Semiconductor assemblies with system and methods for conveying signals using through mold vias

Abstract

A semiconductor device has first and second dies forming a die stack. Molding material encapsulates the die stack and forms an upper molded surface of the die stack. First conductive traces are coupled to the first die and extend from between the first and second die to corresponding first via locations in the molding material beyond a first side edge of the die stack. Second conductive traces coupled to an active surface of the second die opposite the first die extend to corresponding second via locations. Each first via location is vertically aligned with one of the second via locations. Through mold vias extend through the molding material between vertically aligned via locations to contact with corresponding conductive traces of the first and second dies, while the molding material that extends between the first conductive traces and the upper molded surface is free from any TMV.