Integrated circuit package with molded cavity

1. A method of manufacture of an integrated circuit package system comprising:

providing a base substrate;

attaching a base die over the base substrate;

attaching an integrated interposer having interposer circuit devices, over the base die;

electrically connecting base package connectors between the base die and the integrated interposer; and

forming a package system encapsulant having an encapsulant cavity over the integrated interposer.

2. The method as claimed in claim 1 further comprising attaching a top package over the integrated interposer.

3. The method as claimed in claim 1 further comprising attaching a top package having an underfill.

4. The method as claimed in claim 1 wherein attaching the base die includes attaching a base package having the base die, over the base substrate.

5. A method of manufacture of an integrated circuit package system comprising:

providing a base substrate having base inner connections and base outer connections;

mounting a base die over the base inner connections;

mounting an integrated interposer having interposer circuit devices, interposer inner connections, and interposer outer connections, over the base die;

electrically connecting base package connectors between the base die and the integrated interposer;

molding a package system encapsulant having an encapsulant cavity over the interposer outer connections; and

mounting a top package over the interposer outer connections.

6. The method as claimed in claim 5 wherein mounting the base die includes pre-mounting the base die over the interposer inner connections.

7. The method as claimed in claim 5 wherein mounting the base die includes mounting a flip chip die over the interposer inner connections.

8. The method as claimed in claim 5 wherein mounting the integrated interposer includes mounting the integrated interposer having an offset from the base die.

9. The method as claimed in claim 5 wherein mounting the integrated interposer includes forming the integrated interposer having rectangular planar dimensions, openings, or a combination thereof.

10. The method as claimed in claim 5 wherein mounting the integrated interposer includes mounting base packages including the base die, and the top package over the integrated interposer.

11. The method as claimed in claim 5 wherein mounting the integrated interposer includes mounting a multi chip module having base packages including the base die.

12. An integrated circuit package system comprising:

a base substrate;

a base die over the base substrate;

an integrated interposer having interposer circuit devices, over the base die;

base package connectors electrically connected between the base die and the intergrated interposer; and

a package system encapsulant having an encapsulant cavity over the integrated interposer.

13. The system as claimed in claim 12 further comprising a top package over the integrated interposer.

14. The system as claimed in claim 12 further comprising a top package having an underfill.

15. The system as claimed in claim 12 wherein the base die is a base package having the base die, over the base substrate.

16. The system as claimed in claim 12 wherein:

the base substrate has base inner connections and base outer connections;

the base die is over the base inner connections;

the integrated interposer has interposer circuit devices, interposer inner connections, and interposer outer connections, over the base die;

the package system encapsulant having the encapsulant cavity is over the interposer outer connections on a side opposite the base die; and

further comprising:

a top package over the interposer outer connections on the side opposite the base die.

17. The system as claimed in claim 16 wherein the base die includes the base die pre-mounted, over the interposer inner connections.

18. The system as claimed in claim 16 wherein the base die is a flip chip die over the interposer inner connections.

19. The system as claimed in claim 16 wherein the integrated interposer includes the integrated interposer having an offset from the base die.

20. The system as claimed in claim 16 wherein the integrated interposer includes the integrated interposer having rectangular planar dimensions, openings, or a combination thereof.

21. The system as claimed in claim 16 wherein the integrated interposer includes base packages including the base die mounted over the integrated interposer.

22. The system as claimed in claim 16 wherein the integrated interposer includes a multi chip module having base packages including the base die.