Semiconductor packages including active package substrates are described. In an example, the active package substrate includes an active die between a top substrate layer and a bottom substrate layer. The top substrate layer may include a via and the active die may include a die pad. An anisotropic conductive layer may be disposed between the via and the die pad to conduct electrical current unidirectionally between the via and the die pad. In an embodiment, the active die is a flash memory controller and a memory die is mounted on the top substrate layer and placed in electrical communication with the flash memory controller through the anisotropic conductive layer.