Particle sensor and method for sensing particles in a fluid

Patent metadata

Field	Value
Publication number	US-10031062-B2
Application number	US-201615177404-A
Country	US
Kind code	B2
Filing date	Jun 9, 2016
Priority date	Jun 9, 2016
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

Various embodiments provide a particle sensor including: a first carrier, the first carrier including at least one heating structure and a light detecting structure, at least one spacer structure disposed over the first carrier, a second carrier disposed over the at least one spacer structure, the second carrier including a light emitting structure, wherein the first carrier, the second carrier and the at least one spacer structure are arranged to provide a channel for a fluid flow, wherein the light emitting structure is configured to emit light into the channel and wherein the light detecting structure is configured to detect light from the channel.

First claim

What is claimed is:

1. A particle sensor, comprising:
a first carrier, the first carrier comprising at least one heating structure, a light detecting device, and a first surface,
at least one spacer structure disposed over the first carrier,
a second carrier disposed over the at least one spacer structure, the second carrier comprising a light emitting device, and a first surface
wherein the first carrier, the second carrier and the at least one spacer structure are arranged to provide a channel for a fluid flow, wherein the first surface of the first carrier and the first surface of the second carrier face each other and are each exposed to the channel, wherein the light emitting device is configured to emit light into the channel and wherein the light detecting device is configured to detect light from the channel.

2. The particle sensor of claim 1 ,
wherein the channel has at least two openings defining a flow direction for a fluid from one of the at least two openings to another one of the at least two openings.

3. The particle sensor of claim 2 ,
wherein the channel is configured to have a length along the flow direction in the range from about 1 mm to about 10 mm.

4. The particle sensor of claim 2 ,
wherein the channel is configured to have a width perpendicular to the flow direction in the range from about 0.5 mm to about 2 mm.

5. The particle sensor of claim 4 ,
wherein the channel is configured to have a height perpendicular to the flow direction in the range from about 10 μm to about 500 μm.

6. The particle sensor of claim 2 , further comprising:
at least two temperature sensors, wherein one of the at least two temperature sensors is configured to measure a temperature of the fluid at one of the at least two openings and wherein another one of the at least two temperature sensors is configured to measure a temperature of the fluid at another one of the at least two openings.

7. The particle sensor of claim 1 , further comprising:
a driver circuit coupled to the at least one heating structure and configured to provide a heating current through the at least one heating structure.

8. The particle sensor of claim 7 ,
wherein the driver circuit is configured to control the heating current to provide a fluid flow with a flow velocity in the range from about 0.5 mm/s to about 5 mm/s.

9. The particle sensor of claim 1 , further comprising:
a temperature sensor configured to measure a temperature of a fluid that flows in the channel.

10. The particle sensor of claim 1 ,
wherein the first and second carriers each comprise a semiconductor substrate.

11. The particle sensor of claim 10 , wherein the light detecting device comprises a photodiode integrated in and/or over the first surface of the first carrier.

12. The particle sensor of claim 10 , wherein the light emitting device comprises a diode integrated in and/or over the first surface of the second carrier.

13. A particle sensor, comprising:
a first carrier;
an isolation structure disposed at least one of over and in the first carrier;
a cavity structure disposed at least one of over and in the first carrier, the cavity structure comprising at least one cavity that is free of solid material;
a heating layer disposed over the cavity structure, wherein the isolation structure isolates the heating layer from the first carrier;
an electrode structure electrically contacting the heating layer to provide an electrical heating current through the heating layer;
a light detecting device disposed at least one of over and in the first carrier,
at least one spacer structure disposed over the first carrier,
a second carrier disposed over the at least one spacer structure, the second carrier comprising a light emitting device,
wherein the first carrier, the second carrier and the at least one spacer structure are arranged to provide a channel for a fluid flow, wherein the heating layer is arranged to heat a fluid in the channel, wherein the light emitting device is configured to emit light into the channel, and wherein the light detecting device is configured to detect light from the channel.

14. The particle sensor of claim 13 , further comprising:
a driver circuit coupled to the electrode structure to provide a heating current through the heating layer.

15. The particle sensor of claim 13 ,
wherein the isolation structure comprises a trench structure filled with a thermally insulating material.

16. The particle sensor of claim 15 ;
wherein the trench structure completely laterally surrounds the heating layer and
wherein the thermally insulating material physically connects the heating layer to the first carrier.

17. The particle sensor of claim 13 ,
wherein the isolation structure comprises thermally insulating material disposed over the first carrier and wherein the thermally insulating material physically connects the heating layer to the first carrier.

18. The particle sensor of claim 13 ,
wherein the cavity structure is disposed between the first carrier and the heating layer.

19. The particle sensor of claim 13 ,
wherein the at least one cavity of the cavity structure is air-tightly sealed by the first carrier, the isolation structure, and the heating layer.

20. The particle sensor of claim 13 ,
wherein the at least one cavity of the cavity structure is air-tightly sealed and
wherein a vacuum is provided within the at least one cavity.

21. The particle sensor of claim 13 ,
wherein the light detecting device comprises at least one photo diode and wherein the light emitting device comprises at least one light emitting diode.

22. The particle sensor of claim 13 ,
wherein the first carrier comprises semiconductor material and wherein the heating layer comprises semiconductor material.

23. The particle sensor of claim 13 ,
wherein the isolation structure comprises an oxide.

Assignees

• Infineon Technologies Dresden Gmbh

Inventors

• Kautzsch Thoralf

Classifications

• G01N15/1425 Primary

  using an analyser being characterised by its control arrangement · CPC title

• G01N15/0205

  by optical means · CPC title

• G01N15/06 Primary

  Investigating concentration of particle suspensions (by weighing G01N5/00; investigating sedimentation of particle suspensions G01N15/04; investigating individual particles G01N15/10) · CPC title

• G01N15/1459

  the analysis being performed on a sample stream · CPC title

• G01N2015/1486

  Counting the particles · CPC title