IEC 60068-2-83:2025

IEC 60068-2-83 ®
Edition 2.0 2025-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Environmental testing –
Part 2-83: Tests – Test Tf: Solderability testing of electronic components for
surface mounting devices (SMD) by the wetting balance method using solder
paste
Essais d’environnement –
Partie 2-83: Essais – Essai Tf: Essai de brasabilité des composants
électroniques pour les composants montés en surface (CMS) par la méthode de
la balance de mouillage utilisant de la pâte à braser
ICS 19.040, 31.190 ISBN 978-2-8327-0449-3

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or
by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either
IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC copyright
or have an enquiry about obtaining additional rights to this publication, please contact the address below or your local
IEC member National Committee for further information.

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

IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - IEC Products & Services Portal - products.iec.ch
webstore.iec.ch/advsearchform Discover our powerful search engine and read freely all the
The advanced search enables to find IEC publications by a publications previews, graphical symbols and the glossary.
variety of criteria (reference number, text, technical With a subscription you will always have access to up to date
committee, …). It also gives information on projects, content tailored to your needs.

replaced and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published containing more than 22 500 terminological entries in English
details all new publications released. Available online and and French, with equivalent terms in 25 additional languages.
once a month by email. Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer
Service Centre: sales@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

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

Recherche de publications IEC -  IEC Products & Services Portal - products.iec.ch
webstore.iec.ch/advsearchform Découvrez notre puissant moteur de recherche et consultez
La recherche avancée permet de trouver des publications gratuitement tous les aperçus des publications, symboles
IEC en utilisant différents critères (numéro de référence, graphiques et le glossaire. Avec un abonnement, vous aurez
texte, comité d’études, …). Elle donne aussi des toujours accès à un contenu à jour adapté à vos besoins.
informations sur les projets et les publications remplacées
ou retirées. Electropedia - www.electropedia.org
Le premier dictionnaire d'électrotechnologie en ligne au
IEC Just Published - webstore.iec.ch/justpublished monde, avec plus de 22 500 articles terminologiques en
Restez informé sur les nouvelles publications IEC. Just anglais et en français, ainsi que les termes équivalents
Published détaille les nouvelles publications parues. dans 25 langues additionnelles. Egalement appelé
Disponible en ligne et une fois par mois par email. Vocabulaire Electrotechnique International (IEV) en ligne.

Service Clients - webstore.iec.ch/csc
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-
nous: sales@iec.ch.
– 2 – IEC 60068-2-83:2025 © IEC 2025
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Test . 8
4.1 General description . 8
4.2 Test methods . 8
5 Preconditioning . 9
6 Preparation . 9
6.1 Solder paste . 9
6.2 Test jig plate . 9
6.3 Specimen holder . 9
7 Quick heating method . 9
7.1 Equipment . 9
7.2 Test jig plate . 10
7.3 Preparation . 11
7.4 Test condition . 12
7.4.1 Test temperature . 12
7.4.2 Feed of solder paste and immersion condition . 12
7.4.3 Immersion and withdrawal conditions for test specimen . 13
7.5 Test procedure . 13
7.6 Presentation of the result . 14
7.7 Characterisation parameter examples . 15
8 Synchronous method . 15
8.1 Equipment . 15
8.2 Test jig plate . 16
8.3 Synchronous fixture . 16
8.4 Preparation . 17
8.5 Test condition . 17
8.5.1 Test temperature . 17
8.5.2 Feed of solder paste and immersion condition . 17
8.5.3 Immersion and withdrawal conditions for the test specimen . 17
8.6 Test procedure . 17
8.7 Presentation of the results . 17
8.8 Characterisation parameter examples . 18
9 Temperature profile method . 19
9.1 Equipment . 19
9.2 Test jig plate . 19
9.3 Preparation . 20
9.4 Test condition . 20
9.4.1 Test temperature . 20
9.4.2 Feed of solder paste and immersion condition . 20
9.4.3 Immersion and withdrawal conditions for test specimen . 21
9.5 Test procedure . 21
9.6 Presentation of the result . 22
9.7 Characterization parameter examples . 23

Annex A (normative) Equipment for the quick heating and synchronous method . 24
A.1 General . 24
A.2 Test equipment . 24
A.2.1 General . 24
A.2.2 Measuring system . 24
A.2.3 Heating system . 24
A.2.4 Lift system . 25
Annex B (informative) Reading of the output data and correction of the result in the
quick heating test . 26
B.1 General . 26
B.2 Reading of the output form in the quick heating test . 26
B.3 Correction to the typical data attained by the quick heating method . 27
Annex C (normative) Test equipment for the temperature profile method . 29
C.1 General . 29
C.2 Test equipment . 29
C.2.1 General . 29
C.2.2 Measuring system . 29
C.2.3 Heating system . 29
C.2.4 Lift system . 29
Annex D (informative) Reading of the output data and correction of the result in the
temperature profile test . 30
D.1 General . 30
D.2 Reading of the output form in the temperature profile test . 30
D.3 Correction to the typical data attained by the temperature profile method . 31
Annex E (informative) Caveats and notes . 33
E.1 General . 33
E.2 Influences . 33
E.2.1 Solder paste . 33
E.2.2 Components . 33
E.3 Interpreting results – Examples . 33
E.3.1 Quick heating method . 33
E.3.2 Synchronous method . 34
E.3.3 Temperature profile method . 35
Bibliography . 37

Figure 1 – Example of quick heating method test equipment . 10
Figure 2 – Example of test jig plate for quick heating and synchronous method . 11
Figure 3 – Example of temperature profile . 12
Figure 4 – Example of application of solder paste to a test jig plate . 13
Figure 5 – Typical output shape of signal in the quick heating method . 14
Figure 6 – Example of synchronous method test equipment . 16
Figure 7 – Example of synchronous fixture. 16
Figure 8 – Typical output shape of signal in the synchronous method . 18
Figure 9 – Example of system for temperature profile method test equipment . 19
Figure 10 – Example of temperature profile. 20
Figure 11 – Example of applying solder paste to a test jig plate . 21
Figure 12 – Typical output shape of signal in the temperature profile method . 23

– 4 – IEC 60068-2-83:2025 © IEC 2025
Figure B.1 – Typical wetting force changes in quick heating method . 27
Figure B.2 – Example of correction of the initial time of wetting (F is larger than
a
0,5 F ) . 28
1,max
Figure B.3 – Example of correction of the initial time of wetting (F is 0,5 F or
a 1,max
less) . 28
Figure D.1 – Typical output forms for the temperature profile test . 31
Figure D.2 – Extruding force (1,1 F or larger) being generated immediately after
max
the beginning of wetting . 32
Figure E.1 – Explanation diagram of test procedure for the quick heating method . 34
Figure E.2 – Explanation diagram of test procedure for synchronous method . 34
Figure E.3 – Wetting force (pull) of solder pastes . 35
Figure E.4 – Explanation diagram of the test procedure for the temperature profile
method . 36

Table 1 – Specification of the test jig plate for quick heating and synchronous method . 10
Table 2 – Recommended test conditions of the quick heating and synchronous method
for rectangular SMD . 13
Table 3 – Specification of the test jig plate of the temperature profile method . 19
Table 4 – Recommended test conditions of the temperature profile method for
rectangular SMD . 21

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ENVIRONMENTAL TESTING –
Part 2-83: Tests – Test Tf: Solderability testing of electronic
components for surface mounting devices (SMD)
by the wetting balance method using solder paste

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 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 60068-2-83 has been prepared by IEC technical committee 91: Electronics assembly
technology. It is an International Standard.
This second edition cancels and replaces the first edition published in 2011. This edition
constitutes a technical revision.
This edition includes the following significant technical change with respect to the previous
edition:
a) Revise Clause 5 to align with that in IEC 60068-2-20:2021.

– 6 – IEC 60068-2-83:2025 © IEC 2025
The text of this International Standard is based on the following documents:
Draft Report on voting
91/2026/FDIS 91/2037/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 60068 series, published under the general title Environmental testing,
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.
ENVIRONMENTAL TESTING –
Part 2-83: Tests – Test Tf: Solderability testing of electronic
components for surface mounting devices (SMD)
by the wetting balance method using solder paste

1 Scope
This part of IEC 60068 provides methods for comparative investigation of the wettability of the
metallic terminations or metallized terminations of SMDs with solder paste.
Data obtained by these methods are not intended to be used as absolute quantitative data for
pass/fail purposes.
NOTE Different solderability test methods for SMD are described in IEC 60068-2-58 and IEC 60068-2-69.
IEC 60068-2-58 specifies visual evaluation using solder bath and reflow method, IEC 60068-2-69 specifies wetting
balance evaluation using solder bath and solder globule method.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60068-1, Environmental testing – Part 1: General and guidance
IEC 60068-2-20:2021, Environmental testing – Part 2-20: Tests – Test Ta and Tb: Test methods
for solderability and resistance to soldering heat of devices with leads
IEC 60068-2-58, 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 60194-2, Printed boards design, manufacture and assembly – Vocabulary – Part 2:
Common usage in electronic technologies as well as printed board and electronic assembly
technologies
IEC 61190-1-3, Attachment materials for electronic assembly – Part 1-3: Requirements for
electronic grade solder alloys and fluxed and non-fluxed solid solder for electronic soldering
applications
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60068-1,
IEC 60068-2-20, IEC 60068-2-58, IEC 60194-2, and IEC 61190-1-3 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp

– 8 – IEC 60068-2-83:2025 © IEC 2025
3.1
wettability
intrinsic property of the termination material to form an alloy with the solder
Note 1 to entry: Wettability depends on the base metal used to produce the termination or, in the case of a plated
termination, the condition and material used to plate the base metal.
[SOURCE: IEC 60068-3-13:2016, 3.1.3]
3.2
wetting balance method
method to measure wetting performance and solderability by measuring vertical force
(difference with surface tension and buoyancy) to the specimen and recording as a function of
time, when the specimen is immersed into molten solder
3.3
zero line
line extended to the time axis of the force experienced by the specimen as indicated by the test
equipment (force sensor) when the specimen is taken out from the molten solder after the end
of the measurement
4 Test
4.1 General description
The specimen is held on a holder suitable to the specimen and is suspended from sensitive
balance. The specimen is immersed into solder paste applied onto the test jig plate, then solder
paste is heated to melt. The resultant of the vertical forces of buoyancy and surface tension
(hereafter, referred to as “acting force”) acting upon the immersed specimen by force sensor
and converted into a signal which is continuously recorded or monitored as a function of time
on recorder.
NOTE The wetting force can be evaluated only for components of the same shape and size. The absolute evaluation
is not achieved by this method.
4.2 Test methods
There are three methods as described below. The choice of the method shall be specified in
the relevant specification.
a) Quick heating method: the wettability of electrodes of a component is evaluated while the
solder paste is melted in a rapid temperature rise. The specimen is immersed in the solder
paste before the temperature rise starts.
b) Synchronous method: the wettability of electrodes of a component is evaluated while the
solder paste is melted due to a rapid temperature rise. The specimen is immersed in the
solder paste when the temperature rise starts.
c) Temperature profile method: solder paste is melted using a similar temperature profile used
in production and the wettability of the electrodes of a component is evaluated.
NOTE 1 This test (Tf) can be applicable to leaded SMD packages. In order to achieve comparable and repeatable
results, test Tf should be done on straight leads.
NOTE 2 Solder paste to be used is agreed between the trading partners.

5 Preconditioning
The test shall be made on the specimens as received and the specimens shall not be
contaminated by fingers and other items, unless otherwise specified in the detailed specification
of the component. The specimen may be immersed in organic solvent at room temperature to
remove possible contamination such as grease attached to the surface if cleaning is required
by the relevant specification. No other method shall be used to clean the specimen. The
specimen thus cleaned may be dried in air.
If required by the relevant specification, one of the preconditioning methods specified in
IEC 60068-2-20:2021, 4.1.1, may be used.
6 Preparation
6.1 Solder paste
Use solder paste that has been stored in a sealed container and stored in a dark environment
and below 10 °C, avoiding exposure to direct sunlight. Before conducting this test, the solder
paste preparation procedure is important.
Expiration date of the solder paste shall be checked before initiating the solder paste
preparation procedure listed below.
a) The solder paste shall be allowed to achieve ambient conditions that shall be nominally
25 °C ± 5 °C and relative humidity of (50 ± 10) % for 8 h or in accordance with the
manufacturer’s data sheet.
b) Open the supply container(s). Remove any internal cover, scrape off the paste adhering to
the lid(s), internal covers, and the container walls. Add this material to the paste in the
supply container(s). Check that the solder paste is not obviously deteriorated nor separated.
c) Using a spatula, stir the paste gently for 1 min to 2 min to homogenize it, ensuring that no
air is introduced.
d) Gently transfer the paste to a test container of sufficient volume, ensuring that no air is
introduced. The solder paste that is once taken out from the container and not used for the
test shall be discarded. The remaining solder paste in the supply container shall be stored
in the original dark and cool environment.
6.2 Test jig plate
Test jig plates shall be stored in a sealed container. Immediately prior to their use, they shall
be cleaned using acid such as dilute hydrochloric acid. A new test jig plate shall be used for
each test. Unused test jig plates shall be discarded and not be returned to the sealed container.
6.3 Specimen holder
The specimen holder is usually contaminated by creeping of flux used in a test. A specimen
holder shall be cleaned using a neutral organic solvent. It is recommended to use ultrasonic
agitation in cleaning.
7 Quick heating method
7.1 Equipment
The equipment used for the quick heating method consists of a measurement, heating and lift
system, as shown in Figure 1. The detailed requirements to the equipment are specified in
Annex A.
– 10 – IEC 60068-2-83:2025 © IEC 2025
The measurement, heating and lift system shall be as follows.
a) The measuring system consists of the force sensor that can measure the force vertically
acted on a specimen, signal transducer and a recorder.
b) The heating system shall be capable of controlling the determined set temperature within
±3 °C.
c) The lift system shall be capable of carrying out immersion and withdrawal of the specimen,
as specified in 7.4.3.
Key
1 specimen 8 housing
2 test jig plate 9 sensor
3 solder paste 10 transducer
4 heating bath 11 recorder
5 lift for test jig plate 12 controller
6 lift for heating bath 13 specimen holder
7 holding jig of a test jig plate

Figure 1 – Example of quick heating method test equipment
7.2 Test jig plate
The test jig plate shall be as specified in Table 1.
Table 1 – Specification of the test jig plate for quick heating and synchronous method
Item Specification of the test jig
material oxygen-free phosphate copper
shape circular indented pan
dimensions (L, W)
less than 30 mm on one side, or less than a total area of 900 mm
thickness (l)
0,3 mm ± 0,03 mm
drawing diameter
9 mm to 10 mm at the bottom,
(D , D )
13 mm to 14 mm at the top
1 2
drawing depth (h) 0,4 mm ± 0,04 mm

Item Specification of the test jig
solder resist diameter
10 mm ± 0,02 mm for the inner diameter,
(D , D )
over 20 mm for the outer diameter
3 4
solder resist thickness 0,035 mm ± 0,01 mm
warp ±0,05 mm (for the longer side for a rectangular shape)

An example of the test jig plate used in the quick heating and synchronous method is shown in
Figure 2.
Key
1 drawing for solder resist D drawing outer diameter
2 solder resist D drawing inner diameter
L, W outer dimension D solder resist inner diameter
l thickness D solder resist outer diameter
h drawing depth
Figure 2 – Example of test jig plate for quick heating and synchronous method
7.3 Preparation
The preparation shall be as specified in Clause 6.

– 12 – IEC 60068-2-83:2025 © IEC 2025
7.4 Test condition
7.4.1 Test temperature
The test jig plate shall be processed using the temperature profile as specified. Figure 3 shows
a typical example.
a a
Symbol
Sn-Ag-Cu (SAC) type Sn-Pb type
T 217 °C 183 °C
T 245 °C ± 3 °C 235 °C ± 3 °C
a
If agreed between the trading partners, the other types of solder paste can be
used.
Key
T liquidous temperarure T test temperature
1 2
T test duration (5 s to15 s) t time from start to T
1 1
t time from start to T
2 2
The test starts at a temperature of 50 °C or below. Time from start to T (t ) shall be 1,5 s or less. Time from start to
1 1
T (t ) shall be 3 s or less. The ramp down rate is not specified.
2 2
Figure 3 – Example of temperature profile
7.4.2 Feed of solder paste and immersion condition
The recommended condition of immersing a specimen into the solder paste is given in Table 2.
For components not specified in Table 2, test conditions shall be specified in the relevant
specification or agreed upon between the trading partners.

Table 2 – Recommended test conditions of the quick heating
and synchronous method for rectangular SMD
Direction of specimen
a b, c
Sizes of specimen Immersion depth immersing into solder
paste
1005 (0402) 0,15 mm Horizontal
1608 (0603)
resistors
2012 (0805) 0,20 mm
3216 (1206)
1005 (0402) 0,15 mm
1608 (0603)
capacitors
2012 (0805) 0,20 mm
3216 (1206)
a
Designation of the size, for example of 1005, means a specimen with a length of 1,0 mm and a width of 0,5 mm.
The dimensions in parentheses are expressed in imperial units.
b
The immersion depths specified in this table are recommended since the buoyancy force varies depending on
the electrode configuration.
c
The immersion depths are the target values.

7.4.3 Immersion and withdrawal conditions for test specimen
The immersion speed of the specimen into the solder paste shall be 0,5 mm/s to 1 mm/s. The
immersion speed of the test jig into the heating bath shall be 1 mm/s to 5 mm/s.
NOTE Since the speed of taking out the specimen from the solder paste and the speed of taking out the test jig
plate from the heating bath after the tests does not affect to the test results, these speeds are arbitrary.
7.5 Test procedure
The test procedure shall be as follows.
a) Apply solder paste to the test jig keeping the surface flat. Figure 4 shows an example.

Key
1 test jig plate
2 solder paste
3 squeegee
4 direction of squeeze movement
Figure 4 – Example of application of solder paste to a test jig plate
b) Mount a specimen into the clip so that the direction specified in 7.4.2 (horizontal) is realized.
The clip shall be centralised to the upper surface of a test jig plate into which the solder
paste has been applied.
c) Adjust the output of the force sensor and the recorder to zero before the test commences.

– 14 – IEC 60068-2-83:2025 © IEC 2025
d) Immerse the specimens as follows.
1) The specimen shall be immersed into the solder paste to the specified depth in 7.4.2.
Then, heat the jig plate to melt the solder paste in accordance with the temperature
profile as specified in Figure 3.
2) The specimen can be required to be immersed into the solder paste to the depth of twice
or more the specified depth, and then the specified depth.
The purpose of this procedure is to apply flux on the portion of the specimen which
corresponds to the immersion depth before heating.
e) Withdraw the specimen from the molten solder paste when measurement is finished.
Recording of the result is completed when the force reaches to a stable state or specified
duration.
7.6 Presentation of the result
The recorder records the force acted to the specimen in the vertical direction. The force acted
upward (pushing force or buoyancy) is recorded as a negative value, and the force acted
downward (wetting force) is recorded as a positive value.
A typical shape of the output signal obtained is shown in Figure 5. The meaning and correction
of the data if different from the shape shown in Figure 5 are given in Annex B.

Key
A reference point to start time measurement (point A is the first positive force peak during the test)
1 1
B instance when the force curve crosses the zero line
C instance when the wetting force reaches 2/3 of the maximum wetting force
D instance when the maximum force is obtained in the measurement
E instance when the specimen is withdrawn after the measurement is completed
F instance when the force reaches stable state after the specimen is withdrawn from the jig plate
t time to start wetting (time duration from point A to point B )
01 1 1
t wetting time (time duration from point B to point C )
11 1 1
F maximum wetting force - maximum force obtained (the value from the zero line) in the measurement
1,max
F final wetting force - force obtained (the value from the zero line) at the end of the test
1,end
Figure 5 – Typical output shape of signal in the quick heating method

7.7 Characterisation parameter examples
The items for the characteristic evaluation should include the following:
a) time to start wetting: t
b) wetting time: t
c) maximum wetting force: F
1,max
d) wetting stability: Sb ; the ratio of the final wetting force (F ) and the maximum wetting
1 1,end
force (F )
1,max
NOTE Wetting stability is calculated as follows: Sb = F /F
1 1,end 1,max
8 Synchronous method
8.1 Equipment
The equipment used for the synchronous method consists of measurement, heating and lift
system as shown in Figure 6. The detailed requirements to the equipment are specified in
Annex A.
The measurement, heating and lift system shall be as follows.
a) The measuring system consists of the force sensor that can measure the force vertically
acted on a specimen, signal transducer and a recorder.
b) The heating system shall be capable of controlling the set temperature specified in 8.5.1.
c) The lift system shall be capable of carrying out immersion and withdrawal of the specimen
as specified in 8.5.3.
d) The synchronous fixturing system shall be capable of permitting the simultaneous immersion
and heating of the specimen as specified in 8.6.

– 16 – IEC 60068-2-83:2025 © IEC 2025

Key
1 specimen 8 mini crucible
2 test jig plate 9 support bars with spring
3 solder paste 10 force sensor
4 heating bath 11 transducer
5 lift 12 recorder
6 Base 13 controller
7 test jig plate holder 14 specimen holder

Figure 6 – Example of synchronous method test equipment
8.2 Test jig plate
The test jig plate shall be as specified in Table 1.
An example of the test jig plate used in the synchronous heating method is shown in Figure 7.
8.3 Synchronous fixture
An example of the synchronous fixture (test jig plate holder and mini crucible) is shown below
in Figure 7.
a) Test jig plate holder b) Mini-crucible

Figure 7 – Example of synchronous fixture

8.4 Preparation
The preparation shall be as specified in Clause 6.
8.5 Test condition
8.5.1 Test temperature
The test jig plate shall be processed using the temperature profile as specified. Figure 3 shows
a typical example.
NOTE Test temperature is the temperature of the test jig plate.
8.5.2 Feed of solder paste and immersion condition
The recommended condition of immersing a specimen into the solder paste is given in Table 2.
For component not specified in Table 2, test conditions shall be specified in the relevant
specification or agreed upon between the trading partners.
8.5.3 Immersion and withdrawal conditions for the test specimen
The immersion speed of the specimen into the solder paste shall be 0,5 mm/s to 1 mm/s, and
that of the mini-crucible shall be 1 mm/s to 5 mm/s.
NOTE Since the speed of taking out the specimen from the solder paste and the speed of taking out the mini-
crucible from the heating bath after the tests do not affect to the test results, these speeds are arbitrary.
8.6 Test procedure
The test procedure shall be as follows.
a) Apply solder paste to the test jig keeping the surface flat. Figure 4 shows an example.
b) Mount a specimen into the clip so that the direction specified in 7.4.2 (horizontal) is realized.
The clip shall be centralised to the upper surface of a test jig plate into which the solder
paste has been applied.
c) Adjust the output of the force sensor and the recorder to zero before the test commences.
d) Mount the jig plate holder onto the supporting bars, adjust the supporting bars’ height just
above the surface of the solder paste close to the bottom edge of the electrode (see
Figure 4). Then, heat the jig plate to melt the solder paste in accordance with the
temperature profile, as specified in Figure 3. The specimen and the solder paste are then
brought into contact synchronously. The immersion speed shall be as specified in 8.5.3.
e) Withdraw the specimen from the molten solder paste when the measurement is finished.
Recording of the result is completed when the force reaches stable state or after a specified
duration.
8.7 Presentation of the results
The recorder records the force acted to the specimen in the vertical direction. The force acted
upward (pushing force or buoyancy) is recorded as a negative value, and the force acted
downward (wetting force) is recorded as a positive value.
A typical shape of the output signal obtained is shown in Figure 8.

– 18 – IEC 60068-2-83:2025 © IEC 2025

Key
A instance when the measurement starts: the specimen is brought in contact with solder paste that is
melting
B instance when the output crosses the zero line: the downward force of the surface tension is exactly
equal to the buoyancy force
C instance when the wetting force reaches 2/3 of the maximum wetting force
D i
...