A flip chip is one type of mounting used for
semiconductor devices, such as
IC chips, which does not require any wire bonds. Instead the final
wafer processing step deposits
solder bumps on the chip pads, which are used to connect directly to the associated external circuitry. This mounting is also known as the Controlled Collapse Chip Connection, or C4.
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another name for a bumped die. Bumped die are flipped over to solder them down, hence the name flip chip.