US 12,143,096 B2
Filter device and filter circuit
Kota Okubo, Nagaokakyo (JP); and Takayuki Okude, Nagaokakyo (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Mar. 2, 2021, as Appl. No. 17/189,339.
Claims priority of application No. 2020-058850 (JP), filed on Mar. 27, 2020; and application No. 2020-100850 (JP), filed on Jun. 10, 2020.
Prior Publication US 2021/0305967 A1, Sep. 30, 2021
Int. Cl. H03H 9/64 (2006.01); H03H 9/02 (2006.01); H03H 9/145 (2006.01); H03H 9/25 (2006.01)
CPC H03H 9/6483 (2013.01) [H03H 9/02543 (2013.01); H03H 9/145 (2013.01); H03H 9/25 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A filter device comprising:
a first substrate;
a first input electrode on the first substrate;
a first output electrode on the first substrate;
a first ground electrode on the first substrate and that receives a ground potential;
an open portion that is electrically open and provided in or on the first substrate;
a second substrate mounted on the first substrate;
a second input electrode on a surface of the second substrate and connected to the first input electrode;
a second output electrode on the surface of the second substrate and connected to the first output electrode;
a second ground electrode on the surface of the second substrate and connected to the first ground electrode; and
at least one first functional electrode on the surface of the second substrate and disposed on a first connecting path, the first connecting path connecting the second input electrode and the second output electrode; wherein
the open portion is connected to the first connecting path;
the first substrate is a multilayer substrate;
the open portion includes a plurality of electrodes on a plurality of layers of the multilayer substrate and being electrically connected with each other;
the plurality of electrodes include a connecting electrode on a surface of the multilayer substrate and which is connected to the first connecting path; and
the connecting electrode has a larger area than the plurality of electrodes other than the connecting electrode.