IEC 62951-8:2023

IEC 62951-8 ®
Edition 1.0 2023-01
INTERNATIONAL
STANDARD
colour
inside
Semiconductor devices – Flexible and stretchable semiconductor devices –
Part 8: Test method for stretchability, flexibility, and stability of flexible resistive
memory
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IEC 62951-8 ®
Edition 1.0 2023-01
INTERNATIONAL
STANDARD
colour
inside
Semiconductor devices – Flexible and stretchable semiconductor devices –

Part 8: Test method for stretchability, flexibility, and stability of flexible resistive

memory
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.080.99 ISBN 978-2-8322-6333-4

– 2 – IEC 62951-8:2023 © IEC 2023
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Test method . 6
4.1 General . 6
4.2 Test equipment and tools . 6
4.3 Test procedures . 8
4.3.1 Stretchability test . 8
4.3.2 Flexibility test . 9
4.3.3 Stability testing . 10
4.4 Test report . 11
Annex A (informative) Induced strain on a substrate due to bending . 12
A.1 Detailed derivation of the strain formula by bending . 12
A.2 Simulation results induced strain by bending. 13
Bibliography . 14

Figure 1 – Examples experimental setup for testing stretchability (top) and flexibility
(bottom) . 7
Figure 2 – Schematic for stretchability test denoting parameters before and during
testing . 9
Figure 3 – Schematic for flexibility test denoting parameters before and during testing . 10
Figure A.1 – Deformation of a substrate induced strain by bending . 12
Figure A.2 – Deformation of a substrate induced tensile strain by stretching . 13

Table 1 – Performance parameters of resistive type memory . 6
Table 2 – Example temperature and relative humidity conditions . 11

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SEMICONDUCTOR DEVICES –
FLEXIBLE AND STRETCHABLE SEMICONDUCTOR DEVICES –

Part 8: Test method for stretchability, flexibility,
and stability of flexible resistive memory

FOREWORD
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IEC 62951-8 has been prepared by IEC technical committee 47: Semiconductor devices. It is
an International Standard.
The text of this International standard is based on the following documents:
Draft Report on voting
47/2786/FDIS 47/2793/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
The language used for the development of International Standard is English.

– 4 – IEC 62951-8:2023 © IEC 2023
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 62951 series, published under the general title Semiconductor
devices – Flexible and stretchable semiconductor devices, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until the
stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to
the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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SEMICONDUCTOR DEVICES –
FLEXIBLE AND STRETCHABLE SEMICONDUCTOR DEVICES –

Part 8: Test method for stretchability, flexibility,
and stability of flexible resistive memory

1 Scope
This part of IEC 62951 defines terms and specifies the test method for evaluating the
stretchability, flexibility, and stability of flexible resistive memory. The test method descriptions
include experimental procedures and the equipment to be used. It also includes general
requirements for test conditions such as the temperature and relative humidity of the testing
environment. The test method described in this document focuses on stability evaluation rather
than reliability.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purpose 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 https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
flexible resistive memory
flexible device that works by changing the resistance between dielectric materials
3.2
bending radius
measured to the inside curvature, is the minimum radius one can bend a pipe, tube, sheet,
cable or hose
3.3
resistance of low resistance state
LRS
one of stable resistance states induced by applying higher voltage (unipolar switching) or
positive bias (bipolar switching)
3.4
resistance of high resistance state
HRS
one of stable resistance states induced by applying lower voltage (unipolar switching) or
negative bias (bipolar switching)

– 6 – IEC 62951-8:2023 © IEC 2023
3.5
set voltage
V
set
voltage for switching to low resistance state
3.6
reset voltage
V
reset
voltage for switching to high resistance state
4 Test method
4.1 General
This document applies to flexible resistive memory in order to evaluate its stretchability,
flexibility, and stability. This type of semiconductor device is used mostly in products related to
flexible or wearable electronics, which are often stretched or bent when used. Hence, it is critical
that the main performance parameters of the device be maintained under mechanical
deformation. Detailed performance parameters and characterisation procedures are described
in IEC 62951-1, and Table 1 in this document summarises them as applicable to resistive
memory. This document focuses on experimental methods for testing stretchability, flexibility
and stability, and includes a description of the experimental setup.
One of the most problematic issues in the reliability of resistive memory is its increased
performance degradation rate under mechanical deformation. This deterioration is caused by
cracks in electrodes and the resistive materials used in these types of semiconductor devices.
In particular, degradation is accelerated when cracks occur in the encapsulation layer due to
the stress caused by bending. Therefore, this evaluation suggests an experimental
...