8.3 Mounting. 18

8.4 Initial measurements. 19

8.5 Test methods. 19
8.6 Final measurements . 21
8.7 Information to be given in the relevant specification. 22

– 4 – 60068-2-21 © IEC:1999(E)

INTERNATIONAL ELECTROTECHNICAL COMMISSION

___________
ENVIRONMENTAL TESTING –
Part 2-21: Tests –
Test U: Robustness of terminations and integral mounting devices

FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The 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 50:
Environmental testing, and is published by IEC technical committee 91: Surface mounting
technology.
This fifth edition cancels and replaces the fourth edition, published in 1983, and its
Amendments 1, 2 and 3 published in 1985, 1991 and 1992, respectively, and constitutes a
technical revision.
The text of this edition is based on the following documents.
FDIS Report on voting
91/156/FDIS 91/163/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.

60068-2-21 © IEC:1999(E) – 5 –

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.
Table 1 provides details of the applicable tests.
Table 1 – Application
Test Type Component Mounted/
not mounted
Ua Tensile Leaded devices Not mounted
Ua Thrust Leaded devices Not mounted
Ub Bending Leaded devices Not mounted
Uc Torsion Leaded devices Not mounted
Ud Torque Threaded stud or screw termination Not mounted
Ue Bending Surface mounted devices Mounted
Ue Pull/push Surface mounted devices Mounted
Ue Shear Surface mounted devices Mounted
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 60068. At the time of publication, the editions indicated
were valid. All normative documents are subject to revision, and parties to agreements based
on this part of IEC 60068 are encouraged to investigate the possibility of applying the most
recent editions of the normative documents indicated below. Members of IEC and ISO maintain

registers of currently valid International Standards.
IEC 60068-1:1988, Environmental testing – Part 1: General and guidance
IEC 60068-2-20:1979, Environmental testing – Part 2: Tests – Test T: Soldering
IEC 60068-2-61:1991, Environmental testing – Part 2: Tests – Test Z/ABDM: Climatic sequence
IEC 60249-2-4:1987, Base materials for printed circuits – Part 2 : Specifications – Specification
No. 4: Epoxy woven glass fibre copper-clad laminated sheet, general purpose grade
IEC 61191-2: — Printed board assemblies – Part 2: Sectional specification – Surface mount
1)
soldered assemblies
___________
1)
To be published.
– 6 – 60068-2-21 © IEC:1999(E)

ISO 31-3:1992, Quantities and units – Part 3: Mechanics

ISO 272:1982, Fasteners – Hexagon products – Widths across flats

ISO 9453:1990, Soft solder alloys – Chemical compositions and forms

3 Test Ua : tensile
This test is applicable to all types of terminations.

3.1 Object
The purpose of this test is to verify that the terminations and attachment of the terminations to
the body of the component will withstand such axial stresses as are likely to be applied during
normal assembly or handling operations.
3.2 General description
With the termination in its normal position and the component held by its body, a force is
applied to the termination in the direction of its axis and
...

NORME CEI
INTERNATIONALE IEC
60068-2-21
INTERNATIONAL
Cinquième édition
STANDARD
Fifth edition
1999-01
Essais d’environnement –
Partie 2-21:
Essais – Essai U: Robustesse des sorties
et des dispositifs de montage incorporés
Environmental testing –
Part 2-21:
Tests – Test U: Robustness of terminations
and integral mounting devices
Numéro de référence
Reference number
CEI/IEC 60068-2-21:2001
Numérotation des publications Publication numbering

Depuis le 1er janvier 1997, les publications de la CEI As from 1 January 1997 all IEC publications are

sont numérotées à partir de 60000. Ainsi, la CEI 34-1 issued with a designation in the 60000 series. For
devient la CEI 60034-1. example, IEC 34-1 is now referred to as IEC 60034-1.

Editions consolidées Consolidated editions

Les versions consolidées de certaines publications de la The IEC is now publishing consolidated versions of its

CEI incorporant les amendements sont disponibles. Par publications. For example, edition numbers 1.0, 1.1
exemple, les numéros d’édition 1.0, 1.1 et 1.2 indiquent and 1.2 refer, respectively, to the base publication,
respectivement la publication de base, la publication de the base publication incorporating amendment 1 and

base incorporant l’amendement 1, et la publication de the base publication incorporating amendments 1
base incorporant les amendements 1 et 2. and 2.
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NORME CEI
INTERNATIONALE IEC
60068-2-21
INTERNATIONAL
Cinquième édition
STANDARD
Fifth edition
1999-01
Essais d’environnement –
Partie 2-21:
Essais – Essai U: Robustesse des sorties
et des dispositifs de montage incorporés
Environmental testing –
Part 2-21:
Tests – Test U: Robustness of terminations
and integral mounting devices
 IEC 2001 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun procédé, any form or by any means, electronic or mechanical,
électronique ou mécanique, y compris la photocopie et les including photocopying and microfilm, without permission in
microfilms, sans l'accord écrit de l'éditeur. writing from the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: [phone] e-mail: [e-mail] IEC web site http://www.iec.ch
CODE PRIX
Commission Electrotechnique Internationale
U
PRICE CODE
International Electrotechnical Commission
Pour prix, voir catalogue en vigueur
For price, see current catalogue

– 2 – 60068-2-21 © CEI:1999
SOMMAIRE
AVANT-PROPOS . 6

1 Domaine d’application. 8

2 Références normatives . 8

3Essai Ua : traction . 10
3.1 Objet. 10
3.2 Description générale. 10
3.3 Préconditionnement . 10
3.4 Mesures initiales. 10
3.5 Méthode d’essai. 10
3.6 Mesures finales . 12
3.7 Renseignements à donner dans la spécification particulière . 12
4Essai Ua poussée . 12
2:
4.1 Objet. 12
4.2 Description générale. 12
4.3 Préconditionnement . 14
4.4 Mesures initiales. 14
4.5 Méthode d’essai. 14
4.6 Mesures finales . 16
4.7 Renseignements à donner dans la spécification particulière . 16
5 Essai Ub: pliage. 16
5.1 Objet. 16
5.2 Description générale. 16
5.3 Préconditionnement . 18
5.4 Mesures initiales. 18
5.5 Méthode d’essai. 18
5.6 Mesures finales . 22
5.7 Renseignements à donner dans la spécification particulière . 22
6 Essai Uc: torsion. 22
6.1 Objet. 22
6.2 Préconditionnement . 22

6.3 Mesures initiales. 24
6.4 Méthode d’essai. 24
6.5 Mesures finales . 24
6.6 Renseignements à donner dans la spécification particulière . 24
7 Essai Ud: couple. 26
7.1 Objet. 26
7.2 Description générale. 26
7.3 Préconditionnement . 26
7.4 Mesures initiales. 26
7.5 Méthode d’essai. 26
7.6 Mesures finales . 28
7.7 Renseignements à donner dans la spécification particulière . 28

60068-2-21 © IEC:1999 – 3 –
CONTENTS
FOREWORD . 7

1 Scope . 9

2 Normative references. 9

3Test Ua : tensile . 11
3.1 Object. 11
3.2 General description. 11
3.3 Preconditioning. 11
3.4 Initial measurements. 11
3.5 Test method. 11
3.6 Final measurements . 13
3.7 Information to be given in the relevant specification . 13
4Test Ua : thrust. 13
4.1 Object. 13
4.2 General description. 13
4.3 Preconditioning. 15
4.4 Initial measurements. 15
4.5 Test method. 15
4.6 Final measurements . 17
4.7 Information to be given in the relevant specification . 17
5 Test Ub: bending . 17
5.1 Object. 17
5.2 General description. 17
5.3 Preconditioning. 19
5.4 Initial measurements. 19
5.5 Test method. 19
5.6 Final measurements . 23
5.7 Information to be given in the relevant specification . 23
6 Test Uc: torsion . 23
6.1 Object. 23
6.2 Preconditioning. 23

6.3 Initial measurements. 25
6.4 Test method.
...