ESA UNCLASSIFIED - For Official Use estec European Space Research and Technology Centre Keplerlaan 1 2201 AZ Noordwijk The Netherlands T +31 (0)71 565 6565 F +31 (0)71 565 6040 www.esa.int REQUIREMENT DOCUMENT / SPECIFICATION (SYSTEM, SUBSYSTEM, UNIT, EQUIPMENT LEVEL) High reliability assembly for surface mount and through hole connections Prepared by Ana Brandao ESA Reference ESA-TECMSP-RS-014795 Issue/Revision 1.0 Date of Issue 23/08/2019 Status Approved ESA UNCLASSIFIED - For Official Use APPROVAL Title High reliability assembly for surface mount and through hole connections Issue Number 1 Revision Number 0 Author Ana Brandao (TEC-MSP) Date 23/08/2019 Approved By Thomas Rohr (TEC-MSP) Date of Approval CHANGE LOG Reason for change Issue Nr. Revision Number Date CHANGE RECORD Issue Number 1 Revision Number 0 Reason for change Date Pages Paragraph(s) DISTRIBUTION Name/Organisational Unit Page 2/219 High reliability assembly for surface mount and through hole connections Issue Date 23/08/2019 Ref ESA-TECMSP-RS-014795 ESA UNCLASSIFIED - For Official Use Table of contents Change log .................................................................................................................. 3 Table of contents ........................................................................................................ 4 Introduction ............................................................................................................... 16 1 Scope ...................................................................................................................... 23 2 Normative references ............................................................................................ 24 3 Terms, definitions and abbreviated terms .......................................................... 26 3.1 Terms from other standards ..................................................................................... 26 3.2 Terms specific to the present standard .................................................................... 26 3.3 Abbreviated terms .................................................................................................... 31 3.4 Nomenclature ........................................................................................................... 33 4 Principles of reliable soldered connections ....................................................... 34 5 Preparatory conditions ......................................................................................... 35 5.1 Calibration ................................................................................................................ 35 5.2 Facility cleanliness ................................................................................................... 35 5.3 Environmental conditions ......................................................................................... 35 5.4 Lighting requirements ............................................................................................... 36 5.5 Precautions against static discharges ...................................................................... 36 5.5.1 Overview ..................................................................................................... 36 5.5.2 General ....................................................................................................... 37 5.5.3 ESD Protected Area ................................................................................... 37 5.5.4 Precautions against ESD during manufacturing ......................................... 37 5.5.5 Protective packaging and ESD protection .................................................. 38 5.6 Equipment and tools ................................................................................................. 39 5.6.1 General ....................................................................................................... 39 5.6.2 Brushes ...................................................................................................... 40 5.6.3 Cutters and pliers ....................................................................................... 40 5.6.4 Bending tools .............................................................................................. 40 5.6.5 Clinching tools ............................................................................................ 41 5.6.6 Insulation strippers ..................................................................................... 41 Page 3/219 High reliability assembly for surface mount and through hole connections Issue Date 23/08/2019 Ref ESA-TECMSP-RS-014795 ESA UNCLASSIFIED - For Official Use 5.6.7 Hot air blower ............................................................................................. 42 5.6.8 Soldering tools ............................................................................................ 42 5.6.9 Baking and curing ovens ............................................................................ 44 5.6.10 Solder deposition equipment ...................................................................... 44 5.6.11 Automatic component placement equipment ............................................. 44 5.6.12 Dynamic wave-solder machines ................................................................. 45 5.6.13 Selective wave solder equipment ............................................................... 45 5.6.14 Condensation (vapour phase) reflow machines ......................................... 46 5.6.15 Local hot gas reflow machines ................................................................... 47 5.6.16 Forced convection and infrared reflow systems ......................................... 47 5.6.17 Other equipment for reflow soldering .......................................................... 47 5.6.18 Cleanliness testing equipment .................................................................... 47 5.6.19 Automatic Optical Inspection (AOI) equipment ........................................... 48 5.6.20 X-ray inspection equipment ........................................................................ 48 6 Material selection .................................................................................................. 49 6.1 General ..................................................................................................................... 49 6.2 Solder ....................................................................................................................... 49 6.2.1 Form ........................................................................................................... 49 6.2.2 Composition ................................................................................................ 50 6.2.3 Solder paste ............................................................................................... 50 6.2.4 Maintenance of paste purity ....................................................................... 52 6.3 Flux ........................................................................................................................... 52 6.3.1 Rosin based fluxes ..................................................................................... 52 6.3.2 Application of flux ....................................................................................... 53 6.3.3 Flux controls for wave-soldering equipment ............................................... 53 6.4 Solvents .................................................................................................................... 54 6.5 Flexible insulation materials ..................................................................................... 54 6.6 Terminals .................................................................................................................. 55 6.6.1 Materials ..................................................................................................... 55 6.6.2 Tin, silver and gold-plated terminals ........................................................... 55 6.7 Wires ........................................................................................................................ 55 6.8 Sculptured flex .......................................................................................................... 56 6.9 Printed circuits substrates ........................................................................................ 56 6.9.1 Substrates selection ................................................................................... 56 6.9.2 Gold finish on PCBs footprint ...................................................................... 56 6.10 Components ............................................................................................................. 56 6.10.1 General ....................................................................................................... 56 Page 4/219 High reliability assembly for surface mount and through hole connections Issue Date 23/08/2019 Ref ESA-TECMSP-RS-014795 ESA UNCLASSIFIED - For Official Use 6.10.2 Moisture sensitive components .................................................................. 57 6.11 Adhesives, potting, underfill and conformal coatings ............................................... 57 7 Preparations prior to mounting and soldering ................................................... 59 7.1 General ....................................................................................................................