# US 7,466,064 B2 · Ultrasonic element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,466,064 B2 - Document ID: US7466064B2 - Status: Granted - Kind: B2 - Application number: 11/355,114 - Filed: 2006-02-16 - Published: 2006-08-24 - Granted: 2008-12-16 - Earliest claimed: 2005-02-21 - Assignees: Denso Corporation - Inventors: Makiko Sugiura; Tomoki Itoh - Web page: https://patentgrep.com/patent/US7466064B2 ## CPC - H03H 9/588: {Membranes} - B06B 1/0692: {with a continuous electrode on one side and a plurality of electrodes on the other side} - H03H 3/02: for the manufacture of piezoelectric or electrostrictive resonators or networks (H03H3/08 takes precedence) - H03H 9/02133: {of stress} - H03H 9/172: {Means for mounting on a substrate, i.e. means constituting the material interface confining the waves to a volume} - H03H 9/564: {implemented with thin-film techniques} - H03H 9/583: {comprising a plurality of piezoelectric layers acoustically coupled} - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) - B06B: METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, {e.g.} FOR PERFORMING MECHANICAL WORK IN GENERAL (for particular applications, see the relevant subclasses, e.g. B07B1/40, B23Q17/12, B24B31/06; measurement of mechanical vibrations G01H; in direction finding, locating, distance or velocity measuring G01S; {generating seismic energy G01V1/02}; control of mechanical vibrations in general G05D; sound-producing devices, e.g. bells, sirens, whistles G10K, {e.g. methods or devices for transmitting, conducting, or directing sound in general G10K11/00}; generation of electrical oscillations H03B; electromechanical resonators in general H03H; electromechanical transducers {for communication techniques, e.g. microphones, speakers} H04R) ## Abstract An ultrasonic element has a membrane formed as a thin walled portion of a substrate, on which a piezoelectric vibrator is formed. The piezoelectric vibrator comprises a piezoelectric thin film and metal electrode films, which are formed into a sandwiched structure. The piezoelectric vibrator resonates with the membrane at a predetermined ultrasonic wave-band frequency. A hollow-out pattern is formed in the piezoelectric thin film to divide the piezoelectric vibrator into multiple portions, wherein the hollow-out pattern is formed in such an area corresponding to stress concentrated area which appears in vibrations of the membrane in diametrical directions thereof. The membrane is made to be easily deformed in response to vibration of the piezoelectric vibrator, so that an ultrasound of a higher sound pressure can be emitted. ## Claims ### Claim 1 An ultrasonic element comprising: a membrane formed as a thin walled portion on a substrate; a piezoelectric vibrator formed on the membrane to cover the same, wherein a piezoelectric thin film is sandwiched between metal electrode films, and the piezoelectric vibrator resonates with the membrane at a predetermined ultrasonic wave-band frequency; and a hollow-out pattern partially formed in the piezoelectric thin film to divide the piezoelectric vibrator into multiple portions, wherein the hollow-out pattern is formed in such an area corresponding to stress concentrated area which appears in vibrations of the membrane in diametrical directions thereof. ### Claim 2 (depends on 1) An ultrasonic element according to claim 1, wherein a plane shape of the membrane is formed into a polygon shape; and the stress concentrated area corresponds to a vicinity of a center of the polygon shape and a vicinity of each center of respective edges of the polygon shape. ### Claim 3 (depends on 2) An ultrasonic element according to claim 2, wherein the hollow-out pattern is formed in the piezoelectric thin turn as a circular shape in the vicinity of the center of the polygon shaped membrane. ### Claim 4 (depends on 2) An ultrasonic element according to claim 2, wherein the hollow-out pattern is formed in the piezoelectric thin film as such a polygon shape, which has the same number of edges to that of the edges of the polygon shaped membrane, in the vicinity of the center of the polygon shaped membrane. ### Claim 5 (depends on 2) An ultrasonic element according to claim 2, wherein the hollow-out pattern is formed in the piezoelectric thin film as an actiniform pattern, such that the hollow-out pattern connects the vicinity of the center of the polygon shape with the vicinity of each center of the respective edges. ### Claim 6 (depends on 2) An ultrasonic element according to claim 2, wherein the hollow-out pattern is formed in the piezoelectric thin film as an actiniform pattern, such that the hollow-out pattern connects the vicinity of the center of the polygon shape with the vicinity of each of the respective corners. ### Claim 7 (depends on 2) An ultrasonic element according to claim 2, wherein the plane shape of the membrane is formed into a square shape. ### Claim 8 (depends on 1) An ultrasonic element according to claim 1, wherein a plane shape of the membrane is formed into a circular shape, and the stress concentrated area corresponds to a vicinity of a center of the circular shape. ### Claim 9 (depends on 8) An ultrasonic element according to claim 8, wherein the hollow-out pattern is formed in the piezoelectric thin film as a circular shape in the vicinity of the center of the circular shaped membrane. ### Claim 10 (depends on 1) An ultrasonic element according to claim 1, wherein the ultrasonic element is used as an ultrasound emitting element. ### Claim 11 (depends on 10) An ultrasonic element according to claim 10, wherein an ultrasound receiving element is formed in the same substrate to that of the ultrasound emitting element, but at a different position from the ultrasound emitting element. ### Claim 12 An ultrasonic element comprising: a membrane formed as a thin walled portion on a substrate; a piezoelectric vibrator formed on the membrane to cover the same, wherein a piezoelectric thin film is sandwiched between metal electrode films, and the piezoelectric vibrator resonates with the membrane at a predetermined ultrasonic wave-band frequency; and a shallow groove pattern partially formed in the piezoelectric thin film not to completely separate the piezoelectric thin film into but to define multiple portions of the piezoelectric vibrator, wherein the shallow groove pattern is formed in such an area corresponding to stress concentrated area which appears m vibrations of the membrane in diametrical directions thereof. ### Claim 13 (depends on 12) An ultrasonic element according to claim 12, wherein a plane shape of the membrane is formed into a polygon shape, and the stress concentrated area corresponds to a vicinity of a center of the polygon shape and a vicinity of each center of respective edges of the polygon shape. ### Claim 14 (depends on 13) An ultrasonic element according to claim 13, wherein the shallow groove pattern is formed in the piezoelectric thin film as a circular shape in the vicinity of the center of the polygon shaped membrane. ### Claim 15 (depends on 13) An ultrasonic element according to claim 13, wherein the shallow groove pattern is formed in the piezoelectric thin film as such a polygon shape, which has the same number of edges to that of the edges of the polygon shaped membrane, in the vicinity of the center of the polygon shaped membrane. ### Claim 16 (depends on 13) An ultrasonic element according to claim 13, wherein the shallow groove pattern is formed in the piezoelectric thin film as an actiniform pattern, such that the shallow groove pattern connects the vicinity of the center of the polygon shape with the vicinity of each center of the respective edges. ### Claim 17 (depends on 13) An ultrasonic element according to claim 13, wherein the shallow groove pattern is formed in the piezoelectric thin film as an actiniform pattern, such that the shallow groove pattern connects the vicinity of the center of the polygon shape with the vicinity of each of the respective corners. ### Claim 18 (depends on 13) An ultrasonic element according to claim 13, wherein the plane shape of the membrane is formed into a square shape. ### Claim 19 (depends on 12) An ultrasonic element according to claim 12, wherein a plane shape of the membrane is formed into a circular shape, and the stress concentrated area corresponds to a vicinity of a center of the circular shape. ### Claim 20 (depends on 19) An ultrasonic element according to claim 19, wherein the shallow groove pattern is formed in the piezoelectric thin film as a circular shape in the vicinity of the center of the circular shaped membrane. ### Claim 21 (depends on 12) An ultrasonic element according to claim 12, wherein the ultrasonic element is used as an ultrasound emitting element. ### Claim 22 (depends on 21) An ultrasonic element according to claim 21, wherein an ultrasound receiving element is formed in the same substrate to that of the ultrasound emitting element, but at a different position from the ultrasound emitting element.