EMI Shielding structure in InFO package

1. A method comprising:

forming a metal post over a first dielectric layer;

attaching a second dielectric layer over the first dielectric layer;

encapsulating a device die, the second dielectric layer, a shielding structure, and the metal post in an encapsulating material;

planarizing the encapsulating material to reveal the device die, the shielding structure, and the metal post; and

forming a first antenna electrically coupling to the device die, wherein the first antenna has a portion vertically aligned to a portion of the device die.

2. The method of claim 1 further comprising forming the shielding structure comprising:

attaching a metal film over the second dielectric layer; and

forming a side-shielding structure over the metal film, wherein the side-shielding structure and the metal film in combination form the shielding structure.

3. The method of claim 1 further comprising forming the shielding structure comprising:

attaching a metal film over the second dielectric layer;

after the encapsulating, forming an opening in the encapsulating material to reveal a portion of the metal film; and

filling a conductive paste into the opening to form a side-shielding structure over the metal film, wherein the side-shielding structure and the metal film in combination form the shielding structure.

4. The method of claim 1 further comprising:

pre-forming the shielding structure;

attaching the device die to the shielding structure; and

attaching the pre-formed shielding structure and the device die as an integrated unit over the second dielectric layer.

5. The method of claim 1 further comprising:

spraying a conductive paste onto a surface and a sidewall of the device die to form the shielding structure; and

attaching the shielding structure and the device die as an integrated unit over the second dielectric layer.

6. The method of claim 1 further comprising:

forming a third dielectric layer, with the third dielectric layer and the device die being on opposite sides of the second dielectric layer; and

forming a second antenna on the third dielectric layer, wherein the second antenna is electrically decoupled from the first antenna, and is configured to signally couple to the first antenna through electromagnetic field, and the first antenna and the second antenna in combination form a stacked patch antenna.

7. The method of claim 1 further comprising electrically grounding the shielding structure.

8. A method comprising:

forming a first dielectric layer over a carrier;

attaching a second dielectric layer to the first dielectric layer;

disposing a metal film over the second dielectric layer;

forming a side-shielding structure over the metal film;

attaching a device die to the metal film, wherein the device die is in a region encircled by the side-shielding structure;

encapsulating the device die and the side-shielding structure in an encapsulating material; and

forming a first antenna, wherein the first antenna and the device die are on opposite sides of the second dielectric layer, and the first antenna is electrically coupled to the device die.

9. The method of claim 8 further comprising forming a plurality of redistribution lines, wherein the first antenna and the device die are further interconnected through the plurality of redistribution lines.

10. The method of claim 8 further comprising forming a metal post, wherein the encapsulating material encapsulates the metal post, and the first antenna and the device die are further interconnected through the metal post.

11. The method of claim 10 , wherein the metal post and the side-shielding structure are formed sharing a common plating process.

12. The method of claim 8 , wherein the forming the side-shielding structure comprises:

depositing a metal seed layer over the first dielectric layer, the second dielectric layer, and the metal film, with the side-shielding structure formed starting from the metal seed layer; and

removing portions of the metal seed layer, with remaining portions of the metal seed layer being parts of the side-shielding structure.

13. The method of claim 8 , wherein a portion of the first antenna is vertically aligned with a portion of the device die.

14. The method of claim 8 further comprising:

forming a third dielectric layer, with the third dielectric layer and the device die being on opposite sides of the second dielectric layer; and

forming a second antenna on the third dielectric layer, wherein the second antenna is electrically decoupled from the first antenna, and the first antenna and the second antenna in combination form a stacked patch antenna.

15. A method comprising:

attaching a pre-formed dielectric layer over a carrier;

disposing a metal film over the pre-formed dielectric layer;

forming a side-shielding structure over and electrically coupling to the metal film, wherein the side-shielding structure forms a ring;

placing a device die in a region over the metal film, wherein the device die is encircled by the ring formed of the side-shielding structure;

encapsulating the device die and the side-shielding structure in an encapsulating material;

de-mounting the pre-formed dielectric layer, the device die, the metal film, and the side-shielding structure from the carrier; and

forming a first antenna, wherein the first antenna and the device die are on opposite sides of the pre-formed dielectric layer.

16. The method of claim 15 , wherein the first antenna and the device die are electrically inter-coupled.

17. The method of claim 15 further comprising forming a metal post, wherein the encapsulating material encapsulates the metal post, and the first antenna and the device die are further interconnected through the metal post.

18. The method of claim 17 further comprising performing a planarization process on the encapsulating material to reveal both the metal post and the side-shielding structure.

19. The method of claim 17 , wherein metal post and the side-shielding structure are formed in a common plating process.

20. The method of claim 15 further comprising:

forming an additional dielectric layer, with the additional dielectric layer and the device die being on opposite sides of the pre-formed dielectric layer; and

forming a second antenna on the additional dielectric layer, wherein the second antenna is electrically decoupled from the first antenna, and the first antenna and the second antenna in combination form a stacked patch antenna.