A microelectronic 
assembly includes two or more microelectronic packages stacked at a 
fine pitch, which is finer than the 
pitch that is possible when using solder balls for making the joint. Each stackable 
package desirably includes a substrate having pins projecting from one surface of the substrate and solder balls projecting from the other surface of the substrate. Each stackable 
package may have one or more die attached to one or more of the surfaces of the substrate. In certain embodiments, die may be attached to both surfaces of the substrate. The dies may be electrically interconnected with the substrate using wire bonds, 
flip chip bonding, leads and / or stud bumping. The die may be encapsulated in an encapsulated material, under-filled or glob topped. In certain preferred embodiments, the combination of the conductive post height and ball height is equal to or greater than the height of the encapsulated or molded 
chip structure. The combination of the conductive post height and the ball height must be at least equal to the height of the encapsulated 
chip structure so that the conductive elements are able to span the gap between 
layers of the 
assembly. After the tips of the conductive pads are in contact with the solder masses, the solder masses are reflowed to form a permanent electrical 
interconnection between the stacked microelectronic packages. During reflow, the reflowed solder will wick up around the conductive posts to form elongated solder columns. In addition, when the solder is reflowed, 
surface tension pulls the opposing 
layers of the 
assembly toward one another and provides a self-centering action for the conductive posts.