A Light-Weight Electromagnetic Shield Using High Density Carbon Nanotube Fence-Wall For Rf Packaging

A new isolation scheme to improve radio frequency isolation using high aspect carbon nanotube structures is demonstrated. Carbon nanotubes were designed on top of conventional via-fenced guard trace, and showed 10 dB improvement in radio frequency isolation over conventional via-fencing techniques. This shield made of carbon nanotubes have shown to attain similar isolation performance compared to that of Kovar, a common metal used as a guard ring, or cavity in radio frequency integrated circuits. With weight density less than a quarter to that of metals, complementary use of such CNT forest could lead to significant weight reduction in RF packages.