SENSOR DEVICE

• US 20100054299A1
• Filed: 11/02/2007
• Published: 03/04/2010
• Est. Priority Date: 11/13/2006
• Status: Active Grant

• Current Assignee: Vishay Bccomponents Beyschlag GMBH (Vishay Intertechnology Incorporated)
• Original Assignee: Vishay Bccomponents Beyschlag GMBH (Vishay Intertechnology Incorporated)
• Inventors: Werner, Wolfgang, Werth, Sascha, Aurich, Joachim
• Granted Patent: US 8,220,988 B2
• Time in Patent Office: Days
• US Class Current: 374/28
• CPC Class Codes: G01N 27/121 for determining moisture content, e.g. humidity, of the fluid moisture content of the tested material G01N27/048
• CPC Class Codes: Y10T 29/49124 On flat or curved insulated base, e.g., printed circuit, etc.
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

A sensor device is provided for detecting thawing on surfaces with interdigital electrodes formed in a resistance layer which is formed on a substrate. In order to develop the sensor device further so that the measuring speed of the sensor device is further increased, the disclosure proposes that the interdigital electrodes and recesses between the interdigital electrodes have a moisture-sensitive hydrophilic surface through condensation cores applied to it.

Claims

1. A sensor device (100) for detecting thawing on surfaces with interdigital electrodes (14) formed in a resistance layer (13), the layer is formed on a substrate (10), wherein interdigital electrodes (14) and recesses (16) have a moisture-sensitive hydrophilic surface (18) due to condensation cores (19) applied.

2. The sensor device according to claim 1, wherein the resistance layer (13) is formed from a metal oxide layer which is formed on the substrate (10).

3. The sensor device according to claim 1 wherein the condensation cores comprise parts of the metal oxide layer and parts of the substrate (10).

4. The sensor device according to claim 1, wherein the substrate (10) is one of aluminium oxide, circuit board material, glass or glass ceramic.

5. The sensor device according to claim 1, wherein two terminal contacts (11, 12) are applied to the substrate (10), the contacts are connected to interdigital electrodes (14).

6. The sensor device according to claim 1, wherein the condensation cores are sintered on.

7. The sensor device according to claim 2, wherein the metal oxide layer comprises ruthenium oxides, ruthenates or iridium oxides.

8. The sensor device according to claim 2, wherein the metal oxide layer is a metal oxide paste.

9. The sensor device according to claim 1, wherein non sintered-on condensation cores are removed.

10. The sensor device according to claim 1, wherein recesses (16) are provided between teeth (15) of the interdigital electrodes (14), the recesses are produced by laser beams (17), wherein the density of the condensation cores (19) on the interdigital electrodes (14) increases in the direction of the recesses (16).

11. A method for producing a sensor device (100) with a substrate (10), which is preferably formed from an aluminium oxide ceramic, wherein the formation of a moisture-sensitive hydrophilic surface (18) on the interdigital electrodes (14) and the recesses (16) simultaneously accompanies the production of interdigital electrodes (14), wherein condensation cores (19) are applied to the surface of the interdigital electrodes (14) and the recesses (16).

12. The method according to claim 11, comprising the following method steps:

a) application of contact electrodes (11, 12) to the substrate (10),

b) application of a resistance layer (13) to the substrate (10),

c) production of interdigital electrodes (14) in the resistance layer (13) by heating, melting and evaporating parts of the substrate and resistance layer by laser radiation,

d) condensation of parts of the evaporated substrate (10) and parts of the evaporated resistance layer (13) on the interdigital electrodes (14) and in the recesses (16) which are provided between the interdigital electrodes (14).

e) mechanical stabilisation of the condensation cores (19) on the interdigital electrodes (14) and/or in the recesses (16) by sintering.

13. The method according to claim 12, wherein a protective lacquer is first applied, followed by terminal electrodes that can be soldered, by galvanic separation, or that can be glued, and the protective lacquer is detached with the simultaneous removal of the condensation cores (19) not sintered on.

14. The method according to claim 11, wherein an aluminium oxide ceramic in a thick layer quality is used as the substrate (10).

15. The method according to claim 12, wherein the interdigital electrodes (14) are formed from a metal oxide layer, preferably of ruthenium oxide, ruthenates or iridium oxides.

16. The method according to claim 12, wherein the laser radiation (17) is carried out at a wavelength from 248 nm to 1200 nm.

17. The method according to claim 12, wherein the mechanical stabilisation takes place by a sintering process.

18. The method according to claim 12, wherein the condensation cores not sintered on are removed with a galvanic protection layer after galvanisation.

19. The method according to claim 12, wherein the method is not carried out in a vacuum.

20. The method according to claim 12, wherein a reaction zone (21), in which the heating, melting and evaporation of the substrate (10) and the resistance layer (13) takes place, is formed by the laser radiation (17).