IEC 60068-2-58:2015

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)

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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

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

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
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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6) All users should ensure that they have the latest edition of this publication.
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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.
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

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:
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.

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 (alumina 90 % to 98 %) or epoxide woven E-glass laminated circuit board as
defined, for example, in IEC 61249-2-22 or IEC 61249-2-35.
For the solderability test, the test substrate should not have solder lands, as a visual
examination of the bottom side of the termination/electrode is required. See Annex A.
Dimensional details and the number of sample(s) to be tested shall be given in the relevant
specification.
6.6.4 Test procedure
6.6.4.1 Specimens
A specimen shall not be used for more than one test.
6.6.4.2 Application of solder paste
The solder paste shall be applied to the test substrate by screen or stencil printing,
dispensing or pin transfer.
The area (size) to be printed, and thus the amount of solder paste deposit, shall be specified
in the relevant specification. When solder paste is applied by dispensing or pin transfer, the
volume shall be adjusted so that a comparable solder volume can be achieved.
NOTE The thickness of the solder deposit is in the range from 60 µm to 250 µm.
6.6.4.3 Placement of specimens
After printing, the terminations of the specimen shall be placed on the solder paste. The
placement procedure (for example depth of penetration) shall be prescribed in the relevant
specification.
6.6.5 Reflow temperature profile for Test Td
As a minimum, the following parameters shown in Figure 2 shall be specified for the reflow
temperature profile.
t
T
T − 5 °C
T
c
T
b
T t
1 2
t
a
t
Time
IEC
Key
T Minimum preheating temperature
T Maximum preheating temperature

T Liquidus temperature
T Peak temperature
t Preheating duration
t Time above liquidus temperature

t Time above (T – 5 °C)
3 4
t Time to T
4 4
a The temperature gradient of the increasing slope shall not exceed 3 K/s.
b Preheat area.
c The temperature gradient of the decreasing slope shall not exceed 6 K/s.
Figure 2 – Reflow temperature profile for solderability
Temperature
– 16 – IEC 60068-2-58:2015 © IEC 2015
The temperature shall be measured at the specimen termination, unless otherwise prescribed
by the relevant specification.
6.6.6 Test conditions
The parameters for the temperature profile shall be selected from Table 5, unless otherwise
prescribed by the relevant specification.
Table 5 – Solderability – Test conditions – Method 2: Reflow
a b
T T t T t
T t
1 2 1 3 2
4 3
Group Solder alloy
°C °C s °C s °C s
1 Sn42Bi58 100 ± 5 130 ± 5 60 to 120 138 40 ± 5 170 10
2 Sn63Pb37A
100 150 60
...

IEC 60068-2-58 ®
Edition 4.1 2017-07
CONSOLIDATED VERSION
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)

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IEC 60068-2-58 ®
Edition 4.1 2017-07
CONSOLIDATED VERSION
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 978-2-8322-4570-5

IEC 60068-2-58 ®
Edition 4.1 2017-07
CONSOLIDATED VERSION
REDLINE VERSION
VERSION REDLINE
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)

– 2 – IEC 60068-2-58:2015+AMD1:2017 CSV
© IEC 2017
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 2017
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 . 25
9.3.4 Resistance to dissolution of metallization. 25
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 . 26
Annex A (normative) Criteria for visual examination . 27
A.1 Evaluation of wetting . 27
A.1.1 General . 27
A.1.2 Evaluation of Criteria for wetting . 27
A.1.3 Evaluation of method 2 (Td ) Additional criteria for wetting, method 2 . 28
A.2 Evaluation of dewetting, method 2 (Td ) . 29
Annex B (informative) Guidance . 31
B.1 General . 31
B.2 Limitations . 31
B.3 Choice of severity . 31
B.3.1 Test Td : Solderability by solder bath method . 31
B.3.2 Test Td : Resistance to soldering heat – Solder bath method . 32
B.3.3 Test Td : Resistance to soldering heat –Reflow method . 32
B.3.4 Immersion attitude . 33
B.3.5 Test Td : Dewetting and resistance to dissolution of metallization for
30 s at 260 °C . 33
Annex C (normative) Application of the test methods to through hole reflow soldering
components (THR) . 34
C.1 Solderability . 34
C.2 Resistance to soldering heat . 34
C.3 Dewetting . 34
C.4 Criteria for evaluation . 34
Annex X (informative) Cross reference for references to the prior revision of this
specification. 35
Bibliography . 37

– 4 – IEC 60068-2-58:2015+AMD1:2017 CSV
© IEC 2017
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
Figure A.2 – Evaluation of dewetting . 30

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. 32
Table C.1 – Test conditions for solderability test . 34

© IEC 2017
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
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This consolidated version of the official IEC Standard and its amendment has been
prepared for user convenience.
IEC 60068-2-58 edition 4.1 contains the fourth edition (2015-03) [documents
91/1222/FDIS and 91/1250/RVD] and its amendment 1 (2017-07) [documents
91/1445/FDIS and 91/1451/RVD].
In this Redline version, a vertical line in the margin shows where the technical content
is modified by amendment 1. Additions are in green text, deletions are in strikethrough
red text. A separate Final version with all changes accepted is available in this
publication.
– 6 – IEC 60068-2-58:2015+AMD1:2017 CSV
© IEC 2017
International Standard IEC 60068-2-58 has been prepared by IEC technical committee 91:
Electronics assembly technology.
This fourth edition 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;
– implementation of guidance for the choice of a test severity in Clause B.3.
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 the base publication and its amendment will
remain unchanged until the stability date indicated on the IEC web site under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
© IEC 2017
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 document provides procedures for determining the solderability, resistance to
dissolution of metallization 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+AMD1:2017 CSV
© IEC 2017
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 stress 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 2017
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+AMD1:2017 CSV
© IEC 2017
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:
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g) forced gas convection;
h) 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+AMD1:2017 CSV
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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
If the preheating is prescribed by the relevant specification, 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.

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3 3
View of the surface to be examined
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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+AMD1:2017 CSV
© IEC 2017
Table 3 – Solderability – Test conditions and severity, solder bath method
a
Group Alloy name Test conditions and severity
Sn42Bi58
1 (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 Alloy name Powder size type mass fraction
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 (alumina 90 % to 98 %) or epoxide woven E-glass laminated circuit board as
defined, for example, in IEC 61249-2-22 or IEC 61249-2-35.
For the solderability test, the test substrate should not have solder lands, as a visual
examination of the bottom side of the termination/electrode is required. See Annex A.
Dimensional details and the number of sample(s) to be tested shall be given in the relevant
specification.
6.6.4 Test procedure
6.6.4.1 Specimens
A specimen shall not be used for more than one test.
6.6.4.2 Application of solder paste
The solder paste shall be applied to the test substrate by screen or stencil printing,
dispensing or pin transfer.
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The area (size) to be printed, and thus the amount of solder paste deposit, shall be specified
in the relevant specification. When solder paste is applied by dispensing or pin transfer, the
volume shall be adjusted so that a comparable solder volume can be achieved.
NOTE The thickness of the solder deposit is in the range from 60 µm to 250 µm.
6.6.4.3 Placement of specimens
After printing, the terminations of the specimen shall be placed on the solder paste. The
placement procedure (for example depth of penetration) shall be prescribed in the relevant
specification.
6.6.5 Reflow temperature profile for Test Td
As a minimum, the following parameters shown in Figure 2 shall be specified for the reflow
temperature profile.
t
T
T − 5 °C
T
c
T
b
T t
1 2
t
a
t
Time
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Key
T Minimum preheating temperature
T Maximum preheating temperature

T Liquidus temperature
T Peak temperature
t Preheating duration
t Time above liquidus temperature

t Time above (T – 5 °C
...