IEC 62899-202-4:2021

Printed electronics - Part 202-4: Materials - Conductive ink - Measurement methods for properties of stretchable printed layers (conductive and insulating)

IEC 62899-202-4:2021(E) defines the terminology and measurement methods for the properties of stretchable printed layers, such as conductive ink, for forming stretchable conductors by printing, stretchable conductive films obtained from conductive ink, and stretchable printed wiring consisted by conductive ink with insulator.
Stretchable printed layers (conductive and insulating) handled by this document apply to the stretchable electric wiring printed on stretchable substrates, for example fabric integrated wearable devices, skin patchable devices, and so on.

General Information

• Status: Published
• Publication Date: 21-Oct-2021
• ICS: 31.180 - Printed circuits and boards
• ICS: 87.080 - Inks. Printing inks
• Technical Committee: TC 119 - Printed Electronics
• Drafting Committee: WG 2 - TC 119/WG 2
• Current Stage: PPUB - Publication issued
• Start Date: 19-Nov-2021
• Completion Date: 22-Oct-2021

Overview

IEC 62899-202-4:2021 is an international standard in the Printed Electronics series that specifies terminology and measurement methods for properties of stretchable printed layers (conductive and insulating). It focuses on the test methods used to evaluate printed stretchable conductive inks and insulating layers intended for stretchable wiring on substrates such as textiles and skin-contact devices (e.g., fabric-integrated wearables and skin‑patchable electronics).

Key topics and technical requirements

The standard provides structured, reproducible measurement methods and reporting requirements for stretchable printed layers. Major technical topics include:

• Stretch dependence of resistance
  • Methods for measuring how electrical resistance of printed conductive layers changes under strain, including step-by-step (static) and cyclic (dynamic) stretch tests. Test-piece geometries (I-shape and U-shape) and required test setups are defined.
• Durability tests
  • Washing durability (test pieces with cover insulators) and sweat durability-procedures to assess functionality after exposure to laundering or artificial sweat.
• Insulation performance
  • Insulation resistance and electric strength tests between conductive lines, for cover insulation side and substrate side, with defined test pieces and measurement circuits.
• Atmospheric and conditioning requirements
  • Reference to standard atmospheric conditions for measurements and conditioning prior to testing.
• Reporting and normative references
  • Guidance on how to document results and which related standards to use for specific electrical or dielectric measurements.

The document cross-references relevant standards such as IEC 60243-1, IEC 61557-2, IEC 62631-3-1 and the parent IEC 62899-202 series.

Practical applications and target users

IEC 62899-202-4:2021 is essential for organizations developing, testing or certifying stretchable printed electronics:

• Conductive ink manufacturers - to validate ink performance under mechanical deformation and environmental exposure.
• Printed electronics test laboratories - to implement standardized test methods for reproducible data and customer reporting.
• Wearable device designers and textile engineers - to select and qualify printed conductive and insulating layers for garments, patches and skin-contact systems.
• Quality assurance and regulatory teams - to support compliance, reliability assessments and supplier specifications.

Using these methods helps predict device lifetime, ensure electrical safety, and improve comparability of materials across suppliers.

Related standards

• IEC 62899-202 (parent specification for conductive ink)
• IEC 60243-1 (electric strength of insulating materials)
• IEC 61557-2 (insulation resistance testing)
• IEC 62631-3-1 (dielectric and resistive properties)
• ISO 105-C10 (textile color fastness – referenced for washing conditions)

Keywords: IEC 62899-202-4:2021, printed electronics, stretchable conductive ink, measurement methods, stretchable printed layers, insulation resistance, electric strength, wearable devices.

Standards Content (Sample)

IEC 62899-202-4 ®
Edition 1.0 2021-10
INTERNATIONAL
STANDARD
colour
inside
Printed electronics –
Part 202-4: Materials – Conductive ink – Measurement methods for properties
of stretchable printed layers (conductive and insulating)
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IEC 62899-202-4 ®
Edition 1.0 2021-10
INTERNATIONAL
STANDARD
colour
inside
Printed electronics –
Part 202-4: Materials – Conductive ink – Measurement methods for properties

of stretchable printed layers (conductive and insulating)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.180; 87.080 ISBN 978-2-8322-1040-3

– 2 – IEC 62899-202-4:2021 © IEC 2021
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Atmospheric conditions for measurement and conditioning . 8
5 Measurement methods of properties of stretchable conductive inks . 8
6 Measurement methods of properties of stretchable conductive layers . 9
6.1 Stretch dependence of the conductive layer's resistance . 9
6.1.1 General . 9
6.1.2 Test piece . 9
6.1.3 Equipment and tools . 10
6.1.4 Step-by-step stretch test (static) . 12
6.1.5 Cyclic stretch test (dynamic) . 13
6.2 Washing durability . 14
6.2.1 Test method and condition . 14
6.2.2 Test piece type A with cover insulator . 14
6.2.3 Test piece type B with cover insulator . 15
6.2.4 Reporting of the results . 15
6.3 Sweat durability . 16
6.3.1 Test method and condition . 16
6.3.2 Test piece . 16
6.3.3 Reporting of the results . 16
7 Measurement methods of insulation between conductive lines . 16
7.1 Insulation resistance between conductive lines . 16
7.1.1 Test piece . 16
7.1.2 Procedure . 16
7.1.3 Reporting of the results . 17
7.2 Electric strength between conductive lines . 17
7.2.1 Test piece . 17
7.2.2 Procedure . 17
7.2.3 Reporting of the results . 18
7.3 Insulation resistance of cover insulation layer side . 18
7.3.1 Test piece . 18
7.3.2 Procedure . 19
7.3.3 Reporting of the results . 21
7.4 Electric strength of cover insulation side . 21
7.4.1 Test piece . 21
7.4.2 Procedure . 21
7.4.3 Reporting of the results . 21
7.5 Insulation resistance of the substrate side . 21
7.5.1 Test piece . 21
7.5.2 Procedure . 21
7.5.3 Reporting of the results . 22
7.6 Electric strength of substrate side . 22
7.6.1 Test piece . 22

7.6.2 Procedure . 22
7.6.3 Reporting of the results . 22
Bibliography . 23

Figure 1 – Test piece type A (I-shape test piece) . 9
Figure 2 – Test piece type B (U-shape test piece) . 10
Figure 3 – Setting and circuit for the test piece type A . 11
Figure 4 – Setting and circuit for the test piece type B . 12
Figure 5 – Example of test piece being stretched (test piece type A) . 13
Figure 6 – Test piece type A with cover insulator . 15
Figure 7 – Test piece type B with cover insulator . 15
Figure 8 – Test piece for insulation resistance between conductive lines . 17
Figure 9 – Test piece for electric strength between conductive lines . 18
Figure 10 – Test piece for insulation resistance of insulating layer . 19
Figure 11 – Setting for the test piece . 20
Figure 12 – Setting and circuit for cover insulation layer . 20
Figure 13 – Setting and circuit for insulation resistance of substrate . 22

– 4 – IEC 62899-202-4:2021 © IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PRINTED ELECTRONICS –
Part 202-4: Materials – Conductive ink – Measurement methods
for properties of stretchable printed layers (conductive and insulating)

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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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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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 62899-202-4 has been prepared by IEC technical committee 119:
Printed electronics.
This International Standard is to be used in conjunction with IEC 62899-202:2016.
The text of this International Standard is based on the following documents:
Draft Report on voting
119/370/FDIS 119/376/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.

This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement,
available at www.iec.ch/members_experts/refdocs. The main document types developed by
IEC are described in greater detail at www.iec.ch/standardsdev/publications.
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 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 document 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 62899-202-4:2021 © IEC 2021
INTRODUCTION
The IEC 62899-20x series relates mainly to measurement methods for materials of printed
electronics. The series also includes storage methods, packaging and marking, and
transportation conditions.
The IEC 62899-20x series is divided into parts for each material. Each part is prepared as a
generic specification containing fundamental information for the area of printed electronics.
The IEC 62899-20x series consists of the following parts:
Part 201: Materials – Substrates
Part 201-2: Materials – Substrates – Measurement methods for properties of stretchable
substrates
Part 202: Materials – Conductive ink
Part 202-3: Materials – Conductive ink – Measurement of sheet resistance of conductive
films – Contactless method
Part 202-4: Materials – Conductive ink – Measurement methods for properties of
stretchable printed layers (conductive and insulating)
Part 202-5: Materials – Conductive ink – Mechanical bending test of a printed conductive
layer on an insulating substrate
Part 202-6: Materials – Conductive ink – Measurement method for resistance changes
under high temperature and humidity – Printed metal-based conductive layer on a flexible
substrate
Part 202-7: Materials – Printed film – Measurement of peel strength for printed layer on
flexible substrate by the 90° peel method
Part 203: Materials – Semiconductor ink.
Part 204: Materials – Insulator ink – Measurement methods of properties of insulator inks
and printed insulating layers
(Subsequent parts will be prepared for other materials.)
Furthermore, each part will also include sectional specifications, blank detail specifications,
and detail specifications of each material.
This part of IEC 62899 deals with stretchable printed layers (conductive and insulating) used
in printed electronics and contains the test conditions, the measurement methods and the
storage conditions.
PRINTED ELECTRONICS –
Part 202-4: Materials – Conductive ink – Measurement methods
for properties of stretchable printed layers (conductive and insulating)

1 Scope
This part of IEC 62899 defines the terminology and measurement methods for the properties
of stretchable printed layers, such as conductive ink, for forming stretchable conductors by
printing, stretchable conductive films obtained from conductive ink, and stretchable printed
wiring consisted by conductive ink with insulator.
Stretchable printed layers (conductive and insulating) handled by this document apply to the
stretchable electric wiring printed on stretchable substrates, for example fabric integrated
wearable devices, skin patchable devices, and so on.
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 60243-1, Electric strength of insulating materials – Test methods – Part 1: Tests at power
frequencies
IEC 61557-2, Electrical safety in low voltage distribution systems up to 1 000 V AC and
1 500 V DC – Equipment for testing, measuring or monitoring of protective measures – Part 2:
Insulation resistance
IEC 62631-3-1, Dielectric and resistive properties of solid insulating materials – Part 3-1:
Determination of resistive properties (DC methods) – Volume resistance and volume
resistivity – General method
IEC 62899-202, Printed electronics – Part 202: Materials – Conductive ink
ISO 105-C10, Textiles – Tests for colour fastness – Part C10: Colour fastness to washing with
soap or soap and soda
ISO 105-E04, Textiles – Tests for colour fastness – Part E04: Colour fastness to perspiration
ISO 291, Plastics – Standard atmospheres for conditioning and testing
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/

– 8 – IEC 62899-202-4:2021 © IEC 2021
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
stretchable substrate
substrate material (e.g., plastic sheet) that can be mechanically deformed by applying tensile
loading (stress) and that exhibits reversible mechanical behaviour (elastic deformation) up to
at least 10 % tensile strain
Note 1 to entry: In this document, the stretchable substrate is used to evaluate stretchable conductive layers and
insulating layers.
[SOURCE: IEC 62899-101:2019, 3.132, modified – the note has been added.]
3.2
stretchable insulator
electric insulator (typically in the form of a film) that exhibits a decrease in resistivity of less
than 10 % during mechanical deformation up to at least 10 % tensile strain
[SOURCE: IEC 62899-101:2019, 3.131]
3.3
stretchable cover lay film
electrically insulating film made from a stretchable insulator and used as cover layer for
stretchable conductors
[SOURCE: IEC 62899-101:2019, 3.130]
3.4
stretchable conductor
electric conductor that exhibits a decrease in conductivity of less than 10 % during
mechanical deformation up to at least 10 % tensile strain
[SOURCE: IEC
...