IEC 60749-40:2011

IEC 60749-40 ®
Edition 1.0 2011-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Semiconductor devices – Mechanical and climatic test methods –
Part 40: Board level drop test method using a strain gauge

Dispositifs à semiconducteurs – Méthodes d'essais climatiques et mécaniques –
Partie 40: Méthode d’essai de chute au niveau de la carte avec utilisation d’une
jauge de contrainte
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IEC 60749-40 ®
Edition 1.0 2011-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Semiconductor devices – Mechanical and climatic test methods –
Part 40: Board level drop test method using a strain gauge

Dispositifs à semiconducteurs – Méthodes d'essais climatiques et mécaniques –
Partie 40: Méthode d’essai de chute au niveau de la carte avec utilisation d’une
jauge de contrainte
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX S
ICS 31.080.01 ISBN 978-2-88912-583-8

– 2– 60749-40  IEC:2011
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Test equipment . 6
5 Test procedure . 6
5.1 Test specimen . 6
5.2 Test substrate . 6
5.3 Solder paste . 6
5.4 Mounting method . 7
5.5 Pre-conditionings . 7
5.6 Initial measurements . 7
5.7 Intermediate measurement . 7
5.8 Final measurement . 7
6 Test method . 7
6.1 Purpose of test method . 7
6.2 Example of drop test equipment . 7
6.3 Example of substrate-securing jig . 8
6.4 Example of distance between supporting points . 8
6.5 Example of impacting surface . 8
6.6 Strain gauge . 8
6.7 Strain gauge attachment . 8
6.8 Strain measurement instrument . 9
6.9 Test condition . 10
6.9.1 Drop test conditions . 10
6.9.2 Test procedure . 10
6.9.3 Drop height. 11
6.9.4 Pre-test characterization . 11
6.9.5 Direction . 13
6.9.6 Number of drops . 13
7 Summary . 13
Annex A (normative) Drop impact test method using test rod . 15
Annex B (informative) An example of strain gauge attachment procedure . 18

Figure 1 – Example of drop test equipment and substrate securing jig . 9
Figure 2 – Position of strain gauge attachment . 10
Figure 3 – Strain measurement instrument . 11
Figure 4 – Waveform of strain and electrical conductivity of daisy chain . 11
Figure 5a – Number of times of drop to failure . 13
Figure 5b – Pulse duration . 13
Figure 5 – Correlation strain and number of failures and strain and pulse duration . 13
Figure 6 – Correlation between pulse duration and distance between supporting points . 13
Figure 7 – Correlation between the number of times of failure and the maximum strain. 14
Figure 8 – Direction of dropping . 14

60749-40  IEC:2011 – 3 –
Figure A.1 – Outline of test apparatus . 16
Figure A.2 – Waveform of strain and electrical conductivity of a daisy chain . 18
Figure B.1 – Equipment and materials . 19
Figure B.2 – Example of Attaching Strain Gauge and Guide Mark Dimensions . 20
Figure B.3 – Strain gauge attachment procedure, part 1 . 21
Figure B.4 – Strain gauge attachment procedure, part 2 . 22

– 4– 60749-40  IEC:2011
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SEMICONDUCTOR DEVICES –
MECHANICAL AND CLIMATIC TEST METHODS –

Part 40: Board level drop test method using a strain gauge

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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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 60749-40 has been prepared by IEC technical committee 47:
Semiconductor devices.
The text of this standard is based on the following documents:
FDIS Report on voting
47/2094/FDIS 47/2100/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.

60749-40  IEC:2011 – 5 –
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 60749 series, under the general title Semiconductor devices –
Mechanical and climatic test methods, can be found in the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this publication using a
colour printer.
– 6– 60749-40  IEC:2011
SEMICONDUCTOR DEVICES –
MECHANICAL AND CLIMATIC TEST METHODS –

Part 40: Board level drop test method using a strain gauge

1 Scope
This part of IEC 60749 is intended to evaluate and compare drop performance of a surface
mount semiconductor device for handheld electronic product applications in an accelerated
test environment, where excessive flexure of a circuit board causes product failure. The
purpose is to standardize test methodology to provide a reproducible assessment of the drop
test performance of a surface mounted semiconductor devices while duplicating the failure
modes normally observed during product level test.
This international standard uses a strain gauge to measure the strain and strain rate of a
board in the vicinity of a component. Test method IEC 60749-37 uses an accelerometer to
measure the mechanical shock duration and magnitude applied which is proportional to the
stress on a given component mounted on a standard board. The detailed specification shall
state which test method is to be used.
NOTE 1 Although this test can evaluate a structure where the mounting method and its conditions, the design of a
printed wired board, solder material, the mounting capability of a semiconductor device, etc. are combined, it does
not solely evaluate the mounting capability of a semiconductor device.
NOTE 2 The result of this test is strongly influenced by the differences between soldering conditions, the design
of the land pattern of a printed wired board, solder material, etc. Therefore, in carrying out this test, it is necessary
to recognize that this test cannot intrinsically guarantee the reliability of the solder joint of the semiconductor
devices.
NOTE 3 When the mechanical stress which is generated by this test does not occur in the actual application of
the device, implementation of this test is unnecessary.
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 60749-37, Semiconductor devices – Mechanical and climatic test methods – Part 37:
Board level drop test method using an accelerometer
3 Terms and definitions
For purposes of this document, the following terms and definitions apply.
3.1
device
single electronic component to be surface mounted
3.2
drop impact strength
strength of the test substrate held by a jig that is dropped from a defined height, as
represented by the number of cyclic drops that finally cause fracture on the joint between a
device and a PWB copper land
60749-40  IEC:2011 – 7 –
3.3
strain
strain of surface of substrate
degree of stretching observed when the test substrate is distorted
NOTE The strain is a numeric dimensionless quantity.
3.4
maximum strain
tensile side (+) of the strain waveform
3.5
pulse duration
duration between the instant when the acceleration first reaches 10 % of its specified peak
level and the instant when the acceleration first returns to 10 % of the specified peak level
after having reached that peak level
3.6
momentary interruption detector
equipment which detects extremely short electrical discontinuity (momentary interruptions) in
a daisy-chain circuit
4 Test equipment
The equipment shall be selected to satisfy the test conditions specified in Clause 6.
Alternatively, the test method described in Annex A can be used.
5 Test procedure
5.1 Test specimen
Unless otherwise specified, specimen devices shall be of a structure that allows continuity to
be checked (e.g., daisy chain). They shall be of a design based on the same specifications as
devices in actual use.
The test specimens shall be on a daisy-chained substrate on the lead frame of a surface
mounted device or on a substrate that is a carrier of a BGA, LGA, or SON, or the actual
device shall be used.
NOTE When using daisy-chain connections, care should be taken not to cause any failure in wiring patterns on
the test substrate. For example, the wiring patterns should be drawn in a crosswise direction on the test substrate,
not in a longitudinal direction.
5.2 Test substrate
The test substrate shall be prepared in accordance with the relevant specification, preferably
using a substrate of the same structures an actual electrical device.
Unless otherwise specified, a solder mask defined (SMD) land is desirable for a BGA and a
non solder mask defined (NSMD) land for a QFP. For a BGA, it is desirable to match the land
size of the test substrate with the land size of the package.
5.3 Solder paste
The solder paste shall be prepared in accordance with the relevant specification.

– 8– 60749-40  IEC:2011
5.4 Mounting method
The mounting method shall prepared in accordance with the relevant specification. However,
one test specimen shall be mounted in the centre of the test substrate.
5.5 Pre-conditionings
When specified in the relevant specification, carry out moisture soaking and soldering heat
stress testing before the board level drop test.
5.6 Initial measurements
The initial measurement shall be carried out in accordance with the relevant specification.
5.7 Intermediate measurement
Intermediate measurement shall be carried out in accordance with the relevant specification.
NOTE When determining failure after a drop test, a failure can wrongly be considered as acceptable because of
electrical contact of a disconnect. Therefore, when determining failure, checking the daisy-chain signal lines with a
momentary interruption detector or other similar equipment is advised. When using this technique, the resolution of
the momentary interruption detector shall be capable of detecting 100μs of momentary discontinuity.
5.8 Final measurement
The final measurement shall be carried in accordance with the relevant specification.
A sufficient number of failures from the test lot shall be subjected to failure analysis to
determine the root cause and to identify the failure mechanism. Each failure site shall be
clearly identified as “device failure”, “interconnect failure”, or “board failure”.
6 Test method
6.1 Purpose of test method
This test method specifies the drop test conducted with the fall height based on measured
strain using a strain gauge set on the test substrate.
NOTE This test method uses drop test equipment, a substrate-securing jig and a strain measurement instrument.
Because the test equipment is verified using the value of strain measured by a strain gauge attached to the surface
of the test substrate, the test result does not depend on the drop test equipment or the substrate-securing jig.
Accordingly, this standard does not prescribe the drop test equipment, the structure of the jig, or its form
Correlation of a test result with the device and equipment type is straightforward since the test results are
quantified in terms of the strain values. However, details of the device and equipment should be recorded.
6.2 Example of drop test equipment
The drop test equipment is designed to drop a substrate-securing jig with a protrusion on its
base, from a specified height onto a collision plane to apply the impact that would result from
a free fall or similar situation (Figure 1).

60749-40  IEC:2011 – 9 –
Arm
Screw
Hanging wire Test Substrate
-securing jig
substrate
Base plate Component
Base plate
Collision part
Strike surface
Strike surface
Example of test equipment Example of substrate securing jig
IEC  1619/11
Figure 1 – Example of drop test equipment and substrate securing jig
6.3 Example of substrate-securing jig
Unless otherwise specified, the substrate-securing jig shall be constructed to allow the
attachment of the test substrate with screws, and give a drop impact to the solder joints. The
test substrate is fixed so that the device is in the centre of the substrate-securing jig. Unless
otherwise specified, the colliding interface shall be a hemispherical protrusion as shown in
Figure 1 in order to obtain the reproducibility of strain. However, this is not mandatory if
appropriate repeatability can be obtained by another method.
6.4 Example of distance between supporting points
The distance between the supporting points shall be in accordance with the relevant
specification. The recommended distance between supporting points is 50 mm to 80 mm for a
mobile phone (see 6.9.4).
6.5 Example of impacting surface
Unless otherwise specified, the drop test shall be performed on a flat concrete or steel plate
floor.
NOTE Since destruction of the concrete or deformation of the steel plate might be caused by repetitive impacts, it
is desirable to check the surface of floor at each test. When a steel plate floor is used, hardened-steel plate is
recommended in order to prevent deformation due to impact.
6.6 Strain gauge
Unless otherwise specified, the strain gauge shall satisfy following:
a) the gauge length shall be from 1 mm to 2 mm.
b) the strain gauge shall be a foil-type gauge.
c) the strain gauge shall be of a single-axis type.
6.7 Strain gauge attachment
Attach the strain gauge to the test substrate as shown in Figure 2. The strain gauge is
attached to the extension of a corner land central line in the vicinity of the device, taking care
not to stick the gauge on the substrate wiring.

– 10– 60749-40  IEC:2011
NOTE 1 If attachment is difficult, the substrate can be made smooth with the emery paper etc. It is better to apply
adhesives thinly so that cracking and peeling of the interfaces do not occur in during the drop test.
NOTE 2 Test results can differ depending upon the strain gauge attachment method. Refer to Annex B (example
of strain gauge attachment procedure).
NOTE 3 Strain can differ depending upon the strain gauge attachment position on the test board. Therefore, it is
necessary to adjust the position on the board to that of the actual electronic device.

Guide mark
Ball grid alignment
Test substrate
Strain gauge
Substrate-securing jig
Package-outer
shape
IEC  1620/11
Figure 2 – Position of strain gauge attachment
6.8 Strain measurement instrument
The strain measurement instrument used during the drop test shall have sampling rate that is
higher than 150 kHz. When the sampling rate of an instrument is low, strain values and strain
wave patterns are not shown correctly because the peak value of the maximum strain
sometimes cannot be picked up. Therefore, an instrument that has higher sampling rate than
150 kHz is desirable (Figure 3 and Figure 4). However, a sampling rate that is lower than
150 kHz is acceptable if the measuring result is otherwise correctly assured.

60749-40  IEC:2011 – 11 –
Daisy chain
Momentary interruption detector
Bridge circuit
Device
Strain amplifier
Test substrate Strain gauge
Oscilloscope
IEC  1621/11
Figure 3 – Strain measurement instrument

Signal of Daisy chain
Extremely short electrical discontinuity
瞬断した様子（電圧降下）
Strain(+)
＋ひずみ（引張り）
Waveform of strain
Strain(–)
－ひずみ（圧縮）
20 ms/div
20ms ec div
／
IEC  1622/11
Figure 4 – Waveform of strain and electrical conductivity of daisy chain
6.9 Test condition
6.9.1 Drop test conditions
The method and conditions of the drop test shall be specified in the relevant specification.
6.9.2 Test procedure
The drop test method shall be natural free fall.
6.9.3 Drop height
The drop shall be defined in accordance with 6.9.4 by using a strain gauge set on the test
substrate.
– 12– 60749-40  IEC:2011
6.9.4 Pre-test characterization
6.9.4.1 Strain gauge attachment
Attach the strain gauge to the test substrate as shown in Figure 2 and Annex B. The gauge
shall be attached to test surface on which the specimen device is mounted, at a location in
the vicinity of the device.
6.9.4.2 Test substrate attachment
The test substrate shall be attached to the substrate-securing jig with its device side facing
downward.
6.9.4.3 Adjustment of drop height
The substrate-securing jig shall then be raised to the height specified in the relevant
specification and dropped on to the strike surface while measuring the strain level and pulse
duration. Multiple drops maybe required while adjusting the drop height to achieve the
specified strain level and pulse duration. The amount of strain level specified in the relevant
specification shall be consistent with the value measured by the actual application. The peak
value of pull-strain (+ strain) of the wave pattern is considered as the maximum strain. If there
are several kinds of test sample, a drop height is determined by measuring each test sample.
However, if the test samples are the same, it is not necessary to measure all samples.
6.9.4.4 Adjustment of pulse duration
There is a correlation between the drop test life time and the pulse duration of the strain as
shown in Figure 5. There is also a correlation between the distance between the supporting
points and the pulse duration of the strain as shown in Figure 6. It is therefore necessary to
adjust the pulse duration to be consistent with such correlation, and to that of an actual
electronic device pulse duration.
NOTE The pulse duration of a mobile phone is seen to be 0,5 ms to 1,7 ms. Therefore the recommended pulse
duration is set to 1,0 (± 0,5) ms for a mobile phone it is also desirable to adjust the pulse duration so that the
distance between supporting points is 50 mm to 80 mm.

60749-40  IEC:2011 – 13 –
0,6
0,4
Thickness of substrate = 1,27 mm
0,5  BGA 0,65mm pitch
BGA 1,0mm pitch
0,3
BGA 0,8mm pitch
0,4
Solder: Pb-free
0,2 0,3
0,2
The strain failed by
the drop once is
Pulse duration
0,1
defined as limit of  4,0 ms
0,1
1,9 ms
maximum strain
0,8 ms
0,0
0,1 1,0 10
1 10 100 1 000
Pulse duration  (ms)
IEC  1623/11
IEC  1624/11
Figure 5a – Number of times of drop to failure
Figure 5b – Pulse duration
Figure 5 – Correlation strain and number of failures and strain and pulse duration

Thickness of substrate = 0,8 mm

Distance between
1,2
supporting points
Device A
Device B
0,8
C
Device
Test board
Screw
Simulation
Strain gauge
0,4
Base plate
Collision part
IEC  1626/11
0 20 40 60 80 100
Distance between supporting points (mm)
IEC  1625/11
Figure 6 – Correlation between pulse duration
and distance between supporting points
6.9.4.5 Drop test
The drop test shall be carried out after adjusting drop height.
NOTE 1 There is a correlation between the number of times to failure and the maximum strain. The number of
times to failure can be presumed to be the arbitrary maximum strain (Figure 7).

Maximum strain (%)
Pulse duration (ms)
Limit of maximum strain (%)
– 14– 60749-40  IEC:2011
Strain by drop test
■
Arbitrary maximum strain
Number of drops of presumed failure
Number of times of drop to failure
Estimation of a drop test life
IEC  1627/11
Figure 7 – Correlation between the number of times
of failure and the maximum strain
NOTE 2 As an alternative method of deriving strain, the method shown in Annex A (dropping a test rod) may be
used.
6.9.5 Direction
The test substrate shall be attached to the substrate-securing jig with its device side facing
downwards as shown in Figure 8.
Test substrate
Device
IEC  1628/11
Figure 8 – Direction of dropping
6.9.6 Number of drops
The board shall be dropped to destruction or 20 times, whichever is earlier.
7 Summary
The following shall be detailed in the relevant specification:
a) Specification of test substrate (see 5.2)
b) Specification of solder paste (see 5.3)
c) Mounting method and conditions (see 5.4)
d) Specification of pre-conditioning, if required. (see 5.5)
Maximum strain
60749-40  IEC:2011 – 15 –
e) Specification of initial measurement (see 5.6)
f) Test method. The test method shall be selected from this test method (Clause 6) or the
test method in Annex A (see Clause 6 or Annex A)
g) Final measurement (see 5.8)
h) Distance between supporting points (see 6.4 or A.2)
i) Drop height by adjustment (see 6.9.4 or A.3.4)
j) Pre-test characterisation, strain level and pulse duration (see 6.9.4 or A.3.4)

– 16– 60749-40  IEC:2011
Annex A
(normative)
Drop impact test method using test rod

A.1 Equipment
The drop impact test equipment is equipped with a mechanism that is able to drop a test rod
(e.g., metal rod), from a specified height onto the back surface of test substrate in order to
apply the impact that would result from a free fall or similar situation. An outline of the test
apparatus is shown in figure A.1
The test equipment consists of:
a) a substrate securing-jig
b) the mechanism for measuring the substrate surface strain measurement at the time of a
rod fall
c) the mechanism to stabilize the rod fall position
d) the mechanism for eliminating ‘bounce’ so that the rod only strikes once per drop
NOTE A method of fixing the rod in its horizontal plane is recommended.
A.2 Substrate securing-jig
The test substrate shall be fixed to the substrate-securing jig (by bolts or other method) as
follows:
a) the distance between supporting points shall be variable in order to adjust the strain pulse
duration.
b) the test substrate shall be attached with bolts (direct attachment or indirect attachment
using plates) or other method that produces reproducibility of strain.
c) The tip of a rod shall be processed into the shape of a hemisphere (e.g., R = 3 mm) so
that the angling at the tip of the rod does not make contact when the test board bends.

Rod
Collision by drop
Substrate
Test substrate -securing jig
Component
IEC  1629/11
Figure A.1 – Outline of test apparatus

60749-40  IEC:2011 – 17 –
A.3 Test condition
A.3.1 Test condition requirements
The test shall be carried out in accordance with the relevant specification.
A.3.2 Fall method
The rod shall fall naturally and the set up shall be determined by using the strain
measurement pre-test of A.3.4
A.3.3 Drop height of the rod
The fall height is determined using the strain gauge attached to the substrate during the pre-
test of A.3.4.
A.3.4 Adjustment requirements to the fall height of the rod
A.3.4.1 Strain gauge attachment
Attach the strain gauge to the test substrate. The gauge shall be attached to the surface on
which the specimen component is mounted, at the location shown in Figure A.2.
A.3.4.2 Test substrate attachment
The test substrate shall be attached to the substrate-securing jig with its component side
facing downward.
A.3.4.3 Characterization
Using a reserve sample, the fall height of the rod and the distance between supporting points
are adjusted so that they may meet the target substrate surface strain and strain pulse
duration. The test level, with respect to strain, is defined in the individual specification. The
strain defined by the individual specification needs to be in accordance with the value
measured by actual products.
NOTE A pulse duration of 1,0ms or less is recommended (refer to 6.9.4).
If there are several kinds of test sample, a drop height is determined by measuring each test
sample. However, if the test samples are the same, it is not necessary to measure all samples

– 18– 60749-40  IEC:2011
A.3.4.4 Test
The rod is repeatedly dropped after the preliminary test for strain measurement of A.3.4.1 to
A.3.4.3 above from the height adjusted by repeating A.3.4.3.

0,6
0.0.66
Strain (+)
時時時時時時時時 ((時時時時時時)) Strain
時時時時時時時時時時
Conductivity
時時時時時時時時
0,4 4
0.0.44 44
Monentary
時時時時時時時時時時時時 ((時時時時時時時時 ))
interruptions
0,2 2
0.0.22 22
0,0 0
0.0.00 00
Strain (–)
時時時時時時時時 ((時時時時 ))
–2
–0,2
--0.0.22 --22
--–222 000 222 444 666 888 101010
時時 T時時時時ime((msms  (m)) s)
IEC  1630/11
Figure A.2 – Waveform of strain and electrical
conductivity of a daisy chain
Strain  (%)
時時時時時時時時時時時時時時時時((%)%)
時時時時時時時時時時((VV))
Conductivity  (%)
60749-40  IEC:2011 – 19 –
Annex B
(informative)
An example of strain gauge attachment procedure

B.1 Object
This annex provides an example of strain gauge attachment to ensure the correct
measurement of the value of the strain is generated when the samples are subject to drop
impact.
B.2 Equipment and materials
The equipment and materials for strain gauge attachment are shown in Figure B.1. The
adhesive type indicated below must be used to attach the strain gauge. When any other type
of adhesive is used, separate evaluation work is required.

Strain gauge Adhesive dedicated to the strain gauge

(Polyimide carrier foil gauge) (cyanoacrylate type )

Ethanol Cellulose pads
Cellophane Tape
Test substrate
IEC  1631/11
Figure B.1 – Equipment and materials

– 20– 60749-40  IEC:2011
B.3 Strain gauge guide marks
Attach a strain gauge to the side on which the component under test is mounted. The position
at which it is attached shall be 3,25 mm from the centre of the land at a package corner. To
ensure attachment position precision, it is recommended that strain gauge guide marks be
placed. Figure B.2 below shows an example of attaching the strain gauge. For reference, the
dimensions of the guide marks are given.

3 guide marks
on test substrate
2,00 mm
1,80 mm
3,25 mm
0,70 mm
3 center marks
on strain gauge
0,75 mm
IEC  1632/11
Figure B.2 – Example of Attaching Strain Gauge and Guide Mark Dimensions
B.4 Strain gauge attachment procedure
The strain gauge attachment procedure is described below in Figure B.3 and Figure B.4.

60749-40  IEC:2011 – 21 –
Step 1 Dividing the substrate

Using a router, divide the substrate into sections whilst ensuring no

stress is applied to the substrate.

IEC  1633/11
Step 2 Cleaning the board surface

Using the cellulose pads moistened with ethanol, clean the location

where the strain gauge is to be attached (on the side where mounting

takes place), ensuring no stress is applied to the attachment location.

IEC  1634/11
Step 3 Attachment using cellophane tape (1)

Attach a strain gauge to cellophane tape, then position and attach the

strain gauge onto the substrate temporarily, ensuring that the tape is

not too ‘sticky’ so as to prevent its removal.

IEC  1635/11
Step 4 Attachment using cellophane tape (2)

Tear back the strain gauge together with cellophane tape until the back

of the strain gauge is visible.

IEC  1636/11
Figure B.3 – Strain gauge attachment procedure, part 1

– 22– 60749-40  IEC:2011
Step 5 Attaching the strain gauge (1)

Apply a drop of the recommended adhesive to the back of the strain

gauge.
IEC  1637/11
Step 6 Attaching the strain gauge (2)

Attach the strain gauge, squeezing the adhesive between the gauge and

the substrate with the index finger; then, still holding it, nip the tape and

continue to hold the substrate for 10 seconds or more.

[Caution]
Make sure that no adhesive flows onto the component package.

IEC  1638/11
Step 7 Hardening of adhesive
When one minute or more has elapsed, tear off the cellophane tape

slowly. Leave the substrate at room temperature for one hour or more for

the adhesive to harden completely.

[Caution]
Be careful to not damage the connection of the lead wire to the gauge.

IEC  1639/11
Figure B.4 – Strain gauge attachment procedure, part 2
Each strain gauge has its specific gauge factor. A true strain value can be obtained by
compensating the reading with the gauge factor. Usually, a strain value can be compensated
by entering the gauge factor into the measuring instrument.
The following is the compensation expression:
 2,00 
True strain value = × Reading       (B.1)
 
Gauge factor of the strain
 
_____________
– 24 – 60749-40  CEI:2011
SOMMAIRE
AVANT-PROPOS . 26
1 Domaine d’application . 28
2 Références normatives . 28
3 Termes et définitions . 28
4 Équipements d’essai . 29
5 Procédure d’essai . 29
5.1 Spécimen d’essai . 29
5.2 Substrat d’essai . 29
5.3 Pâte à souder . 30
5.4 Méthode de montage . 30
5.5 Préconditionnement. 30
5.6 Mesures initiales . 30
5.7 Mesure intermédiaire . 30
5.8 Mesure finale . 30
6 Méthode d’essai . 30
6.1 But de la méthode d’essai . 30
6.2 Exemple d’équipement d’essai de chute . 30
6.3 Exemple de gabarit de fixation de substrat . 31
6.4 Exemple de distance entre points de soutien . 31
6.5 Exemple de surface de collision . 31
6.6 Jauge de contrainte . 31
6.7 Fixation de la jauge de contrainte . 31
6.8 Instrument de mesure de contrainte . 32
6.9 Conditions d’essai . 33
6.9.1 Conditions d'essai de chute . 33
6.9.2 Procédure d’essai .
...