SIST EN 60068-2-20:2009
Environmental testing -- Part 2-20: Tests - Test T: Test methods for solderability and resistance to soldering heat of devices with leads
Environmental testing -- Part 2-20: Tests - Test T: Test methods for solderability and resistance to soldering heat of devices with leads
This part of IEC 60068 outlines Test T, applicable to devices with leads. Soldering tests for surface mounting devices (SMD) are described in IEC 60068-2-58. This standard provides procedures for determining the solderability and resistance to soldering heat of devices in applications using solder alloys, which are eutectic or near eutectic tin lead (Pb), or lead-free alloys. The procedures in this standard include the solder bath method and soldering iron method. The objective of this standard is to ensure that component lead or termination solderability meets the applicable solder joint requirements of IEC 61191-3 and IEC 61191-4. In addition, test methods are provided to ensure that the component body can resist against the heat load to which it is exposed during soldering.
Umgebungseinflüsse -- Teil 2-20: Prüfungen - Prüfung T: Prüfverfahren für die Lötbarkeit und Lötwärmebeständigkeit von Bauelementen mit herausgeführten Anschlüssen
Essais d'environnement -- Partie 2-20: Essais - Essai T: Méthodes d'essai pour la brasabilité et la résistance à la chaleur de brasage des dispositifs plombés
La CEI 60068-2-20:2008 décrit l'essai T qui s'applique aux dispositifs à broches. Les essais de brasage des composants pour montage en surface (CMS) sont décrits dans la CEI 60068-2-58. La présente norme fournit des procédures pour déterminer la brasabilité et la résistance à la chaleur de brasage des dispositifs dans les applications utilisant des alliages de brasure, qui sont soit des brasures étain plomb (Pb) eutectique ou quasi eutectique, soit des alliages de brasure sans plomb. Les procédures de la présente norme incluent les méthodes dites de bain de brasage et de fer à braser. Le but de la présente norme est de s'assurer que les broches des composants ou la brasabilité de leurs extrémités est en mesure de satisfaire aux exigences applicables aux joints de brasures des CEI 61191-3 et 61191-4. De plus, des méthodes d'essai sont fournies pour s'assurer que le corps du composant peut résister à la charge calorifique à laquelle il est exposé pendant le brasage. Les principales modifications techniques par rapport à la quatrième édition sont les suivantes:
- l'essai de gouttelette de brasure est supprimé;
- des conditions et des exigences d'essai concernant les brasures sans plomb sont ajoutées.
Okoljski preskusi - 2-20. del: Preskusi - Preskus T: Preskusne metode za določanje spajkljivosti in odpornosti proti toploti spajkanja za komponente z izvodi (IEC 60068-2-20:2008)
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Umgebungseinflüsse -- Teil 2-20: Prüfungen - Prüfung T: Prüfverfahren für die Lötbarkeit und Lötwärmebeständigkeit von Bauelementen mit herausgeführten AnschlüssenEssais d'environnement -- Partie 2-20: Essais - Essai T: Méthodes d'essai pour la brasabilité et la résistance à la chaleur de brasage des dispositifs plombésEnvironmental testing -- Part 2-20: Tests - Test T: Test methods for solderability and resistance to soldering heat of devices with leads19.040Preskušanje v zvezi z okoljemEnvironmental testingICS:Ta slovenski standard je istoveten z:EN 60068-2-20:2008SIST EN 60068-2-20:2009en,de01-januar-2009SIST EN 60068-2-20:2009SLOVENSKI
STANDARDSIST HD 323.2.20 S3:20031DGRPHãþD
SIST EN 60068-2-20:2009
EUROPEAN STANDARD EN 60068-2-20 NORME EUROPÉENNE
EUROPÄISCHE NORM September 2008
CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2008 CENELEC -
All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60068-2-20:2008 E
ICS 19.040 Supersedes HD 323.2.20 S3:1988
English version
Environmental testing -
Part 2-20: Tests -
Test T: Test methods for solderability and resistance
to soldering heat of devices with leads (IEC 60068-2-20:2008)
Essais d'environnement -
Partie 2-20: Essais -
Essai T: Méthodes d'essai
pour la brasabilité et la résistance
à la chaleur de brasage
des dispositifs plombés (CEI 60068-2-20:2008)
Umgebungseinflüsse -
Teil 2-20: Prüfungen -
Prüfung T: Prüfverfahren für die Lötbarkeit und Lötwärmebeständigkeit
von Bauelementen mit herausgeführten Anschlüssen (IEC 60068-2-20:2008)
This European Standard was approved by CENELEC on 2008-08-01. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom.
SIST EN 60068-2-20:2009
EN 60068-2-20:2008 – 2 – Foreword The text of document 91/764/FDIS, future edition 5 of IEC 60068-2-20, prepared by IEC TC 91, Electronics assembly technology, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60068-2-20 on 2008-08-01. This European Standard supersedes HD 323.2.20 S3:1988. The major technical changes with regard to HD 323.2.20 S3:1988 are the following: – the solder globule test is deleted; – test conditions and requirements for lead-free solders are added.
The following dates were fixed: – latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement
(dop) 2009-05-01 – latest date by which the national standards conflicting
with the EN have to be withdrawn
(dow) 2011-08-01 Annex ZA has been added by CENELEC. __________ Endorsement notice The text of the International Standard IEC 60068-2-20:2008 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 60068-2-54 NOTE
Harmonized as EN 60068-2-54:2006 (not modified). IEC 60068-2-58 NOTE
Harmonized as EN 60068-2-58:2004 (not modified). IEC 60068-2-69 NOTE
Harmonized as EN 60068-2-69:2007 (not modified). IEC 61190-1-3 NOTE
Harmonized as EN 61190-1-3:2007 (not modified). __________ SIST EN 60068-2-20:2009
– 3 – EN 60068-2-20:2008
Annex ZA
(normative)
Normative references to international publications with their corresponding European publications
The following referenced documents are indispensable for the application 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.
NOTE
When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies.
Publication Year Title EN/HD Year
IEC 60068-1 - 1) Environmental testing -
Part 1: General and guidance EN 60068-1 1994 2)
IEC 60068-2-2 - 1) Environmental testing -
Part 2-2: Tests - Test B: Dry heat EN 60068-2-2 2007 2)
IEC 60068-2-66 - 1) Environmental testing -
Part 2-66: Test methods - Test Cx: Damp heat, steady state (unsaturated pressurized vapour) EN 60068-2-66 1994 2)
IEC 60068-2-78 - 1) Environmental testing -
Part 2-78: Tests - Test Cab: Damp heat, steady state EN 60068-2-78 2001 2)
IEC 60194 - 1) Printed board design, manufacture and assembly - Terms and definitions EN 60194 2006 2)
IEC 61191-3 - 1) Printed board assemblies -
Part 3: Sectional specification -
Requirements for through-hole mount soldered assemblies EN 61191-3 1998 2)
IEC 61191-4 - 1) Printed board assemblies -
Part 4: Sectional specification -
Requirements for terminal soldered assemblies EN 61191-4 1998 2)
1) Undated reference.
2) Valid edition at date of issue.
SIST EN 60068-2-20:2009
SIST EN 60068-2-20:2009
IEC 60068-2-20Edition 5.0 2008-07INTERNATIONAL STANDARD
Environmental testing –
Part 2-20: Tests – Test T: Test methods for solderability and resistance to soldering heat of devices with leads
INTERNATIONAL ELECTROTECHNICAL COMMISSION RICS 19.040 PRICE CODEISBN 2-8318-9919-2
® Registered trademark of the International Electrotechnical Commission SIST EN 60068-2-20:2009
– 2 – 60068-2-20 © IEC:2008(E) CONTENTS FOREWORD.4 1 Scope and object.6 2 Normative references.6 3 Terms and definitions.7 4 Test Ta: Solderability of wire and tag terminations.8 4.1 Object and general description of the test.8 4.1.1 Test methods.8 4.1.2 Specimen preparation.8 4.1.3 Initial measurements.9 4.1.4 Accelerated ageing.9 4.2 Method 1: Solder bath.9 4.2.1 Description of the solder bath.9 4.2.2 Flux.10 4.2.3 Procedure.10 4.2.4 Test conditions.10 4.2.5 Final measurements and requirements.11 4.3 Method 2: Soldering iron at 350 °C.11 4.3.1 Description of soldering irons.11 4.3.2 Solder and flux.12 4.3.3 Procedure.12 4.3.4 Final measurements and requirements.13 4.4 Information to be given in the relevant specification.13 5 Test Tb: Resistance to soldering heat.13 5.1 Object and general description of the test.13 5.1.1 Test methods.13 5.1.2 Initial measurements.14 5.2 Method 1: Solder bath.14 5.2.1 Description of the solder bath.14 5.2.2 Flux.14 5.2.3 Procedure.14 5.2.4 Test conditions.14 5.2.5 De-wetting.15 5.3 Method 2: Soldering iron.15 5.3.1 Description of soldering iron.15 5.3.2 Solder and flux.15 5.3.3 Procedure.15 5.4 Recovery.16 5.5 Final measurements and requirements.16 5.6 De-wetting (if applicable).16 5.7 Information to be given in the relevant specification.17 Annex A (informative) Example of apparatus for accelerated steam ageing process.18 Annex B (normative) Specification for flux constituents.19 Bibliography.20
Figure 1 – Diagram of contact angle.7 SIST EN 60068-2-20:2009
60068-2-20 © IEC:2008(E) – 3 – Figure 2 – Position of soldering iron.12 Figure A.1 – Example of apparatus.18
Table 1 – Solderability, Solder bath method: Test severities (duration and temperature).11 Table 2 – Resistance to soldering heat, Solder bath method: Test severities (duration and temperature).15
SIST EN 60068-2-20:2009
– 4 – 60068-2-20 © IEC:2008(E) INTERNATIONAL ELECTROTECHNICAL COMMISSION ____________
ENVIRONMENTAL TESTING –
Part 2-20: Tests –
Test T: Test methods for solderability and resistance to soldering heat of devices with leads
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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment declared to be in conformity with an IEC Publication. 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 60068-2-20 has been prepared by IEC technical committee 91: Electronics assembly technology. This fifth edition cancels and replaces the fourth edition, published in 1979 and its Amendment 2 (1987). Amendment 2 includes Amendment 1. This fifth edition constitutes a technical revision and includes test conditions and requirements for use of lead-free solder. The major technical changes with regard to the fourth edition are the following: – the solder globule test is deleted; – test conditions and requirements for lead-free solders are added. SIST EN 60068-2-20:2009
60068-2-20 © IEC:2008(E) – 5 – The text of this standard is based on the following documents: FDIS Report on voting 91/764/FDIS 91/774/RVD
Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. A list of all the parts in the IEC 60068 series, under the general title Environmental testing, can be found on the IEC website. The committee has decided that the contents of this publication will remain unchanged until the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to the specific publication. At this date, the publication will be • reconfirmed, • withdrawn, • replaced by a revised edition, or • amended. A bilingual version of this publication may be issued at a later date.
SIST EN 60068-2-20:2009
– 6 – 60068-2-20 © IEC:2008(E) ENVIRONMENTAL TESTING –
Part 2-20: Tests – Test T: Test methods for solderability and resistance to soldering heat of devices with leads
1 Scope and object This part of IEC 60068 outlines Test T, applicable to devices with leads. Soldering tests for surface mounting devices (SMD) are described in IEC 60068-2-58. This standard provides procedures for determining the solderability and resistance to soldering heat of devices in applications using solder alloys, which are eutectic or near eutectic tin lead (Pb), or lead-free alloys. The procedures in this standard include the solder bath method and soldering iron method. The objective of this standard is to ensure that component lead or termination solderability meets the applicable solder joint requirements of IEC 61191-3 and IEC 61191-4. In addition, test methods are provided to ensure that the component body can resist against the heat load to which it is exposed during soldering. NOTE Information about wetting time and wetting force can be obtained by test methods using a wetting balance. See IEC 60068-2-54 (solder bath method) and IEC 60068-2-69 (solder bath and solder globule method for SMDs). 2 Normative references The following referenced documents are indispensable for the application 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 60068-1, Environmental testing – Part 1: General and guidance IEC 60068-2-2, Environmental testing – Part 2-2: Tests – Tests B: Dry heat IEC 60068-2-66, Environmental testing – Part 2-66: Test methods: Test Cx: Damp heat, steady state (unsaturated pressurized vapour) IEC 60068-2-78, Environmental testing – Part 2-78: Tests – Test Cab: Damp heat, steady State IEC 60194, Printed board design, manufacture and assembly – Terms and definitions IEC 61191-3, Printed board assemblies – Part 3: Sectional specification – Requirements for through-hole mount soldered assemblies IEC 61191-4, Printed board assemblies – Part 4: Sectional specification – Requirements for terminal soldered assemblies SIST EN 60068-2-20:2009
60068-2-20 © IEC:2008(E) – 7 – 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1
colophony natural resin obtained as the residue after removal of turpentine from the oleo-resin of the pine tree, consisting mainly of abietic acid and related resin acids, the remainder being resin acid esters NOTE "Rosin" is a synonym for colophony, and is deprecated because of the common confusion with the generic term "resin". 3.2
contact angle in general the angle enclosed between two planes, tangent to a liquid surface and a solid/liquid interface at their intersection (see Figure 1). In particular the contact angle of liquid solder in contact with a solid metal surface
Contact angle Liquid Solid IEC
1234/08
Figure 1 – Diagram of contact angle 3.3
wetting formation of an adherent coating of solder on a surface. A small contact angle is indicative of wetting 3.4
non-wetting inability to form an adherent coating of solder on a surface. In this case the contact angle is greater than 90° 3.5
de-wetting retraction of molten solder on a solid area that it has initially wetted NOTE In some cases an extremely thin film of solder may remain. As the solder retracts the contact angle increases. 3.6
solderability ability of the termination or lead of device to be wetted by solder at the temperature of the termination or lead which is assumed to be the lowest temperature in the soldering process within solderable temperature of solder alloy SIST EN 60068-2-20:2009
– 8 – 60068-2-20 © IEC:2008(E) 3.7
soldering time time required for a defined surface area to be wetted under specific conditions 3.8
resistance to soldering heat ability of device to withstand the highest temperature of the termination or lead in soldering process, within applicable temperature range of solder alloy 3.9
lead-free solder alloy that does not contain more than 0,1 % lead (Pb) by weight as its constituent and is used for joining components to substrates or for coating surfaces [75.1904 of IEC 60194] 4 Test Ta: Solderability of wire and tag terminations 4.1 Object and general description of the test 4.1.1 Test methods Test Ta provides two different test methods to determine the solderability of the areas on wire and tag terminations that are required to be wetted by solder. – Method 1: Solder bath – Method 2: Soldering iron The test method to be used shall be indicated in the relevant specification. The solder bath method is the one which simulates most closely the soldering procedures of flow soldering and similar soldering processes. The soldering iron method may be used in cases where Method 1 is impracticable. If required by the relevant specification, the test conditioning may be preceded by accelerated ageing. The following are recommended conditions: Ageing 1a: 1 h steam ageing Ageing 1b: 4 h steam ageing Ageing 2: 10 days damp heat, steady state condition (40 ± 2) °C; (93 ± 3) % RH
(Test Cab) Ageing 3a: 4 h at 155 °C dry heat (Test Bb) Ageing 3b: 16 h at 155 °C dry heat (Test Bb). Ageing 4: 4 h unsaturated pres
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---------------------- Page: 1 ----------------------
91/640/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJET DE COMITÉ POUR VOTE (CDV)
Project number IEC 60068-2-20, Ed. 5
Numéro de projet
IEC/TC or SC:
Secretariat / Secrétariat
TC 91
CEI/CE ou SC:
Japan
Submitted for parallel voting in Date of circulation Closing date for voting (Voting
CENELEC Date de diffusion mandatory for P-members)
Date de clôture du vote (Vote
2006-10-27
obligatoire pour les membres (P))
Soumis au vote parallèle au
CENELEC 2007-03-30
Also of interest to the following committees Supersedes document
Intéresse également les comités suivants Remplace le document
IEC TC 40, 47, 47D, 93, 104 91/554/CD – 91/602A/CC
Functions concerned
Fonctions concernées
Safety EMC Environment Quality assurance
Sécurité
CEM Environnement Assurance qualité
CE DOCUMENT EST TOUJOURS À L'ÉTUDE ET SUSCEPTIBLE DE THIS DOCUMENT IS STILL UNDER STUDY AND SUBJECT TO CHANGE. IT
MODIFICATION. IL NE PEUT SERVIR DE RÉFÉRENCE. SHOULD NOT BE USED FOR REFERENCE PURPOSES.
LES RÉCIPIENDAIRES DU PRÉSENT DOCUMENT SONT INVITÉS À RECIPIENTS OF THIS DOCUMENT ARE INVITED TO SUBMIT, WITH THEIR
PRÉSENTER, AVEC LEURS OBSERVATIONS, LA NOTIFICATION DES COMMENTS, NOTIFICATION OF ANY RELEVANT PATENT RIGHTS OF
DROITS DE PROPRIÉTÉ DONT ILS AURAIENT ÉVENTUELLEMENT WHICH THEY ARE AWARE AND TO PROVIDE SUPPORTING
CONNAISSANCE ET À FOURNIR UNE DOCUMENTATION EXPLICATIVE. DOCUMENTATION.
Title :
Titre :
IEC 60068-2-20, Ed. 5: Environmental
testing – Part 2-20: Tests – Test T: Test
methods for solderability and resistance
to soldering heat of leaded devices
Note d'introduction Introductory note
La version française sera diffusée au stade This CDV was prepared based on 91/554/CD
FDIS and the discussion results of 91/602A/CC
ATTENTION ATTENTION
VOTE PARALLÈLE IEC – CENELEC
CEI – CENELEC PARALLEL VOTING
L’attention des Comités nationaux de la CEI, membres du The attention of IEC National Committees, members of
CENELEC, est attirée sur le fait que ce projet de comité CENELEC, is drawn to the fact that this Committee Draft for
pour vote (CDV) de Norme internationale est soumis au Vote (CDV) for an International Standard is submitted for
vote parallèle. parallel voting.
Un bulletin de vote séparé pour le vote CENELEC leur sera A separate form for CENELEC voting will be sent to them by
envoyé par le Secrétariat Central du CENELEC. the CENELEC Central Secretariat.
Copyright © 2006 International Electrotechnical Commission, IEC. All rights reserved. It is
permitted to download this electronic file, to make a copy and to print out the content for the sole
purpose of preparing National Committee positions. You may not copy or "mirror" the file or
printed version of the document, or any part of it, for any other purpose without permission in
writing from IEC.
FORM CDV (IEC) 2005-09-23
---------------------- Page: 2 ----------------------
2
60068-2-20, Ed. 5/CDV © IEC:200X 91/640/CDV
BASIC ENVIRONMENTAL TESTING PROCEDURES
Part 2: Tests – Test T: Test methods for solderability and resistance to
soldering heat of devices with leads
1 Scope and object
This part of IEC 60068 outlines test T, applicable to devices with leads. Soldering tests for
surface mounting devices (SMD) are described in IEC 60068-2-58.
This standard provides procedures for determining the solderability and resistance to
soldering heat of devices in applications using solder alloys, which are eutectic or near
eutectic tin lead (Pb), or lead-free alloys.
The procedures in this standard include the solder bath method and soldering iron method.
The objective of this standard is to ensure that component lead or termination solderability
meets the applicable solder joint requirements of IEC 61191-3. In addition, test methods are
provided to ensure that the component body can resist against the heat load to which it is
exposed during soldering.
Note: Information about wetting time and wetting force can be obtained by test methods using a wetting balance.
See IEC 60068-2-54 (Bath method) and IEC 60068-2-69 (Solder globule method).
2 Normative references
The following referenced documents are indispensable for the application 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 60068-1, Environmental testing – Part 1: General and guidance
IEC 60068-2-2, Test B: Dry Heat
IEC 60068-2-66, Test Cx: Damp heat, steady state (unsaturated pressurized vapour)
IEC 60068-2-78, Test Ca: Damp Heat, Steady State
IEC 60194, Printed board design, manufacture and assembly –terms and definitions
IEC 61190-1-3, Attachement materials; requirements for electrical grade solder alloys and
fluxed and non-fluxed solid solders
IEC 61191-3, Printed board assemblies – Part 3: Sectional specification – Requirements
for through-hole mount soldered assemblies
3 Terms and definitions
3.1 colophony
a natural resin obtained as the residue after removal of turpentine from the oleo-resin of the
pine tree, consisting mainly of abietic acid and related resin acids, the remainder being resin
acid esters.
NOTE "Rosin" is a synonym for colophony, and is deprecated because of the common confusion with the
generic term "resin".
---------------------- Page: 3 ----------------------
3
60068-2-20, Ed. 5/CDV © IEC:200X 91/640/CDV
3.2 contact angle
in general the angle enclosed between two planes, tangent to a liquid surface and a
solid/liquid interface at their intersection (see Figure 1). In particular the contact angle of
liquid solder in contact with a solid metal surface.
Figure 1
3.3 wetting
the formation of an adherent coating of solder on a surface. A small contact angle is indica-
tive of wetting.
3.4 non-wetting
the inability to form an adherent coating of solder on a surface. In this case the contact angle
is much greater than 90°.
3.5 de-wetting
the retraction of molten solder on a solid area that it has initially wetted. In some cases an
extremely thin film of solder may remain. As the solder retracts the contact angle increases.
3.6 solderability
ability of the termination or lead of device to be wetted by solder at the temperature of the
termination or lead which is assumed to be the lowest temperature in the soldering process
within solderable temperature of solder alloy.
3.7 soldering time
the time required for a defined surface area to be wetted under specific conditions.
3.8 resistance to soldering heat
ability of device to withstand the highest temperature of the termination or lead in soldering
process, within applicable temperature range of solder alloy.
3.9 lead-free solder
see definition in IEC 60194
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4
60068-2-20, Ed. 5/CDV © IEC:200X 91/640/CDV
4 Test Ta: Solderability of wire and tag terminations
4.1 Object and general description of the test
4.1.1 Test methods
Test Ta provides two different test methods to determine the solderability of the areas on wire
and tag terminations that are required to be wetted by solder.
Method 1: Solder bath
Method 2: Soldering iron
The test method to be used shall be indicated in the relevant specification. The solder bath
method is the one which simulates most closely the soldering procedures of flow soldering
and similar soldering proecesses; however, it is not practicable to express the results as a
number.
The soldering iron method may be used in cases where Method 1 is impracticable.
If required by the relevant specification, the test conditioning may be preceded by accelerated
ageing. The following are recommended conditions:
Ageing 1a: 1 h steam ageing
Ageing 1b: 4 h steam ageing
Ageing 2: 10 days damp heat, steady state condition (Test Ca)
Ageing 3a: 4 h at 155°C dry heat (Test Ba)
Ageing 3b: 16 h at 155 °C dry heat (Test Ba).
Ageing 4: 4h unsaturated pressurized vapour (Test Cx)
4.1.2 Specimen preparation
The surface to be tested shall be in the "as received" condition and shall not be subsequently
touched by the fingers or otherwise contaminated.
The specimen shall not be cleaned prior to the application of a solderability test. If required
by the relevant specification, the specimen may be degreased by immersion in a neutral
organic solvent at room temperature.
4.1.3 Initial measurements
The specimens shall be visually examined and, if required by the relevant specification, elec-
trically and mechanically checked.
4.1.4 Accelerated ageing
If accelerated ageing is required by the relevant specification, one of the following procedures
shall be adopted. At the end of the conditioning, the specimen shall be subjected to standard
atomspheric conditions for testing for not less than 2 h and not more than 24 h.
NOTE Terminations may be detached if the ageing temperature is higher than the component's maximum
operating or storage temperature, or if the component is likely to degrade considerably at 100 °C in steam and
thus affect the solderability in a manner which would not normally occur in natural ageing.
4.1.4.1 Ageing 1
The relevant specification shall indicate whether ageing 1a (1 h in steam) or ageing 1b (4 h in
steam) is to be used. For these procedures the specimen is suspended, preferably with the
termination vertical, with the area to be tested positioned 25 mm to 30 mm above the surface
of boiling distilled water which is contained in a borosilicate glass or stainless steel vessel of
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suitable size (e.g., a 2 liter beaker). The termination shall be not less than 10 mm from the
walls of the vessel.
The vessel shall be provided with a cover of like material consisting of one or more plates
which are capable of covering approximately seven-eighths of the opening. A suitable method
of suspending the specimens shall be devised; perforations or slots in the cover are permitted
for this purpose. The specimen holder shall be non-metallic.
The level of water shall be maintained by the addition of hot distilled water, added gradually
in small quantities, so that the water will continue to boil vigorously; alternatively a reflux con-
denser may be provided if desired. (See Figure A.1).
4.1.4.2 Ageing 2
Specimens are subjected to 10 days damp heat, steady state, according to IEC 60068-2-78,
Test Ca: Damp Heat, Steady State.
4.1.4.3 Ageing 3
Specimens are subjected to 4 h or 16 h dry heat at 155 °C according to IEC 60068-2-2
Test B: Dry Heat.
4.1.4.4 Ageing 4
Specimens are subjected to 4 h at 120 °C and 85 % according to IEC 60068-2-66, Test Cx:
Damp heat, steady state (unsaturated pressureized vapour).
4.2 Method 1: Solder bath
This method provides a procedure for assessing the solderability of wires, tags, and termina-
tions of irregular form.
4.2.1 Description of the solder bath
The solder bath shall be not less than 40 mm in depth and not less than 300 ml in volume.
The bath shall contain solder as specified in Table 1.
4.2.2 Flux
The flux to be used shall consist of 25 % by weight of colophony in 75 % by weight of 2-
propanol (isopropanol) or of ethyl alcohol, as specified in Annex B.
When non-activated flux is inappropriate, the above flux with the addition of diethylammonium
chloride (analytical reagent grade), up to an amount of 0,2 % chloride (expressed as free
chlorine based on the colophony content), may be used as required by the relevant
specification.
4.2.3 Procedure
The surface of the molten solder shall be wiped clean and bright with a piece of suitable
material immediately before each test.
The termination to be tested shall be immersed first in the flux described in 4.2.2 at laboratory
temperature, and excess flux shall be eliminated either by draining off for a suitable time, or
by using any other procedure likely to produce a similar result. In case of dispute, drainage
shall be carried out for 1 min ± 5 s.
Note: Excessive remaining flux may boil when getting into contact with the liquid solder. Gas bubbles may stick to
the terminations’s surface and prevent wetting of the termination in the respective area.
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The termination is then immersed immediately in the solder bath in the direction of its
longitudinal axis. The point of immersion of the termination shall be at a distance not' less
than 10 mm from the walls of the bath.
The speed of immersion shall be 25 ± 2.5 mm/s and the termination shall remain immersed
for the time selected from Table 1 with the body of the component at the distance above the
solder prescribed in the relevant specification. The specimen shall then be withdrawn at 25 ±
2.5 mm/s.
For components having a high thermal capacity an immersion time of (5.0 ± 0.5) s or
(10 ± 1) s may be selected from Table 1.
If required by the relevant specification, a screen of thermally insulating material of
(1.5 ± 0.5) mm thickness with clearance, holes appropriate to the size of the termination may
be placed between the body of the component and the molten solder.
Any flux residue shall be removed with 2-propanol (isopropanol) or ethyl alcohol.
4.2.4 Test conditions
The duration and temperature of immersion shall be selected from Table 1, unless otherwise
prescribed by the relevant specification.
Table 1 – Solderability, Bath method: Test severities (duration and temperature)
Severity
Alloy composition
(215 ± 3) °C (235 ± 3) °C (245 ± 3) °C (250± 3) °C
(3 ± 0,3) s (10 ± 1) s (2 ± 0,2) s (5 ± 0,5) s (3 ± 0,3) s (3 ± 0,3) s
SnPb X X X X
Sn96,5Ag3,0Cu0,5 X
Sn99,3Cu0,7 X
Alloy composition for test purposes only. The solder alloys consist of 3,0 wt % to 4,0 wt % Ag, 0,5 wt % to 1,0 wt %
Cu, and the remainder of Sn may be used instead of Sn96.5Ag3.0Cu0.5. The solder alloys consist of 0,45 wt % to
0,9 wt % Cu and the remainder of Sn may be used instead of Sn99.3Cu0.7.
NOTE 1 “X” denotes ‘applicable’.
NOTE 2 Refer to 3.1 of IEC 61190-1-3 to identify alloy composition.
NOTE 3 The ba
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