Assembly and Joining Handbook - IPC

1 IPC-AJ-820 AAssembly and JoiningHandbookDeveloped by the Assembly and Joining Subcommittee (7-35) of theProduct Assurance Committee (7-30) of IPCU sers of this publication are encouraged to participate in thedevelopment of future :IPC3000 Lakeside Drive, Suite 309 SBannockburn, Illinois60015-1249 Tel 847 847 :IPC-AJ-820 - April 1997 Table of Assembly and Joining Technology .. Through-Hole Technology .. Surface Mount Technology .. Related Documents .. Joint Industry Standards .. IPC - Association Connecting ElectronicsIndustries Documents .. United States Government Documents .. American Society of Mechanical Engineers .. ASTM International .. SAE International .. Federal Aviation Regulations (FARs) .. Underwriters Laboratories .. IEC Standards .. Independent Distributors of ElectronicsAssociation (IDEA).

2 Electrostatic Discharge Association .. 132 HANDLING ELECTRONIC Definitions .. Electrostatic Discharge (ESD) .. Electrostatic Discharge SensitiveComponents (ESDS) .. Electrical Overstress (EOS) .. Handling of ESDS Items (Componentsand/or Assemblies) .. Electrical Overstress (EOS) DamagePrevention .. Electrostatic Discharge (ESD) DamagePrevention .. Physical Handling .. Handling after Soldering .. Contamination .. Processing Moisture Sensitive Components .. Classification of Non-IC ElectronicComponents for Assembly Processes(ECA/IPC/JEDEC J-STD-075) .. 163 DESIGN Background and Theory .. Basic Considerations .. End-Product Usage .. and Reliability .. for Producibility .. Packaged-Component AssemblyConsiderations .. Component Orientation .. Accessibility .. Design Envelope.

3 Clearances .. Physical Support .. Design for Automated Assembly .. Fiducial Marks .. Automated Through Hole Assembly .. Automated Surface Mount Assembly .. Automated Mixed-Technology Assembly .. Through Hole Assembly .. Lead Configuration .. Lead/Hole Relationships .. Through Hole Land Patterns .. Surface Mount Assembly .. Basic Printed Board Features .. Manufacturing Allowances .. SMT Land Pattern Details .. SMT Assembly Processing .. 304 PRINTED CIRCUIT General Considerations .. Design Issues .. Structures .. Leaded vs. Leadless Components .. CTE Issues .. PCB Materials .. Thermosetting Base Resins .. Printed Boards with Non-MetallicConstraining Cores .. Base Conductors .. Metallic Foils .. Electrodeposited Copper Foil .. Rolled-Annealed Copper Foil.

4 Additive Circuit Plating .. and Surface Finishes .. Copper Plating .. Coatings .. Copper Plating .. Plating .. Silver .. Tin .. Solderability Preservative (OSP) .. Plating .. 43 February Plating .. Coating .. Other Metallic Coatings for Edge PrintedBoard Contacts .. Printed Board Handling and StorageGuidelines .. 455 ELECTRONIC CIRCUIT Finishes .. Sensitivity .. versus Passive Components .. versus Integrated Components .. Through Hole versus Surface MountComponents .. Hole Lead Components .. Mount - Leadless Components .. Mount - Leaded Components .. Assemblies .. of Component .. Circuit Board Connectors .. Circuit Board Connector Selection .. Points and Test Jacks .. Design and Assembly ProcessImplementation for BGAs (IPC-7095) .. Design and Assembly ProcessImplementation for Bottom TerminationComponents (BTC) (IPC-7093).

5 Design and Assembly ProcessImplementation for Flip Chips (IPC-7094) .. Counterfeit Electronic Components and/orCounterfeit Mechanical Fasteners .. Mechanical Fasteners .. Electronic Components .. Solderability .. Finishes .. Surface Finishes .. Finishes .. Finishes .. Underplate .. of Solderability .. Conditioning .. Printed Wiring Board Weak KneePhenomena .. Troubleshooting a Solderability Problem .. Solderability Tests .. IPC J-STD-002 .. Force Measurement .. IPC J-STD-003 .. The Importance of Flux Material inSolderability Testing .. 607 Assembly AND Joining Introduction .. Presoldering Chemicals .. Metal Surface Activating Solutions .. Solder Mask .. Protective Coatings .. Solder Fluxes .. Choosing the Proper Flux .. Types .. Rosin/Resin Fluxes (RO or REClassification).

6 No Clean Fluxes .. Fluxes (OR Classification) .. Fluxes (IN Classification) .. Oils .. Alloy Selection .. and Application .. Specifications .. Temperature Solder Alloys .. and Techniques .. Soldering .. Considerations .. Solder Alloys .. Temperature Soldering Flux .. Temperature Stripping and Tinning .. Solder Alloys .. Paste .. Paste Alloys .. Test Methods to Evaluate SolderPaste Properties .. Paste Application .. Preforms .. Preform Alloys .. Solder Preforms .. 90 IPC-AJ-820 AFebruary Heating .. Materials .. Epoxy Adhesives .. Silicone Adhesives .. Polyurethane .. Acrylic Adhesives .. Cyanoacrylates .. Electrically Conductive Adhesives .. Surface Mount Adhesives .. Thermally Conductive Adhesives .. Verification .. Verification .. Whiskers .. Summary .. General Guidelines for Migrating toRoHS Compliant Finishes.

7 Electronic Component Lead andTerminal Finishes .. Connectors .. Bars .. Sinks .. Circuit Boards (PCB) .. How Can I Tell If A ComponentContains A Tin-Finish? .. Testing to Detect the Presence ofVarious Metals that may, or maynot be Present in a Component Lead/Termination Finish .. Dispersive Spectroscopy .. 1048 COMPONENT Classifications .. Levels .. Circuit Board Assembly Types .. Guidelines .. Options and Considerations .. Considerations .. Mounting Structure Materialsand Considerations .. Sinks .. Spreaders .. Conductive Insulators .. Design Cycle .. Guidelines .. Formats and ProcessSequences .. Assembly .. Characteristics,Through-Hole .. Discrete Components .. Discrete Components .. Packages .. Packages .. Components .. Grid Arrays .. Connectors .. Sockets .. Sequence, Through-Hole.

8 Steps .. Placement .. Mounting .. Technology .. Techniques .. Techniques .. Masking Guidelines .. Mount .. Hierarchy .. Assembly Techniques .. Assembly Techniques .. Process of Wetting .. and Solderability .. Alloys .. of the Solder Bond .. Growth Rates .. Affecting Physical Propertiesof Solder Alloys .. Rate Effects .. Grain Size Effects .. Soldering: ProcessConsiderations: .. Removal .. for Gold Removal .. Purity .. for Testing .. Frequency .. 158 February .. Arsenic .. Bismuth .. Silver .. Nickel .. Solder Pot Contamination .. Effect of Contamination on SolderProcess .. Resolving Contamination Problems .. Depletion .. Processes .. Soldering .. Application .. Application .. Soldering .. Transfer Considerations .. Control - ThermalConsiderations for Componentsand Boards.

9 Heat Sinks .. Selection .. Tip Materials .. Soldering Iron Tip Selection .. Shape/Physical Configuration .. Tip Maintenance .. Soldering Iron Station Maintenance .. Extending Tip Life .. Soldering-Soldering Toolsand Equipment .. Soldering .. Flared Flange Hardware .. Shank Discontinuities .. Flared Flange Angles .. Terminal Mounting .. General Requirements .. To Terminals .. Turret and Hook Terminals .. Bifurcated, Pierced or PerforatedTerminals .. Cup and Hollow CylindricalTerminal Soldering .. Holes .. Holes (PTH) .. Fill of Hole .. Mounted Components -Solder Conditions .. in Lead Bend .. Meniscus in Solder .. Interfacial Connection WithoutLead - Vias .. Obstruction .. Soldering .. Soldering .. Controls .. Fluxing .. Fluxing .. Fluxing .. Fluxing.

10 Solder Wave .. Wave .. Wide Wave .. (Supported) Wave .. Provisions .. Board Conveyors .. Conveyors .. Conveyors .. Conveyors .. Control .. Atmospheres .. Fluids .. Considerations .. Considerations .. Control .. Dross Reclamation and Recovery .. Solder Pots .. Soldering .. Process Elements .. Expectations .. Optimization and Control .. Soldering .. Test Assembly .. of Thermocouples .. Profile .. Down of Surface Mount Leads .. Reflow Soldering Methods .. 183 IPC-AJ-820 AFebruary Hot Bar Reflow Soldering-Resistance Hot Bar /Pulse soldering .. Laser Reflow Soldering .. Vapor Phase Soldering .. IR Soldering .. The IR Reflow Process .. MVC Temperature Determination .. Air/Atmosphere Quality .. Monitoring and Control .. Profiling Devices .. Temperature Control.