SIST EN 50390:2007

Space product assurance - The manual soldering of high-reliability electrical connections

This standard defines the technical requirements and quality assurance provisions for the manual soldering of high­reliability electrical connections intended for use in spacecraft and associated equipment.
The rigorous requirements set by this standard ensure the high reliability of hand­soldered electrical connections intended to withstand normal terrestrial conditions and the vibrational G­loads and environment imposed by space flight. The proper tools, correct materials, design and workmanship are covered by this standard. Acceptance and rejection criteria are stated and some workmanship standards are included to discriminate between proper and improper work.
Wave­soldering processes and surface mount technologies are specified in separate documents, and those processes require to be verified as prescribed in the respective standard.

Raumfahrt-Produktsicherung - Handlöten elektrischer Verbindungen hoher Zuverlässigkeit

Conformité pour les produits spatiaux - Manuel de soudabilité des connexions électriques de haute fiabilité

Zagotavljanje vesoljskih izdelkov - Ročno spajkanje visoko zanesljivih električnih spojev

General Information

• Status: Published
• Publication Date: 31-Dec-2006
• ICS: 25.160.50 - Brazing and soldering
• ICS: 49.060 - Aerospace electric equipment and systems
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Jan-2007
• Due Date: 01-Jan-2007
• Completion Date: 01-Jan-2007
• Ref Project: EN 50390:2004 - Space product assurance - The manual soldering of high-reliability electrical connections

Overview

EN 50390:2004 - Space product assurance: The manual soldering of high‑reliability electrical connections (CLC) - defines technical requirements and quality assurance provisions for manual soldering of high‑reliability electrical connections used in spacecraft and associated equipment. It focuses on ensuring that hand‑soldered joints withstand normal terrestrial handling and the vibrational G‑loads and harsh environments of space flight. The standard covers tools, materials, design, workmanship, acceptance/rejection criteria and traceability. Wave‑soldering and surface‑mount processes are excluded and governed by separate standards.

Key topics and technical requirements

EN 50390 details practical and inspectable requirements across the soldering process, including:

• Principles and prerequisites for reliable soldered connections (design and process intent).
• Preparatory conditions: facility cleanliness, environmental controls, ESD precautions, lighting and workstation handling.
• Equipment and tools: soldering irons, resistance soldering, non‑contact heaters, tool maintenance and calibration.
• Materials selection: solder forms and compositions, flux types (rosin vs corrosive), acceptable solvents and drying, insulation and terminal finishes.
• PCB and component considerations: printed circuit board prep, plated‑through holes, tin/gold finishes and baking procedures.
• Component mounting and lead preparation: lead bending, clinching, stress relief, heavy/heat‑generating components and connector mounting.
• Wire terminations and attachment methods: solder cups, turret and pin terminals, bifurcated and hook terminals, insulation clearance and strain relief.
• Workmanship, inspection and acceptance criteria: visual workmanship standards to discriminate proper vs improper soldering and stated acceptance/rejection rules.
• Traceability and storage: component/material segregation, labeling and record keeping for product assurance.

Practical applications and users

EN 50390 is intended for organizations and personnel involved in the manufacture, assembly, inspection and procurement of spacecraft‑grade electronic assemblies. Typical users include:

• Aerospace and satellite manufacturers
• Product assurance / QA engineers for space projects
• PCB assemblers and hand‑solder technicians working on flight hardware
• Design engineers specifying soldering requirements for harnesses, connectors and boards
• Procurement teams selecting materials and processes compliant with space standards

Using this standard improves reliability of hand‑soldered electrical connections, reduces rework, and supports compliance with space project product assurance requirements.

Related standards

• EN 50390:2004 was based on earlier ECSS product assurance work (e.g., ECSS‑Q‑70‑08A).
• Wave‑soldering and surface‑mount technology (SMT) processes are addressed in separate standards and must be verified per those documents.

Keywords: manual soldering, space product assurance, high‑reliability electrical connections, spacecraft soldering, soldering workmanship, PCB soldering, solder, flux, ESD, acceptance criteria.

Standards Content (Sample)

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
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.
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

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

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.23 Table 3 — Insulation clearance.26 Table 4 — Dimensions for Figure 22.50 Table 5 — Cleanliness test values.54 Table 6 — Minimum severity for vibration testing.55
Introduction The main part of this standard is based on recommendations from the National Aeronautics and Space Administration, and European soldering technology experts. Modifications have been incorporated into the text to provide for the specific requirement of low-outgassing electrical systems which are required by scientific and application satellites. Other additions have been made in the light of recent technological advances and results of metallurgical test programmes. The methods and workmanship contained in this standard are considered to be fully approved for normal spacecraft requirements. 1 Scope This standard defines the technical requirements and quality assurance provisions for the manual soldering of high-reliability electrical connections intended for use in spacecraft and associated equipment. The rigorous requirements set by this standard ensure the high reliability of hand-soldered electrical connections intended to withstand normal terrestrial conditions and the vibrational G-loads and environment imposed by space flight. The proper tools, correct materials, design and workmanship are covered by this standard. Acceptance and rejection criteria are stated and some workmanship standards are included to discriminate between proper and improper work. Wave-soldering processes and surface mount technologies are specified in separate documents, and those processes require to be verified as prescribed in the respective standard. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 13291-2 Space product assurance —
Part 2: Quality assurance EN 13291-3 Space product assurance —
Part 3: Materials, mechanical parts and processes EN 13701 Space systems — Glossary of terms EN 14097 Space product assurance —
Non-conformance control system EN 100015-1 1992 Protection of electrostatic sensitive devices — Part 1: General requirements ECSS-Q-70-02 Space product assurance — Thermal vacuum outgassing test for the screening of space materials ECSS-Q-70-10 2) Space product assurance — Qualification printed circuit boards ECSS-Q-70-11 2) Space product assurance — Procurement of multilayer printed-circuit boards ECSS-Q-70-28 2) Space product assurance — Repair and modification of printed-circuit board assemblies ECSS-Q-70-38 2) Space product assurance — High-reliability soldering for surface-mount and mixed technology printed-circuit boards ECSS-Q-70-71 2) Space product assurance — Data for the selection of space materials ——————— 2) To be published. SIST EN 50390:2007

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EN 29453 (mod) Soft soldering fluxes – Chemical compositions and forms (ISO 9453) ISO EN 29454 Flux specification J-STD-004 Requirements for soldering fluxes 3 Terms, definitions and abbreviated terms 3.1 Terms and definitions For the purposes of this European Standard, the terms and definitions given in EN 13701 and the following apply. 3.1.1 base laminate see “substrate” 3.1.2 bifurcated (split) terminal terminal containing a slot or split in which wires or leads are placed before soldering 3.1.3 bit removable heat store of a soldering iron 3.1.4 blister delamination in a distinct local area or areas 3.1.5 bridging build-up of solder or conformal coating between parts, component leads or base substrate forming an elevated path (see “fillet”) 3.1.6 cable two or more insulated conductors, solid or stranded, of equal length, contained in a common covering; or two or more insulated conductors, of equal length, twisted or moulded together without common covering; or one insulated conductor with a metallic covering shield or outer conductor (shielded cable or coaxial cable) 3.1.7 chipped lead seal cracked glass-to-metal component package seal NOTE Often caused during lead forming operations. 3.1.8 cleanroom room in which the concentration of airborne particles is controlled, and which is constructed and used in a manner to minimize the introduction, generation, and retention of particles inside the room, and in which others parameters, e.g. temperature, humidity and pressure are controlled as necessary 3.1.9 clinched termination conductor or component lead which passes through a printed circuit board and is then bent to make contact with the printed circuit board pad SIST EN 50390:2007

3.1.10 cold solder joint joint in which the solder has a blocky, wrinkled or piled-up appearance and shows signs of improper flow or wetting action NOTE A cold solder joint can appear either shiny or dull, but not granular. It
normally has abrupt lines of demarcation rather than a smooth, continuing fillet between the solder and the surfaces being joined. These lines are caused by either insufficient application of heat or the failure of an area of the surfaces being joined to reach soldering temperature. 3.1.11 colophony see “resin” 3.1.12 component device which performs an electronic, electrical or electromechanical function and consists of one or more elements joined together and which cannot normally be disassembled without destruction NOTE The terms component and part may be interchanged. Typical examples of components are transistors, integrated circuits, hybrids and capacitors. 3.1.13 component lead solid wire which extends from and serves as a connection to a component 3.1.14 conduction soldering method of soldering which employs a soldering iron for transfer of heat to the soldering area 3.1.15 conductor lead or wire, solid or stranded, or printed circuit patch serving as an electrical interconnection between terminations 3.1.16 conformal coating thin protective coating which conforms to the configuration of the covered assembly 3.1.17 connection electrical termination 3.1.18 contact angle angle enclosed between half-planes, tangent to a liquid surface and a solid-liquid interface at their intersection NOTE In particular, the contact angle of liquid solder in contact with a solid metal surface. An approximate value for this can be determined by shadow projection or other means, by measuring after the solder has solidified. Note that the contact angle is always the angle inside the liquid. 3.1.19 contamination particles, liquids, gases, materials and micro-organisms which by their presence can disturb the performance of an item 3.1.20 cordwood construction circuitry in which components are mounted between, and perpendicular to, two printed circuit or conductive networks SIST EN 50390:2007

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3.1.21 corrosion deterioration of a metal by chemical or electrochemical reaction with its environment 3.1.22 cracked solder joint soldered connection which has fractured or broken within the solder 3.1.23 crazing condition existing in the base laminate of a printed circuit board in the form of connected white spots or “crosses” on or below the surface of the base laminate, reflecting the separation of fibres in the glass cloth and connecting weave intersections, usually related to mechanically induced stress 3.1.24 delamination distinct separation of printed circuit board layers (resin from glass) originating from or extending to the edges of a hole or edge of the board 3.1.25 dewetting condition in a soldered area in which the liquid solder has not adhered intimately, characterized by an abrupt boundary between solder and conductor, or solder and terminal or termination area (often seen as a dull surface with islands of thicker shiny solder) 3.1.26 discrete component any individually packaged electronic device, either active or passive (e.g. resistors, capacitors, inductors, diodes and transistors) 3.1.27 disturbed solder joint unsatisfactory connection resulting from relative motion between the conductor and termination during solidification of the solder 3.1.28 dross scum that forms on the surface of molten metal NOTE On liquid solder it can comprise impurity elements or oxidation products. 3.1.29 electrical connection conductive connection in electrical or electronic circuits 3.1.30 encapsulating compound electrically non-conductive compound used for environmental protection which completely encloses and fills in voids between electrical components 3.1.31 eutectic alloy alloy of two or more metals that has one distinct melting point NOTE One eutectic solder is a tin-lead alloy containing 63 % Sn and 37 % Pb which melts at 183 °C. 3.1.32 excessive solder joint unsatisfactory connection wherein the solder obscures the configuration of the connection, or prevents assessment of the true wetting angle SIST EN 50390:2007

3.1.33 eyelet tubular metal part inserted into a printed circuit board and having both ends headed or rolled over 3.1.34 fillet smooth concave build-up of material between two surfaces, e.g. a fillet of solder between a component lead and a solder pad or terminal, or a fillet of conformal coating material between a component and printed circuit board 3.1.35 flatpack (flat package) term used to describe the appearance of an integrated circuit which has been hermetically sealed within a thin, rectangular enclosure, with flat coplanar leads protruding from the periphery 3.1.36 flux material which, during soldering, removes the oxide film, protects the surface from oxidation, and enables the solder to wet the surfaces to be joined 3.1.37 flux activity property of a flux which allows the smallest contact angle between molten solder and a solid surface (see also “rosin”) 3.1.38 flux particle tiny fragment of flux residue of yellow or sometimes whitish translucent appearance NOTE Usually appears whitish green under ultraviolet light. 3.1.39 fractured joint soldered connection which has fractured or broken within the solder (see “cracked solder joint”) 3.1.40 glass meniscus glass fillet of a lead seal which occurs where an external lead leaves the package body 3.1.41 haloing condition existing in the base laminate of a printed circuit board in the form of a light area around holes or other machined areas on or below the surface of the laminate 3.1.42 hermetic seal seal which protects an enclosed circuit from corrosion by preventing the entry of such contaminants as water vapour 3.1.43 hook terminal terminal formed in a hook shape 3.1.44 hybrid microcircuit component performing an electronic circuit function which consists of a thick- or thin-film network on a substrate which supports active or passive chip components connected to it SIST EN 50390:2007

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3.1.45 icicles see “solder icicle” 3.1.46 integrated-circuit component individually packaged functional circuit formed by depositing an active or passive electronic element on to a substrate 3.1.47 interfacial connection conductor which connects conductive patterns between opposite sides of a printed circuit board (normally a plated-through hole or metallic wire) 3.1.48 lap joint joining or fusing of two overlapping metal surfaces with solder without use of any other mechanical attachment or support 3.1.49 measling/measles condition existing in the base laminate of printed circuit board in the form of discrete white spots or “crosses” below the surface of the base laminate, reflecting a separation of fibres in the glass cloth at the weave intersection NOTE During soldering this can be caused by excessive heat. 3.1.50 multi-layer circuit board product consisting of alternate laminates of printed circuit substrates and insulators, bonded together by simultaneous application of heat and pressure prior to drilling and plating holes for interconnections (see also “printed circuit board”) 3.1.51 overheated solder joint joint in which the solder can appear either shiny or dull, but which also has a crystalline appearance and shows evidence of a grain structure caused by excessive dwell time of a solder iron, too great a heat source, or repeated rework 3.1.52 pad termination of a conducting surface on a printed circuit board to which leads are soldered to form an electrical connection NOTE These can be described as either functional, where an active track is terminated, or non-functional, where the pad is isolated. 3.1.53 pin hole small hole in solder 3.1.54 pits small holes or sharp depressions in the surface of solder NOTE Pits can be caused by flux blow-out due to entrapment or overheating. SIST EN 50390:2007

3.1.55 plated-through hole hole formed by a deposition of metal on the inside surface of a hole NOTE Also known as a supported hole. The configuration is used to provide additional mechanical strength to the soldered termination or to provide an electrical interconnection on a double-sided or multi-layer printed circuit board. 3.1.56 porous solder joint joint with many pits having a grainy or gritty surface (due to overheating) 3.1.57 potting compound compound, usually electrically non-conductive, used to encapsulate or as a filler between components, conductors or assemblies 3.1.58 printed circuit board (PCB) product resulting from the process of selectively etching unwanted copper from one or both surfaces of a copper-clad insulating substrate to form a desired circuitry pattern which is subsequently solder- or gold-plated NOTE The term printed circuit board covers the following families: • single sided; • double sided, rigid or flexible; • multilayer, rigid or flex-rigid. 3.1.59 repair action taken on a nonconforming product so that it will fulfil the intended usage requirements although it will not conform to the originally specified requirements [ISO 8402:1994] NOTE
1 Repair is one type of disposition of a nonconforming product. NOTE
2 Repair includes remedial action taken to restore, for usage, a once conforming but now nonconforming product, for example, as part of maintenance. 3.1.60 resin natural substance that is usually transparent or translucent and yellowish to brown NOTE Resins are formed in plant secretions and are soluble in organic solvents, but not water. This is a generic term, rosin being the specific term with regard to soldering. 3.1.61 resistance soldering method of soldering by passing a current between two electrodes through the area to be soldered 3.1.62 rework action taken on a nonconforming product so that it will fulfil the specified requirements [ISO 8402:19
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