EN IEC 60749-21:2026

SLOVENSKI STANDARD
01-marec-2026
Nadomešča:
SIST EN 60749-21:2011
Polprevodniški elementi - Metode za mehansko in klimatsko preskušanje - 21. del:
Spajkljivost (IEC 60749-21:2025)
Semiconductor devices - Mechanical and climatic test methods - Part 21: Solderability
(IEC 60749-21:2025)
Halbleiterbauelemente - Mechanische und klimatische Prüfverfahren - Teil 21: Lötbarkeit
(IEC 60749-21:2025)
Dispositifs à semiconducteurs - Méthodes d’essais mécaniques et climatiques - Partie
21: Brasabilité (IEC 60749-21:2025)
Ta slovenski standard je istoveten z: EN IEC 60749-21:2026
ICS:
19.020 Preskuševalni pogoji in Test conditions and
postopki na splošno procedures in general
31.080.01 Polprevodniški elementi Semiconductor devices in
(naprave) na splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60749-21

NORME EUROPÉENNE
EUROPÄISCHE NORM January 2026
ICS 31.080.01 Supersedes EN 60749-21:2011
English Version
Semiconductor devices - Mechanical and climatic test methods -
Part 21: Solderability
(IEC 60749-21:2025)
Dispositifs à semiconducteurs - Méthodes d'essais Halbleiterbauelemente - Mechanische und klimatische
mécaniques et climatiques - Partie 21: Brasabilité Prüfverfahren - Teil 21: Lötbarkeit
(IEC 60749-21:2025) (IEC 60749-21:2025)
This European Standard was approved by CENELEC on 2026-01-13. 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 60749-21:2026 E

European foreword
The text of document 47/2961/FDIS, future edition 3 of IEC 60749-21, prepared by TC 47
"Semiconductor devices" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 60749-21:2026.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2027-01-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2029-01-31
document have to be withdrawn
This document supersedes EN 60749-21:2011 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 60749-21:2025 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 60068-2-69 NOTE Approved as EN 60068-2-69
IEC 60749-15 NOTE Approved as EN IEC 60749-15
IEC 60749-20 NOTE Approved as EN IEC 60749-20
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 61190-1-2 2014 Attachment materials for electronic EN 61190-1-2 2014
assembly - Part 1-2: Requirements for
soldering pastes for high-quality
interconnects in electronics assembly
IEC 61190-1-3 2017 Attachment materials for electronic EN IEC 61190-1-3 2018
assembly - Part 1-3: Requirements for
electronic grade solder alloys and fluxed
and non-fluxed solid solder for electronic
soldering applications
IEC 60749-21 ®
Edition 3.0 2025-12
INTERNATIONAL
STANDARD
Semiconductor devices - Mechanical and climatic test methods -
Part 21: Solderability
ICS 31.080.01  ISBN 978-2-8327-0902-3

IEC 60749-21:2025-12(en)
IEC 60749-21:2025 © IEC 2025
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Test apparatus and materials . 5
4.1 Solder bath . 5
4.2 Dipping device . 5
4.3 Optical equipment . 6
4.4 Steam ageing equipment . 6
4.5 Lighting equipment . 6
4.6 Materials . 6
4.6.1 Flux . 6
4.6.2 Solder . 7
4.7 SMD reflow equipment . 7
4.7.1 Stencil or screen . 7
4.7.2 Rubber squeegee or metal spatula . 7
4.7.3 Test substrate . 8
4.7.4 Solder paste . 8
4.7.5 Reflow equipment . 9
4.7.6 Flux removal solvent . 9
5 Procedures . 9
5.1 Lead-free backward compatibility . 9
5.2 Preconditioning . 9
5.2.1 General . 9
5.2.2 Preconditioning by steam ageing . 9
5.2.3 Preconditioning by high temperature storage . 10
5.3 Dip and look solderability testing . 10
5.3.1 General . 10
5.3.2 Solder dip conditions . 11
5.3.3 Procedure . 11
5.4 Procedure for simulated board mounting reflow solderability testing of SMDs . 16
5.4.1 General . 16
5.4.2 Test equipment set-up . 17
5.4.3 Specimen preparation and surface condition . 18
5.4.4 Visual inspection . 19
6 Summary . 19
Bibliography . 20

Figure 1 – Areas to be inspected for gullwing packages . 14
Figure 2 – Areas to be inspected for J-lead packages . 15
Figure 3 – Areas to be inspected in rectangular components (SMD method) . 15
Figure 4 – Areas to be inspected in SOIC and QFP packages (SMD method) . 16
Figure 5 – Flat peak type reflow profile . 18

Table 1 – Steam ageing conditions . 9
IEC 60749-21:2025 © IEC 2025
Table 2 – Altitude versus steam temperature . 10
Table 3 – Solder dip test conditions . 11
Table 4 – Maximum limits of solder bath contaminant . 13

IEC 60749-21:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Semiconductor devices -
Mechanical and climatic test methods -
Part 21: Solderability
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) 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 60749-21 has been prepared by IEC technical committee 47: Semiconductor devices. It is
an International Standard.
This third edition cancels and replaces the second edition published in 2011. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) revision to certain operating conditions in line with current working practices.
IEC 60749-21:2025 © IEC 2025
The text of this International Standard is based on the following documents:
Draft Report on voting
47/2961/FDIS 47/2982/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 60749 series, published under the general title Semiconductor
devices - Mechanical and climatic test methods 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 60749-21:2025 © IEC 2025
1 Scope
This part of IEC 60749 establishes a standard procedure for determining the solderability of
device package terminations that are intended to be joined to another surface using tin-lead
(SnPb) or lead-free (Pb-free) solder for the attachment.
This test method provides a procedure for “dip and look” solderability testing of through hole,
axial and surface mount devices (SMDs) as well as an optional procedure for a board mounting
solderability test for SMDs for the purpose of allowing simulation of the soldering process to be
used in the device application. The test method also provides optional conditions for ageing.
This test is considered destructive unless otherwise detailed in the relevant specification.
NOTE 1 This test method does not assess the effect of thermal stresses which can occur during the soldering
process. More details can be found in IEC 60749-15 or IEC 60749-20.
NOTE 2 If a qualitative test method is preferred, the Wetting balance test method can be found in IEC 60068-2-69.
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 61190-1-2:2014, Attachment materials for electronic assembly - Part 1-2: Requirements for
soldering pastes for high-quality interconnects in electronics assembly
IEC 61190-1-3:2017, Attachment materials for electronic assembly - Part 1-3: Requirements for
electronic grade solder alloys and fluxed and non-fluxed solid solders for electronic soldering
applications
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
– ISO Online browsing platform: available at https://www.iso.org/obp
– IEC Electropedia: available at https://www.electropedia.org
4 Test apparatus and materials
4.1 Solder bath
The solder bath shall be not less than 40 mm in depth and not less than 300 ml in volume such
that it can contain at least 1 kg of solder. The apparatus shall be capable of maintaining the
solder at the specified temperature within ±5 °C. The solder in solder baths used for
solderability testing shall be analysed or replaced to ensure that the composition complies with
4.6.2.
4.2 Dipping device
A mechanical dipping device capable of controlling the rates of immersion and emersion of the
terminations and providing a dwell time (time of total immersion to the required depth) in the
solder bath as specified shall be used.
IEC 60749-21:2025 © IEC 2025
4.3 Optical equipment
An optical microscope capable of providing magnification inspection from 10× to 20× shall be
used.
4.4 Steam ageing equipment
A non-corrodible container and cover of sufficient size to allow the placement of specimens
inside the vessel shall be used. The specimens shall be placed such that the lowest portion of
the specimen is a minimum of 40 mm above the surface of the water. A suitable method of
supporting the specimens shall be improvised using non-contaminating material.
During steam ageing, the test devices should be located in a manner so as to prevent water
(steam condensate) from dripping on them.
4.5 Lighting equipment
A lighting system shall be used that will provide a uniform, non-glare, non-directional
illumination of the specimen.
4.6 Materials
4.6.1 Flux
Unless otherwise detailed in the relevant specification, the flux for SnPb solderability tests shall
be a standard activated rosin flux (type ROL1 in accordance with Table 2 of
IEC 61190-1-3:2017), having a composition of 25 % ± 0,5 % by weight of colophony and
0,15 % ± 0,01 % by weight of diethylammonium hydrochloride, in 74,85 % ± 0,5 % by weight of
in 2-propanol (isopropanol). The specific gravity of the standard activated rosin flux shall be
0,843 ± 0,005 at (25 °C ± 2) °C.
The specification shall be as follows:
– Colophony
• colour: to WW colour specification or paler;
• acid value (mg KOH/g colophony): 155 (minimum);
• softening point (ball and ring): 70 °C (minimum);
• flow point (Ubbelohde): 76 °C (minimum);
• ash: 0,05 % (maximum);
• solubility: A solution of the colophony in an equal part by weight of 2-propanol
(isopropanol) shall be clear, and after a week at room temperature there shall be no sign
of a deposit.
– 2-propanol (isopropanol)
• purity: minimum 99,5 % 2-propanol (isopropanol) by weight;
• acidity as acetic acid: maximum 0,002 % weight (other than carbon dioxide);
• non-volatile matter: maximum 2 mg per 100 ml.
Unless otherwise detailed in the relevant specification, the flux for Pb-free solderability tests
shall be standard activated rosin flux having a composition of 25 % ± 0,5 % by weight of
colophony and (0,39 % ± 0,01) % by weight of diethylammonium hydrochloride, in
(74,61 % ± 0,5) % by weight of isopropyl.
--------------
...