IEC 61747-40-5:2018

Liquid crystal display devices - Part 40-5: Mechanical testing of display cover glass for mobile devices - Strength against dynamic impact by a sharp object with the specimen rigidly supported

IEC 61747-40-5:2018(E) is a mechanical performance testing procedure for cover glass used in electronic displays in mobile devices. This document focuses on the measurement of surface impact energy required to fracture a specimen due to the collision of sharp particles onto the surface of a cover glass. This is achieved by dropping a ball on a sheet of coated abrasives placed on the cover glass, which is rigidly supported. The failure mode is associated with damage introduction via sharp contact. Crack propagation is enhanced by central tension in the case of strengthened glass. This failure mode represents one of several field failure modes observed in mobile devices.

General Information

• Status: Published
• Publication Date: 26-Feb-2018
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 31.120 - Electronic display devices
• Technical Committee: TC 110 - Electronic displays
• Drafting Committee: WG 2 - TC 110/WG 2
• Current Stage: PPUB - Publication issued
• Start Date: 23-Mar-2018
• Completion Date: 27-Feb-2018

Standards Content (Sample)

IEC 61747-40-5 ®
Edition 1.0 2018-02
INTERNATIONAL
STANDARD
colour
inside
Liquid crystal display devices –
Part 40-5: Mechanical testing of display cover glass for mobile devices –
Strength against dynamic impact by a sharp object with the specimen rigidly
supported
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IEC 61747-40-5 ®
Edition 1.0 2018-02
INTERNATIONAL
STANDARD
colour
inside
Liquid crystal display devices –

Part 40-5: Mechanical testing of display cover glass for mobile devices –

Strength against dynamic impact by a sharp object with the specimen rigidly

supported
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.120 ISBN 978-2-8322-5402-8

– 2 – IEC 61747-40-5:2018 © 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 Apparatus overview . 8
5.3 Height adjustment beam . 8
5.4 Base (granite) . 9
5.5 Coated abrasives . 9
5.6 Armature . 9
5.7 Ball release mechanism . 9
5.8 Height adjustment clamp . 9
5.9 Ball release controller . 9
5.10 Ball . 9
5.11 Base . 9
6 Procedure . 10
6.1 Safety . 10
6.1.1 Hazard - Broken glass . 10
6.1.2 Hazard – Compression due to moving ball . 10
6.2 Sample . 10
6.3 Individual specimen . 10
6.4 Complete the report . 11
7 Calculations . 11
7.1 Breaking energy . 11
7.2 Statistical calculations . 11
8 Reporting. 13
8.1 Information to be reported for each test . 13
8.2 Information to be made available upon request . 13
9 Specifications . 13

Figure 1 – Apparatus overview . 8
Figure 2 – Typical Weibull plot . 12

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LIQUID CRYSTAL DISPLAY DEVICES –

Part 40-5: Mechanical testing of display cover glass for mobile devices –
Strength against dynamic impact by a sharp object
with the specimen rigidly supported

FOREWORD
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International Standard IEC 61747-40-5 has been prepared by technical committee 110:
Electronic display devices.
The text of this International Standard is based on the following documents:
FDIS Report on voting
110/936/FDIS 110/958/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.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

– 4 – IEC 61747-40-5:2018 © 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.
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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.
The International Electrotechnical Commission (IEC) draws attention to the fact that it is
claimed that compliance with this document may involve the use of a patent.
IEC takes no position concerning the evidence, validity and scope of this patent right.
The holder of this patent right has assured the IEC that he/she is willing to negotiate licences
either free of charge or under reasonable and non-discriminatory terms and conditions with
applicants throughout the world. In this respect, the statement of the holder of this patent right
is registered with IEC. Information may be obtained from:
Asahi Glass Co., Ltd.
1-5-1Marunouch,Chiyoda-ku, Tokyo, 10-8405 Japan
Attention is drawn to the possibility that some of the elements of this document may be the
subject of patent rights other than those identified above. IEC shall not be held responsible for
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