Ultrasonic transducer array

• US 5,311,095 A
• Filed: 05/14/1992
• Issued: 05/10/1994
• Est. Priority Date: 05/14/1992
• Status: Expired due to Term

• Current Assignee: Duke University
• Original Assignee: Duke University
• Inventors: Poulin, Thomas R., Roeder, Paul J., Smith, Stephen W., von Ramm, Olaf T.
• Primary Examiner(s): Budd, Mark O.
• Application Number:
  US07/883,006
• Time in Patent Office: 726 Days
• Field of Search: 310/322, 310/326, 310/327, 310/348, 310/334-337, 367/157, 367/155, 367/153, 367/140, 367/138, 128/660.01, 128/660.03, 128/660.07
• US Class Current: 310/334
• CPC Class Codes: B06B 1/064 with multiple active layers

Abstract

Disclosed is a ultrasonic transducer array comprising a ceramic connector having an array of connector pads, a mismatching layer of electrically conducting material connected to the upper surface of the ceramic connector, a piezoelectric transducer chip connected to the mismatching layer, separation means for dividing the piezoelectric chip into a plurality of transducer elements positioned in a two-dimensional array, wherein each one of the plurality of transducer elements is selectively connected to a corresponding one of the connector pads. Also disclosed in a two-dimensional ultrasound transducer array and transducer array for ultrasound imaging.

Claims

1. A two-dimensional array ultrasonic transducer for ultrasonic imaging comprising:

a ceramic connector having an upper surface, a lower surface and an array of connector pads formed in said ceramic connector for electrically connecting said upper surface to said lower surface;

a mismatching layer of electrically conducting material connected to said upper surface of said ceramic connector;

a piezoelectric transducer chip connected to said mismatching layer;

a matching layer of electrically conducting material having an upper surface and a lower surface wherein said lower surface of said matching layer connected to said piezoelectric chip;

slot means extending downward from said upper surface of said matching layer into said ceramic connector for dividing said matching layer, piezoelectric chip, mismatching layer and ceramic connector into a plurality of transducer elements of from about 0.1 mm to about 1 mm in width, from about 0.1 mm to about 20 mm in length and from about 0.1 mm to about 1 mm in height, said transducer elements being positioned in a two-dimensional array wherein each one of said plurality of transducer elements is electrically connected to a corresponding one of said connector pads;

an uppermost layer of electrically conducting foil connected to said upper surface of said matching layer;

redistribution means for redistributing the position of electrical connections for said array of transducer elements to increase the distance between electrical connections to a distance greater than that between individual connector pads of said array of connector pads; and

voltage source means connected to said redistribution means for electrically exciting said array of transducer elements to produce an ultrasonic pulse of from about 1 to about 10 MHz.

2. The two-dimensional array ultrasonic transducer of claim 1 wherein said slot means comprises a groove.

3. The two-dimensional array ultrasonic transducer of claim 1 wherein said slot means comprises a plurality of grooves.

4. The two-dimensional array ultrasonic transducer of claim 1 wherein said slot means comprises a plurality of grooves filled with materials selected from the group consisting of glass balloons and polymer foam.

5. The two-dimensional array ultrasonic transducer of claim 1 wherein said array of transducer elements is a rectangular array of transducer elements and wherein said transducer element array is configured by selecting elements from said rectangular array of transducer elements.

6. The two-dimensional array ultrasonic transducer of claim 1 further comprising a stand-off to improve the contact of the said ultrasonic transducer with the subject of the irradiation.

7. The two-dimensional array ultrasonic transducer of claim 1 wherein said matching and said mismatching layers are silver epoxy.

8. The two-dimensional array ultrasonic transducer of claim 1 wherein said redistribution means comprises:

a first ceramic redistribution layer having conducting strips electrically connected to said connector pads and extending in a first direction, said first redistribution layer having an upper surface and a lower surface wherein said upper surface of said first redistribution layer is adjacent said lower surface of said ceramic connector;

a first conductive layer having an upper surface and a lower surface wherein said upper surface of said first conductive layer is adjacent said lower surface of said first redistribution layer;

a second ceramic redistribution layer having conducting strips extending in a second direction transverse to said first direction, said second redistribution layer having an upper surface and a lower surface wherein said upper surface of said second redistribution layer is adjacent said lower surface of said first conductive layer;

vias formed in said first conductive layer to electrically connect said first redistribution layer to said second redistribution layer; and

a second conductive layer having an upper surface and a lower surface wherein said upper surface of said second conductive layer is adjacent said lower surface of said second redistribution layer, said second conductive layer having vias formed therein to provide output pads for said two-dimensional array ultrasonic transducer.

9. The two-dimensional array ultrasonic transducer of claim 1 further comprising amplifier means for receiving electrical signals from said array of transducer elements.

10. The two-dimensional array ultrasonic transducer of claim 1 further comprising a handle.

11. The two dimensional array ultrasonic transducer of claim 1 wherein said piezoelectric chip is a PZT chip.

12. A two dimensional array ultrasonic transducer of claim 1, further comprising an integrated circuit mounted on said ceramic connector and in electrical connection with said transducer elements.

13. The two dimensional array ultrasonic transducer of claim 12 wherein said integrated circuit is comprised of a plurality of amplifiers.

14. An ultrasonic transducer array comprising:

a ceramic connector having an upper surface, a lower surface and an array of connector pads formed in said ceramic connector for electrically connecting said upper surface to said lower surface;

a mismatching layer of electrically conducting material connected to said upper surface of said ceramic connector;

a piezoelectric transducer chip having an upper surface and a lower surface, wherein the lower surface of said piezoelectric chip is connected to said mismatching layer;

separation means for dividing said piezoelectric chip into a plurality of transducer elements, wherein each one of said plurality of transducer elements is selectively connected to a corresponding one of said connector pads;

a first ceramic redistribution layer having conducting strips electrically connected to said connector pads and extending in a first direction, said first redistribution layer having an upper surface and a lower surface wherein said upper surface of said first redistribution layer is adjacent said lower surface of said ceramic connector;

a first conductive layer having an upper surface and a lower surface wherein said upper surface of said first conductive layer is adjacent said lower surface of said first redistribution layer;

a second ceramic redistribution layer having conducting strips extending in a second direction transverse to said first direction, said second redistribution layer having an upper surface and a lower surface wherein said upper surface of said second redistribution layer is adjacent said lower surface of said first conductive layer;

vias formed in said first conductive layer to electrically connect said first redistribution layer to said second redistribution layer; and

a second conductive layer having an upper surface and a lower surface wherein said upper surface of said second conductive layer is adjacent said lower surface of said second redistribution layer, said second conductive layer having vias formed therein to provide output pads for said two-dimensional array ultrasonic transducer.

15. A two-dimensional array ultrasonic transducer comprising:

a ceramic connector having an upper surface, a lower surface and an array of connector pads formed in said ceramic connector for electrically connecting said upper surface to said lower surface;

a mismatching layer of electrically conducting material connected to said upper surface of said ceramic connector;

a piezoelectric transducer chip having an upper surface and a lower surface wherein the said lower surface of said piezoelectric chip is connected to said mismatching layer;

slot means extending downward from said upper surface of said piezoelectric chip into said ceramic connector for dividing said piezoelectric chip, mismatching layer and ceramic connector into a plurality of transducer elements positioned in a two-dimensional array, wherein each one of said plurality of transducer elements is electrically connected to a corresponding one of said connector pads;

an uppermost layer of electrically conducting foil connected to said upper surface of said piezoelectric chip;

a first ceramic redistribution layer having conducting strips electrically connected to said connector pads and extending in a first direction, said first redistribution layer having an upper surface and a lower surface wherein said upper surface of said first redistribution layer is adjacent said lower surface of said ceramic connector;

a first conductive layer having an upper surface and a lower surface wherein said upper surface of said first conductive layer is adjacent said lower surface of said first redistribution layer;

a second ceramic redistribution layer having conducting strips extending in a second direction transverse to said first direction, said second redistribution layer having an upper surface and a lower surface wherein said upper surface of said second redistribution layer is adjacent said lower surface of said first conductive layer;

vias formed in said first conductive layer to electrically connect said first redistribution layer to said second redistribution layer;

a second conductive layer having an upper surface and a lower surface wherein said upper surface of said second conductive layer is adjacent said lower surface of said second redistribution layer, said second conductive layer having vias formed therein to provide output pads for said two-dimensional array ultrasonic transducer.