Already a subscriber? 
MADCAD.com Free Trial
Sign up for a 3 day free trial to explore the MADCAD.com interface, PLUS access the
2009 International Building Code to see how it all works.
If you like to setup a quick demo, let us know at support@madcad.com
or +1 800.798.9296 and we will be happy to schedule a webinar for you.
Security check
Please login to your personal account to use this feature.
Please login to your authorized staff account to use this feature.
Are you sure you want to empty the cart?
PD IEC/TS 62647-2:2012 Process management for avionics. Aerospace and defence electronic systems containing lead-free solder - Mitigation of deleterious effects of tin, 2013
- 30276310-VOR.pdf [Go to Page]
- CONTENTS
- FOREWORD
- INTRODUCTION
- 1 Scope
- 2 Normative references
- 3 Terms, definitions and abbreviations [Go to Page]
- 3.1 Terms and definitions
- 3.2 Abbreviations
- 4 Technical requirement [Go to Page]
- 4.1 Control level requirements [Go to Page]
- 4.1.1 General
- 4.1.2 Control levels and levels of integration
- 4.1.3 COTS and level selection
- 4.1.4 Other level selection information
- 4.2 Requirements for control levels [Go to Page]
- 4.2.1 Control level 1 requirements
- 4.2.2 Control level 2A requirements
- 4.2.3 Control level 2B requirements
- 4.2.4 Control level 2C requirements
- 4.2.5 Control level 3 requirements
- 4.2.6 Requirements for mitigating tin whisker risk for solder joints
- 4.3 Implementation methods [Go to Page]
- 4.3.1 Flowing requirements to lower level suppliers (applies to control level 2B, control level 2C, and control level 3)
- 4.3.2 Detecting and controlling Pb-free tin finish introduction
- 4.3.3 Sample monitoring plans (applies to control level 2B and control level 2C)
- 4.3.4 Lot monitoring requirements (applies to control level 3)
- 4.4 Methods for mitigating impact of Pb-free tin (applies to control level 2B, control level 2C) [Go to Page]
- 4.4.1 General
- 4.4.2 Hard potting and encapsulation
- 4.4.3 Physical barriers
- 4.4.4 Conformal and other coats
- 4.4.5 SnPb soldering process with validated coverage
- 4.4.6 Circuit and design analysis
- 4.5 Part selection process
- 4.6 Assessment and documentation of risk and mitigation effectiveness [Go to Page]
- 4.6.1 General
- 4.6.2 Elements of assessment
- 4.6.3 Other risk analysis issues
- Annex A (informative) Guidance on control levels, risk assessment, and mitigation evaluation
- Annex B (informative) Technical guide on detection methods, mitigation methods, and methods for limiting impact of tin
- Annex C (informative) Tin whisker inspection
- Annex D (informative) Analysis and risk assessment guidance
- Annex E (informative) Whiskers growing from solder joint fillets and bulk solder
- Bibliography
- Figures [Go to Page]
- Figure A.1 – Decision tree
- Figure A.2 – Decision tree, sub-tree 1
- Figure A.3 – Decision tree, sub-tree 2
- Figure B.1 – Insufficient solder flow
- Figure C.1 – Equipment setup for whisker examination
- Figure C.2 – Whiskers examination areas and direction
- Figure C.3 – Side-illumination by flexible light
- Figure C.4 – Coating residuals and dusts attached on lead-frame with conformal coating
- Figure C.5 – Comparisons between whisker observations by microscope and SEM
- Figure C.6 – Limitation of microscope observation
- Figure C.7 – Preliminary whisker examination in non-coated test specimens
- Figure E.1 – Whiskers and hillocks formed after 500 hours of storage at 85 °C / 85 % RH followed by –55 °C to 85 °C air to air cycling, 1 000 cycles
- Figure E.2 – Long whisker growing from SAC405 no-clean assembly reported by Terry Munson (Foresite)
- Figure E.3 – Whiskers and hillocks protruding through flux residueand growing from solder free of the flux residue [87]
- Figure E.4 – Tin whisker length impact by ionic cleanliness
- Figure E.5 – Tin whisker density impact by ionic cleanliness
- Figure E.6 – Whisker length depending on component and assembly cleanliness
- Figure E.7 – Microstructures of solder fillet with 0,8 % HBr activated flux assembled in air after 1 000 hours at 85 °C / 85 % RH
- Figure E.8 – The mechanism of Sn whisker formation on solder fillet induced by oxidation
- Figure E.9 – SAC105 bulk solder at ambient T in nitrogen chamber [34]
- Tables [Go to Page]
- Table A.1 – Control level summary table (1 of 2)
- Table B.1 – Conformal coating material physical properties from S. Meschter [10]
- Table B.2 – Conformal coating physical properties from T. Woodrow [12]
- Table B.3 – Conformal coating physical properties from R. Kumar [13] [Go to Page]
