Method for manufacturing transducer assembly with curved transducer array

• US 5,711,058 A
• Filed: 12/29/1995
• Issued: 01/27/1998
• Est. Priority Date: 11/21/1994
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Frey, Gregg W.
• Primary Examiner(s): Hall, Carl E.
• Application Number:
  US08/581,139
• Time in Patent Office: 760 Days
• Field of Search: 29/25.35, 310/327, 310/334, 310/335
• US Class Current: 29/25.35
• CPC Class Codes: B06B 1/0622 on one surface
• CPC Class Codes: G10K 11/004 Mounting transducers, e.g. provided with mechanical moving or orienting device mountings specially adapted to a particular sound-producing device, see the preceding groups G10K1/00 - G10K9/00, e.g. G10K1/26, G10K1/28, G10K9/22; arrangements of sonic watch equipment on submarines B63G8/39; buoys B63B22/00
• CPC Class Codes: G10K 11/02 Mechanical acoustic impedances; Impedance matching, e.g. by horns; Acoustic resonators
• CPC Class Codes: G10K 11/32 characterised by the shape of the source
• CPC Class Codes: Y10T 29/42 Piezoelectric device making

Abstract

A method of manufacturing a transducer assembly having a curved transducer array. The method includes the steps of fabricating a laminated assembly by bonding the following layers together: a layer of electrically conductive, acoustic matching material, a layer of piezoelectric ceramic, a flexible printed circuit board and a layer of acoustic damping material. The acoustic damping material changes from an inflexible state to a flexible state when heated. The laminated assembly is then diced to a depth so that the only undiced portion is a portion of the acoustic damping layer. A core body having a curved front face in the shape of a cylindrical section is fabricated. Then at least the undiced portion of the layer of acoustic damping material is heated into a flexible state. The heated undiced portion of the layer of acoustic damping material is flexed to conform to the curved front face of the core body. Then the flexed undiced portion of the layer of acoustic damping material is bonded to the curved front face of said core body. As a result, the piezoelectric elements are arranged along a curve.

Claims

1. A method of manufacturing a transducer assembly having a curved transducer array, comprising the steps of:

fabricating an array case having a planar bottom wall and a pair of side walls extending from the bottom wall to form a channel, said array case being made of electrically conductive, acoustic matching material and said side walls having a predetermined height;

fabricating a laminated assembly having a depth greater than said predetermined height of said side walls by bonding a stack of layers to said bottom wall of electrically conductive, acoustic matching material, said stack being arranged in said channel of said array case and comprising a layer of piezoelectric ceramic, a flexible printed circuit board and a layer of acoustic damping material arranged in that order, said piezoelectric ceramic layer being bonded to said bottom wall of electrically conductive, acoustic matching material, and said acoustic damping material having a property whereby said acoustic damping material changes from an inflexible state to a flexible state when heated;

dicing said flat laminated array to a depth so that said bottom wall and said side walls of electrically conductive, acoustic matching material, said layer of piezoelectric ceramic, and said flexible printed circuit board are completely cut in a depthwise direction into respective segments and said layer of acoustic damping material is only partially cut in said depthwise direction so that an undiced portion of said layer of acoustic damping material supports said respective segments;

fabricating a core body having a curved front face in the shape of a cylindrical section;

heating at least said undiced portion of said layer of acoustic damping material until said acoustic damping material is flexible;

flexing said heated undiced portion of said layer of acoustic damping material to conform to said curved front face of said core body; and

bonding said flexed undiced portion of said layer of acoustic damping material to said curved front face of said core body.

2. The method of manufacture as defined in claim 1, wherein said core body is made of acoustic damping material.

3. The method of manufacture as defined in claim 1, wherein said electrically conductive, acoustic matching material is metal-impregnated graphite.

4. The method of manufacture as defined in claim 1, wherein said laminated assembly further comprises a layer of electrically insulating, acoustic matching material which is bonded to said layer of electrically conductive, acoustic matching material.

5. The method of manufacture as defined in claim 1, wherein said acoustic damping material is epoxy resin impregnated with granules of metal oxide-loaded silicone rubber.

6. The method of manufacture as defined in claim 1, wherein said core body is made of material having a relatively high thermal conductivity.

7. The method of manufacture as defined in claim 6, wherein said material of relatively high thermal conductivity is aluminum alloy.

8. The method of manufacture as defined in claim 1, further comprising the step of slitting said flexible circuit board in two regions separated by an unslit region sandwiched between said layer of piezoelectric ceramic and said layer of acoustic damping material.

9. The method of manufacture as defined in claim 1, further comprising the step of electrically connecting a pair of electrically conductive ground plates to opposite sides of each segment of said layer of electrically conductive, acoustic matching material using electrically conductive epoxy.