SIST EN IEC 61760-4:2026

• Abstract:

  This part of IEC 61760 specifies the classification of moisture sensitive device into moisture sensitivity level related to soldering heat, and provisions for packaging, labelling and handling.; It extends the classification and packaging methods to such components, where currently existing standards are not required or not appropriate. For such cases, this document; introduces additional moisture sensitivity levels and an alternative method for packaging. This document 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 document and its relation to currently existing standards, e.g. IEC 60749-20 [1] or J-STD-020F [2] and J-STD-033 [3], are described in the Introduction.

• Status: Published
• Public Enquiry End Date: 14-Sep-2025
• Publication Date: 19-Aug-2026
• ICS: 31.190 - Electronic component assemblies
• Technical Committee: ITIV - Electronics assembly technology and Environmental standardization
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 29-Jul-2026
• Due Date: 03-Oct-2026
• Completion Date: 20-Aug-2026
• Ref Project: EN IEC 61760-4:2026 - Surface mounting technology - Part 4: Classification, packaging, labelling and handling of moisture sensitive devices

• Replaces: SIST EN 61760-4:2015 - Surface mounting technology - Part 4: Standard method for classification, packaging, labelling and handling of moisture sensitive devices
• Effective Date: 01-Sep-2026
• Refers: SIST EN 60068-1:2014 - Environmental testing - Part 1: General and guidance
• Effective Date: 23-Jun-2026
• Referred By: SIST EN IEC 62435-8:2020 - Electronic components - Long-term storage of electronic semiconductor devices - Part 8: Passive elecronic devices (IEC 62435-8:2020)
• Effective Date: 28-Jul-2026
• Referred By: SIST EN IEC 61760-1:2026 - Surface mounting technology - Part 1: Standard method for the specification of surface mounting components (SMDs).
• Effective Date: 28-Jul-2026
• Referred By: SIST EN IEC 62878-1:2021 - Device embedding assembly technology - Part 1: Generic specification for device embedded substrates
• Effective Date: 28-Jul-2026
• Referred By: SIST EN IEC 61760-1:2022 - Surface mounting technology - Part 1: Standard method for the specification of surface mounting components (SMDs)
• Effective Date: 28-Jul-2026
• Revises: SIST EN 61760-4:2015/A1:2018 - Surface mounting technology - Part 4: Classification, packaging, labelling and handling of moisture sensitive devices
• Effective Date: 01-Sep-2026

Overview

SIST EN IEC 61760-4:2026 specifies standardized procedures for the classification, packaging, labelling, and handling of moisture sensitive devices (MSDs) intended for use in surface mounting technology (SMT). Issued by the Slovenian Institute for Standardization (SIST), this standard provides manufacturers, suppliers, and electronics assembly organizations guidance to minimize risks related to moisture absorption in components during reflow soldering. Managing moisture sensitivity is vital for maintaining the reliability of electronic assemblies and mitigating issues such as delamination, cracking, and reduced component longevity.

Key Topics

The standard covers several essential areas relevant to surface mount devices and moisture control:

• Classification of Moisture Sensitivity:
  Devices are classified by their moisture sensitivity level (MSL), indicating their risk of damage when exposed to moisture and subsequent soldering heat.
• Packaging Requirements:
  Specifies the use of moisture barrier bags (MBBs), desiccants, and humidity indicator cards to protect MSDs during shipping and storage.
• Labelling Protocols:
  Details the information required on packaging labels, such as MSL, recommended environmental conditions, and handling instructions to maintain device integrity.
• Handling and Storage:
  Provides guidelines for storage conditions, shelf life, floor life (the allowable exposure time outside protective packaging), and unpacking and repacking procedures.
• Drying Procedures:
  Outlines methods and conditions for drying MSDs, including baking times and temperature profiles, to reduce residual moisture before assembly or re-packaging.
• Testing Methods:
  Describes standardized test profiles and procedures to evaluate a device’s resistance to combined effects of moisture and soldering heat, ensuring accurate MSL designation.

Applications

The requirements of SIST EN IEC 61760-4:2026 are applicable across the electronics industry, particularly where high-reliability assembly is essential. Key areas of application include:

• Electronics Manufacturing Services (EMS):
  Ensures compliance with best practices for handling and assembly of sensitive SMDs, reducing defects and rework.
• Component Suppliers:
  Provides a consistent framework for classifying and shipping moisture sensitive devices to customers worldwide.
• Quality Assurance and Compliance:
  Supports the implementation of robust moisture management systems within IPC-certified or ISO 9001 environments.
• Surface Mount Assembly:
  Critical for contract manufacturers and assembly plants using reflow soldering processes, where incorrect handling can result in device failure due to "popcorn" cracking or delamination.
• Stock Management and Logistics:
  Facilitates correct storage and inventory tracking, optimizing the use and shelf life of moisture sensitive components.

Related Standards

Effective management of moisture sensitive devices is closely linked with several other international standards:

• IEC 60749-20:
  Specializes in test methods for semiconductor devices, particularly plastic-encapsulated SMDs.
• J-STD-020 / J-STD-033:
  Widely recognized joint industry standards detailing moisture sensitivity levels and handling of MSDs, often cross-referenced in IEC 61760-4.
• IEC 61340-5-1:
  Addresses protection of electronic devices from electrostatic discharge (ESD), which is relevant during handling and packaging of moisture sensitive devices.
• IEC 60068-1 and IEC 60068-2-78:
  Provide broader guidance on environmental testing for electronic components, including humidity and soldering heat resistance.
• IEC 61760-2:
  Focuses on transportation and storage conditions specific to surface mounting devices.

Conclusion

Implementing SIST EN IEC 61760-4:2026 helps manufacturers and users of electronic components reduce failures, enhance reliability, and ensure compliance with international best practices for moisture management in SMT assembly. Proper classification, packaging, labelling, and handling of moisture sensitive devices are critical for quality assurance and protection throughout the supply chain. By following this standard, organizations can better safeguard their electronic assemblies against moisture-induced damage and optimize their production processes.

SLOVENSKI STANDARD
01-september-2026
Nadomešča:
SIST EN 61760-4:2015
Tehnologija površinske montaže - 4. del: Razvrščanje, pakiranje, etiketiranje in
ravnanje z napravami, občutljivimi na vlago
Surface mounting technology - Part 4: Classification, packaging, labelling and handling
of moisture sensitive devices
Oberflächenmontagetechnik - Teil 4: Genormtes Verfahren zur Klassifikation,
Verpackung, Kennzeichnung und Handhabung feuchteempfindlicher Bauteile
Technique du montage en surface - Partie 4: Classification, emballage, étiquetage et
manipulation des dispositifs sensibles à l’humidité
Ta slovenski standard je istoveten z: EN IEC 61760-4:2026
ICS:
31.190 Sestavljeni elektronski Electronic component
elementi assemblies
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 61760-4

NORME EUROPÉENNE
EUROPÄISCHE NORM July 2026
ICS 31.190 Supersedes EN 61760-4:2015; EN 61760-4:2015/A1:2018
English Version
Surface mounting technology - Part 4: Classification, packaging,
labelling and handling of moisture sensitive devices
(IEC 61760-4:2026)
Technologie de montage en surface - Partie 4: Oberflächenmontagetechnik - Teil 4: Genormtes Verfahren
Classification, emballage, étiquetage et manipulation des zur Klassifikation, Verpackung, Kennzeichnung und
dispositifs sensibles à l'humidité Handhabung feuchteempfindlicher Bauteile
(IEC 61760-4:2026) (IEC 61760-4:2026)
This European Standard was approved by CENELEC on 2026-07-02. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61760-4:2026 E

European foreword
The text of document 91/2101/FDIS, future edition 2 of IEC 61760-4, prepared by TC 91 "Electronics
assembly technology" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC
as EN IEC 61760-4:2026.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2027-07-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2029-07-31
document have to be withdrawn
This document supersedes EN 61760-4:2015 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 61760-4:2026 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standard indicated:
IEC 60749-20 NOTE Approved as EN IEC 60749-20
IEC 60068-2-78 NOTE Approved as EN IEC 60068-2-78
IEC 60068-2-58:2015 NOTE Approved as EN 60068-2-58:2015 (not modified)
IEC 60068-2-58 NOTE Approved as EN 60068-2-58
ISO 62 NOTE Approved as EN ISO 62
IEC 61760-2 NOTE Approved as EN IEC 61760-2
IEC 61340-5-1 NOTE Approved as EN IEC 61340-5-1
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60068-1 2013 Environmental testing - Part 1: General EN 60068-1 2014
and guidance
IEC 61760-4 ®
Edition 2.0 2026-05
INTERNATIONAL
STANDARD
Surface mounting technology -
Part 4: Classification, packaging, labelling and handling of moisture sensitive
devices
ICS 31.190  ISBN 978-2-8327-1256-6

IEC 61760-4:2026-05(en)
IEC 61760-4:2026 © IEC 2026
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 General information . 8
4.1 Moisture sensitive devices . 8
4.2 Moisture sensitivity level (MSL) . 8
4.3 Relation to other environmental test methods (humidity tests) . 8
5 Assessment of moisture sensitivity . 9
5.1 Identification of non-moisture sensitive devices . 9
5.2 Classification . 9
6 Test procedure . 10
6.1 General . 10
6.1.1 Structurally similar components . 10
6.1.2 Verification and validation tests . 10
6.1.3 Selection of applicable soak conditions and temperature profile . 10
6.2 Drying . 10
6.3 Moisture soak . 10
6.4 Temperature load. 11
6.4.1 Classification temperature profile . 11
6.4.2 Classification temperature profile for special devices . 12
6.4.3 Reflow . 12
6.5 Recovery . 13
6.6 Final measurements. 13
6.6.1 Requirements . 13
6.6.2 Visual inspection . 13
6.6.3 Electrical measurements . 14
6.6.4 Non-destructive inspection (if required) . 14
6.7 Classification . 14
6.8 Information to be given in the relevant specification . 14
7 Requirements to packaging and labelling . 14
7.1 Packaging process . 14
7.1.1 Drying of MSDs and carrier materials before being sealed in MBBs . 14
7.1.2 Evacuation and sealing . 15
7.2 Packaging material for dry pack . 15
7.2.1 Moisture barrier bag (MBB) . 15
7.2.2 Desiccant . 16
7.2.3 Humidity indicator . 18
7.3 Information to be given on labels . 18
8 Handling of moisture sensitive devices . 19
8.1 Storage . 19
8.1.1 Recommended storage conditions . 19
8.1.2 Shelf life . 19
8.1.3 Floor life . 20
8.2 ESD . 20
IEC 61760-4:2026 © IEC 2026
8.3 Humidity indication. 20
8.3.1 Humidity indicator card (HIC) . 20
8.3.2 Moisture indicating desiccant . 21
8.4 Unpacking and re-packing. 21
9 Drying . 21
9.1 Drying options . 21
9.2 Methods . 22
9.2.1 General considerations for baking . 22
9.2.2 Bakeout times . 23
9.2.3 ESD protection . 23
9.2.4 Reuse of carriers . 23
9.2.5 Solderability limitations . 23
Annex A (informative) Moisture sensitivity of assemblies . 24
Annex B (informative) Mass/gain loss analysis . 25
Annex C (informative) Baking of devices . 26
C.1 Baking time and conditions . 26
C.2 Example of a baking process . 26
Annex D (normative) Moisture sensitivity labels . 27
D.1 Object . 27
D.2 Graphical symbols and labels . 27
D.2.1 Graphical symbols for moisture sensitivity . 27
D.2.2 Moisture sensitivity identification label (MSID) . 28
D.2.3 Moisture sensitivity caution label (MSCL) . 28
Bibliography . 30

Figure 1 – Classification temperature profile . 11
Figure 2 – Examples of humidity indicator cards . 18
Figure C.1 – Baking process . 26
Figure D.1 – Standardized graphical symbol for Moisture sensitive devices (IEC 60417-
6093:2011-10), for use on equipment . 27
Figure D.2 – Example of a moisture sensitivity symbol used on components and
packaging labels (as seen in JEDEC JEP113 [15]). 28
Figure D.3 – MSID labels (examples) . 28

Table 1 – Moisture sensitivity levels . 9
Table 2 – Moisture soak conditions . 10
Table 3 – Parameters of the classification temperature profile . 12
Table 4 – Classification temperatures T . 12
c
Table 5 – MBB material properties . 16
Table 6 – Conditions for re-bake – Example for one type of plastic encapsulated
devices . 21
Table 7 – Conditions for baking prior to dry pack – Example for one type of plastic
encapsulated devices . 22

IEC 61760-4:2026 © IEC 2026
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,
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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.
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6) All users should ensure that they have the latest edition of this publication.
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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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s).
IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect
thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which may
be required to implement this document. However, implementers are cautioned that this may not represent the
latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC shall
not be held responsible for identifying any or all such patent rights.
IEC 61760-4 has been prepared by IEC technical committee 91: Electronics assembly
technology. It is an International Standard.
This second edition cancels and replaces the first edition published in 2015 and
Amendment 1:2018. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) The content is updated to cover the classification conditions given in the new editions of J-
STD-020F and IEC 60068-2-58.
IEC 61760-4:2026 © IEC 2026
The text of this International Standard is based on the following documents:
FDIS Report on voting
91/2101/FDIS 91/2111/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
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 document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
– reconfirmed,
– withdrawn, or
– revised.
IEC 61760-4:2026 © IEC 2026
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 [1]), but not for other types of components.
This part of IEC 61760 also extends the classification and packaging methods as described in
J-STD-020F [2] and J-STD-033 [3]. It is intended to be used for such type of components, where
J-STD-020F [2] and J-STD-033 [3] are not required or not appropriate.
It is important to note that moisture sensitivity levels existing in both J-STD-020F [2] and this
document are equivalent.
IEC 61760-4:2026 © IEC 2026
1 Scope
This part of IEC 61760 specifies the classification of moisture sensitive device into moisture
sensitivity level related to soldering heat, and provisions for packaging, labelling and handling.
It extends the classification and packaging methods to such components, where currently
existing standards are not required or not appropriate. For such cases, this document
introduces additional moisture sensitivity levels and an alternative method for packaging.
This document 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 document and its relation to currently existing standards, e.g. IEC 60749-20 [1] or
J-STD-020F [2] and J-STD-033 [3], are described in the Introduction.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60068-1:2013, Environmental testing - Part 1: General and guidance
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
– IEC Electropedia: available at https://www.electropedia.org/
– ISO Online browsing platform: available at https://www.iso.org/obp
3.1
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.
IEC 61760-4:2026 © IEC 2026
3.3
moisture barrier bag
MBB
bag designed to restrict the transmission of water vapour and used to pack moisture sensitive
devices (3.1)
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 (3.3) 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
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.
3.9
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.
3.10
water vapour transmission rate
WVTR
measure of the permeability of a plastic film material to moisture, used to specify a moisture
barrier bag (3.3) for dry packing
Note 1 to entry: This note applies to the French language only.
IEC 61760-4:2026 © IEC 2026
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 or delamination to the
device during the soldering process (e.g. “popcorn phenomenon”), which can adversely affect
reliability.
NOTE “Popcorn phenomenon” defines 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 to remove them immediately prior to soldering onto the circuit board. 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.
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, for example as in IEC 60068-2-78 [4], devices are tested either in 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 document is to test the resistance of devices
against the soldering heat in combination with the humidity load as preconditioning process.
IEC 61760-4:2026 © IEC 2026
Other effects of humidity, like deterioration of electrical characteristics or isolation properties,
are not covered by this document and shall 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 can 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. See Annex A for the classification of semi-finished assemblies.
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 suppliers and users agree, components can be classified at temperatures other than those
in Table 4.
If the conditions in Table 1 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 Desicca Humidity
time condition nt indicator
(reference
condition)
1 a ≤30 °C/85 % RH 12 months No requirement

or as
2 a ≤30 °C/60 % RH b No Optional
specified
1 year MBB type 1 , <60 % RH in
c
by the
MBB no pre-drying
supplier
C2a 4 weeks ≤30 °C/60 % RH b Yes c
MBB type 1 , <30 % RH in Yes
MBB no pre-drying
2a b
MBB type 2 , <10 % RH
in MBB pre-drying
C3 168 h ≤30 °C/60 % RH b Yes c
MBB type 1 , <30 % RH in Yes
MBB no pre-drying
3 b
MBB type 2 , <10 % RH
in MBB pre-drying
4 72 h ≤30 °C/60 % RH b Yes c
MBB type 2 , <10 % RH Yes
in MBB pre-drying
5 48 h ≤30 °C/60 % RH c Yes c
MBB type 2 , <10 % RH Yes
in MBB pre-drying
IEC 61760-4:2026 © IEC 2026
LEVEL floor life Floor life shelf life Protective packaging Desicca Humidity
time condition nt indicator
(reference
condition)
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 requires 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 water vapour transmission rate (WVTR) 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.
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 [5] 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
The specimen shall be baked at 125 °C ± 5 °C for at least 24 h, unless otherwise specified in
the relevant specification.
However, alternative baking conditions may 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
LEVEL Soak time (h) a Alternative
Soak condition
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 –
C2a (168 +5/−0) (85 ± 2) °C, (30 ± 5) % RH, –
followed by followed by (30 ± 2) °C,
(672 +5/−0) (60 ± 5) % RH
2a (696 + 5/−0) (30 ± 2) °C, (60 ± 5) % RH
C3 (168 +5/−0) (85 ± 2) °C, (30 ± 5) % RH,
followed by followed by (30 ± 2) °C,
(168 +5/−0) (60 ± 5) % RH
IEC 61760-4:2026 © IEC 2026
LEVEL Soak time (h) a Alternative
Soak condition
3 (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, one year) in
the MBB type 1. The second stage of soak condition corresponds to floor life (as in IEC 60749-20 [1]).
a
Soak conditions according to J-STD-020F [2]. Alternatively accelerated equivalent soak conditions from
Table 4 in J-STD-020F [2] may be applied in case the activation energy is confirmed by the manufacturer.
6.4 Temperature load
6.4.1 Classification temperature profile

Key
Minimum preheating temperature
T
Maximum preheating temperature
T
Liquidus temperature
T
Classification temperature
T
c
Preheating duration
t
Time at liquidus
t
t Time within (T – 5 °C)
3 c
t Time to T
4 c
a Temperature gradient of the increasing slope
b Preheat area
c Temperature gradient of the decreasing slope
The temperature gradient of the increasing slope shall not exceed 3 K/s and the temperature
gradient of the decreasing slope shall not exceed 6 K/s.
Figure 1 – Classification temperature profile

IEC 61760-4:2026 © IEC 2026
Table 3 – Parameters of the classification temperature profile
Solder Sn-Pb (or equivalent) SnAgCu (or equivalent) Sn-Bi (or equivalent)
process
100 °C 150 °C 100 °C
T
150 °C 200 °C 120 °C
T
(60 to 120) s (60 to 120) s (30 to 90) s
t
183 °C 217 °C 139 °C
T
(60 to 150) s (60 to 150) s (60 to 150) s
t
20 s 30 s 20 s
t
See Table 4
T
c
≤6 min ≤8 min ≤4 min
t
Table 4 – Classification temperatures T
c
Solder process Package
Classification temperature T for package volume
c
thickness
3 3 3
<350 mm 350 mm to >2 000 mm
2 000 mm
mm °C °C °C
SnPb (or <2,5 235 220 220
equivalent)
≥2,5 220 220 220
SnAgCu (or <1,6 260 260 260
equivalent)
1,6 to 2,5 260 250 245
>2,5 250 245 245
>2,5 plus high not applicable b b
230 230
a
thermal capacity
Sn-Bi (or All package thickness and volume: 190
equivalent)
[LTS]
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
T measured at the device terminal or solder joint shall achieve the minimum temperature and time necessary
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 or thermal sensitivity) the temperature profiles
in IEC 60068-2-58:2015 [6], Table 7, can be used. Other profiles may be specified in the
relevant specification according to the agreement between user and supplier. For information
see also J-STD 075A [7].
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 of 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.
IEC 61760-4:2026 © IEC 2026
If the timing between removal from climatic test chamber and initial reflow cannot be met, the
parts shall be rebaked and resoaked according to 6.2 and 6.3.
All temperatures refer to the centre of the package, measured on the package body surface
that is facing up during assembly reflow (for example live-bug orientation).
For users, Tc shall not exceed the classification temperature in Table 4. For suppliers Tc shall
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 comparable to the test conditions and
severities specified in IEC 60068-2-58 [8]. Thus, the temperature load used for testing resistance to soldering heat
per each individual reflow treatment and for moisture sensitivity is equivalent.
NOTE 2 The temperature profile defined in Figure 1, Table 3 and Table 4conforms with Figure 1 and Table 5 of
J-STD-020F [2], 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 60068-1:2013, (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
coplanarity and stand-off 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 non-existence of near vertical cracks within the mould
compound or encapsulant.
IEC 61760-4:2026 © IEC 2026
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-destructive inspection criteria, in addition to those from 6.6.2
to 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.
The manufacturer’s exposure time (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,
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