Method Of Making A Piezoelectric Device

• US 20090047445A1
• Filed: 08/13/2008
• Published: 02/19/2009
• Est. Priority Date: 08/13/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Ultra-Scan Corporation (Qualcomm, Inc.)
• Inventors: Kitchens, Jack C., Schneider, John K.
• Granted Patent: US 7,955,641 B2
• Time in Patent Office: Days
• US Class Current: 427/562
• CPC Class Codes: H10N 30/06 Forming electrodes or interconnections, e.g. leads or terminals
• CPC Class Codes: H10N 30/098 Forming organic materials
• CPC Class Codes: Y10T 29/42 Piezoelectric device making

Abstract

A method of forming a piezoelectric device is disclosed. In one such method, a coating material is formed. The coating material has a piezoelectric precursor. The coating material is applied to a first electrode. The precursor is heated to a temperature that is above the Curie temperature of the precursor, but below the melting temperature of the precursor. While the precursor is above its Curie temperature, a voltage is applied across the precursor. While the voltage is applied across the precursor, the temperature of the precursor is reduced to below the Curie temperature.

Claims

1. A method of making a piezoelectric device, comprising:

forming a coating material having piezoelectric precursor;

applying the coating material to a first electrode;

applying a second electrode to the precursor;

heating the precursor to a temperature that is above the Curie temperature of the precursor, but below the melting temperature of the precursor;

applying a voltage across the precursor; and

reducing the temperature to below the Curie temperature while the voltage is applied.

2. The method of claim 1, wherein the coating material includes a liquid carrier.

3. The method of claim 2, wherein the carrier is a ketone solvent.

4. The method of claim 2, wherein the carrier includes water.

5. The method of claim 1, wherein the coating material is a solution.

6. The method of claim 1, wherein the coating material is a dispersion.

7. The method of claim 1, wherein the piezoelectric precursor is a polymer material.

8. The method of claim 7, wherein the polymer material is PVDF.

9. The method of claim 1, wherein the piezoelectric precursor is a co-polymer material.

10. The method of claim 9, wherein the co-polymer material is PVDF-TrFE.

11. The method of claim 1, wherein the precursor is a ceramic material.

12. The method of claim 11, wherein the ceramic material is lead zirconium titanate.

13. The method of claim 1, wherein the coating material is formed to a desired viscosity.

14. The method of claim 1, wherein the coating material includes color bodies.

15. The method of claim 1, wherein the coating material includes an adhesion promoting agent.

16. The method of claim 1, wherein applying the second electrode occurs prior to heating the precursor material to above the Curie temperature.

17. The method of claim 1, wherein applying the second electrode occurs after heating the precursor material to above the Curie temperature.

18. The method of claim 1, wherein the voltage is applied via the first and second electrodes.

19. The method of claim 1, wherein the voltage is applied by establishing a corona field.

20. The method of claim 1, wherein applying the coating material is accomplished by spraying the coating material.

21. The method of claim 1, wherein applying the coating material is accomplished by using a pen.

22. The method of claim 1, wherein applying the coating material is accomplished by using a screen.