# US 4,398,325 A · Process for producing ultrasonic transducers having complex shapes

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- Number: US 4,398,325 A
- Document ID: US4398325A
- Status: Granted
- Kind: A
- Application number: 06/272,095
- Filed: 1981-06-10
- Granted: 1983-08-16
- Earliest claimed: 1980-06-25
- Assignees: Commissariat a l'Energie Atomique
- Inventors: Bernard Piaget; Jean-Francois Piquard
- Web page: https://patentgrep.com/patent/US4398325A

## CPC

- B06B 1/0622: {on one surface}
- G10K 11/32: characterised by the shape of the source
- Y10T 29/42: Piezoelectric device making
- 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)
- G10K: SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Process for producing complex ultrasonic transducers comprising cutting out a piezoelectric ceramic block along lines which are parallel to one another by means of at least two rows of channels making it possible to produce elementary transducers and selecting the cut elements so as to obtain the desired complex transducer shape, wherein the selected elements are electrically interconnected by one of their faces by means of a conductive deposit and the other face of said elements is raised to reference potential. Application to the production of ring grating or annular transducers.

## Claims

### Claim 1

A process for producing complex ultrasonic transducers comprising the steps of:
glueing by means of a conductive glue a pizoelectric ceramic block to a conductive support which conductive support is connected to a reference potential;
cutting at least two rows of channels into said ceramic block each row of channels being cut along lines which are parallel to one another such that the channels of each row intersect the channels of at least another row to produce elementary transducers and whereby the entire thickness of the ceramic block is cut through in order to mechanically insulate each produced elementary transducer;
selecting from among the produced elementary transducers obtained by cutting in order to obtain a desired complex transducer shape;
electrically interconnecting the selected elements by one of their faces by means of a conductive deposit; and
raising the other face of said elements to a reference potential.

### Claim 2 (depends on 1)

The process according to claim 1 wherein said complex ultrasonic transducers are annular ultrasonic transducers.

### Claim 3 (depends on 1)

A process according to claim 1, wherein the two rows of channels are at an angle of 90.degree. from one another, the elementary transducers having a square shape.

### Claim 4 (depends on 2)

A production process according to claim 2, wherein a third row of channels is formed in the ceramic block which is at an angle of 45.degree. with the two other rows of channels, thus making it possible to produce elementary transducers having a triangular shape.

### Claim 5 (depends on 1)

A production process according to claim 1, wherein the channel space between two consecutive elements is filled by means of a resin having a high acoustic impedance.

### Claim 6 (depends on 1)

A production process according to claim 1, wherein the conductive deposit is deposited in the form of a strip.

### Claim 7 (depends on 1)

A production process according to claim 1, wherein the conductive deposit is deposited in the form of short lines.

### Claim 8 (depends on 1)

A production process according to claim 1, wherein the conductive deposit is produced by masking.

### Claim 9 (depends on 1)

A production process according to claim 1, wherein the conductive deposit is obtained by vacuum metallization.

### Claim 10 (depends on 1)

A production process according to claim 1, wherein the conductive deposit is obtained by means of a silver based varnish.