Methods for manufacturing ultrasound transducers and other components

Patent metadata

Field	Value
Publication number	US-2018240960-A1
Application number	US-201815900064-A
Country	US
Kind code	A1
Filing date	Feb 20, 2018
Priority date	Sep 18, 2008
Publication date	Aug 23, 2018
Grant date	—

Abstract

The disclosed technology features methods for the manufacture of electrical components such as ultrasound transducers. In particular, the disclosed technology provides methods of patterning electrodes, e.g. in the connection of an ultrasound transducer to an electrical circuit; methods of depositing metal on surfaces; and methods of making integrated matching layers for an ultrasound transducer. The disclosed technology also features ultrasound transducers produced by the methods described herein.

First claim

1 . A method for producing electrodes in a pattern, said method comprising the steps of:
(a) providing an electrical component comprising a first plurality of electrodes; (b) placing a connector comprising a second plurality of electrodes in proximity to the electrical component; (c) depositing a composite dielectric material comprising a matrix material and a particulate material on the first plurality of electrodes and the second plurality of electrodes, wherein the matrix material is laser ablated at a lower fluence than the particulate material; (d) laser ablating at least a portion of the composite dielectric material to remove matrix material and increase the surface area of the composite dielectric material; laser ablating the composite dielectric material to expose the first plurality of electrodes and the second plurality of electrodes; and laser ablating a trench in the composite dielectric material from each of the first plurality of electrodes to a corresponding electrode of the second plurality; (e) depositing a conductive metal on areas ablated in step (d); (f) depositing a resist on the conductive metal, wherein the resist is thicker over the first plurality of electrodes, the second plurality of electrodes, and the trenches compared to other ablated areas; and (g) removing a portion of the resist to expose a portion of the conductive metal in a negative pattern and etching the exposed portion ofthe conductive metal to produce the electrodes in the pattern.

2 . The method of claim 1 , further comprising (h) laser ablating the areas of etched conductive metal to remove at least a portion of the composite dielectric material therein.

3 . The method of claim 2 , wherein in step (h) substantially all of the composite dielectric material and a portion of the component lying under the areas of etched conductive metal are ablated.

4 . An ultrasound transducer comprising (i) an array transducer stack comprising a plurality of first kerf slots that extend a predetermined depth therein the stack, and wherein the plurality of first kerf slots define a plurality of ultrasonic array elements; (ii) a connector having an electrode for each array element; and (iii) a composite dielectric material comprising a matrix material and a particulate material on the bottom surface of the stack and a portion of the connector, wherein the matrix material is laser ablated at a lower fluence than the particulate material,
wherein the composite dielectric material is disposed over a portion of the bottom surface of the stack and the connector; wherein a trench in the composite dielectric material connects each array element to one of the electrodes of the connector; and wherein a metal deposited in each trench provides an electrical connection between each active element and one of the electrodes of the connector.

5 . The transducer of claim 4 , wherein the plurality of first kerf slots are filled with a solid material, and the bottom surface of the stack comprises depressions in the solid material.

6 . The transducer of claim 4 , further comprising a backing layer disposed over at least portion of the composite dielectric material, the trenches, and each array element.

7 . The transducer of claim 4 , further comprising a matching layer attached to the top surface of the stack.

8 . The transducer of claim 4 , further comprising a lens attached to the top surface of the stack.

9 . The transducer of claim 4 , wherein the array elements operate at a center frequency of at least 20 MHz.

10 . The transducer of claim 4 , wherein the composite dielectric layer is sloped adjacent to each of the array elements to provide apodization and to suppress side lobes in elevation.

11 . The transducer of claim 4 , further comprising a plurality of second kerf slots defined therein the piezoelectric stack, each second kerf slot extending a predetermined depth therein the stack, wherein each second kerf slot is positioned adjacent to at least one first kerf slot and the plurality of second kerf slots define a plurality of array sub-elements.

12 . A method of forming an ultrasonic matching layer, said method comprising the steps of:
(a) providing an acoustic array transducer stack comprising a piezoelectric layer and having a top surface and a plurality of array elements, wherein the top surface comprises a plurality of spacers not disposed over the plurality of array elements; (b) providing a lens assembly having a top surface and a bottom surface; (c) contacting the bottom surface of the lens assembly with the plurality of spacers; and (d) curing an adhesive between the top surface of the transducer stack and the bottom surface of the lens assembly to form the ultrasound matching layer, wherein the adhesive bonds to the bottom surface of the lens assembly and the top surface of the transducer stack, and the distance between the top surface of the transducer stack and the bottom surface of the lens assembly resulting from the plurality of spacers is appropriate for an ultrasound matching layer.

13 . The method of claim 12 , wherein the lens assembly comprises a lens and a second matching layer forming the bottom surface of the assembly.

14 . The method of claim 13 , wherein the lens comprises Rexolite or TPX.

15 . The method of claim 13 , wherein the second matching layer comprises cyanoacrylate.

16 . The method of claim 13 , wherein the second matching layer adheres directly to the lens.

17 . The method of claim 12 , wherein the transducer stack further comprises a plurality of first kerf slots that extend a predetermined depth therein the stack, and wherein the plurality of first kerf slots define the plurality array elements.

18 . The method of claim 12 , wherein the transducer stack further comprises third and fourth matching layers disposed between the piezoelectric layer and the matching layer of step (d).

19 . An ultrasound transducer comprising a lens assembly having a top and bottom surface, an array transducer stack having a top and bottom surface, and a matching layer adhering to the bottom surface of the lens assembly and the top surface of the transducer stack, wherein the transducer stack comprises a piezoelectric layer and a plurality of array elements, the top surface of the transducer stack comprises a plurality of spacers not disposed over the plurality of array elements, and the bottom of the lens assembly contacts the plurality of spacers.

20 . The transducer of claim 19 , wherein the transducer stack further comprises a plurality of first kerf slots that extend a predetermined depth therein the stack, and wherein the plurality of first kerf slots define the plurality array elements.

21 . The transducer of claim 20 , further comprising a plurality of second kerf slots defined therein the piezoelectric stack, each second kerf slot extending a predetermined depth therein the stack, wherein each second kerf slot is positioned adjacent to at least one first kerf slot and the plurality of second kerf slots define a plurality of array sub-elements.

22 . The transducer of claim 19 , wherein the lens assembly comprises a lens and a second matching layer forming the bottom surface of the assembly.

23 . The transducer of claim 22 , wherein the lens comprises Rexolite or TPX.

24 . The transducer of claim 23 , wherein the second matching layer comprises cyanoacrylate.

25 . The transducer of claim 22 , where

Assignees

• Fujifilm Sonosite Inc

Inventors

• Lukacs Marc
• Chaggares Nicholas Christopher
• Hirson Desmond
• Pang Guofeng

Classifications

• H01L41/08

  Electricity · mapped topic

• H01L41/083 Primary

  Electricity · mapped topic

• B06B1/0622 Primary

  on one surface · CPC title

• H04R31/00

  Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor {(manufacture of microstructural arrangements of deformable or non-deformable structures in general B81C1/00182)} · CPC title

• H10N30/50 Primary

  having a stacked or multilayer structure · CPC title