Abstract: A bump pad enclosure providing an improved reliability of a bump connection is provided. The bump pad enclosure comprises an electrode pad, a UBM and a first shield. The first shield covers at least a first perimeter area of the electrode pad. The first shield is provided and configured to shield the first perimeter area from a detrimental influence of the environment.

Abstract: A filter comprising first and second BAW resonators. The first BAW resonator having a piezoelectric layer, located between a top electrode and a bottom electrode, and a dielectric layer located between the bottom electrode and an additional electrode. Wherein the dielectric layer, the bottom electrode and the additional electrode are configured to provide an additional capacitance in the resonator. The second BAW resonator having at least one less electrode than the first BAW resonator.

Abstract: A BAW resonator (1) comprises a piezoelectric layer (2) located between a top electrode (4) and a bottom electrode (3) and comprises a dielectric layer (9) located between the bottom electrode (3) and an additional electrode (11), wherein the dielectric layer (9), the bottom electrode (3) and the additional electrode (11) are configured to provide an additional capacitance in the resonator (1). The BAW resonator (1) may be part of a ladder-type resonator arrangement (100).

Abstract: A method of manufacturing a filter circuit including series and parallel coupled BAW resonators is given which compensates for frequency tolerances of the resonators which are due to the manufacturing process. The new method includes measuring a resonance frequency of at least one type of the BAW resonators produced on a wafer and defining a deviation from a desired frequency. A trimming layer is then deposited onto the entire wafer. At last, a thickness portion of the trimming layer is selectively removed, the portion being dependent on a location on the wafer and on the calculated deviation of the resonance frequency at this location.

Abstract: A method of manufacturing a filter circuit including series and parallel coupled BAW resonators is given which compensates for frequency tolerances of the resonators which are due to the manufacturing process. The new method includes measuring a resonance frequency of at least one type of the BAW resonators produced on a wafer and defining a deviation from a desired frequency. A trimming layer is then deposited onto the entire wafer. At last, a thickness portion of the trimming layer is selectively removed, the portion being dependent on a location on the wafer and on the calculated deviation of the resonance frequency at this location.