Test methods for electrical materials, printed board and other interconnection structures and assemblies - Part 5-503: General test method for materials and assemblies - Conductive anodic filaments (CAF) testing of circuit boards

IEC 61189-5-503:2017 specifies the conductive anodic filament (hereafter referred to as CAF) and specifies not only the steady-state temperature and humidity test, but also a temperature-humidity cyclic test and an unsaturated pressurized vapour test (HAST).

Méthodes d’essai pour les matériaux électriques, les cartes imprimées et autres structures d’interconnexion et ensembles - Partie 5-503: Méthode d’essai générale pour les matériaux et les assemblages – Essais des filaments anodiques conducteurs (CAF) des cartes à circuits

L’IEC 61189-5-503:2017 spécifie le filament anodique conducteur (ci-après appelé CAF) et spécifie non seulement l’essai continu de température et d’humidité, mais aussi un essai cyclique de température-humidité et un essai de vapeur pressurisée non saturée (HAST).

General Information

Status
Published
Publication Date
21-May-2017
Current Stage
PPUB - Publication issued
Start Date
22-May-2017
Completion Date
22-May-2017
Ref Project

Buy Standard

Standard
IEC 61189-5-503:2017 - Test methods for electrical materials, printed board and other interconnection structures and assemblies - Part 5-503: General test method for materials and assemblies - Conductive anodic filaments (CAF) testing of circuit boards
English and French language
47 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

IEC 61189-5-503
Edition 1.0 2017-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Test methods for electrical materials, printed board and other interconnection
structures and assemblies –
Part 5-503: General test method for materials and assemblies – Conductive
anodic filaments (CAF) testing of circuit boards
Méthodes d’essai pour les matériaux électriques, les cartes imprimées et autres
structures d’interconnexion et ensembles –
Partie 5-503: Méthode d’essai générale pour les matériaux et les assemblages –
Essais des filaments anodiques conducteurs (CAF) des cartes à circuits
IEC 61189-5-503:2017-05(en-fr)
---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
Copyright © 2017 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 Electropedia - www.electropedia.org

The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,

variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English

committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.

and withdrawn publications. Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary

details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and

once a month by email. French extracted from the Terms and Definitions clause of

IEC publications issued since 2002. Some entries have been

IEC Customer Service Centre - webstore.iec.ch/csc collected from earlier publications of IEC TC 37, 77, 86 and

If you wish to give us your feedback on this publication or CISPR.
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 - Electropedia - www.electropedia.org

webstore.iec.ch/advsearchform Le premier dictionnaire d'électrotechnologie en ligne au

La recherche avancée permet de trouver des publications IEC monde, avec plus de 22 000 articles terminologiques en

en utilisant différents critères (numéro de référence, texte, anglais et en français, ainsi que les termes équivalents dans

comité d’études,…). Elle donne aussi des informations sur les 16 langues additionnelles. Egalement appelé Vocabulaire

projets et les publications remplacées ou retirées. Electrotechnique International (IEV) en ligne.

IEC Just Published - webstore.iec.ch/justpublished Glossaire IEC - std.iec.ch/glossary

Restez informé sur les nouvelles publications IEC. Just 67 000 entrées terminologiques électrotechniques, en anglais

Published détaille les nouvelles publications parues. et en français, extraites des articles Termes et Définitions des

Disponible en ligne et une fois par mois par email. publications IEC parues depuis 2002. Plus certaines entrées

antérieures extraites des publications des CE 37, 77, 86 et
Service Clients - webstore.iec.ch/csc CISPR de l'IEC.
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
sales@iec.ch.
---------------------- Page: 2 ----------------------
IEC 61189-5-503
Edition 1.0 2017-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Test methods for electrical materials, printed board and other interconnection
structures and assemblies –
Part 5-503: General test method for materials and assemblies – Conductive
anodic filaments (CAF) testing of circuit boards
Méthodes d’essai pour les matériaux électriques, les cartes imprimées et autres
structures d’interconnexion et ensembles –
Partie 5-503: Méthode d’essai générale pour les matériaux et les assemblages –
Essais des filaments anodiques conducteurs (CAF) des cartes à circuits
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.180 ISBN 978-2-8322-7362-3

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 61189-5-503:2017  IEC 2017
CONTENTS

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

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

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

3 Terms and definitions ...................................................................................................... 6

4 Testing condition ............................................................................................................. 7

4.1 Standard condition .................................................................................................. 7

4.2 Judgment state ....................................................................................................... 8

5 Specimen ........................................................................................................................ 8

5.1 Outline of CAF test vehicle design .......................................................................... 8

5.1.1 Evaluation design for the glass cloth direction ................................................. 8

5.1.2 Design between plated through hole (PTH) ...................................................... 9

5.2 CAF test board ...................................................................................................... 10

5.2.1 Example A ..................................................................................................... 10

5.2.2 Example B ..................................................................................................... 11

5.3 Number of specimens ........................................................................................... 13

6 Equipment/Apparatus or material ................................................................................... 13

6.1 Environmental test chamber .................................................................................. 13

6.2 Measuring equipment ............................................................................................ 13

6.3 Power supply ........................................................................................................ 13

6.4 Current limiting resistors ....................................................................................... 14

6.5 Connecting wire .................................................................................................... 14

6.6 Other dedicated fixtures ........................................................................................ 14

7 Resistance measurement method .................................................................................. 14

7.1 Manual insulation resistance measurement method .............................................. 14

7.2 Automatic insulation resistance measurement method .......................................... 15

8 Test method .................................................................................................................. 16

8.1 Test method selection ........................................................................................... 16

8.2 Steady-state temperature and humidity test .......................................................... 16

8.2.1 Object ............................................................................................................ 16

8.2.2 Test condition ................................................................................................ 16

8.3 Temperature and humidity (12 h + 12 h) cycle test ................................................ 16

8.3.1 Object ............................................................................................................ 16

8.3.2 Test condition ................................................................................................ 17

8.3.3 Number of cycles of the test .......................................................................... 17

8.4 Temperature and humidity cyclic test with and without low temperature

exposure ............................................................................................................... 17

8.4.1 Object ............................................................................................................ 17

8.4.2 Test condition ................................................................................................ 17

8.5 Steady-state high temperature and high humidity (unsaturated pressurized

vapour) test .......................................................................................................... 17

8.5.1 Object ............................................................................................................ 17

8.5.2 Test condition ................................................................................................ 18

9 Procedure ...................................................................................................................... 18

9.1 Test specimen preparation .................................................................................... 18

9.1.1 General ......................................................................................................... 18

9.1.2 Sample identification ..................................................................................... 18

---------------------- Page: 4 ----------------------
IEC 61189-5-503:2017  IEC 2017 – 3 –

9.1.3 Prescreen for opens and shorts ..................................................................... 18

9.1.4 Cleaning ........................................................................................................ 19

9.1.5 Connecting wire ............................................................................................. 19

9.1.6 Cleaning after attachment .............................................................................. 19

9.1.7 Dry ................................................................................................................ 19

9.2 Precondition .......................................................................................................... 19

9.3 Test procedure ...................................................................................................... 19

9.3.1 Setting of the specimen ................................................................................. 19

9.3.2 Test voltage and measuring voltage .............................................................. 19

9.3.3 Temperature and humidity condition at the start time of the test .................... 20

9.3.4 Measurement ................................................................................................. 20

9.3.5 Procedure in test interruption ......................................................................... 21

9.3.6 End of test ..................................................................................................... 21

9.4 Visual inspection ................................................................................................... 21

9.4.1 General ......................................................................................................... 21

9.4.2 Shape of electrochemical migration ............................................................... 21

Annex A (informative) Forms of electrochemical migration ................................................... 22

A.1 Example of dendrite-shaped migration .................................................................. 22

A.2 CAF (Example of migration along the glass fibre) .................................................. 22

Bibliography .......................................................................................................................... 23

Figure 1 – Schematic of in-line test comb, with possible failure site ........................................ 8

Figure 2 – Schematic of staggered test comb, with possible failure site .................................. 9

Figure 3 – Manhattan distance ................................................................................................ 9

Figure 4 – Schematic section of via pair with bias ................................................................. 10

Figure 5 – Example of inner layer via pads and layer patterns .............................................. 10

Figure 6 – Example of no inner layer via pads and layer patterns .......................................... 10

Figure 7 – Insulation evaluation pattern for through-holes and via holes ............................... 11

Figure 8 – Layouts of the two versions of the CAF test boards .............................................. 12

Figure 9 – Measurement with insulation resistance meter ..................................................... 15

Figure 10 – Temperature and humidity in a test .................................................................... 20

Figure A.1 – Example which is generated on the board surface ............................................ 22

Figure A.2 – Example of CAF ................................................................................................ 22

Table 1 – Dimension of insulation evaluation pattern for through-holes ................................. 11

Table 2 – Test structures A1 through A4 design rules ........................................................... 12

Table 3 – Test structures B1 through B4 design rules ........................................................... 13

Table 4 – Test condition ........................................................................................................ 16

Table 5 – Number of cycles of the test .................................................................................. 17

Table 6 – Test condition ........................................................................................................ 17

Table 7 – Test condition (IEC 60068-2-66) ............................................................................ 18

---------------------- Page: 5 ----------------------
– 4 – IEC 61189-5-503:2017  IEC 2017
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
TEST METHODS FOR ELECTRICAL MATERIALS, PRINTED BOARD
AND OTHER INTERCONNECTION STRUCTURES AND ASSEMBLIES –
Part 5-503: General test method for materials and assemblies –
Conductive anodic filaments (CAF) testing of circuit boards
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 61189-5-503 been prepared by IEC technical committee 91:

Electronics assembly technology.

This bilingual version (2019-09) corresponds to the monolingual English version, published in

2017-05.
The text of this standard is based on the following documents:
FDIS Report on voting
91/1433/FDIS 91/1443/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.
---------------------- Page: 6 ----------------------
IEC 61189-5-503:2017  IEC 2017 – 5 –
The French version of this standard has not been voted upon.

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

A list of all parts in the IEC 61189 series, published under the general title Test methods for

electrical materials, printed boards and other interconnection structures and assemblies, 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 "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.
---------------------- Page: 7 ----------------------
– 6 – IEC 61189-5-503:2017  IEC 2017
TEST METHODS FOR ELECTRICAL MATERIALS, PRINTED BOARD
AND OTHER INTERCONNECTION STRUCTURES AND ASSEMBLIES –
Part 5-503: General test method for materials and assemblies –
Conductive anodic filaments (CAF) testing of circuit boards
1 Scope

This part of IEC 61189 specifies the conductive anodic filament (hereafter referred to as CAF)

and specifies not only the steady-state temperature and humidity test, but also a temperature-

humidity cyclic test and an unsaturated pressurized vapour test (HAST).
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 60068-2-30, Environmental testing – Part 2-30: Tests – Test Db: Damp heat, cyclic

(12 h + 12 h cycle)
IEC 60068-2-38, Environmental testing – Part 2-38: Tests – Test Z/AD: Composite
temperature/humidity cyclic test

IEC 60068-2-66, Environmental testing – Part 2: Test methods – Test Cx: Damp heat, steady

state (unsaturated pressurized vapour)

IEC 60068-2-67, Environmental testing – Part 2: 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

IEC 60194, Printed board design, manufacture and assembly – Terms and definitions

IPC-TM-650 No.2.6.14.1, Electrochemical Migration Resistance Test [viewed 2017-01-31].

Available at: https://www.ipc.org/TM/2-6_2-6-14-1.pdf

IPC-TM-650 No.2.6.25, Conductive Anodic Filament (CAF) Resistance Test: X-Y Axis [viewed

2017-01-31]. Available at: https://www.ipc.org/4.0_Knowledge/4.1_Standards/test/2-6-25.pdf

3 Terms and definitions

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

IEC 60068-1 as well as the following apply.

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

addresses:
---------------------- Page: 8 ----------------------
IEC 61189-5-503:2017  IEC 2017 – 7 –
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
electrochemical migration

degradation of insulation characteristics between conductors due to eletrochemical elution of

ions in a humid environment when voltage is applied to conductors of a printed wiring board

Note 1 to entry: In addition, ionic impurities present in the insulations contribute to their degradation.

Note 2 to entry: Electrochemical migration may take the forms of dendrite (3.2) and CAF(3.3).

3.2
dendrite
metal migration

Note 1 to entry: Dendrite is visible in that it creates a branching and tree like structure on the surface, on the

interface between layers, etc. of a printed wiring board.
3.3
CAF
conductive anodic filament

migration which occurs along the monofilament of reinforcing material such as glass cloth in

an inner layer part of a printed wiring board
3.4
HAST
highly accelerated temperature and humidity stress test
stress test under unsaturated pressurized vapour test
Note 1 to entry: See IEC 60068-2-66.
3.5
automatic insulation resistance measurement

measurement to take continuous or predetermined periodic test data using an automatic

measurement system without an operator
3.6
manual insulation resistance measurement

measurement to take predetermined periodic test data using measurement equipment by an

operator

Note 1 to entry: Measurement can be done with or without taking out a specimen from the test chamber.

3.7
test voltage
voltage to apply on the specimen as a stress in the testing environment
3.8
measuring voltage
voltage to apply on the specimen in order to measure the insulation resistance
4 Testing condition
4.1 Standard condition

Measurement is performed under the standard atmospheric condition which is specified in

Clause 4 of IEC 60068-1:2013.
---------------------- Page: 9 ----------------------
– 8 – IEC 61189-5-503:2017  IEC 2017

It depends on a reference condition stated in 4.2 when an ambiguity is found for the judgment

in the standard atmospheric condition or when it is required in particular.

It may be performed under other conditions than the standard atmospheric condition, when no

doubt about the judgment subsits and when measuring in standard condition proves difficult,

or when specified in particular specifications.
4.2 Judgment state

Reference condition is the standard atmospheric condition for measurement as stated in 4.2

of IEC 60068-1:2013.
5 Specimen
5.1 Outline of CAF test vehicle design
5.1.1 Evaluation design for the glass cloth direction

The in-line test combs are comprised of a series of alternate rows of via holes with a voltage

applied across the comb. They represent the most common failure sites where CAF can occur:

between via hole walls. The via holes are in line with one another and in alignment with the

woven glass fibre reinforcement. The closest point between each via pair is the most likely

point for CAF growth (example highlighted in Figure 1). The black spots represent the drilled

hole, and the copper pads associated with the via holes are in orange.

The construction of staggered combs is similar to that of the in-line combs, however, the via

pairs are arranged at 45°. This means that the most likely route for potential CAF growth is

longer since the orientation of the glass fibres may only permit growth in the horizontal and

vertical directions (as represented by the white ellipses in Figure 2).
Fibre weave
IEC
Figure 1 – Schematic of in-line test comb, with possible failure site
---------------------- Page: 10 ----------------------
IEC 61189-5-503:2017  IEC 2017 – 9 –
Fibre weave
IEC
Figure 2 – Schematic of staggered test comb, with possible failure site

"Manhattan distance" is the shortest orthogonal distance along the X- and/or Y- axes lines

between adjacent drilled hole features (corresponds to the orthogonal nature of the laminate

material’s woven glass fibre reinforcement (Figure 3).
''Manhattan distance" = a + b
IEC
Figure 3 – Manhattan distance
5.1.2 Design between plated through hole (PTH)
a) Without inner layer pattern

Example design between PTH without inner layer pattern is shown in Figure 4, which is a

schematic cross-section of a via pair.

NOTE The gap is taken from the edge of the copper. Copper thickness on the hole wall is approximately

50 μm per side.
---------------------- Page: 11 ----------------------
– 10 – IEC 61189-5-503:2017  IEC 2017
IEC
Key
l via pitch
l via to via distance
l via diameter
Figure 4 – Schematic section of via pair with bias
b) With inner layer pattern

There are two designs. One is the design of inner layer via pads and layers as shown in

Figure 5. The other is the design of no inner layer via pads and layer patterns as shown in

Figure 6.
IEC
Figure 5 – Example of inner layer via pads and layer patterns
IEC
Figure 6 – Example of no inner layer via pads and layer patterns
5.2 CAF test board
5.2.1 Example A

This design is based on 5.1. Evaluation of insulation between through-holes is made using the

lattice-like pattern of through-holes as illustrated in Figure 7. The diameter of holes is kept

---------------------- Page: 12 --------
...

Questions, Comments and Discussion

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