High frequency piezoelectric crystal composites, devices, and methods for manufacturing the same
AssigneeH.C. Materials Corporation
InventorsPengdi Han, Jian Tian, Kevin Meneou, Brandon Stone
Life of this patent
Estimating the term…
Abstract
The present invention generally relates to high frequency piezoelectric crystal composites, devices, and method for manufacturing the same. In adaptive embodiments an improved imaging device, particularly a medical imaging device or a distance imaging device, for high frequency (>20 MHz) applications involving an imaging transducer assembly is coupled to a signal imagery processor. Additionally, the proposed invention presents a system for photolithography based micro-machined piezoelectric crystal composites and their uses resulting in improved performance parameters.
Claims24
A method for fabricating a high frequency imagery transducer for an imagery device, said imagery transducer including one or more composite crystal elements, comprising the steps of:
- providing an oriented single crystal plate of a piezoelectric material having a thickness electromechanical coupling factor kt in the range of approximately 0.65-0.90;
- etching said oriented single crystal plate with photolithography based micromachining to form a plurality of hybrid piezoelectric structures separated by a plurality of kerfs;
- wherein said photolithography based micromachining further includes the steps of:
- (a) forming a hard metal mask over portions of said plate where said plurality of hybrid piezoelectric structures are to be formed separated by said plurality of kerfs;
- (b) said kerfs including at least one kerf direction having a range of approximately 30 to 35° degrees from a noted orientation direction for said single crystal plate operative to minimize a clamping effect according to the following formula:
- d′31=d31*Cos(θ)*Cos(θ)+d32*Sin(θ)*Sin(θ);
- (c) conducting at least one of a step of reactive-ion etching (RIE) and deep reactive ion etching (DRIE);
- (i) said hybrid piezoelectric structures having a vertical etching profile of at least 85°;
- filling said kerfs with a polymeric material to form a unitary assembly;
- conducting a fine mechanical finishing step of said unitary assembly;
- coating electrodes on said unitary assembly;
- and
- assembling said unitary assembly with a backing operative to form said imagery transducer for said imagery device.
An imaging device configured to operatively include a high frequency transducer assembly;
- said imaging device comprising:
- at least one said transducer assembly coupled to an imaging array and operative to generate an image signal;
- at least one communication pathway from said transducer assembly to an operative processer and imaging system effective to receive said image signal;
- said transducer assembly includes one or more composite crystal elements, in an oriented single crystal plate of a piezoelectric material having a thickness electromechanical coupling factor kt in the range of approximately 0.65-0.90, wherein each transducer assembly is in a configuration selected from a group of configurations consisting of:
- a hexagonal hybrid 1-3 configuration, a parallelogram hybrid 1-3 configuration and a hybrid 2-2/1-3 configuration.
Dependencies are inferred from the claim text.