Package structures and methods of forming the same

1. A method comprising:

bonding a first die to a first side of an interposer, the interposer comprising a semiconductor substrate;

attaching a dummy die to the first side of the interposer, the dummy die being adjacent to the first die;

attaching a cover structure to backsides of the dummy die and the first die; and

bonding a package substrate to a second side of the interposer, the second side being opposite the first side.

2. The method of claim 1 , wherein the dummy die is made of silicon.

3. The method of claim 1 further comprising:

bonding a second die to the first side of the interposer, the second die comprising one or more memory dies, the cover structure being thicker than each of the one or more memory dies.

4. The method of claim 3 , wherein the cover structure is attached back sides of the first die, the second die, and the dummy die.

5. The method of claim 3 , wherein the first side of the interposer further comprises a redistribution structure on the semiconductor substrate of the interposer, the first die and the second die being bonded to the redistribution structure.

6. The method of claim 5 , wherein the interposer further comprises through vias extending through the semiconductor substrate of the interposer, the through vias being electrically coupled to the redistribution structure.

7. The method of claim 6 , wherein the second side of the interposer is bonded to package substrate by conductive connectors, the conductive connectors being electrically coupled to the through vias.

8. The method of claim 1 further comprising:

bonding a surface mount device bonded to the package substrate.

9. The method of claim 1 , wherein the first die comprises one or more logic dies.

10. The method of claim 1 further comprising:

bonding a second die to the first side of the interposer, the second die comprising one or more memory dies; and

forming an underfill between the first die and the first side of the interposer and the second die and the first side of the interposer.

11. The method of claim 10 further comprising:

forming an encapsulant adjacent the second die, the encapsulant contacting a sidewall of the second die and a sidewall of the underfill.

12. A method comprising:

bonding a first die to a first side of a first interposer;

bonding a stack of memory dies to the first side of the first interposer, the stack of memory dies comprising a top die, the top die being the furthest die in the stack of memory dies from the first side of the first interposer, the top die having a thickness greater than a thickness of each of the other dies in the stack of memory dies, the top die being a memory die; and

bonding a package substrate to a second side of the first interposer, the second side being opposite the first side.

13. The method of claim 12 , wherein the top die has a thickness greater than or equal to 120 μm.

14. The method of claim 12 further comprising:

forming an underfill between the first die and the first interposer and the stack of memory dies and the first interposer.

15. The method of claim 14 further comprising:

forming an encapsulant on the underfill between the first die and the stack of memory dies.

16. The method of claim 12 , wherein the first interposer comprises a substrate through vias extending through the substrate, the first die being electrically coupled to the through vias.

17. A structure comprising:

a first die bonded to a first side of a first substrate using first electrical connectors;

a dummy die attached to the first side of the first substrate in a scribe line region of the first substrate;

a cover structure attached to a backside of the first die;

an underfill between the first die and the first side of the first substrate, the underfill surrounding the first electrical connectors; and

an encapsulant on the first substrate, the underfill, and the cover structure and on sidewalls of the first die and the dummy die.

18. The structure of claim 17 , wherein the dummy die is made of silicon.

19. The structure of claim 17 , wherein the cover structure is attached to the backsides of the dummy die and the first die by an adhesive layer.

20. The structure of claim 17 , wherein backside surfaces of the first die and the dummy die are at a same level.