• BS 6221-23:1991

    Withdrawn A Withdrawn Standard is one, which is removed from sale, and its unique number can no longer be used. The Standard can be withdrawn and not replaced, or it can be withdrawn and replaced by a Standard with a different number.

    Printed wiring boards Guide for the design and use of printed wiring boards: surface mounted devices

    Available format(s):  Hardcopy, PDF

    Withdrawn date:  01-03-2007

    Language(s):  English

    Published date:  28-02-1991

    Publisher:  British Standards Institution

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    Table of Contents - (Show below) - (Hide below)

    Committees responsible
    Foreword
    Guide
    1. Scope
    2. Definitions
    3. Design for surface mounting components
    3.1 General
    3.2 Design considerations
    4. Substrates and mounting of chip carriers
    4.1 Introduction
    4.2 Resin and fabric substrates
    4.4 Leadless ceramic chip carriers (LCCCs)
         considerations
    4.5 Plastic leaded chip carriers (PLCCs)
    4.6 Mounting considerations
    5. Soldering process considerations
    5.1 Introduction
    5.2 Designing for soldering
    5.3 Wave soldering
    5.4 The infra-red (IR) reflow soldering process
    5.5 The condensation reflow soldering process (vapour
         phase)
    5.6 Onsertion machine to pattern alignment
    5.7 Artwork
    5.8 Solder resist
    5.9 Solder paste
    5.10 Design for adhesive application
    5.11 Process and assembly parameters
    5.12 Conductor geometries
    5.13 Guidelines for wave-soldered layout
    5.14 Guidelines for reflow-soldered layout
    5.15 Metallic finishes
    5.16 Solder resistive coatings
    6. Land design for SMDs
    6.1 Two terminal SMD
    6.2 Land dimension calculations
    6.3 Multiple terminal SMDs
    6.4 Solder mask considerations
    6.5 Additional considerations
    7. Recommended component layouts
    7.1 Component separation
    7.2 Auto placement clearances (ACPs)
    7.3 Mixed components
    8. Testability of surface mounted assemblies (SMAs)
    8.1 Introduction
    8.2 Fixturing. General information for designers
    8.3 Test probes
    8.4 Design consideration
    8.5 Recommended code of practice
    8.6 Methods for providing open nodes
    8.7 Recommendations for vacuum fixturing on a 2.54 mm
         (0.100 in) pitch
    Tables
    1. Mounting of ceramic devices
    2. Process and assembly parameters
    3. Physical dimensions of rectangular chip components
    Figures
    1. Possible board configurations
    2. Wave soldering
    3. Design for adhesive application
    4. Orientation of component to solder wave direction
    5. Layout and terminology for chip component lands
    6. The effect of component rotation
    7. Rectangular chip components dimensions and
         terminology
    8. Recommended design land pattern parameters for
         surface mounted assembly 1206 resistor
    9. Recommended design land pattern parameters for
         surface mounted assembly capacitors
    10. Recommended design land pattern parameters for
         surface mounted assembly SO-123
    11. Recommended design land pattern parameters for
         surface mounted assembly SO-197
    12. Recommended deisng land pattern parameters for
         surface mounted assembly SO1C (SO-193A, SO-193B,
         SO-193C)
    13. Recommended design land pattern parameters for
         surface mounted assembly SO1C (SO-192A, SO-192B,
         SO-192C, SO-192D)
    14. Recommended design land pattern parameters for
         surface mounted assembly SO-200
    15. Recommended design footprint parameters for surface
         mounted assembly plastic 'J' leaded chip carriers
    16. Recommended design footprint parameters for surface
         mounted assembly leadless chip carriers (square)
    17. Recommended design footprint parameters for surface
         mounted assembly leadless chip carriers
         (rectangular)
    18. Recommended design footprint parameters for surface
         mounted assembly tantalum chip capacitors
    19. Recommended design footprint parameters for surface
         mounted assembly tantalum rectangular chip
         capacitors
    20. Preferred distance between chip components
    21. Chip components: clearance dimensions for ACP
    22. Traditional fixtures with protective carriage plate
    23. SMA fixture without protective carriage plate
    24. Test probes and modules
    25. Module test probe access to a matrix of SMDs
    26. Test lands for surface mounted components
    27. Provision of test lands

    Abstract - (Show below) - (Hide below)

    Gives guidance on the design of printed wiring boards for surface mounted components. Addresses substrates and mounting of surface mounting device carriers, soldering process, land design, component layouts, and testability. Contains several figures.

    General Product Information - (Show below) - (Hide below)

    Committee EPL/501
    Development Note Supersedes BS 6221(1982) (07/2004)
    Document Type Standard
    Publisher British Standards Institution
    Status Withdrawn
    Superseded By
    Supersedes

    Standards Referencing This Book - (Show below) - (Hide below)

    BS 6221-20:1984 Printed wiring boards Guide for the assembly of printed wiring boards
    BS 6221-3:1984 Printed wiring boards Guide for the design and use of printed wiring boards
    BS 6221-21:1984 Printed wiring boards Guide for the repair of printed wiring boards
    BS 9075 N001:1981 Detail specification for fixed ceramic dielectric capacitors (type 1 and type 2). Rectangular monolithic chip. Full assessment level
    BS 6221-2:1982 Printed wiring boards Methods of test
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