Microelectronic packages having cavities for receiving microelectronic elements

1. A packaged microelectronic element, comprising:

a package element, said package element including:

a first dielectric element having a bottom face and a top face remote from said bottom face;

a plurality of package contacts and a plurality of first chip contacts exposed at said top face, said first chip contacts being connected to said package contacts,

a second dielectric element having a bottom face adjacent to said package contacts and a top face remote from said bottom face, said second dielectric element overlying said top face of said first dielectric element and having openings aligned with said package contacts;

a plurality of second chip contacts exposed at said bottom face of said second dielectric element;

a first microelectronic element having a plurality of bond pads connected to said chip contacts; and

a second microelectronic element having bond pads connected to said second chip contacts.

2. The packaged microelectronic element of claim 1 , wherein said microelectronic element further comprises a front face and a rear face, wherein said bond pads are exposed at said front face of the microelectronic element, and wherein bond wires connect said bond pads to said chip contacts.

3. The packaged microelectronic element of claim 1 , wherein said dielectric element has edges extending between said top and bottom faces, said edges being joined at corners, and corner regions at said corners having first width in a first direction interconnected by strip regions having a second width in said first direction smaller than said first width, wherein said package contacts are exposed at said corner regions.

4. The packaged microelectronic element of claim 1 , wherein said first dielectric element has an inner edge extending between said top and bottom faces, said inner edge defining an opening.

5. The packaged microelectronic element of claim 4 , wherein said inner edge of said first opening extends beyond said inner edge of said second opening is a ledge.

6. The packaged microelectronic element of claim 5 , wherein at least one of said plurality of chip contacts is exposed on said ledge.

7. The packaged microelectronic element of claim 4 , wherein said opening is a first opening and said second dielectric element has an inner edge extending between said top and bottom faces, said inner edge of said second dielectric element defining a second opening aligned with said first opening.

8. The packaged microelectronic element of claim 7 , wherein said first and second openings define an interior cavity of said packaged microelectronic element.

9. The packaged microelectronic element of claim 7 , wherein said inner edge of said first opening extends beyond said inner edge of said second opening.

10. The packaged microelectronic element of claim 8 , wherein said interior cavity is in the shape of a cross.

11. The packaged microelectronic element of claim 8 , wherein said interior cavity is in the shape of a rectangle.

12. The packaged microelectronic element of claim 1 , further comprising openings extending through said second dielectric element.

13. The packaged microelectronic element of claim 1 , wherein said package contacts on said top face of said first dielectric element are aligned with said openings.

14. The packaged microelectronic element of claim 8 , wherein said microelectronic element is laterally adjacent said packaged element.

15. The packaged microelectronic element of claim 1 , wherein said interior cavity of said packaged microelectronic element has interior projections and wherein said packaged microelectronic element further comprises a metal shelf disposed over said interior projections.

16. The packaged microelectronic element of claim 15 , wherein said microelectronic element has a top surface and a bottom surface and said metal shelf has a top surface and a bottom surface, said bottom surface of said microelectronic element attached to said top surface of said metal shelf.