IEC 62899-202-5:2018

IEC 62899-202-5 ®
Edition 1.0 2018-09
INTERNATIONAL
STANDARD
colour
inside
Printed electronics –
Part 202-5: Materials – Conductive ink – Mechanical bending test of a printed
conductive layer on an insulating substrate

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IEC 62899-202-5 ®
Edition 1.0 2018-09
INTERNATIONAL
STANDARD
colour
inside
Printed electronics –
Part 202-5: Materials – Conductive ink – Mechanical bending test of a printed

conductive layer on an insulating substrate

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.180; 87.080 ISBN 978-2-8322-6072-2

– 2 – IEC 62899-202-5:2018 © IEC 2018
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Standard environmental conditions . 7
5 Test sample . 7
5.1 General . 7
5.2 Size of test sample . 8
6 Testing method and test apparatus . 8
6.1 General . 8
6.2 Test apparatus . 8
6.3 Test procedure . 9
6.4 Measurement . 10
7 Data analysis . 11
7.1 Reporting the electrical properties . 11
7.2 Report of the results . 11
Annex A (normative) Stress state in bending deformation – Bending strain calculation . 12
Annex B (informative) Damage area and electrical resistance change after sliding
plate test. 13
B.1 Damage area . 13
B.2 Comparison of bending test methods . 13
Bibliography . 15

Figure 1 – Schematic diagram of mechanical test of printed film . 8
Figure 2 – Apparatus for mechanical test of printed film . 9
Figure A.1 – Bending strain and curvature relation in bent printed film . 12
Figure A.2 – Schematic of outer bending and inner bending . 12
Figure B.1 – Images of metal film after sliding test . 13
Figure B.2 – Electrical resistance changes of sliding plate test and simple bending test . 14

Table 1 – List of the size of the specimen . 8
Table 2 – Combination of the effective sample length and the linear motion length . 10
Table 3 – Resistance range of the test piece and the applied current . 10

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PRINTED ELECTRONICS –
Part 202-5: Materials – Conductive ink – Mechanical bending test
of a printed conductive layer on an insulating substrate

FOREWORD
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International Standard IEC 62899-202-5 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
119/227/FDIS 119/235/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 62899-202-5:2018 © IEC 2018
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.

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INTRODUCTION
The printing process is a highly promising technology for the fabrication of flexible devices. In
particular, a printed conductive layer on an insulating substrate will be widely employed as an
electrode or as an interconnect for flexible devices. It will be dealt with and commercialized as
a type of composite material in which the conductive layer is formed on the substrate as a
conductor.
For a conductive film, the electrical property under mechanical deformation is very important
because it is highly sensitive to mechanical stress and degrades well before the mechanical
fracture. Therefore, a method for evaluating the conductivity of film materials provided by
suppliers, sometimes including an in situ measurement system, is required in the industry as
these are the basic materials which will be used in printed devices. Although some bending
tests already exist, it is necessary to consider the unique characteristics of the printed films
that are fabricated on a polymer substrate, which is weak under high temperature. These films
are operated under severe mechanical deformations, unlike the conventional
Si- or glass-based conductive films.
In this document, a mechanical bending test is described to evaluate the electrical property of
a printed conductive layer on a substrate under repeated mechanical deformations. This
sliding plate test method can be available for practical application in the industry by enabling
the long-term reliability testing of printed film.

– 6 – IEC 62899-202-5:2018 © IEC 2018
PRINTED ELECTRONICS –
Part 202-5: Materials – Conductive ink – Mechanical bending test
of a printed conductive layer on an insulating substrate

1 Scope
This International Standard specifies a mechanical bending test for evaluating the electrical
properties of a printed conductive layer on an insulating su
...