Integrated IR Source and Acoustic Detector for Photoacoustic Gas Sensor

• US 20110296900A1
• Filed: 06/03/2010
• Published: 12/08/2011
• Est. Priority Date: 06/03/2010
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Thorson, Walter
• Granted Patent: US 8,695,402 B2
• Time in Patent Office: Days
• US Class Current: 73/24.02
• CPC Class Codes: G01N 21/1702 with opto-acoustic detection, e.g. for gases or analysing solids

Abstract

A photoacoustic gas detector includes an integrated source, infrared filter and an acoustic sensor. The source, filter and acoustic sensor can be integrated onto one or more semiconductor substrates, such as silicon. Processing circuitry can also be integrated onto the substrate. Further, the source, filter and acoustic sensor can be integrated into a single component package, such as a metal can transistor package.

Claims

1. A photoacoustic gas sensor component comprising:

an infrared source carried on a semiconductor substrate;

an integrated microphone formed on one of, the same or a second semiconductor substrate, and an infrared wavelength selective bandpass filter carried on a third substrate.

2. The photoacoustic gas sensor component as in claim 1 which includes an integrated component package for housing together the source, the microphone and an infrared filter.

3. The photoacoustic gas sensor component of claim 2 which additionally includes signal acquisition and signal processing circuitry formed on a semiconductor substrate within the integrated component package.

4. The photoacoustic gas sensor component as in claim 1 where the microphone is implemented as a MEMS-type transducer.

5. The phototacoustic gas sensor component of claim 2 where the packaging of the component housing conforms to the requirements of a metal can transistor outline package or other industry standard semiconductor device packaging format.

6. The phototacoustic gas sensor component of claim 3 where the packaging of the component housing conforms to the requirements of a metal can transistor outline package or other industry standard semiconductor device packaging format.

7. The photoacoustic gas sensor component of claim 2 where the infrared source is substantially planar.

8. The photoacoustic gas sensor component of claim 3 where the infrared source is substantially planar.

9. The photoacoustic gas sensor component of claim 2 where the infrared source includes a thin-film conductor.

10. The photoacoustic gas sensor component of claim 3 where the infrared source includes a thin-film conductor.

11. The photoacoustic gas sensor component of claim 2 where the infrared source includes a filament conductor.

12. The photoacoustic gas sensor component of claim 3 where the infrared source includes a filament conductor.

13. The photoacoustic gas sensor component of claim 2 where the infrared source includes an infrared light emitting diode.

14. The photoacoustic gas sensor component of claim 3 where. the infrared source includes and infrared light emitting diode.

15. The photoacoustic gas sensor component of claim 2 where the wavelength selective bandpass filter is a selected from a class which includes at least a dialectric or a dichroic type IR filter.

16. The photoacoustic gas sensor component of claim 3 where the wavelength selective bandpass filter is a selected from a class which includes at least a dialectric or a dichroic type IR filter.

17. The photoacoustic gas sensor component of claim 2 where the wavelength selective bandpass filter is a tunable Fabry-Perot filter.

18. The photoacoustic gas sensor component of claim 3 where the wavelength selective bandpass filter is a tunable Fabry-Perot filter.

19. A photoacoustic gas sensor apparatus comprising:

an integrated photoacoustic gas sensor component having an infrared source carried on a semiconductor substrate, an integrated microphone formed on one of, the same or a second semiconductor substrate, an infrared wavelength selective bandpass filter carried on a third substrate, and a measurement cell.

20. An apparatus comprising:

a first housing which defines an internal sensing volume; and

a second housing which carries an integrated gas sensing component which includes at least an infrared source carried on a semiconductor substrate, and a microphone formed on the same or a different semiconductor substrate where the second housing is carried at an open end of the first housing.

21. An apparatus as in claim 20 where the second housing also carries signal acquisition and signal processing circuitry formed on a semiconductor substrate.