Sensor element and method for producing a sensor element

Patent metadata

Field	Value
Publication number	US-12320716-B2
Application number	US-202117639781-A
Country	US
Kind code	B2
Filing date	Aug 31, 2021
Priority date	Sep 2, 2020
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

In an embodiment a sensor element includes at least one carrier having a top side and a bottom side, the top side being electrically insulating, at least one functional layer including a material with a temperature-dependent electrical resistance, the functional layer being arranged on the carrier, at least two electrodes arranged on the carrier at a distance from one another and at least two contact pads configured for electrically contacting the sensor element, wherein a respective contact pad is arranged directly on a partial region of one of the electrodes, wherein the sensor element is configured to measure a temperature, and wherein the sensor element is configured for direct integration into an electrical system as a discrete component.

First claim

The invention claimed is:

1. A sensor element comprising:
at least one carrier having a top side and a bottom side, the top side being electrically insulating;
at least one functional layer comprising a material with a temperature-dependent electrical resistance, the functional layer being arranged on the carrier;
at least two electrodes arranged on the carrier at a distance from one another, wherein each electrode has a plurality of electrode fingers, and wherein the electrode fingers of the two electrodes are arranged alternately with respect to each other; and
at least two contact pads configured for electrically contacting the sensor element,
wherein a respective contact pad is arranged directly on a partial region of one of the at least two electrodes,
wherein the functional layer comprises an NTC ceramic based on an oxidic material in a perovskite structure type or a spinel structure type, or wherein the functional layer comprises an NTC ceramic based on a carbide or a nitride material, or wherein the functional layer comprises a thin layer of vanadium oxide or SiC,
wherein the sensor element is configured to measure a temperature, and
wherein the sensor element is configured for direct integration into an electrical system as a discrete component.

2. The sensor element according to claim 1 , wherein the functional layer only partially covers the top side of the carrier.

3. The sensor element according to claim 1 , further comprising an insulating layer located directly on the top side of the carrier.

4. The sensor element according to claim 1 , wherein the at least two electrodes are thin-film electrodes.

5. The sensor element according to claim 1 , wherein a respective electrode has an areal end region, and wherein the respective contact pad is arranged on the areal end region of the respective electrode.

6. The sensor element according to claim 1 , wherein the at least two electrodes are arranged directly on a top side of the functional layer.

7. The sensor element according to claim 1 , wherein the at least two electrodes are arranged directly on a bottom side of the functional layer.

8. The sensor element according to claim 1 , wherein the at least two contact pads protrude from a surface of the sensor element.

9. The sensor element according to claim 1 , further comprising a protective layer completely covering a top side of the sensor element except for the at least two contact pads.

10. The sensor element according to claim 1 , wherein the carrier comprises silicon, silicon carbide or glass.

11. The sensor element according to claim 1 , wherein a thickness of the sensor element is <100 μm.

12. The sensor element according to claim 1 , wherein the sensor element is designed for direct integration into a MEMS structure and/or into a SESUB structure.

13. The sensor element according to claim 1 , wherein a resistance of the sensor element is adjusted by a geometry of the functional layer and/or the at least two electrodes.

14. The sensor element according to claim 1 , wherein the carrier comprises AlN or Al 2 O 3 as a carrier material.

15. A method for producing a sensor element, the method comprising:
providing a carrier material for forming a carrier;
forming an electrically insulating layer on a top side of the carrier;
forming at least two electrodes on the carrier;
applying a functional material to a partial region of the at least two electrodes to form a functional layer;
sintering the functional layer;
applying a protective layer to a top side of the sensor element, the protective layer completely covering the top side except for two partial regions, the partial regions being arranged over areal end regions of the at least two electrodes to which contact pads are subsequently applicable;
forming the contact pads in the partial regions free of the protective layer for electrical contacting of the sensor element;
separating sensor elements by sawing with a diamond saw or by plasma etching so that components are not yet finally separated;
grinding the sensor elements from a bottom side, wherein a material is removed from a back side of the carrier to a defined final component thickness by grinding, wherein the carrier is a Si-wafer, and wherein the components are separated; and
optionally plasma etching of the bottom side of the Si-wafer to reduce micro-cracks.

16. The method according to claim 15 , wherein applying the functional material is carried out before forming the at least two electrodes, and wherein the at least two electrodes are formed directly on a top side of the functional layer.

17. A sensor element comprising:
at least one carrier having a top side and a bottom side, the top side being electrically insulating;
at least one functional layer comprising a material with a temperature-dependent electrical resistance, the functional layer being arranged on the carrier;
at least two electrodes arranged on the carrier at a distance from one another, wherein each electrode has a plurality of electrode fingers, and wherein the electrode fingers of the two electrodes are arranged alternately with respect to each other; and
at least two contact pads configured for electrically contacting the sensor element,
wherein a respective contact pad is arranged directly on a partial region of one of the at least two electrodes,
wherein the at least two electrodes are arranged directly on a bottom side of the functional layer,
wherein the sensor element is configured to measure a temperature,
wherein the sensor element is configured for direct integration into an electrical system as a discrete component, and
wherein the sensor element is designed for direct integration into a MEMS structure and/or into a SESUB structure.

Assignees

• Tdk Electronics Ag

Inventors

• Weidenfelder Anke
• Ihle Jan
• Ostrick Bernhard
• Krotosky Jeffrey

Classifications

• B81C1/00888

  Multistep processes involving only mechanical separation, e.g. grooving followed by cleaving · CPC title

• G01K2007/163

  provided with specially adapted connectors · CPC title

• G01K7/20 Primary

  in a specially-adapted circuit, e.g. bridge circuit · CPC title

• G01K7/16 Primary

  using resistive elements · CPC title