Quality Standard for Assembly

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Quality Standard for Assembly

Six Sigma for Electronics

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TOC

WIRING AND CABLING. 1
1.1 Wire, Electrical, Insulated. 1
1.1.1 Definitions... 1
1.1.2 General. 1
1.1.3 Stripping. 3
1.1.4 Routing. 4
1.1.5 Protection. 4
1.1.6 Terminating. 8
1.1.7 Splicing. 8 |
1.1.8 Cable Identification.. 8
1.2 Shielded Wire and Coaxial Cable. 8
1.2.1 Routing and Protection. 8
1.2.2 Termination. 9
1.3 Cabling. 9
1.3.1 Cable Tying and Lacing. 9
1.3.2 Cable Routing and Securing. 10
1.3.3 Cable Protection. 19 1.4 Bus Wire. 19
1.4.1 General. 20
1.4.2 Slack. 20
1.4.3 Clearance. 20
1.4.4 Insulation. 20
1.4.5 Rounded Edges on Tools. 20
1.5 Mechanical Connections for Soldering .. 20
1.5.1 Definition. 20
1.5.2 General Requirement. 21
1.5.3 Small Wire Sizes. 21
1.5. 4 Lug Without a Hole for Wire. 21
1. 5. 5 Terminal with a Hole for Wire. 21
1. 5. 6 Location and Direction of Wrap .. . 22
1. 5. 7 Contact of Wire with Terminal. 22
1. 5. 8 Contact of Threaded Wire. 22
1.5.9 Avoiding Tension on Solder. 23
1.5.10 Wire Heavier than Terminal .. 23
1.5.11 Close Terminal Spacing. 23
1. 5.12 Assembly of Lug to Wire. 23
1.5.13 Wire Inserted into Eyelet. 24
1.5.14 Wire to Component Lead Connection. 24
1.5.15 Component Leads Used as Terminals , .. 24
1.5.16 Wrapping on Adjacent Terminals. 25
1.5.17 Miniature Tube Socket Wiring. 25
1.5.18 Wrapping on a Slotted Terminal. 26
1.5.19 Cup-Type Terminals.. . 26 I 1.5.20 Control of Clippings.. 27
1.6 Hand Soldering. 27
1.6.1 Definition and Purpose. 27
1.6.2 Preparation... 28
1.6.3 Method. 28
1.6.4 Flux. 29
1.6.5 Choice of Solder. 30
1.6.6 Wetting Action. 30
1.6.7 Amount of Solder.. 30
1.6.8 Material Imbedded in Solder Joint .. 30
1.6.9 Wicking... 30
1.7 Solderless Crimp-Type Connections. 30
1.7.1 Approval for Use. 30
1.7.2 Tool and Method. 30
1.7.3 Tool Checking. 30
1.7.4 Wire Variation... 31
1.7.5 Fused Wire. 31
1.7.6 Solid Wire. 31
1.8 Sleeving. 31
1.8.1 Connector Terminals. 31
1.8.2 Pressure or Abrasive Action. 31
1.8.3 Grade and Fit.. . 31
1.8.4 Environmental Requirement. 31
1.8.5 Cable Covering. 31
1.8.6 Tolerance on Length. 31
1.9 Coils. 32
1.9.1 General. 32
1.9.2 Insulation., . 32
1.9.3 Broken Strands.. . 32
1.9.4 Slipped Turns . 32
1.9.5 Minimum Inside Diameter.. . 32
1.9.6 Coil Coating. 32
1.9.7 Voids in Potted Assembly. 32
1.9.8 Wiring and Soldering. 32
1.9.9 Similar Coils. 33
1.9.10 Securing of Coils, Leads and Terminals ....... 33
1.9.11 Resistor Notches for Coil Winding. 34
1.9.12 Damage. 34
1.9.13 Winding Direction . 34 1.10 Stray Material. 34
1.11 Connecting 3-Wire AC Cord. 34
II ELECTRICAL COMPONENTS ..... 37
2.1 Scope. 37 2.2 Storage, Handling, and Transportation. 37 2 .
2.1 Storage. 37
2.2.2 Damage and Contamination by Handling . .. 37
2.2.3 Damage in Transportation. 38
2.2.4 Bending of Component Leads for Storage. 38
2.3 Component Defects. 38
2.3.1 Damage to Insulation. 38
2.3.2 Illegible Component Markings. 38
2.3.3 Dents and Chips. 38
2.3.4 Cracks. 38
2.3.5 Improper Lead Tinning. 39
2.3.6 Lead Defects Reference. 39
2.3.7 Bent Leads.,. 39 I 2.3.8 Stray Material. 39
2.4 Component Lead Forming. 39
2.4.1 Changes in Ratings Due to Forming. 39
2.4.2 Readability of Markings. 39
2.4.3 Sharp Bends in Component Leads .. 39
2.4.4 Thermoplastic and Teflon Sleeving. 40
2.4.5 Positioning of Lead Bends. 40
2.5 Use of Tools for Wiring. 41
2.5.1 Tools for Lead Forming.. . 41
2.5.2 Tools with Sharp Edges. 41
2.5.3 Control of Clippings... 41
2.6 Component Positioning and Mounting .. 41
2.6.1 Positioning Within Boundaries .. 41
2.6.2 Neatness in Mounting. 42
2.6.3 Crossing of Component Leads. 43
2.6.4 Access to Mounting Holes and Controls ...... 43
2.6.5 Centering of Components. .. 43
2 .6.6 Strain Relief. 43
2.6.7 Component Support .. 44
2.6.8 Misuse of Components for Support. 44
2.6.9 Clearance from Sharp Edges. 44 2.6.10 Prevention of Clatter.. 44
2.6.11 Mounting of Heat Dissipating Components. 45
2.6.12 Mounting of Heat Sensitive Components. 45
2.6.13 Mounting of Components into Tubelets . ...... 46
2.6.14 Centering of Clip-Mounted Components. 46
2.6.15 Tightness of Mounting Clips. 46
2.6.16 Positioning of Stud-Mounted Components. 46
2.6.17 Mounting of Components Having Locating Tabs ... 46
2.6.18 Connections to Fuse Posts. 46
2.6.19 Twist-Tab Capacitors • *.. 46
III FASTENING. 47
3.1 Machine Screws. 47
3.1.1 Materials and Finishes. 48
3.1.2 Countersunk Screws (Flat and Oval Heads) . .... 48
3.1.3 Preferred Sizes and Class of Fit. 49
3.1.4 Minimum Thread Engagement and Thread Inserts. , 49
3.1.5 Thread Projection.*
3.1.6 Tightness...
3.1.7 ' Screwhead Imperfections.
3.1.8 Captive Screws.
3.2 Setscrews.
3.2.1 General.
3.2.2 Types of Drives...
3.2.3 Point Styles.. . . .
3.2.4 Locking . . ..
3. 3 Tapping Screws.
3.3.1 Materials and Finishes.
3.3.2 Types of Tapping Screws.
3.4 Nuts.. *
3.4.1 General...
3.4.2 Nonlocking Nuts .
3.4.3 Locking Nuts.
3.5 Rivets and Eyelets.
3.5.1 General.*
3.5.2 Rivet Types.
3.5.3 Material and Workmanship.
3.6 Washers.
3.6.1 Flat Washers.
3.6.2 Lock Washers.
3.6.3 Compressible Washers and Parts . . ..
3. 7 Miscellaneous Fastening and Locking Provisions.
3.7.1 Liquid Staking.
3.7.2 Solder Staking ...
3.7.3 Self-Locking Screws . .
3.7.4 Sheet Spring Nuts...
3.8 Adhesive Bonding.
3.8.1 Structural Adhesive Bonding..
3.8.2 Surface Preparation for Structural Bonding.
3.8.3 Adhesive Bonding, Elastomeric.
3.9 Stray Hardware.
MECHANICAL AND ELECTROMECHANICAL REQUIREMENTS . . .
4.1 General Requirements ...
4.1.1 Minimum Clearance of Moving Parts.• • *
4.1.2 Cracks, Chips, or Crazing Around Glass or Ceramic Seals, Insulators, Terminal Boards, and Connectors .
4.1.3 Burrs and Sharp Edges.-
4.1.4 Handling, Fitting, and Assembling ..........
4.2 Gears...
4.2.1 Definitions...*
4.2.2 Gear Alignment.
4.2.3 Gear Lubrication.
4.2.4 Gear Mesh.. . 73
4.2.5 Gear Loading . 73 4.3 Detents. 74
4.3.1 Detent Action. 74
4. 3. 2 Binding or Galling. 74
4.4 Bearings. 74
4.4 .1 General. 74
4.4.2 Ball Bearings. 76
4.4.3 Porous Self-Lubricating Bearings . 78
4. 4. 4 Plastic Sleeve Bearings. 79
4.5 Tuning Slug Racks . [ ] * 79
4. 5 .1 Alignment with Cam. 79
4.5 .2 Travel. 79
4.5.3 Slug Positioning. 79
4.5.4 Slug Stud Retainers. 79
4. 6 Switches and Relays.* 80
4. 6.1 General. 80
4.6.2 Switches . 81
4. 6 .3 Relays. 82
4.7 Retaining Rings. 83
4.7.1 Seating. 83
4.7.2 Installation. 83
4.7.3 Distortion. 83
4 .8 Pinned Assemblies. 83
4.8.1 Engagement With Hub.83
4.8.2 Protrusion from Hub. 83
4. 8 . 3 Tightness of Pins. 84
4.8.4 Distortion by Pinning. 84
4.9 Lubrication Requirements. 85
4. 9.1 General. 85
4.9.2 Absence of Requirements. ,. 85
4.9.3 Lubrication Instruction Plates. 85
4.9.4 Application, Quantity and Protection. 85
4.10 Appearance and Cleanliness. 85
4.10 .1 General Requirements . 85
4. 10.2 Cleanliness. 86
4. 10 .3 Special Areas of Appearance. 86
4 .11 Markings. 86
4.11.1 General._ 86
4 . 11.2 Decalcomanias (Decals) and Self-Adhesive Labels . . . 87
4.11.3 Ink Stamping. 87
4.11.4 Cable Marking Bands. 87
4.11.5 Tape Code Labels .. 87
4.11.6 Nameplates. 88
4.12 Latent Contamination. 88
V PRINTED CIRCUIT BOARD ASSEMBLY REQUIREMENTS. 89
5.1 Printed Circuit Board Specifications.
5.2 Eyelets, Tubelets, Terminals, and Plated-Thru Holes ... 89
5.2.1 Definitions. 99
5.2.2 Installation and Application. 90
5.2.3 Other Quality Requirements. 90
5.3 Component Attachment. 91
5.3.1 Components with Wire Leads. 92
5.3.2 Hardware Mounted Components. 92
5.3.3 "Snap-in" Components.. • 92
5.4 Quality Requirements for Printed Circuit Board Assemblies . 93
5.4.1 Component Bodies and Wire Leads. 93
5.4.2 Printed Circuitry Separation. 93
5.4.3 Base Laminate. 93
5.4.4 Repair of Printed Circuit. 94
5.5 Soldering on Printed Boards. 94
5.5.1 Preparation. 94 5.5.2 Fluxes. 94
5.5.3 Hand Soldering. 94
5.5.4 Dip-Soldering. 95
5.5.5 Removal of Flux Residues .. 95
5. 5. 6 Workmanship Standards - Dip-Soldered Boards. 95
5.6 Post-Coating. 96
5.6.1 Cleaning. 96
5.6.2 Masking. 96
5.6.3 Cured Coating Requirements. 96
5.7 Handling and Packaging. 96
APPENDIX A