Flip chip

This article is about the semiconductor mounting technique. For the DEC PDP module, see Flip Chip (PDP module). For the CPU format, see Flip-chip pin grid array.
Intel Mobile Celeron in a flip-chip BGA package (FCBGA-479); the flip chip, BGA substrate is dark yellow, and the silicon die appears dark blue
Underside of a die from a flip chip package, the top metal layer on the IC die or top metallization layer, and metallized pads for flip chip mounting are visible

Flip chip, also known as controlled collapse chip connection or its abbreviation, C4,[1] 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. The technique was developed by General Electric's Light Military Electronics Department, Utica, New York.[2] The solder bumps are deposited on the chip pads on the top side of the wafer during the final wafer processing step. 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. 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.[3]

  1. ^ E. J. Rymaszewski, J. L. Walsh, and G. W. Leehan, "Semiconductor Logic Technology in IBM", IBM Journal of Research and Development, 25, no. 5 (September 1981): 605.
  2. ^ Filter Center, Aviation Week & Space Technology, September 23, 1963, v. 79, no. 13, p. 96.
  3. ^ Peter Elenius and Lee Levine, Chip Scale Review. "Comparing Flip-Chip and Wire-Bond Interconnection Technologies". July/August 2000. Retrieved July 30, 2015.