IEC 62899-502-2:2019

IEC 62899-502-2 ®
Edition 1.0 2019-07
INTERNATIONAL
STANDARD
colour
inside
Printed electronics –
Part 502-2: Quality assessment – Organic light emitting diode (OLED) elements –
Combined mechanical and environmental stress test methods for flexible OLED
elements
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IEC 62899-502-2 ®
Edition 1.0 2019-07
INTERNATIONAL
STANDARD
colour
inside
Printed electronics –
Part 502-2: Quality assessment – Organic light emitting diode (OLED) elements –

Combined mechanical and environmental stress test methods for flexible OLED

elements
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.035.01; 31.260 ISBN 978-2-8322-7220-6

– 2 – IEC 62899-502-2:2019  IEC 2019
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 General . 8
4.1 Overview. 8
4.2 Structure of measuring equipment . 8
4.3 Standard conditions . 8
4.4 Standard atmospheric conditions for referee measurements and tests . 8
4.5 Standard atmospheric conditions for measurements and tests . 9
4.6 Recovery conditions . 9
4.7 Operating conditions . 9
4.8 Flexible OLED element test configuration. 9
5 Measurements and analysis . 9
5.1 General . 9
5.2 Sample preparation of OLED element(s) for optical and electrical
measurements . 10
5.3 Visual inspection . 10
5.4 IVL characteristics . 10
5.5 Luminous flux . 10
5.6 Mechanical status . 10
6 Combined mechanical and environmental stress test . 10
6.1 Mechanical stress test (deformation) . 10
6.2 Cyclic bending test . 11
6.2.1 General . 11
6.2.2 Purpose . 11
6.2.3 Test apparatus . 11
6.2.4 Testing conditions . 11
6.2.5 Test procedure . 11
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 Testing conditions . 13
6.3.5 Test procedure . 13
6.4 Dynamic and static rolling test . 14
6.4.1 General . 14
6.4.2 Purpose . 14
6.4.3 Test apparatus . 14
6.4.4 Testing conditions . 15
6.4.5 Test procedure . 16
6.5 Environmental testing methods . 16
6.5.1 General . 16
6.5.2 Environmental test at certain temperatures . 16
7 Reports and results . 18

Annex A (normative) IVL measurement methods . 19
A.1 General . 19
A.2 Measurement method . 19
A.2.1 General . 19
A.2.2 Measurement apparatus . 19
A.2.3 Measurement procedure . 19
A.2.4 Acceptance . 19
A.2.5 Items for the relevant specification . 19
Annex B (normative) Luminous flux measurement methods . 21
B.1 General . 21
B.2 Measurement method . 21
B.2.1 General . 21
B.2.2 Measurement apparatus . 21
B.2.3 Measurement procedure . 22
B.2.4 Acceptance . 23
B.2.5 Terms for additional definition . 23
Bibliography . 24

Figure 1 – Apparatus for cyclic bending test . 12
Figure 2 – Apparatus for static bending test . 13
Figure 3 – Example of apparatus for rolling test . 15
Figure A.1 – Layout of luminous measurement system . 20
Figure B.1 – Example of measurement apparatus for luminous flux using an integral
sphere . 22

Table 1 – Standard conditions for referee measurements and tests . 8
Table 2 – Examples of the test conditions . 17

– 4 – IEC 62899-502-2:2019  IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PRINTED ELECTRONICS –
Part 502-2: Quality assessment –
Organic light emitting diode (OLED) elements –
Combined mechanical and environmental stress
test methods for flexible OLED elements

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
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agreement between the two organizations.
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 62899-502-2 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
119/271/FDIS 119/278/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 62899-502-2:2019  IEC 2019
INTRODUCTION
Electronic devices made by printing processes have very unique characteristics, as they are
flexible, with foldable, rollable and/or conformable capabilities, compared to the electronic
devices made through conventional non-printing processes that are mostly rigid. Given these
characteristics, these devices can show different phenomena from those by non-printing
processes under some conditions. In order to evaluate these phenomena, several unique
evaluation methods are used for these devices made by the printing process. This document
will provide one of them.
PRINTED ELECTRONICS –
Part 502-2: Quality assessment –
Organic light emitting diode (OLED) elements –
Combined mechanical and environmental stress
test methods for flexible OLED elements

1 Scope
This part of IEC 62899 specifies the combined mechanical and environmental stress test
methods for flexible OLED (organic light emitting diode) elements fabricated using the printing
method. Mechanical stress tests include the static and cycling vending test, and the dynamic
and static rolling test.
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 60068-2-2, Environmental testing – Part 2-2: Tests – Test B: Dry heat
IEC 62341-6-1, Organic light emitting diode (OLED) displays – Part 6-1: Measuring methods
of optical and electro-optical parameters
IEC 62341-6-2, Organic light emitting diode (OLED) displays – Part 6-2: Measuring methods
of visual quality and ambient performance
IEC 62341-6-3, Organic light emitting diode (OLED) displays – Part 6-3: Measuring methods
of image quality
IEC 62715-5-1, Flexible display devices – Part 5-1: Measuring methods of optical
performance
IEC 62715-5-3, Flexible display devices – Part 5-3: Visual assessment of image quality and
defects
IEC 62715-6-1, Flexible display devices – Part 6-1: Mechanical test methods – Deformation
tests
IEC 62899-502-1, Printed electronics – Part 502-1: Quality assessment – Organic light
emitting diode (OLED) elements – Mechanical stress testing of OLED elements formed on
flexible substrates
IEC 62922, Organic light emitting diode (OLED) panels for general lighting – Performance
requirements
– 8 – IEC 62899-502-2:2019  IEC 2019
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 62899-502-1 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
4 General
4.1 Overview
The flexible OLED elements can show some level of property variation applied by mechanical
stress in certain environmental conditions such as a hot or cool atmosphere. In order to
evaluate adequately these variations, environmental test conditions combined with a
mechanical test are introduced.
4.2 Structure of measuring equipment
The system diagrams and/or operating conditions of the measuring equipment shall comply
with the structure specification of each item.
4.3 Standard conditions
The standard testing conditions shall be as follows:
– temperature: 25 °C
– atmosphere: 101,3 kPa
If the parameters to be measured depend on temperature and/or pressure, and their
dependence on temperature and pressure is known, the parameter values can be measured
under the conditions specified in 4.5 and corrected by calculation to the standard reference
atmosphere above.
4.4 Standard atmospheric conditions for referee measurements and tests
If the parameters to be measured depend on temperature, pressure and humidity and their
dependence on temperature, pressure and humidity is unknown, the atmospheres to be
specified shall be selected from the following values, as shown in Table 1. The selected
values shall be noted in the relevant specifications.
Table 1 – Standard conditions for referee measurements and tests
a b b
Temperature Relative humidity Air pressure
°C % RH kPa
20 ± 1 (close)/ ± 2 (wide) 63 to 67 (close), 60 to 70 (wide) 86 to 106
25 ± 1 (close)/ ± 2 (wide) 48 to 52 (close), 45 to 55 (wide) 86 to 106
30 ± 1 (close)/ ± 2 (wide)
45 to 75 86 to 106
35 ± 1 (close)2/ ± 2 (wide)
a
The close tolerances may be used for the referee measurements. The wider tolerances
may be used only when allowed by the relevant specification.
b
Inclusive values.
4.5 Standard atmospheric conditions for measurements and tests
Unless otherwise specified, all tests and measurements shall be carried out under standard
atmospheric conditions:
– temperature: (25 ± 5) °C
– relative humidity: (60 ± 15) %
– atmospheric pressure: (96 ± 10) kPa
4.6 Recovery conditions
The recovery conditions specified in IEC 60068-1:2013, 4.4 shall be applied.
The OLED element shall be subjected to the recovery procedure in the chamber or otherwise
as appropriate.
The OLED element shall then remain under standard atmospheric conditions for recovery for
a period adequate for the attainment of temperature stability, for a minimum of 1 h.
If required by the relevant specification, the element shall be switched on or loaded and
measured continuously during the recovery period.
If the standard conditions given above are not appropriate for the device to be tested, the
relevant specification may call for other recovery conditions.
4.7 Operating conditions
Apply the proper driving current and voltage to the OLED element to provide luminosity at
normal intended operation.
4.8 Flexible OLED element test configuration
Unless otherwise specified, the OLED element shall be tested in a state that is ready for
normal operation without any protective elements added, nor voltage applied.
5 Measurements and analysis
5.1 General
Both before and after the combined stress testing in Clause 6, the following measurements on
the electrical, optical and mechanical 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 measurements defined in 5.3 and 5.4. Both IEC 62922
and IEC 62341-6-1 are applied to measure the optical and electro-optical parameters.
a) Visual inspection (see 5.3): Visual inspection shall be performed according to IEC 62715-
5-3.
b) IVL (intensity of electric current, voltage, luminance) characteristics (see 5.4).
c) Luminous flux (see 5.5): Optical performance measurement shall refer to IEC 62715-5-1.
d) Mechanical status (5.6).
e) Image quality: Image quality measurement shall refer to IEC 62341-6-2 and IEC 62341-6-3.
Depending on the purpose of the test, only one, some, or all of the methods shall be used.
The measuring frequency and evaluation criteria shall be specified in the detailed
specifications.
– 10 – IEC 62899-502-2:2019  IEC 2019
NOTE Measurements of luminous intensity distribution and maintenance of luminous flux are important
parameters for OLED elements, however these measurements, in particular for maintenance of luminous flux, can
cause degradation of OLED elements which will disturb evaluation of the mechanical stress testing of OLED
elements. Since these measurements would be applicable for an evaluation as a final product, but not practically
suitable for an evaluation as an element for this case, they are eliminated for evaluating the OLED elements both
before and
...