IEC 61191-2:2017

Printed board assemblies - Part 2: Sectional specification - Requirements for surface mount soldered assemblies

IEC 61191-2:2017 gives the requirements for surface mount solder connections. The requirements pertain to those assemblies that are totally surface mounted or to the surface mounted portions of those assemblies that include other related technologies (e.g. through-hole, chip mounting, terminal mounting, etc.).
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;
b) some of the terminology used in the document has been updated;
c) references to IEC standards have been corrected;
d) five termination styles have been added.
The contents of the corrigendum of September 2019 have been included in this copy.

Ensembles de cartes imprimées - Partie 2: Spécification intermédiaire - Exigences relatives à l'assemblage par brasage pour montage en surface

L’IEC 61191-2:2017 spécifie les exigences relatives aux connexions brasées pour montage en surface. Les exigences se rapportent aux ensembles intégrant uniquement le montage en surface ou aux portions d’ensembles pour montage en surface incluant d’autres technologies associées (par exemple montage par trous traversants, montage à puce, à borne, etc.).
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) mise à jour des exigences pour qu’elles soient conformes aux critères d’acceptation de l’IPC‑A-610F;
b) mise à jour d’une partie de la terminologie utilisée dans le présent document;
c) correction des références aux normes IEC;
d) ajout de cinq styles de terminaisons.

General Information

• Status: Published
• Publication Date: 22-May-2017
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 31.190 - Electronic component assemblies
• ICS: 31.240 - Mechanical structures for electronic equipment
• Technical Committee: TC 91 - Electronics assembly technology
• Drafting Committee: WG 2 - TC 91/WG 2
• Current Stage: PPUB - Publication issued
• Start Date: 30-May-2017
• Completion Date: 23-May-2017

Relations

• Corrected By: IEC 61191-2:2017/COR1:2019 - Corrigendum 1 - Printed board assemblies - Part 2: Sectional specification - Requirements for surface mount soldered assemblies
• Effective Date: 05-Sep-2023
• Revises: IEC 61191-2:2013 - Printed board assemblies - Part 2: Sectional specification - Requirements for surface mount soldered assemblies
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61191-2 ®
Edition 3.0 2017-05
INTERNATIONAL
STANDARD
colour
inside
Printed board assemblies –
Part 2: Sectional specification – Requirements for surface mount soldered
assemblies
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: [phone]
3, rue de Varembé Fax: [phone]
CH-1211 Geneva 20 [e-mail]
Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 20 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 65 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: [e-mail].
IEC 61191-2 ®
Edition 3.0 2017-05
INTERNATIONAL
STANDARD
colour
inside
Printed board assemblies –
Part 2: Sectional specification – Requirements for surface mount soldered

assemblies
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.190; 31.240 ISBN 978-2-8322-4322-0

– 2 – IEC 61191-2:2017 © IEC 2017
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 General requirements . 7
5 Surface mounting of components . 7
5.1 General . 7
5.2 Alignment requirements . 8
5.3 Process control . 8
5.4 Surface mounted component requirements . 8
5.5 Flatpack lead forming . 8
5.5.1 General . 8
5.5.2 Surface mounted device lead bends . 8
5.5.3 Surface mounted device lead deformation . 9
5.5.4 Flattened leads . 9
5.5.5 Dual-in-line packages (DIPs) . 9
5.5.6 Parts not configured for surface mounting . 9
5.6 Small devices with two terminations . 9
5.6.1 General . 9
5.6.2 Stack mounting . 9
5.6.3 Devices with external deposited elements . 9
5.7 Lead component body positioning . 10
5.7.1 General . 10
5.7.2 Axial-leaded components . 10
5.7.3 Other components . 10
5.8 Parts configured for butt lead mounting . 10
5.9 Non-conductive adhesive coverage limits . 10
6 Acceptance requirements . 10
6.1 General . 10
6.2 Control and corrective actions . 10
6.3 Surface soldering of leads and terminations . 11
6.3.1 General . 11
6.3.2 Solder fillet height and heel fillets . 11
6.3.3 Flat ribbon L and gull-wing leads . 12
6.3.4 Round or flattened (coined) leads . 13
6.3.5 J leads . 14
6.3.6 Rectangular or square end component . 15
6.3.7 Cylindrical end-cap terminations . 16
6.3.8 Bottom only terminations . 17
6.3.9 Castellated terminations . 18
6.3.10 Butt joints . 19
6.3.11 Inward L-shaped ribbon leads . 20
6.3.12 Flat lug leads . 21
6.3.13 Ball grid array . 22
6.3.14 Column grid array . 23
6.3.15 Bottom termination components . 24

6.3.16 Components with bottom thermal plane terminations (D-Pak) . 24
6.3.17 P-style terminations . 26
6.4 General post-soldering requirements applicable to all surface-mounted
assemblies . 26
6.4.1 Dewetting . 26
6.4.2 Leaching . 26
6.4.3 Pits, voids, blowholes, and cavities . 26
6.4.4 Solder wicking . 27
6.4.5 Solder webs and skins . 27
6.4.6 Bridging . 27
6.4.7 Degradation of marking . 27
6.4.8 Solder spikes . 27
6.4.9 Disturbed joint . 27
6.4.10 Component damage. 27
6.4.11 Open circuit, non-wetting . 27
6.4.12 Component tilting. 27
6.4.13 Non-conducting adhesive encroachment . 28
6.4.14 Open circuit, no solder available . 28
6.4.15 Component on edge . 28
7 Rework and repair . 28
Annex A (normative) Placement requirements for surface mounted devices . 30
A.1 General . 30
A.2 Component positioning . 30
A.3 Small devices incorporating two terminations . 30
A.3.1 Metallization coverage over the land (side-to-side) . 30
A.3.2 Metallization coverage over the land (end) . 30
A.4 Mounting of cylindrical end-cap devices (MELFs) . 30
A.5 Registration of castellated chip carriers . 30
A.6 Surface mounted device lead and land contact . 30
A.7 Surface mounted device lead side overhang . 30
A.8 Surface mounted device lead toe overhang . 31
A.9 Surface mounted device lead height off land (prior to soldering) . 31
A.10 Positioning of J lead devices . 31
A.11 Positioning gull-wing lead devices . 31
A.12 External connections to packaging and interconnect structures . 31
Bibliography . 32

Figure 1 – Lead formation for surface mounted device . 8
Figure 2 – Fillet height . 12
Figure 3 – Flat ribbon and gull-wing leads . 13
Figure 4 – Round or flattened (coined) lead joint . 14
Figure 5 – J lead joint . 15
Figure 6 – Rectangular or square end components . 16
Figure 7 – Cylindrical end-cap terminations . 17
Figure 8 – Bottom only terminations . 18
Figure 9 – Leadless chip carriers with castellated terminations . 19
Figure 10 – Butt joints . 20

– 4 – IEC 61191-2:2017 © IEC 2017
Figure 11 – Inward L-shaped ribbon leads . 21
Figure 12 – Flat lug leads .
...

IEC 61191-2 ®
Edition 3.0 2017-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Printed board assemblies –
Part 2: Sectional specification – Requirements for surface mount soldered
assemblies
Ensembles de cartes imprimées –
Partie 2: Spécification intermédiaire – Exigences relatives à l’assemblage par
brasage pour montage en surface

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org
The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English
committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary
details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and
once a month by email. French extracted from the Terms and Definitions clause of
IEC publications issued since 2002. Some entries have been
IEC Customer Service Centre - webstore.iec.ch/csc collected from earlier publications of IEC TC 37, 77, 86 and
If you wish to give us your feedback on this publication or CISPR.

need further assistance, please contact the Customer Service

Centre: [e-mail].
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Recherche de publications IEC - Electropedia - www.electropedia.org
webstore.iec.ch/advsearchform Le premier dictionnaire d'électrotechnologie en ligne au
La recherche avancée permet de trouver des publications IEC monde, avec plus de 22 000 articles terminologiques en
en utilisant différents critères (numéro de référence, texte, anglais et en français, ainsi que les termes équivalents dans
comité d’études,…). Elle donne aussi des informations sur les 16 langues additionnelles. Egalement appelé Vocabulaire
projets et les publications remplacées ou retirées. Electrotechnique International (IEV) en ligne.

IEC Just Published - webstore.iec.ch/justpublished Glossaire IEC - std.iec.ch/glossary
Restez informé sur les nouvelles publications IEC. Just 67 000 entrées terminologiques électrotechniques, en anglais
Published détaille les nouvelles publications parues. et en français, extraites des articles Termes et Définitions des
Disponible en ligne et une fois par mois par email. publications IEC parues depuis 2002. Plus certaines entrées
antérieures extraites des publications des CE 37, 77, 86 et
Service Clients - webstore.iec.ch/csc CISPR de l'IEC.

Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
[e-mail].
IEC 61191-2 ®
Edition 3.0 2017-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Printed board assemblies –
Part 2: Sectional specification – Requirements for surface mount soldered

assemblies
Ensembles de cartes imprimées –

Partie 2: Spécification intermédiaire – Exigences relatives à l’assemblage par

brasage pour montage en surface

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.190; 31.240 ISBN 978-2-8322-7400-2

– 2 – IEC 61191-2:2017 © IEC 2017
CONTENTS
CONTENTS . 2
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 General requirements . 7
5 Surface mounting of components . 7
5.1 General . 7
5.2 Alignment requirements . 8
5.3 Process control . 8
5.4 Surface mounted component requirements . 8
5.5 Flatpack lead forming . 8
5.5.1 General . 8
5.5.2 Surface mounted device lead bends . 8
5.5.3 Surface mounted device lead deformation . 9
5.5.4 Flattened leads . 9
5.5.5 Dual-in-line packages (DIPs) . 9
5.5.6 Parts not configured for surface mounting . 9
5.6 Small devices with two terminations . 9
5.6.1 General . 9
5.6.2 Stack mounting . 9
5.6.3 Devices with external deposited elements . 9
5.7 Lead component body positioning . 10
5.7.1 General . 10
5.7.2 Axial-leaded components . 10
5.7.3 Other components . 10
5.8 Parts configured for butt lead mounting . 10
5.9 Non-conductive adhesive coverage limits . 10
6 Acceptance requirements . 10
6.1 General . 10
6.2 Control and corrective actions . 10
6.3 Surface soldering of leads and terminations . 11
6.3.1 General . 11
6.3.2 Solder fillet height and heel fillets . 11
6.3.3 Flat ribbon L and gull-wing leads . 12
6.3.4 Round or flattened (coined) leads . 13
6.3.5 J leads . 14
6.3.6 Rectangular or square end component . 15
6.3.7 Cylindrical end-cap terminations . 16
6.3.8 Bottom only terminations . 17
6.3.9 Castellated terminations . 18
6.3.10 Butt joints . 19
6.3.11 Inward L-shaped ribbon leads . 20
6.3.12 Flat lug leads . 21
6.3.13 Ball grid array . 22
6.3.14 Column grid array . 23

6.3.15 Bottom termination components . 24
6.3.16 Components with bottom thermal plane terminations (D-Pak) . 24
6.3.17 P-style terminations . 26
6.4 General post-soldering requirements applicable to all surface-mounted
assemblies . 26
6.4.1 Dewetting . 26
6.4.2 Leaching . 26
6.4.3 Pits, voids, blowholes, and cavities . 26
6.4.4 Solder wicking . 27
6.4.5 Solder webs and skins . 27
6.4.6 Bridging . 27
6.4.7 Degradation of marking . 27
6.4.8 Solder spikes . 27
6.4.9 Disturbed joint . 27
6.4.10 Component damage. 27
6.4.11 Open circuit, non-wetting . 27
6.4.12 Component tilting. 27
6.4.13 Non-conducting adhesive encroachment . 28
6.4.14 Open circuit, no solder available . 28
6.4.15 Component on edge . 28
7 Rework and repair . 28
Annex A (normative) Placement requirements for surface mounted devices . 30
A.1 General . 30
A.2 Component positioning . 30
A.3 Small devices incorporating two terminations . 30
A.3.1 Metallization coverage over the land (side-to-side) . 30
A.3.2 Metallization coverage over the land (e
...