Method of fabricating stacked packages with bridging traces
View Patent ↗A microelectronic assembly that includes a first microelectronic element having a first rear surface. The assembly further includes a second microelectronic element having a second rear surface. The second microelectronic element is attached to the first microelectronic element so as to form a stacked package. A bridging element electrically connects the first microelectronic element and the second microelectronic element. The first rear surface of the first microelectronic element faces toward the second rear surface of the second microelectronic element.
1. A method, comprising the steps of:
forming a microelectronic assembly by stacking a first subassembly including a plurality of microelectronic elements onto a second subassembly including a plurality of microelectronic elements, including aligning respective saw lanes of each of the first and second subassemblies with one another, wherein each of the first and second subassemblies has a rear face, and the rear faces of the first subassembly and second subassembly confront one another;
dicing through the saw lanes of the first and second subassemblies so as to form individual stacked units; and
after the dicing step, forming electrically conductive bridging elements conforming to exterior surfaces of the individual stacked units, the bridging elements electrically connected with a plurality of contacts exposed at a front face of the first subassembly and with a plurality of respective contacts exposed at a front face of the second subassembly.
2. The method of claim 1 , wherein at least some of the plurality of microelectronic elements of each of the first subassembly and the second subassembly have traces that extend from respective contacts to the saw lanes of the respective first and second subassemblies such that after the dicing step the traces are exposed, wherein the bridging elements are formed to extend from the traces of the first subassembly to the traces of the second subassembly.
3. The method of claim 1 , wherein the first microelectronic element has a first edge, the second microelectronic element has a second edge, and the bridging elements are disposed outside of the first and second edges.
4. A method of assembling a stacked package comprising the steps of forming a first individual stacked unit and a second individual stacked unit according to claim 1 , further comprising electrically connecting at least some of the contacts of the first individual stacked unit to at least some of the contacts of the second individual stacked unit.