Bulk acoustic wave filter and its package

摘要

A bulk acoustic wave filter device and its package. The filter devices greatly decreases the manufacturing process complexity by the coplanar electrode layout, and it omits the process steps of forming via hole of connectors, such that it is convenient to the coplanar high frequency on-wafer measurement and trimming. Furthermore, by using the wafer level chip scale package (WLCSP) technique, which to integrate the series resonator and the shunt resonator can be integrated, the spaces of filter can be saved and the cost of package can be down.