Methods for manufacturing ultrasound transducers and other components

• US 10,596,597 B2
• Filed: 01/27/2017
• Issued: 03/24/2020
• Est. Priority Date: 09/18/2008
• Status: Active Grant

• Current Assignee: FUJIFILM SonoSite, Inc. (Fujifilm Holdings Corporation)
• Original Assignee: FUJIFILM SonoSite, Inc. (Fujifilm Holdings Corporation)
• Inventors: Chaggares, N. Christopher, Rieder, Eric
• Primary Examiner(s): Dougherty, Thomas M
• Application Number:
  US15/418,483
• Publication Number:
  US 20170197232A1
• Time in Patent Office: 1,152 Days
• Field of Search: 310322, 310334, 310365, 310366, 29 2535
• CPC Class Codes: B06B 1/0207 Driving circuits specially adapted for particular applications, see the relevant subclass, e.g. G01; circuits for steering transducer arrays G10K11/34; basic circuits H03
• CPC Class Codes: B06B 1/0622 on one surface
• CPC Class Codes: B06B 1/0629 Square array
• CPC Class Codes: H05K 1/028 Bending or folding regions of flexible printed circuits H05K1/0283 takes precedence
• CPC Class Codes: H05K 1/0298 Multilayer circuits
• CPC Class Codes: H05K 1/181 associated with surface mounted components
• CPC Class Codes: H05K 1/189 characterised by the use of a flexible or folded printed circuit H05K3/326 takes precedence
• CPC Class Codes: H05K 2203/0361 Stripping a part of an upper metal layer to expose a lower metal layer, e.g. by etching or using a laser
• CPC Class Codes: H05K 3/02 in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding
• CPC Class Codes: H05K 3/064 Photoresists
• CPC Class Codes: H05K 3/305 Affixing by adhesive
• CPC Class Codes: H05K 3/32 electrically connecting electric components or wires to printed circuits
• CPC Class Codes: H10N 30/063 Forming interconnections, e.g. connection electrodes of multilayered piezoelectric or electrostrictive parts
• CPC Class Codes: H10N 30/875 Further connection or lead arrangements, e.g. flexible wiring boards, terminal pins

Abstract

The disclosed technology features methods for the manufacture of electrical components such as ultrasound transducers. In particular, the disclosed technology provides methods of creating an ultrasonic transducer by connecting one or more multi-layer printed circuits to an array of ultrasound transducer elements. In one embodiment, the printed circuits have traces in a single layer that are spaced by a distance that is greater than a pitch of the transducer elements to which the multi-layer printed circuit is to be connected. However the traces from all the layers in the multi-layer printed circuit are interleaved to have a pitch that is equal to the pitch of the transducer elements. The disclosed technology also features ultrasound transducers produced by the methods described herein.

Claims

1. An ultrasonic transducer assembly comprising:

a transducer array comprising a number of spaced transducer elements;

at least one printed circuit including a plurality of trace layers, each layer having a plurality of conductive traces therein that are electrically coupled to a corresponding transducer element, wherein the conductive traces in any single trace layer at a point where the traces are coupled to the transducer elements are spaced farther apart than a distance between adjacent transducer elements in the transducer array; and

a plurality of interconnections, each interconnection electrically coupling a conductive trace of the printed circuit to a corresponding transducer element.

2. The ultrasonic transducer assembly of claim 1, wherein the interconnections have a width that is narrower than a width of the transducer elements to which they are connected.

3. The ultrasonic transducer assembly of claim 1, wherein the transducer array has a length and a width that is shorter than the length, and wherein the printed circuit has traces therein that extend along the printed circuit in a direction that is generally parallel to the length of the transducer array.

4. The ultrasonic transducer assembly of claim 1, wherein the transducer array has a length and a width that is shorter than the length, and wherein the printed circuit has traces therein that generally extend in a direction of the width of the transducer array.

5. The ultrasonic transducer assembly of claim 1, wherein the transducer assembly includes a single printed circuit connected to one side of the transducer elements.

6. The ultrasonic transducer assembly of claim 1, wherein the transducer assembly includes two printed circuits connected to opposite sides of the transducer elements.

7. The ultrasonic transducer assembly of claim 1, wherein the printed circuit includes at least one ground plane that separates at least two layers of the plurality of trace layers.

8. The ultrasonic transducer assembly of claim 1, wherein neighboring transducer elements of the transducer array are electrically connected to conductive traces disposed in different trace layers of the printed circuit.

9. The ultrasonic transducer assembly of claim 1, wherein the printed circuit is a printed flex circuit.

10. An ultrasonic transducer assembly comprising:

an ultrasonic transducer array comprising a set of even transducer elements and a set of odd transducer elements alternating with the even transducer elements, the even transducer elements and the odd transducer elements having a pitch therebetween;

at least two multi-layer printed circuits, each multi-layer printed circuit comprising a plurality of trace layers having a conductive traces therein, wherein the conductive traces on each of the multi-layer printed circuits are interleaved such the traces have a pitch equal to the pitch of the even or odd transducer elements but the traces in any single trace layer of multi-layer printed circuits have a pitch that is greater than the pitch of the even or odd transducer elements; and

a plurality of interconnections, each interconnection coupling a conductive trace of the multi-layer printed circuit to a transducer element.

11. The ultrasonic transducer assembly of claim 10, wherein the transducer array has a length and a width that is shorter than the length and wherein the traces in the multi-layer printed circuits generally extend in a direction of the width of the transducer array.

12. The ultrasonic transducer assembly of claim 10, wherein the transducer array has a length and a width that is shorter than the length and wherein the traces in the multi-layer printed circuits extend in a direction that is generally aligned with the length of the transducer array.

13. The ultrasonic transducer assembly of claim 10, wherein the multi-layer printed circuits include at least one ground layer that separates at least two trace layers in the printed circuit.

14. The ultrasonic transducer assembly of claim 10, wherein neighboring transducer elements of the transducer array are electrically connected to conductive traces disposed on different multi-layer printed circuits.

15. The ultrasonic transducer assembly of claim 10, wherein the at least two multi-layer printed circuits are multi-layer printed flex circuits.

16. A multi-layer printed circuit for use in connecting to transducer elements of an ultrasonic transducer having a number of adjacent transducer elements that are separated by a pitch distance, comprising:

at least two trace layers having a plurality of conductive traces therein whereby the conductive traces in each trace layer are separated by a distance that is greater than the pitch between adjacent transducer elements at a point where they are to be connected to the transducer elements but the conductive traces from each of the at least two trace layers are interleaved such that the traces match the pitch of the transducer elements.

17. The multi-layer printed circuit of claim 16, further comprising at least one additional layer, the at least one additional layer including an additional plurality of conductive traces.

18. A method of assembling an ultrasonic transducer assembly, by:

securing a multi-layer printed circuit to an ultrasound transducer array with an adhesive, wherein the multi-layer printed circuit is of the type that has at least two trace layers having a plurality of conductive traces therein that are separated by a distance that is greater than a pitch between adjacent transducer elements in the transducer array but the conductive traces from each of the at least two layers are interleaved such that the traces from all of the at least two trace layers match the pitch of the transducer elements in the transducer array;

creating channels in the adhesive between the transducer elements and the traces in the multi-layer printed circuit;

depositing a conductor material over the ultrasound array and at least a portion of the multi-layer printed circuit that has been channeled;

placing a resist material over the conductor material;

removing a portion of the resist material where the conductor material is not desired;

etching the conductor material to remove most of the conductor material where it is not desired; and

removing any additional conductor material where it is not desired with a laser.