SIST EN 50390:2007

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.VSRMHYRaumfahrt-Produktsicherung - Handlöten elektrischer Verbindungen hoher ZuverlässigkeitConformité pour les produits spatiaux - Manuel de soudabilité des connexions électriques de haute fiabilitéSpace product assurance - The manual soldering of high-reliability electrical connections49.060Aerospace electric equipment and systems25.160.50Trdo in mehko lotanjeBrazing and solderingICS:Ta slovenski standard je istoveten z:EN 50390:2004SIST EN 50390:2007en01-januar-2007SIST EN 50390:2007SLOVENSKI
STANDARD



SIST EN 50390:2007



EUROPEAN STANDARD
EN 50390 NORME EUROPÉENNE EUROPÄISCHE NORM
July 2004 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
© 2004 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50390:2004 E
ICS 49.060
English version
Space product assurance –
The manual soldering of high-reliability electrical connections
Conformité pour les produits spatiaux - Manuel de soudabilité des connexions électriques de haute fiabilité
Raumfahrt-Produktsicherung –
Handlöten elektrischer Verbindungen hoher Zuverlässigkeit
This European Standard was approved by CENELEC on 2004-04-01. 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 two official versions (English, 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.
SIST EN 50390:2007



EN 50390:2004 - 2 -
Foreword This European Standard has been prepared by the former CENELEC BTTF 91-3, Space equipment standardization, the work of which has been transferred by 113 BT to CENELEC TC 107X, Process management for avionics. It is based on a previous version 1) originally prepared by the ECSS Product Assurance Working Group, reviewed by the ECSS Technical Panel and approved by the ECSS Steering Board. The European Cooperation for Space Standardization (ECSS) is a cooperative effort of the European Space Agency, National Space Agencies and European industry associations for the purpose of developing and maintaining common standards. This European Standard is one of the series of space standards intended to be applied together for the management, engineering and product assurance in space projects and applications. Requirements in this European Standard are defined in terms of what shall be accomplished, rather than in terms of how to organize and perform the necessary work. This allows existing organizational structures and methods to be applied where they are effective, and for the structures and methods to evolve as necessary without rewriting the standards. The formulation of this European Standard takes into account the existing ISO 9000 family of documents. The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50390 on 2004-04-01. 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) 2005-04-01
- latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2007-04-01
——————— 1) ECSS-Q-70-08A. SIST EN 50390:2007



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Contents Page Introduction.8 1 Scope.8 2 Normative references.8 3 Terms, definitions and abbreviated terms.9 3.1 Terms and definitions.9 3.2 Abbreviated terms.17 4 Principles and prerequisites of reliable soldered connections.17 4.1 Principles.17 4.2 Prerequisites.18 5 Preparatory conditions.18 5.1 Facility cleanliness.18 5.2 Environmental conditions.19 5.3 Precautions against static charges.19 5.4 Lighting requirements.19 5.5 Equipment and tools.20 5.5.1 Brushes.20 5.5.2 Files.20 5.5.3 Cutters and pliers.20 5.5.4 Bending tools.20 5.5.5 Clinching tools.21 5.5.6 Insulation strippers.21 5.5.7 Soldering irons and resistance soldering equipment.21 5.5.8 Non-contact heat sources.21 5.5.9 Soldering tools.22 5.5.10 Defective or uncalibrated equipment or tools.22 6 Materials selection.22 6.1 Solder.22 6.1.1 Form.22 6.1.2 Composition.22 6.1.3 Melting temperatures and choice.22 6.2 Flux.22 6.2.1 Rosin-based fluxes.22 6.2.2 Corrosive acid fluxes.23 6.3 Solvents.24 6.3.1 Acceptable solvents.24 6.3.2 Drying.24 6.4 Flexible insulation materials.24 6.5 Terminals.24 6.5.1 Preferred terminals.24 6.5.2 Tin-, silver- and gold-plated terminals.24 6.5.3 Shape of terminals.25 6.6 Wires.25 6.7 PCBs.25 6.7.1 Boards.25 6.7.2 Plated-through holes.25 SIST EN 50390:2007



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6.7.3 Tin-lead finish on conductors.25 6.7.4 Gold finish on conductors.25 6.8 Conformal coating, staking compounds and potting materials.25 7 Preparation for soldering.26 7.1 Preparation of conductors, terminals and solder cups.26 7.1.1 Insulation removal.26 7.1.2 Damage to insulation.26 7.1.3 Damage to conductors.26 7.1.4 Insulation clearance.26 7.1.5 Surface to be soldered.26 7.1.6 De-golding and pre-tinning of conductors.27 7.2 Preparation of the soldering bit.27 7.2.1 Inspection.27 7.2.2 Maintenance.27 7.2.3 Copper bits for special soldering applications.28 7.2.4 Plated bits.28 7.2.5 Tip in operation.28 7.3 Maintenance of resistance-type soldering electrodes.28 7.4 Handling (work station).28 7.5 Storage (work station).28 7.5.1 Components.28 7.5.2 PCBs.28 7.5.3 Materials requiring segregation.28 7.5.4 Traceability.28 7.6 Baking of PCBs.28 8 Mounting of components.29 8.1 General requirements.29 8.1.1 Introduction.29 8.1.2 Heavy components.29 8.1.3 Metal-case components.29 8.1.4 Glass-encased components.29 8.1.5 Stress relief.29 8.1.6 Reinforced plated-through holes.31 8.1.7 Lead and conductor cutting.31 8.1.8 Heat-generating components.31 8.1.9 Moulded components.31 8.1.10 Hook-up wire.31 8.1.11 Location.31 8.1.12 Conformal coating, cementing and encapsulation.31 8.2 Lead bending requirements.31 8.2.1 General.31 8.2.2 Components with leads terminating on the opposite side of a PCB.32 8.2.3 Components with leads terminating on the same side of a PCB.32 8.2.4 Conductors terminating on both sides of a non-plated-through hole.32 8.2.5 Non-bendable leads.33 8.3 Mounting of terminals to PCB.33 8.3.1 General.33 8.3.2 Methods of attachment.33 SIST EN 50390:2007



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8.4 Lead attachment to PCBs.34 8.4.1 General.34 8.4.2 Lead access holes.34 8.4.3 Clinched leads.36 8.4.4 Stud leads.36 8.4.5 Lapped round leads.37 8.4.6 Lapped ribbon leads.37 8.4.7 Lapped round- and ribbon-lead parts with solder connection on same side.38 8.5 Mounting of components to terminals.39 8.5.1 General.39 8.5.2 Special constraints.39 8.6 Cordwood modules.40 8.7 Mounting of connectors to PCBs.40 8.7.1 General.40 8.7.2 Special constraints.40 9 Attachment of conductors to terminals, solder cups and cables.41 9.1 General.41 9.1.1 Conductors.41 9.1.2 Terminals.41 9.1.3 Component leads.41 9.2 Wire termination.41 9.2.1 Breakouts from cables.41 9.2.2 Minimum and maximum insulation clearance.41 9.2.3 Multiple parallel entry.41 9.2.4 Variations.41 9.2.5 Solid hook-up wire.41 9.2.6 Stress relief.41 9.2.7 Mechanical support.41 9.3 Turret and straight pin terminals.42 9.3.1 Side route.42 9.3.2 Bottom route.42 9.4 Bifurcated terminals.43 9.4.1 General.43 9.4.2 Bottom route.43 9.4.3 Side route.44 9.4.4 Top route.45 9.4.5 Combination of top and bottom routes.45 9.4.6 Combination of side and bottom routes.45 9.5 Hook terminals.45 9.6 Pierced terminals.45 9.7 Solder cups (connector type).47 9.8 Insulation tubing application.47 9.9 Wire and cable interconnections.47 9.9.1 General.47 9.9.2 Preparation of wires.47 9.9.3 Preparation of shielded wires and cables.48 9.9.4 Pre-assembly.48 9.9.5 Soldering procedures.48 SIST EN 50390:2007



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9.9.6 Cleaning.49 9.9.7 Inspection.49 9.9.8 Workmanship.49 9.9.9 Sleeving of interconnection.49 9.10 Connection of stranded wires to PCBs.49 10 Soldering to terminals and PCBs.51 10.1 General.51 10.1.1 Securing conductors.51 10.1.2 Insulation sleeving, potting or coating.51 10.1.3 Thermal shunts.51 10.1.4 High-voltage connections.51 10.2 Solder application to terminals.51 10.2.1 Soldering of swaged terminals onto PCBs.51 10.2.2 Soldering of conductors onto terminals (except cup).51 10.2.3 Soldering of conductors onto cup terminals.51 10.3 Solder application to PCB.51 10.3.1 Solder coverage.51 10.3.2 Solder fillets.52 10.3.3 Soldering of component leads to plated-through holes.52 10.3.4 Solder application.52 10.4 Wicking.52 10.5 Solder rework.52 11 Cleaning of PCB assemblies.52 11.1 General.52 11.2 Ultrasonic cleaning.52 11.3 Monitoring for cleanliness.53 11.3.1 Cleanliness testing.53 11.3.2 Testing frequency.53 11.3.3 Test limits.53 11.3.4 Test methods.53 12 Final inspection.54 12.1 General.54 12.2 Acceptance criteria.54 12.3 Rejection criteria.54 13 Verification.55 13.1 General.55 13.2 Temperature cycling.55 13.3 Vibration.55 14 Quality assurance.56 14.1 General.56 14.2 Data.56 14.3 Non-conformance.56 14.4 Calibration.56 14.5 Traceability.56 14.6 Workmanship standards.56 14.7 Inspection.56 14.8 Operator and inspector training and certification.57 Annex A (informative) Typical satisfactory and unsatisfactory solder connections.58 SIST EN 50390:2007



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Figures Figure 1 — Profiles of correct and incorrect cutters for trimming leads.20 Figure 2 — Non-approved types of mechanical strippers.21 Figure 3 — Stress relieved component terminations on PCB.30 Figure 4 — Minimum lead bend.32 Figure 5 — Component and solder termination on the same side.32 Figure 6 — Leads with solder termination on both sides.33 Figure 7 — Types of terminal swaging.34 Figure 8 — Clinched-lead terminations - unsupported holes.35 Figure 9 — Clinched lead terminations - plated through-holes.35 Figure 10 — Stud terminations.37 Figure 11 — Through-hole lapped terminations.38 Figure 12 — Design dimensions for single-surface lapped terminations.39 Figure 13 — Method of stress relieving parts attached to terminals.40 Figure 14 — Side- and bottom-route connections to turret terminals.42 Figure 15 — Bottom-route connections to bifurcated terminal.43 Figure 16 — Side-route connection to bifurcated terminal.44 Figure 17 — Top-route connection to bifurcated terminal.45 Figure 18 — Connections to hook terminals.46 Figure 19 — Connections to pierced terminals.46 Figure 20 — Connections to solder cups (connector type).47 Figure 21 — Methods for securing wires.49 Figure 22 — Stranded wires to PCBs.50 Figure A.1 — Soldered clinched terminals.58 Figure A.2 — Soldered stud terminals.59 Figure A.3 — Soldered turret terminals.60 Figure A.4 — Soldered turret terminals.61 Figure A.5 — Soldered bifurcated terminals.62 Figure A.6 — Soldered hook terminals.63 Figure A.7 — Soldered cup terminals.64 Figure A.8 — Hand-soldered wire to shielded cable interconnections.65 Figure A.9 — Hand-soldered wire to shielded wire interconnections.66 Figure A.10 — Hand-soldered wire interconnections – details of defects.67 Tables Table 1 — Chemical composition of spacecraft solders.23 Table 2 — Guide to choice of solder types.
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