prEN IEC 61191-10-2:2026

• Status: Not Published
• Publication Date: 25-Jan-2028
• ICS: 31.180 - Printed circuits and boards
• ICS: 31.190 - Electronic component assemblies
• Technical Committee: CLC/SR 91 - Electronics assembly technology
• Current Stage: 4020 - Enquiry circulated - Enquiry
• Start Date: 21-Aug-2026
• Due Date: 29-May-2026
• Completion Date: 21-Aug-2026
• Ref Project: oSIST prEN IEC 61191-10-2:2026 - Circuit board assemblies - Part 10-2 : Guideline for Establishing Bonding Parameters in Laser-Assisted Bonding between Semiconductor Chip and Substrate

prEN IEC 61191-10-2:2026 is an IEC/CENELEC draft for circuit board assemblies. It gives a procedure for establishing bonding parameters in laser-assisted bonding (LAB) between a semiconductor chip and a substrate, using time-temperature measurements, process trials, and inspection results. Engineers, process owners, and quality teams use it to set up LAB conditions for flip-chip packaging and to record the chosen laser settings.

What does prEN IEC 61191-10-2:2026 specify?

prEN IEC 61191-10-2:2026 specifies a method for setting bonding parameters in LAB by measuring time-temperature profiles in flip-chip packaging technology. Clause 1 also notes that LAB can be used in other processes such as LED bonding, solar-cell bonding, and hermetic sealing of MEMS components.

The document is organized into clauses 1 to 7, plus one informative annex and a bibliography.

Annex	What it covers
Annex A	An informative example of establishing bonding parameters, including sample materials, temperature profiles, inspection results, and void data

What are the key requirements of prEN IEC 61191-10-2:2026?

prEN IEC 61191-10-2:2026 focuses on how to find the lowest laser setting that gives acceptable solder joints. The workflow is practical: measure temperature first, then run bonded samples without the thermocouple, then inspect the joints and document the result.

Test set-up and equipment

Clause 4 describes the LAB equipment and the basic materials. The laser source is a near-infrared diode laser with output power above 200 W in continuous-wave mode, wavelength 980 nm, and a uniform irradiation area above 100 mm². The process also uses a thermocouple, an NCA dispenser, a flip-chip die, and a substrate with solder balls.

This matters because the equipment and beam conditions affect how quickly the solder reaches melting temperature and how uniform the heating is. Clause 4 also notes that the thermocouple size affects measurement speed and accuracy, and that the smallest thermocouple is preferred.

Procedure for setting bonding parameters

Clause 5 divides the work into three steps: prepare a sample with a thermocouple, record temperature profiles at different laser powers, and then process samples without the thermocouple for later inspection. The sample preparation step uses a stage temperature of 80 °C, laser irradiation time of 3 s, and bonding pressure of 5 N.

Clause 5 also specifies how to place NCA, position the chip and substrate, insert the thermocouple, and set the homogenizer 10 mm from the chip. For temperature profiling, the document uses laser powers from 50 W to 100 W and cooling time between measurements. In practice, this gives the process engineer the data needed to see which power levels reach solder melting without excessive heating.

Analysis, acceptance, and reporting

Clause 6 says to inspect samples without thermocouples by X-ray and visual inspection after laser bonding. It points to BGA solder-joint assessment criteria that cover ball alignment, electrical clearance, solder connection shape, and voiding. The document uses the lowest laser power that still produces acceptable solder joints.

Clause 7 lists what the test report shall include: test date, identification and dimensions of the die and substrate, laser-bonding machine details, thermocouple details, inspection results with images, recommended output, and the name of the person who conducted the test. This makes the process repeatable and easier to compare across batches or machines.

What terms does prEN IEC 61191-10-2:2026 define?

• Laser assisted bonding (LAB) - A bonding method where uniform laser irradiation heats the component so the solder melts and bonds the component to the substrate.
• Non-conductive adhesive (NCA) - An adhesive used in LAB to support mechanical and chemical joining without electrical conductivity; it is commonly used as flux and underfill in flip-chip LAB.
• Homogenizer - An optical device that reduces variations in a laser beam profile so the output is more uniform.
• Thermocouple - A temperature sensor used here to record the time-temperature profile during LAB trials.
• Time-temperature profile - The temperature rise over time during laser irradiation, used to judge whether the solder reaches melting conditions.
• BGA - Ball Grid Array, the solder-joint type used in the acceptance discussion for alignment, clearance, connection shape, and voiding.

Who uses prEN IEC 61191-10-2:2026?

prEN IEC 61191-10-2:2026 is used in electronics assembly and semiconductor packaging work, especially where flip-chip parts are bonded to substrates. Typical users are process engineers, manufacturing engineers, test engineers, and quality engineers who need to tune laser power, irradiation time, and inspection criteria.

It is also relevant to equipment suppliers and labs that set up laser-bonding machines, thermocouple measurements, X-ray inspection, and optical microscopy for process development or batch qualification.

What changed in prEN IEC 61191-10-2:2026 from the previous edition?

prEN IEC 61191-10-2:2026 supersedes 91/2055/CD and 91/2093/CC.

Which standards are used with prEN IEC 61191-10-2:2026?

No normative references are listed in the document. For joint evaluation, the analysis section and bibliography cite IEC 61191-6, IEC TR 61191-8, and IPC-A-610.

IEC 61191-6 contributes void evaluation criteria and a measurement method for BGA and LGA solder joints. IEC TR 61191-8 provides best practices for voiding in solder joints used in automotive electronic control units. IPC-A-610 is cited for acceptability of electronic assemblies.

What does the prEN IEC 61191-10-2:2026 document contain?

The document includes a laser-bonding machine figure, a test setup figure, thermocouple sample figures, and a procedure broken into sample preparation, temperature-profile recording, and uninstrumented trials. Table 1 gives the BGA solder-joint acceptance criteria used in analysis.

Annex A gives an informative worked example with sample chip and substrate materials, temperature profiles versus laser power, microsection images, X-ray images, and void results. That annex is useful for understanding how the procedure is applied in practice and what kind of output the process yields.

SLOVENSKI STANDARD
01-oktober-2026
Sestavi plošč tiskanih vezi - 10-2.del: Smernice za določanje parametrov spajanja
pri lasersko podprtem spajanju med polprevodniškim čipom in substratom
Circuit board assemblies - Part 10-2 : Guideline for Establishing Bonding Parameters in
Laser-Assisted Bonding between Semiconductor Chip and Substrate
Ta slovenski standard je istoveten z: prEN IEC 61191-10-2:2026
ICS:
31.180 Tiskana vezja (TIV) in tiskane Printed circuits and boards
plošče
31.190 Sestavljeni elektronski Electronic component
elementi assemblies
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

91/2120/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 61191-10-2 ED1
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2026-08-21 2026-11-13
SUPERSEDES DOCUMENTS:
91/2055/CD, 91/2093/CC
IEC TC 91 : ELECTRONICS ASSEMBLY TECHNOLOGY
SECRETARIAT: SECRETARY:
Japan Mr Osamu IKEDA
OF INTEREST TO THE FOLLOWING COMMITTEES: HORIZONTAL FUNCTION(S):
TC 40,TC 47,SC 47A,SC 47D
ASPECTS CONCERNED:
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft
for Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.
This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of
which they are aware and to provide supporting documentation.
Recipients of this document are invited to submit, with their comments, notification of any relevant “In Some
Countries” clauses to be included should this proposal proceed. Recipients are reminded that the CDV stage is
the final stage for submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
Circuit board assemblies - Part 10-2 : Guideline for Establishing Bonding Parameters in Laser-
Assisted Bonding between Semiconductor Chip and Substrate

PROPOSED STABILITY DATE: 2032
NOTE FROM TC/SC OFFICERS:
download this electronic file, to make a copy and to print out the content for the sole purpose of preparing National
Committee positions. You may not copy or "mirror" the file or printed version of the document, o r any part of it,
for any other purpose without permission in writing from IEC.

IEC CDV 61191-10-2 © IEC 2026
1 CONTENTS
3 FOREWORD . 3
4 INTODUCTION . 5
5 1 Scope . 6
6 2 Normative references . 6
7 3 Terms and definitions . 6
8 3.1 laser assisted bonding . 6
9 3.2 non-conductive adhesive . 6
10 3.3 homogenizer . 6
11 4 Materials and equipment . 6
12 5 Procedure . 8
13 5.1 General . 8
14 5.2 Preparing sample for temperature measurement . 8
15 5.3 Recording of temperature profiles with thermocouple-attached sample . 10
16 5.4 Running samples without thermocouple . 10
17 6 Analysis and Establishing Bonding Parameters . 11
18 7 Report . 11
19 Annex A (informative) . 12
20 A.1 General . 12
21 A.2 Sample materials . 12
22 A.3 Establishing Bonding Parameters . 12
23 Bibliography . 16
25 Figure 1 – Laser bonding machine . 7
26 Figure 2 – Substrate before and after NCP application . 8
27 Figure 3 – Test set up . 9
28 Figure 4 – Sample with thermocouple . 9
29 Figure 5 – Laser bonding of sample with thermocouple . 10
30 Figure A.1 – Temperature profile according to power . 13
31 Figure A.2 – Cross-section pictures of bonded samples (70-100W) . 14
32 Figure A.3 – X-ray pictures of bonded samples with voids (70-100W) . 14
34 Table 1 – Requirements for Ball Grid Array Solder Joints . 11
35 Table A.1 – Gradient values according to irradition time . 13
36 Table A.2 – Voids according to irradition time . 15
IEC CDV 61191-10-2 © IEC 2026
43 INTERNATIONAL ELECTROTECHNICAL COMMISSION
44 ____________
46 CIRCUIT BOARD ASSEMBLIES–
48 Part 10-2: Guideline for Establishing Bonding Parameters in Laser-
49 Assisted Bonding between Semiconductor Chip and Substrate
52 FOREWORD
53 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
54 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
55 co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
56 in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
57 Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC Publication(s)"). Their
58 preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
59 may participate in this preparatory work. International, governmental and non-governmental organizations liaising
60 with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
61 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
62 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
63 consensus of opinion on the relevant subjects since each technical committee has representation from all
64 interested IEC National Committees.
65 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
66 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
67 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
68 misinterpretation by any end user.
69 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
70 transparently to the maximum extent possible in their national and regional publications. Any divergence between
71 any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
72 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
73 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
74 services carried out by independent certification bodies.
75 6) All users should ensure that they have the latest edition of this publication.
76 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
77 members of its technical committees and IEC National Committees for any personal injury, property damage or
78 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
79 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
80 Publications.
81 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
82 indispensable for the correct application of this publication.
83 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
84 rights. IEC shall not be held responsible for identifying any or all such patent rights
85 IEC 6XXXX has been prepared by subcommittee WG10 of IEC technical committee 91:
86 Electronics assembly technology. It is an International Standard.
87 The text of this standard is based on the following documents:
Draft Report on voting
91/XX/FDIS 91/XX/RVD
89 Full information on the voting for its approval can be found in the report on voting indicated in
90 the above table.
91 The language used for the development of this International Standard is English.
IEC CDV 61191-10-2 © IEC 2026
92 This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
93 accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement available
94 at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
95 described in greater detail at www.iec.ch/publications.
96 The committee has decided that the contents of this document will remain unchanged until the
97 stability date indicated on the IEC website under webstore.iec.ch in the data related to the
98 specific document. At this date, the document will be
99 • reconfirmed,
100 • withdrawn,
101 • replaced by a revised edition, or
102 • amended.
105 The National Committees are requested to note that for this publication the stability date is 20
106 XX.
107 THIS TEXT IS INCLUDED FOR THE INFORMATION OF THE NATIONAL COMMITTEES AND
108 WILL BE DELETED AT THE PUBLICATION STAGE.
IEC CDV 61191-10-2 © IEC 2026
124 INTRODUCTION
125 In modern flip-chip packaging technology, the increasing number of input/output (I/O) terminals leads
126 to a reduction in pitch, which poses greater challenges with respect to package warpage issues.
127 Thermal compression bonding (TCB) has been used extensively in flip-chip interconnection
128 technology since conventional mass reflow techniques can induce reliability problems due to warpage
129 caused by coefficient of thermal expansion (CTE) mismatches between the semiconductor die and
130 substrate.
131 Although TCB is effective, its productivity is limited because it is a one-by-one process that takes
132 several seconds per bond. To enhance productivity while addressing warpage, a novel bonding
133 technology known as laser-assisted bonding (LAB) has been developed and implemented for
134 advanced flip-chip interconnections.
135 LAB utilizes laser irradiation to heat the component locally, allowing rapid solder reflow with minimal
136 substrate distortion. This approach enables improved throughput and reliability compared with
137 conventional thermal bonding methods.
IEC CDV 61191-10-2 © IEC 2026
140 CIRCUIT BOARD ASSEMBLIES–
142 Part 10-2: Guideline for Establishing Bonding Parameters in Laser-
143 Assisted Bonding between Semiconductor Chip and Subs
...