EN 60068-2-58:2015

SLOVENSKI STANDARD
01-september-2015
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Environmental testing - Part 2-58: Tests - Test Td: Test methods for solderability,
resistance to dissolution of metallization and to soldering heat of surface mounting
devices (SMD)
Umweltprüfungen - Teil 2-58: Prüfungen - Prüfung Td: Prüfverfahren für Lötbarkeit,
Widerstandsfähigkeit gegenüber Auflösen der Metallisierung und Lötwärmebeständigkeit
bei oberflächenmontierbaren Bauelementen (SMD)
Essais d'environnement - Partie 2-58: Essais - Essai Td: Méthodes d'essai de la
soudabilité, résistance de la métallisation à la dissolution et résistance à la chaleur de
brasage des composants pour montage en surface (CMS)
Ta slovenski standard je istoveten z: EN 60068-2-58:2015
ICS:
19.040 Preskušanje v zvezi z Environmental testing
okoljem
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 60068-2-58

NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2015
ICS 19.040; 31.190 Supersedes EN 60068-2-58:2004
English Version
Environmental testing - Part 2-58: Tests - Test Td: Test methods
for solderability, resistance to dissolution of metallization and to
soldering heat of surface mounting devices (SMD)
(IEC 60068-2-58:2015)
Essais d'environnement - Partie 2-58: Essais - Essai Td: Umweltprüfungen - Teil 2-58: Prüfungen - Prüfung Td:
Méthodes d'essai de la soudabilité, résistance de la Prüfverfahren für Lötbarkeit, Widerstandsfähigkeit
métallisation à la dissolution et résistance à la chaleur de gegenüber Auflösen der Metallisierung und
brasage des composants pour montage en surface (CMS) Lötwärmebeständigkeit bei oberflächenmontierbaren
(IEC 60068-2-58:2015) Bauelementen (SMD)
(IEC 60068-2-58:2015)
This European Standard was approved by CENELEC on 2015-05-01. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 60068-2-58:2015 E
Foreword
The text of document 91/1222/FDIS, future edition 4 of IEC 60068-2-58, prepared by IEC/TC 91
"Electronics assembly technology" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN 60068-2-58:2015.
The following dates are fixed:
(dop) 2016-02-01
• latest date by which the document has to be implemented at
national level by publication of an identical national
standard or by endorsement
(dow) 2018-05-01
• latest date by which the national standards conflicting with
the document have to be withdrawn

This document supersedes EN 60068-2-58:2004.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
Endorsement notice
The text of the International Standard IEC 60068-2-58:2015 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60068-2-54 NOTE Harmonized as EN 60068-2-54.
IEC 60068-2-69 NOTE Harmonized as EN 60068-2-69.
IEC 60749-20 NOTE Harmonized as EN 60749-20.
IEC 61760-3 NOTE Harmonized as EN 61760-3.
1)
IEC 61760-4 NOTE Harmonized as EN 61760-4 .

1) To be published.
- 3 - EN 60068-2-58:2015
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is
available here: www.cenelec.eu.

Publication Year Title EN/HD Year
IEC 60068-1 -  Environmental testing - EN 60068-1 -
Part 1: General and guidance
IEC 60068-2-20 2008 Environmental testing - EN 60068-2-20 2008
Part 2-20: Tests - Test T: Test methods for
solderability and resistance to soldering
heat of devices with leads
IEC 60194 -  Printed board design, manufacture and EN 60194 -
assembly - Terms and definitions
IEC 61190-1-1 -  Attachment materials for electronic EN 61190-1-1 -
assembly -
Part 1-1: Requirements for soldering fluxes
for high-quality interconnections in
electronics assembly
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 2007 Attachment materials for electronic EN 61190-1-3 2007
assembly -
+ A1 2010 + A1 2010
Part 1-3: Requirements for electronic grade
solder alloys and fluxed and non-fluxed
solid solders for electronic soldering
applications
IEC 61191-2 -  Printed board assemblies - EN 61191-2 -
Part 2: Sectional specification -
Requirements for surface mount soldered
assemblies
Publication Year Title EN/HD Year
IEC 61249-2-22 -  Materials for printed boards and other EN 61249-2-22 -
interconnecting structures -
Part 2-22: Reinforced base materials, clad
and unclad - Modified non-halogenated
epoxide woven E-glass laminated sheets of
defined flammability (vertical burning test),
copper-clad
IEC 61249-2-35 -  Materials for printed boards and other EN 61249-2-35 -
interconnecting structures -
Part 2-35: Reinforced base materials, clad
and unclad - Modified epoxide woven
E-glass laminate sheets of defined
flammability (vertical burning test), copper-
clad for lead-free assembly
IEC 61760-1 -  Surface mounting technology - EN 61760-1 -
Part 1: Standard method for the
specification of surface mounting
components (SMDs)
ISO 9454-2 1998 Soft soldering fluxes - Classification and EN ISO 9454-2 2000
requirements -
Part 2: Performance requirements

IEC 60068-2-58 ®
Edition 4.0 2015-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Environmental testing –
Part 2-58: Tests – Test Td: Test methods for solderability, resistance to

dissolution of metallization and to soldering heat of surface mounting devices

(SMD)
Essais d’environnement –
Partie 2-58: Essais – Essai Td: Méthodes d’essai de la soudabilité, résistance de

la métallisation à la dissolution et résistance à la chaleur de brasage des

composants pour montage en surface (CMS)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 19.040; 31.190 ISBN 978-2-8322-2436-6

– 2 – IEC 60068-2-58:2015 © IEC 2015
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references. 7
3 Terms and definitions . 8
4 Grouping of soldering processes and related test severities . 9
5 Test equipment . 10
5.1 Solder bath . 10
5.2 Reflow equipment . 10
6 Test Td : Solderability of terminations . 11
6.1 Object and general description of the test . 11
6.2 Specimen preparation . 11
6.3 Accelerated ageing . 11
6.4 Initial measurements . 11
6.5 Method 1: Solder bath . 11
6.5.1 Solder bath . 11
6.5.2 Solder and flux . 11
6.5.3 Test procedure and conditions . 12
6.6 Method 2: Reflow . 14
6.6.1 Reflow equipment . 14
6.6.2 Solder paste . 14
6.6.3 Test substrates . 14
6.6.4 Test procedure . 14
6.6.5 Reflow temperature profile for Test Td . 15
6.6.6 Test conditions . 16
7 Test Td : Resistance to soldering heat . 16
7.1 Object and general description of the test . 16
7.2 Specimen preparation . 16
7.3 Preconditioning . 16
7.4 Initial measurements . 16
7.5 Method 1: Solder bath . 17
7.5.1 Solder bath . 17
7.5.2 Solder and flux . 17
7.5.3 Test procedure and conditions . 17
7.6 Method 2: Reflow . 19
7.6.1 Reflow equipment . 19
7.6.2 Solder paste . 19
7.6.3 Test substrates . 19
7.6.4 Test procedure and conditions . 19
8 Test Td : Dewetting and resistance to dissolution of metallization . 21
8.1 Object and general description of the test . 21
8.2 Specimen preparation . 21
8.3 Initial measurements . 22
8.4 Method 1: Solder bath . 22
8.4.1 Solder bath . 22
8.4.2 Solder and flux . 22

IEC 60068-2-58:2015 © IEC 2015 – 3 –
8.4.3 Test procedure and conditions . 22
8.5 Method 2: Reflow . 22
8.5.1 Reflow equipment . 22
8.5.2 Specimen. 22
8.5.3 Solder paste . 22
8.5.4 Flux . 22
8.5.5 Reflow profile . 22
8.5.6 Placement of the specimen . 23
8.5.7 Application of the reflow profile. 23
8.5.8 Evaluation . 23
9 Final measurements . 23
9.1 Flux removal . 23
9.2 Recovery conditions . 23
9.3 Evaluation . 23
9.3.1 Wetting . 23
9.3.2 Dewetting . 24
9.3.3 Resistance to soldering heat . 24
9.3.4 Resistance to dissolution of metallization . 24
10 Information to be given in the relevant specification . 25
10.1 General . 25
10.2 Solderability . 25
10.3 Resistance to soldering heat, dewetting and resistance to dissolution of
metallization. 25
Annex A (normative) Criteria for visual examination . 27
A.1 Wetting . 27
A.2 Evaluation of wetting . 27
A.3 Evaluation of method 2 (Td ) . 28
A.4 Evaluation of method 2 (Td ) . 29
Annex B (informative) Guidance . 30
B.1 General . 30
B.2 Limitations . 30
B.3 Choice of severity . 30
B.3.1 Test Td : Solderability by solder bath method . 30
B.3.2 Test Td : Resistance to soldering heat – Solder bath method . 31
B.3.3 Test Td : Resistance to soldering heat –Reflow method . 31
B.3.4 Immersion attitude . 32
B.3.5 Test Td : Dewetting and resistance to dissolution of metallization for
30 s at 260 °C . 32
Annex C (normative) Application of the test methods to through hole reflow soldering
components (THR) . 33
C.1 Solderability . 33
C.2 Resistance to soldering heat . 33
C.3 Dewetting. 33
C.4 Criteria for evaluation . 33
Annex X (informative) Cross reference for references to the prior revision of this
specification . 34
Bibliography . 36

– 4 – IEC 60068-2-58:2015 © IEC 2015

Figure 1 – Examples of immersion attitudes . 13
Figure 2 – Reflow temperature profile for solderability . 15
Figure 3 – Examples of immersion attitude . 18
Figure 4 – Reflow temperature profile for resistance to soldering heat . 20
Figure 5 – Example for placement of a specimen to a test substrate . 23
Figure 6 – Identification of areas on metallic termination . 24
Figure A.1 – Evaluation of wetting . 28

Table 1 – Grouping of soldering processes and typical test severities – Overview . 10
Table 2 – Solder alloy and flux for test Td . 12
Table 3 – Solderability – Test conditions and severity, solder bath method . 14
Table 4 – Solder paste specification . 14
Table 5 – Solderability – Test conditions – Method 2: Reflow . 16
Table 6 – Resistance to soldering heat – Test conditions and severity, solder bath
method . 19
Table 7 – Resistance to soldering heat – Test conditions and severity, reflow method . 21
Table 8 – Dewetting and resistance to dissolution of metallization – Test conditions
and severity, solder bath method . 22
Table B.1 – Test conditions . 31
Table C.1 – Test conditions for solderability test . 33

IEC 60068-2-58:2015 © IEC 2015 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ENVIRONMENTAL TESTING –
Part 2-58: Tests –
Test Td: Test methods for solderability, resistance
to dissolution of metallization and to soldering heat
of surface mounting devices (SMD)

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 60068-2-58 has been prepared by IEC technical committee 91:
Electronics assembly technology.
This fourth edition cancels and replaces the third edition, published in 2004 and constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
– the addition of Sn-Bi low temperature solder alloy;
– the addition of several reflow test conditions in Table 7 – Resistance to soldering heat –
Test conditions and severity, reflow method;
– introduction of reflow test method for Test Td : Dewetting and resistance to dissolution of
metallization;
– 6 – IEC 60068-2-58:2015 © IEC 2015
– implementation of guidance for the choice of a test severity in Clause B.3.
The text of this standard is based on the following documents:
FDIS Report on voting
91/1222/FDIS 91/1250/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 60068, published under the general title Environmental testing,
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 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.
IEC 60068-2-58:2015 © IEC 2015 – 7 –
ENVIRONMENTAL TESTING –
Part 2-58: Tests –
Test Td: Test methods for solderability, resistance
to dissolution of metallization and to soldering heat
of surface mounting devices (SMD)

1 Scope
This part of IEC 60068 outlines test Td, applicable to surface mounting devices (SMD).
This standard provides procedures for determining the solderability and resistance to
soldering heat of devices in applications using solder alloys, which are eutectic or near
eutectic tin lead (Pb), or lead-free alloys.
The procedures use either a solder bath or reflow method and are applicable only to
specimens or products designed to withstand short term immersion in molten solder or limited
exposure to reflow systems.
The solder bath method is applicable to SMDs designed for flow soldering and SMDs
designed for reflow soldering when the solder bath (dipping) method is appropriate.
The reflow method is applicable to the SMD designed for reflow soldering, to determine the
suitability of SMDs for reflow soldering and when the solder bath (dipping) method is not
appropriate.
The objective of this standard is to ensure solderability of component lead or termination. In
addition, test methods are provided to ensure that the component body can resist against the
heat load to which it is exposed during soldering.
This standard covers tests Td , Td and Td as listed below:
1 2 3
Number of Td Test Method
Method 1: Solder bath
Td
Solderability of terminations
Method 2: Reflow
Method 1: Solder bath
Td
Resistance to soldering heat
Method 2: Reflow
Method 1: Solder bath
Td
Dewetting and resistance to dissolution of metallization
Method 2: Reflow
NOTE 1 For specific components other test methods may exist.
NOTE 2 Test Td does not apply to printed wiring board (PWB), see IEC 61189-3.
NOTE 3 Specific through-hole devices (where the device supplier has specifically documented support for reflow
soldering) are also included in this standard.
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 60068-2-20:2008, Environmental testing – Part 2-20: Tests – Test T: Test methods for
solderability and resistance to soldering heat of devices with leads

– 8 – IEC 60068-2-58:2015 © IEC 2015
IEC 60194, Printed board design, manufacture and assembly – Terms and definitions
IEC 61190-1-1, Attachment materials for electronic assemblies – Part 1-1: Requirements for
soldering fluxes for high-quality interconnections in electronics assembly
IEC 61190-1-2:2014, Attachment materials for electronic assembly – Part 1-2: Requirements
for solder pastes for high-quality interconnections in electronics assembly
IEC 61190-1-3:2007, 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
IEC 61190-1-3:2007/AMD1:2010
IEC 61191-2, Printed board assemblies – Part 2: Sectional specification – Requirements for
surface mount soldered assemblies
IEC 61249-2-22, Materials for printed boards and other interconnecting structures – Part 2-
22: Reinforced base materials clad and unclad – Modified non-halogenated epoxide woven E-
glass laminated sheets of defined flammability (vertical burning test), copper-clad
IEC 61249-2-35, Materials for printed boards and other interconnecting structures – Part 2-
35: Reinforced base materials, clad and unclad – Modified epoxide woven E-glass laminate
sheets of defined flammability (vertical burning test), copper-clad for lead-free assembly
IEC 61760-1, Surface mounting technology – Part 1: Standard method for the specification
of surface mounting components (SMDs)
ISO 9454-2:1998, Soft soldering fluxes – Classification and requirements – Part 2:
Performance requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60068-1,
IEC 60068-2-20, IEC 60194, and the following apply.
3.1
solderability
ability of the termination or electrode of the SMD to be wetted by solder at the temperature of
the termination or electrode, which is assumed to be the lowest temperature in the soldering
process, within the applicable temperature range of the solder alloy
3.2
resistance to soldering heat
ability of the component to withstand the highest temperature in terms of temperature gradient,
peak temperature and duration of the soldering process, within the applicable temperature
range of the solder alloy
3.3
flow soldering
wave, drag or dip soldering process where the product is brought into contact with molten
solder in order to attach electronic components to the interconnecting surface
3.4
reflow soldering
joining of surfaces that have been tinned and/or have solder between them, placing them
together, heating them until the solder flows, and allowing the surface and the solder to cool
in the joined position
3.5
wetting
formation of an adherent coating of solder on a surface indicated by a small contact angle

IEC 60068-2-58:2015 © IEC 2015 – 9 –
3.6
dewetting
retraction of molten solder on a solid area that it has initially wetted
Note 1 to entry: In some cases an extremely thin film of solder may remain. As the solder retracts the contact
angle increases.
3.7
non-wetting
inability to form an adherent coating of solder on a surface indicated by a contact angle
greater than 90°
3.8
dissolution of metallization
process of dissolving metal, usually by introduction of chemicals
3.9
pinhole
small hole that penetrates from the surface of a solder to base material
4 Grouping of soldering processes and related test severities
The melting temperatures of lead-free solder alloys selected for industrial processes are
significantly different from those for Sn-Pb solder alloy. Moreover, the melting temperatures of
lead-free solder alloys are different from each other but can be clustered in groups.
The following groups of soldering processes as indicated in Table 1, are given as a guideline
to select the severities for the wetting and resistance tests against the specified soldering
heat:
– 10 – IEC 60068-2-58:2015 © IEC 2015
Table 1 – Grouping of soldering processes and typical test severities – Overview
1 2 3 4
a
Process temperature group
Low Medium Medium-high High
Typical solder alloy group Sn-Bi Sn-Pb Sn-Ag-Cu Sn-Cu
c
Typical Flow – 235 °C to 250 °C 250 °C to 260 °C
250 °C to 260 °C
process
Reflow
170 °C to 210 °C 210 °C to 240 °C 235 °C to 250 °C –
temperature
Test
Test property Temperature / Duration
method
Solder bath Solderability
175 °C / 3 s 235 °C / 2 s 245 °C / 3 s 250 °C / 3 s
(6.5)
Resistance to 260 °C / 5 s 260 °C / 5 s
soldering heat 230 °C / 10 s 260 °C / 10 s
260 °C / 10 s 260 °C / 10 s
(7.5)
Dewetting (8.2) 260 °C / 5 s
– – –
260 °C / 10 s
Resistance to
dissolution of
– 260 °C / 30 s
metallization
(8.2)
b
Reflow
Solderability
170 °C / 10 s 215 °C / 10 s 235 °C / 10 s –
(6.6)
Resistance to 230 °C / 30 s
soldering heat
245 °C / 30 s
(7.6)
– 235 °C / 20 s –
Dewetting (8.2) 250 °C / 30 s
260 °C / 30 s
a
Refer to the appropriate subclauses for the detailed test conditions.
b
Measured at the solder joint.
c
255 °C to 265 °C may be an applicable soldering temperature range for boards with high thermal demand.

The following statements shall be applied in Table 1;
– Flow soldering applies to both wave soldering and dip soldering.
– Typical process temperatures for flow soldering are identical to the solder temperature.
Typical process temperatures for reflow soldering are the terminal and top surface
temperature of the SMDs.
– The basic solder alloys listed in Table 1 present tin-lead solder and compositions that are
currently preferred for lead-free soldering processes. However, other solder alloys when
matching with the specified group should not be excluded.
5 Test equipment
5.1 Solder bath
As given in IEC 60068-2-20:2008, 5.2.1, the solder bath shall be not less than 40 mm in depth
and not less than 300 ml in volume.
In case of high thermal capacity components, the volume of the solder bath shall be given by
the relevant specification.
The material of the solder bath container shall be resistant to the liquid solder alloy.
5.2 Reflow equipment
As long as the test conditions are fulfilled, any reflow equipment may be used. The following
two methods are preferred:
IEC 60068-2-58:2015 © IEC 2015 – 11 –
a) forced gas convection;
b) vapour phase.
NOTE 1 Forced gas convection is preferred, including infrared assistance.
NOTE 2 In case of vapour phase soldering, a specific vapour creating liquid is necessary for each test
temperature.
6 Test Td : Solderability of terminations
6.1 Object and general description of the test
Test Td provides two different test methods to determine the solderability of the metallized
end cap terminations and metallic terminations which meets the applicable solder joint
requirements of IEC 61191-2 using each of the soldering methods specified in IEC 61760-1.
– Method 1: Solder bath
– Method 2: Reflow
The test method to be used shall be prescribed in the relevant specification.
NOTE 1 The solder bath method is the one that simulates most closely the soldering procedures of flow soldering
and similar soldering processes where the heat is applied directly through conduction from a molten solder.
NOTE 2 The reflow method is the one that simulates most closely the soldering procedures of reflow soldering
processes, like forced gas convection or vapour phase, where the heat is applied by gas convection or vapour
condensation.
6.2 Specimen preparation
The surface to be tested shall be in the "as received" condition and needs to be shielded from
any kind of contamination, e.g. it shall not be subsequently touched by fingers.
The specimens shall not be cleaned prior to the application of a solderability test. If required
by the relevant specification, the specimens may be degreased by immersion in a neutral
organic solvent at room temperature.
6.3 Accelerated ageing
When accelerated ageing is prescribed by the relevant specification, one of the methods of
IEC 60068-2-20:2008, 4.1.4 shall be used.
6.4 Initial measurements
The specimens shall be visually examined and, if required by the relevant specification,
electrically and mechanically checked.
6.5 Method 1: Solder bath
6.5.1 Solder bath
See 5.1.
6.5.2 Solder and flux
The solder alloy shall be selected from Table 2, unless otherwise prescribed by the relevant
specification.
– 12 – IEC 60068-2-58:2015 © IEC 2015
Table 2 – Solder alloy and flux for test Td
a
Process temperature group Solder alloy and flux
b
Sn42Bi58
2 Sn60Pb40A or Sn63Pb37A
3 Sn96,5Ag3Cu,5
4 Sn99,3Cu,7
a
Solder alloy designations and tolerance of composition according to
IEC 61190-1-3:2007 and Amendment 1:2010, Annex B.
b
Activated with 0,2 % chloride.

The flux shall consist of 25 % mass fraction of colophony in 75 % mass fraction of 2-propanol
(isopropanol) or ethyl alcohol (as specified in IEC 60068-2-20:2008, Annex B). Preferably the
flux activity should conform with the “low (<0,01)” level L0, corresponding to a halide mass
fraction of <0,01 % (Cl, Br, F) (see IEC 61190-1-1).
If non-activated flux is inappropriate, the relevant specification may prescribe the use of the
above flux with the addition of diethylammonium chloride (analytical reagent grade) of a mass
fraction of 0,2 % or 0,5 % chloride (expressed as free chlorine based on the colophony
content), see Table 2.
6.5.3 Test procedure and conditions
6.5.3.1 Specimen
A specimen shall not be used for more than one test.
6.5.3.2 Clamping
The specimen shall be placed in a stainless steel clip as shown in Figure 1, where the cross
sectional area of that clip shall not exceed the smallest cross sectional area of the specimen,
unless otherwise prescribed by the relevant specification. No part of the clip jaws shall make
contact with the areas to be examined. The specimen shall remain in the clip while being
fluxed and dipped in the solder.
NOTE A clip with a thermal capacity of its dipped part significantly exceeding the thermal capacity of the
specimen may lead to a decrease of the local bath temperature next to the specimen and thereby to an increase of
the effective severity of this test.
6.5.3.3 Fluxing
The specimen shall be completely immersed in flux and withdrawn slowly, unless otherwise
prescribed by the relevant specification. Any excess flux shall be removed by contact with
absorbent paper.
6.5.3.4 Solder immersion
The specified duration and temperature shall be applied immediately prior to the immersion of
the specimen in the solder bath, unless otherwise prescribed by the relevant specification.
The oxide film on the solder bath shall be skimmed off immediately before immersion.
The immersion and withdrawal speed shall be in the range of 20 mm/s to 25 mm/s.

IEC 60068-2-58:2015 © IEC 2015 – 13 –
3 3 3
View of the surface to be examined
IEC
Key
1 Clip
2 Specimen
3 Solder
The immersion method may not be applicable for high thermal capacity components. The method to be applied for
such components shall be given in the relevant specification.
Figure 1 – Examples of immersion attitudes
Two attitudes of immersion are standardized:
Attitude A: For most specimens, the areas to be examined shall be immersed not less than
2 mm below the solder meniscus (but not to a greater depth than necessary; see
Figure 1) with the seating plane vertical.
Attitude B: For certain specimens (see B.3.4), the specimen may be floated on the solder.
Attitude A shall be applied, if the relevant specification does not prescribe an attitude to be
used.
6.5.3.5 Test conditions
The duration and temperature of immersion shall be selected from Table 3, unless otherwise
prescribed by the relevant specification.

– 14 – IEC 60068-2-58:2015 © IEC 2015
Table 3 – Solderability – Test conditions and severity, solder bath method
a
Group Alloy name Test conditions and severity
Sn42Bi58
(175 ± 3) °C (3 ± 0,5) s
(activated flux, 0,2 % chloride)
(215 ± 3) °C (3 ± 0,2) s
Sn60Pb40A or
Sn63Pb37A
(235 ± 3) °C (2 ± 0,2) s
3 Sn96,5Ag3Cu,5 (245 ± 3) °C (3 ± 0,3) s
4 Sn99,3Cu,7 (250 ± 3) °C (3 ± 0,3) s
a
For components having a high thermal capacity the relevant specification may prescribe an extension of the
immersion time up to (10 ± 1) s.

6.6 Method 2: Reflow
6.6.1 Reflow equipment
See 5.2.
6.6.2 Solder paste
Solder paste shall be as in Table 4, unless otherwise prescribed by the relevant specification.
Table 4 – Solder paste specification
b
Nominal metal content,
Flux classification
a c
Group mass fraction
Alloy name Powder size type
IEC ISO
%
1 Sn42Bi58 ROL0 1.1.1 3 90
2 Sn60Pb40A or
ROL0 1.1.1 3 90
Sn63Pb37A
3 Sn96,5Ag3Cu,5 ROL0 1.1.1 3 88
4 – – – –
a
Solder alloy designations and tolerance of composition according to IEC 61190-1-3:2007 and Amendment
1:2010, Annex B.
b
Refer to IEC 61190-1-1 or ISO 9454-2 for details.
c
Refer to IEC 61190-1-2:2014, Table 2. Any other powder size should be prescribed in the relevant

specification.
6.6.3 Test substrates
The test substrate shall consist of an unmetallized and non-wettable (no tracks or lands)
piece of ceramic
...