FCBGA (Flip Chip Ball Grid Array)

Semiconductor devices used for backbone communication devices and high-end computers face increasing demands for higher speed and higher performance. In response to such demands, it is necessary to change to multiple pins for semiconductor devices, and offer excellent electrical characteristics: the answer therefore is the flip chip BGA.

The general method of electrically connecting the chips (bare chips) and substrate is the wire bonding method, in which the terminals are wired by thin gold wires while the chip circuit side is facing upward. However, in the flip chip BGA, the flip chip method is used for the electrical connection, in which the chips are connected to the substrate using soldering and a terminal bump, while the chip circuit side is facing downward. Compared with the wire bonding method, the flip chip method is distinguished by its support for high speed and high density, due to electrical characteristics made possible by the short wiring length. It can use several thousand pins, because the pins can be installed in a two-dimensional manner right underneath the chip, allowing it to easily accommodate demand for multiple pins. This arrangement also has a better heat relay capability because the heat can be released from the back of the chip due to its structure.

The challenge, however, is that production is difficult. By increasing the number of pins installed, the distance between pins is rapidly reduced. Thus, it becomes a test for technical personnel to find a way to connect the pins without affecting the adjacent pins. NEC Electronics is currently developing technology that will address this issue and contribute to lower package prices.