SIST EN 60749-21:2005

SLOVENSKI SIST EN 60749-21:2005

STANDARD
december 2005
Polprevodniški elementi – Mehanske in klimatske preskusne metode – 21.
del: Spajkljivost (IEC 60749-21:2004)
Semiconductor devices – Mechanical and climatic test methods – Part 21:
Solderability (IEC 60749-21:2004)
ICS 31.080.01 Referenčna številka
SIST EN 60749-21:2005(en)
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

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EUROPEAN STANDARD EN 60749-21
NORME EUROPÉENNE
EUROPÄISCHE NORM February 2005

ICS 31.080


English version


Semiconductor devices –
Mechanical and climatic test methods
Part 21: Solderability
(IEC 60749-21:2004)


Dispositifs à semiconducteurs – Halbleiterbauelemente –
Méthodes d'essais mécaniques et Mechanische und klimatische
climatiques Prüfverfahren
Partie 21: Brasabilité Teil 21: Lötbarkeit
(CEI 60749-21:2004) (IEC 60749-21:2004)





This European Standard was approved by CENELEC on 2004-12-07. 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, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden,
Switzerland and United Kingdom.

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


© 2005 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 60749-21:2005 E

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EN 60749-21:2005 - 2 -
Foreword
The text of document 47/1741/FDIS, future edition 1 of IEC 60749-21, prepared by IEC TC 47,
Semiconductor devices, was submitted to the IEC-CENELEC parallel vote and was approved by
CENELEC as EN 60749-21 on 2004-12-07.
This mechanical and climatic test method, as it relates to solderability, is a complete rewrite of the test
contained in Subclause 2.1, Chapter 2 of EN 60749:1999.
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) 2005-09-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2008-01-01
__________
Endorsement notice
The text of the International Standard IEC 60749-21:2004 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 NOTE  Harmonized in the EN 60068 series (not modified).
IEC 60749 NOTE  Harmonized in the EN 60749 series (not modified).
IEC 60749-15 NOTE  Harmonized as EN 60749-15:2003 (not modified).
IEC 60749-20 NOTE  Harmonized as EN 60749-20:2003 (not modified).
__________

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NORME CEI
INTERNATIONALE
IEC



60749-21
INTERNATIONAL


Première édition
STANDARD

First edition

2004-03


Dispositifs à semiconducteurs –
Méthodes d'essais mécaniques
et climatiques –
Partie 21:
Brasabilité

Semiconductor devices –
Mechanical and climatic test methods –
Part 21:
Solderability
 IEC 2005 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
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Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
CODE PRIX
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PRICE CODE
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International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue

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60749-21  IEC:2005 – 3 –
CONTENTS
FOREWORD.7

1 Scope.13
2 Test apparatus .13
2.1 Solder bath.13
2.2 Dipping device.13
2.3 Optical equipment .13
2.4 Steam ageing equipment.15
2.5 Lighting equipment .15
2.6 Materials .15
2.6.1 Flux .15
2.6.2 Solder .15
2.7 SMD reflow equipment .17
2.7.1 Stencil or screen .17
2.7.2 Rubber squeegee or metal spatula .17
2.7.3 Test substrate .17
2.7.4 Solder paste .19
2.7.5 Reflow equipment.19
2.7.6 Flux removal solvent.19
3 Procedure .21
3.1 Preconditioning .21
3.1.1 Preconditioning by steam ageing .21
3.1.2 Preconditioning by high temperature storage .23
3.2 Procedure for dip and look solderability testing .23
3.2.1 Solder dip conditions .23
3.2.2 Procedure.23
3.3 Procedure for simulated board mounting reflow solderability testing of SMDs.39
3.3.1 Test equipment set-up .39
3.3.2 Specimen preparation and surface condition .41
3.3.3 Visual inspection .43
4 Summary.43

Bibliography.45

Figure 1 – Areas to be inspected for gullwing packages.31
Figure 2 – Areas to be inspected for J-lead packages .33
Figure 3 – Areas to be inspected in rectangular components (SMD method) .35
Figure 4 – Areas to be inspected in SOIC and QFP packages (SMD method) .37
Figure 5 – Flat peak type reflow profile .41

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60749-21  IEC:2005 – 5 –

Table 1 – Steam ageing conditions .21
Table 2 – Altitude versus steam temperature .21
Table 3 – Solder dip test conditions .23
Table 4 – Maximum limits of solder bath contaminant .29

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60749-21  IEC:2005 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

SEMICONDUCTOR DEVICES –
MECHANICAL AND CLIMATIC TEST METHODS –

Part 21: Solderability


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 60749-21 has been prepared by IEC technical committee 47:
Semiconductor devices.
This standard cancels and replaces IEC/PAS 62173 published in 2000. This first edition
constitutes a technical revision.
This part of the IEC 60749 series completes the full revision of IEC 60749 (1996).
This bilingual version (2005-10) replaces the English version.

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60749-21  IEC:2005 – 9 –
The text of this standard is based on the following documents:
FDIS Report on voting
47/1741/FDIS 47/1749/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.
The French version of this standard has not been voted upon.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
IEC 60749 consists of the following parts, under the general title Semiconductor devices –
Mechanical and climatic test methods:
Part 1: General
Part 2: Low air pressure
Part 3: External visual inspection
Part 4: Damp heat, steady state, highly accelerated stress test (HAST)
Part 5: Steady-state temperature humidity bias life test
Part 6: Storage at high temperature
Part 7: Internal moisture content measurement and the analysis of other residual gases
Part 8: Sealing
Part 9: Permanence of marking
Part 10: Mechanical shock
Part 11: Rapid change of temperature – Two-fluid-bath method
Part 12: Vibration, variable frequency
Part 13: Salt atmosphere
Part 14: Robustness of terminations (lead integrity)
Part 15: Resistance to soldering temperature for through-hole mounted devices
Part 16: Particle impact noise detection (PIND)
Part 17: Neutron irradiation
Part 18: Ionizing radiation (total dose)
Part 19: Die shear strength
Part 20: Resistance of plastic-encapsulated SMDs to the combined effect of moisture and
soldering heat
Part 21: Solderability
Part 22: Bond strength
Part 23: High temperature operating life
Part 24: Accelerated moisture resistance – Unbiased HAST
Part 25: Temperature cycling
Part 26: Electrostatic discharge (ESD) sensitivity testing – Human body model (HBM)
Part 27: Electrostatic discharge (ESD) sensitivity testing – Machine model (MM)
1
Part 28: Electrostatic discharge (ESD) sensitivity testing – Charged device model (CDM)
———————
1
To be published

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60749-21  IEC:2005 – 11 –
Part 29: Latch-up test
Part 30: Preconditioning of non-hermetic surface mount devices prior to reliability testing
Part 31: Flammability of plastic-encapsulated devices (internally induced)
Part 32: Flammability of plastic-encapsulated devices (externally induced)
Part 33: Accelerated moisture resistance – Unbiased autoclave
Part 34: Power cycling
2
Part 35: Acoustic microscopy for plastic encapsulated electronic components
Part 36: Acceleration, steady state
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.

———————
2
To be published

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60749-21  IEC:2005 – 13 –
SEMICONDUCTOR DEVICES –
MECHANICAL AND CLIMATIC TEST METHODS –

Part 21: Solderability


1 Scope
This part of IEC 60749 establishes a standard procedure for determining the solderability of
device package terminations that are intended to be joined to another surface using tin-lead
(SnPb) or lead-free (Pb-free) solder for the attachment.
This test method provides a procedure for ‘dip and look’ solderability testing of through hole,
axial and surface mount devices (SMDs) as well as an optional procedure for a board
mounting solderability test for SMDs for the purpose of allowing simulation of the soldering
process to be used in the device application. The test method also provides optional
conditions for ageing.
This test is considered destructive unless otherwise detailed in the relevant specification.
NOTE 1 This test method is in general accord with IEC 60068, but due to specific requirements of semi-
conductors, the following text is applied.
NOTE 2 This test method does not assess the effect of thermal stresses which may occur during the soldering
process. Reference should be made IEC 60749-15 or IEC 60749-20.
NOTE 3 This mechanical and climatic test method as it relates to solderability, is a complete rewrite of the test
contained in Subclause 2.1 of Chapter 2 of IEC 60749 (1996).
2 Test apparatus
This test method requires the following equipment.
2.1 Solder bath
The solder bath shall be not less than 40 mm in depth and not less than 300 ml in volume
such that it can contain at least 1 kg of solder. The apparatus shall be capable of maintaining
the solder at the specified temperature within ±5 °C.
2.2 Dipping device
A mechanical dipping device capable of controlling the rates of immersion and emersion of
the terminations and providing a dwell time (time of total immersion to the required depth) in
the solder bath as specified shall be used.
2.3 Optical equipment
An optical microscope capable of providing magnification inspection from 10× to 20× shall be
used.

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60749-21  IEC:2005 – 15 –
2.4 Steam ageing equipment
A non-corrodible container and cover of sufficient size to allow the placement of specimens
inside the vessel shall be used. The specimens shall be placed such that the lowest portion of
the specimen is a minimum of 40 mm above the surface of the water. A suitable method of
supporting the specimens shall be improvised using non-contaminating material.
NOTE During steam ageing, the test devices should be located in a manner so as to prevent water (steam
condensate) from dripping on them.
2.5 Lighting equipment
A lighting system shall be used that will provide a uniform, non-glare, non-directional
illumination of the specimen.
2.6 Materials
2.6.1 Flux
Unless otherwise detailed in the relevant specification, the flux shall consist of 25 % by weight
colophony in 75 % by weight of a 99,5 % (min.) by weight 2-propanol (issopropanol) solvent.
The specific gravity of the flux shall be maintained within the range of 0,838 to 0,913 at 25 °C.
The specification shall be as follows:
Colophony
Colour To WW colour specification or paler
Acid value (mg KOH/g colophony) 155 (minimum)
Softening point (ball and ring) 70 °C (minimum)
Flow point (Ubbelohde) 76 °C (minimum)
Ash 0,05 % (maximum).
Solubility A solution of the colophony in an equal part by weight
of 2-propanol (isopropanol) shall be clear, and after a
week at room temperature there shall be no sign of a
deposit.
2-propanol (isopropanol)
Purity Minimum 99,5 % 2-propanol (isopropanol) by weight
Acidity as acetic acid Maximum 0,002 % weight (other than carbon dioxide)
Non-volatile matter Maximum 2 mg per 100 ml.
2.6.2 Solder
2.6.2.1 Tin-lead
Unless otherwise detailed in the relevant specification, the solder specification for SnPb shall
be as follows:

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60749-21  IEC:2005 – 17 –
Chemical composition
The composition in percentage by weight shall be as follows:
Tin 59 % to 61 %
Antimony 0,5 % maximum
Copper 0,1 % maximum
Arsenic 0,05 % maximum
Iron 0,02 % maximum
Lead the remainder.
The solder shall not contain such impurities as aluminium, zinc or cadmium in amounts which
will adversely affect the properties of the solder.
Melting temperature range
The melting temperature range of the 60 % solder is as follows:
Co
...