IEC 61191-3:2017

IEC 61191-3 ®
Edition 2.0 2017-05
INTERNATIONAL
STANDARD
Printed board assemblies –
Part 3: Sectional specification – Requirements for through-hole mount soldered
assemblies
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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

– 2 – IEC 61191-3:2017 © IEC 2017

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

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

– 4 – IEC 61191-3:2017 © IEC 2017
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PRINTED BOARD ASSEMBLIES –
Part 3: Sectional specification – Requirements
for through-hole mount soldered assemblies

FOREWORD
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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
...