POLYMER BULK ACOUSTIC RESONATOR

• US 20070063793A1
• Filed: 05/04/2006
• Published: 03/22/2007
• Est. Priority Date: 09/22/2005
• Status: Active Grant

• Current Assignee: Penn State Research Foundation (Pennsylvania State University)
• Original Assignee: Penn State Research Foundation (Pennsylvania State University)
• Inventors: Zhang, Qiming, Jang, Sei-Joo
• Granted Patent: US 7,362,035 B2
• Time in Patent Office: Days
• US Class Current: 333/187
• CPC Class Codes: H03H 3/04 for obtaining desired frequency or temperature coefficient
• CPC Class Codes: H03H 9/02015 Characteristics of piezoelectric layers, e.g. cutting angles
• CPC Class Codes: H03H 9/172 Means for mounting on a substrate, i.e. means constituting the material interface confining the waves to a volume
• CPC Class Codes: H03H 9/175 Acoustic mirrors
• 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: Y10S 310/80 Piezoelectric polymers, e.g. PVDF
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49005 Acoustic transducer
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

A polymer bulk acoustic resonator that includes an active semiconductor layer, a first thin film electrode layer applied to the semiconductor layer, a thin film electro-active polymer layer applied to the first thin film electrode layer; and a second thin film electrode layer applied to the thin film electro-active polymer layer.

Claims

1. A polymer bulk acoustic resonator comprising:

an active semiconductor layer;

a first thin film electrode layer applied to said semiconductor layer;

a thin film electro-active polymer layer applied to said first thin film electrode layer; and

a second thin film electrode layer applied to said thin film electro-active polymer layer.

2. The polymer bulk acoustic resonator of claim 1, wherein in said thin film electro-active polymer layer is a polymer electret film.

3. The polymer bulk acoustic resonator of claim 1, further including a Bragg Reflector applied between said first thin film electrode layer and said thin film electro-active polymer layer.

4. The polymer bulk acoustic resonator of claim 1, further including a reduced Bragg Reflector applied between said first thin film electrode layer and said thin film electro-active polymer layer.

5. The polymer bulk acoustic resonator of claim 1, wherein in said thin film electro-active polymer layer is a polyurea piezoelectric film.

6. The polymer bulk acoustic resonator of claim 4, wherein in said thin film electro-active polymer layer is a polyurea piezoelectric film.

7. The polymer bulk acoustic resonator of claim 1, wherein in said thin film electro-active polymer layer is a piezoelectric oligomer film.

8. The polymer bulk acoustic resonator of claim 4, wherein in said thin film electro-active polymer layer is a piezoelectric oligomer film.

9. The polymer bulk acoustic resonator of claim 4, wherein said first thin film electrode layer applied to said semiconductor layer is a heavy metal film of high acoustic impendence and also is the first layer of said reduced Bragg Reflector.

10. The polymer bulk acoustic resonator of claim 1, wherein said first thin film electrode layer applied to said semiconductor layer is a heavy metal film of high acoustic impendence to improve acoustic isolation of said thin film electro-active polymer layer applied to said first thin film electrode layer.

11. The polymer bulk acoustic resonator of claim 4, wherein said semiconductor layer includes at least one switch and said electro-active polymer layer is a frequency signal filter.

12. The polymer bulk acoustic resonator of claim 4, wherein said semiconductor layer includes at least one amplifier and said electro-active polymer layer is a frequency signal filter.

13. The polymer bulk acoustic resonator of claim 4, wherein said semiconductor layer includes at least one signal processor and said electro-active polymer layer is a frequency signal filter.

14. A method of making a polymer bulk acoustic resonator comprising;

applying a first thin film electrode layer to a semiconductor layer;

applying a thin film electro-active polymer layer to the first thin film electrode layer, by evaporating a stoichiometrically balanced monomer sample on said first thin film electrode layer;

annealing said evaporated sample which has been applied to said first thin film electrode layer; and

applying a second thin film electrode layer applied to the thin film electro-active polymer layer.

15. The method of claim 14, further including poling said thin film electro-active polymer layer after annealing to impart piezoelectric activity;

16. The method of claim 14, further including applying alternating layers of metal film and polymers to said first thin film electrode layer before applying said thin film electro-active polymer layer to form a reduced Bragg Reflector between said first thin film electrode layer and said thin film electro-active polymer layer.

17. A method of making a polymer bulk acoustic resonator comprising;

applying a first thin film electrode layer to a semiconductor layer;

applying a thin film electro-active oligomer layer to the first thin film electrode layer; and

applying a second thin film electrode layer applied to the thin film electro-active polymer layer.

18. The method of claim 17, further including applying alternating layers of metal film and polymers to said first thin film electrode layer before applying said thin film electro-active polymer layer to form a reduced Bragg Reflector.

19. The method of claim 17, wherein said thin film electro-active oligomer layer is applied to said first thin film electrode layer by a method of thermal evaporation, whereby oligomers are placed in a crucible and heated to above room temperature and said first thin film electrode layer is held at a temperature near room temperature or below.

20. The method of claim 17, wherein said thin film electro-active oligomer layer is applied to said first thin film electrode layer by using a spin cast techniques.

21. The method of claim 17, further including poling said thin film electro-active oligmor layer to impart piezoelectric activity.

22. A method of making a polymer bulk acoustic resonator comprising;

applying a first thin film electrode layer to a semiconductor layer;

applying a polymer electret thin film layer to the first thin film electrode layer; and

applying a second thin film electrode layer applied to the thin film electro-active polymer layer.

23. The method of claim 22, wherein said polymer electret thin film layer is applied as a bilayer film with each layer having a different elastic modulus.

24. The method of claim 22, wherein said polymer electret thin film layer is applied as a bilayer film with each layer having a different thickness.

25. The method of claim 22, further including poling said polymer electret thin film layer to impart piezoelectric activity;

26. The method of making a polymer bulk acoustic resonator comprising;

applying a first thin film electrode layer to a semiconductor layer;

applying a thin film electro-active polymer layer to the first thin film electrode layer; and

applying a second thin film electrode layer applied to the thin film electro-active polymer layer.

27. The method of claim 26, further including applying alternating layers of metal film and polymers to said first thin film electrode layer before applying said thin film electro-active polymer layer to form a reduced Bragg Reflector between said first thin film electrode layer and said thin film electro-active polymer layer.