Stacked semiconductor package formed on a substrate and method for fabrication

A stacked semiconductor package formed on a substrate arranged in a serpentine configuration comprising:

• a first substrate section formed on a first section of said substrate having an insulating layer bonded to and a first plurality of I/O pads formed on a bottom surface, a first plurality of solder balls formed on said first plurality of I/O pads, a second plurality of I/O pads formed on a top surface through said first section of the substrate, a second plurality of solder bumps formed on said second plurality of I/O pads, and a third plurality of metal wiring formed in said insulating layer providing electrical communication between said first plurality of I/O pads and said second plurality of I/O pads;
• a first IC die having a fourth plurality of solder bumps formed in an active surface for bonding to said second plurality of solder bumps formed in said first substrate section;
• a second substrate section formed on a second section of said substrate having an insulating layer bonded to and a first plurality of I/O pads formed on a top surface, a second plurality of I/O pads formed on a bottom surface through said second section of the substrate, a second plurality of solder bumps formed on said second plurality of I/O pads, and a third plurality of metal wiring formed in said insulating layer providing electrical communication between said first and said second plurality of I/O pads;
• a second IC die having a fourth plurality of solder bumps formed in an active surface for bonding to said second plurality of solder bumps formed in said second substrate section;
• and
• a first U-shaped section of said substrate integrally connecting said first and said second section of the substrate such that an inactive surface of said first IC die is adhesively bonded to an inactive surface of said second IC die in a back-to-back relationship forming said stacked semiconductor package.