ABSTRACT
Figure 1 is a cross section of a module used in an IBM server and illustrates the wide variety of materials that are used by the semiconductor industry. At the top is the semiconductor chip, which may contain tens of thousands of discrete transistors interconnected
by submicrometer-wide metal lines, and in turn is connected to a ceramic carrier by an array of solder bumps. The solder bumps act as conduits for power and signal transmission. The ceramic carrier itself has layers of wiring buried within its structure. This arrangement permits multiple chips to be mounted on a single carrier. On the opposite side of the ceramic carrier an array of pins is attached that provides the input/output (I/O) and power connections to the computer's main circuit board.
