IEC 61189-5-3:2015

IEC 61189-5-3 ®
Edition 1.0 2015-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Test methods for electrical materials, printed boards and other interconnection
structures and assemblies –
Part 5-3: General test methods for materials and assemblies – Soldering paste
for printed board assemblies
Méthodes d'essai pour les matériaux électriques, les cartes imprimées et autres
structures d'interconnexion et ensembles –
Partie 5-3: Méthodes d'essai générales pour les matériaux et les assemblages –
Pâte de brasage pour les assemblages de cartes imprimées
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 Central Office Tel.: +41 22 919 02 11
3, rue de Varembé Fax: +41 22 919 03 00
CH-1211 Geneva 20 info@iec.ch
Switzerland www.iec.ch
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 corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing more than 30 000 terms and
Technical Specifications, Technical Reports and other definitions in English and French, with equivalent terms in 15
documents. Available for PC, Mac OS, Android Tablets and additional languages. Also known as the International
iPad. Electrotechnical Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a More than 60 000 electrotechnical terminology entries in
variety of criteria (reference number, text, technical English and French extracted from the Terms and Definitions
committee,…). It also gives information on projects, replaced clause of IEC publications issued since 2002. Some entries
and withdrawn publications. have been collected from earlier publications of IEC TC 37,

77, 86 and CISPR.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: csc@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.

Catalogue IEC - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
Application autonome pour consulter tous les renseignements
Le premier dictionnaire en ligne de termes électroniques et
bibliographiques sur les Normes internationales,
électriques. Il contient plus de 30 000 termes et définitions en
Spécifications techniques, Rapports techniques et autres
anglais et en français, ainsi que les termes équivalents dans
documents de l'IEC. Disponible pour PC, Mac OS, tablettes
15 langues additionnelles. Egalement appelé Vocabulaire
Android et iPad.
Electrotechnique International (IEV) en ligne.

Recherche de publications IEC - www.iec.ch/searchpub
Glossaire IEC - std.iec.ch/glossary
Plus de 60 000 entrées terminologiques électrotechniques, en
La recherche avancée permet de trouver des publications IEC
en utilisant différents critères (numéro de référence, texte, anglais et en français, extraites des articles Termes et
comité d’études,…). Elle donne aussi des informations sur les Définitions des publications IEC parues depuis 2002. Plus
projets et les publications remplacées ou retirées. certaines entrées antérieures extraites des publications des

CE 37, 77, 86 et CISPR de l'IEC.
IEC Just Published - webstore.iec.ch/justpublished

Service Clients - webstore.iec.ch/csc
Restez informé sur les nouvelles publications IEC. Just
Published détaille les nouvelles publications parues. Si vous désirez nous donner des commentaires sur cette
Disponible en ligne et aussi une fois par mois par email. publication ou si vous avez des questions contactez-nous:
csc@iec.ch.
IEC 61189-5-3 ®
Edition 1.0 2015-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Test methods for electrical materials, printed boards and other interconnection

structures and assemblies –
Part 5-3: General test methods for materials and assemblies – Soldering paste

for printed board assemblies
Méthodes d'essai pour les matériaux électriques, les cartes imprimées et autres

structures d'interconnexion et ensembles –

Partie 5-3: Méthodes d'essai générales pour les matériaux et les assemblages –

Pâte de brasage pour les assemblages de cartes imprimées

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.180 ISBN 978-2-8322-1998-0

– 2 – IEC 61189-5-3:2015 © IEC 2015
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Accuracy, precision and resolution . 8
3.1 General . 8
3.2 Accuracy . 9
3.3 Precision . 9
3.4 Resolution . 10
3.5 Report. 10
3.6 Student’s t distribution . 10
3.7 Suggested uncertainty limits . 11
4 X: Miscellaneous test methods . 12
4.1 Test 5-3X01: Paste flux viscosity – T-Bar spindle method . 12
4.1.1 Object . 12
4.1.2 Test specimen . 12
4.1.3 Apparatus and reagents . 12
4.1.4 Procedure . 12
4.1.5 Safety notes . 12
4.2 Test 5-3X02: Spread test, extracted solder flux, paste flux and solder paste . 12
4.2.1 Object . 12
4.2.2 Method A . 13
4.2.3 Method B . 14
4.2.4 Additional information . 15
4.3 Test 5-3X03: Solder paste viscosity – T-Bar spin spindle method (applicable
for 300 Pa·s to 1 600 Pa·s) . 15
4.3.1 Object . 15
4.3.2 Test specimen . 15
4.3.3 Equipment/apparatus . 15
4.3.4 Procedure . 16
4.3.5 Evaluation . 16
4.3.6 Additional information . 16
4.4 Test 5-3X04: Solder paste viscosity – T-Bar spindle method (applicable to
300 Pa·s) . 16
4.4.1 Object . 16
4.4.2 Test specimen . 17
4.4.3 Equipment/apparatus . 17
4.4.4 Procedure . 17
4.4.5 Evaluation . 17
4.4.6 Additional information . 17
4.5 Test 5-3X05: Solder paste viscosity – Spiral pump method (applicable for
300 Pa·s to 1 600 Pa·s) . 18
4.5.1 Object . 18
4.5.2 Test specimen . 18
4.5.3 Equipment/apparatus . 18
4.5.4 Procedure . 18

4.5.5 Evaluation . 18
4.5.6 Additional information . 18
4.6 Test 5-3X06: Solder paste viscosity – Spiral pump method (applicable to 300
Pa·s) . 19
4.6.1 Object . 19
4.6.2 Test specimen . 19
4.6.3 Equipment/apparatus . 19
4.6.4 Procedure . 19
4.6.5 Evaluation . 19
4.6.6 Additional information . 19
4.7 Test 5-3X07: Solder paste – Slump test . 20
4.7.1 Object . 20
4.7.2 Test specimen . 20
4.7.3 Equipment/apparatus . 20
4.7.4 Procedure . 20
4.7.5 Evaluation . 22
4.8 Test 5-3X08: Solder paste − Solder ball test . 22
4.8.1 Object . 22
4.8.2 Test specimen . 23
4.8.3 Equipment/apparatus . 23
4.8.4 Procedure . 23
4.8.5 Evaluation . 24
4.9 Test 5-3X09: Solder paste − Tack test . 25
4.9.1 Object . 25
4.9.2 Method A . 25
4.9.3 Method B . 26
4.9.4 Test equipment sources . 27
4.10 Test 5-3X10: Solder paste − Wetting test . 27
4.10.1 Object . 27
4.10.2 Test specimen . 27
4.10.3 Equipment/materials/apparatus. 27
4.10.4 Procedure . 27
4.10.5 Evaluation . 28
4.11 Test 5-3X11: Determination of solder powder particle size distribution –
Screen method for types 1-4 . 28
4.11.1 Object . 28
4.11.2 Test specimen . 28
4.11.3 Equipment/apparatus . 28
4.11.4 Procedure . 28
4.12 Test 5-3X12: Solder powder particle size distribution – Measuring
microscope method . 30
4.12.1 Object . 30
4.12.2 Test specimen . 30
4.12.3 Equipment/apparatus . 30
4.12.4 Procedure . 30
4.13 Test 5-3X13: Solder powder particle size distribution – Optical image
analyser method . 31
4.13.1 Object . 31
4.13.2 Test specimen . 31
4.13.3 Equipment/apparatus . 31

– 4 – IEC 61189-5-3:2015 © IEC 2015
4.13.4 Procedure . 32
4.14 Test 5-3X14: Solder powder particle size distribution – Measuring laser
diffraction method . 33
4.14.1 Object . 33
4.14.2 Test specimen . 33
4.14.3 Equipment/apparatus . 33
4.14.4 Preparation . 34
4.14.5 Test procedure . 34
4.14.6 Test . 34
4.14.7 Evaluation . 34
4.15 Test 5-3X15: Determination of maximum solder powder particle size . 35
4.15.1 Object . 35
4.15.2 Test specimen . 35
4.15.3 Evaluation . 35
4.16 Test 5-3X16: Solder paste metal content by weight . 36
4.16.1 Object . 36
4.16.2 Test specimen . 36
4.16.3 Equipment/apparatus . 36
4.16.4 Procedure . 36
Annex A (informative) Typical comparison of particle size distributions between laser
diffraction method and screen method . 38
Bibliography . 39

Figure 1 – Slump test stencil thickness, 0,20 mm . 21
Figure 2 – Slump test stencil thickness, 0,10 mm . 21
Figure 3 – Solder-ball test evaluation . 24
Figure 4 – Solder wetting examples . 28
Figure A.1 – Typical comparison between laser diffraction and sieving . 38

Table 1 – Student’s t distribution . 11
Table 2 – Typical spread areas defined in mm . 13
Table 3 – Example of a test report – Stencil thickness, 0,2 mm . 22
Table 4 – Example of a test report – Stencil thickness, 0,1 mm . 22
Table 5 – Screen opening . 29
Table 6 – Portions of particle sizes by weight % – nominal values . 30
Table 7 – Powder particle size distribution record . 30
Table 8 – Powder particle size distribution record . 31
Table 9 – Powder particle size distribution record (optical analysis) . 33
Table 10 – Powder particle size distribution record . 34
Table 11 – Acceptance of powders by particle sizes . 36
Table 12 – Example of a test report on solder paste . 37

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
TEST METHODS FOR ELECTRICAL MATERIALS,
PRINTED BOARDS AND OTHER INTERCONNECTION
STRUCTURES AND ASSEMBLIES –
Part 5-3: General test methods for materials and assemblies –
Soldering paste for printed board assemblies

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 61189-5-3 has been prepared by IEC technical committee 91:
Electronics assembly technology.
The text of this standard is based on the following documents:
FDIS Report on voting
91/1211/FDIS 91/1224/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.

– 6 – IEC 61189-5-3:2015 © IEC 2015
This International Standard is used in conjunction with IEC 61189-1:1997, IEC 61189-2:2006,
IEC 61189-3:2007.
A list of all parts in the IEC 61189 series, published under the general title Test methods for
electrical materials, printed boards and other interconnection structures and assemblies, 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.
INTRODUCTION
IEC 61189 relates to test methods for materials or component robustness for printed board
assemblies, irrespective of their method of manufacture.
The standard is divided into separate parts, covering information for the designer and the test
methodology engineer or technician. Each part has a specific focus; methods are grouped
according to their application and numbered sequentially as they are developed and released.
In some instances test methods developed by other TCs (for example, TC 104) have been
reproduced from existing IEC standards in order to provide the reader with a comprehensive
set of test methods. When this situation occurs, it will be noted on the specific test method; if
the test method is reproduced with minor revision, those paragraphs that are different are
identified.
This part of IEC 61189 contains test methods for evaluating robustness of materials or
components for printed board assemblies. The methods are self-contained, with sufficient
detail and description so as to achieve uniformity and reproducibility in the procedures and
test methodologies.
The tests shown in this standard are grouped according to the following principles:
P: preparation/conditioning methods
V: visual test methods
D: dimensional test methods
C: chemical test methods
M: mechanical test methods
E: electrical test methods
N: environmental test methods
X: miscellaneous test methods
To facilitate reference to the tests, to retain consistency of presentation, and to provide for
future expansion, each test is identified by a number (assigned sequentially) added to the
prefix (group code) letter showing the group to which the test method belongs.
The test method numbers have no significance with respect to an eventual test sequence; that
responsibility rests with the relevant specification that calls for the method being performed.
The relevant specification, in most instances, also describes pass/fail criteria.
The letter and number combinations are for reference purposes to be used by the relevant
specification. Thus "5-3X01" represents the first chemical test method described in
IEC 61189-5-3.
In short, in this example, 5-3 is the number of the part of IEC 61189, X is the group of
methods, and 01 is the test number.

– 8 – IEC 61189-5-3:2015 © IEC 2015
TEST METHODS FOR ELECTRICAL MATERIALS,
PRINTED BOARDS AND OTHER INTERCONNECTION
STRUCTURES AND ASSEMBLIES –
Part 5-3: General test methods for materials and assemblies –
Soldering paste for printed board assemblies

1 Scope
This part of IEC 61189 is a catalogue of test methods representing methodologies and
procedures that can be applied to test printed board assemblies.
This part of IEC 61189 focuses on test methods for soldering paste based on the existing
IEC 61189-5 and IEC 61189-6. In addition, it includes test methods of soldering paste for lead
free soldering.
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 61189-5, Test methods for electrical materials, interconnection structures and
assemblies – Part 5: Test methods for printed board assemblies
IEC 61189-6, Test methods for electrical materials, interconnection structures and
assemblies – Part 6: Test methods for materials used in manufacturing electronic assemblies
IEC 61190-1-2:2014, Attachment materials for electronic assembly – Part 1-2: Requirements
for soldering pastes for high-quality interconnections in electronics assembly
IEC 61190-1-3, Attachment materials for electronic assembly – Part 1-3: Requirements for
electronic grade solder alloys and fluxed and non-fluxed solid solders for electronic soldering
applications
3 Accuracy, precision and resolution
3.1 General
Errors and uncertainties are inherent in all measurement processes. The information given
below enables valid estimates of the amount of error and uncertainty to be taken into account.
Test data serve a number of purposes which include
– monitoring of a process;
– enhancing of confidence in quality conformance;
– arbitration between customer and supplier.
In any of these circumstances, it is essential that confidence can be placed upon the test data
in terms of
– accuracy: calibration of the test instruments and/or system;
– precision: the repeatability and uncertainty of the measurement;
– resolution: the suitability of the test instrument and/or system.
3.2 Accuracy
The regime by which routine calibration of the test equipment is undertaken shall be clearly
stated in the quality documentation of the supplier or agency conducting the test and should
meet the requirements of ISO 9001.
The calibration shall be conducted by an agency having accreditation to a national or
international measurement standard institute. There should be an uninterrupted chain of
calibration to a national or international standard.
Where calibration to a national or international standard is not possible, round-robin
techniques may be used and documented to enhance confidence in measurement accuracy.
The calibration interval shall normally be one year. Equipment consistently found to be
outside acceptable limits of accuracy shall be subject to shortened calibration intervals.
Equipment consistently found to be well within acceptable limits may be subject to relaxed
calibration intervals.
A record of the calibration and maintenance history shall be maintained for each instrument.
These records should state the uncertainty of the calibration technique (in ± % deviation) in
order that uncertainties of measurement can be aggregated and determined.
A procedure shall be implemented to resolve any situation where an instrument is found to be
outside calibration limits.
3.3 Precision
The uncertainty budget of any measurement technique is made up of both systematic and
random uncertainties. All estimates shall be based upon a single confidence level, the
minimum being 95 %.
Systematic uncertainties are usually the predominant contributor and will include all
uncertainties not subject to random fluctuation. These include
– calibration uncertainties;
– errors due to the use of an instrument under conditions which differ from those under
which it was calibrated;
– errors in the graduation of a scale of an analogue meter (scale shape error).
Random uncertainties result from numerous sources but can be deduced from repeated
measurement of a standard item. Therefore, it is not necessary to isolate the individual
contributions. These may include
– random fluctuations such as those due to the variation of an influence parameter.
Typically, changes in atmospheric conditions reduce the repeatability of a measurement;
– uncertainty in discrimination, such as setting a pointer to a fiducial mark or interpolating
between graduations on an analogue scale.
Aggregation of uncertainties: Geometric addition (root-sum-square) of uncertainties may be
used in most cases. Interpolation error is normally added separately and may be accepted as
being 20 % of the difference between the finest graduations of the scale of the instrument.
2 2
U = ± (U + U ) + U
t s r i
– 10 – IEC 61189-5-3:2015 © IEC 2015
where
U is the total uncertainty;
t
U is the systematic uncertainty;
s
U is the random uncertainty;
r
U is the interpolation error.
i
Determination of random uncertainties: Random uncertainty can be determined by repeated
measurement of a parameter and subsequent statistical manipulation of the measured data.
The technique assumes that the data exhibits a normal (Gaussian) distribution.
t ×σ
U =
r
n
where
U is the random uncertainty;
r
n is the sample size;
t is the percentage point of the t distribution as shown in Table 1;
σ is the standard deviation (σ ).
n–1
3.4 Resolution
It is paramount that the test equipment used be capable of sufficient resolution. Measurement
systems used should be capable of resolving 10 % (or better) of the test limit tolerance.
It is accepted that some technologies will place a physical limitation upon resolution (for
example, optical resolution).
3.5 Report
In addition to the requirements detailed in the test specification, the report shall detail
a) the test method used;
b) the identity of the sample(s);
c) the test instrumentation;
d) the specified limit(s);
e) an estimate of measurement uncertainty and resultant working limit(s) for the test;
f) the detailed test results;
g) the test date and operators’ signature.
3.6 Student’s t distribution
Table 1 gives values of the factor t for 95 % and 99 % confidence levels, as a function of the
number of measurements.
Table 1 – Student’s t distribution
Sample t value t value Sample t value t value
size 95 % 99 % size 95 % 99 %
2 12,7 63,7  14 2,16 3,01
3 4,3 9,92  15 2,14 2,98
4 3,18 5,84  16 2,13 2,95
5 2,78 4,6  17 2,12 2,92
6 2,57 4,03  18 2,11 2,9
7 2,45 3,71  19 2,1 2,88
8 2,36 3,5  20 2,09 2,86
9 2,31 3,36  21 2,08 2,83
10 2,26 3,25  22 2,075 2,82
11 2,23 3,17  23 2,07 2,81
12 2,2 3,11  24 2,065 2,8
13 2,18 3,05  25 2,06 2,79

3.7 Suggested uncertainty limits
The following target uncertainties are suggested:
a) Voltage < 1 kV: ± 1,5 %
b) Voltage > 1 kV: ± 2,5 %
c) Current < 20 A: ± 1,5 %
d) Current > 20 A: ± 2,5 %
Resistance
e) Earth and continuity: ± 10 %
f) Insulation: ± 10 %
g) Frequency: ± 0,2 %
Time
h) Interval < 60 s: ± 1 s
i) Interval > 60 s: ± 2 %
j) Mass < 10 g: ± 0,5 %
k) Mass 10 g – 100 g: ± 1 %
l) Mass > 100 g: ± 2 %
m) Force: ± 2 %
n) Dimension < 25 mm: ± 0,5 %
o) Dimension > 25 mm: ± 0,1 mm
p) Temperature < 100 °C: ± 1,5 %
q) Temperature > 100 °C: ± 3,5 %
r) Humidity (30 – 75) % RH: ± 5 % RH
Plating thicknesses
s) Backscatter method: ± 10 %
t) Microsection: ± 2 microns
– 12 – IEC 61189-5-3:2015 © IEC 2015
u) Ionic contamination: ± 10 %
4 X: Miscellaneous test methods
4.1 Test 5-3X01: Paste flux viscosity – T-Bar spindle method
4.1.1 Object
This test method is designed to measure the viscosity of paste flux.
4.1.2 Test specimen
The test specimen shall contain enough paste flux to fill a container with a minimum diameter
of 4 cm to a minimum depth of approximately 10 cm.
4.1.3 Apparatus and reagents
a) Viscometer with helipath stand and a T-C spindle (Brookfield RVTD or equivalent).
b) Water bath capable of holding (25 ± 0,5) °C.
c) Stopwatch.
d) Spatula.
4.1.4 Procedure
4.1.4.1 Test
a) Place the container of paste flux in the water bath at (25 ± 0,5) °C.
b) When the medium has attained thermal equilibrium, place the container under the spindle
so that it is at the centre of the surface.
c) Start the Brookfield at 5 r/min and start the helipath stand on descent.
d) Record the value 2 min after the spindle has cut into the top surface of the medium.
Check that the spindle is not touching the bottom of the container.
e) Remove the spindle from the paste flux. Using the spatula, stir the flux vigorously for
(15-20) s and re-measure the viscosity.
4.1.4.2 Expression of results
The viscosities are calculated from the values recorded after 2 min of medium penetration.
Both stirred and unstirred results should be recorded.
4.1.5 Safety notes
Observe all appropriate precautions on material safety data sheets (MSDS) for chemicals
involved in this test method.
4.2 Test 5-3X02: Spread test, extracted solder flux, paste flux and solder paste
4.2.1 Object
This test method gives an indication of activity of solder paste. The test method offers two
methods.
Method A measures the solder spread area.
—————————
Brookfied RVTD is the trade name of a product supplied by Brookfield Engineering Laboratories, Inc. This
information is given for the convenience of users of this document and does not constitute an endorsement by
IEC of the product named. Equivalent products may be used if they can be shown to lead to the same results.

Method B measures the solder spread ratio.
4.2.2 Method A
4.2.2.1 Test specimen
a) For extracted solder flux, a minimum of 10 ml that is furnished in a clean glass container.
b) For paste flux and solder paste flux, 10 ml of the diluted material (35 %).
4.2.2.2 Apparatus and reagents
a) Five replicates of 0,25 mm thick 70/30 brass of a size of approximately 40 mm × 75 mm.
b) Degreased very fine steel wool (for example, #00).
c) Solder wire from Sn63Pb37A, or Sn96.5Ag3Cu0.5, or any other solder alloy wire agreed
between the user and the supplier per IEC 61190-1-3 with a diameter of 1,5 mm.
d) A solder pot not less than 25 mm in depth containing at least 2 kg solder.
4.2.2.3 Test specimen preparation
a) Clean five brass coupons with steel wool.
b) Flatten the brass coupon by bending the opposite sides of the coupon. The two bends
should be parallel to the curve of the metal coil in which the brass was provided in order
to stiffen and flatten the test specimen.
c) Cut a 30 mm length of solid wire solder.
d) Wrap the cut length of solder around a 3 mm mandrel.
e) Cut the coil into individual rings to make a preform of the solder.
4.2.2.4 Test
a) Maintain the solder bath at (260 ± 3) °C for Sn60Pb40, or at (255 ± 3) °C for
Sn96.5Ag3Cu0.5, or at (35 ± 3) °C higher than the liquidus temperature for any other
solder alloy agreed between the user and the supplier .
b) Place the preformed solder on the centre of the test specimen.
c) Place one drop (0,05 ml) of flux on the centre of the preform of the test specimen.
d) Carefully place the coupon on the surface of the solder bath for 15 s.
e) Remove the coupon in a horizontal position and place on a flat surface allowing the
adhered solder to solidify undisturbed.
f) Remove all flux residue with a suitable solvent.
4.2.2.5 Evaluation
Measure the solder spread area by comparing to circles (pre-drawn) with areas similar to
those listed in Table 2. The mean of the spread of all five specimens tested shall be reported.
Record the data and enter it in Table 12.
Table 2 is intended as an aid in defining areas in mm .
Table 2 – Typical spread areas defined in mm
Diameter Area
mm mm
10,00 78,54
10,70 90,00
11,28 100,00
– 14 – IEC 61189-5-3:2015 © IEC 2015
4.2.3 Method B
4.2.3.1 Test specimen
a) Flux may be used from several products. These may be solder paste and paste flux.
b) Solder wire of Sn63Pb37, or Sn96.5Ag3Cu0.5, or any other solder alloy agreed between
the user and the supplier specified in IEC 61190-1-3 shall be wrapped on a ring bar with a
diameter of 3,3 mm.
4.2.3.2 Apparatus and reagents
a) Solder bath: A solder bath with a depth of not less than 30 mm, 100 mm × 150 mm or
more in width and length, provided with a temperature controller up to (50 ± 2) °C above
the liquidus temperature of the tested solder.
b) Dryer: An air convection oven with a temperature controller up to (150 ± 3) °C and
capable of maintaining the temperature.
c) Tongue of other proper tool suitable to lift up the test piece from the solder bath.
d) Scrubber: Suitable to remove easily the oxidized film of solder in the bath.
e) Spatula.
f) Metal mask: Thickness of 2,5 mm with a hole of 6 mm diameter.
g) Micrometer: Measurable to 0,001 mm.
h) Micro syringe or micro pipet: Measurable of 0,05 ml.
i) General experimental device: All-glass device.
j) Abrasive paper (waterproof).
k) Alcohol: Et
...