Page 6 - Wire Bonding in Microelectronics

Contents

Introduction to Third Edition . . . . . . . . . . . . . . . . . . xv
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . xviii
Introduction to CD . . . . . . . . . . . . . . . . . . . . . . . . . . . xix
1 The Technical Introduction to the
Third Edition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 The Wedge- and Ball-Bonding Machine
Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 How to Approach Bonding Problems? . . . . . . 6
1.2.1 Which Metals Can Be Ultrasonically
Bonded? . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2.2 Assessing the Bondability and
Reliability of Proposed New Bond
Systems . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.2.3 Some Unusual Uses of Wire Bonds . . . 10
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2 Ultrasonic Bonding Systems and Technologies,
Including a Description of the Ultrasonic
Wire Bonding Mechanism . . . . . . . . . . . . . . . . . . . . 13
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2 Ultrasonic Transducer and Tool
Vibration Modes . . . . . . . . . . . . . . . . . . . . . . . . 14
2.3 How Ultrasonic Bonds Are Made
(Empirical Description) . . . . . . . . . . . . . . . . . . 22
2.3.1. Brief Phenomenological Explanation
of the Ultrasonic and Thermosonic
Bonding Process . . . . . . . . . . . . . . . . 24
2.4 Bonding with High(er) Frequency
Ultrasonic Energy . . . . . . . . . . . . . . . . . . . . . . . 30
2.5 In-Process (Real-Time) Bond Monitoring . . . . 32
2.6 Wire-Bonding Technologies . . . . . . . . . . . . . . . 33
2.6.1 Thermocompression Bonding . . . . . . 33
2.6.2 Ultrasonic Wedge Bonding
(Small- and Large-Diameter Wires) . . . 34
2.6.3 Thermosonic Ball and
Wedge Bonding . . . . . . . . . . . . . . . . . . 36
2.6.4 Choosing a New/Different
Wire-Bonding Technology . . . . . . . . . 36

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