IEC 62137-1-1:2007

IEC 62137-1-1
Edition 1.0 2007-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Surface mounting technology – Environmental and endurance test methods for
surface mount solder joint –
Part 1-1: Pull strength test
Technologie de montage en surface – Méthodes d’essais d’environnement et
d’endurance des joints brasés montés en surface –
Partie 1-1: Essai de résistance à la traction

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IEC 62137-1-1
Edition 1.0 2007-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Surface mounting technology – Environmental and endurance test methods for
surface mount solder joint –
Part 1-1: Pull strength test
Technologie de montage en surface – Méthodes d’essais d’environnement et
d’endurance des joints brasés montés en surface –
Partie 1-1: Essai de résistance à la traction

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
P
CODE PRIX
ICS 31.190 ISBN 2-8318-9782-3
– 2 – 62137-1-1 © IEC:2007
CONTENTS
FOREWORD.3
1 Scope.5
2 Normative references .5
3 Terms and definitions .5
4 General remarks.6
5 Test equipment and materials.7
5.1 Flow soldering equipment.7
5.2 Reflow soldering equipment .7
5.3 Pull strength test equipment .7
5.4 Optical microscope.7
5.5 Test substrate .7
5.6 Solder alloy .8
5.7 Flux for flow soldering .8
5.8 Solder paste.8
6 Mounting method.8
6.1 Flow soldering.8
6.2 Reflow soldering.9
7 Test conditions .10
7.1 Test: Rapid change of temperature.10
7.2 Pull strength test .10
8 Test procedure .10
8.1 Test sequence.10
8.2 Pre-conditioning .11
8.3 Initial pull strength measurement.11
8.4 Rapid change of temperature .11
8.5 Recovery.11
8.6 Intermediate/final pull strength measurement .11
9 Items to be included in the test report.11
10 Items to be given in the product specification .12
Annex A (normative) Pull strength test – Details .13
Bibliography.15

Figure 1 – Gull-wing leaded component .6
Figure 2 – Area under evaluation in the pull strength test.7
Figure 3 – Example of a flow soldering profile (actual measurement for double-wave
soldering) .9
Figure 4 – Typical reflow profile .10
Figure 5 – Test procedure.11
Figure A.1 – Pull strength test.14
Figure A.2 – An example of the shape of the tip of the pulling jig .14
Figure A.3 – Failure modes in pull strength test .14

62137-1-1 © IEC:2007 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SURFACE MOUNTING TECHNOLOGY –
ENVIRONMENTAL AND ENDURANCE TEST METHODS
FOR SURFACE MOUNT SOLDER JOINT –

Part 1-1: Pull strength test
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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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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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 62137-1-1 has been prepared by IEC technical committee 91:
Electronics 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
91/681/FDIS 91/697/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.

– 4 – 62137-1-1 © IEC:2007
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all the parts in the IEC 62137 series, under the general title Surface mounting
technology – Environmental and endurance test methods for surface mount solder joint, 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 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.
62137-1-1 © IEC:2007 – 5 –
SURFACE MOUNTING TECHNOLOGY –
ENVIRONMENTAL AND ENDURANCE TEST METHODS
FOR SURFACE MOUNT SOLDER JOINT –

Part 1-1: Pull strength test
1 Scope
The test method described in this part of IEC 62137 is applicable to gull-wing lead surface
mounting components.
The method is designed to test and evaluate the endurance of the solder joint between
component leads and lands on a substrate, by means of a pull type mechanical stress. This
test is suitable for evaluating the effects of repeated temperature change on the strength of
the solder joint between component terminals and lands on a substrate.
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, Environmental testing – Part 1: General and guidance
IEC 60068-2-14, Environmental testing – Part 2-14: Tests – Test N: Change of temperature
IEC 60194, Printed board design, manufacture and assembly – Terms and definitions (only
available in English)
IEC 61188-5-5, Printed boards and printed board assemblies – Design and use – Part 5-5:
Attachment (land/joint) considerations – Components with gull-wing leads on four sides (only
available in English)
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, Attachment materials for electronic assembly – Part 1-2: Requirements for
soldering pastes for high-quality interconnects in electronics assembly (only available in
English)
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 (only available in English)
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
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

– 6 – 62137-1-1 © IEC:2007
NOTE Key terms used in this standard are taken mostly from IEC 60194 and IEC 60068-1.
3.1
gull-wing lead
lead stretching out from a surface mount component as illustrated in Figure 1

Gull-wing lead
IEC  1173/07
Figure 1 – Gull-wing leaded component
3.2
pull strength
maximum force to break the joint of a lead to board when a gull-wing lead of a surface mount
component is pulled using a pulling tool at an angle of 45 ° to the board surface
3.3
pull speed
moving speed of the pulling tool holding a gull-wing lead of a component mounted on board in
pull strength test
4 General remarks
The mechanical properties of the joint between leads to lands on a printed wiring board using
lead-free solder are not the same for the joint using tin-lead solder due to the difference in
composing elements of the solders. Thus it becomes important to test the mechanical
properties of solder joints, using different solder alloys, and after temperature cycling stress
have been applied.
In this test method, the test specimens are mounted on a substrate either by flow soldering or
by reflow soldering. The durability of the solder joints is evaluated first by exposing the
electronic components to rapid changes of temperature and after that applying pull strength to
the soldered joint.
Users of gull-wing components subjected to these tests should check that the results ensure
an adequate margin of attachment strength bearing in mind the mass of the component, the
number of leads and the specified mechanical environment of the electronic assembly for
which the component is intended.
NOTE 1 The exposure temperatures in this test may exceed the rated temperature range of the specific electronic
component.
NOTE 2 This test is not a test to measure the strength of the electronic components. The test method to evaluate
the robustness of the joint to a board is described in IEC 60068-2-21.
NOTE 3 Where the tests on a single component have been performed on more than one lead, the lowest strength
figure should be assumed for all leads when calculating the overall attachment strength．
The area of a joint to be evaluated is illustrated in Figure 2.

62137-1-1 © IEC:2007 – 7 –
Component
lead
Component lead
Enlarge
Plated layers
Solder
Evaluation area
Intermetallic compound
layers
Substrate
Substrate land
Substrate
IEC  1174/07
Figure 2 – Area under evaluation in the pull strength test
5 Test equipment and materials
5.1 Flow soldering equipment
The equipment used for the flow soldering is a solder bath that can realize the temperature
profile as specified in 6.1. An example of the temperature profile is given in Figure 3.
5.2 Reflow soldering equipment
The reflow soldering oven shall be able to realize the temperature profile as specified in 6.2.
An example of the temperature profile is given in Figure 4.
5.3 Pull strength test equipment
Unless otherwise specified, equipment with the following features shall be used for the pull
test.
The pull strength test equipment is composed of tension testing machine, a pulling tool, a jig
to fasten a substrate, and an electronic recorder. The tension testing machine shall realize
the pull speed specified in Annex A. The jig to fasten a substrate shall be designed so that a
pull force can be applied to a specimen lead at an angle of 45° to the substrate. The recorder
shall be able to record the maximum force applied to a lead to break the soldered joint. The
accuracy of the recorded data shall be better than ±1 % of measured values.
5.4 Optical microscope
The microscope shall be able to observe an object with a magnification approximately of 50 X
to 250 X. It shall also be equipped with a lamp that can give an illumination level of
approximately 2 000 lx to the object.
5.5 Test substrate
Unless otherwise prescribed by the relevant specification, the test shall be conducted on a
specimen (device) mounted by its normal means on the following substrate.
a) Material: Epoxide woven glass fabric copper-clad laminated sheet, general purpose grade
(IEC 61249-2-7), with foil bonded to one side and a nominal thickness of the sheet,
including the metal foil, of 1,6 mm with a tolerance of ±0,20 mm. The copper foil shall have
a thickness of 0,035 mm ± 0,010 mm.

– 8 – 62137-1-1 © IEC:2007
b) Size: The size of the substrate depends on the size and shape of a surface mount device
soldered on the substrate. The substrate shall be able to be fastened to the pull test
equipment.
c) Land geometry: The shape and size of a land shall comply with IEC 61188-5-5 or the
land geometry recommended by the respective component supplier. Since IEC 61188-5-5
provides for three different land pattern geometries, and different suppliers provide
different recommendations, the relationship between the component gull-wing foot print
and the land pattern used in the testing shall be recorded in accordance with the following:
– land protrusion at the lead toe: minimum;
– land protrusion at the lead heel: minimum;
– land protrusion at the lead side: minimum.
d) Surface protection: The solderable areas of the substrate (lands) shall be protected
against oxidization by suitable means, e.g. by an organic surface protection layer (OSP).
This protective layer shall not adversely have an effect on the solderability of the lands
under the soldering conditions of the reflow soldering equipment described in 6.2.
5.6 Solder alloy
Unless otherwise specified, the solder alloy shall consist of a ternary composition of Sn, Ag
and Cu with the Ag content ranking from 3,0 % to 4,0 % by weight and the Cu content ranking
from 0,5 % to 1,0 % by weight with Sn for balance, e.g. SnAg3,0Cu0,5. The solder alloy shall
be in accordance with IEC 61190-1-3.
5.7 Flux for flow soldering
Unless otherwise specified, the flux used in this test shall comply with IEC 61190-1-1.
5.8 Solder paste
Unless otherwise specified, the solder paste used in this test shall comply with IEC 61190-1-2.
The solder specified in 5.6 shall be used for the solder paste.
6 Mounting method
The test specimen shall be mounted to the substrate by one of the methods given in 6.1 and
6.2.
6.1 Flow soldering
The following steps shall be taken.
a) The test specimen shall be fixed to the substrate specified in 5.5 by an adhesive.
b) A flux as specified in 5.7 shall be supplied by means of foam or by spraying.
c) Unless otherwise specified, a flow-soldering equipment specified in 5.1 shall be used to
solder the leads under the conditions given below. The temperature is measured at the
land immersed to molten solder.
d) Preheating temperature is 100 °C to 120 °C. The soldering temperature (temperature of
the solder bath) is (250 ± 5) °C for 3 s to 5 s. A typical soldering profile is given in
Figure 3.
62137-1-1 © IEC:2007 – 9 –
Solder contact time A + B =3 s to 5 s
Preheating temperature: 100 °C to 120 °C
Preheating time
30 s to 90 s
Solder bath temperature: 250 °C ± 5 °C
Temperature measured at a land
50 immersed into solder
0 20 40 60 80 100 120 140 160
Time  s
IEC  1175/07
Figure 3 – Example of a flow soldering profile
(actual measurement for double-wave soldering)
6.2 Reflow soldering
The following steps shall be taken.
a) Apply the solder paste specified in 5.8 to the lands of a test substrate as specified in 5.5,
using a metal mask with openings of the same size, shape and configuration as the lands
on the substrate, made of stainless steel with a thickness of 100 μm to 150 μm.
b) Mount the test specimen on the test substrate with solder paste applied.
c) Use the reflow-soldering equipment specified in 5.2 to solder the terminals under the
conditions given below. Typical temperature profile of reflow soldering is given in Figure 4
as proposed in IEC 61760-1. The temperature is measured at the land.
Temperature  °C
– 10 – 62137-1-1 © IEC:2007
SnAgCu Reflow
250 °C
245 °C
235 °C
220 °C
180 °C
Preheating
ca 45 s … 90 s > 220 °C
150 °C
Typical
Ramp down rate < 6 k/s
Ramp up rate < 3 k/s
0 30 60 90 120 150 180 210 240 270 300 330 360
Time  s
Continous line: typical process (terminal temperaure)
Dotted line: process limits. Bottom process limit (terminal temperature). Upper process limit (top surface temperature)
IEC  1176/07
Figure 4 – Typical reflow profile
7 Test conditions
7.1 Test: Rapid change of temperature
Unless otherwise specified, the following test conditions shall be applied:
a) rapid change of temperature; test Na, specified in IEC 60068-2-14;
b) the lower temperature (T ) is -40 °C and the higher temperature (T ) is +125 °C;
A B
c) the exposure time to both higher and lower temperatures is 30 min;
d) the number of temperature cycles is 500 (intermediate) and 1 000 (final).
7.2 Pull strength test
Unless otherwise specified, the pull strength test shall be performed according to the test
procedure described in Annex A.
8 Test procedure
8.1 Test sequence
Unless otherwise specified, the sequence of tests shall comply with Figure 5.
NOTE This test is a destructive test. The tested specimen is not to be used for further tests in the test sequence.
Temperature  °C
62137-1-1 © IEC:2007 – 11 –
Mounting (6)
Pull strength
Initial (8.3)
Pre-conditioning (8.2)
Recovery Pull strength
Thermal cycle
Intermediate (8.6)
(8.5)
500 cycles (7.1)
Thermal cycle
Recovery Pull strength
1 000 cycles (7.1) (8.5) Final (8.6)
IEC  1177/07
Figure 5 – Test procedure
8.2 Pre-conditioning
Flux elimination should be specified in the product specification. Unless otherwise specified,
leave the specimen for more than 4 h at the standard atmospheric conditions for
measurements and tests (specified in IEC 60068-1).
8.3 Initial pull strength measurement
Unless otherwise specified, after pre-conditioning as specified in 8.2, the pull strength test as
specified in 7.2 shall be performed. The value of the force needed to break the joint and the
failure mode (see Figure A.3) shall be recorded.
8.4 Rapid change of temperature
Perform the test as specified in 7.1.
8.5 Recovery
After finishing the specified temperature cycles, leave the specimen for more than 4 h at the
standard atmospheric conditions for measurements and tests (specified in IEC 60068-1).
8.6 Intermediate/final pull strength measurement
Unless otherwise specified, the shear strength test as specified in 7.2 shall be performed. The
value of the force needed to break the joint and the failure mode (see Figure A.3) shall be
recorded.
9 Items to be included in the test report
The following items shall be included.
a) Date
b) Name of the test organization
c) Name of the electronic component, type, size, body dimensions, lead pitch
d) Material of the component terminals, and layer structure, if applicable
e) Surface finish of the component terminals
f) Material of the test substrate, size, structure of layers
g) Geometry of substrate lands and layer structure, if applicable
1) Land protrusion at the terminal toe
2) Land protrusion at the terminal heel

– 12 – 62137-1-1 © IEC:2007
3) Land protrusion at the terminal side
h) Type of solder alloy and flux used for flow soldering
i) Type of solder alloy and solder paste for reflow soldering
j) Preheat temperature, solder temperature, contact time to solder, and the atmosphere
(oxygen content if soldered in nitrogen atmosphere) for flow soldering
k) Temperature profile of reflow soldering and the atmosphere (oxygen content, if soldered in
nitrogen atmosphere)
l) Test condition of rapid temperature change test and number of cycles
m) Type of tension test equipment
n) Details of the pulling tool
o) Details of the jig to fasten the substrate (illustration(s) recommended)
p) Pulling angle to the substrate
q) Pulling speed
r) The pull strength value to break the solder joint
s) The failure mode in pull strength test
10 Items to be given in the product specification
The following items shall be included.
a) Test substrate (5.5)
b) Solder (5.8)
c) Flux for flow soldering (5.7)
d) Solder paste (5.8)
e) Temperature profile in flow soldering (6.1c)
f) Application method of solder paste (6.2a)
g) Temperature profile for reflow soldering (6.2c)
h) Test condition of rapid temperature change test (severity, higher temperature, lower
temperature, exposure time, number of cycles) (7.1)
i) Test condition of pull strength test (7.2)
j) Test procedure (8.1)
k) Pre-conditioning (8.2)
l) Initial pull strength measurement (8.3)
m) Intermediate/final pull strength measurement (8.6)

62137-1-1 © IEC:2007 – 13 –
Annex A
(normative)
Pull strength test – Details
A.1 Object
Annex A specifies details of the shear strength test given in 7.2.
A.2 Test method
A.2.1 Preconditioning
After soldering leave the specimen for more than 4 h at the standard atmospheric conditions
for measurements and tests (specified in IEC 60068-1). An appearance inspection can be
performed during that time.
A.2.2 Fastening of the test board
The test board shall be fastened to a jig by bolt and nut as illustrated in Figure A.1 so that the
pulling direction of a lead is 45° relative to the substrate.
A.2.3 Applying of pull force
Set the pulling tool to the inside of a component lead．An example of a pulling tool is shown
in Figure A.2.
Choose the pulling speed. When not given by the relevant specification, a suitable pulling
speed shall be determined by pre-tests using additional specimens. The time required to
break a joint should be in the range between several tens of seconds to several minutes.
NOTE 1 A recommended pulling speed for gull-wing lead of SOIC, TSOP, QFP with lead pitch of 0,5 mm is
0,008 3 mm/s (0,5 mm/min).
NOTE 2 It is recommended that the failure modes “failure of component” and “pulling off the land” do not occur at
the chosen test speed.
A.2.4 Pull strength
The pulling tool shall be moved gradually at a speed described in A.2.3, until the joint breaks.
The force shall be monitored throughout the period during which the force is applied. The
maximum value measured is the pull strength of the joint.
Record the destruction mode according to Figure A.3.
A.2.5 Repeat procedure
The pull strength procedure shall be repeated a number of times in each of the directions that
the gull-wing lead terminations emanate from the body of the component. The number of pull
strength procedures shall be of sufficient quantity in order to establish statistically significant
data for the entire component periphery.
NOTE For example, 20 pins (5 pins for each side of QFP) except for the corner pins were tested and the average
value of 20 tests was adopted as the pull strength in the case with 208-pin QFP with pitch size of 0,5 mm. The
measurement value of the corner pin does not represent typical pull strength of the QFP, because the land at the
corner has unique shape and the corner pin easily bends.

– 14 – 62137-1-1 © IEC:2007
45°
Substrate
Fastening jig
IEC  1178/07
Figure A.1 – Pull strength test

84°
R0,1
C0,2 C0,2
0,4 0,4
IEC  1179/07
Figure A.2 – An example of the shape of the tip of the pulling jig
...