IEC 61747-40-6:2018

IEC 61747-40-6 ®
Edition 1.0 2018-02
INTERNATIONAL
STANDARD
colour
inside
Liquid crystal display devices –
Part 40-6: Mechanical testing of display cover glass for mobile devices –
Retained biaxial flexural strength (abraded ring-on-ring)
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.

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 corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 21 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

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and withdrawn publications.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

CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC 61747-40-6 ®
Edition 1.0 2018-02
INTERNATIONAL
STANDARD
colour
inside
Liquid crystal display devices –

Part 40-6: Mechanical testing of display cover glass for mobile devices –

Retained biaxial flexural strength (abraded ring-on-ring)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.120 ISBN 978-2-8322-5339-7

– 2 – IEC 61747-40-6:2018 © IEC 2018
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 General . 7
5 Apparatus . 8
5.1 Testing environment and pre-conditioning . 8
5.2 Abrasion device . 8
5.3 Abrasion material . 10
5.4 Pressurization source . 10
6 Procedure . 10
6.1 Safety . 10
6.1.1 Hazard – Broken glass. 10
6.1.2 Hazard – Airborne particulate . 10
6.2 Sample . 10
6.3 Abrasion testing – Individual specimen . 11
6.4 Complete the report . 11
7 Retained failure load testing . 11
8 Specifications . 11
Annex A (informative)  Check depth measurement . 12
Bibliography . 15

Figure 1 – Abrasion device . 9
Figure 2 – Specimen holder . 10
Figure A.1 – Schematic of fracture surface with measurement of check depth . 12
Figure A.2 – Check depth measurement for grit particle abraded glass – Example 1 . 12
Figure A.3 – Check depth measurement for grit particle abraded glass – Example 2 . 13
Figure A.4 –Check depth measurement for grit particle abraded glass – Example 3 . 13
Figure A.5 –Check depth measurement for grit particle abraded glass – Example 4 . 14

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LIQUID CRYSTAL DISPLAY DEVICES –

Part 40-6: Mechanical testing of display cover glass for mobile devices –
Retained biaxial flexural strength (abraded ring-on-ring)

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 61747-40-6 has been prepared by technical committee 110:
Electronic display devices.
The text of this International Standard is based on the following documents:
CDV Report on voting
110/882/CDV 110/929A/RVC
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.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

– 4 – IEC 61747-40-6:2018 © IEC 2018
A list of all parts in the IEC 61747 series, published under the general title Liquid crystal
display devices, 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.
A bilingual version of this publication may be issued at a later date.

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.
INTRODUCTION
Mobile electronic devices have become increasingly sophisticated and often incorporate
displays for the purposes of user interface and viewing. Such displays commonly incorporate
a transparent cover glass which aids in protecting the display against the introduction of
damage through routine device transport and use, as well as occasional or accidental misuse.
The purpose of this document is to provide mechanical testing procedures for cover glasses
utilized in such applications. Such glasses can be strengthened, for example via an
ion-exchange process, which acts to increase mechanical strength through the introduction of
a surface compressive layer.
– 6 – IEC 61747-40-6:2018 © IEC 2018
LIQUID CRYSTAL DISPLAY DEVICES –

Part 40-6: Mechanical testing of display cover glass for mobile devices –
Retained biaxial flexural strength (abraded ring-on-ring)

1 Scope
This part of IEC 61747 is a mechanical performance testing procedure for cover glass used in
electronic flat panel displays in mobile devices. This document focuses on the measurement
of surface fracture load after flaw introduction via grit particle abrasion. After abrasion, the
retained surface fracture load is measured with the method documented in IEC 61747-40-4.
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 61747-40-1, Liquid crystal display devices – Part 40-1: Mechanical testing of display
cover glass for mobile devices – Guidelines
IEC 61747-40-4, Liquid crystal display devices – Part 40-4: Mechanical testing of display
cover glass for mobile devices – Biaxial flexural strength (ring-on-ring)
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
specimen
individual piece of glass to be abraded and then tested for retained fracture load
3.2
sample
group of specimens that share a common pedigree (such as manufacturing process and
period of production), for which failure statistics can be ge
...