Environmental testing - Part 2-82: Tests - Test Xw1: Whisker test methods for components and parts used in electronic assemblies

This part of IEC 60068 specifies tests for the whiskering propensity of surface finishes of
electric or electronic components and mechanical parts such as punched/stamped parts (for
example, jumpers, electrostatic discharge protection shields, mechanical fixations, press-fit
pins and other mechanical parts used in electronic assemblies) representing the finished
stage, with tin or tin-alloy finish. Changes of the physical dimensions of mould compounds,
plastics and the like during the required test flow are not considered or assessed. The test
methods have been developed by using a knowledge-based approach.
This document can also be used at sub-suppliers, like plating shops, stamping shops or other
service providers to ensure a consistent surface quality within the supply chain.
These test methods are employed with defined acceptance criteria by a relevant component
or application specification.
The tests described in this document are applicable for initial qualification, for periodic
monitoring in accordance with Clause 7, and for changes of technology or manufacturing
processes of existing surfaces in accordance with Clause 9.
The mating area of connectors is not covered by this test method. IEC 60512-16-21 applies
for the mating areas of connectors.

Umgebungseinflüsse - Teil 2-82: Prüfungen - Prüfung XW1: Whisker-Prüfverfahren für elektronische und elektrische Bauelemente

Essais d’environnement - Partie 2-82: Essais - Essai XW1: Méthodes de vérification des trichites pour les composants électroniques et électriques

L'IEC 60068-2-82:2019 spécifie des essais de vérification de la propension au développement des trichites pour les finis de surface des composants électriques ou électroniques et des pièces mécaniques comme les pièces embouties/estampées (par exemple cavaliers, écrans de protection contre les décharges électrostatiques, fixations mécaniques, contacts insérés à force et autres pièces mécaniques utilisées dans les ensembles électroniques) qui représentent la phase de finition, avec un fini en étain ou en alliage d'étain. Les modifications des dimensions physiques des composants moulés, des plastiques et autres pendant le flux d'essai exigé ne sont pas prises en compte ni évaluées. Les méthodes d'essai ont été mises au point en utilisant une approche fondée sur la connaissance. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: – extension du domaine d'application de la norme d'essai des composants électroniques aux composants électromécaniques et aux contacts insérés à force qui sont utilisés pour la technologie d'assemblage et d'interconnexion; – réduction significative de l'effort d'essai par une sélection de conditions d'essai fondée sur la connaissance, c'est-à-dire que les essais non applicables à un système de matériaux donné peuvent être omis (voir Annexe D); – harmonisation avec la JESD 201A par omission des sévérités M et N pour les essais de cycle thermique; – réduction considérable de la durée d'essai (1 000 h au lieu de 4 000 h) pour l'essai de chaleur humide par l'introduction d'une condition d'essai à humidité élevée de 85 % H.R. et d'une température de 85 °C assurant une plus grande sévérité.

Okoljsko preskušanje - 2-82. del: Preskusi - Preskus Xw1: Preskusna metoda za nitke v komponentah pri elektronskih sestavih

Ta del standarda IEC 60068 določa preskuse nagnjenosti k tvorjenju vlaknastih kristalov, ki se lahko pojavijo na prevlekah električnih ali elektronskih komponent in mehanskih delov, kot so vgravirani/vtisnjeni deli (na primer povezovalni vodi, zaščite pred elektrostatičnimi razelektritvami, mehanske pritrditve, zatič za pritrditev s pritiskom ter drugi mehanski deli, ki se uporabljajo v elektronskih sklopih) in predstavljajo zaključno fazo, s prevleko iz kositra ali kositrove zlitine. Spremembe fizičnih mer kalupnih mas, polimerov in podobnega med zahtevanim preskušanjem niso obravnavane ali ocenjene. Preskusne metode so bile razvite z na znanju temelječim pristopom.
Ta dokument lahko uporabljajo tudi poddobavitelji, na primer delavnice za prevleke, delavnice za vtiskavanje ali drugi ponudniki storitev za zagotavljanje enakomerne kakovosti površine v oskrbovalni verigi.
Te preskusne metode se uporabljajo z opredeljenimi kriteriji sprejemljivosti, če jih predpisuje ustrezna specifikacija komponente ali uporabe.
Preskusi, ki so opisani v tem dokumentu, se uporabljajo za temeljno kvalifikacijo, redno spremljanje skladno s točko 7 in za spremembe v tehnologiji ali proizvodnih postopkih obstoječih površin skladno s točko 9.
Ta preskusna metoda ne zajema priključnega dela konektorjev. Za priključne dele konektorjev se uporablja IEC 60512-16-21.

General Information

Status
Published
Publication Date
08-Aug-2019
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
22-Jul-2019
Due Date
26-Sep-2019
Completion Date
09-Aug-2019

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SLOVENSKI STANDARD
SIST EN IEC 60068-2-82:2019
01-september-2019
Nadomešča:
SIST EN 60068-2-82:2007
Okoljsko preskušanje - 2-82. del: Preskusi - Preskus Xw1: Preskusna metoda za
nitke v komponentah pri elektronskih sestavih
Environmental testing - Part 2-82: Tests - Test Xw1: Whisker test methods for
components and parts used in electronic assemblies

Umgebungseinflüsse - Teil 2-82: Prüfungen - Prüfung XW1: Whisker-Prüfverfahren für

elektronische und elektrische Bauelemente

Essais d’environnement - Partie 2-82: Essais - Essai XW1: Méthodes de vérification des

trichites pour les composants électroniques et électriques
Ta slovenski standard je istoveten z: EN IEC 60068-2-82:2019
ICS:
19.040 Preskušanje v zvezi z Environmental testing
okoljem
31.190 Sestavljeni elektronski Electronic component
elementi assemblies
SIST EN IEC 60068-2-82:2019 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 60068-2-82:2019
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SIST EN IEC 60068-2-82:2019
EUROPEAN STANDARD EN IEC 60068-2-82
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2019
ICS 19.040 Supersedes EN 60068-2-82:2007
English Version
Environmental testing - Part 2-82: Tests - Test Xw1: Whisker test
methods for components and parts used in electronic
assemblies
(IEC 60068-2-82:2019)

Essais d'environnement - Partie 2-82: Essais - Essai Xw1: Umgebungseinflüsse - Teil 2-82: Prüfungen - Prüfung XW1:

Méthodes de vérification des trichites pour les composants Whisker-Prüfverfahren für Bauelemente und Teile in

et les pièces utilisés dans les ensembles électroniques elektronischen Baugruppen

(IEC 60068-2-82:2019) (IEC 60068-2-82:2019)

This European Standard was approved by CENELEC on 2019-06-18. 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,

Turkey 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

© 2019 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Ref. No. EN IEC 60068-2-82:2019 E
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SIST EN IEC 60068-2-82:2019
EN IEC 60068-2-82:2019 (E)
European foreword

The text of document 91/1562/FDIS, future edition 2 of IEC 60068-2-82, prepared by IEC/TC 91 "Electronics

assembly technology" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as

EN IEC 60068-2-82:2019.
The following dates are fixed:

• latest date by which the document has to be implemented at national level by (dop) 2020-03-18

publication of an identical national standard or by endorsement

• latest date by which the national standards conflicting with the (dow) 2022-06-18

document have to be withdrawn
This document supersedes EN 60068-2-82:2007.

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.

Endorsement notice

The text of the International Standard IEC 60068-2-82:2019 was approved by CENELEC as a European

Standard without any modification.

In the official version, for Bibliography, the following notes have to be added for the standards indicated:

IEC 61191-1 NOTE Harmonized as EN IEC 61191-1
IEC 61249-2-7 NOTE Harmonized as EN 61249-2-7
IEC 61249-2-22 NOTE Harmonized as EN 61249-2-22
IEC 61249-2-35 NOTE Harmonized as EN 61249-2-35
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SIST EN IEC 60068-2-82:2019
EN IEC 60068-2-82:2019 (E)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following documents are referred to in the text in such a way that some or all of their content constitutes

requirements of this document. For dated references, only the edition cited applies. For undated references, the

latest edition of the referenced document (including any amendments) applies.

NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies.

NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here: www.cenelec.eu.

Publication Year Title EN/HD Year
IEC 60068-1 2013 Environmental testing - Part 1: General and EN 60068-1 2014
guidance

IEC 60068-2-14 2009 Environmental testing - Part 2-14: Tests - Test EN 60068-2-14 2009

N: Change of temperature

IEC 60068-2-20 - Environmental testing - Part 2-20: Tests - Test EN 60068-2-20 -

T: Test methods for solderability and
resistance to soldering heat of devices with
leads

IEC 60068-2-58 - Environmental testing - Part 2-58: Tests - Test EN 60068-2-58 -

Td: Test methods for solderability, resistance
to dissolution of metallization and to soldering
heat of surface mounting devices (SMD)

IEC 60068-2-67 - Environmental testing - Part 2-67: Tests - Test EN 60068-2-67 -

Cy: Damp heat, steady state, accelerated test
primarily intended for components

IEC 60068-2-78 - Environmental testing - Part 2-78: Tests - Test EN 60068-2-78 -

Cab: Damp heat, steady state

IEC 60512-16-21 2012 Connectors for electronic equipment - Tests EN 60512-16-21 2012

and measurements - Part 16-21: Mechanical
tests on contacts and terminations - Test 16u:
Whisker test via the application of external
mechanical stresses
IEC 61192-3 2002 Workmanship requirements for soldered EN 61192-3 2003
electronic assemblies - Part 3: Through-hole
mount assemblies
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SIST EN IEC 60068-2-82:2019
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SIST EN IEC 60068-2-82:2019
IEC 60068-2-82
Edition 2.0 2019-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Environmental testing –
Part 2-82: Tests – Test Xw : Whisker test methods for components and parts
used in electronic assemblies
Essais d'environnement –
Partie 2-82: Essais – Essai Xw : Méthodes de vérification des trichites
pour les composants et les pièces utilisés dans les ensembles électroniques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 19.040 ISBN 978-2-8322-6863-6

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: 7 ----------------------
SIST EN IEC 60068-2-82:2019
– 2 – IEC 60068-2-82:2019 © IEC 2019
CONTENTS

FOREWORD ........................................................................................................................... 4

1 Scope .............................................................................................................................. 6

2 Normative references ...................................................................................................... 6

3 Terms and definitions ...................................................................................................... 7

4 Test equipment ................................................................................................................ 9

4.1 General ................................................................................................................... 9

4.2 Desiccator .............................................................................................................. 9

4.3 Humidity chamber ................................................................................................... 9

4.4 Thermal cycling chamber ........................................................................................ 9

4.5 Equipment for visual inspection ............................................................................... 9

4.5.1 Scanning electron microscope ......................................................................... 9

4.5.2 Optical microscope/Confocal laser microscope ................................................ 9

4.6 Fixing jig ................................................................................................................. 9

5 Preparation for test ........................................................................................................ 10

5.1 Selection of relevant tests ..................................................................................... 10

5.1.1 General ......................................................................................................... 10

5.1.2 Storage conditions prior to testing ................................................................. 11

5.1.3 Pre-aging (storage in the supply chain) before testing ................................... 12

5.2 Handling of the specimens .................................................................................... 12

5.3 Sample size .......................................................................................................... 12

5.4 Surface and base materials for test selection ........................................................ 12

5.5 Preconditioning of test specimen not intended for soldering/welding ..................... 13

5.5.1 Preconditioning of test specimen intended for press-fit applications ............... 13

5.5.2 Preconditioning of test specimen intended for mechanical loads other

than press fit ................................................................................................. 14

5.6 Preconditioning of test specimen intended for soldering/welding ........................... 14

5.6.1 General ......................................................................................................... 14

5.6.2 Mechanical pretreatment ............................................................................... 14

5.6.3 Heat pre-treatment ........................................................................................ 15

6 Test conditions .............................................................................................................. 15

6.1 General ................................................................................................................. 15

6.2 Ambient test .......................................................................................................... 15

6.3 Damp heat test ..................................................................................................... 15

6.4 Temperature cycling test ....................................................................................... 16

6.5 Ambient test for press-fit applications ................................................................... 16

7 Monitoring and technological similarity .......................................................................... 17

7.1 Monitoring ............................................................................................................. 17

7.2 Technological similarity ......................................................................................... 17

8 Test and assessment ..................................................................................................... 18

8.1 Whisker investigation ............................................................................................ 18

8.2 Initial measurement .............................................................................................. 18

8.3 Test ...................................................................................................................... 18

8.4 Recovery .............................................................................................................. 18

8.5 Intermediate or final assessment for each test condition ....................................... 18

8.5.1 Fixed threshold length for pass/fail classification ........................................... 18

8.5.2 Statistical assessment of whisker lengths ...................................................... 19

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SIST EN IEC 60068-2-82:2019
IEC 60068-2-82:2019 © IEC 2019 – 3 –

9 Technology or manufacturing process changes ............................................................. 19

10 Content of final report .................................................................................................... 20

Annex A (normative) Measurement of whisker length ........................................................... 22

Annex B (informative) Examples of whiskers ........................................................................ 23

Annex C (informative) Guidance on acceptance criteria ....................................................... 25

C.1 Risks attributed to whiskers .................................................................................. 25

C.2 Acceptance criteria for whisker length ................................................................... 25

C.3 Acceptance criteria for whisker density ................................................................. 26

C.4 Statistical evaluation of number and length of whiskers......................................... 26

C.5 Example of statistic evaluation .............................................................................. 26

Annex D (informative) Technical background of whisker growth ........................................... 29

Annex E (normative) Transition scenarios for the changeover of the damp-heat test

conditions ............................................................................................................................. 30

Bibliography .......................................................................................................................... 32

Figure 1 – Cross-sectional views of component termination surface finishes ........................... 8

Figure 2 – Selection of test methods ..................................................................................... 11

Figure 3 – .......................................... 14
Flow for treatment and/or bending and heat treatment

Figure A.1 – Estimation of whisker length ............................................................................. 22

Figure A.2 – Example for whisker length measurement ......................................................... 22

Figure B.1 – Nodule .............................................................................................................. 23

Figure B.2 – Column whisker ................................................................................................ 23

Figure B.3 – Filament whisker ............................................................................................... 24

Figure B.4 – Kinked whisker ................................................................................................. 24

Figure B.5 – Spiral whisker ................................................................................................... 24

Figure C.1 – Smallest distance of components and circuit boards ......................................... 25

Figure C.2 – Histogram of whisker lengths and fitted log-normal distribution ......................... 27

Figure C.3 – Histogram of whisker lengths and fitted log-normal distribution ......................... 28

Figure C.4 – Histogram of whisker lengths and fitted log-normal distribution ......................... 28

Figure E.1 –Transition paths for damp-heat testing of components ....................................... 30

Table 1 – Material systems recognized for effective whisker mitigation ................................. 13

Table 2 –
Preconditioning conditions and test legs for components for different

............................................................................................................. 15

assembly processes

Table 3 – Conditions for the ambient test .............................................................................. 15

Table 4 – Conditions for the damp heat test .......................................................................... 16

Table 5 – Conditions for the ambient test .............................................................................. 16

Table 6 – Conditions for the ambient test applicable to press-fit terminations ........................ 17

Table 7 – Classification for measured whisker length ............................................................ 19

Table 8 – Surface finish technology and manufacturing process change acceptance

parameters ........................................................................................................................... 19

Table 9 – Final report ............................................................................................................ 21

Table C.1 – Classification for measured whisker length ........................................................ 27

Table E.1 – Conclusion matrix for parallel damp heat testing ................................................ 31

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SIST EN IEC 60068-2-82:2019
– 4 – IEC 60068-2-82:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ENVIRONMENTAL TESTING –
Part 2-82: Tests – Test Xw1: Whisker test methods for components
and parts used in electronic assemblies
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 60068-2-82 has been prepared by IEC technical committee 91:

Electronics assembly technology.

This second edition cancels and replaces the first edition published in 2007. This edition

constitutes a technical revision.

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

edition:

– extension of the scope of the test standard from electronic to electromechanic components

and press-fit pins, which are used for assembly and interconnect technology;

– significant reduction of the testing effort by a knowledge-based selection of test conditions

i.e. tests not relevant for a given materials system can be omitted (see Annex D);

– harmonization with JESD 201A by omission of severities M, N for temperature cycling

tests;
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SIST EN IEC 60068-2-82:2019
IEC 60068-2-82:2019 © IEC 2019 – 5 –

– highly reduced test duration (1 000 h instead of 4 000 h) for damp-heat test by introducing

test condition at elevated humidity of 85 % R.H. and a temperature of 85 °C providing

increased severity.
The text of this International Standard is based on the following documents:
FDIS Report on voting
91/1562/FDIS 91/1573/RVD

Full information on the voting for the approval of this International Standard can be found in

the report on voting indicated in the above table.

A list of all parts in the IEC 60068 series, published under the general title Environmental

testing, can be found on the IEC website.

This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

The committee has decided that the contents of this document will remain unchanged until the

stability date indicated on the IEC website under "http://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.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates

that it contains colours which are considered to be useful for the correct

understanding of its contents. Users should therefore print this document using a

colour printer.
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SIST EN IEC 60068-2-82:2019
– 6 – IEC 60068-2-82:2019 © IEC 2019
ENVIRONMENTAL TESTING –
Part 2-82: Tests – Test Xw1: Whisker test methods for components
and parts used in electronic assemblies
1 Scope

This part of IEC 60068 specifies tests for the whiskering propensity of surface finishes of

electric or electronic components and mechanical parts such as punched/stamped parts (for

example, jumpers, electrostatic discharge protection shields, mechanical fixations, press-fit

pins and other mechanical parts used in electronic assemblies) representing the finished

stage, with tin or tin-alloy finish. Changes of the physical dimensions of mould compounds,

plastics and the like during the required test flow are not considered or assessed. The test

methods have been developed by using a knowledge-based approach.

This document can also be used at sub-suppliers, like plating shops, stamping shops or other

service providers to ensure a consistent surface quality within the supply chain.

These test methods are employed with defined acceptance criteria by a relevant component

or application specification.

The tests described in this document are applicable for initial qualification, for periodic

monitoring in accordance with Clause 7, and for changes of technology or manufacturing

processes of existing surfaces in accordance with Clause 9.

The mating area of connectors is not covered by this test method. IEC 60512-16-21 applies

for the mating areas of connectors.
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 60068-2-14:2009, Environmental testing – Part 2-14: Tests – Test N: Change of

temperature

IEC 60068-2-20, Environmental testing – Part 2-20: Tests – Test T: Test methods for

solderability and resistance to soldering heat of devices with leads

IEC 60068-2-58, 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 60068-2-67, Environmental testing – Part 2-67: Tests – Test Cy: Damp heat, steady state,

accelerated test primarily intended for components

IEC 60068-2-78, Environmental testing – Part 2-78: Tests – Test Cab: Damp heat, steady

state
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SIST EN IEC 60068-2-82:2019
IEC 60068-2-82:2019 © IEC 2019 – 7 –

IEC 61192-3:2002, Workmanship requirements for soldered electronic assemblies – Part 3:

Through-hole mount assemblies

IEC 60512-16-21:2012, Connectors for electronic equipment – Tests and measurements –

Part 16-21: Mechanical tests on contacts and terminations – Test 16u: Whisker test via the

application of external mechanical stresses
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
whisker
metallic protrusion that grows spontaneously during storage or use

Note 1 to entry: Whiskers typically do not require any electrical field for their growth and are not to be confused

with products of electrochemical migration. Signs of whiskers include:
– striations in growth direction;
– typically no branching;
– typically constant diameters.
Exceptions are known, but are rare and can require detailed investigation.
For the purposes of this document, whiskers are considered if:
– they have an aspect ratio (length/width) greater than 2;
– they have a length of 10 µm or more.

Note 2 to entry: For the purposes of this document, whiskers have the following characteristics

(see also Annex B):

– they can be kinked, bent, or twisted; they usually have a uniform cross-sectional shape;

– they may have rings around the circumference of the column.

Note 3 to entry: Whiskers are not to be confused with dendrites, which are fern-like growths on the surface of a

material, which can be formed as a result of electro(chemical)-migration of an ionic species or produced during

solidification.

Note 4 to entry: Whiskers are not to be confused with slivers as generated by mechanical metal processing.

Whiskers are not to be confused with tubular SnO structures, which may develop under damp-heat test conditions.

These structures are hollow and are typically lacking striations occurring on Sn whiskers.

3.2
termination
solderable element of a component consisting of the following elements
– base material;

– underlayer (or underlayer system, if more than one underlayer is present), if any, located

under the final plating;
– final tin or tin alloy finish
___________
Withdrawn publication.
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SIST EN IEC 60068-2-82:2019
– 8 – IEC 60068-2-82:2019 © IEC 2019
SEE: Figure 1
a) Gull wing termination b) Chip termination
Key
a base material
...

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