The solder is then re-melted to produce an electrical connection, typically using a thermosonic bonding or alternatively reflow solder process. To attach the flip chip into a circuit, the chip is inverted to bring the solder dots down onto connectors on the underlying electronics or circuit board. The chips are then cut out of the wafer as normal. A small dot of solder is then deposited on each metalized pad. This typically consists of several treatments. Near the end of the manufacturing process, the attachment pads are metalized to make them more receptive to solder. Processing a flip chip is similar to conventional IC fabrication, with a few additional steps. Side-view schematic of a typical flip chip mounting This is in contrast to wire bonding, in which the chip is mounted upright and fine wires are welded onto the chip pads and lead frame contacts to interconnect the chip pads to external circuitry. In order to mount the chip to external circuitry (e.g., a circuit board or another chip or wafer), it is flipped over so that its top side faces down, and aligned so that its pads align with matching pads on the external circuit, and then the solder is reflowed to complete the interconnect. The solder bumps are deposited on the chip pads on the top side of the wafer during the final wafer processing step. The technique was developed by General Electric's Light Military Electronics Dept., Utica, N.Y. Underside of a die from a flip chip packageДЇlip chip, also known as controlled collapse chip connection or its abbreviation, C4, is a method for interconnecting dies such as semiconductor devices, IC chips, integrated passive devices and microelectromechanical systems (MEMS), to external circuitry with solder bumps that have been deposited onto the chip pads.

What is flip 3d