A cavity printed circuit board (PCB) that allows electronic components with different dimensions disposed therein is provided. A cavity with a desired dimension is formed in the cavity PCB where the electronic components may be mounted and soldered therein. The cavity formed in the cavity PCB may also provide additional flexibility regarding placements and locations where the electronic components may be disposed in the 3D vertical stacking and packaging of the IC devices so as to provide alternatives of using different types of wiring or interconnection structures or fine-pitch connection lines among the electronic components.