Medical diagnostic ultrasound transducer and method of manufacture

• US 6,489,706 B2
• Filed: 11/13/1998
• Issued: 12/03/2002
• Est. Priority Date: 11/13/1998
• Status: Expired due to Fees

• Current Assignee: Acuson Corporation (Siemens AG)
• Original Assignee: Acuson Corporation (Siemens AG)
• Inventors: Spigelmyer, Matthew T., Edmiston, Rick L., Hossack, John A., Sliwa, John W. Jr., Mohr, John P. III, Marian, Vaughn R. Jr.
• Primary Examiner(s): Dougherty, Thomas M.
• Assistant Examiner(s): MEDLEY, PETER M
• Application Number:
  US09/191,653
• Publication Number:
  US 20010015592A1
• Time in Patent Office: 1,481 Days
• Field of Search: 310/334, 310/335, 310/336, 310/337, 600/459
• US Class Current: 310/334
• CPC Class Codes: B06B 1/0607 using multiple elements B06B1/064 and B06B1/0688 take precedence
• CPC Class Codes: B06B 1/0622 on one surface
• CPC Class Codes: B06B 2201/76 Medical, dental

Abstract

A plurality of piezomaterial bodies, such as panels or slices, are merged together to form a larger piezomaterial body. For example, a 0.75×22 cm polycrystalline piezomaterial body is formed, where the distances are along lateral or footprint dimensions. The thickness of the piezomaterial body is substantially less than either of the distances along first and second lateral dimensions that define the footprint. Preferably, each piezomaterial body has a panel shape, and a plurality of panels are merged to form a large multi-panel.

Claims

1. A medical ultrasound transducer comprising:

a first piezomaterial body having a first thickness that is substantially less than either of first and second distances along first and second lateral dimensions, respectively, the first and second distances defining a first area;

a second piezomaterial body having a second thickness that is substantially less than either of third and fourth distances along the first and second lateral dimensions, respectively, the third and fourth distances defining a second area; and

an acoustically attenuative backing material adjacent the first and second piezomaterial bodies;

wherein a first lateral edge of the first piezomaterial body is adjacent a second lateral edge of the second piezomaterial body, a lateral area of the adjacent first and second adjacent piezomaterial bodies greater than either of the first and second areas, the first and second peizomaterial bodies forming a one dimensional array of elements, the lateral area being rectangular.

2. The transducer of claim 1 wherein the lateral area of the first and second adjacent piezomaterial bodies is substantially the same as a sum of the first and second areas.

3. The transducer of claim 1 wherein the first and second piezomaterial bodies comprise monocrystalline piezomaterial and the lateral area of the first and second adjacent piezomaterial bodies is greater than 2 cm².

4. The transducer of claim 1 wherein a lateral dimension of the combined bodies is greater than 15 cm and the bodies comprise polycrystalline piezomaterial.

5. The transducer of claim 1 wherein at least the first piezomaterial body comprises a panel.

6. The transducer of claim 1 wherein at least the first piezomaterial body comprises polycrystalline piezomaterial.

7. The transducer of claim 1 wherein at least the first piezomaterial body comprises monocrystalline piezomaterial.

8. The transducer of claim 1 wherein the first and second lateral edges are divergent.

9. The transducer of claim 1 wherein at least the first piezomaterial body comprises a composited body.

10. The transducer of claim 9 wherein kerfs in the first piezomaterial body have a lesser width than a distance between the first and second lateral edges.

11. The transducer of claim 9 wherein a kerf in the first piezomaterial body is associated with two substantially parallel edges, and the first and second lateral edges are divergent.

12. The transducer of claim 9 wherein kerfs in the first piezomaterial body are parallel to kerfs in the second piezomaterial body.

13. The transducer of claim 9 wherein kerfs in the first piezomaterial body are at an angle between 0 and 90 degrees to kerfs in the second piezomaterial body.

14. The transducer of claim 1 further comprising at least a third piezomaterial body.

15. The transducer of claim 14 wherein the first, second and at least third piezomaterial bodies are aligned in an N by 1 configuration in the lateral dimensions, where N is the number of piezomaterial bodies.

16. The transducer of claim 14 wherein the first, second and at least third piezomaterial bodies are aligned in an N by M configuration in the lateral dimensions, where N and M are numbers of piezomaterial bodies, where N and M are greater than one and the piezomaterial bodies comprise two adjacent single one dimensional arrays of elements which define a two-dimensional array.

17. The transducer of claim 14 wherein the at least third piezomaterial body is stacked on at least one of the first and second piezomaterial bodies, the at least one first or second piezomaterial body and the at least third piezomaterial body comprising a two layer body.

18. The transducer of claim 1 wherein at least the first thickness varies as a function of at least one of the first and second lateral dimensions.

19. The transducer of claim 1 wherein the first and second piezomaterial bodies have at least one common value of thickness at least one location.

20. The transducer of claim 1 wherein the first piezomaterial body comprises a composition different than the second piezomaterial body.

21. The transducer of claim 1 wherein the first piezomaterial body is associated with a different degree of poling than the second piezomaterial body.

22. The transducer of claim 1 wherein at least two separate electrodes connect to the first piezomaterial body.

23. The transducer of claim 1 wherein at least two electrodes contact at least two respective electrically addressable piezoelements in said first body.

24. The transducer of claim 1 wherein the transducer comprises a type selected from the group consisting of:

linear, curved linear, and two-dimensional arrays.

25. The transducer of claim 1 wherein the first piezomaterial body comprises a lateral shape selected from the group consisting of:

square, rectangular, multi-sided, and combinations thereof.

26. The transducer of claim 1 wherein at least one piezomaterial body has enhanced harmonic performance provided by at least one of variable thickness and monocrystalline piezomaterial.

27. A medical ultrasound transducer comprising:

a multi-panel of piezomaterial comprising;

at least first and second abutted panels comprising a one dimensional array of elements, the at least first and second abutted panels having a combined rectangular area, each of the first and second abutted panels associated with two or more elements of the one dimensional array; and

a backing material side and a matching layer side, the backing material side comprising first and second abutted panel sides of the first and second panels, respectively, the matching layer side comprising third and fourth abutted panel sides of the first and second panels, respectively;

an acoustically attenuative backing material adjacent the backing material side; and

at least one matching layer adjacent the matching layer side.

28. The transducer of claim 27 wherein:

the first panel comprises a first thickness that is substantially less than either of first and second distances along first and second lateral dimensions, respectively; and

the second panel comprises a second thickness that is substantially less than either of third and fourth distances along the first and second lateral dimensions, respectively.

29. The transducer of claim 27 wherein at least the first panel comprises moncrystalline piezomaterial.

30. The transducer of claim 27 wherein the multi-panel comprises polycrystalline piezomaterial and a lateral dimension of the multi-panel is greater than 15 cm.

31. The transducer of claim 30 wherein a second lateral dimension is less than 1 cm.

32. The transducer of claim 27 wherein at least the first panel comprises moncrystalline piezomaterial.

33. The transducer of claim 27 wherein a kerf in the first panel have a lesser width than a distance between the first and second panels.

34. The transducer of claim 27 wherein a kerf in the first panel is associated with two substantially parallel edges, and abutting edges of the first and second panels are divergent.

35. The transducer of claim 27 wherein the first panel comprises a composition different than the second panel.

36. The transducer of claim 27 wherein at least two separate electrodes connect to the first panel and at least two electrodes connect to the second panel.

37. The transducer of claim 27 wherein at least two electrodes contact at least two respective piezoelements in said first panel.

38. The transducer of claim 27 wherein at least the first panel has enhanced harmonic performance provided by one of variable thickness and monocrystalline piezomaterial.

39. A medical ultrasound transducer comprising;

an acoustically attenuative backing material;

at least one matching layer; and

a monocrystalline piezomaterial element comprising at least 2 cm² area on a matching layer side;

wherein the piezomaterial element is laminated between the backing material and the at least one matching layer.

40. The transducer of claim 39 wherein the piezomaterial element comprises at least first and second abutted panels.

41. The transducer of claim 39 wherein:

the piezomaterial element comprises at least first and second piezomaterial bodies;

the first piezomaterial body comprises a first thickness that is substantially less than either of first and second distances along first and second lateral dimensions, respectively, the first and second distances defining a first area that is less than or equal to 1 cm²; and

the second piezomaterial body comprises a second thickness that is substantially less than either of third and fourth distances along the first and second lateral dimensions, respectively, the third and fourth distances defining a second area that is less than or equal to 1 cm².

42. A method of manufacturing a medical ultrasound transducer, the method comprising the steps of:

(a) providing at least first and second panels of piezomaterial;

(b) abutting the at least first and second panels of piezomaterial, the abutted at least first and second panels comprising a laterally extended multi-panel of a one dimensional array of elements, the laterally extended multi-panel being rectangular; and

(c) mating the multi-panel with an acoustically attenuative backing material and at least one matching layer.

43. The method of claim 42 further comprising step (d) of compositing at least one of the first and second panels prior to step (b).

44. The method of claim 42 wherein step (b) comprises abutting the at least first and second panels so that a matching layer side area of the multi-panel is greater than either of first and second matching layer side areas of the first and second panels, respectively.

45. The method of claim 42 further comprising step (d) of compositing the first and second panels after step (b).

46. The method of claim 42 wherein any one of steps (a) and (b) are performed before step (c).

47. The method of claim 46 further comprising step (d) of metalizing the multi-panel before step (c) is completed.

48. The method of claim 46:

further comprising step (d) of attaching the at least first and second panels to a matching layer; and

wherein step (c) comprises mating the multi-panel and the matching layer to at least the acoustically attenuative backing material.

49. The method of claim 48 wherein the at least first and second panels are bonded to the matching layer.

50. The method of claim 42 wherein step (b) is performed as part of step (c).

51. The method of claim 50 wherein step (b) comprises placing the at least first and second panels on a carrier tape before step (c).

52. The method of claim 43 wherein step (b) comprises abutting the at least first and second composited panels so that kerfs on the first panel are at an angle between 0 and 90 degrees to kerfs on the second panel.

53. The method of claim 43 wherein step (b) comprises abutting the at least first and second composited panels so that kerfs on the first panel are parallel to kerfs on the second panel.

54. The method of claim 42 wherein step (c) comprises providing the multipanel comprising as a monocrystalline piezomaterial and comprising a matching layer surface area of at least 2 cm².

55. The method of claim 42 wherein step (a) comprises providing the at least first and second panels as monocrystalline piezomaterial.

56. The method of claim 42 further comprising step (e) of providing at least two electrodes on the first panel and at least two electrodes on the second panel.

57. The method of claim 42 wherein the ultrasound transducer has enhanced harmonic performance contributed by at least one of monocrystalline PZT and variables thickness in at least one piezomaterial panel.

58. The method of claim 42 wherein at least one panel comprises at least two electrically addressable piezoelements.

59. A medical ultrasound transducer comprising:

a first piezomaterial body having a first thickness that is substantially less than either of first and second distances along first and second lateral dimensions, respectively, the first and second distances defining a first area;

a second piezomaterial body having a second thickness that is substantially less than either of third and fourth distances along the first and second lateral dimensions, respectively, the third and fourth distances defining a second area;

an acoustically attenuative backing material adjacent the first and second piezomaterial bodies; and

wherein a first lateral edge of the first piezomaterial body is adjacent a second lateral edge of the second piezomaterial body, a lateral area of the adjacent first and second adjacent piezomaterial bodies greater than either of the first and second areas, the first and second peizomaterial bodies forming an array absent intersection with another array.

60. A medical ultrasound transducer comprising:

a first monocrystalline piezomaterial body having a first thickness that is substantially less than either of first and second distances along first and second lateral dimensions, respectively, the first and second distances defining a first area;

a second monocrystalline piezomaterial body having a second thickness that is substantially less than either of third and fourth distances along the first and second lateral dimensions, respectively, the third and fourth distances defining a second area; and

an acoustically attenuative backing material adjacent the first and second piezomaterial bodies;

wherein a first lateral edge of the first piezomaterial body is adjacent a second lateral edge of the second piezomaterial body, a lateral area of the adjacent first and second adjacent piezomaterial bodies greater than either of the first and second areas and greater than 2 cm^2.