IEC 61760-4:2015

Surface mounting technology - Part 4: Classification, packaging, labelling and handling of moisture sensitive devices

IEC 61760-4:2015 specifies the classification of moisture sensitive devices into moisture sensitivity levels related to soldering heat, and provisions for packaging, labelling and handling. It also extends the classification and packaging methods to such components, where currently existing standards are not required or not appropriate. For such cases this standard introduces additional moisture sensitivity levels and an alternative method for packaging. This standard applies to devices intended for reflow soldering, like surface mount devices, including specific through-hole devices (where the device supplier has specifically documented support for reflow soldering), but not to semiconductor devices and devices for flow (wave) soldering.

Technique du montage en surface (SMT) - Partie 4: Classification, emballage, étiquetage et manipulation des dispositifs sensibles à l'humidité

L'IEC 61760-4:2015 spécifie la classification des dispositifs sensibles à l'humidité en niveaux de sensibilité liés à la chaleur de brasage, ainsi que les dispositions relatives à l'emballage, l'étiquetage et la manipulation. La présente partie de l'IEC 61760 étend les méthodes de classification et d'emballage à ces composants lorsque les normes existantes ne sont pas exigées ou sont inappropriées. Dans ce cas, la présente norme introduit des niveaux de sensibilité à l'humidité supplémentaires ainsi qu'une méthode d'emballage alternative. La présente norme s'applique aux appareils destinés au brasage par refusion, tels que les composants pour montage en surface, y compris les appareils à insertion spécifiques (dont les fournisseurs ont spécifiquement documenté le support pour le brasage par refusion), mais ne s'applique pas aux appareils à semi-conducteurs et aux appareils destinés au brasage à la vague.

General Information

• Status: Published
• Publication Date: 18-May-2015
• ICS: 29.140.40 - Luminaires
• ICS: 31.190 - Electronic component assemblies
• ICS: 37.040.99 - Other standards related to photography
• ICS: 37.060.99 - Other standards related to cinematography
• Technical Committee: TC 91 - Electronics assembly technology
• Drafting Committee: WG 1 - TC 91/WG 1
• Current Stage: PPUB - Publication issued
• Start Date: 19-May-2015
• Completion Date: 15-May-2015

Relations

• Amended By: IEC 61760-4:2015/AMD1:2018 - Amendment 1 - Surface mounting technology - Part 4: Classification, packaging, labelling and handling of moisture sensitive devices
• Effective Date: 05-Sep-2023

Overview

IEC 61760-4:2015 is an international standard developed by the International Electrotechnical Commission (IEC) focused on surface mounting technology. Specifically, it addresses the classification, packaging, labelling, and handling of moisture sensitive devices (MSDs) used in reflow soldering processes. This standard establishes moisture sensitivity levels (MSLs) for electronic components, linked to their tolerance to soldering heat and moisture exposure, ensuring reliable performance in surface mount technology (SMT) manufacturing.

This standard expands on existing moisture sensitivity classifications by introducing additional sensitivity levels and alternative packaging methods, particularly for components where current standards do not apply or are insufficient. IEC 61760-4 is essential for manufacturers, assemblers, and quality assurance professionals dealing with SMT devices to correctly manage moisture sensitivity risks and prevent damage during soldering.

Key Topics

• Moisture Sensitivity Levels (MSL): Defines classification levels for MSDs based on their susceptibility to moisture-induced damage during reflow soldering. These levels guide handling, storage, and processing requirements.

• Packaging Requirements: Specifies packaging processes such as drying, moisture barrier bagging (MBB), use of desiccants, humidity indicators, and sealing techniques to preserve the dryness and integrity of components before use.

• Labelling Protocols: Mandates clear labelling on packaging to communicate moisture sensitivity information. Uses standardized graphical symbols and moisture sensitivity identification/caution labels (MSID/MSCL) to ensure traceability and awareness.

• Handling and Storage: Recommends best practices for storing MSDs, including environmental controls (temperature and humidity), shelf life definitions, floor life limitations, and unpacking/repacking procedures to minimize moisture exposure.

• Moisture Testing and Classification: Details a test procedure involving drying, moisture soak, temperature loading, recovery, and final inspection to accurately classify component sensitivity and verify packaging effectiveness.

Applications

IEC 61760-4:2015 applies primarily to devices intended for reflow soldering such as:

• Surface Mount Devices (SMDs), including resistors, capacitors, inductors, and other passive components.
• Certain through-hole devices that are specifically qualified for reflow soldering by suppliers.

It does not apply to semiconductor devices or devices solely destined for flow (wave) soldering processes. The standard helps ensure component reliability by:

• Preventing "popcorning" and internal damage caused by moisture vaporizing during soldering.
• Facilitating compliance with quality and reliability requirements in SMT assembly lines.
• Enabling manufacturers to implement effective moisture management strategies across supply chains.

This standard is crucial to electronics manufacturing sectors such as consumer electronics, automotive, aerospace, and industrial controls where SMT assemblies require robust moisture sensitivity management to maintain high yield and product lifespan.

Related Standards

• IPC/JEDEC J-STD-020: Provides test methods and classification for moisture sensitive devices, widely used in the electronics industry.
• IEC 61340 Series: Focuses on electrostatic discharge (ESD) control relevant during handling and packaging of MSDs.
• IEC 62137: Addresses packaging methods for electronic components, complementing packaging requirements in IEC 61760-4.
• ISO 14000 Series: Environmental management standards may support storage conditions and handling to reduce moisture-related failures.

These standards collectively support best practices in electronic component moisture sensitivity classification, packaging, testing, and handling, aligning with IEC 61760-4 to ensure product reliability and manufacturing effectiveness.

---

Keywords: IEC 61760-4, moisture sensitive devices, surface mounting technology, moisture sensitivity level, packaging, labelling, handling, reflow soldering, moisture barrier bag, desiccant, humidity indicator, SMT assembly, electronic components, moisture sensitivity classification, MSL, IEC standards.

Standards Content (Sample)

IEC 61760-4 ®
Edition 1.0 2015-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Surface mounting technology –
Part 4: Classification, packaging, labelling and handling of moisture sensitive
devices
Technique du montage en surface (SMT) –
Partie 4: Classification, emballage, étiquetage et manipulation des dispositifs
sensibles à l'humidité
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.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: [phone]
3, rue de Varembé Fax: [phone]
CH-1211 Geneva 20 [e-mail]
Switzerland www.iec.ch
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 corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing more than 30 000 terms and
Technical Specifications, Technical Reports and other definitions in English and French, with equivalent terms in 15
documents. Available for PC, Mac OS, Android Tablets and additional languages. Also known as the International
iPad. Electrotechnical Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a More than 60 000 electrotechnical terminology entries in
variety of criteria (reference number, text, technical English and French extracted from the Terms and Definitions
committee,…). It also gives information on projects, replaced clause of IEC publications issued since 2002. Some entries
and withdrawn publications. have been collected from earlier publications of IEC TC 37,

77, 86 and CISPR.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: [e-mail].
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Catalogue IEC - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
Application autonome pour consulter tous les renseignements
Le premier dictionnaire en ligne de termes électroniques et
bibliographiques sur les Normes internationales,
électriques. Il contient plus de 30 000 termes et définitions en
Spécifications techniques, Rapports techniques et autres
anglais et en français, ainsi que les termes équivalents dans
documents de l'IEC. Disponible pour PC, Mac OS, tablettes
15 langues additionnelles. Egalement appelé Vocabulaire
Android et iPad.
Electrotechnique International (IEV) en ligne.

Recherche de publications IEC - www.iec.ch/searchpub
Glossaire IEC - std.iec.ch/glossary
Plus de 60 000 entrées terminologiques électrotechniques, en
La recherche avancée permet de trouver des publications IEC
en utilisant différents critères (numéro de référence, texte, anglais et en français, extraites des articles Termes et
comité d’études,…). Elle donne aussi des informations sur les Définitions des publications IEC parues depuis 2002. Plus
projets et les publications remplacées ou retirées. certaines entrées antérieures extraites des publications des

CE 37, 77, 86 et CISPR de l'IEC.
IEC Just Published - webstore.iec.ch/justpublished

Service Clients - webstore.iec.ch/csc
Restez informé sur les nouvelles publications IEC. Just
Published détaille les nouvelles publications parues. Si vous désirez nous donner des commentaires sur cette
Disponible en ligne et aussi une fois par mois par email. publication ou si vous avez des questions contactez-nous:
[e-mail].
IEC 61760-4 ®
Edition 1.0 2015-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Surface mounting technology –
Part 4: Classification, packaging, labelling and handling of moisture sensitive

devices
Technique du montage en surface (SMT) –

Partie 4: Classification, emballage, étiquetage et manipulation des dispositifs

sensibles à l'humidité
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.190 ISBN 978-2-8322-2666-7

– 2 – IEC 61760-4:2015 © IEC 2015
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 General information . 9
4.1 Moisture sensitive devices . 9
4.2 Moisture sensitivity level (MSL) . 10
4.3 Relation to other environmental test methods (humidity tests) . 10
5 Assessment of moisture sensitivity . 10
5.1 Identification of non moisture sensitive devices . 10
5.2 Classification . 10
6 Test procedure . 11
6.1 General . 11
6.1.1 Structurally similar components . 11
6.1.2 Verification and validation tests . 11
6.1.3 Selection of applicable soak conditions and temperature profile . 12
6.2 Drying . 12
6.3 Moisture soak . 12
6.4 Temperature load . 13
6.4.1 Classification temperature profile . 13
6.4.2 Classification temperature profile for special devices . 14
6.5 Recovery . 14
6.6 Final measurements . 14
6.6.1 Requirements . 14
6.6.2 Visual inspection . 15
6.6.3 Electrical measurements . 15
6.6.4 Non-destructive inspection (if required) . 15
6.7 Classification . 15
6.8 Information to be given in the relevant specification . 15
7 Requirements to packaging and labelling . 16
7.1 Packaging process . 16
7.1.1 Drying of MSDs and carrier materials before being sealed in MBBs . 16
7.1.2 Evacuation and sealing . 17
7.2 Packaging material for dry pack . 17
7.2.1 Moisture barrier bag (MBB) . 17
7.2.2 Desiccant . 17
7.2.3 Humidity indicator . 19
7.3 Information to be given on labels . 20
8 Handling of moisture sensitive devices . 21
8.1 Storage . 21
8.1.1 Recommended storage conditions . 21
8.1.2 Shelf life . 21
8.1.3 Floor life . 21
8.2 ESD . 22

8.3 Humidity indication . 22
8.3.1 Humidity indicator card (HIC) . 22
8.3.2 Moisture indicating desiccant . 22
8.4 Unpacking and re-packing . 22
9 Drying. 23
9.1 Drying options . 23
9.2 Methods . 24
9.2.1 General considerations for baking . 24
9.2.2 Bakeout times . 24
9.2.3 ESD protection . 25
9.2.4 Reuse of carriers . 25
9.2.5 Solderability limitations . 25
Annex A (informative) Moisture sensitivity of assemblies . 26
Annex B (informative) Mass/gain loss analysis . 27
Annex C (informative) Baking of devices . 28
C.1 Baking time and conditions . 28
C.2 Example of a baking process . 28
Annex D (normative) Moisture sensitivity labels . 30
D.1 Object . 30
D.2 Graphical symbols and labels . 30
D.2.1 Graphical symbol for moisture-sensitivity . 30
D.2.2 Moisture-sensitivity identification label (MSID) . 30
D.2.3 Moisture-sensitivity caution label (MSCL) . 31
Bibliography . 32

Figure 1 – Classification temperature profile . 13
Figure 2 – Examples of humidity indicator cards . 20
Figure C.1 – Baking process . 29
Figure D.1 – Standardized graphical symbol for use on equipment . 30
Figure D.2 – Alternative moisture sensitivity symbol (also in market use) . 30
Figure D.3 – MSID labels (examples) . 31

Table 1 – Moisture sensitivity levels . 11
Table 2 – Moisture soak conditions . 12
Table 3 – Parameters of the classification temperature profile . 14
Table 4 – Classification temperatures T . 14
c
Table 5 – MBB material properties . 17
Table 6 – Conditions for re-bake – Example for one type of plastic encapsulated
devices . 23
Table 7 – Conditions for baking prior to dry pack – Example for one type of plastic
encapsulated devices . 24

– 4 – IEC 61760-4:2015 © IEC 2015
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SURFACE MOUNTING TECHNOLOGY –
Part 4: Classification, packaging,
labelling and handling of moisture sensitive 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
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 61760-4 has been prepared by IEC technical committee 91:
Electronics assembly technology.
The text of this standard is based on the following documents:
FDIS Report on voting
91/1244FDIS 91/1259/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.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 61760, published under the general title Surface mounting
technology, 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 website 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.
IMPORTANT – The 'colour inside' logo on the cover page of this publication 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 61760-4:2015 © IEC 2015
INTRODUCTION
Due to the higher temperature profiles of reflow soldering processes using tin-silver-copper
alloys or other lead-free solder alloys with higher melting temperatures than Sn-Pb eutectic
solder, the sensitivity of components against soldering heat, when being exposed to moisture
before soldering, becomes an increasingly important factor.
The currently existing standards describing the moisture sensitivity classification of devices
are applicable for plastic encapsulated semiconductors and similar solid state packages (e.g.
IEC 60749-20), but not for other types of components.
This part of IEC 61760 also extends the classification and packaging methods as described in
J-STD-020 and J-STD-033. It is intended to be used for such type of components, where
J-STD-020 and J-STD-033 are not required or not appropriate.

SURFACE MOUNTING TECHNOLOGY –
Part 4: Classification, packaging,
labelling and handling of moisture sensitive devices

1 Scope
This part of IEC 61760 specifies the classification of moisture sensitive devices into moisture
sensitivity levels related to soldering heat, and provisions for packaging, labelling and
handling.
This part of IEC 61760 extends the classification and packaging methods to such components,
where currently existing standards are not required or not appropriate. For such cases this
standard introduces additional moisture sensitivity levels and an alternative method for
packaging.
This standard applies to devices intended for reflow soldering, like surface mount devices,
including specific through-hole devices (where the device supplier has specifically
documented support for reflow soldering), but not to
• semiconductor devices,
• devices for flow (wave) soldering.
NOTE Background of this standard and its relation to currently existing standards, e.g. IEC 60749-20 or J-STD-
020 and J-STD-033, are described in the INTRODUCTION.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60068-1, Environmental testing – Part 1: General and guidance
IEC 60749-20, Semiconductor devices – Mechanical and climatic test methods – Part 20:
Resistance of plastic encapsulated SMDs to the combined effect of moisture and soldering
heat
IEC 61340-5-1, Electrostatics – Part 5-1: Protection of electronic devices from electrostatic
phenomena – General requirements
IEC 61760-2, Surface mounting technology – Part 2: Transportation and storage conditions
of surface mounting devices (SMD) – Application guide
IPC/JEDEC J-STD-020D.1, March 2008, Moisture/Reflow Sensitivity Classification for Non-
hermetic Solid State Surface Mount Devices
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

– 8 – IEC 61760-4:2015 © IEC 2015
3.1
moisture sensitive device
MSD
device, where during soldering the evaporation of absorbed moisture is likely to deteriorate its
electrical or mechanical performance compared to what is given in the relevant specification
Note 1 to entry: This note applies to the French language only.
3.2
moisture sensitivity level
MSL
rating indicating a device’s susceptibility to damage due to absorbed moisture when subjected
to reflow soldering
Note 1 to entry: This note applies to the French language only.
3.3
moisture barrier bag
MBB
bag designed to restrict the transmission of water vapour and used to pack moisture sensitive
devices
Note 1 to entry: This note applies to the French language only.
3.4
manufacturer’s exposure time
MET
maximum time after baking that the component manufacturer requires to process components
prior to sealing of the bag
Note 1 to entry: The manufacturer’s exposure time also includes the maximum time allowed at the distributor in
order to keep the bag open to split up its content into smaller shipments.
Note 2 to entry: This note applies to the French language only.
3.5
floor life
allowable time for a device or semi-finished assembly to be exposed to normal room
environment humidity and temperature after removal from a moisture barrier bag or storage
chamber and before a solder reflow process
3.6
shelf life
recommendation of time that products can be stored in the original packaging, during which
the defined quality of the goods remains acceptable under specified conditions of
transportation, storage and handling
3.7
active desiccant
absorbent material used to maintain a low relative humidity
3.8
unit of desiccant
amount of active desiccant that will absorb a minimum of 2,85 g of water vapour at 25 °C and
a relative humidity of 20 % within 24 h
3.9
moisture indicating desiccant
desiccant whose colour (hue) changes perceptibly, when a certain relative humidity is
exceeded
Note 1 to entry: Typically a colour change due to a moisture indicating desiccant is from blue to pink, when the
change from dry state to wet state is detected.
3.10
humidity indicator card
HIC
card on which a moisture sensitive chemical is printed such that it changes colour from dry to
wet when the indicated relative humidity is exceeded
Note 1 to entry: This note applies to the French language only.
3.11
water vapour transmission rate
WVTR
measure of the permeability of a plastic film material to moisture, used to specify a moisture
barrier bag for dry packing
Note 1 to entry: This note applies to the French language only.
4 General information
4.1 Moisture sensitive devices
Certain materials, plastic polymers and fillers are hygroscopic and can absorb moisture
dependent on time and the storage environment. Absorbed moisture will vaporize during rapid
heating in the solder reflow process, generating
• pressure in the material,
• deformation,
• swelling,
• delamination,
• cracking,
• degradation of inner connection.
The penetration of moisture into the absorbing material is generally caused through exposure
to the ambient air. Moisture absorption or moisture penetrating into cavities can lead to
moisture concentrations in the device which are high enough to cause cracking and/or
delamination to the device during the soldering process (e.g. “popcorn phenomenon”), which
may adversely affect reliability.
NOTE “Popcorn phenomenon”: internal stress causes the package to bulge and then crack with an audible “pop”.
Moisture can also influence the bonding strength of adhesives, sealings, encapsulants,
plastics with galvanic coating, etc.
Moisture exposure also can induce the transport of ionic contaminations into the device,
thereby increasing the potential for circuit failure due to corrosion.
Hence it is necessary to dry moisture-sensitive devices, to seal them in a moisture barrier bag
and only to remove them immediately prior to soldering onto the PCB. The permissible time
from the opening of the moisture barrier bag until the final soldering process that a device can
remain unprotected in an environment with a level of humidity approximating to real-world
conditions (e.g. 30 °C/60 % RH) is a measure of the sensitivity of the device to ambient
humidity. This amount of time is called floor life.

– 10 – IEC 61760-4:2015 © IEC 2015
4.2 Moisture sensitivity level (MSL)
The moisture sensitivity level (MSL) is determined at the classification temperature, which is
set above practical soldering temperatures. The actual soldering temperature measured at the
top surface of the component therefore shall be less than the classification temperature.
Packaging, storage, floor life and pre-treatment of moisture sensitive devices before being
subjected to reflow soldering processes are identified by the MSL (see Clause 5 and Table 1).
The method for classification of devices into MSL is described in Clause 6.
4.3 Relation to other environmental test methods (humidity tests)
In humidity tests, e.g. as in IEC 60068-2-78, devices are tested as they are (unmounted) or in
mounted condition, e.g. soldered to a test board. These tests detect the influence of adsorbed
or absorbed moisture to the performance of the device, e.g. electrical characteristics,
corrosion effects, but cannot detect the influence of absorbed moisture to the sensitivity
against heat stresses of the soldering processes.
The target of the test method described in this standard is to test the resistance of devices
against the soldering heat in combination with the humidity load as preconditioning process.
Other effects of humidity, like detoriation of electrical characteristics or isolation properties,
are not covered by this standard and need to be tested separately.
5 Assessment of moisture sensitivity
5.1 Identification of non moisture sensitive devices
Non moisture sensitive devices shall be identified by analysis of design and materials of
devices depending on whether they can absorb humidity, or humidity can penetrate into
cavities. If the materials apparently do not absorb humidity, the devices may be declared by
the manufacturer as non moisture sensitive.
Such non moisture sensitive devices shall be designated as level “N”. There are no
requirements for non moisture sensitive devices.
5.2 Classification
The procedure to classify moisture sensitive devices into MSL is described in Clause 6. The
devices are classified at the appropriate classification temperature selected from Table 3 and
Table 4.
The recommended procedure is to start testing at the lowest moisture sensitivity level, which
the evaluation package is reasonably expected to pass (based on knowledge of other similar
evaluation packages).
If supplier and user agree, components can be classified at temperatures other than those in
Table 4.
If the conditions in Table 1 and/or Table 2 are not suitable for a specific product, other
conditions can be applied according to the agreement between users and suppliers.

Table 1 – Moisture sensitivity levels
LEVEL Floor life Floor life Shelf life Protective packaging Desic- Humidity
time condition cant indicator
(reference
condition)
a
1 No requirement
≤30 °C/85 % RH
b
MBB type 1 ,
a c
2 1 year ≤30 °C/60 % RH <60 % RH in MBB No Optional
no pre-drying
b
MBB type 1 ,
C2a <30 % RH in MBB
no pre-drying
c
b
4 weeks ≤30 °C/60 % RH Yes Yes
MBB type 2 ,
2a
<10 % RH in MBB
pre-drying
b
MBB type 1 ,
12 months
or as
C3 <30 % RH in MBB
specified
by the
no pre-drying
c
168 h supplier
≤30 °C/60 % RH Yes Yes
b
MBB type 2 ,
3 <10 % RH in MBB
pre-drying
b
MBB type 2 ,
c
4 72 h ≤30 °C/60 % RH <10 % RH in MBB Yes Yes
pre-drying
b
MBB type 2 ,
c
5 48 h ≤30 °C/60 % RH Yes Yes
<10 % RH in MBB
pre-drying
The floor life can be longer if the environmental conditions are less severe than the reference condition, or
shorter, if more severe.
Extended shelf life can be agreed upon, but needs recalculation of the amount of desiccant.
a
The sum of keeping time at floor and storage time should not exceed the maximum storage period as
specified by the supplier.
b
The required shelf life and humidity in packed condition shall be assured by the amount of the desiccant,
calculated by the use of WVTR (water vapour transmission rate) of the applied MBB. For the description of
MBB type, see Table 5.
c
Humidity indicator can be HIC or moisture indicating desiccant.

6 Test procedure
6.1 General
6.1.1 Structurally similar components
Classification may be performed for a group of structurally similar components. Information
about structural similarity shall be given in the relevant specification.
6.1.2 Verification and validation tests
The relevant specification shall describe the minimum number of specimens to be tested. The
minimum number should be at least 11 pieces.

– 12 – IEC 61760-4:2015 © IEC 2015
NOTE A sample of 11 pieces tested with an acceptance number zero represents a Lot Tolerance Percent
Defective (LTPD) of 20 % with a confidence level (C.L.) of 90 %. See ISO 2859-1 for further information.
6.1.3 Selection of applicable soak conditions and temperature profile
The soak conditions related to the MSL shall be selected from Table 2, the applicable
temperature profile for classification (Figure 1) from Table 3 and Table 4.
6.2 Drying
Unless otherwise specified in the relevant specification, the specimen shall be baked at
125 °C ± 5 °C for at least 24 h.
However, alternative baking conditions can be applied, when confirmed by the mass gain or
loss analysis as described in Annex B.
6.3 Moisture soak
Table 2 – Moisture soak conditions
a
LEVEL Soak time Soak condition Alternative
h
1 (168 +5/-0) (85 ± 2) °C, (85 ± 5) % RH (336 +5/-0) h; (85 ± 2) °C, (60 ± 5) % RH
2 (168 +5/-0) (85 ± 2) °C, (60 ± 5) % RH –
(168 +5/-0) (85 ± 2) °C, (30 ± 5) % RH,
C2a followed by followed by
(672 +5/-0) (30 ± 2) °C, (60 ± 5) % RH
2a (696 + 5/-0) (30 ± 2) °C, (60 ± 5) % RH
(168 +5/-0) (85 ± 2) °C, (30 ± 5) % RH,
–
C3 followed by followed by
(168 +5/-0) (30 ± 2) °C, (60 ± 5) % RH
(192 +5/-0) (30 ± 2) °C, (60 ± 5) % RH
4 (96 +2/-0)
(30 ± 2) °C, (60 ± 5) % RH
5 (72 +2/-0)
In levels C2a and C3, the first stage of soak condition corresponds to shelf life (≤30 °C, ≤30 % RH, 1 year) in

the MBB type 1. The second stage of soak condition corresponds to floor life (see IEC 60749-20).
a
Soak conditions according to IPC/JEDEC J-STD-020D.1. Alternatively accelerated equivalent soak
conditions from Table 5-1 in J-STD-020D.1:2008 may be applied in case the activation energy is confirmed
by the manufacturer.
6.4 Temperature load
6.4.1 Classification temperature profile
t
T
c
T – 5 °C
c
T
T
c
t
b
T
t
a
t
Time
IEC
Key
T Minimum preheating temperature
T Maximum preheating temperature
T Liquidus temperature
T Classification temperature
c
t Preheating duration
t Time at liquidus
t Time within (T – 5 °C)
3 c
t Time to T
4 c
a The temperature gradient of the increasing slope shall not exceed 3 K/s.
b Preheat area.
c The temperature gradient of the decreasing slope shall not exceed 6 K/s.
Figure 1 – Classification temperature profile
Temperature
– 14 – IEC 61760-4:2015 © IEC 2015
Table 3 – Parameters of the classification temperature profile
Solder Sn-Pb SnAgCu
process (or equivalent) (or equivalent)
T 100 °C 150 °C
T
150 °C 200 °C
t (60 to 120) s (60 to 120) s
T 183 °C 217 °C
t (60 to 150) s (60 to 150) s
t 20 s 30 s
T See Table 4
c
t ≤6 min ≤8 min
Table 4 – Classification temperatures T
c
Classification temperature T for package volume
c
Solder process Package thickness
3 3
350 mm to
<350 mm >2 000 mm
2 000 mm
mm °C °C °C
SnPb
<2,5 235 220 220
or equivalent
≥2,5 220 220 220
SnAgCu
<1,6 260 260 260
or equivalent
1,6 to 2,5 260 250 245
>2,5 250 245 245
>2,5
b b
plus high thermal not applicable 230 230
a
capacity
a
This condition may be applied for devices with high thermal mass, where peak package temperature does
not reach 245 °C when soldered with a profile typical to soldering processes using SnAgCu alloy solder, or
for very temperature sensitive devices. The peak package temperature is measured at the device surface or
any other point specified in the relevant specification.
b
Τ measured at the device terminal or solder joint shall achieve the minimum temperature and time needed
c
for a specific solder alloy to form a solder joint.

6.4.2 Classification temperature profile for special devices
When the classification temperature profiles of Table 3 and Table 4 are not applicable to a
device (e.g. components with high thermal mass and/or thermal sensitivity), other profiles may
be specified in the relevant specification according to the agreement between user and
supplier. For reference see also IEC 60068-2-58:2004, Table 7.
6.5 Recovery
The specimen shall be stored under the standard atmospheric conditions for measurements
and test as given in IEC 60068-1, (15 to 35) °C, (25 to 75) % RH for the time given in the
relevant specification.
6.6 Final measurements
6.6.1 Requirements
A component is considered to pass that level of moisture sensitivity if it passes the
requirements of 6.6.2 and 6.6.3, and if required, the non-destructive inspection of 6.6.4.

6.6.2 Visual inspection
Visual inspection shall be performed after the test. Special attention shall be paid to external
cracks and swelling which will be looked for under a magnification of 40×.
A device shall be considered as failure if it exhibits any of the following:
a) external crack visible using 40× optical microscope;
b) internal crack or delamination that intersects internal connections;
c) internal crack or delamination extending from any terminal to any other internal element
relevant for the function of the device;
d) internal crack or delamination extending more than 2/3 the distance from any internal
element relevant for the function of the device to the outside of the package;
e) changes in package body flatness caused by warpage, swelling or bulging invisible to the
naked eye;
f) dimensions out of specification.
Hot temperature warpage may be specified for multi-pin devices. If parts meet in hot condition
co-planarity and standoff dimensions as specified at room temperature, they shall be
considered passing.
The relevant specification may prescribe additional inspection criteria.
If internal cracks are detected by non-destructive inspection in 6.6.4, they are considered a
failure or verified good using polished cross sections through the identified site.
For packages known to be sensitive to vertical cracks, it is recommended that polished cross
sections be used to confirm the nonexistence of near vertical cracks within the mould
compound or encapsulant.
6.6.3 Electrical measurements
Electrical measurements on all devices shall be performed as required by the relevant
specification, e.g. datasheet, detail specifications, etc.
6.6.4 Non-destructive inspection (if required)
If required by the relevant specification, non-destructive inspection (e.g. x-ray computed
tomography, scanning acoustic microscopy, etc.) shall be performed.
6.7 Classification
If one or more devices in the test sample fail at final measurements, the package shall be
considered not to have passed the tested level.
If a device does not pass level 5, it is classified as extremely moisture sensitive and dry pack
will not provide adequate protection. If such devices are shipped, the customer shall be
advised of its classification. The supplier shall also include a warning label with the devices
indicating that those either shall be socket mounted, or baked dry within a time given on the
label before reflow soldering.
6.8 Information to be given in the relevant specification
The following details shall be specified in the relevant specification:
a) MSL and classification temperature profile;

– 16 – IEC 61760-4:2015 © IEC 2015
b) reject criteria, including non-destructive inspection criteria, in addition to those in 6.6.2
through 6.6.4;
c) any preconditioning requirements different to those given in 6.2 and 6.3.
7 Requirements to packaging and labelling
7.1 Packaging process
7.1.1 Drying of MSDs and carrier materials before being sealed in MBBs
7.1.1.1 Requirements – Levels 2, C2a and C3
Packing of the MSDs into MBBs shall be carried out under environmental conditions below
30 °C/60 % RH, within one week after moulding, burn-in, baking or other heating process.
MET is not specified.
MBBs may be opened for a short period of time, e.g less than 1 h, and re-closed provided, if
present, that the HIC indicates a humidity of less than 30 % RH and provided that the
desiccant is replaced with fresh desiccant. When the MBB is next opened, as long as the HIC
indicates below 30 % RH, the duration time of the previous MBB’s opening may be
disregarded. Thus, if the HIC indicates below 30 % RH when MBB is opened, the floor life is
not dependent on the duration time of MBBs opening.
7.1.1.2 Drying requirements – Levels 2a, 3, 4 or 5
MSDs classified as levels 2a, 3, 4, or 5 shall be dried according to Clause 9 prior to being
sealed in MBBs. The period between drying and sealing shall not exceed the MET less the
time allowed for distributors to open the bags and repack parts. If the supplier’s actual MET is
more than the default 24 h, then the actual time shall be used. If the distributor practice is to
repack the MBBs with active desiccant, then this time does not need to be subtracted from the
MET.
Heating processes such as moulding, burn-in or baking can be regarded as pre-drying. If the
MSDs are stored in the low humidity controlled conditions until packaging into MBBs, MET
can be extended.
7.1.1.3 Drying requirements – Carrier materials
The materials from which carriers such as trays, tubes, reels, etc. are made can affect the
desiccant capacity when placed in the MBB. Therefore, the effect of these materials shall be
compensated for by baking or, if required, adding additional desiccant in the MBB to ensure
the shelf life of the devices (see 8.1.2).
7.1.1.4 Drying requirements – Other
Suppliers may use the drying effect of normal in-line processes such as post mould cure,
marking cure, and burn-in to reduce the baking time. An equivalency evaluation is
recommended to ensure that high-temperature processing maintains moisture mass gain to an
acceptable level. The total mass gain for the device at the time it is sealed in the MBB shall
not exceed the moisture gain of that device starting dry and then being exposed to 30 °C and
60 % RH for MET less the time for distributors.
7.1.1.5 Excess time between baking and packing
If the allowable time between baking and packing is exceeded, the devices shall be re-dried in
accordance with 9.1.
7.1.2 Evacuation and se
...

IEC 61760-4 ®
Edition 1.1 2018-03
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Surface mounting technology –
Part 4: Classification, packaging, labelling and handling of moisture sensitive
devices
Technique du montage en surface (SMT) –
Partie 4: Classification, emballage, étiquetage et manipulation des dispositifs
sensibles à l'humidité
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.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: [phone]
3, rue de Varembé [e-mail]
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 corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 21 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - webstore.iec.ch/advsearchform IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 67 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: [e-mail].
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Catalogue IEC - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
Application autonome pour consulter tous les renseignements
Le premier dictionnaire en ligne de termes électroniques et
bibliographiques sur les Normes internationales,
électriques. Il contient 21 000 termes et définitions en anglais
Spécifications techniques, Rapports techniques et autres
et en français, ainsi que les termes équivalents dans 16
documents de l'IEC. Disponible pour PC, Mac OS, tablettes
langues additionnelles. Egalement appelé Vocabulaire
Android et iPad.
Electrotechnique International (IEV) en ligne.

Recherche de publications IEC -
Glossaire IEC - std.iec.ch/glossary
webstore.iec.ch/advsearchform
67 000 entrées terminologiques électrotechniques, en anglais
La recherche avancée permet de trouver des publications IEC et en français, extraites des articles Termes et Définitions des
en utilisant différents critères (numéro de référence, texte, publications IEC parues depuis 2002. Plus certaines entrées
comité d’études,…). Elle donne aussi des informations sur les antérieures extraites des publications des CE 37, 77, 86 et
projets et les publications remplacées ou retirées. CISPR de l'IEC.

IEC Just Published - webstore.iec.ch/justpublished Service Clients - webstore.iec.ch/csc
Restez informé sur les nouvelles publications IEC. Just Si vous désirez nous donner des commentaires sur cette
Published détaille les nouvelles publications parues. publication ou si vous avez des questions contactez-nous:
Disponible en ligne et aussi une fois par mois par email. [e-mail].

IEC 61760-4 ®
Edition 1.1 2018-03
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Surface mounting technology –
Part 4: Classification, packaging, labelling and handling of moisture sensitive

devices
Technique du montage en surface (SMT) –

Partie 4: Classification, emballage, étiquetage et manipulation des dispositifs

sensibles à l'humidité
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.190 ISBN 978-2-8322-5481-3

IEC 61760-4 ®
Edition 1.1 2018-03
CONSOLIDATED VERSION
REDLINE VERSION
VERSION REDLINE
colour
inside
Surface mounting technology –
Part 4: Classification, packaging, labelling and handling of moisture sensitive
devices
Technique du montage en surface (SMT) –
Partie 4: Classification, emballage, étiquetage et manipulation des dispositifs
sensibles à l'humidité
– 2 – IEC 61760-4:2015+AMD1:2018 CSV
© IEC 2018
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 General information . 9
4.1 Moisture sensitive devices . 9
4.2 Moisture sensitivity level (MSL) . 10
4.3 Relation to other environmental test methods (humidity tests) . 10
5 Assessment of moisture sensitivity . 10
5.1 Identification of non moisture sensitive devices . 10
5.2 Classification . 10
6 Test procedure . 11
6.1 General . 11
6.1.1 Structurally similar components . 11
6.1.2 Verification and validation tests . 11
6.1.3 Selection of applicable soak conditions and temperature profile . 12
6.2 Drying . 12
6.3 Moisture soak . 12
6.4 Temperature load . 13
6.4.1 Classification temperature profile . 13
6.4.2 Classification temperature profile for special devices . 14
6.4.3 Reflow . 14
6.5 Recovery . 15
6.6 Final measurements . 15
6.6.1 Requirements . 15
6.6.2 Visual inspection . 15
6.6.3 Electrical measurements . 16
6.6.4 Non-destructive inspection (if required) . 16
6.7 Classification . 16
6.8 Information to be given in the relevant specification . 16
7 Requirements to packaging and labelling . 16
7.1 Packaging process . 16
7.1.1 Drying of MSDs and carrier materials before being sealed in MBBs . 16
7.1.2 Evacuation and sealing . 17
7.2 Packaging material for dry pack . 17
7.2.1 Moisture barrier bag (MBB) . 17
7.2.2 Desiccant . 18
7.2.3 Humidity indicator . 20
7.3 Information to be given on labels . 21
8 Handling of moisture sensitive devices . 21
8.1 Storage . 21
8.1.1 Recommended storage conditions . 21
8.1.2 Shelf life . 22
8.1.3 Floor life . 22

© IEC 2018
8.2 ESD . 22
8.3 Humidity indication . 22
8.3.1 Humidity indicator card (HIC) . 22
8.3.2 Moisture indicating desiccant . 23
8.4 Unpacking and re-packing . 23
9 Drying. 23
9.1 Drying options . 23
9.2 Methods . 25
9.2.1 General considerations for baking . 25
9.2.2 Bakeout times . 25
9.2.3 ESD protection . 25
9.2.4 Reuse of carriers . 25
9.2.5 Solderability limitations . 25
Annex A (informative) Moisture sensitivity of assemblies . 26
Annex B (informative) Mass/gain loss analysis . 27
Annex C (informative) Baking of devices . 28
C.1 Baking time and conditions . 28
C.2 Example of a baking process . 28
Annex D (normative) Moisture sensitivity labels . 30
D.1 Object . 30
D.2 Graphical symbols and labels . 30
D.2.1 Graphical symbol for moisture-sensitivity . 30
D.2.2 Moisture-sensitivity identification label (MSID) . 30
D.2.3 Moisture-sensitivity caution label (MSCL) . 31
Bibliography . 32

Figure 1 – Classification temperature profile . 13
Figure 2 – Examples of humidity indicator cards . 20
Figure C.1 – Baking process . 29
Figure D.1 – Standardized graphical symbol for use on equipment . 30
Figure D.2 – Alternative moisture sensitivity symbol (also in market use) . 30
Figure D.3 – MSID labels (examples) . 31

Table 1 – Moisture sensitivity levels . 11
Table 2 – Moisture soak conditions . 12
Table 3 – Parameters of the classification temperature profile . 14
Table 4 – Classification temperatures T . 14
c
Table 5 – MBB material properties . 18
Table 6 – Conditions for re-bake – Example for one type of plastic encapsulated
devices . 23
Table 7 – Conditions for baking prior to dry pack – Example for one type of plastic
encapsulated devices . 24

– 4 – IEC 61760-4:2015+AMD1:2018 CSV
© IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SURFACE MOUNTING TECHNOLOGY –
Part 4: Classification, packaging,
labelling and handling of moisture sensitive 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
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.
This consolidated version of the official IEC Standard and its amendment has been prepared
for user convenience.
IEC 61760-4 edition 1.1 contains the first edition (2015-05) [documents 91/1244FDIS and
91/1259/RVD] and its amendment 1 (2018-03) [documents 91/1419/CDV and 91/1486/RVC].
In this Redline version, a vertical line in the margin shows where the technical content is
modified by amendment 1. Additions are in green text, deletions are in strikethrough red text.
A separate Final version with all changes accepted is available in this publication.

© IEC 2018
International Standard IEC 61760-4 has been prepared by IEC technical committee 91:
Electronics assembly technology.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 61760, published under the general title Surface mounting
technology, can be found on the IEC website.
The committee has decided that the contents of the base publication and its amendment 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.
IMPORTANT – The 'colour inside' logo on the cover page of this publication 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 61760-4:2015+AMD1:2018 CSV
© IEC 2018
INTRODUCTION
Due to the higher temperature profiles of reflow soldering processes using tin-silver-copper
alloys or other lead-free solder alloys with higher melting temperatures than Sn-Pb eutectic
solder, the sensitivity of components against soldering heat, when being exposed to moisture
before soldering, becomes an increasingly important factor.
The currently existing standards describing the moisture sensitivity classification of devices
are applicable for plastic encapsulated semiconductors and similar solid state packages (e.g.
IEC 60749-20), but not for other types of components.
This part of IEC 61760 also extends the classification and packaging methods as described in
J-STD-020 and J-STD-033. It is intended to be used for such type of components, where
J-STD-020 and J-STD-033 are not required or not appropriate.
It is important to note that moisture sensitivity levels existing in both J-STD 020 and
IEC 61760-4 are equivalent.
© IEC 2018
SURFACE MOUNTING TECHNOLOGY –
Part 4: Classification, packaging,
labelling and handling of moisture sensitive devices

1 Scope
This part of IEC 61760 specifies the classification of moisture sensitive devices into moisture
sensitivity levels related to soldering heat, and provisions for packaging, labelling and
handling.
This part of IEC 61760 extends the classification and packaging methods to such components,
where currently existing standards are not required or not appropriate. For such cases this
standard introduces additional moisture sensitivity levels and an alternative method for
packaging.
This standard applies to devices intended for reflow soldering, like surface mount devices,
including specific through-hole devices (where the device supplier has specifically
documented support for reflow soldering), but not to
• semiconductor devices,
• devices for flow (wave) soldering.
NOTE Background of this standard and its relation to currently existing standards, e.g. IEC 60749-20 or J-STD-
020 and J-STD-033, are described in the INTRODUCTION.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60068-1, Environmental testing – Part 1: General and guidance
IEC 60749-20, Semiconductor devices – Mechanical and climatic test methods – Part 20:
Resistance of plastic encapsulated SMDs to the combined effect of moisture and soldering
heat
IEC 61340-5-1, Electrostatics – Part 5-1: Protection of electronic devices from electrostatic
phenomena – General requirements
IEC 61760-2, Surface mounting technology – Part 2: Transportation and storage conditions
of surface mounting devices (SMD) – Application guide
IPC/JEDEC J-STD-020D.1, March 2008, Moisture/Reflow Sensitivity Classification for Non-
hermetic Solid State Surface Mount Devices
IPC/JEDEC J-STD-020E, January 2015, Moisture/Reflow Sensitivity Classification for
Nonhermetic Solid State Surface Mount Devices

– 8 – IEC 61760-4:2015+AMD1:2018 CSV
© IEC 2018
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
moisture sensitive device
MSD
device, where during soldering the evaporation of absorbed moisture is likely to deteriorate its
electrical or mechanical performance compared to what is given in the relevant specification
Note 1 to entry: This note applies to the French language only.
3.2
moisture sensitivity level
MSL
rating indicating a device’s susceptibility to damage due to absorbed moisture when subjected
to reflow soldering
Note 1 to entry: This note applies to the French language only.
3.3
moisture barrier bag
MBB
bag designed to restrict the transmission of water vapour and used to pack moisture sensitive
devices
Note 1 to entry: This note applies to the French language only.
3.4
manufacturer’s exposure time
MET
maximum time after baking that the component manufacturer requires to process components
prior to sealing of the bag
Note 1 to entry: The manufacturer’s exposure time also includes the maximum time allowed at the distributor in
order to keep the bag open to split up its content into smaller shipments.
Note 2 to entry: This note applies to the French language only.
3.5
floor life
allowable time for a device or semi-finished assembly to be exposed to normal room
environment humidity and temperature after removal from a moisture barrier bag or storage
chamber and before a solder reflow process
3.6
shelf life
recommendation of time that products can be stored in the original packaging, during which
the defined quality of the goods remains acceptable under specified conditions of
transportation, storage and handling
3.7
active desiccant
absorbent material used to maintain a low relative humidity
3.8
unit of desiccant
amount of active desiccant that will absorb a minimum of 2,85 g of water vapour at 25 °C and
a relative humidity of 20 % within 24 h

© IEC 2018
3.9
moisture indicating desiccant
desiccant whose colour (hue) changes perceptibly, when a certain relative humidity is
exceeded
Note 1 to entry: Typically a colour change due to a moisture indicating desiccant is from blue to pink, when the
change from dry state to wet state is detected.
3.10
humidity indicator card
HIC
card on which a moisture sensitive chemical is printed such that it changes colour from dry to
wet when the indicated relative humidity is exceeded
Note 1 to entry: This note applies to the French language only.
3.11
water vapour transmission rate
WVTR
measure of the permeability of a plastic film material to moisture, used to specify a moisture
barrier bag for dry packing
Note 1 to entry: This note applies to the French language only.
4 General information
4.1 Moisture sensitive devices
Certain materials, plastic polymers and fillers are hygroscopic and can absorb moisture
dependent on time and the storage environment. Absorbed moisture will vaporize during rapid
heating in the solder reflow process, generating
• pressure in the material,
• deformation,
• swelling,
• delamination,
• cracking,
• degradation of inner connection.
The penetration of moisture into the absorbing material is generally caused through exposure
to the ambient air. Moisture absorption or moisture penetrating into cavities can lead to
moisture concentrations in the device which are high enough to cause cracking and/or
delamination to the device during the soldering process (e.g. “popcorn phenomenon”), which
may adversely affect reliability.
NOTE “Popcorn phenomenon”: internal stress causes the package to bulge and then crack with an audible “pop”.
Moisture can also influence the bonding strength of adhesives, sealings, encapsulants,
plastics with galvanic coating, etc.
Moisture exposure also can induce the transport of ionic contaminations into the device,
thereby increasing the potential for circuit failure due to corrosion.
Hence it is necessary to dry moisture-sensitive devices, to seal them in a moisture barrier bag
and only to remove them immediately prior to soldering onto the PCB. The permissible time
from the opening of the moisture barrier bag until the final soldering process that a device can
remain unprotected in an environment with a level of humidity approximating to real-world

– 10 – IEC 61760-4:2015+AMD1:2018 CSV
© IEC 2018
conditions (e.g. 30 °C/60 % RH) is a measure of the sensitivity of the device to ambient
humidity. This amount of time is called floor life.
4.2 Moisture sensitivity level (MSL)
The moisture sensitivity level (MSL) is determined at the classification temperature, which is
set above practical soldering temperatures. The actual soldering temperature measured at the
top surface of the component therefore shall be less than the classification temperature.
Packaging, storage, floor life and pre-treatment of moisture sensitive devices before being
subjected to reflow soldering processes are identified by the MSL (see Clause 5 and Table 1).
The method for classification of devices into MSL is described in Clause 6.
4.3 Relation to other environmental test methods (humidity tests)
In humidity tests, e.g. as in IEC 60068-2-78, devices are tested as they are (unmounted) or in
mounted condition, e.g. soldered to a test board. These tests detect the influence of adsorbed
or absorbed moisture to the performance of the device, e.g. electrical characteristics,
corrosion effects, but cannot detect the influence of absorbed moisture to the sensitivity
against heat stresses of the soldering processes.
The target of the test method described in this standard is to test the resistance of devices
against the soldering heat in combination with the humidity load as preconditioning process.
Other effects of humidity, like detoriation of electrical characteristics or isolation properties,
are not covered by this standard and need to be tested separately.
5 Assessment of moisture sensitivity
5.1 Identification of non moisture sensitive devices
Non moisture sensitive devices shall be identified by analysis of design and materials of
devices depending on whether they can absorb humidity, or humidity can penetrate into
cavities. If the materials apparently do not absorb humidity, the devices may be declared by
the manufacturer as non moisture sensitive.
Such non moisture sensitive devices shall be designated as level “N”. There are no
requirements for non moisture sensitive devices.
5.2 Classification
The procedure to classify moisture sensitive devices into MSL is described in Clause 6. The
devices are classified at the appropriate classification temperature selected from Table 3 and
Table 4.
The recommended procedure is to start testing at the lowest moisture sensitivity level, which
the evaluation package is reasonably expected to pass (based on knowledge of other similar
evaluation packages).
If supplier and user agree, components can be classified at temperatures other than those in
Table 4.
If the conditions in Table 1 and/or Table 2 are not suitable for a specific product, other
conditions can be applied according to the agreement between users and suppliers.

© IEC 2018
Table 1 – Moisture sensitivity levels
LEVEL Floor life Floor life Shelf life Protective packaging Desic- Humidity
time condition cant indicator
(reference
condition)
a
1 No requirement
≤30 °C/85 % RH
b
MBB type 1 ,
a c
2 1 year ≤30 °C/60 % RH <60 % RH in MBB No Optional
no pre-drying
b
MBB type 1 ,
C2a <30 % RH in MBB
no pre-drying
c
b
4 weeks ≤30 °C/60 % RH Yes Yes
MBB type 2 ,
2a
<10 % RH in MBB
pre-drying
b
MBB type 1 ,
12 months
or as
C3 <30 % RH in MBB
specified
by the
no pre-drying
c
168 h supplier
≤30 °C/60 % RH Yes Yes
b
MBB type 2 ,
3 <10 % RH in MBB
pre-drying
b
MBB type 2 ,
c
4 72 h ≤30 °C/60 % RH <10 % RH in MBB Yes Yes
pre-drying
b
MBB type 2 ,
c
5 48 h ≤30 °C/60 % RH Yes Yes
<10 % RH in MBB
pre-drying
The floor life can be longer if the environmental conditions are less severe than the reference condition, or
shorter, if more severe.
Extended shelf life can be agreed upon, but needs recalculation of the amount of desiccant.
a
The sum of keeping time at floor and storage time should not exceed the maximum storage period as
specified by the supplier.
b
The required shelf life and humidity in packed condition shall be assured by the amount of the desiccant,
calculated by the use of WVTR (water vapour transmission rate) of the applied MBB. For the description of
MBB type, see Table 5.
c
Humidity indicator can be HIC or moisture indicating desiccant.

6 Test procedure
6.1 General
6.1.1 Structurally similar components
Classification may be performed for a group of structurally similar components. Information
about structural similarity shall be given in the relevant specification.
6.1.2 Verification and validation tests
The relevant specification shall describe the minimum number of specimens to be tested. The
minimum number should be at least 11 pieces.

– 12 – IEC 61760-4:2015+AMD1:2018 CSV
© IEC 2018
NOTE A sample of 11 pieces tested with an acceptance number zero represents a Lot Tolerance Percent
Defective (LTPD) of 20 % with a confidence level (C.L.) of 90 %. See ISO 2859-1 for further information.
6.1.3 Selection of applicable soak conditions and temperature profile
The soak conditions related to the MSL shall be selected from Table 2, the applicable
temperature profile for classification (Figure 1) from Table 3 and Table 4.
6.2 Drying
Unless otherwise specified in the relevant specification, the specimen shall be baked at
125 °C ± 5 °C for at least 24 h.
However, alternative baking conditions can be applied, when confirmed by the mass gain or
loss analysis as described in Annex B.
6.3 Moisture soak
Table 2 – Moisture soak conditions
a
LEVEL Soak time Soak condition Alternative
h
1 (168 +5/-0) (85 ± 2) °C, (85 ± 5) % RH (336 +5/-0) h; (85 ± 2) °C, (60 ± 5) % RH
2 (168 +5/-0) (85 ± 2) °C, (60 ± 5) % RH –
(168 +5/-0) (85 ± 2) °C, (30 ± 5) % RH,
C2a followed by followed by
(672 +5/-0) (30 ± 2) °C, (60 ± 5) % RH
2a (696 + 5/-0) (30 ± 2) °C, (60 ± 5) % RH
(168 +5/-0) (85 ± 2) °C, (30 ± 5) % RH,
–
C3 followed by followed by
(168 +5/-0) (30 ± 2) °C, (60 ± 5) % RH
(192 +5/-0) (30 ± 2) °C, (60 ± 5) % RH
4 (96 +2/-0)
(30 ± 2) °C, (60 ± 5) % RH
5 (72 +2/-0)
In levels C2a and C3, the first stage of soak condition corresponds to shelf life (≤30 °C, ≤30 % RH, 1 year) in

the MBB type 1. The second stage of soak condition corresponds to floor life (see IEC 60749-20).
a
Soak conditions according to IPC/JEDEC J-STD-020D.1 J-STD-020E. Alternatively accelerated equivalent
soak conditions from Table 5-1 in J-STD-020D.1:2008 J-STD-020E may be applied in case the activation
energy is confirmed by the manufacturer.

© IEC 2018
6.4 Temperature load
6.4.1 Classification temperature profile
t
T
c
T – 5 °C
c
T
T
c
t
b
T
t
a
t
Time
IEC
Key
T Minimum preheating temperature
T Maximum preheating temperature
T Liquidus temperature
T Classification temperature
c
t Preheating duration
t Time at liquidus
t Time within (T – 5 °C)
3 c
t Time to T
4 c
a The temperature gradient of the increasing slope shall not exceed 3 K/s.
b Preheat area.
c The temperature gradient of the decreasing slope shall not exceed 6 K/s.
Figure 1 – Classification temperature profile
Temperature
– 14 – IEC 61760-4:2015+AMD1:2018 CSV
© IEC 2018
Table 3 – Parameters of the classification temperature profile
Solder Sn-Pb SnAgCu
process (or equivalent) (or equivalent)
T 100 °C 150 °C
T
150 °C 200 °C
t (60 to 120) s (60 to 120) s
T 183 °C 217 °C
t (60 to 150) s (60 to 150) s
t 20 s 30 s
T See Table 4
c
t ≤6 min ≤8 min
Table 4 – Classification temperatures T
c
Classification temperature T for package volume
c
Solder process Package thickness
3 3
350 mm to
<350 mm >2 000 mm
2 000 mm
mm °C °C °C
SnPb
<2,5 235 220 220
or equivalent
≥2,5 220 220 220
SnAgCu
<1,6 260 260 260
or equivalent
1,6 to 2,5 260 250 245
>2,5 250 245 245
>2,5
b b
plus high thermal not applicable 230 230
a
capacity
a
This condition may be applied for devices with high thermal mass, where peak package temperature does
not reach 245 °C when soldered with a profile typical to soldering processes using SnAgCu alloy solder, or
for very temperature sensitive devices. The peak package temperature is measured at the device surface or
any other point specified in the relevant specification.
b
Τ measured at the device terminal or solder joint shall achieve the minimum temperature and time needed
c
for a specific solder alloy to form a solder joint.

6.4.2 Classification temperature profile for special devices
When the classification temperature profiles of Table 3 and Table 4 are not applicable to a
device (e.g. components with high thermal mass and/or thermal sensitivity), the temperature
profiles in Table 7 of IEC 60068-2-58:2015 can be used. Other profiles may be specified in
the relevant specification according to the agreement between the user and the supplier. For
reference more information, see also IEC 60068-2-58:2004, Table 7 J-STD-075:2008.
6.4.3 Reflow
The sample shall be subjected to 3 cycles of the appropriate reflow conditions as defined in
Figure 1, Table 3 and Table 4, starting in a time interval between 15 min to 4 h after removal
from the temperature/humidity chamber. The recovery period between two successive cycles
shall be the time it takes until the temperature of the specimen drops below 50 °C.
If the timing between removal from the temperature/humidity chamber and initial reflow cannot
be met, the parts shall be rebaked and resoaked according to 6.2 and 6.3.

© IEC 2018
All temperatures refer to the centre of the package, measured on the package body surface
that is facing upwards during assembly reflow (i.e. live-bug orientation).
For users, T shall not exceed the classification temperature in Table 4. For suppliers, T shall
c c
be equal to or exceed the classification temperature in Table 4.
NOTE 1 The temperature profile defined in Figure 1, Table 3 and Table 4 is the same as in IEC 60068-2-58:2015.
Thus, the temperature load used for testing resistance to soldering heat per each individual reflow treatment and
moisture sensitivity is the same.
NOTE 2 The temperature profile defined in Figure 1, Table 3 and Table 4 conforms with Figure 5-1 and Table 5-2
of J-STD-020E, which allow wider tolerances of, for example, peak temperature compared to the prescription given
in this document.
6.5 Recovery
The specimen shall be stored under the standard atmospheric conditions for measurements
and test as given in IEC 60068-1, (15 to 35) °C, (25 to 75) % RH for the time given in the
relevant specification.
6.6 Final measurements
6.6.1 Requirements
A component is considered to pass that level of moisture sensitivity if it passes the
requirements of 6.6.2 and 6.6.3, and if required, the non-destructive inspection of 6.6.4.
6.6.2 Visual inspection
Visual inspection shall be performed after the test. Special attention shall be paid to external
cracks and swelling which will be looked for under a magnification of 40×.
A device shall be considered as failure if it exhibits any of the following:
a) external crack visible using 40× optical microscope;
b) internal crack or delamination that intersects internal connections;
c) internal crack or delamination extending from any terminal to any other internal element
relevant for the function of the device;
d) internal crack or delamination extending more than 2/3 the distance from any internal
element relevant for the function of the device to the outside of the package;
e) changes in package body flatness caused by warpage, swelling or bulging invisible to the
naked eye;
f) dimensions out of specification.
Hot temperature warpage may be specified for multi-pin devices. If parts meet in hot condition
co-planarity and standoff dimensions as specified at room temperature, they shall be
considered passing.
The relevant specification may prescribe additional inspection criteria.
If internal cracks are detected by non-destructive inspection in 6.6.4, they are considered a
failure or verified good using polished cross sections through the identified site.
For packages known to be sensitive to vertical cracks, it is recommended that polished cross
sections be used to confirm the nonexistence of near vertical cracks within the mould
compound or encapsulant.
– 16 – IEC 61760-4:2015+AMD1:2018 CSV
© IEC 2018
6.6.3 Electrical measurements
Electrical measurements on all devices shall be performed as required by the relevant
specification, e.g. datasheet, detail specifications, etc.
6.6.4 Non-destructive inspection (if required)
If required by the relevant specification, non-destructive inspection (e.g. x-ray computed
tomography, scanning acoustic microscopy, etc.) shall be performed.
6.7 Classification
If one or more devices in the test sample fail at final measurements, the package shall be
considered not to have passed the tested level.
If a device does not pass level 5, it is classified as extremely moisture sensitive and dry pack
will not provide adequate protection. If such devices are shipped, the customer shall be
advised of its classification. The supplier shall also include a warning label with the devices
indicating that those either shall be socket mounted, or baked dry within a time given on the
label before reflow soldering.
6.8 Information to be given in the relevant specification
The following details shall be specified in the relevant specification:
a) MSL and classification temperature profile;
b) reject criteria, including non-destru
...