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US 8,035,464 B1Granted
Bonded wafer SAW filters and methods
AssigneeTriQuint Semiconductor, Inc.
InventorsBenjamin P. Abbott, Robert Aigner, Julien Gratier, Taeho Kook
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Abstract
Improved coupling coefficients and desirable filter characteristics are exhibited in a SAW filter including an electrode pattern deposited on a piezoelectric substrate bonded directly to an anti-reflective layer, wherein the anti-reflective layer is bonded to a carrier through an adhesive layer such that a preselected thickness of the anti-reflective layer is sufficient for enhancing an acoustic match between the piezoelectric substrate and the adhesive layer.
Claims20
A SAW filter comprising:
- a piezoelectric substrate having first and second opposing surfaces;
- an electrode pattern deposited on the first surface of the piezoelectric substrate;
- an anti-reflective layer directly bonded to the second surface of the piezoelectric substrate;
- a carrier substrate;
- and
- an adhesive layer securing the anti-reflective layer to the carrier substrate, wherein the anti-reflective layer enhances an acoustic match between the piezoelectric substrate and the adhesive layer,
- wherein a thickness of the anti-reflective layer results in a suppression of acoustic reflections, and
- wherein the anti-reflective layer has an acoustic impedance and a velocity that is generally half way between that of the piezoelectric substrate and that of the adhesive layer, thus reducing shear wave reflections.
5 more elements
A SAW filter comprising:
- a piezoelectric substrate having first and second opposing surfaces;
- an electrode pattern deposited on the first surface of the piezoelectric substrate;
- an anti-reflective layer directly bonded to the second surface of the piezoelectric substrate, wherein the anti-reflective layer comprises at least one of Si, Silicon oxide and Aluminium oxide;
- a carrier substrate;
- and
- an adhesive layer securing the anti-reflective layer to the carrier substrate, wherein the anti-reflective layer enhances an acoustic match between the piezoelectric substrate and the adhesive layer.
3 more elements
A SAW filter comprising:
- a piezoelectric substrate having first and second opposing surfaces;
- an electrode pattern deposited on the first surface of the piezoelectric substrate;
- an anti-reflective layer having opposing first and second surfaces, wherein the first surface is bonded to the second surface of the piezoelectric substrate;
- a carrier substrate having a surface thereon for receiving the anti-reflective layer;
- and
- an adhesive material securing the second surface of the anti-reflective layer to the surface of the carrier substrate, wherein a thickness of the anti-reflective layer is sufficient for enhancing an acoustic match between the piezoelectric substrate and the adhesive material,
- wherein a thickness of the anti-reflective layer results in a suppression of acoustic reflections, and
- wherein the anti-reflective layer has an acoustic impedance and a velocity that is generally half way between that of the piezoelectric substrate and that of the adhesive material, thus reducing shear wave reflections.
5 more elements
A SAW filter comprising:
- a piezoelectric substrate;
- a carrier substrate;
- and
- an anti-reflective layer bonded on one side to the piezoelectric substrate and attached on an opposing side to the carrier substrate by applying an adhesive layer therebetween, wherein a thickness of the anti-reflective layer is sufficient for enhancing an acoustic match between the piezoelectric substrate and the adhesive layer,
- wherein the anti-reflective layer has an acoustic impedance and a velocity that is generally half way between that of the piezoelectric substrate and that of the adhesive layer, thus reducing shear wave reflections.
2 more elements
Dependencies are inferred from the claim text.