Sensor arrangement

• US 7,028,531 B2
• Filed: 02/01/2001
• Issued: 04/18/2006
• Est. Priority Date: 02/11/2000
• Status: Expired due to Fees

• Current Assignee: E+E Elektronik GES mbH
• Original Assignee: E+E Elektronik Ges.m.b.H. (Dr. Johannes Heidenhain GmbH)
• Inventors: Nikolaus, Gerhard
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): Hanley, John C
• Application Number:
  US10/203,600
• Publication Number:
  US 20030140681A1
• Time in Patent Office: 1,902 Days
• Field of Search: 73/290.1, 733/350.4, 73/290.5, 73/290.2, 324/664
• US Class Current: 73/29.05
• CPC Class Codes: B32B 17/10018 comprising only one glass sheet
• CPC Class Codes: B32B 17/1055 characterized by the resin layer, i.e. interlayer
• CPC Class Codes: B60H 1/00785 by the detection of humidity or frost
• CPC Class Codes: B60S 1/0822 characterized by the arrangement or type of detection means
• CPC Class Codes: B60S 1/0825 Capacitive rain sensor
• CPC Class Codes: B60S 1/0881 characterized by the attachment means on the windshield
• CPC Class Codes: B60S 1/0888 characterized by the attachment of the elements in a unit
• CPC Class Codes: G01K 1/16 Special arrangements for conducting heat from the object to the sensitive element

Abstract

A sensor arrangement is suitable for detecting if a windscreen of a motor vehicle is fogging. The sensor arrangement includes a heat conducting layer disposed on a supporting surface, the layer exhibiting good heat conducting properties. A support plate is arranged on top of the heat conducting layer, including a recess and several electrical conductor tracks. A moisture-sensitive sensor element is arranged in the region of the recess of the support plate. The sensor element is electroconductively connected to the conductor tracks on the support plate. The temperature difference between the sensor element and the supporting plate may not exceed a given limit when measurement occurs.

Claims

1. A sensor system for mounting on a supporting surface, comprising:

a thermally conductive layer having a high thermal conductivity arranged on the supporting surface;

a support plate on the thermally conductive layer including at least one recess, a plurality of electrical conductor tracks and a plurality of bores adjacent to the recess, the bores including a thermally conductive coating;

a humidity-sensitive sensor element positioned in a vicinity of the recess of the support plate and electroconductively connected to the conductor tracks on the support plate, the sensor element positioned on a side of the support plate above the recess;

a coating arranged in a specific surface area on at least one side of the support plate establishing a thermally conductive connection between the bores; and

a fastening arrangement configured to fasten the support plate on the supporting surface;

wherein the sensor system is configured so that a predefined temperature difference is not exceeded between the sensor element and the supporting surface during a measuring operation.

2. The sensor system according to claim 1, wherein the supporting surface includes an inside of a motor-vehicle pane facing a passenger compartment.

3. The sensor system according to claim 1, further comprising electronic components configured to process output signals from the sensor element mounted on the support plate.

4. The sensor system according to claim 3, wherein the electronic components include a protective coating.

5. The sensor system according to claim 1, wherein the support plate includes a detachable connection to a connecting cable.

6. The sensor system according to claim 1, wherein the support plate is made of FR4 material.

7. The sensor system according to claim 1, wherein the sensor element is configured as a capacitive thin-film humidity sensor having a humidity-sensitive dielectric arranged between a plurality of electrodes and a humidity-sensitive surface oriented toward the support plate.

8. The sensor system according to claim 1, wherein the sensor element is configured as an SMD component and on a side facing the support plate has electrically conductive contacts configured to connect to the conductor tracks of the support plate.

9. The sensor system according to claim 8, wherein the sensor element in at least one dimension is configured to be greater in length than the recess, and the electrically conductive contacts are arranged in contact areas outside of the recess.

10. The sensor system according to claim 1, wherein the thermally conductive coating is made of copper.

11. The sensor system according to claim 1, wherein the fastening arrangement includes a mechanical fastening arrangement.

12. A sensor system for mounting on a supporting surface, comprising:

a thermally conductive layer having a high thermal conductivity arranged on the supporting surface;

a support plate on the thermally conductive layer including at least one recess, a plurality of electrical conductor tracks and at least one bore adjacent to the recess, the bore including a thermally conductive coating;

a humidity-sensitive sensor element positioned in a vicinity of the recess of the support plate and electroconductively connected to the conductor tracks on the support plate, the sensor element positioned on a side of the support plate above the recess; and

a fastening arrangement configured to fasten the support plate on the supporting surface;

wherein the sensor system is configured so that a predefined temperature difference is not exceeded between the sensor element and the supporting surface during a measuring operation;

wherein the conductor tracks are arranged in the support plate;

wherein the sensor is arranged over the tracks and the recess, the tracks arranged in the support plate, the support plate arranged over the thermally conductive layer and the thermally conductive layer arranged over the supporting surface; and

wherein the supporting surface includes an inside of a motor-vehicle pane facing a passenger compartment.

13. The sensor system according to claim 12, further comprising electronic components configured to process output signals from the sensor element mounted on the support plate.

14. The sensor system according to claim 13, wherein the electronic components include a protective coating.

15. The sensor system according to claim 12, wherein the support plate includes a detachable connection to a connecting cable.

16. The sensor system according to claim 12, wherein the support plate is made of FR4 material.

17. The sensor system according to claim 12, wherein the sensor element is configured as a capacitive thin-film humidity sensor having a humidity-sensitive dielectric arranged between a plurality of electrodes and a humidity-sensitive surface oriented toward the support plate.

18. The sensor system according to claim 12, wherein the system is configured such that a temperature difference of 0.5°

C. between the sensor element and the supporting surface is not exceeded during the measuring operation.

19. The sensor system according to claim 12, wherein the sensor element is configured as an SMD component and on a side facing the support plate has electrically conductive contacts configured to connect to the conductor tracks of the support plate.

20. The sensor system according to claim 19, wherein the sensor element in at least one dimension is configured to be greater in length than the recess, and the electrically conductive contacts are arranged in contact areas outside of the recess.

21. The sensor system according to claim 12, wherein the thermally conductive coating is made of copper.

22. The sensor system according to claim 12, wherein the fastening arrangement includes a mechanical fastening arrangement.