Dual frequency ultrasound transducer

Patent metadata

Field	Value
Publication number	US-11774589-B2
Application number	US-202117522293-A
Country	US
Kind code	B2
Filing date	Nov 9, 2021
Priority date	May 3, 2018
Publication date	Oct 3, 2023
Grant date	Oct 3, 2023

Abstract

A dual frequency ultrasound transducer includes a high frequency (HF) transducer and a low frequency (LF) transducer that is positioned behind the high frequency transducer. An intermediate layer is positioned between the low frequency transducer and the high frequency transducer to absorb high frequency ultrasound signals. An alignment feature on the low frequency transducer is positioned with respect to a fiducial that is marked at a known position with respect to high frequency transducer elements of the HF transducer to align low frequency transducer elements of the LF transducer with the HF transducer elements.

First claim

We claim:

1. A method of manufacturing a dual frequency transducer comprising:
providing a high frequency (HF) transducer having a first sheet of piezoelectric material including HF transducer elements, one or more matching layers, and a HF frame;
securing a surface of the first sheet of piezoelectric material to a support frame, the support frame including an epoxy material;
forming at least one alignment post in the epoxy material;
marking the at least one alignment post with one or more fiducials;
positioning, on a first side of the HF transducer elements, an intermediate layer that is configured to absorb HF ultrasound signals, the intermediate layer including at least one slot configured to engage with the at least one alignment post;
aligning, with the one or more fiducials, a low frequency (LF) transducer including:
one or more tabs with an alignment feature that aligns the LF transducer with the one or more fiducials;
a second sheet of piezoelectric material including LF transducer elements; and
one or more matching layers; and

securing the one or more matching layers to the intermediate layer.

2. The method of claim 1 , wherein the alignment feature comprises a hole on an alignment tab that is at a known position with respect to the LF transducer elements of the LF transducer.

3. The method of claim 1 , wherein the intermediate layer is made of silicone powder-doped epoxy.

4. The method of claim 3 , wherein a surface of the support frame is filled with an epoxy having a recess into which a portion of the intermediate layer is fitted.

5. The method of claim 4 , wherein the intermediate layer is adhered to the recess with the same epoxy in which the recess is formed.

6. The method of claim 1 , wherein the intermediate layer is larger than an area of the HF transducer elements in the piezoelectric material of the HF transducer.

7. The method of claim 1 , wherein the intermediate layer includes at least one fiducial marked at a known position with respect to the HF transducer elements, and wherein the alignment feature on the LF transducer is aligned with the at least one fiducial on the intermediate layer.

8. The method of claim 1 , wherein at least one of the tabs includes a hole to place over the one or more fiducials on the HF transducer.

9. The method of claim 1 , wherein the one or more tabs in the LF transducer are incorporated into the one or more matching layers of the LF transducer.

10. The method of claim 1 , wherein the first sheet of piezoelectric material further comprises an outer perimeter with an edge, and wherein the support frame surrounds the outer perimeter of the first sheet of piezoelectric material and is spaced from the edge of the outer perimeter such that kerf cuts that define individual transducer elements in the first sheet of piezoelectric material extend across a full width of the first sheet of piezoelectric material.

11. A method of manufacturing a dual frequency transducer comprising:
providing a high frequency (HF) transducer comprising a sheet of piezoelectric material including a number of HF transducer elements;
providing a backing material that is constructed to absorb HF ultrasound signals and pass low frequency (LF) ultrasound signals;
providing one or more fiducials marked on a first side of the HF transducer elements at a known position with respect to the HF transducer elements; and
providing an LF transducer including a number of LF transducer elements including one or more alignment tabs that are positioned using the one or more fiducials to align the LF transducer elements with the HF transducer elements.

12. The method of claim 11 , further comprising incorporating the one or more alignment tabs in the LF transducer into a matching layer of the LF transducer.

13. The method of claim 12 , further comprising securing the one or more alignment tabs in an epoxy layer that forms the matching layer.

14. The method of claim 13 , further comprising aligning the LF transducer elements with respect to the HF transducer elements by placing a hole in the one or more alignment tabs over the one or more fiducials.

15. A method of manufacturing a dual frequency transducer comprising:
providing a high frequency (HF) transducer including
a first sheet of piezoelectric material including a number of HF transducer elements,
one or more matching layers, and
a support frame on a back side of the piezoelectric material configured to support one or more flex circuits with first signal traces that connect to the HF transducer elements;

providing one or more fiducials marked at known positions with respect to the HF transducer elements;
providing an intermediate layer that is configured to absorb HF ultrasound signals and positioned on a first side of the HF transducer elements; and
providing a low frequency (LF) transducer including
a second sheet of piezoelectric material including a number of LF transducer elements,
one or more matching layers, and
a flex circuit with second signal traces that connect to the LF transducer elements, wherein the LF transducer includes one or more tabs with an alignment feature that aligns the LF transducer with a fiducial.

16. The method of claim 15 , wherein the alignment feature comprises a hole on an alignment tab that is at a known position with respect to the LF transducer elements of the LF transducer.

17. The method of claim 15 , wherein the intermediate layer is made of silicone powder-doped epoxy.

18. The method of claim 17 , wherein the support frame has a surface and wherein the surface of the support frame is filled with an epoxy having a recess into which a portion of the intermediate layer is fitted.

19. The method of claim 18 , wherein the intermediate layer is adhered to the recess with the same epoxy in which the recess is formed.

20. The method of claim 15 , wherein the first sheet of piezoelectric material further comprises an outer perimeter with an edge, and wherein the support frame surrounds the outer perimeter of the first sheet of piezoelectric material and is spaced from the edge of the outer perimeter such that kerf cuts that define individual transducer elements in the first sheet of piezoelectric material extend across a full width of the first sheet of piezoelectric material.

Assignees

• Fujifilm Sonosite Inc

Inventors

• Pang Guofeng
• Ivanytskyy Oleg
• Amini Hossein
• Kolaja Robert

Classifications

• G01S15/8952 Primary

  using discrete, multiple frequencies · CPC title

• G01S15/8915

  using a transducer array · CPC title

• G01S15/8956

  using frequencies at or above 20 MHz · CPC title

• G01S15/8979

  Combined Doppler and pulse-echo imaging systems · CPC title

• G01S7/52079 Primary

  Constructional features (constructional features of transducers B06B; mounting transducers G10K11/00; constructional features of ultrasonic medical diagnostic devices A61B8/44) · CPC title