IEC 61189-5:2006

Test methods for electrical materials, interconnection structures and assemblies - Part 5: Test methods for printed board assemblies

IEC 61189-5:2006 is a catalogue of test methods representing methodologies and procedures that can be applied to test printed board assemblies.

Méthodes d'essai pour les matériaux électriques, les structures d'interconnexion et les ensembles - Partie 5: Méthodes d'essai des assemblages de cartes à circuit imprimé

La CEI 61189-5:2006 est un catalogue de méthodes d'essai représentant les méthodologies et modes opératoires applicables aux assemblages de cartes à circuit imprimé.

General Information

• Status: Withdrawn
• Publication Date: 28-Aug-2006
• Withdrawal Date: 28-Mar-2024
• ICS: 31.180 - Printed circuits and boards
• Technical Committee: TC 91 - Electronics assembly technology
• Drafting Committee: WG 3 - TC 91/WG 3
• Current Stage: WPUB - Publication withdrawn
• Start Date: 02-Apr-2024
• Completion Date: 29-Mar-2024

Relations

• Replaced By: IEC 61189-5-501:2021 - Test methods for electrical materials, printed boards and other interconnection structures and assemblies - Part 5-501: General test methods for materials and assemblies - Surface insulation resistance (SIR) testing of solder fluxes
• Effective Date: 05-Sep-2023
• Replaced By: IEC 61189-5-502:2021 - Test methods for electrical materials, printed board and other interconnection structures and assemblies - Part 5-502: General test methods for materials and assemblies - Surface Insulation Resistance (SIR) testing of assemblies
• Effective Date: 05-Sep-2023

Standards Content (Sample)

INTERNATIONAL IEC
STANDARD 61189-5
First edition
2006-08
Test methods for electrical materials,
interconnection structures and assemblies –
Part 5:
Test methods for printed board assemblies

Reference number
Publication numbering
As from 1 January 1997 all IEC publications are issued with a designation in the

60000 series. For example, IEC 34-1 is now referred to as IEC 60034-1.

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The IEC is now publishing consolidated versions of its publications. For example,

edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the base publication, the

base publication incorporating amendment 1 and the base publication incorporating

amendments 1 and 2.
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INTERNATIONAL IEC
STANDARD 61189-5
First edition
2006-08
Test methods for electrical materials,
interconnection structures and assemblies –
Part 5:
Test methods for printed board assemblies

 IEC 2006  Copyright - all rights reserved
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 the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch
PRICE CODE
Commission Electrotechnique Internationale XB
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue

– 2 – 61189-5  IEC:2006(E)
CONTENTS
FOREWORD.4

INTRODUCTION.6

1 Scope.7

2 Normative references .7

3 Accuracy, precision and resolution .8

3.1 Accuracy .8

3.2 Precision .8
3.3 Resolution .9
3.4 Report .9
3.5 Student’s t distribution.10
3.6 Suggested uncertainty limits.10
4 Catalogue of approved test methods .11
5 P: Preparation/conditioning test methods.11
5.1 Test 5P01: Test-board design guideline.11
5.2 Test 5P02: Standard mounting process for CSP/BGA packages .11
6 V: Visual test methods.11
7 D: Dimensional test methods .11
8 C: Chemical test methods.11
8.1 Test 5C01: Corrosion, flux.11
9 M: Mechanical test methods .14
9.1 Test 5M01: Peel test method for test-board land .14
10 E: Electrical test methods .14
10.1 Test 5E01: Changes of the surface insulation resistance caused by fluxes .14
10.2 Test 5E02: Surface insulation resistance, assemblies .21
11 N Environmental test methods .30
11.1 Test 5N01: Reflow solderability test for soldering joint.30
11.2 Test 5N02: Resistance to reflow solderability of test board.30
11.3 Test 5N03: Solderability test for test-board land .30
12 X Miscellaneous test methods .30
12.1 Test 5X01: Liquid flux activity, wetting balance method .30

12.2 Test 5X02: Paste flux viscosity – T-Bar spindle method.34
12.3 Test 5X03: Spread test, liquid or extracted solder flux, solder paste and
extracted cored wires or preforms .34
12.4 Test 5X04: Solder paste viscosity – T-Bar spin spindle method (applicable to
300 Pa·s to 1,600 Pa·s) .37
12.5 Test 5X05: Solder paste viscosity – T-Bar spindle method (applicable to 300
Pa·s) .40
12.6 Test 5X06: Solder paste viscosity – Spiral pump method (applicable to
300 Pa·s to 1,600 Pa·s) .42
12.7 Test 5X07: Solder paste viscosity – Spiral pump method (applicable to 300
Pa·s) .44
12.8 Test 5X08: Solder paste − Slump test.47
12.9 Test 5X09: Solder paste − Solder ball test.51
12.10 Test 5X10: Solder paste − Tack test .53
12.11 Test 5X11: Solder paste − Wetting test.55

61189-5  IEC:2006(E) – 3 –
12.12 Test 5X12: Flux residues – Tackiness after drying.56

12.13 Test 5X13: Spitting of flux-cored wire solder.58

12.14 Test 5X14: Solder pool test .60

Bibliography.62

Figure 1 – Surface insulation resistance pattern .14

Figure 2 – Connector arrangement.17

Figure 3 – Specimen orientation in test chamber.18

Figure 4 – Test method 5E02.23
Figure 5 – Resistor verification coupon .24
Figure 6 – Resistor verification board with protective cover.25
Figure 7 – Test specimen location with respect to chamber air flow .25
Figure 8 – Wetting balance apparatus.32
Figure 9 – Wetting balance curve.33
Figure 10 – Slump test stencil thickness, 0,20 mm.48
Figure 11 – Slump test stencil thickness, 0,10 mm.49
Figure 12 – Solder ball test evaluation .52
Figure 13 – Solder wetting examples .56
Figure 14 – Test apparatus for spitting test .59

Table 1 – Student’s t distribution.10
Table 2 – Coupons for surface insulation resistance (SIR) testing.16
Table 3 – Qualification test report .21
Table 4 – Suggested test conditions .27
Table 5 – Typical spread areas defined in mm .35
Table 6 – Example of a test report on solder paste .39
Table 7 – Example of a test report on solder paste .41
Table 8 – Example of a test report on solder paste .43
Table 9 – Example of a test report on solder paste .46
Table 10 – Example of a test report – Stencil thickness, 0,2 mm.50
Table 11 – Example of a test report – Stencil thickness, 0,1 mm.50

– 4 – 61189-5  IEC:2006(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION

___________
TEST METHODS FOR ELECTRICAL MATERIALS,

INTERCONNECTION STRUCTURES AND ASSEMBLIES –

Part 5: Test methods 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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
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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 has been prepared by IEC technical committee 91:
Electronic assembly technology.
The text of this standard is based on the following documents:
FDIS Report on voting
91/608/FDIS 91/619/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.

61189-5  IEC:2006(E) – 5 –
This standard is to be used in conjunction with the following parts of IEC 61189:

Part 1: General test methods and methodology

Part 2: Test methods for materials for interconnection structures

Part 3: Test methods for interconnection structures (printed boards)

Part 4: Test methods for electronic components assembling characteristics

Part 6: Test methods for materials used in electronic assemblies

and also the following standard:

IEC 60068: Environmental testing

The list of all the parts of the IEC 61189 series, under the general title Test methods for
electrical materials, 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 maintenance result date indicated on the IEC website 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.
– 6 – 61189-5  IEC:2006(E)
INTRODUCTION
IEC 61189 relates to test methods for printed boards and printed board assemblies, as well as

related materials or component robustness, 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 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 criterion.
The letter and number combinations are for reference purposes to be used by the relevant

specification. Thus "5C01" represents the first chemical test method described in IEC 61189-5.
In short, in this example, 5 is the number of the part of IEC 61189, C is the group of methods,
and 01 is the test number.
A list of all test methods included in this standard, as well as those under consideration, is
given in Annex B. This annex will be reissued whenever new tests are introduced.

61189-5  IEC:2006(E) – 7 –
TEST METHODS FOR ELECTRICAL MATERIALS,

INTERCONNECTION STRUCTURES AND ASSEMBLIES –

Part 5: Test methods 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.
2 Normative references
The following referenced documents are indispensable for the application 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 60068-1:1988, Environmental testing – Part 1: General and guidance
IEC 60068-2-20, Environmental testing – Part 2-20: Tests – Test T:Soldering
IEC 61189-1, Test methods for electrical materials, interconnection structures and assemblies
– Part 1: General test methods and methodology
IEC 61189-3, Test methods for electrical materials, interconnection structures and assemblies
– Part 3: Test methods for interconnection structures (printed boards)
IEC 61189-6, Test methods for electrical materials, interconnection structures and assemblies
– Part 6: Test methods for materials used in manufacturing electronic assemblies
IEC 61190-1-1, Attachment materials for electronic assembly – Part 1-1: Requirements for
soldering fluxes for high-quality interconnections in electronics assembly
IEC 61190-1-2:2002, Attachment materials for electronic assembly – Part 1-2: Requirements
for solder 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
IEC 61249-2-7, Materials for printed boards and other interconnecting structures – Part 2-7:
Reinforced base materials clad and unclad – Epoxide woven E-glass laminated sheet of
defined flammability (vertical burning test), copper-clad
IEC 62137:2004, Environmental and endurance testing - Test methods for surface-mount
boards of area array type packages FBGA, BGA, FLGA, LGA, SON and QFN
ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results – Part 2:
Basic method for the determination of repeatability and reproducibility of a standard
measurement method
ISO 9001, Quality management systems – Requirements

– 8 – 61189-5  IEC:2006(E)
ISO 9455-1, Soft soldering fluxes – Test methods – Part 1: Determination of non-volatile

matter, gravimetric method
ISO 9455-2, Soft soldering fluxes –Test methods – Part 2: Determination of non-volatile

matter, ebulliometric method
3 Accuracy, precision and resolution

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.
3.1 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 shall
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.
3.2 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

61189-5  IEC:2006(E) – 9 –
– 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
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
3.3 Resolution
It is paramount that the test equipment used is 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).
3.4 Report
In addition to 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);
– 10 – 61189-5  IEC:2006(E)
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.

3.5 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

3.6 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 %

61189-5  IEC:2006(E) – 11 –
q) Temperature > 100 °C: ± 3,5 %

r) Humidity (30 – 75) % RH: ± 5 % RH

Plating thicknesses
s) Backscatter method: ± 10 %
t) Microsection: ± 2 microns
u) Ionic contamination: ± 10 %

4 Catalogue of approved test methods

This standard provides specific test methods in complete detail to permit implementation with
minimal cross-referencing to other specific procedures. The use of generic conditioning
exposures is accomplished in the methods by reference, for example, those described in
IEC 61189-1 and IEC 60068-1, and when applicable, is a mandatory part of the test method
standard.
Each method has its own title, number and revision status to accommodate updating and
improving the methods as industry requirements change or demand new methodology. The
methods are organized in test method groups and individual tests.
5 P: Preparation/conditioning test methods
5.1 Test 5P01: Test-board design guideline
For the details of this test method, see IEC 62137:2004, Clause A.4, the requirements of
which become mandatory when referenced as test 5P01.
5.2 Test 5P02: Standard mounting process for CSP/BGA packages
For the details concerning this test method, see Annex B of IEC 62137:2004, the
requirements of which become mandatory when referenced as test 5P02.
6 V: Visual test methods
(Under consideration)
7 D: Dimensional test methods
(Under consideration)
8 C: Chemical test methods
8.1 Test 5C01: Corrosion, flux
8.1.1 Object
This test method is designed to determine the corrosive properties of flux residues under
extreme environmental conditions. A pellet of solder is melted in contact with the test flux on a
sheet metal test piece. The solder is then exposed to prescribed conditions of humidity and
the resulting corrosion, if any, is assessed visually.

– 12 – 61189-5  IEC:2006(E)
8.1.2 Test specimen
At least 0,035 g of flux solids, 1 g solder paste, 1 g wire, or 1 g preform with an equivalent

amount of solids. Flux solids are defined as the residue from the solid content, flux test

described in IEC 61189-6, test method 6C03. All solvent shall have been evaporated from the

specimen in a chemical fume hood.

8.1.3 Apparatus and reagents
a) Solder pot.
b) Humidity chamber capable of achieving (40 ± 1) °C and (93 ± 2) % relative humidity.

c) Air-circulating drying oven.
d) Microscope having 20× min.
e) Chemicals: All chemicals shall be reagent grade (highly pure, without contamination) and
water shall be distilled or deionized: ammonium persulphate; sulphuric acid, % volume
(v/v); degreasing agent; acetone, or petroleum ether.
f) Analytical balance capable of weighing 0,001 g
g) Copper sheet of a thickness of (0,50 ± 0,05) mm and a purity of 99 %.
8.1.4 Procedures
8.1.4.1 Chemicals
a) Ammonium persulphate (25 % m/v in 0,5 % v/v sulphuric acid). Dissolve 250 g of
ammonium persulphate in water and add cautiously 5 ml of sulphuric acid (density
1,84 g/cm ). Mix, cool, dilute to 1 litre and mix. This solution should be freshly prepared.
b) Sulphuric acid (5 % v/v). To 400 ml of water cautiously add 50 ml of sulphuric acid
(density 1,84 g/cm ). Mix, cool, dilute to 1 litre and mix.
8.1.4.2 Test panel preparation
a) Cut a piece of 50 mm × 50 mm from the copper sheet for each test.
b) Form a circular depression in the centre of each test panel 3 mm deep by forcing a steel
ball of a diameter of 20 mm into a hole of a diameter of 25 mm to form a cup.
c) Bend one corner of each test panel up to facilitate subsequent handling with tongs.
8.1.4.3 Preconditioning test panels
Immediately before performing the test, precondition as follows using clean tongs for

handling.
a) Degrease with a suitable neutral organic solvent such as acetone or petroleum ether.
b) Immerse in 5 % sulphuric acid (by volume) at (65 ± 5) °C for 1 min to remove the tarnish
film.
c) Immerse in a solution of 25 % m/v ammonium persulphate (0,5 % v/v sulphuric acid) at
(23 ± 2) °C for 1 min to etch the surface uniformly.
d) Wash in running tap water for a maximum of 5 s.
e) Immerse in 5 % sulfuric acid (by volume) at (23 ± 2) °C for 1 min.
f) Wash for 5 s in running tap water, then rinse thoroughly in deionized water.
g) Rinse with acetone.
h) Allow to dry in clean air.
i) Use the test piece as soon as possible or store up to 1 h in a closed container.

61189-5  IEC:2006(E) – 13 –
8.1.4.4 Preparation of test solder

a) Weigh (1,00 ± 0,05) g specimen of solder for each test and place in the centre of

depression of each test panel.

b) Degrease solder specimen with a suitable neutral organic solvent such as acetone or

petroleum ether.
c) Solder may be in the form of pellets or by forming tight spirals of solder wire.

8.1.4.5 Test
a) Heat solder pot so that solder bath stabilizes at (235 ± 5) °C in the case of Sn63Pb37 and

Sn60Pb40 alloy. For solder alloys except Sn63Pb37 and Sn60Pb40, the temperature of
the solder pot may be approximately 40 °C higher than the liquid temperature of each
alloy.
b) Liquid flux, place 0,035 g of flux solids into the depression in the test panel. Add solder
sample.
c) Solder paste, cored wire or cored preform, place 1 g of solder paste, flux-cored wire or
cored-preform into the depression in the test panel.
d) Using tongs, lower each test panel onto the surface of the molten solder.
e) Allow the test panel to remain in contact until the solder specimen in the depression of the
test panel melts. Maintain this condition for (5 ± 1) s.
f) Carefully examine the test panel at 20× magnification for subsequent comparison after
humidity exposure. Record observations, especially any discoloration.
g) Preheat test panel to (40 ± 1) °C for (30 ± 2) min.
h) Preset humidity chamber to (40 ± 1) °C and (93 ± 2) % relative humidity.
i) Suspend each test panel vertically (and separately) in the humidity chamber.
j) Expose panels to the above environment for 72 h (3 days). M (moderately active) and H
(highly active) flux may be tested in the cleaned, as well as uncleaned, condition.
8.1.4.6 Evaluation
Carefully examine test panels prior to placing them in the environmental chamber. Note any
discoloration.
After the appropriate exposure period, remove test panels from humidity chamber, examine at
20× magnification and compare with observations noted prior to exposure.
Corrosion is described as follows.

– Excrescences at the interfaces of the flux residue and copper boundary or the residues or
discontinuities in the residues.
– Discrete white or coloured spots in the flux residues.
An initial change of colour which may develop when the test panel is heated during soldering
is disregarded, but subsequent development of green-blue discoloration with observation of
pitting of the copper panel is regarded as corrosion.
8.1.5 Additional information
8.1.5.1 Definition of corrosion
For the purposes of this test method, the following is the definition of corrosion: “chemical
reaction between the copper, the solder, and the constituents of the flux residues, which
occurs after soldering and during exposure to the above environmental conditions."
Colour photos before and after the test are valuable tools in identifying corrosion.

– 14 – 61189-5  IEC:2006(E)
8.1.5.2 Safety
Observe all appropriate precautions on material safety data sheets (MSDS) for chemicals

involved in this test method.
9 M: Mechanical test methods
9.1 Test 5M01: Peel test method for test-board land

For details concerning this test method, see Clause A.3 of IEC 62137, the requirements of

which become mandatory when referenced as test 5M01.

10 E: Electrical test methods
10.1 Test 5E01: Changes of the surface insulation resistance caused by fluxes
10.1.1 Object
This test method is to characterize fluxes by determining the degradation of the electrical
insulation resistance of rigid printed board specimens after exposure to the specified flux.
This test is carried out at high humidity and heat conditions.
10.1.2 Method A
10.1.2.1 Test specimens
a) Comb patterns: The test pattern shown in Figure 1 shall be used for the test specimen.
The individual comb has a line width of 0,4 mm and 0,2 mm spacing. The specimen is
approximately 100 mm × 95 mm in size. Its conductive pattern shall be unpreserved bare
copper.
IEC  1612/06
Figure 1 – Surface insulation resistance pattern
b) Laminate: The laminate material for this test shall be an epoxide woven E-glass laminated
sheet in accordance with IEC 61249-2-7.

61189-5  IEC:2006(E) – 15 –
10.1.2.2 Apparatus
a) A humidity chamber capable of being adjusted to a temperature of (90 ± 2) °C and a

relative humidity of (95 ± 3) %. The chamber should be constructed with stainless steel

inner surfaces and be well insulated. The temperature and humidity measurement should

be taken using sensors such as dry and wet bulb thermometers or solid-state sensors. The

temperature and humidity levels of the test chamber shall be recorded throughout the test,
preferably with independent control sensors.

b) The measurement system shall consist of a measuring device capable of measuring

6 12
surface insulation resistance (SIR) in the range of at least (10 to 10 )Ω. A test and bias

voltage supply capable of providing a variable voltage from (5 to 100)V d.c. (±2 %) with a

1 MΩ load.
Specimen selection system capable of individually selecting each test pattern under
measurement. The system shall incorporate a 1 MΩ current limiting resistor in each
current pathway.
The tolerance of the total measurement system shall be ±5 % up to 10 Ω, ±10 %
10 11 11
between (10 to 10 )Ω, and ±20 % above 10 Ω.
The measurement system shall be verified by substituting a resistor verification coupon in
place of the test specimens while in the chamber at ambient conditions.
c) Three 2 000 ml beakers.
d) Exhaust ventilation hood.
e) Metal tongs.
f) Soft bristle brush.
g) Deionized or distilled water (2 MΩcm, minimum resistivity recommended).
h) Drying oven capable of maintaining at least 50 °C.
10.1.2.3 Test conditions
a) Fluxes that contain more than 1 % by weight organic acid activators, such as adipic acid,
that volatilize significantly at 85 °C, and less than 5 % by weight rosin or modified-rosin
resin should be tested at 40 °C/93 % RH. Fluxes that contain more than 0,1 % by weight
ionic halide should be tested at 85 °C/85 % RH.
b) The test duration shall be not less than 72 h.
c) Test voltages: The testing should be conducted using a voltage gradient of 25 V/mm (=
5 V using the coupon proposed)

10.1.2.4 Specimen preparation
There shall be three test specimens for each liquid flux to be tested in the cleaned state,
having cleaned the boards in accordance with item d) (see Table 2, Sample group A). When
testing liquid fluxes which are intended to remain in the uncleaned state, six test specimens
are required. Three uncleaned test specimens shall be wave-soldered pattern side down
(Table 2, Sample group B) and three shall be wave-soldered pattern side up (Table 2, Sample
group C).
a) Solder paste coupons shall be reflowed pattern side up and either cleaned (Table 2,
Sample group D) or not cleaned (Table 2, Sample group E). In addition, there shall be at
least two unprocessed control coupons for comparison purposes (Table 2, Sample
group F).
b) Positive, permanent and non-contaminating identification of test specimens is of
paramount importance (for example, a vibrating scribe).

– 16 – 61189-5  IEC:2006(E)
c) Visually inspect the test specimens for any obvious defects. If there is any doubt about the

overall quality of any test specimen, the test specimen should be discarded.

Table 2 – Coupons for surface insulation resistance (SIR) testing

Sample group Flux/Solder Clean Number of
coupons
A Yes Yes 3
B Yes No 3
C Yes No 3
D Yes Yes 3
E Yes No 2
F No No 2
d) Clean the test specimen with deionized or distilled water and scrub with a soft bristle
brush for a minimum of 30 s. Spray-rinse thoroughly with deionized or distilled water.
Rinse cleaned area thoroughly with fresh propan-2-ol.
e) An alternative cleaning method is to place the test specimen in an ionic contamination
tester containing 75 % propan-2-ol, 25 % deionized water and process the solution until all
ionics have been removed.
f) During the remainder of the specimen preparation, handle test specimens by the edges
only, or use non-contaminating rubber gloves.
g) If boards are to be stored before treatment, place the boards in contamination-free bags or
containers and close bags (do not heat seal).
10.1.2.5 Solder paste
a) Stencil print the solder paste on to the comb pattern using a 0,150 mm thick stencil. The
stencil shall consist of a series of circular holes of a diameter of 0,4 mm or square
openings that match the conductors of the comb pattern. The registration of the stencil
shall be such that the solder paste is deposited directly on the conductors and does not
cause bridging between conductive patterns. There shall be a minimum of six openings for
each conductor in the comb pattern.
b) The specimens shall be run through a reflow soldering process using the temperature
profile recommended by the supplier.
10.1.2.6 Cleaning of specimens
a) After exposure to flux and solder, specimens to be tested in an uncleaned state shall be
evaluated as described in 10.1.2.8 and 10.1.2.9.
b) After exposure to flux and solder, specimens to be tested in the cleaned state shall be

cleaned using one of the procedures listed below. The cleaning parameters shall be
reported in the qualification test report (Table 3).
c) The specimens to be cleaned shall be cleaned with an appropriate environmentally safe
solvent or aqueous cleaning medium. The use of a commercial in-line or batch cleaner is
preferred. If this is not available, the following laboratory cleaning process shall be
followed.
d) Three specimens shall be cleaned (within 30 min or less) after soldering. For solvent or
aqueous detergent cleaning, three 2 000 ml beakers each containing 1 000 ml of solvent
shall be used so that one beaker serves as the primary cleaning stage and the other two
are used for rinsing purposes. Each test specimen shall be agitated in each beaker for
1 min. In the case of aqueous detergent, one beaker shall contain the cleaning agent and
the remaining beakers shall contain deionized water for rinsing purposes. After the
cleaning procedure is complete, specimens are dried for 2 h at 50 °C. Following cleaning,
the specimens shall be tested as outlined in 10.1.2.8 and 10.1.2.9.

61189-5  IEC:2006(E) – 17 –
10.1.2.7 Preparation of samples for chamber

Visually inspect all combs and discard any combs with bridging of conductors. Use water

white rosin (colour grade of rosin) to solder Teflon-insulated wires to the connection points of

the specimens. Do not attempt to remove the flux residues. Connectors may be used in lieu of

soldering wires but are not recommended. In the event of a dispute, the samples with
soldered wires shall be used as a referee.

10.1.2.8 Connector system – High-resistance measurement verification

a) Prior to connecting test specimens to the measurement system, each cable assembly shall

be connected to the resistor verification coupon inside the humidity chamber at ambient

conditions and a measurement taken. Any cable that does not read within the tolerance
value of the total measurem
...

IEC 61189-5
Edition 1.0 2006-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Test methods for electrical materials, interconnection structures and
assemblies –
Part 5: Test methods for printed board assemblies

Méthodes d'essai pour les matériaux électriques, les structures d'interconnexion
et les ensembles –
Partie 5: Méthodes d'essai des assemblages de cartes à circuit imprimé

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IEC 61189-5
Edition 1.0 2006-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Test methods for electrical materials, interconnection structures and
assemblies –
Part 5: Test methods for printed board assemblies

Méthodes d'essai pour les matériaux électriques, les structures d'interconnexion
et les ensembles –
Partie 5: Méthodes d'essai des assemblages de cartes à circuit imprimé

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
XB
CODE PRIX
ICS 31.180 ISBN 2-8318-9830-7

– 2 – 61189-5 © IEC:2006
CONTENTS
FOREWORD.4
INTRODUCTION.6
1 Scope.7
2 Normative references .7
3 Accuracy, precision and resolution .8
3.1 Accuracy .8
3.2 Precision .8
3.3 Resolution .9
3.4 Report .9
3.5 Student’s t distribution.10
3.6 Suggested uncertainty limits.10
4 Catalogue of approved test methods .11
5 P: Preparation/conditioning test methods.11
5.1 Test 5P01: Test-board design guideline.11
5.2 Test 5P02: Standard mounting process for CSP/BGA packages .11
6 V: Visual test methods.11
7 D: Dimensional test methods .11
8 C: Chemical test methods.11
8.1 Test 5C01: Corrosion, flux.11
9 M: Mechanical test methods .14
9.1 Test 5M01: Peel test method for test-board land .14
10 E: Electrical test methods .14
10.1 Test 5E01: Changes of the surface insulation resistance caused by fluxes .14
10.2 Test 5E02: Surface insulation resistance, assemblies .21
11 N: Environmental test methods.29
11.1 Test 5N01: Reflow solderability test for soldering joint.29
11.2 Test 5N02: Resistance to reflow solderability of test board.30
11.3 Test 5N03: Solderability test for test board land .30
12 X Miscellaneous test methods .30
12.1 Test 5X01: Liquid flux activity, wetting balance method .30
12.2 Test 5X02: Paste flux viscosity – T-Bar spindle method .34
12.3 Test 5X03: Spread test, liquid or extracted solder flux, solder paste and
extracted cored wires or preforms.34
12.4 Test 5X04: Solder paste viscosity – T-Bar spin spindle method (applicable
to 300 Pa·s to 1 600 Pa·s) .37
12.5 Test 5X05: Solder paste viscosity – T-Bar spindle method (applicable to
300 Pa·s).39
12.6 Test 5X06: Solder paste viscosity – Spiral pump method (applicable to
300 Pa·s to 1 600 Pa·s) .41
12.7 Test 5X07: Solder paste viscosity – Spiral pump method (applicable to 300
Pa·s).43
12.8 Test 5X08: Solder paste – Slump test .45
12.9 Test 5X09: Solder paste − Solder ball test .48
12.10 Test 5X10: Solder paste − Tack test .50
12.11 Test 5X11: Solder paste − Wetting test .52
12.12 Test 5X12: Flux residues – Tackiness after drying .54

61189-5 © IEC:2006 – 3 –
12.13 Test 5X13: Spitting of flux-cored wire solder.55
12.14 Test 5X14: Solder pool test.58
Bibliography.60

Figure 1 – Surface insulation resistance pattern .15
Figure 2 – Connector arrangement.17
Figure 3 – Specimen orientation in test chamber.18
Figure 4 – Test method 5E02.23
Figure 5 – Resistor verification coupon .24
Figure 6 – Resistor verification board with protective cover.25
Figure 7 – Test specimen location with respect to chamber air flow .25
Figure 8 – Wetting balance apparatus.32
Figure 9 – Wetting balance curve.33
Figure 10 – Slump test stencil thickness, 0,20 mm.46
Figure 11 – Slump test stencil thickness, 0,10 mm.47
Figure 12 – Solder-ball test evaluation.50
Figure 13 – Solder wetting examples .53
Figure 14 – Test apparatus for spitting test .57

Table 1 – Student’s t distribution.10
Table 2 – Coupons for surface insulation resistance (SIR) testing.16
Table 3 – Qualification test report .21
Table 4 – Suggested test conditions .27
Table 5 – Typical spread areas defined in mm .35
Table 6 – Example of a test report on solder paste .39
Table 7 – Example of a test report on solder paste .41
Table 8 – Example of test report on solder paste .43
Table 9 – Example of test report on solder paste .45
Table 10 – Example of a test report – Stencil thickness, 0,2 mm.48
Table 11 – Example of a test report – Stencil thickness, 0,1 mm.48

– 4 – 61189-5 © IEC:2006
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
TEST METHODS FOR ELECTRICAL MATERIALS,
INTERCONNECTION STRUCTURES AND ASSEMBLIES –

Part 5: Test methods 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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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 has been prepared by IEC technical committee 91:
Electronic assembly technology.
This bilingual version, published in 2008-05, corresponds to the English version.
The text of this standard is based on the following documents:
FDIS Report on voting
91/608/FDIS 91/619/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.
The French version of this standard has not been voted upon.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

61189-5 © IEC:2006 – 5 –
This standard is to be used in conjunction with the following parts of IEC 61189:
Part 1: General test methods and methodology
Part 2: Test methods for materials for interconnection structures
Part 3: Test methods for interconnection structures (printed boards)
Part 4: Test methods for electronic components assembling characteristics (under
consideration)
Part 6: Test methods for materials used in electronic assemblies
and also the following standard:
IEC 60068 series: Environmental testing
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC website 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.
– 6 – 61189-5 © IEC:2006
INTRODUCTION
IEC 61189 relates to test methods for printed boards and printed board assemblies, as well as
related materials or component robustness, 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 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 criterion.
The letter and number combinations are for reference purposes to be used by the relevant
specification. Thus "5C01" represents the first chemical test method described in IEC 61189-5.
In short, in this example, 5 is the number of the part of IEC 61189, C is the group of methods,
and 01 is the test number.
A list of all test methods included in this standard, as well as those under consideration, is
given in Annex B. This annex will be reissued whenever new tests are introduced.

61189-5 © IEC:2006 – 7 –
TEST METHODS FOR ELECTRICAL MATERIALS,
INTERCONNECTION STRUCTURES AND ASSEMBLIES –

Part 5: Test methods 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.
2 Normative references
The following referenced documents are indispensable for the application 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 60068-1:1988, Environmental testing – Part 1: General and guidance
IEC 60068-2-20, Basic environmental testing procedures – Part 2: Tests – Test T: Soldering
IEC 61189-1, Test methods for electrical materials, interconnection structures and assemblies
– Part 1: General test methods and methodology
IEC 61189-3, Test methods for electrical materials, printed boards and other interconnection
structures and assemblies – Part 3: Test methods for interconnection structures (printed
boards)
IEC 61189-6, Test methods for electrical materials, interconnection structures and assemblies
– Part 6: Test methods for materials used in manufacturing electronic assemblies
IEC 61190-1-1, Attachment materials for electronic assembly – Part 1-1: Requirements for
soldering fluxes for high-quality interconnections in electronics assembly
IEC 61190-1-2:2002 , Attachment materials for electronic assembly – Part 1-2:
Requirements for solder 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
IEC 61249-2-7, Materials for printed boards and other interconnecting structures – Part 2-7:
Reinforced base materials clad and unclad – Epoxide woven E-glass laminated sheet of
defined flammability (vertical burning test), copper-clad
IEC 62137:2004, Environmental and endurance testing - Test methods for surface-mount
boards of area array type packages FBGA, BGA, FLGA, LGA, SON and QFN
ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results – Part 2:
Basic method for the determination of repeatability and reproducibility of a standard
measurement method
—————————
This document has been replaced by a new, bilingual edition (2008), but for the purposes of this standard, the 2002 edition
is cited.
– 8 – 61189-5 © IEC:2006
ISO 9001, Quality management systems – Requirements
ISO 9455-1, Soft soldering fluxes – Test methods – Part 1: Determination of non-volatile
matter, gravimetric method
ISO 9455-2, Soft soldering fluxes –Test methods – Part 2: Determination of non-volatile
matter, ebulliometric method
3 Accuracy, precision and resolution
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.
3.1 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 shall
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.
3.2 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 %.
61189-5 © IEC:2006 – 9 –
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
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
3.3 Resolution
It is paramount that the test equipment used is 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).
3.4 Report
In addition to requirements detailed in the test specification, the report shall detail
a) the test method used;
b) the identity of the sample(s);

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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.
3.5 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

3.6 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 %
61189-5 © IEC:2006 – 11 –
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
u) Ionic contamination: ± 10 %
4 Catalogue of approved test methods
This standard provides specific test methods in complete detail to permit implementation with
minimal cross-referencing to other specific procedures. The use of generic conditioning
exposures is accomplished in the methods by reference, for example, those described in
IEC 61189-1 and IEC 60068-1, and when applicable, is a mandatory part of the test method
standard.
Each method has its own title, number and revision status to accommodate updating and
improving the methods as industry requirements change or demand new methodology. The
methods are organized in test method groups and individual tests.
5 P: Preparation/conditioning test methods
5.1 Test 5P01: Test-board design guideline
For the details of this test method, see IEC 62137:2004, Clause A.4, the requirements of
which become mandatory when referenced as test 5P01.
5.2 Test 5P02: Standard mounting process for CSP/BGA packages
For the details concerning this test method, see Annex B of IEC 62137:2004, the
requirements of which become mandatory when referenced as test 5P02.
6 V: Visual test methods
(Under consideration)
7 D: Dimensional test methods
(Under consideration)
8 C: Chemical test methods
8.1 Test 5C01: Corrosion, flux
8.1.1 Object
This test method is designed to determine the corrosive properties of flux residues under
extreme environmental conditions. A pellet of solder is melted in contact with the test flux on a

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sheet metal test piece. The solder is then exposed to prescribed conditions of humidity and
the resulting corrosion, if any, is assessed visually.
8.1.2 Test specimen
At least 0,035 g of flux solids, 1 g solder paste, 1 g wire, or 1 g preform with an equivalent
amount of solids. Flux solids are defined as the residue from the solid content, flux test
described in IEC 61189-6, test method 6C03. All solvent shall have been evaporated from the
specimen in a chemical fume hood.
8.1.3 Apparatus and reagents
a) Solder pot.
b) Humidity chamber capable of achieving (40 ± 1) °C and (93 ± 2) % relative humidity.
c) Air-circulating drying oven.
d) Microscope having 20× min.
e) Chemicals: All chemicals shall be reagent grade (highly pure, without contamination) and
water shall be distilled or deionized: ammonium persulphate; sulphuric acid, % volume
(v/v), degreasing agent; acetone, or petroleum ether.
f) Analytical balance capable of weighing 0,001 g.
g) Copper sheet of a thickness of (0,50 ± 0,05) mm and a purity of 99 %.
8.1.4 Procedures
8.1.4.1 Chemicals
a) Ammonium persulphate (25 % m/v in 0,5 % v/v sulphuric acid). Dissolve 250 g of
ammonium persulphate in water and add cautiously 5 ml of sulphuric acid (density
1,84 g/cm ). Mix, cool, dilute to 1 litre and mix. This solution should be freshly prepared.
b) Sulphuric acid (5 % v/v). To 400 ml of water cautiously add 50 ml of sulphuric acid
(density 1,84 g/cm ). Mix, cool, dilute to 1 litre and mix.
8.1.4.2 Test panel preparation
a) Cut a piece of 50 mm × 50 mm from the copper sheet for each test.
b) Form a circular depression in the centre of each test panel 3 mm deep by forcing a steel
ball of a diameter of 20 mm into a hole of a diameter of 25 mm to form a cup.
c) Bend one corner of each test panel up to facilitate subsequent handling with tongs.
8.1.4.3 Preconditioning test panels
Immediately before performing the test, precondition as follows using clean tongs for
handling.
a) Degrease with a suitable neutral organic solvent such as acetone or petroleum ether.
b) Immerse in 5 % sulphuric acid (by volume) at (65 ± 5) °C for 1 min to remove the tarnish
film.
c) Immerse in a solution of 25 % m/v ammonium persulphate (0,5 % v/v sulphuric acid) at
(23 ± 2) °C for 1 min to etch the surface uniformly.
d) Wash in running tap water for a maximum of 5 s.
e) Immerse in 5 % sulfuric acid (by volume) at (23 ± 2) °C for 1 min.
f) Wash for 5 s in running tap water, then rinse thoroughly in deionized water.
g) Rinse with acetone.
61189-5 © IEC:2006 – 13 –
h) Allow to dry in clean air.
i) Use the test piece as soon as possible or store up to 1 h in a closed container.
8.1.4.4 Preparation of test solder
a) Weigh (1,00 ± 0,05) g specimen of solder for each test and place in the centre of
depression of each test panel.
b) Degrease solder specimen with a suitable neutral organic solvent such as acetone or
petroleum ether.
c) Solder may be in the form of pellets or by forming tight spirals of solder wire.
8.1.4.5 Test
a) Heat solder pot so that solder bath stabilizes at (235 ± 5) °C in the case of Sn63Pb37 and
Sn60Pb40 alloy. For solder alloys except Sn63Pb37 and Sn60Pb40, the temperature of
the solder pot may be approximately 40 °C higher than the liquid temperature of each
alloy.
b) Liquid flux, place 0,035 g of flux solids into the depression in the test panel. Add solder
sample.
c) Solder paste, cored wire or cored preform, place 1 g of solder paste, flux-cored wire or
cored-preform into the depression in the test panel.
d) Using tongs, lower each test panel onto the surface of the molten solder.
e) Allow the test panel to remain in contact until the solder specimen in the depression of the
test panel melts. Maintain this condition for (5 ± 1) s.
f) Carefully examine the test panel at 20× magnification for subsequent comparison after
humidity exposure. Record observations, especially any discoloration.
g) Preheat test panel to (40 ± 1) °C for (30 ± 2) min.
h) Preset humidity chamber to (40 ± 1) °C and (93 ± 2) % relative humidity.
i) Suspend each test panel vertically (and separately) in the humidity chamber.
j) Expose panels to the above environment for 72 h (3 days). M (moderately active) and H
(highly active) flux may be tested in the cleaned, as well as uncleaned, condition.
8.1.4.6 Evaluation
Carefully examine test panels prior to placing them in the environmental chamber. Note any
discoloration.
After the appropriate exposure period, remove test panels from humidity chamber, examine at
20× magnification and compare with observations noted prior to exposure.
Corrosion is described as follows.
– Excrescences at the interfaces of the flux residue and copper boundary or the residues or
discontinuities in the residues.
– Discrete white or coloured spots in the flux residues.
An initial change of colour which may develop when the test panel is heated during soldering
is disregarded, but subsequent development of green-blue discoloration with observation of
pitting of the copper panel is regarded as corrosion.

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8.1.5 Additional information
8.1.5.1 Definition of corrosion
For the purposes of this test method, the following is the definition of corrosion: “chemical
reaction between the copper, the solder, and the constituents of the flux residues, which
occurs after soldering and during exposure to the above environmental conditions."
Colour photos before and after the test are valuable tools in identifying corrosion.
8.1.5.2 Safety
Observe all appropriate precautions on material safety data sheets (MSDS) for chemicals
involved in this test method.
9 M: Mechanical test methods
9.1 Test 5M01: Peel test method for test-board land
For details concerning this test method, see Clause A.3 of IEC 62137, the requirements of
which become mandatory when referenced as test 5M01.
10 E: Electrical test methods
10.1 Test 5E01: Changes of the surface insulation resistance caused by fluxes
10.1.1 Object
This test method is to characterize fluxes by determining the degradation of the electrical
insulation resistance of rigid printed board specimens after exposure to the specified flux.
This test is carried out at high humidity and heat conditions.
10.1.2 Method A
10.1.2.1 Test specimens
a) Comb patterns: The test pattern shown in Figure 1 shall be used for the test specimen.
The individual comb has a line width of 0,4 mm and 0,2 mm spacing. The specimen is
approximately 100 mm × 95 mm in size. Its conductive pattern shall be unpreserved bare
copper.
61189-5 © IEC:2006 – 15 –
IEC  1612/06
Figure 1 – Surface insulation resistance pattern
b) Laminate: The laminate material for this test shall be an epoxide woven E-glass laminated
sheet in accordance with IEC 61249-2-7.
10.1.2.2 Apparatus
a) A humidity chamber capable of being adjusted to a temperature of (90 ± 2) °C and a
relative humidity of (95 ± 3) %. The chamber should be constructed with stainless steel
inner surfaces and be well insulated. The temperature and humidity measurement should
be taken using sensors such as dry and wet bulb thermometers or solid-state sensors. The
temperature and humidity levels of the test chamber shall be recorded throughout the test,
preferably with independent control sensors.
b) The measurement system shall consist of a measuring device capable of measuring
6 12
surface insulation resistance (SIR) in the range of at least (10 to 10 )Ω. A test and bias
voltage supply capable of providing a variable voltage from (5 to 100)V d.c. (±2 %) with a
1 MΩ load.
Specimen selection system capable of individually selecting each test pattern under
measurement. The system shall incorporate a 1 MΩ current limiting resistor in each
current pathway.
The tolerance of the total measurement system shall be ±5 % up to 10 Ω, ±10 %
10 11 11
between (10 to 10 )Ω, and ±20 % above 10 Ω.
The measurement system shall be verified by substituting a resistor verification coupon in
place of the test specimens while in the chamber at ambient conditions.
c) Three 2 000 ml beakers.
d) Exhaust ventilation hood.
e) Metal tongs.
f) Soft bristle brush.
g) Deionized or distilled water (2 MΩcm, minimum resistivity recommended).
h) Drying oven capable of maintaining at least 50 °C.

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10.1.2.3 Test conditions
a) Fluxes that contain more than 1 % by weight organic acid activators, such as adipic acid,
that volatilize significantly at 85 °C, and less than 5 % by weight rosin or modified-rosin
resin should be tested at 40 °C/93 % RH. Fluxes that contain more than 0,1 % by weight
ionic halide should be tested at 85 °C/85 % RH.
b) The test duration shall be not less than 72 h.
c) Test voltages: The testing should be conducted using a voltage gradient of 25 V/mm (=
5 V using the coupon proposed).
10.1.2.4 Specimen preparation
There shall be three test specimens for each liquid flux to be tested in the cleaned state,
having cleaned the boards in accordance with item d) (see Table 2, Sample group A). When
testing liquid fluxes which are intended to remain in the uncleaned state, six test specimens
are required. Three uncleaned test specimens shall be wave-soldered pattern side down
(Table 2, Sample group B) and three shall be wave-soldered pattern side up (Table 2, Sample
group C).
a) Solder paste coupons shall be reflowed pattern side up and either cleaned (Table 2,
Sample group D) or not cleaned (Table 2, Sample group E). In addition, there shall be at
least two unprocessed control coupons for comparison purposes (Table 2, Sample
group F).
b) Positive, permanent and non-contaminating identification of test specimens is of
paramount importance (for example, a vibrating scribe).
c) Visually inspect the test specimens for any obvious defects. If there is any doubt about the
overall quality of any test specimen, the test specimen should be discarded.
Table 2 – Coupons for surface insulation resistance (SIR) testing
Sample group Flux/Solder Clean Number of
coupons
A Yes Yes 3
B Yes No 3
C Yes No 3
D Yes Yes 3
E Yes No 2
F No No 2
d) Clean the test specimen with deionized or distilled water and scrub with a soft bristle
brush for a minimum of 30 s. Spray-rinse thoroughly with deionized or distilled water.
Rinse cleaned area thoroughly with fresh propan-2-ol.
e) An alternative cleaning method is to place the test specimen in an ionic contamination
tester containing 75 % propan-2-ol, 25 % deionized water and process the solution until all
ionics have been removed.
f) During the remainder of the specimen preparation, handle test specimens by the edges
only, or use non-contaminating rubber gloves.
g) If boards are to be stored before treatment, place the boards in contamination-free bags or
containers and close bags (do not heat seal).
10.1.2.5 Solder paste
a) Stencil print the solder paste on to the comb pattern using a 0,150 mm thick stencil. The
stencil shall consist of a series of circular holes of a diameter of 0,4 mm or square
openings that match the conductors of the comb pattern. The registration of the stencil
shall be such that the solder paste is deposited directly on the conductors and does not

61189-5 © IEC:2006 – 17 –
cause bridging between conductive patterns. There shall be a minimum of six openings for
each conductor in the comb pattern.
b) The specimens shall be run through a reflow soldering process using the temperature
profile recommended by the supplier.
10.1.2.6 Cleaning of specimens
a) After exposure to flux and solder, specimens to be tested in an uncleaned state shall be
evaluated as described in 10.1.2.8 and 10.1.2.9.
b) After exposure to flux and solder, specimens to be tested in the cleaned state shall be
cleaned using one of the procedures listed below. The cleaning parameters shall be
reported in the
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