IEC 62899-502-1:2017

IEC 62899-502-1 ®
Edition 1.0 2017-03
INTERNATIONAL
STANDARD
colour
inside
Printed electronics –
Part 502-1: Quality assessment – Organic light emitting diode (OLED) elements –
Mechanical stress testing of OLED elements formed on flexible substrates

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IEC 62899-502-1 ®
Edition 1.0 2017-03
INTERNATIONAL
STANDARD
colour
inside
Printed electronics –
Part 502-1: Quality assessment – Organic light emitting diode (OLED) elements –

Mechanical stress testing of OLED elements formed on flexible substrates

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.035.01; 31.260 ISBN 978-2-8322-4078-6

– 2 – IEC 62899-502-1:2017 © IEC 2017
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
3.1 General terms . 8
3.2 Terms related to optical and electrical properties . 8
3.3 Terms related to mechanical stress test . 9
4 Standard atmospheric condition for measurements and tests . 9
5 Evaluation methods of optical and electrical properties . 9
5.1 General . 9
5.2 Sample preparation of OLED element(s) for optical and electrical
measurements . 9
5.3 IVL characteristics . 10
5.4 Luminous flux . 10
5.5 Luminance uniformity . 10
6 Mechanical stress test methods . 10
6.1 General . 10
6.2 Bending test . 10
6.2.1 General . 10
6.2.2 Testing apparatus . 10
6.2.3 Testing procedure . 10
6.2.4 Evaluation . 11
6.2.5 Testing conditions . 11
6.3 Rolling test. 12
6.3.1 General . 12
6.3.2 Testing apparatus . 12
6.3.3 Testing procedure . 12
6.3.4 Evaluation . 13
6.3.5 Testing conditions . 13
6.4 Torsion test . 14
6.4.1 General . 14
6.4.2 Testing apparatus . 14
6.4.3 Testing procedure . 14
6.4.4 Evaluation . 15
6.4.5 Testing conditions . 15
6.5 Tension test . 16
6.5.1 General . 16
6.5.2 Testing apparatus . 16
6.5.3 Testing procedure . 16
6.5.4 Evaluation . 16
6.5.5 Testing conditions . 16
7 Failure criteria . 17
Annex A (normative) Measurement methods of IVL characteristics . 18
A.1 General . 18
A.2 Measurement method . 18

A.2.1 General . 18
A.2.2 Measurement apparatus . 18
A.2.3 Measurement procedure . 18
A.2.4 Acceptance . 18
A.2.5 Items for relevant specification . 18
Annex B (normative) Measurement methods of luminous flux . 20
B.1 General . 20
B.2 Measurement method . 20
B.2.1 General . 20
B.2.2 Measurement apparatus . 20
B.2.3 Measurement procedure . 21
B.2.4 Acceptance . 22
B.2.5 Terms for additional definition . 22

Figure 1 – Apparatus for bending test . 12
Figure 2 – Apparatus for rolling test . 13
Figure 3 – Apparatus for torsion test . 15
Figure 4 – Example of sample alignment for torsion testing . 15
Figure 5 – Apparatus for tension test . 17
Figure A.1 – Layout of luminous measurement system . 19
Figure B.1 – Example of measurement apparatus for luminous flux using an integral
sphere . 21

– 4 – IEC 62899-502-1:2017 © IEC 2017
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PRINTED ELECTRONICS –
Part 502-1: Quality assessment – Organic light emitting diode (OLED)
elements – Mechanical stress testing of OLED elements
formed on flexible substrates
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62899-502-1 has been prepared by IEC technical committee 119:
Printed electronics.
The text of this International Standard is based on the following documents:
FDIS Report on voting
119/138/FDIS 119/148/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 parts in the IEC 62899 series, published under the general title Printed electronics,
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 62899-502-1:2017 © IEC 2017
INTRODUCTION
In contrast to existing lighting tiles formed on heavy and rigid substrates, printed flexible
organic light emitting diodes (OLED) are expected to be thin and light-weight, and to be used
as flexible lighting elements for emerging applications such as newly designed lighting for,
architecture, automobile, aircraft and so on.
It is highly beneficial to standardize quality assessment methods of printed flexible OLED
elements for both manufacturers and users at an early stage of the growing market for the
devices. In addition, the standardization helps to settle the contents for the technological
development. The standardization of testing conditions for mechanical stress is very much
expected to evaluate the printed flexible OLED elements and to accelerate the expansion of
the printed electronics (PE) market opportunities for flexible device applications.
This document defines testing conditions for mechanical stress, in the form of curving, rolling,
and/or folding on printed flexible OLED elements. The mechanical stresses for the test are
applied as specific forms under defined conditions, which depend on the specific applications
including rigidly fixed lighting for the printed flexible OLED elements. This document also
defines coexisting environmental conditions such as temperature, humidity and air pressure.
This document includes evaluation methods of optical and electrical properties for the
performance change induced by the stress test on the printed flexible OLED elements.

PRINTED ELECTRONICS –
Part 502-1: Quality assessment – Organic light emitting diode (OLED)
elements – Mechanical stress testing of OLED elements
formed on flexible substrates
1 Scope
This part of IEC 62899 specifies the quality assessment methods, especially the mechanical
stress test methods, for reliability assessment.
This document is applicable to flexible OLED elements formed on flexible substrates by
printed electronics technology excluding those OLED products, which are intended to be used
for lighting purposes.
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 62715-6-1, Flexible display devices – Part 6-1: Mechanical stress test methods
IEC 62341-5:2009, Organic light emitting diode (OLED) displays – Part 5: Environmental
testing methods
IEC 62341-6-1, Organic light emitting diode (OLED) displays – Part 6-1: Measuring methods
of optical and electro-optical parameters
IEC 62595-2-1:2016, Display lighting unit – Part 2-1: Electro-optical measurement methods of
LED backlight unit
IEC 62922, Organic light emitting diode (OLED) panels for general lighting – Performance
requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 62922 and
IEC 62715-6-1, and the following 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.

– 8 – IEC 62899-502-1:2017 © IEC 2017
3.1 General terms
3.1.1
OLED element
light emitting element formed with at least one light emitting organic semiconductor film
layered with an anode electrode and a cathode electrode and classified into two categories,
lighting and display
Note 1 to entry: For display usage, printed OLED elements are applicable for back-lighting, etc.
3.1.2
printed OLED element
light emitting element formed with at least one printed layer in OLED structure, where the
printed layer is selected from an anode electrode, hole injection layer, hole transport layer,
light emitting layer, electron transport layer, electron injection layer, charge generation layer,
cathode electrode, passivation layer, smoothing layer, etc.
3.1.3
flexible substrate
substrate with flexibility on which a flexible light emitting element is attached such as plastic
film, thin glass, metal foil, paper, or cloth
3.1.4
flexibility
mechanically bendable property upon stress, which is restored to its original state after
removal of the stress and which is deformed from its initial state
3.1.5
flexible OLED element
mechanically bendable element in at least one step among substrate handling, manufacturing
storage, use, operation, shipping and relocation
3.2 Terms related to optical and electrical properties
3.2.1
IVL characteristics
correlation between electric power, product of current (I) and voltage (V), applied to the OLED
element with a defined electrical condition and light flux (L) emitted from the OLED element
3.2.2
luminous flux
total flux from the light source
Note 1 to entry: This is expressed as lumen (lm).
3.2.3
maintenance of luminous flux
changes in the luminous flux of the OLED element for driving and/or storage to the initial
luminous flux
3.2.4
luminance uniformity
qualifying value of the distribution of luminance on OLED element(s) luminance uniformity or
non-uniformity of the OLED element is evaluated as defined in IEC 62595-2-1:2016

3.3 Terms related to mechanical stress test
3.3.1
bending test
deformation caused by external stress in the perpendicular direction on the flat plane of the
OLED element
3.3.2
rolling test
deformation caused by external stress which forms a rolledl shape from a flat shape, on at
least one area of the front-side surface facing the back-side surface of the OLED element
3.3.3
torsion test
deformation which twists the OLED element plane, pulling each edge in different directions
3.3.4
tension test
pulling force applied to at least one direction of the OLED element along the plane
4 Standard atmospheric condition for measurements and tests
Standard atmospheric conditions defined in IEC 62341-5:2009, 5.3, shall apply.
5 Evaluation methods of optical and electrical properties
5.1 General
Both before and after mechanical stress testing in Clause 6, the following measurements on
the electrical and optical characteristics of OLED element(s) shall be performed in the
standard environmental conditions defined in Clause 4. Measurement samples shall be
prepared according to 5.2 before the measurement defined in 5.3 and 5.4. IEC 62922 and
IEC 62341-6-1 apply for measuring the optical and electro-optical parameters.
a) IVL characteristics (5.3)
b) luminous flux (5.4)
Measurements of maintenance of luminous flux are important parameters for OLED elements
however
...