An In-Situ Microcroaxial Fabrication and Attachment Strategy
Micro-coaxial cables (MCCs), with an outer diameter of 100 μm or less, enable a
new microelectronics packaging platform that will reduce the time required to design and
fabricate complex multi-chip microelectronic assemblies. Low-inductance MCCs for power
distribution and 30-75 Ω MCCs for signal distribution, eliminate the need for
lengthy simulations and fabrication processes, as ... read morein board design of
photo-lithographically patterned microchips, because each individually shielded MCC
provides sufficient isolation to prevent electro-magnetic interference (EMI) and
crosstalk. The in-situ fabrication method presented here utilizes only conventional wire
bonding and microfabrication techniques, providing a high-feasibility path toward a new
interconnect paradigm based on MCCs. Each cable measured consists of a 25.4 μm
gold bond wire coated first with a dielectric and then a 5.0 μm thick gold shield.
For power distribution, the dielectrics evaluated are 1.0 μm thick Parylene C
dielectric and 100 nm thick HfO2. Their characteristic impedances are measured to be
3.2-5.9 Ω and 0.11-0.18 Ω, respectively. A third MCC, appropriate for
signals, has a 38 μm thick Parylene C dielectric and a characteristic impedance of
39-68 Ω. For a wire pitch of 0.51 mm cross-talk is -62 dB at 1 GHz for micro-coax.
Cross-talk increases to -30 dB at 26.5 GHz.
Thesis (M.S.)--Tufts University, 2018.
Submitted to the Dept. of Mechanical Engineering.
Advisors: Robert White, and Caprice Gray.
Committee: Marc Hodes.
Keywords: Packaging, Electrical engineering, and Mechanical engineering.read less