Definition: hybrid bonding

A variety of semiconductor packaging methods that join chips or wafers together to save space. Wafer-to-wafer (W2W) bonds two wafers together before being cut into chips. Die-to-wafer (D2W) bonds chips onto the wafer, and die-to-die (D2D) bonds chips on top of chips.

Hybrid bonding is used with GPUs and AI processors, CPUs, 3D flash memory, high bandwidth memory (HBM) and image sensors. The most complex chip manufacturing to date, it requires state-of-the-art equipment in particle-free environments, and it is costly and complicated. Surfaces must be polished to absolute flatness, and a microscopic speck of dust or a height variance of only a couple nanometers causes the assembly to fail.

Get Rid of These Solder Bumps

Hybrid bonding eliminates the vertical space the solder takes up in commonly used ball grid array (BGA) chip package. It saves even more space in 3D configurations such as this example. The gray circles are the solder balls.