IC Component Sockets / Edition 1

by Weifeng Liu, Michael Pecht

Overview

A broad and practical reference to IC socket technology

The first and only comprehensive resource on IC (Integrated Circuit) socket technology, IC Component Sockets offers a complete overview of socket technology and design in order to provide engineers and their managers with a good understanding of these specialized technologies and the processes for evaluating them. The authors, both acknowledged experts in the field, address all relevant aspects of the subject-including materials, design, performance characteristics, failure modes and mechanisms, and qualification and reliability assessment-with emphasis on the technology's inherent advantages and challenges.

Topics of interest include:
* Socket design and contact technologies
* Performance characteristics and material properties
* Contact failure modes and mechanisms
* Qualification testing conditions
* Qualification sequences and setup
* IEEE prediction methodology
* Theoretical calculation of contact reliability


Including a list of standards and specifications, this book is an important and timely resource for today's electronics engineers concerned with evaluating and perfecting socket design, manufacture, and use.

Product Details

ISBN-13:	9780471460503
Publisher:	Wiley
Publication date:	03/25/2004
Pages:	232
Product dimensions:	6.35(w) x 9.55(h) x 0.60(d)

About the Author

WEIFENG LIU, PHD, is an Interconnect Specialist at the Business Critical Systems Organization of Hewlett Packard Company. A member of IMAPS and IEEE, he has published numerous papers and has one patent pending.

MICHAEL PECHT, PHD, is a professional engineer and a Fellow of IEEE and ASME. He is the founder and director of the CALCE Electronic Products and Systems Center at the University of Maryland. Among the awards he has received are the 3M Research Award, the IEEE Undergraduate Teaching Award, and the IMAPS William D. Ashman Memorial Achievement Award for his contributions in the field. He has written sixteen books on electronic product development, served as chief editor of the IEEE Transactions on Reliability, and served on the Advisory Board of IEEE Spectrum.

Table of Contents

Preface xi

1 IC Component Socket Overview 1

1.1 Levels of Interconnections 1

1.2 Component-to-Board Interconnection 2

1.3 Classification of Component Sockets 3

1.4 Structure of IC Component Sockets 4

1.4.1 Socket Housing 5

1.4.2 Socket Contact 8

1.4.3 Socket Actuation 8

1.4.4 Heat Sink 9

1.4.5 Socket Polarization 10

1.5 Socket Function 10

1.6 Socket Assembly 11

1.7 Benefits of Using IC Component Sockets 11

1.7.1 Component Test and Burn-in 11

1.7.2 Component Upgrade and Exchange 12

1.7.3 Flexibility in IC Design and Assembly and Supply Chain Management 13

1.7.4 Use of Sockets to Avoid Soldering 13

1.7.5 Component Replacement and Repair 14

1.7.6 Cost Savings 14

1.8 Challenges Facing IC Component Sockets 15

1.8.1 Extra Signal Path 15

1.8.2 Increased Assembly Area 15

1.8.3 Compatibility with Fine-Pitch Applications 15

1.8.4 Reliability 16

1.9 IC Component Socket Market 17

1.10 Summary and Future Directions 18

References 18

2 Component Socket Properties 21

2.1 Socket Contact 21

2.1.1 Insertion and Extraction Force 21

2.1.2 Contact Retention 24

2.1.3 Contact Force and Resistance 25

2.1.4 Contact Deflection and Resistance 27

2.1.5 Contact Wipe 29

2.1.6 Current Rating 31

2.1.7 Capacitance and Inductance 32

2.1.8 Bandpass and Bandwidth 35

2.2 Socket Housing 37

2.2.1 Electrical Properties 37

2.2.2 Mechanical Properties 39

2.2.3 Temperature Rating 41

2.2.4 Flammability 42

2.3 Summary 43

References 43

3 IC Component Socket Materials 45

3.1 Socket Housing 45

3.1.1 Polymer Fundamentals 45

3.1.2 Thermoplastics 47

3.1.3 Thermosetting Polymers 50

3.1.4 Additives 52

3.1.5 Housing Manufacturing 53

3.2 Socket Contact 53

3.2.1 Copper Alloys 54

3.2.2 Nickel Alloys 59

3.2.3 Conductive Elastomers 60

3.2.4 Contact Manufacturing 61

3.3 Socket Contact Plating 64

3.3.1 Noble Metal Plating 65

3.3.2 Non-Noble Metal Plating 69

3.3.3 Underplate 70

3.3.4 Plating Process 71

3.4 Summary 74

References 74

4 Component Sockets for PTH Packages 76

4.1 DIP Sockets 76

4.1.1 DIP Socket Designs 76

4.1.2 Dual-Beam Contact Design 78

4.1.3 Single-Beam Contact Design 79

4.1.4 Multiple-Finger Contact Design 80

4.1.5 Low-Force Contact Design 81

4.1.6 ZIF Contact Design 81

4.1.7 Insertion and Extraction Tools 81

4.2 PGA Sockets 82

4.2.1 PGA Socket Designs 82

4.2.2 Dual-Beam Contact Design 85

4.2.3 Multiple-Finger Contact Design 85

4.2.4 Fuzz Button Contact Design 85

4.2.5 ZIF Contact Design 86

4.2.6 Insertion and Extraction Tools 86

4.3 Summary 87

References 87

5 Component Sockets for J-Leaded Packages 88

5.1 Socket Designs 88

5.1.1 Single-Pinch Contact Design 89

5.1.2 Dual-Pinch Contact Design 90

5.1.3 Side-Contact Design 90

5.1.4 Nested-Contact Design 90

5.1.5 ZIF Contact Design 91

5.1.6 Insertion and Extraction Tools 91

5.2 Summary 92

References 93

6 Component Sockets for Gull-wing Packages 94

6.1 Socket Designs 94

6.1.1 Shoulder Contact Design 94

6.1.2 Tip Contact Design 95

6.1.3 Foot Contact Design 96

6.1.4 Ankle Contact Design 97

6.1.5 Dual-Pinch Contact Design 98

6.1.6 Insertion and Extraction Tools 98

6.2 Summary 99

References 99

7 Component Sockets for BGA Packages 100

7.1 Socket Designs 100

7.1.1 Solder Ball Bottom Contact Design 102

7.1.2 Single-Sided Contact Design 105

7.1.3 Double-Sided Contact Design 106

7.1.4 Four-Point Crown Contact Design 108

7.2 Summary 109

References 109

8 Component Sockets for LGA Packages 110

8.1 LGA Socket Designs 112

8.1.1 Metallic Spring Design 114

8.1.2 Pogo Pin Socket Design 123

8.1.3 Wire-Button Contact Design 125

8.1.4 Conductive Elastomer Design 125

8.2 Comparison of Contact Reliability 134

8.3 Future Challenges for LGA Socket Design 135

8.4 Summary 135

References 136

9 Failure Modes and Mechanisms 138

9.1 Dry Oxidation 140

9.2 Pore Corrosion 141

9.3 Creep Corrosion 142

9.4 Fretting Corrosion 143

9.5 Galvanic Corrosion 145

9.6 Stress Corrosion 145

9.7 Electrochemical Migration 145

9.8 Intermetallic Formation 145

9.9 Stress Relaxation 146

9.10 Creep 147

9.11 Fracture and Fatigue 148

9.12 Friction Polymerization 148

9.13 Whisker Growth 149

9.14 Fungus Growth 150

9.15 Contact Wear 151

9.16 Outgassing 152

9.17 Leakage Current and Dielectric Breakdown 152

9.18 Swelling 153

9.19 Summary 153

References 154

10 Socket Testing and Qualification 158

10.1 Accelerated Testing 158

10.2 Environmental Classifications 161

10.3 Test Conditions 162

10.3.1 Preconditioning 162

10.3.2 Shock and Vibration 162

10.3.3 Thermal Aging 164

10.3.4 Temperature Cycling 164

10.3.5 Thermal Cycling with Humidity 165

10.3.6 Mixed Flowing Gas Tests 165

10.3.7 Particulate Tests 168

10.4 Test Sequencing 170

10.5 Four-Wire versus Two-Wire Measurement 170

10.6 Periodic and Continuous Monitoring 171

10.7 Virtual Reliability Assessment 172

10.8 Socket Qualification 173

10.9 Summary 174

References 174

11 Reliability Assessment 176

11.1 Contact Resistance Theory 176

11.2 Contact Reliability Theory 179

11.3 Intermittences 182

11.4 Socket Reliability Prediction 183

11.4.1 IEEE Reliability Prediction Standard 1413 183

11.4.2 Guidebook for IEEE Standard 1413 185

11.5 Achieving Socket Reliability 185

11.6 Summary 190

References 190

12 Standards and Specifications 192

12.1 Standards and Specifications 192

12.2 Obtaining Documents 199

Appendix A Terms and Definitions 201

Appendix B Socket Manufacturers 206

Index 215

What People are Saying About This

From the Publisher

"…thoroughly examines the arena of IC component sockets…it is highly recommended…" (E-STREAMS, May 2005)

Editorial Reviews

"…thoroughly examines the arena of IC component sockets…it is highly recommended…" (E-STREAMS, May 2005)

From the Publisher