A 3-D Pillar-Based Electromagnetic Interference Shield for W-Band Antenna on Silicon Using Wire Bonding Technology

This letter presents a 3-D electromagnetic interference (EMI) shield fabricated by a commercially available wire bonding technology to reduce EMI between a
$W$
-band (94 GHz) integrated-passive-device (IPD) antenna and other function blocks in a package. This EMI shield consists of vertical pillars fabricated by cutting out the wires created from the gold (Au) stud bumps, which are bonded on the nickel/gold (Ni/Au) pads surrounding the IPD antenna that adopts a cavity-backed slot structure. The heights of these wire pillars are made around
$500~\mu \text{m}$
for being higher than that of a normal CMOS chip. The measured isolation (
$-S_{21}$
) from the transmitter (TX) IPD antenna to the receiver (RX) IPD antenna, each equipped with this EMI shield, demonstrates the EMI shielding functionality at 93.1–95.5 GHz and maximum shielding effectiveness (SE) of 16.92 dB at 94.2 GHz.