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US 6,611,182 B2Granted
Piezoelectric filter with decreased adhesive layer thickness and modulus of elasticity and manufacturing method therefor
AssigneeMurata Manufacturing Co., Ltd.
InventorShigeo Ojima
Life of this patent
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Abstract
An energy-trap piezoelectric filter has a construction such that first and second piezoelectric substrates are laminated with an adhesive sheet therebetween. The elasticity modulus of the adhesive sheet is within the range of about 0.5 MPa to about 3000 MPa. In addition, the adhesive sheet is provided with at least one notch in which a material that is used to form external electrodes is inserted.
Claims20
A piezoelectric filter comprising:
- a first piezoelectric substrate including a first piezoelectric filter unit and a first transfer capacitor unit;
- a second piezoelectric substrate including a second piezoelectric filter unit and a second transfer capacitor unit;
- an adhesive layer having a thickness between about 60 μm and about 200 μm and disposed between the first and the second piezoelectric substrates so that a laminate including the first and the second piezoelectric substrates and said adhesive layer is defined;
- and
- a plurality of external electrodes disposed on the outwardly facing surfaces of said laminate;
- wherein the modulus of elasticity of said adhesive layer is in the range of about 0.5 MPa to about 3000 MPa, said adhesive layer having at least one notch at the edge, and a material from which the external electrodes are formed is disposed into said at least one notch.
3 more elements
A method of manufacturing a piezoelectric filter, comprising the steps of:
- preparing a first piezoelectric substrate, which includes a first piezoelectric filter unit and a first transfer capacitor unit, and a second piezoelectric substrate, which includes a second piezoelectric filter unit and a second transfer capacitor unit;
- forming a laminate by laminating the first and the second piezoelectric substrates with an adhesive formed therebetween, said adhesive having a thickness between about 60 μm and about 200 μm;
- and
- forming a plurality of external electrodes on the outwardly facing surfaces of said laminate;
- wherein the modulus of elasticity of said adhesive after being cured is in the range of about 0.5 MPa to about 3000 MPa, said adhesive which is disposed between the first and the second piezoelectric substrates is provided with at least one notch at an edge thereof, and the external electrodes are formed in a manner such that a material from which the external electrodes are formed is inserted into said at least one notch.
2 more elements
Dependencies are inferred from the claim text.