Embedded-dice-inside type substrate structure with redistribution layer covered on both side and method thereof

The invention discloses an embedded-dice-inside type substrate structure with redistribution layers covered on both side and the method thereof. The substrate structure comprises a first substrate with a metal pad, a first lead circuit on the upper surface of the first substrate, a second lead circuit on the bottom surface of the first substrate, and a die disposed on the metal pad. A die opening is arranged on the second substrate for accommodating the die, a third lead circuit is arranged on the upper surface of the first substrate, and a second lead circuit is arranged on the bottom surface of the first substrate. An adhesive layer is filled into the gap between the back surface of the die and the upper surface of the first substrate and the gap between the side wall of the die and the side wall of the die opening, and applied onto the back side of the second substrate.