IEC 60749-20:2008

Semiconductor devices - Mechanical and climatic test methods - Part 20: Resistance of plastic encapsulated SMDs to the combined effect of moisture and soldering heat

IEC 60749-20:2008 provides a means of assessing the resistance to soldering heat of semiconductors packaged as plastic encapsulated surface mount devices (SMDs). This test is destructive. This second edition cancels and replaces the first edition published in 2002 and constitutes a technical revision. The main changes are as follows:
- to reconcile certain classifications of IEC 60749-20 and those of IPC/JEDEC J-STD-020C;
- reference IEC 60749-35 instead of Annex A of IEC 60749-20, Edition 1;
- update for lead-free solder;
- correct certain errors in the original Edition 1.

Dispositifs à semiconducteurs - Méthodes d'essais mécaniques et climatiques - Partie 20: Résistance des CMS à boîtier plastique à l'effet combiné de l'humidité et de la chaleur de brasage

La CEI 60749-20:2008 fournit des moyens d'évaluer la résistance à la chaleur de brasage des semiconducteurs sous emballage comme les composants à boîtier plastique à montage en surface (CMS). Cet essai est destructif. Cette seconde édition annule et remplace la première édition publiée en 2002 et constitue une révision technique. Les principales modifications sont les suivantes:
- concilier certaines classifications de la CEI 60749-20 avec celles de l'IPC/JEDEC J-STD-020C;
- faire référence à la CEI 60749-35 à la place de l'annexe A de la CEI 60749-20 Edition 1;
- effectuer une mise à jour pour la brasure sans plomb;
- corriger certaines erreurs de l'Edition 1 originale.

General Information

• Status: Published
• Publication Date: 08-Dec-2008
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 31.080.01 - Semiconductor devices in general
• Technical Committee: TC 47 - Semiconductor devices
• Drafting Committee: WG 2 - TC 47/WG 2
• Current Stage: DELPUB - Deleted Publication
• Start Date: 01-May-2019
• Completion Date: 31-Aug-2020

Relations

• Revises: IEC 60749-20:2002 - Semiconductor devices - Mechanical and climatic test methods - Part 20: Resistance of plastic-encapsulated SMDs to the combined effect of moisture and soldering heat
• Effective Date: 05-Sep-2023
• Revises: IEC 60749-20:2002/COR1:2003 - Corrigendum 1 - Semiconductor devices - Mechanical and climatic test methods - Part 20: Resistance of plastic-encapsulated SMDs to the combined effect of moisture and soldering heat
• Effective Date: 05-Sep-2023
• Revised: IEC 60749-20:2020 - Semiconductor devices - Mechanical and climatic test methods - Part 20: Resistance of plastic encapsulated SMDs to the combined effect of moisture and soldering heat
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60749-20
Edition 2.0 2008-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Semiconductor devices – Mechanical and climatic test methods –
Part 20: Resistance of plastic encapsulated SMDs to the combined effect of
moisture and soldering heat
Dispositifs à semiconducteurs – Méthodes d'essais mécaniques et climatiques –
Partie 20: Résistance des CMS à boîtier plastique à l'effet combiné de l'humidité
et de la chaleur de brasage
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IEC 60749-20
Edition 2.0 2008-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Semiconductor devices – Mechanical and climatic test methods –
Part 20: Resistance of plastic encapsulated SMDs to the combined effect of
moisture and soldering heat
Dispositifs à semiconducteurs – Méthodes d'essais mécaniques et climatiques –
Partie 20: Résistance des CMS à boîtier plastique à l'effet combiné de l'humidité
et de la chaleur de brasage
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
U
CODE PRIX
ICS 31.080.01 ISBN 978-2-88910-284-6
– 2 – 60749-20 © IEC:2008
CONTENTS
FOREWORD.4
1 Scope.6
2 Normative references.6
3 General description.6
4 Test apparatus and materials.6
4.1 Humidity chamber.6
4.2 Reflow soldering apparatus.6
4.3 Holder .7
4.4 Wave-soldering apparatus .7
4.5 Solvent for vapour-phase reflow soldering.7
4.6 Flux.7
4.7 Solder .7
5 Procedure.7
5.1 Initial measurements .7
5.1.1 Visual inspection.7
5.1.2 Electrical measurement.8
5.1.3 Internal inspection by acoustic tomography .8
5.2 Drying.8
5.3 Moisture soak .8
5.3.1 General .8
5.3.2 Conditions for non-dry-packed SMDs .8
5.3.3 Moisture soak for dry-packed SMDs .8
5.4 Soldering heat .10
5.4.1 General .10
5.4.2 Method of heating by infrared convection or convection reflow
soldering.11
5.4.3 Method of heating by vapour-phase reflow soldering.12
5.4.4 Method of heating by wave-soldering.12
5.5 Recovery .13
5.6 Final measurements .14
5.6.1 Visual inspection.14
5.6.2 Electrical measurement.14
5.6.3 Internal inspection by acoustic tomography .14
6 Information to be given in the relevant specification.14
Annex A (informative) Details and descriptions of test method on resistance of plastic
encapsulated SMDs to the combined effect of moisture and soldering heat.16

Figure 1 – Method of measuring the temperature profile of a specimen.7
Figure 2 – Heating by wave-soldering .13
Figure A.1 – Process of moisture diffusion at 85 °C, 85 % RH.17
Figure A.2 – Definition of resin thickness and the first interface .17
Figure A.3 – Moisture soak time to saturation at 85 °C as a function of resin thickness .18
Figure A.4 – Temperature dependence of saturated moisture content of resin.18
Figure A.5 – Dependence of moisture content of resin at the first interface on resin
thickness under various soak conditions.19

60749-20 © IEC:2008 – 3 –
Figure A.6 – Dependence of moisture content of resin at the first interface on resin
thickness related to method A of moisture soak .20
Figure A.7 – Dependence of the moisture content of resin at the first interface on resin
thickness related to method B of moisture soak .21
Figure A.8 – Dependence of moisture content of resin at the first interface on resin
thickness related to condition B2 of method B of moisture soak .21
Figure A.9 – Temperature profile of infrared convection and convection reflow soldering
for Sn-Pb eutectic assembly.23
Figure A.10 – Temperature profile of infrared convection and convection reflow
soldering for lead-free assembly.23
Figure A.11 – Classification profile .25
Figure A.12 – Temperature profile of vapour-phase soldering (condition II-A).25
Figure A.13 – Immersion method into solder bath .26
Figure A.14 – Relation between the infrared convection reflow soldering and wave-
soldering.26
Figure A.15 – Temperature in the body of the SMD during wave-soldering .27

Table 1 – Moisture soak conditions for non-dry-packed SMDs .8
Table 2 – Moisture soak conditions for dry-packed SMDs (method A) .9
Table 3 – Moisture soak conditions for dry-packed SMDs (method B) .10
Table 4 – SnPb eutectic process – Classification reflow temperatures .11
Table 5 – Pb-free process – Classification reflow temperatures .12
Table 6 – Heating condition for vapour-phase soldering .12
Table 7 – Immersion conditions for wave-soldering.13
Table A.1 – Comparison of actual storage conditions and equivalent moisture soak

conditions before soldering heat.18
Table A.2 – Classification profiles.24

– 4 – 60749-20 © IEC:2008
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SEMICONDUCTOR DEVICES –
MECHANICAL AND CLIMATIC TEST METHODS –

Part 20: Resistance of plastic encapsulated SMDs to
the combined effect of moisture and soldering heat

FOREWORD
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