WLP BAW DEVICE WITH THROUGH-WLP VIAS

The present disclosure relates to a wafer-level packaged (WLP) bulk acoustic wave (BAW) device, which includes a BAW resonator, a WLP enclosure, and an interconnect. The BAW resonator includes a piezoelectric layer with an opening, a bottom electrode lead underneath the opening, and an interface structure extending over the opening and in contact with the bottom electrode lead through the opening. The WLP enclosure includes a cap, an outer wall that extends from the cap toward the piezoelectric layer to form a cavity, and a through-WLP via that extends through the cap and the outer wall and is vertically aligned with the opening of the piezoelectric layer. A portion of the interface structure is exposed to the through-WLP via. The interconnect is formed in the through-WLP via and electrically connected to the interface structure.