3D Stacking

Goal: create 3D cubes of silicon
Process:
- “Thin” die to 7 mils or smaller
- “Glue” together
- Plate wires on sides
Stacks of 70 or more have been demonstrated
Ideal for PIMs
- Same chip type throughout
- Most side wires: common or chip-chip
- “Contact explosion” avoidable
Problems Today: >2 side wiring, Power