IMPROVED HIGH-TEMPERATURE CHIP

Abstract

One aspect relates to a high-temperature sensor, having a coated substrate. The substrate contains a zirconium oxide or a zirconium oxide ceramic, at least one resistance structure and at least two connection contacts. The connection contacts electrically contact the resistance structure. The substrate is coated with an insulation layer. The insulation layer contains a metal oxide layer, the resistance structure and the free regions of the insulation layer, on which no resistance structure is arranged, are coated at least in regions with a ceramic intermediate layer, and a protective layer and/or a cover is arranged on the ceramic intermediate layer. At least one opening is formed in the insulation layer, which exposes at least sections of a surface of the substrate.

Claims

1-12. (canceled)

13. A high-temperature sensor comprising: a coated substrate, wherein the substrate contains a zirconium oxide or a zirconium oxide ceramic; at least one resistance structure; and at least two terminal contacts; wherein the terminal contacts make electrical contact with the resistance structure; wherein the substrate is coated with an insulation layer; wherein the insulation layer contains a metal oxide layer, the resistance structure and the exposed areas of the insulation layer, on which no resistance structure is arranged, are at least partially coated with a ceramic intermediate layer, and a protective layer or a cover is arranged on the ceramic intermediate layer; and wherein at least one opening is formed in the insulation layer, which opening exposes a surface of the substrate at least in sections.

14. The temperature sensor according to claim 13, wherein the at least one opening is designed in the shape of slots, wherein the width of the slots is between 5 μm and 1 mm.

15. The temperature sensor according to claim 13, wherein the at least one opening is designed in the shape of slots, wherein the width of the slots is between 20 μm and 100 μm.

16. The temperature sensor according to claim 14, wherein the slots of the at least one opening have longitudinal extensions formed parallel or perpendicular to a longitudinal extension of the substrate, or wherein the slots of the at least one opening have longitudinal extensions formed parallel to one another.

17. The temperature sensor according to claim 13, wherein the at least one opening exposes at least one side surface of the substrate.

18. The temperature sensor according to claim 13, wherein the at least one opening completely surrounds the resistance structure.

19. The temperature sensor according to claim 13, wherein the at least one opening partially frames at least one of the two terminal contacts of the resistance structure.

20. The temperature sensor according to claim 13, wherein the at least one opening is filled with a material of the protective layer.

21. The temperature sensor according to claim 13, wherein the zirconium oxide or the zirconium oxide in the zirconium oxide ceramic is stabilized with oxides of a trivalent and a pentavalent metal, or at least one electrode is arranged on at least one terminal contact next to the resistance structure on the insulation layer, wherein the electrode or electrodes are formed as one piece with the resistance structure.

22. The temperature sensor according to claim 13, wherein the insulation layer is an aluminum oxide layer.

23. The temperature sensor according to claim 13, wherein the ceramic intermediate layer has a thickness between 1 μm and 50 μm.

24. The temperature sensor according to claim 13, wherein the ceramic intermediate layer has a thickness between 4 μm and 10 μm.

25. The temperature sensor according to claim 13, wherein the protective layer includes a glass or a glass ceramic or the cover is a ceramic plate.

26. The temperature sensor according to claim 13, wherein the resistance structure includes a platinum material or a platinum alloy, or a platinum-based alloy.

Description

[0041] Further features and advantages of the invention emerge from the following description, in which preferred embodiments of the invention are explained with reference to schematic drawings.

[0042] The drawings show the following:

[0043] FIG. 1 an exploded schematic view of a temperature sensor known from the prior art;

[0044] FIG. 2a a schematic top view of an insulation layer having a resistance structure of a temperature sensor known from the prior art disposed thereon;

[0045] FIGS. 2b-2d schematic top views of the insulation layers having openings and resistance structures disposed thereon according to embodiments of the invention; and

[0046] FIGS. 3a and 3b schematic sectional views through a substrate having an insulation layer disposed thereon with openings, a resistance structure, an intermediate layer, and a protective layer according to an embodiment of the invention.

[0047] FIG. 1 shows an exploded schematic view of a temperature sensor known from the prior art. A meandering, layered resistance structure 11 is electrically connected to two terminal contacts 12, 13. The resistance structure 11 is framed on slightly more than two sides by two electrodes 14, 15.

[0048] A substrate 16 made of a stabilized zirconium oxide or a zirconium oxide ceramic is coated with an insulation layer 17 made of metal oxide, which ensures that the resistance structure 11 is not short-circuited by the zirconium oxide, which is conductive at high temperatures, and that any harmful interaction between the zirconium oxide and the resistance structure 11 is prevented.

[0049] On its side facing away from the substrate 16, the resistance structure 11 is provided with an intermediate layer 18 as a diffusion barrier, which in turn is provided with a protective layer 19 for passivation, which can consist of glass or a glass ceramic and is covered with a cover 20.

[0050] According to FIG. 1, a ceramic plate is applied to the protective layer 19 as a cover 20. The ceramic plate represents additional passivation and acts as a mechanical “protective shield” against abrasion by particles in the housing in which the actual temperature sensor is installed.

[0051] In the temperature sensor shown in FIG. 1, the terminal contacts 12, 13 of the temperature sensor are strain-relieved with connecting wires 21 and 22 via connection pads 23 and 24 with a fixation 25 consisting of an electrically insulating fixing drop. This fixation 25 consists of high-purity glass or glass ceramic.

[0052] In addition to the initially mentioned embodiment of the intermediate layer 18 as a diffusion barrier, it should be noted that this is applied either in the thin-film process with a thickness in the range from 0.2 to 10 μm, preferably 5 μm, or in the thick-film process with a thickness in the range from 5 to 50 μm, preferably 15 μm.

[0053] The thickness of the connection pads 23, 24 on the resistance structure 11 is in the range from 10 to 50 μm, preferably 20 μm. As a carrier, the substrate 16 has a thickness in the range from 0.1 mm to 1 mm, preferably 0.4 mm, particularly preferably 0.38 mm.

[0054] The terminal contacts 12, 13 are both arranged on one side. In addition, however, it is also possible to arrange both terminal contacts 12, 13 on opposite sides.

[0055] FIG. 2a shows a schematic top view of an insulation layer 17 having a resistance structure 11 of a temperature sensor known from the prior art disposed thereon. The insulation layer 17 and resistance structure 11 shown in FIG. 2a can be used, for example, in the temperature sensor shown in FIG. 1. The insulation layer 17 shown has no openings.

[0056] FIGS. 2b to 2d show schematic top views of the insulation layers 17 having openings 30, 30a-d and resistance structures 11 disposed thereon according to various embodiments of the invention.

[0057] In the embodiment shown in FIG. 2b, an opening 30, which exposes a surface of the substrate, is formed in the insulation layer 17. The opening 30 can be designed in such a way that a central segment is created in the insulation layer 17, which segment is preferably arranged in the middle of the substrate. The central segment has edges, in which the edges of the central segment do not have a common termination with the edges of the substrate. In the embodiment shown, the opening 30 is shown as a circumferential opening in the material of the insulation layer 17, which opening exposes a surface of the substrate. The edges of the substrate and the areas of the substrate surface adjoining the edges are not covered by the insulation layer. In this case, the insulation layer 17 can initially be applied completely to the surface of the substrate and then removed again in a circumferential edge region.

[0058] In the embodiment shown in FIG. 2c, the opening 30 in the insulation layer 17 is designed in the shape of a slot and completely surrounds the resistance structure 11 and the terminal contacts 12, 13. The slot width can be, for example, in a range from 10 μm to 1 mm.

[0059] FIG. 2d shows an embodiment in which several slot-shaped openings 30, 30a-d are made in the material of the insulation layer 17 and form several segments in the insulation layer 17. In the embodiment shown, individual slot-shaped openings 30, 30a-d surround the terminal contacts 12, 13 and the resistance structure 11.

[0060] FIGS. 3a and 3b are schematic sectional views through a substrate 16 having an insulation layer 17 disposed thereon having openings 30, a resistance structure 11, an intermediate layer 18, and a protective layer 19 according to an embodiment of the invention. In the embodiment shown, the material of the protective layer 19 completely fills the openings 17. The openings 17 filled with the material of the protective layer 19 form a diffusion barrier for foreign atoms from the edges of the insulation layer 17 into the central segment. There is no protective layer 19 in the area of the terminal contacts 12, 13, as is shown in FIG. 3b. In FIG. 3b, openings 30b and 30c are shown, which partially include the terminal contacts 12, 13 and opening 30d, which is arranged between the terminal contacts 12, 13.

[0061] The features of the invention disclosed in the preceding description and in the claims, figures, and exemplary embodiments can be essential both individually and in any combination for the implementation of the invention in its various embodiments.

LIST OF REFERENCE NUMERALS

[0062] 11 Resistance structure [0063] 12, 13 Terminal contact [0064] 14, 15 Electrode [0065] 16 Substrate [0066] 17 Insulation layer [0067] 18 Intermediate layer [0068] 19 Protective layer [0069] 20 Cover [0070] 21, 22 Connecting wire [0071] 23, 24 Connection pad [0072] 25 Fixation [0073] 30, 30a-d Opening