|
IEC 62812
Edition 1.0 2019-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Low resistance measurements – Methods and guidance
Mesures de faibles résistances – Méthodes et recommandations
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.: +41 22 919 02 11
3, rue de
CH-1211 Geneva 20
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and withdrawn publications.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
.
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:
[email protected] .
IEC 62812
Edition 1.0 2019-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Low resistance measurements – Methods and guidance
Mesures de faibles résistances – Méthodes et recommandations
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.040.01 ISBN 978-2-8322-6870-4
– 2 – IEC 62812:2019 © IEC 2019
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Resistance measurement phenomena . 7
4.1 General . 7
4.2 Lead and contact resistance . 7
4.3 Self-heating . 9
4.4 Variation of resistance with temperature . 10
4.5 Thermoelectric e.m.f. . 12
4.6 Peltier effect . 15
5 Methods of measurement . 16
5.1 General . 16
5.2 Four-wire resistance measurement . 16
5.3 Offset compensation method . 19
5.4 Current inversion method . 22
5.5 Differential current inversion method . 25
5.6 Short-term trigger method . 28
6 Connecting the specimen . 32
6.1 Resistors with lead wires for soldered assembly . 32
6.1.1 Connecting leaded resistors in a test fixture . 32
6.2 Resistors with solder terminations for surface mount assembly . 33
6.2.1 Connecting SMD resistors on a test substrate. 33
6.2.2 Connecting SMD resistors in a test fixture . 35
7 Information to be given in the relevant component specification . 36
Annex A (normative) Letter symbols and abbreviated terms . 37
A.1 Letter symbols . 37
A.2 Abbreviated terms . 38
Annex B (informative) Test results of soldering pad with Kelvin connection for surface
mount resistors . 39
B.1 General . 39
B.2 Test procedures . 39
B.2.1 Test substrates . 39
B.2.2 Test method . 41
B.3 Measurement result and studies . 42
Bibliography . 45
Figure 1 – Resistance measurement using two-wire sensing . 8
Figure 2 – Variation of resistance with temperature (random example) . 10
Figure 3 – Resistances on a resistor with lead wires . 11
Figure 4 – SMD chip resistor on a PCB . 12
Figure 5 – Thermoelectric e.m.f. . 13
Figure 6 – Thermocouples on a resistor with lead wires . 14
Figure 7 – Resistance measurement affected by thermoelectric e.m.f. . 15
Figure 8 – Four-wire resistance measurement . 17
Figure 9 – Offset compensation method for resistance measurement . 19
Figure 10 – Current and voltage in the offset compensation method . 20
Figure 11 – Current inversion method for resistance measurement . 22
Figure 12 – Current and voltage in the current inversion method . 23
Figure 13 – Current and voltage in the differential current inversion method . 26
Figure 14 – Example of resistor specimen. 31
Figure 15 – Connecting leaded resistors in a test fixture . 32
Figure 16 – Resistance of cylindrical copper lead wires . 33
Figure 17 – Soldering pad of test substrate for Kelvin (four-point) connections . 34
Figure 18 – Resistance of PCB conductor tracks with 35 µm copper thickness. 35
Figure 19 – Example for connecting SMD resistors on a test fixture . 36
Figure B.1 – Lengths of soldering pad . 40
Figure B.2 – Position of voltage sense conductor . 40
Figure B.3 – Thickness of the solder printing screen and position of sense line . 43
Figure B.4 – Position of voltage-sensing line. 43
Figure B.5 – Soldering pad length . 44
Figure B.6 – Recommended soldering pad . 44
Table 1 – Relative Seebeck coefficients of selected metals. 13
Table A.1 – Letter symbols . 37
Table B.1 – Thickness of solder printing screen . 41
Table B.2 – Table of test conditions . 42
– 4 – IEC 62812:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW RESISTANCE MEASUREMENTS –
METHODS AND GUIDANCE
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 con
...