IEC 62715-6-1:2018

Flexible display devices - Part 6-1: Mechanical test methods - Deformation tests

IEC 62715-6-1:2018 defines the standard test methods to evaluate the mechanical stability of flexible display modules, specifically mechanical stability against deformation, such as bending, rolling, twisting, and stretching. Display modules include displays such as LCD, e-paper, and OLED. This document takes into account, wherever possible, the mechanical test methods outlined under mechanical stress. This second edition cancels and replaces the first edition published in 2014. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) changed the part title to differentiate it from other parts;
b) added new bending testing methods;
c) added detailed testing procedures.

General Information

• Status: Published
• Publication Date: 19-Apr-2018
• ICS: 31.120 - Electronic display devices
• Technical Committee: TC 110 - Electronic displays
• Drafting Committee: WG 8 - TC 110/WG 8
• Current Stage: PPUB - Publication issued
• Start Date: 20-Apr-2018
• Completion Date: 04-May-2018

Relations

• Revises: IEC 62715-6-1:2014 - Flexible display devices - Part 6-1: Mechanical stress test methods
• Effective Date: 05-Sep-2023

Overview

IEC 62715-6-1:2018, "Flexible display devices - Part 6-1: Mechanical test methods - Deformation tests", is an IEC international standard that defines standardized mechanical test methods to evaluate the deformation resistance and mechanical stability of flexible display modules (LCD, e-paper, OLED). This second edition (2018) replaces the 2014 edition and introduces a revised part title, additional bending test methods and more detailed testing procedures. The standard focuses on deformation modes such as bending, rolling, twisting (torsion) and stretching (tension) and requires visual and measured evaluation of panel image quality after testing.

Key topics and technical requirements

• Scope and specimen: Tests apply to the complete display module; final evaluation is based on panel image quality (luminance, chromaticity, uniformity, line defects, point defects).
• Atmospheric conditions: References IEC 62341-5:2009 standard conditions (typically around 25 °C and normal atmospheric pressure). The standard emphasizes that temperature and humidity shall be reported, since these parameters critically affect bending/rolling stability.
• Test methods covered:
  • Cyclic bending test - apparatus, procedure, cycle counts and reporting requirements.
  • Static bending test - displacement/deflection and visual inspection criteria.
  • Combined bending test - combining cyclic and static loads to simulate use conditions.
  • Rolling and static rolling tests - apparatus and procedures for curvature and rollability assessment.
  • Torsion (twisting) test - methods to evaluate twisting resilience.
  • Tension (stretching) test - assess tensile stability of flexible modules.
• Specimen preparation and mounting: Guidance on supports, adhesive bonding (e.g., transfer tape), and preventing unintended stretching during folding.
• Reporting: Test conditions, apparatus configuration, environmental data and post-test image quality metrics must be documented.

Practical applications and who uses this standard

• Display manufacturers use IEC 62715-6-1 for design verification and to qualify flexible LCD, OLED and e‑paper modules for foldable/rollable products.
• R&D and reliability labs apply the deformation tests to compare materials, mechanical designs and protective layers.
• Quality assurance and production testing implement standardized procedures for acceptance testing and failure analysis.
• Buyers, integrators and certification bodies rely on the standard to define contractual test methods and to assess mechanical durability claims for consumer electronics (foldable phones, rollable displays, wearable screens) and industrial flexible displays.

Related standards

• IEC 62341-5:2009 - referenced for environmental (atmospheric) conditions.
• Other parts of the IEC 62715 series - for additional functional, environmental and reliability requirements applicable to flexible display devices.

Keywords: IEC 62715-6-1:2018, flexible display, mechanical test methods, deformation tests, bending test, rolling test, torsion test, tension test, OLED, LCD, e-paper, display module testing.

Standards Content (Sample)

IEC 62715-6-1 ®
Edition 2.0 2018-04
INTERNATIONAL
STANDARD
colour
inside
Flexible display devices –
Part 6-1: Mechanical test methods – Deformation tests

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.: [phone]
3, rue de Varembé [e-mail]
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: [e-mail].
IEC 62715-6-1 ®
Edition 2.0 2018-04
INTERNATIONAL
STANDARD
colour
inside
Flexible display devices –
Part 6-1: Mechanical test methods – Deformation tests

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.120 ISBN 978-2-8322-5614-5

– 2 – IEC 62715-6-1:2018 © IEC 2018
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Standard atmospheric conditions . 6
5 Specimen preparation . 7
5.1 General . 7
5.2 Sample preparation . 7
6 Mechanical stress test methods . 7
6.1 General . 7
6.2 Cyclic bending test . 8
6.2.1 General . 8
6.2.2 Purpose . 8
6.2.3 Test apparatus . 8
6.2.4 Test procedure . 9
6.2.5 Testing conditions and reporting . 9
6.3 Static bending test . 11
6.3.1 General . 11
6.3.2 Purpose . 11
6.3.3 Test apparatus . 11
6.3.4 Test procedure . 11
6.3.5 Testing conditions and reporting . 12
6.4 Combined bending test . 12
6.4.1 General . 12
6.4.2 Purpose . 12
6.4.3 Test apparatus . 12
6.4.4 Test procedure . 12
6.4.5 Testing conditions and reporting . 13
6.5 Rolling test. 14
6.5.1 General . 14
6.5.2 Purpose . 14
6.5.3 Test apparatus . 14
6.5.4 Test procedure . 15
6.5.5 Testing conditions and reporting . 16
6.6 Static rolling test . 16
6.6.1 General . 16
6.6.2 Purpose . 16
6.6.3 Test apparatus . 16
6.6.4 Test procedure . 17
6.6.5 Testing conditions and reporting . 17
6.7 Torsion test . 18
6.7.1 General . 18
6.7.2 Purpose . 18
6.7.3 Test apparatus . 18
6.7.4 Test procedure . 18
6.7.5 Testing conditions and reporting . 19

6.8 Tension test . 20
6.8.1 General . 20
6.8.2 Purpose . 20
6.8.3 Test apparatus . 20
6.8.4 Test procedure . 20
6.8.5 Testing conditions and reporting . 21
Bibliography . 22

Figure 1 – Apparatus for diverse cyclic bending tests . 10
Figure 2 – Apparatus for static bending test . 11
Figure 3 – Apparatus for combined bending tests consisting of the cyclic bending test
and static bending test . 13
Figure 4 – Apparatus for rolling test . 15
Figure 5 – Apparatus for diverse torsion tests . 19
Figure 6 – Apparatus for tension test . 21

– 4 – IEC 62715-6-1:2018 © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FLEXIBLE DISPLAY DEVICES –
Part 6-1: Mechanical test methods – Deformation tests

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 62715-6-1 has been prepared by IEC technical committee 110:
Electronic display devices.
This second edition cancels and replaces the first edition published in 2014. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) changed the part title to differentiate it from other parts;
b) added new bending testing methods;
c) added detailed testing procedures.

The text of this International Standard is based on the following documents:
FDIS Report on voting
110/951/FDIS 110/974/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.
A list of all the parts in the IEC 62715 series, under the general title Flexible 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.
– 6 – IEC 62715-6-1:2018 © IEC 2018
FLEXIBLE DISPLAY DEVICES –
Part 6-1: Mechanical test methods – Deformation tests

1 Scope
The object of this part of IEC 62715 is to define the standard test methods to evaluate the
mechanical stability of flexible display modules, specifically mechanical stability against
deformation, such as bending, rolling, twisting, and stretching. Display modules include
displays such as LCD, e-paper, and OLED. This document takes into account, wherever
possible, the mechanical test methods outlined under mechanical stress.
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 62341-5:2009, Organic light emitting diode (OLED) displays – Part 5: Environmental
testing methods
3 Terms and definitions
No terms and definitions are listed in this document.
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
4 Standard atmospheric conditions
The standard atmospheric conditions in IEC 62341-5:2009, 5.3, shall apply as follows, unless
otherwise specifically agreed between customer and supplier.
– Temperature: 25 °C ± 3 °C
– Relative humidity: 25 % RH to 85 % RH
– Atmospheric pressure: 86 kPa to 106 kPa
When all the different kinds of tests are carried out, the temperature and humidity condition
shall be reported because the temperature and humidity are critical for the bending and rolling
stability regarding image quality on the panel.
NOTE Preferably, the specimen and apparatus are kept in a controlled environment for at least 24 h prior to and
after assembly, before the start of the mechanical deformation test.

5 Specimen preparation
5.1 General
The specimen shall be the display module since the final evaluation has to be made based on
panel image quality such as luminance, chromaticity, uniformity, line defect, and point defect.
The bending stress may cause the deterioration of image quality on a panel, [1] to [9] .
5.2 Sample preparation
For the measurements both before and after the mechanical deformation test, the display
module being tested shall be aligned on an appropriate support which has to be a flat surface.
In addition, the module for the measurement shall be of the appropriate geometry for
mechanical stress testing. Specify that the test apparatus should be designed to prevent
added strain by stretching test specimens upon folding.
The preferred method of attachment between the display module and the test apparatus is
adhesive transfer tape. The display should be bonded on both sides, and the distance
between the centre of the test specimen and the point of attachment should be specified. If
use scenarios require it, a clamping attachment may be used instead, in which the display is
clamped on one side and allowed to slide on the other. The clamping force should be
sufficient to ensure that the test specimen is firmly anchored to the test apparatus throughout
the entire duration of the test cycle.
If some modules are difficult to clamp due to narrow edge width, the module should be fixed
on a bendable support substrate with a suitable adhesive strip or glue. Neither the adhesive
strip nor the glue should affect the measurement.
NOTE In some cases, the testing specimen can have a short length or has a very narrow edge to clamp for
mechanical stress testing.
Specify that in the event of cross-instrument variability in the form of location (centre or
edge)-response bias, one should investigate bend axis misalignment, bowing or uneven
mounting plates.
For precise optical measurements, it is very important to define the alignment of the
measurement specimen because the flexible display module can be easily deformed by
external force. Measurements of the visual characteristics of a flexible module shall be made
in an aligned flat state. If flexible modules are aligned in a curved state, it is difficult to make a
precise visual evaluation. The measurement module shall be supported or fixed so that it is
flat.
The flatness and size of the specimen shall be determined between the supplier and customer.
6 Mechanical stress test methods
6.1 General
Flexible displays have a diversity of shapes in comparison with any other non-flexible
electronic displays. Therefore, a wide variety of mechanical stress test methods are available,
such as a cyclic bending (folding) or dynamic bending test, a static bending test, a rolling test,
a combined mechanical test and more. The selection of the appropriate test methods shall be
based on the requirement of the application. For each mechanical stress test, the relevant
test method specification shall be stated along with the explanation of the purpose of each
unique test. The allowable critical bending radius of a panel depends on the application of the
flexible display. Therefore, the required critical bending radius will be changed based on the
applications.
___________
Numbers in square brackets refer to the Bibliography.

– 8 – IEC 62715-6-1:2018 © IEC 2018
There are several factors to consider when designing a reliable and repeatable mechanical
folding or deformation test method, as follows:
– Motion profiles controlled by a single hinge (or pivot axis) and which wrap around a
mandrel can stretch samples, and if not precisely actuated or controlled can create a great
deal of variability in the test response.
– Motion profiles controlled by more than one hinge or pivot axis can prevent added
stretching on test specimens, and offer better control of the test response.
– Clamping samples can prevent shear between layers of multi-layer test specimens
containing adhesive, and greatly impact test response.
– Additional considerations, such as attaching too close to the apex of the bend, and fold
axis misalignment or slight distortions in the shape of the mounting plates, can also impact
reliability and repeatability of the test response.
– Samples should be pre-conditioned in a controlled environment for at least 24 h prior to
testing as material properties for adhesives and polymers can be affected by temperature
and water uptake.
6.2 Cyclic bending test
6.2.1 General
This procedure is for conditioning the specimen under mechanical stress by repeated bending.
6.2.2 Purpose
The purpose of this test is to provide a standard procedure for evaluating the robustness of a
flexible display against a cyclic bending stress which might typically happen in application.
The bending properties might cover several typical parameters of the characteristics of a
display panel's image quality. The typical parameters of a display panel's image quality might
cover the luminance, chromaticity, uniformity, line defect, point defect, pixel shrink, and/or
presence or absence of cracks.
6.2.3 Test apparatus
The cyclic bending test equipment includes the clamp to hold a bending test specimen, the
moving part to shuttle, and the control system which regulates the number of cyclic bendings,
the moving distance, and the moving speed while testing. The specimen shall be securely
clamped with a gripping part during the test. Several kinds of cyclic bending test equipment is
available and shown in Figure 1, [4][7][10]. It is not necessary that a certain type of bending
test equipment be preferred but the constant bending radius (r), equal to the radius of the rod,
should be kept during the bending test.
NOTE If the bending radius of the test specimen is kept constant during the bending test, the bending rod can be
removed as it would scratch the surface of the test specimen during the cyclic bending test.
For the cyclic bending test, the following apparatus is considered:
– the specimen experiences a bending stress when the specimen is shuttled back and forth
(Figure 1a)) or while the specimen is folded and unfolded (Figure 1b)),
– when the specimen is repeatedly multi-bent in the inward or outward direction, a cyclic
multi-inward bending equipment (Figure 1c)) or cyclic multi-outward bending equipment
(Figure 1d)) can be used,
– when the specimen is repeatedly multi-bent in a Z-shape, a cyclic multi-bending
equipment can be used,
– when the specimen is repeatedly bent in both the inward and outward direction, a cyclic
inward and outward bending equipment can be used (Figure 1e) and/or f)).

6.2.4 Test procedure
The cyclic bending test shall be performed using a repeated motion to move regularly
between two points or two states (folded state and unfolded state) as follows:
a) Prepare the required number of specimens according to 5.2.
b) Perform the initial performance, visual characteristics, test for the prepared specimens
and record the result.
c) One edge of the specimen is fixed by the clamp, or fixed with an adhesive, and the other
edge is supported properly as stated in 5.2.
d) Bend the specimen properly with defined conditions such as the rotation angle of the
clamp roll and the bending angular velocity.
e) Bring the specimen back to the initial state before the bending.
f) If required, bend the specimen in another direction with defined conditions such as the
rotation angle of the clamp roll and the bending angular velocity.
g) Bring the specimen back to the initial state before the bending with the same angular
velocity and reversed direction.
h) Repeat d) to g) for a defined number of cycles.
i) After the test, the specimen is removed from the apparatus.
j) Repeat the tests with (an)other specimen(s) following c) to j).
k) The stressed performance, visual characteristics of the mechanically stressed specimen(s)
with the required number of testings are measured and the results are recorded. The
initial and stressed performances are compared, and the degree of change due to the
bend is determined.
l) The test and performance measurement for individual specimens are conducted and
recorded in the test report.
6.2.5 Testing conditions and reporting
The testing conditions are specified as follows:
NOTE 1 The numerical values of the test conditions are examples.
a) bending radius
r
...

IEC 62715-6-1 ®
Edition 2.0 2018-04
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Flexible display devices –
Part 6-1: Mechanical stress test methods – Deformation tests

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.: [phone]
3, rue de Varembé [e-mail]
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: [e-mail].
IEC 62715-6-1 ®
Edition 2.0 2018-04
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Flexible display devices –
Part 6-1: Mechanical stress test methods – Deformation tests

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.120 ISBN 978-2-8322-5629-9

– 2 – IEC 62715-6-1:2018 RLV © IEC 2018
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Standard atmospheric conditions . 6
5 Evaluations – Visual evaluation of panel image quality Specimen preparation . 7
5.1 General . 7
5.2 Sample preparation . 7
6 Mechanical stress test methods . 7
6.1 General . 7
6.2 Cyclic bending test . 8
6.2.1 General . 8
6.2.2 Purpose . 8
6.2.3 Test apparatus . 8
6.2.4 Test procedure . 9
6.2.5 Testing conditions and reporting . 9
6.3 Static bending test . 12
6.3.1 General . 12
6.3.2 Purpose . 12
6.3.3 Test apparatus . 12
6.3.4 Test procedure . 12
6.3.5 Testing conditions and reporting . 13
6.4 Combined bending test . 12
6.4.1 General . 13
6.4.2 Purpose . 13
6.4.3 Test apparatus . 13
6.4.4 Test procedure . 14
6.4.5 Testing conditions and reporting . 15
6.5 Rolling test. 15
6.5.1 General . 15
6.5.2 Purpose . 16
6.5.3 Test apparatus . 16
6.5.4 Test procedure . 18
6.5.5 Testing conditions and reporting . 18
6.6 Static rolling test . 18
6.6.1 General . 19
6.6.2 Purpose . 19
6.6.3 Test apparatus . 19
6.6.4 Test procedure . 19
6.6.5 Testing conditions and reporting . 20
6.7 Torsion test . 20
6.7.1 General . 20
6.7.2 Purpose . 20
6.7.3 Test apparatus . 20
6.7.4 Test procedure . 20
6.7.5 Testing conditions and reporting . 22

6.8 Tension test . 20
6.8.1 General . 23
6.8.2 Purpose . 23
6.8.3 Test apparatus . 23
6.8.4 Test procedure . 23
6.8.5 Testing conditions and reporting . 24
Bibliography . 25

Figure 1 – Apparatus for diverse cyclic bending tests . 11
Figure 2 – Apparatus for static bending test . 12
Figure 3 – Apparatus for combined bending tests consisting of the cyclic bending test
and static bending test . 15
Figure 4 – Apparatus for rolling test . 17
Figure 5 – Apparatus for diverse torsion tests . 22
Figure 6 – Apparatus for tension test . 24

– 4 – IEC 62715-6-1:2018 RLV © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FLEXIBLE DISPLAY DEVICES –
Part 6-1: Mechanical stress test methods – Deformation tests

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.
This redline version of the official IEC Standard allows the user to identify the changes
made to the previous edition. A vertical bar appears in the margin wherever a change
has been made. Additions are in green text, deletions are in strikethrough red text.

International Standard IEC 62715-6-1 has been prepared by IEC technical committee 110:
Electronic display devices.
This second edition cancels and replaces the first edition published in 2014. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) changed the part title to differentiate it from other parts;
b) added new bending testing methods;
c) added detailed testing procedures.
The text of this International Standard is based on the following documents:
FDIS Report on voting
110/951/FDIS 110/974/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.
A list of all the parts in the IEC 62715 series, under the general title Flexible 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.
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.
– 6 – IEC 62715-6-1:2018 RLV © IEC 2018
FLEXIBLE DISPLAY DEVICES –
Part 6-1: Mechanical stress test methods – Deformation tests

1 Scope
The object of this part of IEC 62715 is to define the standard test methods to evaluate the
mechanical stability of flexible display modules, specifically mechanical stability against
deformation, such as bending, rolling, twisting, and stretching. Display modules include
displays such as LCD, e-paper, and OLED. This document takes into account, wherever
possible, the mechanical test methods outlined under mechanical stress.
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 62341-5:2009, Organic light emitting diode (OLED) displays – Part 5: Environmental
testing methods
3 Terms and definitions
No terms and definitions are listed in this document.
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
4 Standard atmospheric conditions
The standard atmospheric conditions in IEC 62341-5:2009, 5.3, shall apply as follows, unless
otherwise specifically agreed between customer and supplier. The standard atmospheric
conditions shall be a temperature of 25 °C ± 5 °C, relative humidity between 45 % and 75 %,
and atmospheric pressure between 86 kPa and 106 kPa.
– Temperature: 25 °C ± 3 °C
– Relative humidity: 25 % RH to 85 % RH
– Atmospheric pressure: 86 kPa to 106 kPa
When all the different kinds of tests are carried out, the temperature and humidity condition
shall be commented reported because the temperature is and humidity are critical for the
bending and rolling stability regarding image quality on the panel.
NOTE Preferably, the specimen and apparatus are kept in a controlled environment for at least 24 h prior to and
after assembly, before the start of the mechanical deformation test.

5 Evaluations – Visual evaluation of panel image quality Specimen preparation
5.1 General
The specimen shall be the display module since the final evaluation has to be made based on
panel image quality such as luminance, chromaticity, uniformity, line defect, and point defect.
The bending stress may cause the deterioration of image quality on a panel, [1] to [9] .
5.2 Sample preparation
For the measurements both before and after the mechanical deformation test, the display
module being tested shall be aligned on an appropriate support which has to be a flat surface.
In addition, the module for the measurement shall be of the appropriate geometry for
mechanical stress testing. Specify that the test apparatus should be designed to prevent
added strain by stretching test specimens upon folding.
The preferred method of attachment between the display module and the test apparatus is
adhesive transfer tape. The display should be bonded on both sides, and the distance
between the centre of the test specimen and the point of attachment should be specified. If
use scenarios require it, a clamping attachment may be used instead, in which the display is
clamped on one side and allowed to slide on the other. The clamping force should be
sufficient to ensure that the test specimen is firmly anchored to the test apparatus throughout
the entire duration of the test cycle.
If some modules are difficult to clamp due to narrow edge width, the module should be fixed
on a bendable support substrate with a suitable adhesive strip or glue. Neither the adhesive
strip nor the glue should affect the measurement.
NOTE In some cases, the testing specimen can have a short length or has a very narrow edge to clamp for
mechanical stress testing.
Specify that in the event of cross-instrument variability in the form of location (centre or
edge)-response bias, one should investigate bend axis misalignment, bowing or uneven
mounting plates.
For precise optical measurements, it is very important to define the alignment of the
measurement specimen because the flexible display module can be easily deformed by
external force. Measurements of the visual characteristics of a flexible module shall be made
in an aligned flat state. If flexible modules are aligned in a curved state, it is difficult to make a
precise visual evaluation. The measurement module shall be supported or fixed so that it is
flat.
The flatness and size of the specimen shall be determined between the supplier and customer.
6 Mechanical stress test methods
6.1 General
Flexible displays have a diversity of shapes in comparison with any other non-flexible
electronic displays. Therefore, a wide variety of mechanical stress test methodsare available,
such as a cyclic bending (folding) or dynamic bending test, a static bending test, a rolling test,
a combined mechanical test and more. The selection of the appropriate test methods shall be
based on the requirement of the application. For each mechanical stress test, the relevant
test method specification shall be stated along with the explanation of the purpose of each
unique test. The allowable critical bending radius of a panel depends on the application of the
flexible display. Therefore, the required critical bending radius will be changed case by case
based on the applications.
___________
Numbers in square brackets refer to the Bibliography.

– 8 – IEC 62715-6-1:2018 RLV © IEC 2018
There are several factors to consider when designing a reliable and repeatable mechanical
folding or deformation test method, as follows:
– Motion profiles controlled by a single hinge (or pivot axis) and which wrap around a
mandrel can stretch samples, and if not precisely actuated or controlled can create a great
deal of variability in the test response.
– Motion profiles controlled by more than one hinge or pivot axis can prevent added
stretching on test specimens, and offer better control of the test response.
– Clamping samples can prevent shear between layers of multi-layer test specimens
containing adhesive, and greatly impact test response.
– Additional considerations, such as attaching too close to the apex of the bend, and fold
axis misalignment or slight distortions in the shape of the mounting plates, can also impact
reliability and repeatability of the test response.
– Samples should be pre-conditioned in a controlled environment for at least 24 h prior to
testing as material properties for adhesives and polymers can be affected by temperature
and water uptake.
6.2 Cyclic bending test
6.2.1 General
This procedure is for conditioning the sample specimen under mechanical stress by repeated
bending.
6.2.2 Purpose
The purpose of this test is to provide a standard procedure for evaluating the robustness of a
flexible display against a cyclic bending stress which might typically happen in application.
The bending properties might cover several typical parameters of the characteristics of a
display panel's image quality. The typical parameters of a display panel's image quality might
cover the luminance, chromaticity, uniformity, line defect, point defect, pixel shrink, and /or
presence or absence of cracks.
6.2.3 Test apparatus
The cyclic bending test equipment includes the clamp to hold a bending test sample specimen,
the moving part to shuttle, and the control system which regulates the number of cyclic
bendings, the moving distance, and the moving speed while testing. The specimen shall be
securely clamped with a gripping part during the test. Several kinds of cyclic bending test
equipments are is available and shown in Figure 1, [4][7][10]. It is not necessary that a certain
type of bending test equipment be preferred but the constant bending radius (r), equal to the
radius of the rod, should be kept during the bending test.
NOTE If the bending radius of the test specimen is kept constant during the bending test, the bending rod can be
removed as it would scratch the surface of the test specimen during the cyclic bending test.
For the cyclic bending test, the following apparatus is considered:
– the specimen experiences a bending stress when the specimen is shuttled back and forth
(Figure 1a)) or while the specimen is folded and unfolded (Figure 1b)),
– when the specimen is repeatedly multi-bent in the inward or outward direction, a cyclic
multi-inward bending equipment (Figure 1c)) or cyclic multi-outward bending equipment
(Figure 1d)) can be used,
– when the specimen is repeatedly multi-bent in a Z-shape, a cyclic multi-bending
equipment can be used,
– when the specimen is repeatedly bent in both the inward and outward direction, a cyclic
inward and outward bending equipment can be used (Figure 1e) and/or f)).

6.2.4 Test procedure
The cyclic bending test shall be performed using a repeated motion to move regularly
between two points or two states (folded state and unfolded state) as follows. For each test,
the moving speed, the bending radius and the number of cyclic bending should be mentioned,
because the characteristics of the image quality displayed on the module might depend on
these elements. The direction in which the specimen faces shall be stated, such as face-up or
face-down. For example, the conditions shall be selected as below:
r (bending radius): 20 mm, 10 mm, 5 mm, 3 mm, 2 mm, 1 mm, 0,5 mm, 0,2 mm, 0,1 mm
t ( time for one bend and interval ): 0,5 s, 1 s, 2 s, 3 s, 5 s, 10 s
a) Prepare the required number of specimens according to 5.2.
b) Perform the initial performance, visual characteristics, test for the prepared specimens
and record the result.
c) One edge of the specimen is fixed by the clamp, or fixed with an adhesive, and the other
edge is supported properly as stated in 5.2.
d) Bend the specimen properly with defined conditions such as the rotation angle of the
clamp roll and the bending angular velocity.
e) Bring the specimen back to the initial state before the bending.
f) If required, bend the specimen in another direction with defined conditions such as the
rotation angle of the clamp roll and the bending angular velocity.
g) Bring the specimen back to the initial state before the bending with the same angular
velocity and reversed direction.
h) Repeat d) to g) for a defined number of cycles.
i) After the test, the specimen is removed from the apparatus.
j) Repeat the tests with (an)other specimen(s) following c) to j).
k) The stressed performance, visual characteristics of the mechanically stressed specimen(s)
with the required number of testings are measured and the results are recorded. The
initial and stressed performances are compared, and the degree of change due to the
bend is determined.
l) The test and performance measurement for individual specimens are conducted and
recorded in the test report.
6.2.5 Testing conditions and reporting
The testing conditions are specified as follows:
NOTE 1 The numerical values of the test conditions are examples.
a) bending radius
r (bending radius): 20 mm, 10 mm, 5 mm, 3 mm, 2 mm, 1 mm, 0,5 mm, 0,2 mm
b) bending angle and angular velocity, procedure for one cycle
t (time for one bend and interval ): 0,5 s, 1 s, 2 s, 3 s, 5 s, 10 s
c) load
d) number of repeating cycles
e) criteria for acceptance
f) number of specimens
g) the bending inner surface is the top surface (face up) or the back side surface (face down)
h) way of holding specimens and detailed method of holding, such as pressure
i) surface condition (such as treatment) of both specimen and apparatus
j) testing of environmental conditions, such as temperature and humidity.

– 10 – IEC 62715-6-1:2018 RLV © IEC 2018
NOTE 2 The criteria for acceptance include the visual performance and specimen geometry both before and after
the stressing.
All conditions shall be reported if the test uses conditions other than those mentioned above.

Rod Panel Clamp
IEC  0224/14
a)
Panel
Clamp
Rod
Frame
IEC  0225/14
b)
Bending angle
Panel
Clamp
Rod
Frame
Bending angle
Panel
Clamp
Rod Panel
Clamp
r
r
Frame
IEC
IEC
a) Cyclic bending (sliding) equipment b) Cyclic bending equipment
Panel
Panel
Panel Panel
IEC
IEC
c) Cyclic multi-inward bending equipment d) Cyclic multi-outward bending equipment

Panel
Panel
Panel
Panel
IEC IEC
e) Cyclic multi-bending equipment f) Cyclic inward and outward bending equipment
Figure 1 – Apparatus for diverse cyclic bending tests

– 12 – IEC 62715-6-1:2018 RLV © IEC 2018
6.3 Static bending test
6.3.1 General
This test is especially applicable for evaluating the static bending properties of a flexible
display device by measuring its performance after it remains bent for a certain period of time.
Each specimen is bent at a fixed bending radius for any length of time.
6.3.2 Purpose
This test is to provide a standard procedure for evaluating the static bending properties of a
flexible display device under constant stress for a certain period of time. Each specimen is
bent at a fixed bending radius for a controlled length of time.
6.3.3 Test apparatus
The body of the display panel shall firmly adhere to the surface of the test equipment during
the test, where the test equipment should have a round shape with a certain radius as in
Figure 2. The specimen shall be bent at a fixed bending radius for a period of time.
If the bending radius of the test specimen is kept constant during the bending test, the
bending rod can be removed as it may scratch the surface of the test specimen during the
static bending test. During the test, the flexible printed circuit (FPC) and the driver should be
carefully handled in order not to cause so that they are not subject to bending damage on
them. The chip-on-film (COF) method is preferable in order to avoid the occurrence of
bending damage on the driver’s integrated circuit (IC) during the bending test.

IEC  0226/14
IEC
Figure 2 – Apparatus for static bending test
6.3.4 Test procedure
The static time bending test shall be carried out with a fixed bending radius for a certain
period of time, as follows. For each test, the bending radius and the period of time shall be
mentioned because the static bending properties of the characteristics of the display panel
image quality might depend on the bending radius and the period of time.
a) Prepare the required number of specimens according to 5.2.
b) Perform the initial performance, visual characteristics, test for the prepared specimens
and record the result.
c) One edge of the specimen is fixed by the clamp and the other edge is supported properly.
d) Bend the specimen properly with defined conditions such as the rotation angle of the
clamp roll and the bending angular velocity.
e) Keep the specimen bent for certain period of time.
f) Bring the specimen back to the initial state before the bending.
g) Repeat d) to f) for a defined number of tests.

h) After the bending, the specimen is removed from the apparatus.
i) Repeat the tests with (an)other specimen(s) following c) to g).
j) The stressed performance and visual characteristics of mechanically stressed specimen(s)
with the required number of testings are measured, and the results are recorded. The
initial and stressed performances are compared, and the degree of change due to bending
is determined.
k) The test and performance measurement for individual specimens are conducted and
recorded in the test report.
6.3.5 Testing conditions and reporting
The testing conditions are specified as follows:
NOTE 1 The numerical values of the test conditions are examples.
a) bending radius
r (bending radius): 20 mm, 10 mm, 5 mm, 3 mm, 2 mm, 1 mm, 0,5 mm, 0,2 mm
b) bending angle
c) holding duration
d) load
e) criteria for acceptance
f) number of specimens
g) the bending inner surface is the top surface (face-up) or backside surface (face-down)
h) way of holding specimens and detailed method of holding, such as pressure
i) surface condition (such as treatment) of both specimen and apparatus
j) testing of environmental conditions, such as temperature and humidity
NOTE 2 The criteria for acceptance include visual performance and specimen geometry both before and after the
stressing.
All conditions shall be reported if the test uses conditions other than those mentioned above.
6.4 Combined bending test
6.4.1 General
This test is especially applicable for evaluating two kinds of combined bending properties
(cyclic bending properties and static bending properties (see Figure 3)) of the flexible display
device, after the flexible display remains in the curved shape for a certain period of time and
goes through the cyclic bending condition for a certain period of time in real usage use
environment.
6.4.2 Purpose
The objective of this test is to provide a standard procedure for evaluating the combined
bending properties of cyclic bending and duration time bending. This test aims to take the real
product usage use environment into consideration, where the real product keeps the panel in
a curved, folded, or rolled shape for a long time when it is used or before it is rolled out.
6.4.3 Test apparatus
The combined bending test utilizes the same apparatus as the cyclic bending test as shown in
Figure 3. The instrument controller shall be capable of stopping the mechanism while the
sample specimen is in a bent state during each iteration of the cycle.

– 14 – IEC 62715-6-1:2018 RLV © IEC 2018
6.4.4 Test procedure
The cyclic bending test procedure is modified to include a pause ‘hold’ of adjustable duration
between each iteration of the cycle where the specimen remains in a fully bent state [4] as
follows. The entire test sequence and all of the test conditions of the cyclic bending test part
and the static bending test part shall be reported to ensure reproducibility.
a) Prepare the required number of specimens according to 5.2.
b) Perform the initial performance, visual characteristics, test for the prepared specimens
and record the result.
c) One edge of the specimen is fixed by the clamp and the other edge is supported properly.
d) Bend the specimen properly with defined conditions such as the rotation angle of the
clamp roll and the bending angular velocity.
e) Bring the specimen back to the initial state before the bending.
f) After performing a certain number of times the bending test in d) and e), bring the
specimen in a fully bent state, then hold.
g) After certain a period of time on hold, bring the specimen back to the initial state.
h) If required, bend the specimen in another direction with defined conditions such as the
rotation angle of the clamp roll and the bending angular velocity.
NOTE If required, the specimen and apparatus are set in a proper setting, such as rotation of the rod, etc.
i) The bent module is returned to the initial state before the bending with the same angular
velocity and reversed direction.
j) After performing a certain number of times the bending test in h) and i), bring the
specimen in the fully bent state, and then hold.
k) After the test, bring the specimen back to the initial state.
l) Repeat d) to k) for a defined number of cycles.
m) Bring the specimen back to the initial state.
n) Repeat the test with (an)other specimen(s) following c) to m).
o) The stressed performance and visual characteristics of the mechanically stressed
specimen(s) with the required number of testings are measured, and the results are
recorded. The initial and stressed performances are compared, and the degree of change
due to the bend is determined.
p) The test and performance measurement for individual specimens are conducted and
recorded in the test report.
Clamp
Rod Panel
(Cyclic bending) (Static bending)
IEC
a) Combined bending test A
Panel
Clamp
Rod
Frame
(Cyclic bending) (Static bending)
IEC
b) Combined bending test B
Figure 3 – Apparatus for combined bending tests consisting
of the cyclic bending test and static bending test
6.4.5 Testing conditions and reporting
The testing conditions are specified as follows:
NOTE 1 The numerical values of the test conditions are examples.
a) bending radius
r (bending radius): 20 mm, 10 mm, 5 mm, 3 mm, 2 mm, 1 mm, 0,5 mm, 0,2 mm
b) bending angle and angular velocity, procedure for one cycle
t (time for one bend and interval ): 0,5 s, 1 s, 2 s, 3 s, 5 s, 10 s
c) duration of ‘hold’ state
d) load
e) number of repeating cycles
f) criteria for acceptance
g) number of specimens
h) the bending inner surface is the top surface (face up) or backside surface (face down)
i) way of holding specimens and detailed method of holding, such as pressure
j) surface condition (such as treatment) of both specimen and apparatus
k) testing of environmental conditions, such as temperature and humidity
NOTE 2 The criteria for acceptance include the visual performance and specimen geometry both before and after
the stressing.
All conditions shall be reported if the test uses conditions other than those mentioned above.
6.5 Rolling test
6.5.1 General
This test is especially applicable for evaluating the rolling properties of a flexible display
module after a flexible display is rolled out, rolled in, or remains in the shape of a roll.

– 16 – IEC 62715-6-1:2018 RLV © IEC 2018
6.5.2 Purpose
The objective of this test is to provide a standard procedure for evaluating the robustness of
the rolling properties of the flexible display panel.
6.5.3 Test apparatus
The specimen shall be firmly clamped with a gripping part on the roller side and on the
stationary side. The roller shall be reciprocated moved forward and backward alternately at a
fixed distance, speed, and rolling number as in Figure 4. The roller side has a slot where the
edge of the specimen is inserted and clamped. The roller repeatedly shuttles along the roller
shaft and the specimen does not touch the plate of the equipment during the rolling test as
shown in Figure 4.
During the test, the FPC and the driver shall should be carefully handled in order not to cause
so that they are not subjected to twist damage on them. The COF method is preferable in
order to avoid prevent the occurrence of twist damage on the driver’s IC during the bending
test.
Clamp (gripping part)
Sample
FPC
Roller
Roller shaft
Clamp (gripping part)
Sample
Plate
IEC  0229/14
Clamp (gripping part)
Sample
FPC
Roller
Roller shaft
Clamp (gripping part)
Sample
Plate
Type A
Clamp (gripping part)
Specimen
Roller FPC
Shaft
Plate
Type B
IEC
Figure 4 – Apparatus for rolling test

– 18 – IEC 62715-6-1:2018 RLV © IEC 2018
6.5.4 Test procedure
A fixed area of the specimen shall be cyclically wounded and unwounded around the roller.
The winding rate and the cycle count will be controlled. The test conditions and settings shall
be reported to ensure reproducibility.
The rolling test shall be performed as follows:
a) Prepare the required number of specimens according to 5.2.
b) Perform the initial performance, visual characteristics, and test for the prepared
specimens and record result.
c) Each specimen size is measured and recorded.
d) One edge of the specimen is fixed on the roll as shown in Figure 4 and the other edge
clamp is supported with an individually defined load. Align the specimen with the top
surface on the inner or the outer side of the roller.
e) Roll the specimen with defined conditions such as rolling radius, rolling distance, rolling
angular velocity and load.
f) Bring the specimen back to the initial state before the rolling, with the same angular
velocity and reversed rotation direction.
g) Repeat d) to e) for a defined number of cycles. It is optional to test the other surface side
at the same conditions, this being done by agreement between supplier and customer. In
this case, follow d) to g) with the reversed surface side.
h) After the test, remove the specimen from the apparatus.
i) Repeat the test with (an)other specimen(s) following c) to h).
j) The stressed performance, electrical and optical characteristics of the mechanically
stressed module(s) with the required number of testings are measured, and the results are
recorded. The initial and stressed performances are compared, and the degree of change
due to the rolling test is determined.
k) The test and performance measurement for individual specimens are conducted and
recorded in the test report.
6.5.5 Testing conditions and reporting
The testing conditions are specified as follows:
a) roll radius
b) angular velocity, procedure for one cycle
c) holding duration
d) load
e) number of repeating cycles
f) criteria for acceptance
g) number of specimens
h) rolling inner surface (top surface or back surface)
i) way of holding specimens and detailed method of holding, such as pressure
j) surface condition (such as treatment) of both specimen and apparatus
k) testing of environmental conditions, such as temperature and humidity.
NOTE The criteria for acceptance include the visual performance and specimen geometry both before and after
the stressing.
All conditions shall be reported if the test uses conditions other than those mentioned above.

6.6 Static rolling test
6.6.1 General
This test is especially applicable for evaluating the static rolling properties of a flexible display
module after a flexible display is rolled out, rolled in, or remains in the shape of a roll.
6.6.2 Purpose
The objective of this test is to provide a standard procedure for evaluating the robustness of
the static rolling properties of the flexible display panel.
6.6.3 Test apparatus
The specimen shall be firmly clamped with a gripping part on the roller side and on the
stationary side. The roller shall be moved forward and backward alternately at a fixed
distance, speed, and rolling number as in Figure 4. The roller side has a slot where the edge
of the specimen is inserted and clamped. The roller repeatedly shuttles along the roller shaft
and the specimen does not touch the plate of the equipment during the rolling test as shown
in Figure 4.
During the test, the FPC and the driver should be carefully handled so that they are not
subjected to twist damage. The COF method is preferable in order to prevent the occurrence
of twist damage on the driver IC during the bending test.
6.6.4 Test procedure
The rolling test shall be performed as follows:
a) Prepare the required number of specimens according to 5.2.
b) Perform the initial performance, visual characteristics, test for the prepared specimens
and record the result.
c) Each specimen size is measured and recorded.
d) One edge of the specimen is fixed on the roll as shown in Figure 4 and the other edge
clamp is supported with an individually defined load. Align the specimen with the top
surface on the inne
...