TABLE OF CONTENTS After wafer sort, the chips on the wafer surface are completed and the electrically functioning ones identified. The chips will be incorporated into individual protective packages, mounted with other components in hybrid or multichip modules (MCMs), or connected directly onto a printed circuit board. This chapter describes the packages and processes used for chip protection and to connect the chip to electrical connections which, in turn, allow integration of the circuit into a larger electronic system.
Upon completion of this chapter, you should be able to:
List the four functions of a semiconductor package.
List the five common parts of a package.
Recognize and identify the major package designs.
List and describe the major packaging process flows.
After wafer sort, the chips are still part of the wafer. For use in a circuit or electronic product, they must be separated from the wafer and, in most cases, put in a protective package. They may also be mounted onto the surface of a ceramic substrate as part of a hybrid circuit, put into a large package with other chips as part of a multichip module (MCM), or be connected directly on board a printed circuit, chip-on-board, or direct chip attach (COB or DCA) (Fig. 18.1). All three options share some common processes. The packaging process, in addition to protecting the chip, provides an electrical connection system allowing the chip to be integrated into an electronic system, and it provides environmental protection and heat dissipation.
