WLCSP
This package is very small and cheap to produce. It also has benefits due to the lack of bond wires. Bond wires increase parasitic inductance, and can be a problem for high speed designs.
The downside is that they are very tiny!
The last 5 layers of the Skywater PDK define the layers necessary to build the WLCSP package.
Course feedback
ASICs are a chunk of the stack that just seems so impenetrable because typically you need enormous amounts of money and access to PDKs and Cadence and all this stuff. It seemed like an awesome way to fill in that missing piece of how computers work top to bottom.
Ben Newhouse (digital course)