Page 13 - Wire Bonding in Microelectronics

xii Co n t e n t s

9.1.2 The Requirements for High-Yield
Bonding (Metallization Surface,
Hardness, Cleanliness) . . . . . . . . . . . . 295
9.1.3 The Bonding Machine and Its
Control . . . . . . . . . . . . . . . . . . . . . . . . . 299
9.1.4 Reliability for Small Numbers of
Bonds (Small Sample Statistics) . . . . 300
9.1.5 Package Related Bond-Yield Issues . . . 301
9.1.6 Possible Yield Problems and
Solutions . . . . . . . . . . . . . . . . . . . . . . . . 302
9.1.7 Other Considerations That May
Affect Overall Device Yield . . . . . . . . 304
9.1.8 Wire Looping . . . . . . . . . . . . . . . . . . . 305
9.1.9 Fine-Pitch Ball and Wedge Bonding . . . . 307
9.1.10 Reliability and Testing Problems of
Fine-Pitch Bonding . . . . . . . . . . . . . . . 310
Area Array Wire Bonding . . . . . . . . . 314
9.1.11 Conclusions of High Yield and
Fine Pitch . . . . . . . . . . . . . . . . . . . . . . . 315
9.2 Wire Bonding to PC boards, Flex, BGAs,
MCMs, SIPs, and Various Soft Substrate Devices
and High-Performance Systems . . . . . . . . . . . 315
9.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . 315
9.2.2 Bonding to Thin-Film Dielectric
Substrates . . . . . . . . . . . . . . . . . . . . . . . 316
9.2.3 Bonding to Laminate Substrates,
Such as PCBs, BGAs, SIPs, and
Buildup Layers . . . . . . . . . . . . . . . . . . 319
9.2.4. Buildup Layers . . . . . . . . . . . . . . . . . . 321
9.2.5 The Effect of a Polymer Substrate’s
Material Properties on Wire
Bonding . . . . . . . . . . . . . . . . . . . . . . . . 322
9.2.6 Additional Considerations When
Using Wire Bonds in Packages Running
at High Clock Rates in High-
Performance Systems (HPS) . . . . . . . 327
9.2.7 Skin-Effect in Typical Package/Board
Conductor Metal Structures . . . . . . . . . 327
9.2.8 Conclusions . . . . . . . . . . . . . . . . . . . 329
9.3 Wire Bonds in Extreme Temperatures/
Environments . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
9.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . 330
9.3.2. High Temperature Interconnection
Requirements . . . . . . . . . . . . . . . . . . . 330