Page 333 - A Practical Guide from Design Planning to Manufacturing

Chapter
10

Microprocessor Packaging

Overview
This chapter discusses how completed die are packaged for use. The chapter
describes the trade-offs of different types of packages and presents an
example package assembly flow.

Objectives
Upon completion of this chapter the reader will be able to:

1. Visualize how multiple levels of packaging are used in an electronic
system.
2. Describe common package lead configurations.
3. Compare and contrast wire-bond and flip-chip packages.
4. Describe different types of package substrates.
5. Be aware of the trade-offs of important package design choices.
6. Understand thermal resistance and the factors that affect it.
7. Describe the trade-offs of using a multichip package.
8. Explain a typical package assembly process.

Introduction
The microscopic size of the features in integrated circuits makes a single
chip the size of a thumbnail capable of enormous computational per-
formance. This tiny size also means the same chip is damaged very easily.
Most chips would be thoroughly ruined by simply picking them up. Any
surface structure would be obliterated and even if coated in insulation,

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