A vertical routing structure inside a substrate for connecting a pair of trace lines electrically. The trace lines are positioned on the top and bottom surface of a stack layer. The vertical routing structure includes a conductive rod and two bonding pads. The conductive rod passes through the stack layer such that the top and bottom surface of the conductive rod are also exposed on the top and bottom surface of the stack layer. In addition, a bonding pad is also attached to the top and bottom surface of the conductive rod respectively. The bonding pads are connected to the aforementioned trace lines. The two bonding pads have a transverse sectional area smaller than the transverse sectional area of the conductive rod. Thus, the vertical routing structure is able to reduce surface area needed to accommodate inter-layer connections and increase routing density within the substrate.
The present invention provides a system and method for selectively stacking and interconnecting leaded packaged integrated circuit devices with connections between the feet of leads of an upper IC and the upper shoulder of leads of a lower IC while conductive transits that implement stacking-related intra-stack connections between the constituent ICs are implemented in multi-layer interposers or carrier structures oriented along the leaded sides of the stack, with selected ones of the conductive transits electrically interconnected with other selected ones of the conductive transits.
