Bath Lead-Free Soldering

1. Auflage 2007
ISBN: 978-0-387-68422-2
Verlag: Springer-Verlag
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 299 Seiten

The past few years have seen major developments in soldering materials and processes for electronics assembly manufacture due to the movement from tin-lead to lead-free soldering. The removal of lead from electronics solders due to environmental considerations first developed with proposed US legislation in the early 1990s. At that time, the alternatives had not been fully explored, so a ban on the use of lead in electronic solders was put on hold. However the seed was sown for development with various projects initiated during the 1990s in Europe, the Americas, and Asia. Based on government pressures, Japan OEMs began to move to lead-free solder products from 1998 and this, combined with the European Union ROHS (Restriction of Hazardous Substances) legislation enacted in 2006, drove the global manufacture of electronics consumer products with le- free solders. From 1998 to the present, the development of lead-free solder materials and processes has progressed to such an extent that development work moving forward will typically only concentrate on lead-free solders and components rather than tin-lead solders and components. This book aims to give the latest information on development of the lead-free soldering materials and processes and identify where more work is needed. The chapters of the book describe legislation, alloys, reflow, wave, rework, reliability, backward and forward process compatibility, PCB surface finishes and PCB laminates, and standards affecting the general lead-free soldering arena.

Autoren/Hrsg.

Bath, Jasbir

Inhaltsverzeichnis

1;Preface;5
2;Table of Contents;6
3;Chapter 1: Lead Restrictions and Other Regulatory Influences on the Electronics Industry;17
3.1;1.1 Introduction;17
3.2;1.2 A Regulatory Tour of Europe;18
3.3;1.3 A Regulatory Tour of Asia;26
3.4;1.4 A Regulatory Tour of the Americas;28
3.5;1.5 Business Impacts and Conclusions;29
3.6;Conclusions;30
4;Chapter 2: Fundamental Properties of Pb-Free Solder Alloys;32
4.1;2.1 Search for a Pb-Free Alternative to Sn-Pb Eutectic;32
4.2;2.2 Primary Alloy Design Criteria;32
4.3;2.3 Solder Alloy Solidification and Microstructural Development;36
4.4;2.4 Melting Behavior;36
4.5;2.5 Solidification Behavior;55
4.6;2.7 Pb-Free Solder Mechanical Behavior and Solder Joint Reliability;73
4.7;Future Work;80
4.8;Acknowledgements;81
4.9;References;81
5;Chapter 3: Lead-Free Surface Mount Assembly;86
5.1;3.1 Introduction;86
5.2;3.2 Solder Paste Alloy;86
5.3;3.3 Screen Printing Process;87
5.4;3.4 Component Placement;88
5.5;3.5 Reflow Soldering;89
5.6;3.6 Solder Joint Inspection and Acceptance Criteria;93
5.7;References;101
5.8;Summary;101
6;Chapter 4: Lead-Free Wave Soldering;102
6.1;4.1 Introduction;102
6.2;4.2 Lead-Free Wave Solder Alloy Alternatives;103
6.3;4.3 Wave Solder Equipment Recommendations;105
6.4;4.4 Process Recommendations;109
6.5;4.5 Solder Joint Characterization;113
6.6;4.6 Design Considerations;121
6.7;Conclusions;125
6.8;Acknowledgements;126
6.9;References;126
7;Chapter 5: Lead-Free Rework;128
7.1;5.1 Introduction;128
7.2;5.2 Lead-Free Hand Soldering SMT Rework;128
7.3;5.3 Lead-Free SMT Rework of BGA/CSP Soldered Joints;135
7.4;5.4 Lead-Free Pin-Through-Hole (PTH) Hand Solder Rework;146
7.5;5.5 Lead-Free Pin-Through-Hole Mini-Pot Rework Soldering;149
7.6;Acknowledgments;153
7.7;References;153
8;Chapter 6: Lead-Free Solder Joint Reliability;155
8.1;6.1 Introduction;155
8.2;6.2 General Trends;156
8.3;6.3 SAC Solder Joint Reliability Case Study;163
8.4;Conclusions;180
8.5;References;181
8.6;Acknowledgements;181
9;Chapter 7: Backward and Forward Compatibility;183
9.1;7.1 Introduction;183
9.2;7.2 Reliability of BGA/CSP Backward Compatibility;187
9.3;7.3 Estimation of Mixed Composition Liquidus Temperature;192
9.4;7.4 Chip Component and Lead- Frame Component Backward Compatibility;197
9.5;7.5 Forward Compatibility;200
9.6;7.6 Press Fit Connector Interconnections;202
9.7;Summary;203
9.8;Acknowledgements;204
9.9;References;204
10;Chapter 8: PCB Laminates;208
10.1;8.1 Introduction;208
10.2;8.2 Types of Stress in Printed Wiring Boards;209
10.3;8.3 Laminate Material Test Methods;211
10.4;8.4 Accelerated Thermal Stress Testing;215
10.5;8.5 Accelerated Thermal Stress Test Methods;218
10.6;8.6 HATS Test Method – A Case Study;221
10.7;Conclusions;227
10.8;References;228
10.9;Future Work;228
10.10;Acknowledgements;228
11;Chapter 9: Lead-Free Board Surface Finishes;230
11.1;9.1 Introduction;230
11.2;9.2 Process Overview;231
11.3;Summary;270
11.4;Acknowledgements;276
11.5;References;276
12;Chapter 10: Lead-Free Soldering Standards;279
12.1;10.1 Introduction;279
12.2;10.2 IPC and JEDEC Standards;279
12.3;10.3 IEC Standards;287
12.4;10.4 Japan (JEITA) Standards;288
12.5;10.5 Other Standards;289
12.6;Conclusions;289
12.7;References;290
12.8;Future Work;290
13;Conclusions;293
14;Index;299