Page 17 - Wire Bonding in Microelectronics

xvi Int ro duct ion to T h i r d E d it ion

This book is primarily concerned with understanding failures
and yield problems originating from chip-to-package wire bonds,
although other wire bonds, such as crossovers and PC board bonds,
are included as appropriate. Flip chip, TAB, lead-frame bonding, etc.,
are discussed briefly in Chap. 2 and are included elsewhere when
wire bond-type interfaces and failure mechanisms have been
observed. Newer pad metallurgies, such as Ni based (Chap. 6B)
are fully discussed, and the increasingly popular Cu wire bonding
(Chap. 3 and throughout) is described. Discussions of chip cleaning,
gold plating, and gold-aluminum intermetallics are still important.
The wirebonders themselves are not discussed in detail since they are
updated yearly and are usually proprietary, specialized autobonders,
and the manufacturers offer courses on their setup and use.
This book has been written to serve as a text to accompany courses
taught by the author and others, as well as a stand-alone book. The
color CD was introduced, since increasingly, modern figures are
difficult to understand without color. The book is written at a practical
level and is also intended for use by production line engineers in
solving, or avoiding, bonding problems. However, enough detail and
many references are included for failure analysis personnel or others
who are interested in doing design and research on the subject. Today
most published references are available for quick downloading from the
Internet (further explained in the Bibliography).
Areas where more research is needed are clearly indicated. It is
hoped that workers will study and fill in these gaps in the near future
rather than spend time adding extra decimal points to well-
characterized and understood problems. The author freely offers
opinions, which the reader is, of course, free to ignore!
This third edition has several invited authors who have contributed
special appendixes and chapters. This brings more diverse knowledge,
than the (main) author alone could contribute. These contribution-
authors are acknowledged, including their current (2009) addresses.
These new contributions are greatly appreciated and should increase
the areas of knowledge encompassed by this book!
It is assumed that all readers have a basic knowledge of wire
bonding, single or multiple device packaging, and/or hybrid/SIP
circuit assembly technology. Terms in general usage in these fields are
not defined in the text, but many are in the Glossary. The book is
divided into relatively independent chapters, and its Index can be
used to look up specific problems.
Manuscript organization. Each chapter of this book is self-contained
with its own references and numbering system. In some cases, this
results in the same reference appearing in two or more chapters. This
was thought to be the most convenient for readers. The chapters are
coupled together by referring in the text from one to another for
greater detail or explanation, where appropriate.