Emerging Technologies:

Limitations in system thickness and form factor are now limited by solder ball diameters and the passive elements such as decoupling capacitors, inductors, and resistors that are essential for power management and signal matching,  Bare Die Integration: R3 is currently developing new fabrication and assembly processes for integrating bare die onto and within flexible substrates without using solder contacts.  While MI is capable of reliable solder deposition down to 40 micron diameter for BGA applications, solder contact pitch is limited in order to ensure high reliability for chip-to-substrate soldering.  This pitch limitation severely limits the I/O count of the interface which is ever increasing for high performance products.  In lieu of solder contacts, MI is pursuing thermocompression and thermosonic fusion bonding of metal contacts such as gold studs to nickel/gold pads and copper pillar to copper pad connections to facilitate high density chip interconnectivity with 5 micron precision.

Integrated Passive Development:    
R3 is now limited in volumetric scaling by the passive devices that are used to manage power and signal integrity.  Currently in fabrication development are low profile, on-chip inductors and transformers for our R3 Magnetics Group.  These components are fabricated in the same production process flow as the Thin-film Flex Interposer (TFI) substrates and therefore can be directly co-fabricated into a system design as needed.
On the near horizon, are efforts to integrate high density capacitors in silicon using Deep Reactive Ion Etching (DRIE) to form high aspect ratio mold structures that substantially enhance surface area in a fixed volume.  In addition, MI is pursuing printing of resistive traces so that all passive device requirements can be met and co-fabricated into the MCM.
 Further on the horizon is inclusion of on substrate power sources such as lithium-silicon batteries and energy scavenging and sensor transducer devices such as ThermoElectric Generators (TEGs) or piezoelectrics elements.  Finally, the ultimate goal of MCM integration will be intelligent substrates with co-fabricated routing glue logic for dynamic system operation and power management.