US 12,355,414 B2
Surface acoustic wave filter wafer-level packaging structure and method
Guojun Weng, Shenzhen (CN)
Assigned to Shenzhen Newsonic Technologies Co., Ltd., Shenzhen (CN)
Filed by Shenzhen Newsonic Technologies Co., Ltd., Shenzhen (CN)
Filed on Nov. 18, 2022, as Appl. No. 18/056,799.
Prior Publication US 2023/0081950 A1, Mar. 16, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H03H 3/08 (2006.01)
CPC H03H 3/08 (2013.01) 8 Claims
OG exemplary drawing
 
1. A fabrication method of a surface acoustic wave (SAW) filter, comprising:
obtaining a filter wafer, comprising:
obtaining a first substrate; and
forming an interdigital transducer (IDT) on the first substrate, the IDT including a first input and output end, a second input and output end, and an interdigital portion;
forming a dielectric layer on the filter wafer, the dielectric layer covering the first input and output end and the second input and output end of the IDT, and exposing the interdigital portion;
forming a passivation layer on the dielectric layer;
forming a bonding layer on the passivation layer; and
bonding a second substrate to the filter wafer via the bonding layer,
wherein a cavity is enclosed by the second substrate and the bonding layer, and the forming the bonding layer on the passivation layer comprises:
sputtering, in a vacuum environment, the second substrate to deposit the bonding layer on a top surface and side surfaces of the passivation layer.