BS EN IEC 60749-20:2020
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Semiconductor devices. Mechanical and climatic test methods – Resistance of plastic encapsulated SMDs to the combined effect of moisture and soldering heat
| Published By | Publication Date | Number of Pages |
| BSI | 2020 | 32 |
IEC 60749-20:2020 is available as IEC 60749-20:2020 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 60749-20:2020 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 edition includes the following significant technical changes with respect to the previous edition: – incorporation of a technical corrigendum to IEC 60749-20:2008 (second edition ); – inclusion of new Clause 3; – inclusion of explanatory notes.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 2 | undefined |
| 5 | Annex ZA(normative)Normative references to international publicationswith their corresponding European publications |
| 6 | English CONTENTS |
| 8 | FOREWORD |
| 10 | 1 Scope 2 Normative references 3 Terms and definitions |
| 11 | 4 General description 5 Test apparatus and materials 5.1 Humidity chamber |
| 12 | 5.2 Reflow soldering apparatus 5.3 Holder 5.4 Wave-soldering apparatus 5.5 Solvent for vapour-phase reflow soldering 5.6 Flux 5.7 Solder Figures Figure 1 – Method of measuring the temperature profile of a specimen |
| 13 | 6 Procedure 6.1 Initial measurements 6.1.1 Visual inspection 6.1.2 Electrical measurement 6.1.3 Internal inspection by acoustic tomography 6.2 Drying 6.3 Moisture soak 6.3.1 General 6.3.2 Conditions for non-dry-packed SMDs Tables Table 1 – Moisture soak conditions for non-dry-packed SMDs |
| 14 | 6.3.3 Moisture soak for dry-packed SMDs Table 2 – Moisture soak conditions for dry-packed SMDs (method A) |
| 15 | 6.4 Soldering heat 6.4.1 General Table 3 – Moisture soak conditions for dry-packed SMDs (method B) |
| 16 | 6.4.2 Method of heating by infrared convection or convection reflow soldering Table 4 – SnPb eutectic process – Classification reflow temperatures (Tc) |
| 17 | 6.4.3 Method of heating by vapour-phase reflow soldering 6.4.4 Method of heating by wave-soldering Table 5 – Pb-free process – Classification reflow temperatures (Tc) Table 6 – Heating condition for vapour-phase soldering |
| 18 | 6.5 Recovery Figure 2 – Heating by wave-soldering Table 7 – Immersion conditions for wave-soldering |
| 19 | 6.6 Final measurements 6.6.1 Visual inspection 6.6.2 Electrical measurement 6.6.3 Internal inspection by acoustic tomography 7 Information to be given in the relevant specification |
| 21 | Annex A (informative) Details and description of test method on resistance of plastic encapsulated SMDs to the combined effect of moisture and soldering heat A.1 Description of moisture soak A.1.1 Guidance for moisture soak A.1.2 Considerations on which the condition of moisture soak is based |
| 22 | Figure A.1 – Process of moisture diffusion at 85 °C, 85 % RH Figure A.2 – Definition of resin thickness and the first interface Figure A.3 – Moisture soak time to saturation at 85 °C as a function of resin thickness |
| 23 | Figure A.4 – Temperature dependence of saturated moisture content of resin Table A.1 – Comparison of actual storage conditions and equivalent moisture soak conditions before soldering heat |
| 24 | Figure A.5 – Dependence of moisture content of resin at the first interface on resin thickness under various soak conditions Figure A.6 – Dependence of moisture content of resin at the first interface on resin thickness related to method A of moisture soak |
| 25 | Figure A.7 – Dependence of the moisture content of resin at the first interface on resin thickness related to method B of moisture soak |
| 26 | A.2 Procedure for moisture content measurement 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 |
| 27 | A.3 Soldering heat methods A.3.1 Temperature profile of infrared convection and convection reflow soldering Figure A.9 – Temperature profile of infrared convection and convection reflow soldering for Sn-Pb eutectic assembly |
| 28 | Figure A.10 – Temperature profile of infrared convection and convection reflow soldering for lead-free assembly Table A.2 – Classification profiles |
| 29 | A.3.2 Temperature profile of vapour-phase soldering Figure A.11 – Classification profile Figure A.12 – Temperature profile of vapour-phase soldering (condition II-A) |
| 30 | A.3.3 Heating method by wave-soldering Figure A.13 – Immersion method into solder bath |
| 31 | Figure A.14 – Relation between the infrared convection reflow soldering and wave-soldering Figure A.15 – Temperature in the body of the SMD during wave-soldering |
