Electromagnetic interference shielding package structures and fabricating methods thereof
The present disclosure provides a semiconductor structure, comprising a die/die stack attached on a substrate, a conductive top block covering a top surface of the die/die stack, and a plurality of ground wires conductively connect the conductive top block and to the substrate. The conductive top block, the plurality of ground wires, and the substrate form a Faraday cage to provide an electromagnetic interference shielding of the die/die stack.
1 . A semiconductor structure, comprising:
a first die/die stack attached on a substrate;
a conductive top block including a conductive material, the conductive material attached to semiconductor material at a top surface of the first die/die stack; and
a plurality of ground wires conductively connecting the conductive top block to the substrate;
wherein the conductive top block, the plurality of ground wires, and the substrate form a Faraday cage to provide electromagnetic interference shielding to the first die/die stack.
2 . The semiconductor structure of claim 1 , wherein:
the plurality of ground wires are surrounding the first die/die stack; and
a size of the conductive top block is larger than a size of the first die/die stack in a plane substantially parallel to a major surface of the substrate, such that the top surface of the first die/die stack is completely covered by the conductive top block.
3 . The semiconductor structure of claim 1 , further comprising:
a mold compound layer on the substrate and covering the conductive top block and the plurality of ground wires; and
a plurality of solder balls attached to a bottom surface of the substrate.
4 . The semiconductor structure of claim 1 , wherein the conductive material is a conductive plate having a thickness between about 20 μm and about 100 μm, the conductive top block includes:
an insulating layer covering a top surface of the conductive plate; and
a plurality of bond pads embedded in the insulating layer and in electrical contact with the conductive plate.
5 . The semiconductor structure of claim 4 , wherein:
the conductive plate is a metal plate or a conductive polymer plate doped with a metal or a metal oxide; and
the plurality of bond pads are located adjacent to edges of the conductive top block, the bond pads having a thickness between about 0.5 μm and about 1 μm, and the bond pads having a bond pad pitch between about 50 μm and about 5 mm.
6 . The semiconductor structure of claim 1 , wherein:
the first die/die stack is attached to the substrate by a first adhesive film; and
the conductive top block is attached to the top surface of the first die/die stack by a second adhesive film different from the first adhesive film.
7 . The semiconductor structure of claim 6 , wherein:
the first adhesive film is a die attach film; and
the second adhesive film is a film over wire penetrated by a plurality of signal wires of the first die/die stack.
8 . The semiconductor structure of claim 1 , wherein the Faraday cage is a first Faraday cage, the semiconductor structure further comprising a second die/die stack without a second Faraday cage.
9 . The semiconductor structure of claim 8 , wherein the second die/die stack is located on a side of the first die/die stack in a lateral direction.
10 . The semiconductor structure of claim 8 , wherein the second die/die stack includes a three-dimensional NAND Flash device, and the first die/die stack includes a memory controller to control the three-dimensional NAND Flash device.
11 . The semiconductor structure of claim 8 , wherein the second die/die stack is located on a top surface of the conductive top block.
12 . A method of forming a semiconductor structure, comprising:
attaching a first die/die stack on a substrate;
forming a conductive top block having a size larger than the first die/die stack;
attaching the conductive top block to cover a top surface of the first die/die stack;
forming a plurality of ground wires to conductively connect the conductive top block and the substrate, such that the conductive top block, the plurality of ground wires, and the substrate form a first Faraday cage to provide electromagnetic interference shielding of the first die/die stack; and
forming a second die/die stack located on a top surface of the conductive top block, the second die/die stack without the first Faraday cage and without a second Faraday cage.
13 . The method of claim 12 , further comprising:
forming the plurality of ground wires surrounding the first die/die stack;
forming a mold compound layer on the substrate to cover the conductive top block and the plurality of ground wires; and
attaching a plurality of solder balls to a bottom surface of the substrate.
14 . The method of claim 12 , wherein forming the conductive top block comprises:
forming a conductive plate with a thickness between about 20 μm and about 100 μm;
forming an insulating layer covering a top surface of the conductive plate;
forming a plurality of bond pads having a thickness between about 0.5 μm and about 1 μm embedded in the insulating layer and in electrical contact with the conductive plate; and
arranging the plurality of bond pads adjacent to edges of the conductive top block, the plurality of bond pads having a bond pad pitch between about 50 μm and about 5 mm.
15 . The method of claim 12 , further comprising:
forming a conductive film having a thickness in a range from about 1 μm to about 20 μm on a top surface of a silicon wafer by spin coating, spraying, plating, or sputtering;
forming an insulating layer covering a top surface of the conductive film;
forming a plurality of bond pads having a thickness between about 0.5 μm and about 1 μm embedded in the insulating layer and in electrical contact with the conductive film; and
arranging the plurality of bond pads adjacent to edges of the conductive top block, the plurality of bond pads having a bond pad pitch between about 50 μm and about 5 mm.
16 . The method of claim 12 , further comprising:
forming at least one signal wire connecting the first die/die stack to the substrate, wherein a portion of the at least one signal wire penetrates a second adhesive film to attach the conductive top block.
17 . The method of claim 12 , further comprising:
forming a third die/die stack located on a side of the first die/die stack in a lateral direction without electromagnetic interference protection.