A stacked chip assembly includes individual units having chips mounted on dielectric
layers and traces on the dielectric layers interconnecting the contacts of the
chips with terminals disposed in peripheral regions of the dielectric layers. At
least some of the traces are multi-branched traces which connect chip select contacts
to chip select terminals. The units are stacked one above the other with corresponding
terminals of the different units being connected to one another by solder balls
or other conductive elements so as to form vertical buses. Prior to stacking, the
multi-branched traces of the individual units are selectively interrupted, as by
breaking the individual branches, so as to leave chip select contacts of chips
in different units connected to different chip select terminals and thereby connect
these chips to different vertical buses. The individual units desirably are thin
and directly abut one another so as to provide a low-height assembly with good
heat transfer from chips within the stack.
