Stackable microelectronic package structures

1. A method for making a microelectronic assembly, comprising:

assembling a first microelectronic package with a second microelectronic package, the second microelectronic package overlying the first microelectronic package and having terminals thereon, the first microelectronic package including:

a substrate having first and second opposed surfaces and substrate contacts thereon;

first and second microelectronic elements each having element contacts electrically connected with the substrate contacts, the first and second microelectronic elements being spaced apart from one another on the first surface so as to provide an interconnect area of the first surface between the first and second microelectronic elements;

third and fourth microelectronic elements spaced on opposite sides of the interconnect area between the first and second microelectronic elements;

a plurality of package terminals at the second surface electrically interconnected with the substrate contacts for connecting the package with a component external to the package; and

a plurality of stack terminals exposed at the first surface in the interconnect area for connecting the package with a component overlying the first surface of the substrate; and

connecting the terminals of the second microelectronic package with the stack terminals of the first microelectronic package to form an electrical connection between the second microelectronic package and the first, second, third, and fourth microelectronic elements of the first package.

2. The method of claim 1 , wherein the step of connecting the terminals of the second microelectronic package with the stack terminals of the first microelectronic package includes joining the package terminals to exposed ends of interconnects on an encapsulant layer of the first microelectronic package overlying the first surface of the substrate at least in the interconnect area thereof, the interconnects being joined to the stack terminals opposite the exposed ends thereof.

3. The method of claim 1 , wherein the step of connecting the terminals of the second microelectronic package with the stack terminals of the first microelectronic package includes depositing conductive bond material masses into holes within an encapsulant layer of the first microelectronic package overlying the first surface of the substrate at least in the interconnect area, the stack terminals being exposed at a surface of the encapsulant layer within the holes, and wherein the conductive bond material masses are joined to the terminals of the second package and the stack terminals of the first package.

4. The method of claim 1 , wherein the step of connecting the terminals of the second microelectronic package with the stack terminals of the first microelectronic package includes:

forming a plurality of holes through at least an encapsulant of the first microelectronic package overlying the first surface of the substrate in at least the interconnect area thereof, the plurality of holes being aligned with respective ones of the stack terminals at first ends thereof and with corresponding ones of the terminals of the second package at second ends thereof; and

filling the holes with a conductive material in contact with the stack terminals of the first microelectronic package and the package terminals of the second package.

5. The method of claim 4 , wherein the holes are further formed through the substrate of the first package and through the respective stack terminals thereof.

6. The method of claim 4 , wherein the holes are further formed through a substrate of the second package and through the corresponding terminals thereof.