Piezoelectric device mounted on integrated circuit chip

• US 20050189848A1
• Filed: 04/20/2005
• Published: 09/01/2005
• Est. Priority Date: 01/15/2003
• Status: Active Grant

• Current Assignee: Alfred E. Mann Foundation For Scientific Research
• Original Assignee: Alfred E. Mann Foundation For Scientific Research
• Inventors: Byers, Charles L., Schnittgrund, Gary D., Schulman, Joseph H.
• Granted Patent: US 7,271,525 B2
• Time in Patent Office: Days
• US Class Current: 310/348
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H03H 9/1021 the BAW device being of the cantilever type
• CPC Class Codes: H03H 9/54 comprising resonators of piezoelectric or electrostrictive material H03H9/64 takes precedence
• CPC Class Codes: H05K 13/04 Mounting of components , e.g. of leadless components
• CPC Class Codes: Y10T 29/49005 Acoustic transducer
• CPC Class Codes: Y10T 29/49007 Indicating transducer
• CPC Class Codes: Y10T 29/4908 Acoustic transducer

Abstract

An electronics filter circuit includes an electromechanical resonator that is mounted directly to the surface of a silicon integrated circuit, rather than being a surface mounted or leaded filter can on a circuit board. This filter circuit allows the integrated circuit electronic package to be significantly smaller than a conventional electromechanical resonator package. The electromechanical resonator may be protected during processing and during use with a protective cover that is made of a material such as titanium. The protective cover is attached to the integrated circuit chip.

Claims

1. An integrated circuit system configured for containment within an implantable electronic microdevice, said microdevice having an axial dimension of less than 60 mm and a lateral dimension of less than 6 mm and at least two electrodes for communicating electrical signals between said microdevice and living tissue;

said integrated circuit comprising;

an integrated circuit chip containing an electronic circuit;

an electromechanical resonator cantilever mounted to and supported by said integrated circuit chip and electrically coupled to said electronic circuit; and

said cantilever mounted resonator supported with an additional support that comprises a soft, flexible mounting material.

2. The integrated circuit system according to claim 1 wherein said additional support is comprised of silicon.

3. The integrated circuit system according to claim 1 wherein said at least one mounting pad is a gold bump.

4. The integrated circuit system according to claim 1 wherein said at least one mounting pad is electrically conductive.

5. The integrated circuit system according to claim 1 wherein said at least one mounting pad comprises an electrically conductive epoxy.

6. The integrated circuit system according to claim 1 wherein said at least one electromechanical resonator comprises quartz.

7. The integrated circuit system according to claim 1 wherein said electronic circuit is at least partially comprises an oscillator circuit.

8. The integrated circuit system according to claim 1 wherein said integrated circuit chip has a top surface and a bottom surface and at least one electromechanical resonator is mounted on said top surface.

9. The integrated circuit system according to claim 1 wherein said integrated circuit chip has a top surface and a bottom surface and at least one electromechanical resonator is mounted on said top surface of said integrated circuit chip and a second electromechanical resonator is mounted on said bottom surface of said integrated circuit chip.

10. The integrated circuit system according to claim 1 wherein said protective cover comprises titanium.

11. The integrated circuit system according to claim 1 wherein said microdevice is comprised of a biocompatible ceramic.

12. The integrated circuit system according to claim 1 wherein said electrodes are comprised of titanium or a titanium alloy.

13. A method of forming a circuit on an integrated circuit chip for containment within a microdevice having an axial dimension of less than 60 mm and a lateral dimension of less than 6 mm, comprising the steps of:

selecting an integrated circuit chip,

selecting at least one electromechanical resonator,

forming at least one mounting pad on said integrated circuit chip, and

attaching at least one electromechanical resonator to said mounting pad.

14. The method of forming a circuit according to claim 13 wherein said step of forming at least one mounting pad is forming said pad directly on said integrated circuit chip.

15. The method of forming a circuit according to claim 13 wherein said step of attaching said electromechanical resonator is adhesive bonding with an electrically conductive adhesive.

16. The method of forming a circuit according to claim 13 further comprising the step of attaching a protective cover over said electromechanical resonator.

17. The method of forming a circuit according to claim 13 further comprising the step of selecting a microdevice comprised of a biocompatible ceramic and at least two biocompatible electrodes.