SIST EN 61191-3:2018

SLOVENSKI STANDARD
SIST EN 61191-3:2018
01-februar-2018
1DGRPHãþD
SIST EN 61191-3:2001
6HVWDYLSORãþWLVNDQLKYH]LMGHO3RGURþQDVSHFLILNDFLMD=DKWHYH]DVSDMNDQH
VHVWDYHQDPHãþHQHYVNR]QMLKOXNQMDK
Printed board assemblies - Part 3: Sectional specification - Requirements for through-
hole mount soldered assemblies
Elektronikaufbauten auf Leiterplatten - Teil 3: Rahmenspezifikation - Anforderungen an
gelötete Baugruppen in Durchsteckmontage
Ensembles de cartes imprimées - Partie 3: Spécification intermédiaire - Exigences
relatives à l'assemblage par brasage de trous traversants
Ta slovenski standard je istoveten z: EN 61191-3:2017
ICS:
31.180 7LVNDQDYH]MD7,9LQWLVNDQH Printed circuits and boards
SORãþH
SIST EN 61191-3:2018 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 61191-3:2018

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SIST EN 61191-3:2018


EUROPEAN STANDARD EN 61191-3

NORME EUROPÉENNE

EUROPÄISCHE NORM
September 2017
ICS 31.240 Supersedes EN 61191-3:1998
English Version
Printed board assemblies - Part 3: Sectional specification -
Requirements for through-hole mount soldered assemblies
(IEC 61191-3:2017)
Ensembles de cartes imprimées - Partie 3: Spécification Elektronikaufbauten auf Leiterplatten - Teil 3:
intermédiaire - Exigences relatives à l'assemblage par Rahmenspezifikation - Anforderungen an gelötete
brasage de trous traversants Baugruppen in Durchsteckmontage
(IEC 61191-3:2017) (IEC 61191-3:2017)
This European Standard was approved by CENELEC on 2017-07-04. 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.



European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN 61191-3:2017 E

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SIST EN 61191-3:2018
EN 61191-3:2017
European foreword
The text of document 91/1375/CDV, future edition 2 of IEC 61191-3, prepared by
IEC/TC 91 "Electronics assembly technology" was submitted to the IEC-CENELEC parallel vote and
approved by CENELEC as EN 61191-3:2017.

The following dates are fixed:
(dop) 2018-04-04
• latest date by which the document has to be
implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2020-07-04
standards conflicting with the
document have to be withdrawn

This document supersedes EN 61191-3:1998.

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.

Endorsement notice
The text of the International Standard IEC 61191-3:2017 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 60068-2-20 NOTE Harmonized as EN 60068-2-20.
IEC 60068-2-58 NOTE Harmonized as EN 60068-2-58.
IEC 61188-5-1 NOTE Harmonized as EN 61188-5-1.
IEC 61188-5-2 NOTE Harmonized as EN 61188-5-2.
IEC 61188-5-3 NOTE Harmonized as EN 61188-5-3.
IEC 61188-5-4 NOTE Harmonized as EN 61188-5-4.
IEC 61188-5-6 NOTE Harmonized as EN 61188-5-5.
IEC 61188-7 NOTE Harmonized as EN 61188-7.
IEC 61189-2 NOTE Harmonized as EN 61189-2.
IEC 61190-1-2 NOTE Harmonized as EN 61190-1-2.
IEC 61193-1 NOTE Harmonized as EN 61193-1.
IEC 61193-3 NOTE Harmonized as EN 61193-3.
IEC 62326-1 NOTE Harmonized as EN 62326-1.
IEC 62326-4 NOTE Harmonized as EN 62326-4.

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SIST EN 61191-3:2018
 EN 61191-3:2017
IEC 62326-4-1 NOTE Harmonized as EN 62326-4-1.
ISO 9001 NOTE Harmonized as EN ISO 9001.

3

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SIST EN 61191-3:2018
EN 61191-3:2017

Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
NOTE 1 When 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.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60194 -  Printed board design, manufacture and - -
assembly - Terms and definitions
IEC 61191-1 2013 Printed board assemblies -- Part 1: EN 61191-1 2013
Generic specification - Requirements for
soldered electrical and electronic
assemblies using surface mount and
related assembly technologies
IPC-A-610 -  Acceptability of Electronics Assemblies - -

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SIST EN 61191-3:2018



IEC 61191-3

®


Edition 2.0 2017-05




INTERNATIONAL



STANDARD



















Printed board assemblies –

Part 3: Sectional specification – Requirements for through-hole mount soldered

assemblies


























INTERNATIONAL

ELECTROTECHNICAL


COMMISSION





ICS 31.240 ISBN 978-2-8322-4397-8



  Warning! Make sure that you obtained this publication from an authorized distributor.


® Registered trademark of the International Electrotechnical Commission

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SIST EN 61191-3:2018
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CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 General requirements . 6
5 Through-hole mounting of components . 7
5.1 General . 7
5.2 Placement accuracy . 7
5.3 Through-hole component requirements . 7
5.3.1 Lead preforming . 7
5.3.2 Tempered leads . 7
5.3.3 Lead forming requirements . 7
5.3.4 Stress relief requirements . 8
5.3.5 Lead termination requirements . 8
6 Acceptance requirements . 10
6.1 General . 10
6.2 Control and corrective actions . 10
6.2.1 General . 10
6.2.2 Interfacial connections (vias) . 10
6.3 Through-hole component lead soldering . 11
6.3.1 General . 11
6.3.2 Clinched leads . 12
6.3.3 Exposed basis metal . 13
7 Rework of unsatisfactory solder connections . 13
Annex A (normative) Placement requirements for through-hole mount devices . 14
A.1 General . 14
A.2 Horizontal mounting, free-standing . 14
A.3 Axial lead components . 14
A.4 Radial lead components . 14
A.5 Perpendicular mounting, free-standing . 14
A.5.1 General . 14
A.5.2 Mounting of components . 14
A.5.3 Radial lead components . 15
A.6 Side- and end-mounting . 15
A.7 Supported component mounting . 16
A.7.1 General . 16
A.7.2 Stand-off positioning . 16
A.7.3 Non-resilient footed stand-offs . 17
A.8 Stress relief lead configuration . 17
A.9 Flat pack lead configuration . 17
Bibliography . 19

Figure 1 – Lead bends . 8
Figure 2 – Hole obstruction . 10
Figure 3 – Through-hole component lead soldering . 11

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IEC 61191-3:2017 © IEC 2017 – 3 –
Figure 4 – Lead-to-land fillet requirements for clinched leads and wires in non-plated
through-holes . 11
Figure 5 – Lead-to-land fillet requirements for clinched leads and wires in plated
through-holes . 12
Figure A.1 – Mounting of free-standing components . 14
Figure A.2 – Typical configuration of components with dual non-axial leads . 15
Figure A.3 – Mounting of components with dual non-axial leads . 15
Figure A.4 – Side mounting . 15
Figure A.5 – End mounting. 16
Figure A.6 – Mounting with footed stand-offs . 16
Figure A.7 – Non-resilient footed stand-offs . 17
Figure A.8 – Acceptable lead configurations . 17
Figure A.9 – Configuration of ribbon leads for through-hole mounting . 18

Table 1 – Plated through-holes with component leads, minimum acceptable
1)
conditions . 12
Table 2 – Through-hole solder joint defects . 13

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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

PRINTED BOARD ASSEMBLIES –

Part 3: Sectional specification – Requirements
for through-hole mount soldered assemblies

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC 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) 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 61191-3 has been prepared by WG 2: Requirements for electronics
assemblies, of IEC technical committee 91: Electronics assembly technology.
This second edition cancels and replaces the first edition published in 1998. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) The requirements have been updated to be compliant with the acceptance criteria in
IPC-A-610F.

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SIST EN 61191-3:2018
IEC 61191-3:2017 © IEC 2017 – 5 –
The text of this standard is based on the following documents:
CDV Report on voting
91/1375/CDV 91/1435/RVC

Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 61191 series, published under the general title Printed board
assemblies, 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 "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

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PRINTED BOARD ASSEMBLIES –

Part 3: Sectional specification – Requirements
for through-hole mount soldered assemblies



1 Scope
This part of IEC 61191 prescribes requirements for lead and hole solder assemblies. The
requirements pertain to those assemblies that totally use through-hole mounting technology
(THT), or the THT portions of those assemblies that include other related technologies (i.e.
surface mount, chip mounting, terminal mounting).
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 60194, Printed board design, manufacture and assembly – Terms and definitions
IEC 61191-1:2013, Printed board assemblies – Part 1: Generic specification – Requirements
for soldered electrical and electronic assemblies using surface mount and related assembly
technologies
IPC-A-610, Acceptability of Electronic Assemblies
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60194 apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
THT
through-hole technology
technology that permits an electrical connection of components to a conductive pattern by the
use of plated or non-plated holes with annular rings in the mounting substrate
4 General requirements
Requirements of IEC 61191-1 are a mandatory part of this specification. Workmanship shall
meet the requirements of IPC-A-610 in accordance with the classification requirements of this
document.

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IEC 61191-3:2017 © IEC 2017 – 7 –
5 Through-hole mounting of components
5.1 General
This clause covers the assembly of components with leads inserted into through-holes and
soldered by machine and/or manual processes.
5.2 Placement accuracy
Placement accuracy for components inserted either manually or by machine methods shall be
sufficient to insure that components are properly positioned after soldering. If suitable process
controls are not in place to ensure compliance with this requirement and the intent of Annex
A, the detailed requirements of Annex A shall be applicable.
5.3 Through-hole component requirements
5.3.1 Lead preforming
Part and component leads shall be pre-formed to the final configuration, excluding the final
clinch or retention bend, before assembly or installation.
5.3.2 Tempered leads
When it is necessary to cut tempered leads, the governing work instructions shall specify
cutting tools that do not impart detrimental shocks to internal connections of the components.
5.3.3 Lead forming requirements
Leads shall be formed in such a manner that the lead-to-body seal is not damaged or
degraded. Leads shall extend at least one lead diameter or thickness but not less than
0,8 mm from the body or weld before the start of the bend radius (see Figure 1).
Exposed core metal is acceptable if reduction in the cross-sectional area does not exceed
10 % of the diameter of the lead. Occurrence of exposed core metal in the formed area of the
lead shall be treated as a process indicator.
Measurement shall be made from the end of the part. The end of the part is defined to include
any coating meniscus, solder seal, solder or weld bead, or any other extension.
The span for components mounted with a conventional lead form is 7,6 mm minimum, and
33 mm maximum.

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Straight for 1 diameter/lead thickness, Straight for 1 diameter/lead thickness,
but not less than 0,8 mm but not less than 0,8 mm
R
R


Weld

Diameter thickness
Diameter thickness
IEC IEC



a) Standard bend b) Welded bend

Maximum lead diameter Minimum bend radius
mm R
Up to 0,8 1 diameter/thickness
0,8 to 1,2 1,5 diameters/thicknesses
Larger than 1,2 2 diameters/thicknesses
Figure 1 – Lead bends
5.3.4 Stress relief requirements
Component leads shall be formed in such a manner that the lead compliancy is not restricted
in providing the natural stress relief of the lead material. Special lead formations are permitted
to enhance stress relief properties.
5.3.5 Lead termination requirements
5.3.5.1 General
To ensure part retention during soldering operations, lead terminations in printed board plated
through-holes shall be one of the following configurations: full clinch, partially clinched, or
straight-through lead termination, as specified on the assembly drawing. In the event
that nothing is specified, the manufacturer shall conform to the requirements in 5.3.5.2 to
5.3.5.10 as appropriate.
5.3.5.2 Clinched lead termination
Leads in unsupported holes and class C shall be clinched a minimum of 45°. The lead end
should not extend beyond the edge of the land; however, if overhang does occur, the lead
extension shall not violate minimum electrical spacing requirements. Leads formed of alloy 42
or comparable iron bearing alloys shall not be terminated with a full clinch.
NOTE Alloy 42 has the composition of Fe-Ni 41-Mn 0,8-Co 0,5.
5.3.5.3 Clinched lead orientation
When manually clinched, the clinched portion of the wire or lead should be directed along a
printed conductor connected to the land. The leads on opposite ends or sides of a component
should be directed in opposite directions. When automatically clinched, the orientation of the
clinch relative to any conductor is optional. Manually formed clinches for non-axial leaded
components should be directed radially from the centre of the component when the
termination area array on the printed board is patterned for such radial orientation.

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SIST EN 61191-3:2018
IEC 61191-3:2017 © IEC 2017 – 9 –
5.3.5.4 Partially clinched leads
Partially clinched leads shall be bent sufficiently to provide the necessary mechanical restraint
during the soldering process. Alternate bend directions may be used. Diagonally opposite
corner leads on dual-in-line packages (DIPs) may be partially clinched to retain parts during
soldering operations. DIP leads should be bent outwards away from the longitudinal axis of
the body.
5.3.5.5 Straight-through lead terminations
Component leads terminated straight through shall not extend in excess of 1,5 mm for level C,
or 2,5 mm for level B, and no danger of shorts for level C, beyond the conductor surface, and
as a minimum shall be visible in the completed solder connection. The lead protrusion for
unsupported holes shall be discernible in the solder joint for levels A and B, and sufficient to
clinch for level C. The maximum protrusion in all levels shall not create the risk of shorts.
Assembly designs that necessitate different lead extensions are considered to have unique
mounting requirements to be noted on the approved assembly drawing.
5.3.5.6 Meniscus spacing and trimming
Components shall be mounted to provide a visible clearance between the coating meniscus
on each lead and the solder connection. Trimming of the component coating meniscus is
prohibited.
5.3.5.7 Lead trimming
Leads may be trimmed after soldering, provided the cutters do not damage the component or
solder connection due to physical shock. When lead cutting is performed after soldering, the
solder terminations shall either be reflowed or visually inspected at 10 times magnification to
ensure that the original solder connection has not been damaged (e.g. fractured) or deformed.
If the solder connection is reflowed, this shall be considered a part of the soldering process
and shall not be considered rework. This requirement is not intended to apply to components
that are designed so that a portion of the lead is intended to be removed after soldering (e.g.
breakaway tie bars).
NOTE This inspection at 10 times magnification is to evaluate the soldered termination for evidence of physical
damage or deformation, indicated by fractures that are smaller than the land sizes inspected in accordance with
1
IEC 61191-1, provided that the breakpoint does not expose lead material that is corrodible (e.g. Kovar™ [Fe 54/Ni
29/Co 17])
5.3.5.8 Hole obstruction
Components shall be mounted so that they do not obstruct solder flow onto the upper side
lands of plated through-holes required to be soldered (see Figure 2).
___________
1
 Kovar is an example of a suitable product available commercially. This information is given for the convenience
of users of this document and does not constitute an endorsement by IEC of this product.

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Component

Hard mount
Air

Not acceptable


Solder

IEC

Figure 2 – Hole obstruction
5.3.5.9 Metal-cased component insulation
Metal-cased components shall be insulated from adjacent electrically conductive elements.
Insulation material shall be compatible with the circuit and printed board material.
5.3.5.10 Jumper wires
Jumper wires shall conform to the applicable design specification(s) and shall be documented
on the assembly drawing.
6 Acceptance requirements
6.1 General
Materials, processes and procedures described and specified in IEC 61191-1 provide for
soldered interconnections that are better than the minimum acceptance requirements in this
clause. Processes and their controls should be capable of producing products meeting or
exceeding the acceptance criteria for a level C product.
6.2 Control and corrective actions
6.2.1 General
The detailed requirements for acceptance, corrective action limits, control limit determination
and general assembly criteria described in IEC 61191-1 are a mandatory part of this standard.
In addition, the criteria defined in Subclauses 6.2.2 to 6.3.3 shall meet the requirements for all
through-hole assembly and connection acceptability.
6.2.2 Interfacial connections (vias)
Unsupported holes with leads, o
...