Bulk acoustic wave filter element and forming method thereof, multiplexer and communication equipment

A bulk acoustic wave filter and filter technology, which is applied in the field of filters, can solve problems such as occupation and the space occupied by the bulk acoustic wave filter is difficult to reduce, and achieve the effects of reducing the plane area, reducing the volume, and improving the roll-off performance

CN111327296AActive Publication Date: 2020-06-23ROFS MICROSYST TIANJIN CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2020-06-23

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Abstract

The invention relates to the technical field of filters, in particular to a bulk acoustic wave filter element and a forming method thereof, a multiplexer and communication equipment, and the method comprises the following steps: arranging one part of resonators on an upper wafer, and arranging the other part of resonators on a lower wafer; wherein the upper wafer and the lower wafer are stacked; and the butt joint pin of the upper wafer is bonded with the butt joint pin of the lower wafer, so that the resonators of the upper wafer and the lower wafer are connected to form the filter. Accordingto the technical scheme of the invention, the resonators are respectively arranged on the upper wafer and the lower wafer, and the resonators on the upper wafer and the lower wafer are bonded throughthe butt joint pins to form the filter, so that the planar area occupied by the resonators in the upper wafer and the lower wafer can be reduced, and the size of the filter can be reduced.
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Description

technical field

[0001] The invention relates to the technical field of filters, in particular to a bulk acoustic wave filter element and a forming method thereof, a multiplexer and communication equipment. Background technique

[0002] The miniaturization and high performance of the communication system is the future development trend. In the communication system, the bulk acoustic wave filter occupies a large part of the space, so the miniaturization and high performance of the bulk acoustic wave filter are very important. The size of a bulk acoustic wave filter mainly depends on the area occupied by the internal resonator. Under the limitation of frequency and material requirements, it is difficult to further reduce the size of a single resonator. When the resonator is fabricated on a silicon substrate, the area occupied by a filter element is also fixed. The area used by the resonator in the filter can be reduced as much as possible through the design of the resonator, b...

Examples

Embodiment Construction

[0055] figure 2 is a cross-sectional view of a bulk acoustic wave filter element provided by an embodiment of the present invention, figure 2In the above, the resonator resonator is manufactured on both the upper wafer (wafer 1) and the lower wafer (wafer 2), and the wafer 1 and wafer 2 are bonded through the butt pin PAD to form a filter. The resonators on wafer 1 and the resonators on wafer 2 need to meet certain spacing requirements to adjust the capacitance between the resonators, so as to realize the adjustment of the equivalent kt of the resonators, and then ensure certain performance requirements. Specifically, the spacing D needs to satisfy 0<D≤50um (micrometer), and more specifically, D needs to satisfy 1um≤D≤10um.

[0056] image 3 is an arrangement mode of a resonator according to an embodiment of the present invention, image 3 In the figure, the solid line is a series resonator, which can be set on wafer 1 or wafer 2. On the contrary, the parallel resonator i...