Transducer with piezoelectric, conductive and dielectric membrane

• US 10,003,888 B2
• Filed: 07/21/2014
• Issued: 06/19/2018
• Est. Priority Date: 11/29/2011
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Inventors: Stephanou, Philip Jason, Burns, David William, Shenoy, Ravindra V.
• Primary Examiner(s): Ni, Suhan
• Application Number:
  US14/336,744
• Publication Number:
  US 20140328504A1
• Time in Patent Office: 1,429 Days
• Field of Search: 381151, 381190-191, 381431
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/1637 Details related to the display arrangement, including those related to the mounting of the display in the housing
• CPC Class Codes: H04R 17/00 Piezoelectric transducers; Electrostrictive transducers piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners H10N30/00
• CPC Class Codes: H04R 2201/003 Mems transducers or their use
• CPC Class Codes: H04R 2201/401 2D or 3D arrays of transducers
• CPC Class Codes: H04R 2499/15 Transducers incorporated in visual displaying devices, e.g. televisions, computer displays, laptops
• CPC Class Codes: H04R 31/00 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 Class Codes: H10N 30/07 Forming of piezoelectric or electrostrictive parts or bodies on an electrical element or another base
• CPC Class Codes: H10N 30/40 with electrical input and electrical output, e.g. functioning as transformers
• CPC Class Codes: H10N 30/80 Constructional details
• CPC Class Codes: Y10T 29/42 Piezoelectric device making

Abstract

This disclosure provides systems, methods and apparatus for microspeaker devices. In one aspect, a microspeaker element may include a deformable dielectric membrane that spans a speaker cavity. The deformable dielectric membrane can include a piezoactuator and a dielectric layer. Upon application of a driving signal to the piezoactuator, the dielectric layer can deflect, producing sound. In some implementations, an array of microspeaker elements can be encapsulated between a glass substrate and a cover glass. Sound generated by the microspeaker elements can be emitted through a speaker grill formed in the cover glass.

Claims

1. An apparatus, comprising:

a substrate;

a deformable membrane; and

a cavity disposed between the substrate and the deformable membrane such that the deformable membrane spans the cavity,

the deformable membrane including a first piezoelectric layer between first and second metal layers, and a dielectric layer, wherein the dielectric layer is capable of deforming on application of a drive voltage across the first piezoelectric layer to thereby generate an ultrasonic wave, wherein the cavity is a sealed cavity that is enclosed on all sides, and wherein the dielectric layer is directly engaged with the substrate.

2. The apparatus of claim 1, wherein the dielectric layer includes at least one of an oxide, nitride or oxynitride material.

3. The apparatus of claim 1, wherein the first piezoelectric layer includes at least one of polyvinylidene fluoride (PVDF), aluminum nitride (AlN), lead zirconate titanate (Pb[Zr_xTi_1-x]O₃, 0≤

x≤

1), gallium arsenide (GaAs) or zinc oxide (ZnO).

4. The apparatus of claim 1, wherein the first piezoelectric layer is disposed between the dielectric layer and the substrate.

5. The apparatus of claim 1, wherein the dielectric layer is disposed between the first piezoelectric layer and the substrate.

6. The apparatus of claim 1, wherein the first piezoelectric layer spans the cavity.

7. The apparatus of claim 1, wherein the first piezoelectric layer is centered over the cavity.

8. The apparatus of claim 1, wherein the first piezoelectric layer overlies a peripheral region of the cavity.

9. The apparatus of claim 1, wherein the deformable membrane further includes a second piezoelectric layer sandwiched between third and fourth metal layers.

10. The apparatus of claim 9, wherein the first and second piezoelectric layers are located on opposite sides of the dielectric layer.

11. The apparatus of claim 1, wherein the substrate is a glass substrate.

12. The apparatus of claim 1, wherein the cavity is defined by a portion of the substrate and the deformable membrane and wherein the portion of the substrate that defines the cavity is planar.

13. An apparatus, comprising:

a substrate;

a deformable membrane; and

a cavity disposed between the substrate and the deformable membrane such that the deformable membrane spans the cavity,

the deformable membrane including a first piezoelectric layer between first and second metal layers, and a dielectric layer, wherein the dielectric layer is capable of deforming on application of a drive voltage across the first piezoelectric layer to thereby generate an ultrasonic wave, wherein the cavity is a sealed cavity that is enclosed on all sides, and wherein the dielectric layer extends over the entire area of the cavity.

14. The apparatus of claim 13, wherein the dielectric layer includes at least one of an oxide, nitride or oxynitride material.

15. The apparatus of claim 13, wherein the first piezoelectric layer includes at least one of polyvinylidene fluoride (PVDF), aluminum nitride (AlN), lead zirconate titanate (Pb[Zr_xTi_1-x]O₃, 0≤

x≤

1), gallium arsenide (GaAs) or zinc oxide (ZnO).

16. The apparatus of claim 13, wherein the first piezoelectric layer is disposed between the dielectric layer and the substrate.

17. The apparatus of claim 13, wherein the dielectric layer is disposed between the first piezoelectric layer and the substrate.

18. The apparatus of claim 13, wherein the first piezoelectric layer spans the cavity.

19. The apparatus of claim 13, wherein the first piezoelectric layer is centered over the cavity.

20. The apparatus of claim 13, wherein the first piezoelectric layer overlies a peripheral region of the cavity.