EN IEC 60749-22-1:2026

SLOVENSKI STANDARD
01-marec-2026
Nadomešča:
SIST EN 60749-22:2004
Polprevodniški elementi - Metode za mehansko in klimatsko preskušanje - 22-1.
del: Moč vezi - Preskusne metode za vlečenje žične vezi (IEC 60749-22-1:2025)
Semiconductor devices - Mechanical and climatic test methods - Part 22-1: Bond
strength - Wire bond pull test methods (IEC 60749-22-1:2025)
Halbleiterbauelemente - Mechanische und klimatische Prüfverfahren –Teil 22:
Kontaktfestigkeit - Drahtbond-Zugprüfverfahren (IEC 60749-22-1:2025)
Dispositifs à semiconducteurs - Méthodes d’essais mécaniques et climatiques - Partie 22
-1: Robustesse des contacts soudés - Méthodes d’essais d’arrachement par traction des
contacts soudés par fil (IEC 60749-22-1:2025)
Ta slovenski standard je istoveten z: EN IEC 60749-22-1:2026
ICS:
19.020 Preskuševalni pogoji in Test conditions and
postopki na splošno procedures in general
31.080.01 Polprevodniški elementi Semiconductor devices in
(naprave) na splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60749-22-1

NORME EUROPÉENNE
EUROPÄISCHE NORM January 2026
ICS 31.080.01 Supersedes EN 60749-22:2003 (partially)
English Version
Semiconductor devices - Mechanical and climatic test methods -
Part 22-1: Bond strength - Wire bond pull test methods
(IEC 60749-22-1:2025)
Dispositifs à semiconducteurs - Méthodes d'essais Halbleiterbauelemente - Mechanische und klimatische
mécaniques et climatiques - Partie 22-1: Robustesse des Prüfverfahren - Teil 22: Kontaktfestigkeit - Drahtbond-
contacts soudés - Méthodes d'essais d'arrachement par Zugprüfverfahren
traction des contacts soudés par fil (IEC 60749-22-1:2025)
(IEC 60749-22-1:2025)
This European Standard was approved by CENELEC on 2025-12-31. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60749-22-1:2026 E

European foreword
The text of document 47/2954/FDIS, future edition 1 of IEC 60749-22-1, prepared by TC 47
"Semiconductor devices" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 60749-22-1:2026.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2027-01-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2029-01-31
document have to be withdrawn
This document, together with EN IEC 60749-22-2:2026, supersedes EN 60749-22:2003.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
This document is read in conjunction with EN IEC 60749-22-2:2026.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 60749-22-1:2025 was approved by CENELEC as a
European Standard without any modification.
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60749-22-2 - Semiconductor devices - Mechanical and - -
climatic test methods - Part 22-2: Bond
strength - Wire bond shear test methods

IEC 60749-22-1 ®
Edition 1.0 2025-11
INTERNATIONAL
STANDARD
Semiconductor devices - Mechanical and climatic test methods -
Part 22-1: Bond strength - wire bond pull test methods
ICS 31.080.01  ISBN 978-2-8327-0861-3

IEC 60749-22-1:2025-11(en)
IEC 60749-22-1:2025 © IEC 2025
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Apparatus and material . 11
4.1 Inspection equipment . 11
4.2 Workholder . 11
4.3 Wire bond pull equipment . 11
4.4 Pulling hook . 11
4.5 Bond pull clamp . 12
5 Procedure . 12
5.1 Calibration . 12
5.2 Visual examination of bonds to be tested after decapsulation . 12
5.2.1 Applicability . 12
5.2.2 Bond pad examination and acceptability criteria for both aluminium and
copper bond pad metallization . 13
5.2.3 Examination and acceptability criteria for Cu and Ag wire and
connections (all bonds) . 13
5.3 Performing the wire bond pull test . 13
5.3.1 Wire bond pull test used . 13
5.3.2 Hook pull method . 13
5.3.3 Clamp pull method of single bond (cut wire) . 21
5.4 Examination of pulled wire bonds . 23
5.5 Wire bond pull failure codes . 24
5.5.1 Tabulation of codes . 24
5.5.2 Defining code 6 versus Code 7 for thermosonic stitch bonds . 31
5.5.3 Discussion on the significance of failure codes. 32
5.6 Wire bond pull data . 33
5.6.1 Recording wire bond pull data . 33
5.6.2 Determining equivalent wire diameter for ribbon bonds . 33
5.6.3 Effective pull force versus the actual force on a bond . 34
6 Summary . 34
Annex A (informative) Guidance for performing pull testing on stacked bonds
(reverse, security and others) . 35
A.1 Reverse bonds . 35
A.2 Security bonds . 37
A.3 Other stacked bonds . 37
Annex B (informative) Guidance for performing decapsulation on devices prior to bond
pull testing . 39
B.1 Rationale . 39
B.2 Warning regarding ultrasonic cleaning of exposed wire bonds . 39
B.3 Concerns with decapsulation processes for devices with copper and silver

wire bonds . 39
B.4 Concern with undercutting bonds due to over etching of the silver plating on
leadframes . 41
B.5 Techniques for assessing if excessive etching of ag plating has occurred . 43
B.6 Concern with decapsulating packages with stitch bonds on multiple planes . 44
IEC 60749-22-1:2025 © IEC 2025
B.7 Concern with not removing all encapsulation material around the bonded
wire prior to pull testing . 45
Annex C (informative) Correlation between pull failure codes in this document versus
pull failure codes in Mil-Std 883, Method 2011.9 . 46
Annex D (informative) Images to aid in determining appropriate failure codes . 48
D.1 Ilustration of failure codes . 48
D.2 Failure in deformed portion of wire above thermosonic stitch bond – Code 6 . 49
D.3 Failure in thermosonic stitch bond – Code 7 . 50
D.4 Additional guidance for breaks in thermosonic stitch bonds – Code 6 versus
code 7 . 51
Annex E (informative) Additional guidance regarding minimum pull force specification
values and process control requirements . 55
Annex F (informative) Factors that can affect wire pull outcome . 56
F.1 Important factors . 56
F.2 How bond angle affects pull force . 57
F.3 Pull angle affects pull force and fail mode . 58
Annex G (informative) Background and reasons for choice of minimum pull
specification values . 60
Bibliography . 61

Figure 1 – Definition of midspan . 9
Figure 2 – Depiction of eight outliers, seven of which are outlier products . 10
Figure 3 – Place hook under wire . 14
Figure 4 – Orientation of hook with respect to the wire (viewed from above) . 14
Figure 5 – Hook placement for wire pull test (WPT) for different types of wire bonds . 16
Figure 6 – Wires with low bond angles . 17
Figure 7 – Device with slots to allow for hook placement . 17
Figure 8 – Reverse "shingle" stack . 18
Figure 9 – Vertical stack of die of the same size . 18
Figure 10 – Hook placement for ball pull test (BPT) for different types of wire bonds . 20
Figure 11 – Hook placement for stitch pull test (SPT) for different types of wire bonds . 21
Figure 12 – Examples of acceptable and unacceptable placement of clamp on wire . 22
Figure 13 – Clamp placement for ball pull test . 23
Figure 14 – Clamp placement for stitch pull test. 23
Figure 15 – General description of wire bond pull failure codes for all bond types . 24
Figure 16 – Detailed pull failure codes for standard thermosonically bonded wires . 25
Figure 17 – Detailed pull failure codes for reverse thermosonically bonded wires . 26
Figure 18 – Detailed pull failure codes for die to die thermosonically bonded wires . 27
Figure 19 – Detailed pull failure codes for standard ultrasonically bonded wires . 28
Figure 20 – Detailed pull failure codes for die to die ultrasonically bonded wires . 29
Figure 21 – Detailed pull failure codes for substrate to substrate ultrasonically bonded
wires . 30
Figure 22 – Detailed pull failure codes for multi-loop ultrasonically bonded wires /
ribbons . 31
Figure 23 – Location of breaks in the stitch neckdown region versus in the stitch bond . 32
Figure A.1 – Top view image of reverse bond . 35
IEC 60749-22-1:2025 © IEC 2025
Figure A.2 – Side view image of reverse bond . 35
Figure A.3 – Examples of different electrical connections made with reverse bonds . 36
Figure A.4 – The bump of a security bond . 37
Figure A.5 – The ball bond of a security loop . 37
Figure A.6 – Example of another type of stacked bonds. 38
Figure B.1 – Images of copper ball bonds showing severe damage from etching
process . 39
Figure B.2 – Comparison images showing degree of cu attack due to two different
etchants . 40
Figure B.3 – Copper wire stitch bond fully decapsulated using laser ablation . 41
Figure B.4 – Laser ablation damage . 41
Figure B.5 – Drawn, optical and SEM images of break where metallurgical bond begins . 42
Figure B.6 – Undercutting of stitch bond due to excessive etching of silver plating . 42
Figure B.7 – Ag plating removed by the decapsulation process, underlying cu is visible . 43
Figure B.8 – Plated Ag visible in the area around the stitch bonds, cu only visible at
edges . 43
Figure B.9 – Assessing if excessive etching of Ag plating has occurred. 44
Figure B.10 – SEM and optical image examples of a reasonable amount of remaining
encapsulant material for pull testing of very low angle bonds . 45
Figure C.1 – Pull failure code locations for this document and Mil-Std 883, Method
2011.9 . 46
Figure C.2 – Failure code diagram from Mil-Std 883, Method 2011.9 . 47
Figure D.1 – Gold stitch bond (unencapsulated) before and after wire pull testing . 49
Figure D.2 – Examples of break occurring within the neckdown region . 49
Figure D.3 – Copper stich bonds before and after wire pull testing . 50
Figure D.4 – SEM image of a break within the neckdown region of a gold stitch bond . 50
Figure D.5 – Break occurring within gold stitch bonds. 50
Figure D.6 – Break occurring within neckdown region of copper stich bonds . 51
Figure D.7 – SEM images of where the breaks are designated code 7 . 51
Figure D.8 – Gold stitch bond on a Ni/Au plated cu land on an organic substrate . 52
Figure D.9 – Images from construction analysis report of gold stitch bond . 52
Figure D.10 – Stitch bonds made with Pd coated Cu wire on a Ag plated Cu alloy
leadframe . 52
Figure D.11 – Ag splash . 53
Figure D.12 – Gaps between Cu wire and NiPdAu plated leadframe . 53
Figure D.13 – Stitch bond made with Cu wire on a Ag plated Cu alloy leadframe. 54
Figure D.14 – Images from construction analysis report of stitch bond made with Cu
wire on a Ag plated Cu alloy leadframe . 54
Figure F.1 – Force diagram and detailed force equations 5.3.4 and 5.3.5 from NBS
Technical note 726 . 56
Figure F.2 – Pull force versus tension in wire, an example of very low bond angles . 57
Figure F.3 – Various bond angles with respect to their bonding surfaces . 58
Figure F.4 – How pull angle affects tension . 59

Table 1 – Guidance for the minimum diameter of the pulling hook . 12
IEC 60749-22-1:2025 © IEC 2025
Table C.1 – Conversion from (new) this document pull codes to (old) Mil-Std 883,
Method 2011.9 . 46
Table D.1 – Failure code illustrations . 48
Table F.1 – Compensation for minimum pull force for various bond angles . 58
Table F.2 – How pull angle Φ affects force applied to each bond . 59

IEC 60749-22-1:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Semiconductor devices - Mechanical and climatic test methods -
Part 22-1: Bond strength - Wire bond pull test methods

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC Publication(s)"). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 60749-22-1 has been prepared by IEC technical committee 47: Semiconductor devices. It
is an International Standard.
This International Standard is to be used in conjunction with IEC 60749-22-2:2025.
This first edition, together with the first edition of IEC 60749-22-2:2025, cancels and replaces
the first edition of IEC 60749-22 published in 2002. It is based on JEDEC document JESD22-
B120. lt is used with permission of the copyright holder, JEDEC Solid State Technology
Association.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Major update, including new techniques and use of new materials (e.g. copper wire)
involving a complete rewrite as two separate subparts (this document and IEC 60749-22-2).
IEC 60749-22-1:2025 © IEC 2025
The text of this International Standard is based on the following documents:
Draft Report on voting
47/2954/FDIS 47/2975/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 60749 series, published under the general title Semiconductor
devices - Mechanical and climatic test methods, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
– reconfirmed,
– withdrawn, or
– revised.
IEC 60749-22-1:2025 © IEC 2025
1 Scope
This part of IEC 60749 provides a means for determining the strength and failure mode of a
wire bonded to, and the corresponding interconnects on, a die or package bonding surface and
can be performed on unencapsulated or decapsulated devices. This test method can be
performed on gold alloy, copper alloy, and silver alloy thermosonic (ball and stitch) bonds made
of wire ranging in diameter from 15 µm to 76 µm (0,000 6" to 0,003"); and on gold alloy, copper
alloy, and aluminium alloy ultrasonic (wedge) bonds made of wire ranging in diameter from
18 µm to 600 µm (0,000 7" to 0,024").
This wire bond pull test method is destructive. It is appropriate for use in process development,
process control, or quality assurance.
This test method allows for two distinct methods of pulling wires:
a) One method incorporates the use of a hook that is placed under the wire and is then pulled.
b) One method requires that after the wire be cut, a clamp is placed on the wire connected to
the bond to be tested, and this clamp is used to pull the wire.
This test method defines three pull tests. The wire pull test (WPT) is appropriate for all bonded
wires. The ball pull test (BPT) and stitch pull test (SPT) are appropriate for thermosonically
bonded wires.
This test method can also be used on the following four applications of thermosonic and
ultrasonic bonds, though each requires special considerations when performing the test
method:
a) Pulling aluminium wires and aluminium ribbons that are bonded with multiple ultrasonic
bonds. See 5.3.2.2.2 for special considerations. Multiloop wires and ribbons are used in
some high-power device packages.
b) Pulling wires of reverse bonds which are also known as "stitch on ball". These types of
bonds can include gold stitch on gold ball, copper stitch on copper ball, and copper stitch
on gold ball. See Clause A.1 in Annex A for additional information.
c) Pulling a thermosonically bonded wire that has a security bond (see 3.9) or security loop
(see 3.19) placed on top of the stitch bond (see 3.3) in order to provide additional strength.
See Clause A.2 for additional information.
d) Pulling thermosonic wire bonds on stacked die when wires or bonds, or both, are not
accessible to allow for proper pull testing. See 5.3.2.2.4 for special considerations
This test method does not include bond strength testing using wire bond shear testing. Wire
bond shear testing is described in IEC 60749-22-2.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60749-22-2, Semiconductor devices - Mechanical and climatic test methods - Part 22-2:
Bond strength testing - Wire bond shear test methods
IEC 60749-22-1:2025 © IEC 2025
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
– IEC Electropedia: available at https://www.electropedia.org/
– ISO Online browsing platform: available at https://www.iso.org/obp
3.1
bond wire
adhesion or welding of a wire (typically gold, aluminium, copper, or silver) to a bonding surface
using a thermosonic or ultrasonic wire bonding process
3.2
ball bond
first bond during the thermosonic (ball) bonding process, in which the end of a small diameter
wire (typically gold, copper, or silver) is bonded to a die bonding surface (typically an aluminium
alloy die pad metallization)
Note 1 to entry: The ball bond includes the enlarged spherical or nail-head portion of the wire that is provided by
the electronic flame-off, the underlying bonding pad, and the metallurgical weld interface between the ball bond and
the bonding pad.
3.3
stitch bond
second bond during the thermosonic (ball) bonding process, in which the wire is typically
bonded to the package bonding surface (e.g. leadframe, substrate, post, etc.)
Note 1 to entry: A stitch bond is also referred to as a crescent bond.
Note 2 to entry: For some unique constructions (e.g. reverse bond), the second bond can be formed on top of a
bump. See also "reverse bond" and "bump".
3.4
wedge bond
attachment of a wire (typically aluminium, copper, or gold) or an aluminium ribbon to a die
bonding surface (typically aluminium pad metallization) or the package bonding surface (usually
a plated leadframe post or finger) using an ultrasonic bonding process
3.5
bonding surface
surface to which the wire is bonded, which can be any one of the following: 1) the die pad
metallization or die surface metallization (e.g., MOSFET), 2) the package surface metallization
(e.g. leadframe, substrate, post), 3) a bump (see also "reverse bond" and "bump"), or 4) a
bonded stitch on die pad/flag or package surface metallization
Note 1 to entry: See also "security bond" and "security loop".
3.6
bonding process
bonding process in which two members are joined through the combined
application of heat, pressure, and an ultrasonic oscillatory lateral motion
3.7
bonding process
bonding process in which two members are joined through the combined
application of pressure and an ultrasonic oscillatory lateral motion
IEC 60749-22-1:2025 © IEC 2025
3.8
bonding wire
wire that is bonded to a chip bonding surface in order to electrically connect the chip to any
other point within the device package
3.9
ribbon
wire that is flat (non-round)
Note 1 to entry: Throughout this test method the term "wire" covers both wire and ribbon (wire).
3.10
aluminium wire
aluminium alloy wire in which the aluminium content is typically 98 % or greater
3.11
copper wire
copper alloy wire in which the copper content is typically 99 %, but also includes copper wire
with a very thin coating of palladium or gold and palladium
3.12
gold wire
gold alloy wire in which the gold content is typically 99 % or greater
3.13
silver wire
silver alloy wire in which the silver content is typically greater than 85 % for integrated circuits
(ICs) and greater than 75 % for light emitting diodes (LEDs)
3.14
midspan
location on the bonded wire that is approximately one half of the horizontal distance between
the two bonds
SEE: Figure 1.
Figure 1 – Definition of midspan
IEC 60749-22-1:2025 © IEC 2025
3.15
outlier product
product that meets manufacturer specifications and user requirements but exhibits anomalous
characteristics with respect to a normal population and can be subject to a higher-than-normal
level of failures in the user's application
Note 1 to entry: An example of anomalous characteristics with respect to a normal population is depicted by the
histogram in Figure 2.
Note 2 to entry: For purposes of this document, all wire bond pull tests have only a minimum pull value requirement
and no upper limit, thus the upper specification limit (USL) is not applicable.
Note 3 to entry: See also JESD50.

Figure 2 – Depiction of eight outliers, seven of which are outlier products
3.16
reverse bond
thermosonic bond for which the ball is placed on the package bonding surface and the stitch is
placed on a bump on the die
Note 1 to entry: This is also known as "stitch on ball".
3.17
bump
thermosonic ball bond from which the wire has been removed
nd
Note 1 to entry: It can be used as the underlying ball bond for reverse bonds on which the stitch (2 bond) for the
reverse bond is placed, or the ball bond placed on a stitch bond to form a security bond.
3.18
security bond
placing of a bump on top of a stitch bond to improve the mechanical strength of a stitch bond
to withstand the shearing stress between the encapsulation material and the bonding surface
Note 1 to entry: Security bonds are commonly used in surface mount LED (light emitting diode) packages which
use non-filled encapsulants for the lens material that have higher coefficients of thermal expansion than silica filled
encapsulants, and thus exhort higher shear stresses on the stitch bond.
3.19
security loop
security bond from which the wire has not been removed and the wire for the security loop is
attached to the same bonding surface as a stitch bond
3.20
wire bond pull
process in which an instrument pulls on a thermosonic or ultrasonic bonded wire
until failure
IEC 60749-22-1:2025 © IEC 2025
3.21
wire bond pull
process in which an instrument pulls on a thermosonic or ultrasonic bonded
wire with a specified load that is below the minimum destructive pull value, such that no
permanent damage or degradation is expected to be imparted on the wire
3.22
wire bond pull force
destructive force required to cause any of the following to occur: the bonded wire
to break; one of the bonds to separate from a bonding surface; or one of the bonding surfaces
to separate from the die, leadframe, or substrate
4 Apparatus and material
4.1 Inspection equipment
An optical microscope system or scanning electron microscope with a minimum of 70X
magnification is required to support the optical assessment of the resulting failure mode, such
as whether the wire break was ductile or brittle or if the bond lifted from the pad, leadframe or
substrate with or without residues on the pad, leadframe or substrate). However, a higher
magnification can be necessary for verifying failure codes 1, 2, 3, 6, 7, 8, and 9 (see 5.5 for a
detailed discussion of failure codes).
4.2 Workholder
The fixture used to hold the device, known as the "workholder", shall prevent any movement of
the device during the wire bond pull testing and shall allow positioning the hook for optimum
force application to the wire.
4.3 Wire bond pull equipment
The apparatus shall consist of equipment for applying a pulling force to the bonding wire as
required in accordance with this test method until failure occurs within the wire, wire bond, or
wire bonding surface. The equipment shall be capable of applying force at a constant rate. The
equipment shall indicate the applied force in SI or English units, or both, and be calibrated over
the full range of the expected values for the specific wire being pulled with an accuracy of ±5 %
of the intended breaking load or ±2,9 mN (± 0,3 gf), whichever is the greater tolerance. The
required range of force values will vary by wire material and wire cross-section.
The pull tester manufacturer's recommended pulling tool travel speed for the wire material being
tested should be used. To verify that the pull speed for a test was in an acceptable range, the
output of the loadcell shall be reviewed to ensure that the strain rate was consistent throughout
the test.
4.4 Pulling hook
The pulling hook should be made of a strong, rigid material that will not deform during pull
testing. The diameter of the wire used to make the hook utilized to apply force to the
interconnect wire shall be large enough and its final shape shall be such to ensure that the
force applied by the hook distributes the pull force through the wire to the bonds and does not
cut through the wire. Table 1 provides the minimum diameter for the pulling hook to ensure the
above requirement.
IEC 60749-22-1:2025 © IEC 2025
Table 1 – Guidance for the minimum diameter of the pulling hook
Wire diameter Hook diameter
≤ 50 µm (0,002") Minimum of 2,0x wire diameter
˃ 50 µm (0,002") to ≤ 125 µm (0,005") Minimum of 1,5x wire diameter
˃ 125 µm (0,005") Minimum of 1,0x wire diameter

For ribbon wire, use the equivalent round wire diameter which gives the same cross-sectional
area as the ribbon wire being tested. The flat portion of the hook (horizontal) should be > 1,25x
the equivalent diameter of the ribbon wire being tested.
The hook shall be smooth (no sharp edges) and free of defects and contamination which could
compromise the test results or damage the wire being pulled.
4.5 Bond pull clamp
For the clamp pull tests, the clamp used shall be able to apply enough force to the wire being
pulled to hold it firmly such that it will not slip during the test. The clamp shall be large enough
to firmly hold the diameter of the wire or width and thickness of the ribbon to be pulled such
that it does not move when being pulled. The external shape and dimensions of the clamp shall
be optimized to allow for it to clamp onto the wire to be pulled, but also minimize the chance of
it touching and possibly damaging other wires on the device that are intended to be pull tested.
5 Procedure
5.1 Calibration
Before performing the wire bond pull test, it shall be determined that the equipment has been
calibrated in accordance with the manufacturer's specifications and is presently in calibration.
Recalibration is required if the equipment is moved to another location.
5.2 Visual examination of bonds to be tested after decapsulation
5.2.1 Applicability
In addition to being a manufacturing process monitor, this test method can also be used to
assess bonds of encapsulated devices after soldering operations or after reliability stress
testing. To do this, the encapsulation material should be removed in a manner that does not
significantly degrade the wire, the bond, the bonding interface, or the bonding surface. Bond
pull force values are often lower for bonds that have been decapsulated, and therefore cannot
be compared to values for similar, unencapsulated bonds. If the decapsulation process is well
controlled and repeatable, which is the case for gold wire, then this test method can be used
for lot-to-lot comparison; however, it can be difficult to consistently control the decapsulation
process for copper and silver wires to ensure the accuracy of the results. For copper (Cu) and
silver (Ag) wires, the effectiveness of etch has been seen to vary due to the encapsulation
material and the level of reliability stress testing performed on the samples. See Annex B for
additional information regarding the decapsulation process of devices with Cu and Ag wire
bonds.
Bonds shall also be examined to ensure that enough encapsulation material has been removed
to allow for suitable placement of the pull hook.
IEC 60749-22-1:2025 © IEC 2025
5.2.2 Bond pad examination and acceptability criteria for both aluminium and copper
bond pad metallization
If performing wire bond pull testing on a device which has been opened using wet chemical or
dry etch techniques, or both, the bond pads shall be examined to initially ensure that there is
no absence of metallization on the bonding surface area due to chemical etching and then
ensure that wire bonds are attached to the bonding surface. Bonds on aluminium or copper
bond pads with significant chemical attack or absence of metallization shall not be used for wire
bond pull testing.
It is possible that wire bonds on bonding surfaces without degradation from chemical attack will
not be attached to the bonding surface due to other causes (e.g. package stress), however, in
these cases wire bonds are considered valid and shall be included in the pull data as a zero (0)
pull force value.
5.2.3 Examination and acceptability criteria for Cu and Ag wire and connections (all
bonds)
When performing wire bond pull testing on a device with copper or silver wires, the connection
of the bond and wire shall be examined after decapsulation, both before or after the pull test to
ensure that there is no significant loss of metal or other damage due to decapsulation process
that might affect the results of the pull test. The pull result can be excluded for a copper bond
or a copper wire with significant chemical attack or other damage due to the decapsulation
process. Annex B provides additional information to assess what level of damage is acceptable.
5.3 Performing the wire bond pull test
5.3.1 Wire bond pull test used
Multiple wire bond pull tests are described in this document:
– wire pull (hook used to pull wire so that both bonds are stressed),
– ball pull (hook or clamp used to stress mainly the ball bond),
– stitch pull (hook or clamp used to stress ma
...