MCMs, Embedded Die and 3D
Thinned Si Die on Flex: Assembly
processes have been developed for
assembly of flip chip die as thin as
20m to be assembled on polyimide
and liquid crystal polymer (LCP) flex
substrates. Lamination processes have
also been developed to embed the Si die
between sheets of LCP. The target
applications for this technology include
distributed electronics on membrane
antenna for space based radars,
wearable
electronics
and
multifunctional building blocks. The
technology also provides the basis for
3D electronics with the silicon
embedded in the substrate.
Embedded Si Die: Processes have
been developed at Auburn to embed
thinned (50m) die between layers of
liquid crystal polymer (LCP) film. The
target applications include distributed
electronics in membrane antenna for
space based radar, wearable electronics
and multifunctional structures. The
technology is also extendable to 3D
electronics by stacking LCP layers
with embedded Si die.
LCP substrate with
thick electroplated Au
Placed transferred die
Thermal compression
bonding
Release handle
Sealing with a
coverlayer LCP
Multichip Modules: Auburn has developed a
multilayer Cu/polyimide process on Si, AlN and
Si3N4 substrates to fabricate multichip modules.
Decoupling capacitors and resistors are also being
fabricated as part of the substrate fabrication. The
semiconductor die are attached and interconnected to
the substrate using wire bonding and flip chip
assembly. Additional passive components are
surface mount soldered to the substrate. The
assembled module is then packaged in a ceramic
package and sealed.
Die Stacking: Auburn researchers have evaluated
materials and demonstrated processes for stacking die
in a BGA package. Wire bonding was used to provide
the vertical interconnections between the die and the
package. Die stacking provides one method of 3D
pacakging which is used widely in the cell phone
industry.