IEC TR 62899-402-4:2021

IEC TR 62899-402-4 ®
Edition 1.0 2021-09
TECHNICAL
REPORT
colour
inside
Printed electronics –
Part 402-4: Printability – Measurement of qualities – Classification and
measurement methods for morphology
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.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
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 corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC online collection - oc.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always
committee, …). It also gives information on projects, replaced have access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 000 terminological entries in English
details all new publications released. Available online and
and French, with equivalent terms in 18 additional languages.
once a month by email.
Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc

If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC TR 62899-402-4 ®
Edition 1.0 2021-09
TECHNICAL
REPORT
colour
inside
Printed electronics –
Part 402-4: Printability – Measurement of qualities – Classification and

measurement methods for morphology

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.180 ISBN 978-2-8322-1024-7

– 2 – IEC TR 62899-402-4:2021  IEC 2021
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Classification of surface forms for future standardization work . 7
5 ISO documents concerning surface roughness . 8
6 Examples of measurement . 9
6.1 Micro surface roughness of the printed pattern . 9
6.1.1 AFM approach . 9
6.1.2 Shape of the droplet on substrates using inkjet printing . 12
6.2 Thickness of the printed pattern (improved thickness) . 13
6.2.1 Measurement of trapezoid and semi ellipse . 13
6.2.2 Measurement of side horn . 14
6.3 Roughness for the printed conductive line . 14
7 Suggestions for future standardization on morphology . 16
Bibliography . 17

Figure 1 – Typical pattern profile. 6
Figure 2 – Classification of parameters and future standardization work in TC 119 . 7
Figure 3 – Flow of data processing and related standards . 8
Figure 4 – AFM image of NWCNT printed pattern . 9
Figure 5 – Three-dimensional AFM nanoscale surface images and parameters . 10
Figure 6 – Surface image of printed electrode and sensor and grain size distribution
histogram on working surface of SPCE, SPCE-Chi, and SPCE-Chi-GST at 1 μm x 1
μm AFM scan size . 11
Figure 7 – Example of "side horns" . 13
Figure 8 – Electrode formed by gravure offset printing . 14
Figure 9 – An example of roughness in the cross-section in the width direction of a
printed line . 15
Figure 10 – An example of average value of the cross section area . 16

Table 1 – The ISO standards related to the surface roughness . 8
Table 2 – Surface grain structure estimation on a working platform . 10
Table 3 – R-parameters exploration from AFM micrographs at 1 μm x1 μm scan size . 12

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PRINTED ELECTRONICS –
Part 402-4: Printability – Measurement of qualities –
Classification and measurement methods for morphology

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.
IEC TR 62899-402-4 has been prepared by IEC technical committee 119: Printed Electronics.
It is a Technical Report.
The text of this Technical Report is based on the following documents:
Draft Report on voting
119/300/DTR 119/357/RVDTR
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 Technical Report is English.

– 4 – IEC TR 62899-402-4:2021  IEC 2021
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.
INTRODUCTION
The IEC 62899-402 series specifies basic measurement methods for printed patterns prepared
using printed electronics technology. An overview of the documents in the IEC 62899-402 series
is given in IEC 62899-401.
Since the surface morphologies of printed patterns strongly affect the electrical properties of
patterns as well as the printing process such as overlay printing onto the patterns, IEC TC 119
plans to prepare other documents to measure the vertical variance of printed patterns, such as
the future IEC 62899-402-5 which deals with “‘surface roughness”, the future IEC 62899-402-6
which deals with “thickness” and the future IEC 62899-402-7 which deals with ”surface profile”’.
These future documents were designed based on assumptions from classical technologies such
as photolithography. However, the cross section of patterns by photolithography has usually a
trapezoidal or rectangular shape, and the surface of the patterns is always flat and smooth. In
contrast, the actual surface of the printed pattern has various morphologies, because the
characteristic surface morphologies are formed by the various printing technologies used in
printed electronics, and factors that cannot be controlled perfectly are included in the process
of forming the surface. Reflecting those features, the range of variance to be measured in the
area of printed electronics becomes very broad, and various measurement methods are used
in those measurements. In order to prepare the subsequent documents, the current
measurement methods should be reviewed in a technical report. This review will clarify the
relation between the morphologies and the appropriate measurement methods.
According to the complicated surface morphologies, it is not easy to specify the measuring point
on the surface. This problem will also be reviewed in this document by organizing the definitions
of morphologies.
– 6 – IEC TR 62899-402-4:2021  IEC 2021
PRINTED ELECTRONICS –
Part 402-4: Printability – Measurement of qualities –
Classification and measurement methods for morphology

1 Scope
This part of IEC 62899-402, which is a Technical Report, is a preparatory work for the
documents dealing with the measurement method of the vertical direction (surface forms) of
printed patterns made by printed electronics technology.
The printed pattern of interest in this document is limited to straight lines on substrates with a
flat surface. This document focuses on the classification and measurement methods for surface
forms from the nanometer scale to the micrometer scale, and suggests the strategy for the
subsequent documents.
2 Normative references
There are no normative references in this document.
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/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
pattern profile
characteristics of the cross sectional form in the width direction
Note 1 to entry: Three shapes, ie trapezoid, arch and side horn are proposed as typical shapes (see Figure 1).

Figure 1 – Typical pattern profile
Note 2 to entry: The side horn shape is called coffee stain in the academic area. However side horn is used in this
document.
3.2
micro surface roughness of the printed pattern
amplitude and short-wavelength (less than 10 µm) component of the surface

3.3
thickness of the printed pattern
improved thickness
maximum distance between the top surface and bottom side in the width direction of the printed
pattern
3.4
pattern roughness in the line direction
variation in thickness in the line direction
4 Classification of surface forms for future standardization work
Surface forms can be classified as shown in Figure 2. "Pattern micro roughness" expresses the
finest unevenness (less than 5 µm) on the surface of the printed lines. "Pattern profile" includes
a larger unevenness (from 5 µm to 200 µm). The area of "Pattern roughness" (or waviness)
overlaps "Pattern profile", but this shows the waviness with a long range frequency and can be
separated from the fine unevenness. "Pattern thickness" can be based on a different concept
than the above three parameters, but it is also added to Figure 2 since it has a deep relation
with these parameters.
Standards on the measurements for the vertical direction can be prepared according to this
classification.
Figure 2 – Classification of parameters and future standardization work in TC 119

– 8 – IEC TR 62899-402-4:2021  IEC 2021
5 ISO documents concerning surface roughness
ISO/TC 213 (Dimensional and geometrical product specifications and verification) is a TC that
handles product dimensions and tolerances. Since the surface roughness is one of the factors
that affects them, ISO/TC 213 has prepared many standards related to the surface roughness
such as data processing, definitions of terms (see Figure 3). However, it is not possible to find
a document for the measurement method that can be directly used in the printed electronics
industry. The summary of the ISO standards is listed in Table 1.

Figure 3 – Flow of data processing and related standards
Table 1 – The ISO standards related to the surface roughness
Document No Title Brief summary
ISO 1302 [8] Geometrical Product Specifications This d
...