Method of forming a dummy die of an integrated circuit having an embedded annular structure

1. A method comprising:

attaching an integrated circuit die to a first substrate;

forming a dummy die;

attaching the dummy die to the first substrate adjacent the integrated circuit die;

forming an encapsulant over the first substrate and surrounding the dummy die and the integrated circuit die;

planarizing the encapsulant, the dummy die and the integrated circuit die, a topmost surface of the encapsulant being substantially level with a topmost surface of the dummy die and a topmost surface of the integrated circuit die; and

removing an interior portion of the dummy die, a remaining portion of the dummy die forming an annular structure.

2. The method of claim 1 , wherein forming the dummy die comprises:

patterning a second substrate to form an opening in the second substrate, the opening having an annular shape in a plan view; and

depositing an insulating material in the opening.

3. The method of claim 2 , wherein planarizing the encapsulant, the dummy die and the integrated circuit die comprises exposing the insulating material.

4. The method of claim 2 , wherein removing the interior portion of the dummy die comprises:

removing the insulating material, wherein the dummy die is separated into an interior region and a peripheral region after removing the insulating material; and

picking up the interior region from the first substrate, the peripheral region forming the annular structure.

5. The method of claim 4 , wherein removing the insulating material comprises removing the insulating material using a laser drilling method.

6. The method of claim 1 , wherein the dummy die is attached to the first substrate using an adhesive.

7. The method of claim 1 , further comprises:

placing a functional component within the annular structure; and

bonding the functional component to the first substrate, wherein the functional component and the annular structure have different heights.

8. A method comprising:

attaching an integrated circuit die to a first side of a first substrate;

forming a dummy die, the dummy die comprising a first annular structure within the dummy die;

attaching the dummy die to the first side of the first substrate adjacent the integrated circuit die;

forming a molding compound over the first substrate and surrounding the dummy die and the integrated circuit die, a top surface of the molding compound being substantially level with a topmost surface of the dummy die, a topmost surface of the first annular structure, and a topmost surface of the integrated circuit die;

removing the first annular structure, the dummy die being separated into an interior region and a peripheral annular region after removing the first annular structure;

detaching the interior region of the dummy die from the first substrate, the peripheral annular region of the dummy die forming a second annular structure;

placing a functional component on the first side of the first substrate within the second annular structure; and

attaching the functional component to the first side of the first substrate.

9. The method of claim 8 , wherein forming the dummy die comprises:

patterning a second substrate to form an opening in the second substrate, the opening having an annular shape in a plan view; and

depositing an insulating material in the opening to form the first annular structure.

10. The method of claim 8 , wherein removing the first annular structure comprises performing a laser drilling process.

11. The method of claim 8 , wherein the dummy die is attached to the first side of the first substrate using an adhesive.

12. The method of claim 8 , wherein the functional component and the second annular structure have different heights.

13. The method of claim 8 , further comprising forming a plurality of connectors on a second side of the first substrate, the second side of the first substrate being opposite the first side of the first substrate.

14. The method of claim 8 , wherein the first substrate comprises an interposer.

15. A method comprising:

attaching a first integrated circuit die to a first side of a first substrate;

attaching a second integrated circuit die to the first side of the first substrate adjacent the first integrated circuit die;

forming a dummy die, the dummy die comprising:

an interior region;

a first annular structure surrounding the interior region; and

a peripheral annular region surrounding the first annular structure;

attaching the dummy die to a top surface of the second integrated circuit die;

encapsulating the first integrated circuit die, the second integrated circuit die and the dummy die in a molding compound;

planarizing the molding compound to expose a top surface of the dummy die, a top surface of the first annular structure and a top surface of the first integrated circuit die;

removing the first annular structure;

removing the interior region of the dummy die to expose the top surface of the second integrated circuit die;

placing a functional component within the peripheral annular region of the dummy die; and

electrically coupling the functional component to the second integrated circuit die.

16. The method of claim 15 , wherein a height of the functional component is greater than a height of the first annular structure.

17. The method of claim 15 , wherein the first annular structure comprises an insulating material.

18. The method of claim 15 , wherein forming the dummy die comprises:

etching a second substrate to form an opening in the second substrate, the opening having an annular shape in a plan view; and

filling the opening with an insulating material to form the first annular structure.

19. The method of claim 18 , wherein a ratio of a width of the opening to a depth of the opening is between about 0.35 and about 0.7.

20. The method of claim 15 , wherein removing the first annular structure comprises etching the first annular structure.