IEC 60115-4:2022

Fixed resistors for use in electronic equipment - Part 4: Sectional specification: Power resistors for through hole assembly on circuit boards (THT) or for assembly on chassis

IEC 60115-4:2022 relates to resistors having a rated dissipation typically greater than 1 W up to and including 1 000 W for use in electronic equipment. This document is applicable to fixed power resistors with a maximum surface temperature (MET) higher than the preferred upper category temperature (UCT) of 200 °C.
NOTE Heat sink resistors, i.e. resistors which in their operation depend on being mounted on a dedicated heat sink, owing to their special temperature conditions, are covered by a special sectional specification (under consideration at the time of publication).
These resistors are typically described according to types (different geometric shapes) and styles (different dimensions), and product technology.
The object of this document is to define preferred ratings and characteristics and to select from IEC 60115-1 the appropriate quality assessment procedures, tests and measuring methods and to give general performance requirements for this type of resistor.
NOTE SMD resistors are covered by IEC 60115-8, regardless of their dissipation.
This edition includes the following significant technical changes with respect to the previous edition:
the definitions of product technologies and product classification levels of the generic specification, IEC 60115-1:2020, have been adopted;
a basis for the optional specification of the lead eccentricity of axial leaded resistors has been amended in 4.2;
the 'period-pulse high-voltage overload test' of IEC 60115-1:2020, 8.3 has been adopted as default test method in 5.3.9, thereby replacing the legacy test 'periodic-pulse overload test of IEC 60115-1:2020, 8.4;
the revised solderability test of IEC 60115-1:2020, 11.1 has been adopted in 5.3.22 and 5.3.23;
the combined solvent resistance test of IEC 60115-1:2020, 11.3 has been adopted in 5.3.25;
the 'endurance at room temperature test' of IEC 60115-1:2020, 7.2 has been reworked and adopted in 5.3.5;
the 'single-pulse high-voltage overload test' of IEC 60115-1:2020, 8.2, applied with the pulse shape 10/700 in 5.3.8, is complemented with the optional alternative provided by the pulse shape 1,2/50 in 5.4.1.
climatic tests for 'operation at low temperature' of IEC 60115 1:2020, 10.2, and for 'damp heat, steady state, accelerated' of IEC 60115‑1:2020, 10.5, have been adopted as optional tests in 5.4.5. and 5.4.6, respectively;
inclusion of an optional flammability test as 5.4.8;
new guidance is provided in 6.2 on the presentation of stability requirements with their permissible absolute and relative deviations;
acceptance criteria for the visual inspection have been added in 6.5 and in Annex B;
visual inspection for the primary and proximity packaging has been added in 6.5.3 and in 7.2;
the periodical evaluation of termination platings has been added as a new topic of quality assessment in 9.8;
the revised test clause numbering of IEC 60115-1:2020 has been applied;
a new Annex C has been added to summarize workmanship requirements for the assembly of leaded power resistors, e.g. as given in the prior IEC 61192 series of standards;
the informative Annex F on radial formed styles has been amended with details on a formed Z-bend style for surface-mount assembly;
furthermore, the informative Annex X has been ad

Résistances fixes utilisées dans les équipements électroniques - Partie 4: Spécification intermédiaire: Résistances de puissance pour assemblage par trous traversants sur cartes de circuit imprimé (carte THT) ou pour assemblage sur châssis

L’IEC 60115-4:2022 couvre les résistances ayant un pouvoir de dissipation assignée généralement supérieur à 1 W et pouvant atteindre 1 000 W, qui sont utilisées dans les équipements électroniques. Le présent document s’applique aux résistances de puissance fixes, dont la température de surface maximale (qui correspond à la MET) est supérieure à la température maximale de catégorie (UCT) préférentielle de 200 °C.
NOTE Les résistances à radiateur, c’est-à-dire les résistances dont le fonctionnement impose qu’elles soient montées sur un radiateur réservé, en raison de leurs conditions de température particulières, sont couvertes par une spécification intermédiaire qui leur est réservée (à l’étude à la date de publication du présent document).
Ces résistances sont généralement décrites selon des types (différentes formes géométriques), des modèles (différentes dimensions) et des technologies de produit.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l’édition précédente:
a) adoption des définitions des technologies de produit et des niveaux de classification des produits de la spécification générique, IEC 60115-1:2020;
b) amendement en 4.2 d’une base pour la spécification facultative de l’excentricité des broches, pour les résistances à broches axiales;
c) intégration en 5.3.9, en tant que méthode d’essai par défaut, de l’"essai de surcharge haute tension à impulsions périodiques" donné dans l’IEC 60115‑1:2020, 8.3, entraînant le d) remplacement de l’ancien "essai de surcharge à impulsions périodiques" donné dans l’IEC 60115-1:2020, 8.4;
d) intégration en 5.3.22 et 5.3.23 de la révision de l’essai de brasabilité de l’IEC 60115-1:2020, 11.1;
e) intégration en 5.3.25 de l’essai de résistance au solvant combiné de l’IEC 60115-1:2020, 11.3;
f) refonte et intégration en 5.3.5 de l’essai d’endurance à température ambiante de l’IEC 60115-1:2020, 7.2;
g) ajout de la forme d’ondes des impulsions 1,2/50, spécifiée en 5.4.1, comme variante facultative en 5.3.8 à l’"essai de surcharge haute tension à une seule impulsion" donné dans l’IEC 60115-1:2020, 8.2, appliqué avec la forme d’ondes des impulsions 10/700;
h) intégration en tant qu’essais facultatifs des essais climatiques relatifs au "fonctionnement à basse température" de l’IEC 60115-1:2020, 10.2, et à "chaleur humide, essai continu, accéléré" de l’IEC 60115-1:2020, 10.5, respectivement en 5.4.5 et 5.4.6;
i) ajout d’un essai facultatif d’inflammabilité en 5.4.8;
j) ajout de nouvelles recommandations en 6.2 sur la présentation des exigences de stabilité, ainsi que leurs écarts absolus et relatifs admis;
k) ajout de critères d’acceptation pour l’examen visuel en 6.5 et à l’Annexe B;
l) ajout d’un examen visuel pour l’emballage principal et l’emballage de proximité en 6.5.3 et en 7.2;
m) ajout de l’évaluation périodique des revêtements des sorties comme nouveau sujet de l’évaluation de la qualité en 9.8;
n) application de la numérotation corrigée des articles sur les essais de l’IEC 60115-1:2020;
o) ajout d’une nouvelle Annexe C pour synthétiser les exigences relatives à la qualité d’exécution pour l’assemblage de résistance de puissance à broches, par exemple celles données dans l’ancienne série de normes IEC 61192;
p) amendement de l’Annexe F informative sur les modèles à broches orientées radialement, en y intégrant des informations sur un modèle à courbure en Z, pour montage en surface;
q) ajout de l’Annexe X informative pour présenter les références croisées des éléments qui composent l’édition précédente du présent document.

General Information

• Status: Published
• Publication Date: 28-Nov-2022
• ICS: 31.040.10 - Fixed resistors
• Technical Committee: TC 40 - Capacitors and resistors for electronic equipment
• Drafting Committee: MT 60115-4 - TC 40/MT 60115-4
• Current Stage: PPUB - Publication issued
• Start Date: 27-Dec-2022
• Completion Date: 29-Nov-2022

Standards Content (Sample)

IEC 60115-4 ®
Edition 3.0 2022-11
INTERNATIONAL
STANDARD
colour
inside
Fixed resistors for use in electronic equipment –
Part 4: Sectional specification: Power resistors for through hole assembly on
circuit boards (THT) or for assembly on chassis
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IEC 60115-4 ®
Edition 3.0 2022-11
INTERNATIONAL
STANDARD
colour
inside
Fixed resistors for use in electronic equipment –

Part 4: Sectional specification: Power resistors for through hole assembly on

circuit boards (THT) or for assembly on chassis

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.040.10 ISBN 978-2-8322-6088-3

– 2 – IEC 60115-4:2022 © IEC 2022
CONTENTS
FOREWORD . 8
1 Scope . 11
2 Normative references . 11
3 Terms, definitions, product types, product technologies and product classification. 12
3.1 Terms and definitions . 12
3.2 Product types . 13
3.2.1 General . 13
3.2.2 Axial type . 13
3.2.3 Radial type . 13
3.2.4 Vertical type . 14
3.2.5 Tubular types . 14
3.2.6 Metal housed wire-wound resistors . 15
3.2.7 Any other type . 15
3.3 Resistor encapsulation and material of termination . 15
3.3.1 Conformal lacquer coat . 15
3.3.2 Silicone cement coating . 15
3.3.3 Enamel coating . 16
3.3.4 Ceramic housed resistor . 16
3.3.5 Wire termination . 16
3.4 Product technologies . 16
3.4.1 General . 16
3.4.2 Metal film technology . 17
3.4.3 Metal glaze technology . 17
3.4.4 Metal oxide technology . 17
3.4.5 Wire-wound technology . 17
3.4.6 Metal strip technology . 17
3.4.7 Any other technology . 18
3.5 Product classification . 18
4 Preferred characteristics . 18
4.1 General . 18
4.2 Preferred types, styles and dimensions . 18
4.2.1 Axial type . 18
4.2.2 Ceramic housed type with axial lead wires . 22
4.2.3 Ceramic housed type with radial lead wires . 23
4.2.4 Radial or vertical ceramic housed type and dimensions . 25
4.2.5 Tubular type of power resistors . 26
4.2.6 Other types . 27
4.3 Preferred climatic categories . 27
4.4 Resistance . 28
4.5 Tolerances on resistance . 28
4.6 Rated dissipation P . 28
r
4.7 Limiting element voltage U . 30
max
4.8 Insulation voltage U . 30
ins
4.9 Insulation resistance R . 30
ins
5 Tests and test severities . 30
5.1 General provisions for tests invoked by this specification . 30

5.2 Preparation of specimen . 31
5.2.1 Drying . 31
5.2.2 Mounting of power resistors on test boards . 31
5.2.3 Mounting of power resistors on test racks . 32
5.2.4 Specification of test boards/ racks for any other type of high-power

resistors . 34
5.3 Details of applicable tests . 34
5.3.1 Resistance . 34
5.3.2 Temperature coefficient of resistance . 34
5.3.3 Temperature rise . 35
5.3.4 Endurance at the rated temperature 70 °C . 35
5.3.5 Endurance at room temperature . 36
5.3.6 Endurance at a maximum temperature: UCT with category dissipation . 37
5.3.7 Short-term overload . 37
5.3.8 Single-pulse high-voltage overload test . 38
5.3.9 Periodic-pulse high-voltage overload test . 38
5.3.10 Visual examination . 40
5.3.11 Gauging of dimensions . 40
5.3.12 Detail dimensions . 41
5.3.13 Robustness of the resistor body . 41
5.3.14 Robustness of terminations . 41
5.3.15 Bump . 42
5.3.16 Shock . 42
5.3.17 Vibration . 42
5.3.18 Rapid change of temperature . 43
5.3.19 Rapid change of temperature, ≥ 100 cycles . 43
5.3.20 Climatic sequence . 43
5.3.21 Damp heat, steady state . 44
5.3.22 Solderability, with lead-free solder . 45
5.3.23 Solderability, with SnPb solder . 46
5.3.24 Resistance to soldering heat . 46
5.3.25 Solvent resistance . 47
5.3.26 Insulation resistance . 47
5.3.27 Voltage proof . 47
5.4 Optional and/or additional tests . 48
5.4.1 Single-pulse high-voltage overload test . 48
5.4.2 Periodic-pulse overload test . 48
5.4.3 Electrostatic discharge (ESD) . 49
5.4.4 Robustness of threaded stud or screw terminations . 49
5.4.5 Operation at low temperature. 50
5.4.6 Damp heat, steady state, accelerated . 50
5.4.7 Accidental overload test. 51
5.4.8 Flammability . 51
6 Performance requirements. 52
6.1 General . 52
6.2 Limits for change of resistance at test . 52
6.3 Temperature coefficient of resistance . 54
6.4 Temperature rise . 54
6.5 Visual inspection . 55

– 4 – IEC 60115-4:2022 © IEC 2022
6.5.1 General visual criteria . 55
6.5.2 Visual criteria after tests .
...