Are the dies made for a BGA package any different from the dies for a QFN or a DIP Package? Do BGA dies have connections on the lower side of the die? In the substrate?
How are terminals put in the package under the die?
I came across this picture. Are BGA packages actually PCBs? and are signals just taken off the die edge and routed to the bottom of the package? If so, how does this help in decreasing inductance at high frequencies?
I also came across the image below which makes it look like the BGA packages have connections from the bottom side - from the substrate.