3-D package having plurality of substrates

A package comprising:

• an interposer free from active devices therein, wherein the interposer comprises:
• a silicon substrate comprising a plurality of trenches extending from a bottom surface of the silicon substrate into the silicon substrate;
• redistribution lines over the silicon substrate;
• and
• a first plurality of connectors over and electrically coupled to the redistribution lines;
• a first die over and bonded to the first plurality of connectors, wherein the first die comprises:
• a first semiconductor substrate;
• a first plurality of through-vias in the first semiconductor substrate;
• and
• metal pillars electrically coupled to the first plurality of through-vias;
• and
• a second plurality of connectors over the first die, wherein the second plurality of connectors is electrically coupled to the first plurality of connectors through the first plurality of through-vias and the metal pillars in the first semiconductor substrate.

A package comprising:

• an interposer free from active devices therein, the interposer comprising:
• a first substrate free from through-vias therein;
• and
• redistribution lines over the first substrate;
• and
• a first die over and bonded to the interposer;
• a second die over and bonded to the interposer, wherein the first die and the second die are electrically coupled to each other through the redistribution lines;
• and
• a second plurality of connectors over the first die and the second die, wherein the second plurality of connectors is electrically coupled to the redistribution lines.