EN IEC 62435-4:2018

SLOVENSKI STANDARD
01-oktober-2018
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Electronic components - Long-term storage of electronic semiconductor devices - Part 4:
Storage (IEC 62435-4:2018)
Ta slovenski standard je istoveten z: EN IEC 62435-4:2018
ICS:
31.080.01 Polprevodniški elementi Semiconductor devices in
(naprave) na splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 62435-4

NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2018
ICS 31.020
English Version
Electronic components - Long-term storage of electronic
semiconductor devices - Part 4: Storage
(IEC 62435-4:2018)
Composants électroniques - Stockage de longue durée des Elektronische Bauteile - Langzeitlagerung elektronischer
dispositifs électroniques à semiconducteurs - Part 4: Halbleiterbauelemente - Teil 4: Lagerung
Stockage (IEC 62435-4:2018)
(IEC 62435-4:2018)
This European Standard was approved by CENELEC on 2018-07-10. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 62435-4:2018 E

European foreword
The text of document 47/2469/FDIS, future edition 1 of IEC 62435-4, prepared by IEC/TC 47
"Semiconductor devices" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 62435-4:2018.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2019-04-10
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2021-07-10
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
Endorsement notice
The text of the International Standard IEC 62435-4:2018 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 60068-2-17 NOTE Harmonized as EN 60068-2-17
IEC 60721-3-1 NOTE Harmonized as EN IEC 60721-3-1
IEC 60749-30 NOTE Harmonized as EN 60749-30
IEC 61340-5-1 NOTE Harmonized as EN 61340-5-1
IEC 61340-5-3 NOTE Harmonized as EN 61340-5-3
IEC 61760-2 NOTE Harmonized as EN 61760-2
IEC 62258 series NOTE Harmonized as EN 62258 series
IEC 62435 series NOTE Harmonized as EN 62435 series
IEC 62435-2 NOTE Harmonized as EN 62435-2

Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is
available here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60749-20-1 -  Semiconductor devices - Mechanical and EN 60749-20-1 -
climatic test methods - Part 20-1: Handling,
packing, labelling and shipping of surface-
mount devices sensitive to the combined
effect of moisture and soldering heat
IEC/TR 61340-5-2 -  Electrostatics -- Part 5-2: Protection of CLC/TR 61340-5-2 -
electronic devices from electrostatic
phenomena - User guide
IEC/TR 62258-3 -  Semiconductor die products -- Part 3: - -
Recommendations for good practice in
handling, packing and storage
JEDEC J-STD-033 - Standard for handling, packing, shipping,
and use of moisture/reflow sensitive
surface mount devices
MIL-PRF-27401 - Propellant pressurizing agent nitrogen
MIL-PRF-81705 - ESD Materials, Bags and Performance
Specification
IEC 62435-4 ®
Edition 1.0 2018-06
INTERNATIONAL
STANDARD
Electronic components – Long-term storage of electronic semiconductor

devices –
Part 4: Storage
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.020 ISBN 978-2-8322-5768-5

– 2 – IEC 62435-4:2018 © IEC 2018
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 Purpose of storage (facility) . 10
4.1 General . 10
4.2 Cost of ownership . 10
4.3 Security . 10
4.4 Location and ambient environment . 10
4.5 Incorrect control of reliability during storage . 10
5 Storage . 10
5.1 General . 10
5.2 Type of environment . 11
5.3 Storage identification – traceability . 11
5.4 Initial packaging . 11
5.5 Storage conditions . 12
5.5.1 General . 12
5.5.2 Storage area . 12
5.6 Maintaining storage conditions . 13
6 Periodic check of the components . 13
6.1 Objectives . 13
6.2 Periodicity . 13
6.3 Tests during periodic check . 14
7 Removal from storage . 14
7.1 Precautions . 14
7.2 Electrostatic discharges . 14
8 Materials used in storage regimes . 14
8.1 General . 14
8.2 Moisture barrier bags (MBB) . 14
8.3 Desiccant . 15
8.4 Humidity indicator card (HIC) . 15
8.5 Dry nitrogen atmosphere . 15
8.6 High purity dry air atmosphere . 15
8.7 Storage containers . 16
8.8 Foams, packing material and protective cushioning . 16
9 General storage environment . 16
10 LTS methods . 16
10.1 General . 16
10.2 Dry cabinet storage . 17
10.2.1 General . 17
10.2.2 Humidity controlled storage . 17
10.2.3 Oxygen (O )-controlled storage . 17
10.2.4 Outgassing-controlled storage . 17
10.3 MBB storage . 17
10.3.1 General . 17

IEC 62435-4:2018 © IEC 2018 – 3 –
10.3.2 Humidity-controlled storage . 17
10.3.3 Oxygen (O )-voided storage . 17
10.3.4 Outgassing controlled storage . 18
10.3.5 Nitrogen (N ) positive-pressure MBB storage . 18
11 LTS double containment redundancy . 18
Annex A (normative) Example checklist for long-term storage facilities . 19
Bibliography . 20

Table A.1 – Example checklist for storage facilities . 19

– 4 – IEC 62435-4:2018 © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRONIC COMPONENTS – LONG-TERM STORAGE
OF ELECTRONIC SEMICONDUCTOR DEVICES –

Part 4: Storage
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.
International Standard IEC 62435-4 has been prepared by IEC technical committee 47:
Semiconductor devices.
The text of this International Standard is based on the following documents:
FDIS Report on voting
47/2469/FDIS 47/2486/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.

IEC 62435-4:2018 © IEC 2018 – 5 –
A list of all parts in the IEC 62435 series, published under the general title Electronic
components – Long-term storage of electronic semiconductor devices, 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.

– 6 – IEC 62435-4:2018 © IEC 2018
INTRODUCTION
This standard applies to the long-term storage of electronic components.
This is a standard for long-term storage (LTS) of electronic devices drawing on the best long-
term storage practices currently known. For the purposes of this document, LTS is defined as
any device storage whose duration may be more than 12 months for products scheduled for
long duration storage. While intended to address the storage of unpackaged semiconductors
and packaged electronic devices, nothing in this document precludes the storage of other
items under the storage levels defined herein.
Although it has always existed to some extent, obsolescence of electronic components and
particularly of integrated circuits, has become increasingly intense over the last few years.
Indeed, with the existing technological boom, the commercial life of a component has become
very short compared with the life of industrial equipment such as that encountered in the
aeronautical field, the railway industry or the energy sector.
The many solutions enabling obsolescence to be resolved are now identified. However,
selection of one of these solutions should be preceded by a case-by-case technical and
economic feasibility study, depending on whether storage is envisaged for field service or
production, for example:
• remedial storage as soon as components are no longer marketed;
• preventative storage anticipating declaration of obsolescence.
Taking into account the expected life of some installations, sometimes covering several
decades, the qualification times and the unavailability costs, which can also be very high, the
solution to be adopted to resolve obsolescence should often be rapidly implemented. This is
why the solution retained in most cases consists in systematically storing components which
are in the process of becoming obsolescent.
The technical risks of this solution are, a priori, fairly low. However, it requires perfect mastery
of the implemented process and especially of the storage environment, although this mastery
becomes critical when it comes to long-term storage.
All handling, protection, storage and test operations are recommended to be performed
according to the state of the art.
The application of the approach proposed in this document in no way guarantees that the
stored components are in perfect operating condition at the end of this storage. It only
comprises a means of minimizing potential and probable degradation factors.
Some electronic device users have the need to store electronic devices for long periods of
time. Lifetime buys are commonly made to support production runs of assemblies that well
exceed the production timeframe of their individual parts. This puts the user in a situation
requiring careful and adequate storage of such parts to maintain the as-received solderability
and to minimize any degradation effects to the part over time. Major degradation concerns are
moisture, electrostatic fields, ultra-violet light, large variations in temperature, air-borne
contaminants and outgassing.
Warranties and sparing also present a challenge for the user or repair agency, as some
systems have been designated to be used for long periods of time, in some cases for up to
40 years or more. Some of the devices needed for repair of these systems will not be
available from the original supplier for the lifetime of the system, or the spare assembly can
be built with the original production run but then require long-term storage. This document
was developed to provide a standard for storing electronic devices for long periods of time.

IEC 62435-4:2018 © IEC 2018 – 7 –
The storage of devices that are moisture sensitive but that do not need to be stored for long
periods of time is dealt with in IEC TR 62258-3.
Long-term storage assumes that the device is going to be placed in uninterrupted storage for
a number of years. It is essential that it be useable after storage. It is important that storage
media and the local environment are considered together.
These guidelines do not imply any warranty of product or guarantee of operation beyond the
storage time given by the manufacturer.
The IEC 62435 series is intended to ensure that adequate reliability is achieved for devices in
user applications after long-term storage. Users are encouraged to request data from
suppliers to applicable specifications to demonstrate a successful storage life as requested by
the user. These standards are not intended to address built-in failure mechanisms that would
take place regardless of storage conditions.
These standards are intended to give practical guidance on methods of long-duration storage
of electronic components, where this is intentional or involves planned storage of a product
for a number of years. Storage regimes for work-in-progress production are managed
according to company internal process requirements and are not detailed in this series of
standards.
The overall standard series is split into a number of parts. Parts 1 to 4 apply to any long-term
storage and contain general requirements and guidance, whereas Parts 5 to 9 are specific to
the type of product being stored.
Electronic components requiring different storage conditions are covered separately starting
with Part 5.
The structure of the IEC 62435 series as currently planned consists of the following:
Part 1 – General
Part 2 – Deterioration mechanisms
Part 3 – Data
Part 4 – Storage
Part 5 – Die and wafer devices
Part 6 – Packaged or finished devices
Part 7 – MEMS
Part 8 – Passive electronic devices
Part 9 – Special cases
– 8 – IEC 62435-4:2018 © IEC 2018
ELECTRONIC COMPONENTS – LONG-TERM STORAGE
OF ELECTRONIC SEMICONDUCTOR DEVICES –

Part 4: Storage
1 Scope
This part of IEC 62435 specifies long-term storage methods and recommended conditions for
long-term storage of electronic components including logistics, controls and security related to
the storage facility. Long-term storage refers to a duration that may be more than 12 months
for products scheduled for long duration storage. The philosophy of such storage, good
working practices and general means to facilitate the successful long-term storage of
electronic components are also addressed.
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 60749-20-1, Semiconductor devices – Mechanical and climatic test methods – Part 20-1:
Handling, packing, labelling and shipping of surface-mount devices sensitive to the combined
effect of moisture and soldering heat
IEC TR 62258-3, Semiconductor die products – Part 3: Recommendations for good practice in
handling, packing and storage
IEC 61340-5-2, Electrostatics – Part 5-2: Protection of electronic devices from electrostatic
phenomena – User guide
JEDEC J-STD-033, Standard for handling, packing, shipping, and use of moisture/reflow
sensitive surface mount devices
MIL-PRF-27401, Propellant pressurizing agent nitrogen
MIL-PRF-81705, ESD Materials, Bags and Performance Specification
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
storage environment
specially controlled storage area, with particular control of temperature, humidity, atmosphere
and any other conditions depending on the product requirements

IEC 62435-4:2018 © IEC 2018 – 9 –
3.2
moisture sensitivity level
MSL
rated and verified moisture sensitivity level assigned to a component that defines the
maximum safe equilibrium moisture exposure for a specific encapsulated device prior to
reflow assembly or rework
3.3
long-term storage
LTS
planned storage of components to extend the life-cycle for a duration with the intention of
supporting future use
3.4
LTS storeroom
area containing components that have additional packaging for storage to protect from
moisture or from mechanical impact or for ease of identification or handling
3.5
moisture-sensitive device
MSD
device that has moisture absorption or moisture retention and whose quality or reliability is
affected by moisture
3.6
electronic device
packaged electrical, electronic, electro-mechanical (EEE) item, or assemblies using such
items
[SOURCE: IEC 60050-551:1998, 551-14-01, modified]
3.7
desiccant
hygroscopic substance used to remove moisture from an atmosphere
3.8
moisture barrier bag
MBB
storage bag manufactured with a flexible laminated vapour barrier film that restricts the
transmission of water vapour
Note 1 to entry: Refer to IEC 60749-20-1 for packaging of moisture sensitive products.
3.9
humidity indicator card
HIC
card printed with a moisture sensitive chemical that changes from blue to pink in the presence
of water vapour
3.10
water vapour transmission rate
WVTR
measure of permeability of MBBs to water vapour
3.11
electrostatic discharge
ESD
transfer of electric charge between bodies of different electrostatic potentials in proximity or
through direct contact
[SOURCE: IEC 60050-561:2014, 561-03-06]

– 10 – IEC 62435-4:2018 © IEC 2018
4 Purpose of storage (facility)
4.1 General
Successful long-term storage is dependent upon sustained control of the environment and its
physical and data security. Costs associated with handling, maintaining traceability, physical
accounting and environmental conditions should be accounted for from the outset of long-term
storage.
4.2 Cost of ownership
Cost will be determined by type of storage facility, cabinet, continuous nitrogen flow or inert
gas flow and periodical examination on a repres
...