IEC 62435-8:2020

Electronic components - Long-term storage of electronic semiconductor devices - Part 8: Passive electronic devices

IEC 62435-8:2020 on long-term storage is applied to passive electronic devices in long-term storage that can be used as part of obsolescence mitigation strategy. Long-term storage refers to a duration that can be more than 12 months for product scheduled for storage. Storage typically begins when components are packed at the originating supplier where the pack date or date code are assigned to the product. It is the responsibility of the distributor and the customer to control and manage the aging inventory upon receipt of the dated product. Alternatively, a supplier-customer agreement can be established to manage the aging inventory. Philosophy, good working practice, and general means to facilitate the successful long-term storage of electronic components are also addressed.

Composants électroniques - Stockage de longue durée des dispositifs électroniques à semiconducteurs - Partie 8 : Dispositifs électroniques passifs

IEC 62435-8:2020 relative au stockage de longue durée s’applique aux dispositifs électroniques passifs à stockage de longue durée qui peuvent être utilisés dans le cadre d’une stratégie de réduction de l’obsolescence. Le stockage de longue durée fait référence à une durée qui peut être supérieure à 12 mois, pour un produit destiné à être stocké. Le stockage commence généralement avec l’emballage des composants dans les locaux du fournisseur d’origine et l’attribution au produit de la date d’emballage ou du code de date. Le distributeur et le client sont tenus de contrôler et gérer le stock des produits vieillissants à réception du produit marqué d’une date. En variante, un accord fournisseur‑client peut être mis en place pour gérer le stock des produits vieillissants. Les concepts, les bonnes pratiques de travail et les moyens généraux de nature à faciliter les bonnes conditions de stockage de longue durée des composants électroniques sont aussi traités.

Standards Content (sample)

IEC 62435-8
Edition 1.0 2020-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electronic components – Long-term storage of electronic semiconductor
devices –
Part 8: Passive electronic devices
Composants électroniques – Stockage de longue durée des dispositifs
électroniques à semiconducteurs –
Partie 8: Dispositifs électroniques passifs
IEC 62435-8:2020-07(en-fr)
---------------------- Page: 1 ----------------------
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IEC 62435-8
Edition 1.0 2020-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electronic components – Long-term storage of electronic semiconductor
devices –
Part 8: Passive electronic devices
Composants électroniques – Stockage de longue durée des dispositifs
électroniques à semiconducteurs –
Partie 8: Dispositifs électroniques passifs
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.020 ISBN 978-2-8322-8560-2

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Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
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– 2 – IEC 62435-8:2020 © IEC 2020
CONTENTS

FOREWORD ........................................................................................................................... 3

INTRODUCTION ..................................................................................................................... 5

1 Scope .............................................................................................................................. 7

2 Normative references ...................................................................................................... 7

3 Terms and definitions ...................................................................................................... 7

4 Storage considerations .................................................................................................... 9

4.1 Overview of passive components ............................................................................ 9

4.2 Failure mechanisms ................................................................................................ 9

4.2.1 Occurrence of failure and driving force ............................................................ 9

4.2.2 Storage environment and mitigation for stimuli to prevent failure ................... 11

4.3 Materials management .......................................................................................... 11

4.4 Storage media ...................................................................................................... 12

4.5 Documentation/paper lot identifiers ....................................................................... 12

4.6 Inventory check..................................................................................................... 12

4.7 Inventory dry packing refreshing ........................................................................... 12

4.8 Inventory re-assessment ....................................................................................... 13

5 Baseline long-term storage requirements ....................................................................... 13

5.1 General ................................................................................................................. 13

5.2 Moisture sensitivity designation ............................................................................ 13

5.3 Dry packing for storage ......................................................................................... 13

5.4 Non-moisture sensitive storage ............................................................................. 13

5.4.1 General ......................................................................................................... 13

5.4.2 Storage media ............................................................................................... 13

5.4.3 Lot data and labelling .................................................................................... 13

5.5 Storage of moisture sensitive finished devices ...................................................... 14

5.5.1 Moisture barrier bag ...................................................................................... 14

5.5.2 Dunnage ........................................................................................................ 14

5.5.3 Humidity indicator card .................................................................................. 14

5.5.4 Desiccant ...................................................................................................... 14

5.5.5 Labelling ........................................................................................................ 14

5.5.6 Lot data and labelling .................................................................................... 15

5.5.7 Storage environment ..................................................................................... 15

5.5.8 Process (temperature) sensitivity designation ................................................ 15

Annex A (informative) Passive electronic device storage environment considerations .......... 16

Bibliography .......................................................................................................................... 17

Table 1 – Failure mechanisms in storage and stimuli to mitigate during storage. ................... 10

Table 2 – Long-term environment – sustained condition requirements .................................. 11

Table 3 – Considerations for management, control and documentation during storage .......... 12

Table A.1 – Long-term storage environment – sustained condition considerations ................ 16

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IEC 62435-8:2020 © IEC 2020 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRONIC COMPONENTS – LONG-TERM STORAGE
OF ELECTRONIC SEMICONDUCTOR DEVICES –
Part 8: Passive electronic devices
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 interna-

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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

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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 62435-8 has been prepared by subcommittee IEC technical com-

mittee 47: Semiconductor devices.
The text of this International Standard is based on the following documents:
CDV Report on voting
47/2595/CDV 47/2618/RVC

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.

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– 4 – IEC 62435-8:2020 © IEC 2020

A list of all the 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.
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IEC 62435-8:2020 © IEC 2020 – 5 –
INTRODUCTION
This document applies to the long-term storage of passive 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 can be more than 12 months for product 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 aer-

onautical field, the railway industry or the energy sector.

The many solutions enabling obsolescence to be resolved are now identified. However, se-

lecting 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;
• preventive storage anticipating declaration of obsolescence.

Taking into account the expected life of some installations, sometimes covering several dec-

ades, 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 ac-

cording 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 com-

prises 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 its individual parts. This puts the user in a situation re-

quiring careful and adequate storage of such parts to maintain the as-received solderability

and minimize any degradation effects to the part over time. Major degradation concerns are

moisture, electrostatic fields, ultraviolet light, large variations in temperature, air-borne con-

taminants, and outgassing.

Warranties and sparing also present a challenge for the user or repair agency as some sys-

tems 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 availa-

ble from the original supplier for the lifetime of the system or the spare assembly may be built

with the original production run but then require long-term storage. This document was devel-

oped to provide a standard for storing electronic devices for long periods of time. For storage

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– 6 – IEC 62435-8:2020 © IEC 2020

of devices that are moisture sensitive but that do not need to be stored for long periods of

time, IEC TR 62258-3 can be consulted.

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 is useable after storage. Particular attention should be

paid to storage media surrounding the devices together with the local environment.

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 suppli-

ers 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 guide to methods of long-duration storage of

electronic components where this is intentional or planned storage of 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 is split into a number of parts. Parts 1 to 4 apply to any long-term stor-

age and contain general requirements and guidance, whereas Parts 5 to 9 are specific to the

type of product being stored. It is intended that the product specific part should be read

alongside the general requirements of Parts 1 to 4.

Electronic components requiring different storage conditions are planned to be covered sepa-

rately starting with Part 5.
The structure of the IEC 62435 series as currently conceived is as follows:
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
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IEC 62435-8:2020 © IEC 2020 – 7 –
ELECTRONIC COMPONENTS – LONG-TERM STORAGE
OF ELECTRONIC SEMICONDUCTOR DEVICES –
Part 8: Passive electronic devices
1 Scope

This part of the IEC 62435 series on long-term storage is applied to passive electronic devic-

es in long-term storage that can be used as part of obsolescence mitigation strategy. Long-

term storage refers to a duration that can be more than 12 months for product scheduled for

storage. Storage typically begins when components are packed at the originating supplier

where the pack date or date code are assigned to the product. It is the responsibility of the

distributor and the customer to control and manage the aging inventory upon receipt of the

dated product. Alternatively, a supplier-customer agreement can be established to manage

the aging inventory. Philosophy, good working practice, 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 con-

tent 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, Semiconductor devices – Mechanical and climatic test methods – Part 20: Re-

sistance of plastic encapsulated SMDs to the combined effect of moisture and soldering heat

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 61760-4, Surface mounting technology – Part 4: Classification, packaging, labelling and

handling of moisture sensitive devices

JEDEC J-STD-075, Classification of non-IC electronic components for assembly processes

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 ad-

dresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
passive, adj

qualifies a circuit element or a circuit for which the time integral of

the instantaneous power cannot be negative over any time interval beginning at an instant

before the first supply of electric energy

EXAMPLE Resistor, inductor, capacitor, fuse, magnetic switch, crystal oscillator, diode, led

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– 8 – IEC 62435-8:2020 © IEC 2020

Note 1 to entry: Under periodic conditions, the integration interval can comprise an integral number of periods

instead of beginning at minus infinity.

Note 2 to entry: A passive circuit normally does not contain voltage or current sources.

[SOURCE: IEC 60050-131:2002, 131-11-34, modified – A domain has been specified at the

beginning of the definition and some examples have been added.]
3.2
storage environment

specially controlled storage area, with particular control of temperature, humidity, atmosphere

and any other conditions depending on the product requirements
[SOURCE: IEC 62435-1:2017, 3.1.1]
3.3
critical moisture limit

maximum safe equilibrium moisture content for a specific encapsulated device at reflow as-

sembly or rework
3.4
long-term storage
LTS

planned storage of components to extend the life-cycle for a duration with the intention of

supporting future use

Note 1 to entry: Allowable storage durations will vary by form factor (e.g., packing materials, shape) and storage

conditions. In general, long-term storage is longer than 12 months.
[SOURCE: IEC 62435-1:2017, 3.1.2]
3.5
LTS storeroom

area containing components that have additional packaging for storage to protect from mois-

ture or from mechanical impact or for ease of identification or handling
3.6
moisture-sensitive device
MSD

device that has moisture absorption or moisture retention and whose quality or reliability is

affected by moisture
3.7
electronic device

packaged electrical, electronic, electro-mechanical (EEE) item, or assemblies using such

items
[SOURCE: IEC 62435-1:2017, 3.1.3]
3.8
desiccant
hygroscopic substance used to remove moisture from an atmosphere
3.9
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.

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IEC 62435-8:2020 © IEC 2020 – 9 –
[SOURCE: IEC 62435-1:2017, 3.1.4]
3.10
humidity indicator card
HIC

card printed with a moisture sensitive chemical that changes from blue to pink in the presence

of water vapour

[SOURCE: IEC 62435-1:2017, 3.1.5, modified – The bracketed information "(cobalt bromide)"

has been removed from the definition.]
3.11
water vapour transmission rate
WVTR
measure of permeability of MBBs to water vapour
3.12
dunnage

all the matter stored in a moisture barrier bag that is additional to the packaged electronic

component
3.13
electro-static 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]
4 Storage considerations
4.1 Overview of passive components

Passive components are not able to control current where the instantaneous power cannot be

negative therefore there is no power gain before the application of electric energy. Common

examples of passives are resistors, capacitors, inductors, transformers and diodes of all

types. Often electromechanical relays, quartz crystals and fuses are also to be considered

passive components for the purpose of long-term storage requirements. Passive components

are made using a wide range of technologies, materials and manufacturing processes.

Passive components are surface mounted to electronic packages, modules and boards as ei-

ther discrete components or packaged components that vary in size, typically larger than

1 mm in the smallest dimension. Passive miniaturization has led to packaged passives. Pas-

sives are also integrated or embedded into other packaged components, modules and boards.

Passive components can experience many of the same failure modes as other components

and the storage program should consider the end use and failure mechanisms related to the

function of the component. An example list below may be used as a basis for consideration in

storage related risk assessments.
4.2 Failure mechanisms
4.2.1 Occurrence of failure and driving force

Failures during long-term storage should be mitigated by control of the stimuli driving given

failure modes of interest as defined by a failure modes and effects analysis (FMEA). Storage

related failures are often detected as modes of non-operation, visual quality or other non-

conformance. The modes of failure during storage are typically related to a failure mechanism

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– 10 – IEC 62435-8:2020 © IEC 2020

that is driven by a physical stimuli or condition. Successful long-term storage is accomplished

by controlling the failure mechanism stimuli as identified using a failure modes and effect

analysis based on information from technology development and testing. Example failure

stimuli are given in Table 1. Additional examples of deterioration mechanisms are found in

IEC 62435-2. Successful long-term storage is accomplished by mitigating failures through

control of the stimuli or driving force.
Table 1 – Failure mechanisms in storage and stimuli to mitigate during storage.
Failure Failure mechanism detail Failure mode Mechanism stimuli
mechanism

Popcorn effect High rate vapour expansion Open circuit, blistering, com- Temperature increase lead-

within a passive during sur- ponent cracks or parametric ing to moisture vapour
face mounting electrical degradation
Handling Cracking Open, short, visible crack Application of force
damage
Visible scratch/smudge Open, short, surface mark Mechanical abrasion

Staining Change in surface appear- Visible defect, non- Exposure resulting in agi

...