5G mmWave Patch Antenna Array on Extremely Low Loss Alumina Ribbon Ceramic Substrates for Antenna-in-Packaging (AiP)

The multi-layer capability of Corning's alumina ribbon ceramic (ARC) substrates for 5G mmWave Antenna-in-Packaging (AiP) is demonstrated on the $1\times 4$ array antenna using three $120\ \mu\mathrm{m}$ ARC substrates that have an extremely low dielectric loss, low profile, compactness, and good heat dissipation. The $1\times 4\ \text{mm}$ Wave array antenna is designed and fabricated by the laser ablation process, standard semi-additive metallization process, and Cu-Cu bonding with the Cu nitride passivation layer. The Cu nitride passivation layer allows lower process temperature and lower pressure than the conditions of direct Cu-Cu bonding. The fabricated $1\times 4$ array antenna is characterized including a beam steering. It has a simulated and measured peak gain of 11.2 dBi and 10.8 dBi, respectively, with a simulated 3-dB beamwidth of 26.3° in the H-plane and 82.1° in the E-plane. The beam can be steered up to 50° with 150° input phase difference between antenna elements.