Lead-Free Soldering (eBook)

Jasbir Bath (Herausgeber)

eBook Download: PDF

2007 | 2007
XIV, 299 Seiten
Springer US (Verlag)
978-0-387-68422-2 (ISBN)

Infos

The worldwide trend toward lead-free components and soldering is especially urgent in the European Union with the implementation strict new standards in July 2006, and with pending implementation of laws in China and California. This book provides a standard reference guide for engineers who must meet the new regulations, including a broad collection of techniques for lead-free soldering design and manufacture, which up to now have been scattered in difficult-to-find scholarly sources.

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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.

Inhalt

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

Produkt-Details

• Erscheint lt. Verlag: 26.6.2007
• Zusatzinfo: XIV, 299 p.
• Verlagsort: New York
• Sprache: englisch
• Themenwelt: Recht / Steuern ► EU / Internationales Recht
• Themenwelt: Recht / Steuern ► Öffentliches Recht ► Umweltrecht
• Themenwelt: Technik ► Elektrotechnik / Energietechnik
• Themenwelt: Technik ► Maschinenbau
• Schlagworte: Electronics • Process Engineering • Quality assurance • Reliability • Standard
• ISBN-10: 0-387-68422-0 / 0387684220
• ISBN-13: 978-0-387-68422-2 / 9780387684222