PIEZOELECTRIC MICROSPEAKER AND METHOD OF FABRICATING THE SAME

• US 20100072860A1
• Filed: 04/23/2009
• Published: 03/25/2010
• Est. Priority Date: 09/22/2008
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Chung, Seok-whan, Jeong, Byung-gil, Kim, Dong-kyun
• Granted Patent: US 8,549,715 B2
• Time in Patent Office: Days
• US Class Current: 310/324
• CPC Class Codes: H04R 17/005 using a piezoelectric polymer
• CPC Class Codes: H04R 2201/003 Mems transducers or their use of the electrostatic type H04R19/005
• 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 30/074 by depositing piezoelectric or electrostrictive layers, e.g. aerosol or screen printing
• CPC Class Codes: H10N 30/082 by etching, e.g. lithography
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49401 Fluid pattern dispersing device making, e.g., ink jet

Abstract

Provided is a method of fabricating a piezoelectric microspeaker. According to the method, drive units having a piezoelectric layer and an electrode are symmetrically formed so as to be disposed over and under a diaphragm, respectively. When a thin conductive layer is used as the diaphragm, the diaphragm can be used as a common electrode. On the other hand, when a thin non-conductive layer is used as the diaphragm, a common electrode is necessary in each of the drive units.

Claims

1. A method of fabricating a piezoelectric microspeaker, the method comprising:

forming a lower drive unit by;

forming a first drive electrode by depositing a first thin conductive layer on a substrate and etching the first conductive layer,

forming a first piezoelectric plate by depositing a first piezoelectric layer on the first drive electrode and etching the first piezoelectric layer, and

forming a first common electrode by depositing a second conductive layer on the first piezoelectric plate and etching the second conductive layer;

forming a diaphragm by depositing a non-conductive layer on the first common electrode; and

forming an upper drive unit by;

forming a second common electrode by depositing a third conductive layer on the diaphragm and etching the third conductive layer,

forming a second piezoelectric plate by depositing a second piezoelectric layer on the second common electrode and etching the second piezoelectric layer, and

forming a second drive electrode by depositing a fourth conductive layer on the second piezoelectric plate and etching the fourth conductive layer.

2. The method of claim 1, wherein the non-conductive layer comprises a polymer.

3. The method of claim 1, wherein a central region of the diaphragm protrudes in accordance with a shape of the lower drive unit, and wherein an edge region of the diaphragm and the lower drive unit are substantially co-planar.

4. The method of claim 1, further comprising:

prior to the forming the lower drive unit, etching a part of the substrate to form a cavity;

wherein the lower drive unit is formed substantially within the cavity.

5. The method of claim 4, wherein the diaphragm is substantially planar.

6. A method of fabricating a piezoelectric microspeaker, the method comprising:

forming a lower drive unit by depositing a first conductive layer on a substrate, etching the first conductive layer, and depositing a first piezoelectric layer on the first conductive layer, and etching the first piezoelectric layer;

forming a diaphragm by depositing a second conductive layer on the lower drive unit and etching the second conductive layer; and

forming an upper drive unit by depositing a second piezoelectric layer on the diaphragm, etching the second piezoelectric layer, depositing a third conductive layer on the second piezoelectric layer, and etching the third conductive layer.

7. The method of claim 6, wherein a central region of the diaphragm protrudes in accordance with a shape of the lower drive unit, and wherein an edge region of the diaphragm and the lower drive unit are substantially co-planar.

8. The method of claim 6, further comprising:

prior to the forming the lower drive unit, etching a part of the substrate to form a cavity;

wherein the lower drive unit is formed substantially within the cavity.

9. The method of claim 8, wherein the diaphragm is substantially planar.

10. A piezoelectric microspeaker fabricated according to a method comprising:

forming a lower drive unit by;

forming a first drive electrode by depositing a first thin conductive layer on a substrate and etching the first conductive layer,

forming a first piezoelectric plate by depositing a first piezoelectric layer on the first drive electrode and etching the first piezoelectric layer, and

forming a first common electrode by depositing a second conductive layer on the first piezoelectric plate and etching the second conductive layer;

forming a diaphragm by depositing a non-conductive layer on the first common electrode; and

forming an upper drive unit by;

forming a second common electrode by depositing a third conductive layer on the diaphragm and etching the third conductive layer,

forming a second piezoelectric plate by depositing a second piezoelectric layer on the second common electrode and etching the second piezoelectric layer, and

forming a second drive electrode by depositing a fourth conductive layer on the second piezoelectric plate and etching the fourth conductive layer.

11. A piezoelectric microspeaker fabricated according to a method comprising:

forming a lower drive unit by depositing a first conductive layer on a substrate, etching the first conductive layer, depositing a first piezoelectric layer on the first conductive layer, and etching the first piezoelectric layer;

forming a diaphragm by depositing a second conductive layer on the lower drive unit and etching the second conductive layer; and

forming an upper drive unit by depositing a second piezoelectric layer on the diaphragm, etching the second piezoelectric layer, depositing a third conductive layer on the second piezoelectric layer, and etching the third conductive layer.