Wafer-level BCB CAP packaging of integrated MEMS switches with MMIC

This paper presents a BCB cap packaging of MEMS switches integrated with MMIC and its electrical and mechanical effects to the packaged devices have been also investigated. To prevent a possible breakage during BCB bonding process, the 100 µm-thick MMIC wafer is bonded to 680 µm-thick GaAs support that will be finally released using PMMA sacrificial etching. The implemented BCB caps on the target MMIC have the height of 28 µm and the cavity of 13 µm for the housing of MEMS switches. The achieved success rate of BCB caps transfer is approximately 80 %. The BCB cap packaging effect to microstrip line has been investigated through the S-parameters measurement before and after the packaging. Also, the packaged MEMS switch shows the insertion loss of 0.7 dB, the return loss of 25 dB and the isolation of 18 dB at 30 GHz.