Sensor for detecting electrically conductive and/or polarizable particles, sensor system, method for operating a sensor, method for producing a sensor of this type and use of a sensor of this type

Abstract

A sensor for detecting electrically conductive and/or polarizable particles, in particular for detecting soot particles, includes a substrate and at least two electrode layers, a first electrode layer and at least one second electrode layer. Which is arranged between the substrate and the first electrode layer. At least one insulation layer is formed between the first electrode layer and the at least one second electrode layer and at least one opening is formed in both the first electrode layer and the at least one insulation layer. At least some sections of the opening in the first electrode layer and of the opening in the insulation layer are arranged one above the other, such that at least one passage is formed to the second electrode layer.

1 .- 43 . (canceled) 
     
     
         44 . A sensor for detecting soot particles, the soot particles being electrically conductive or polarizable, the sensor comprising:
 substrate,   a first electrode layer and a second electrode layer, the second electrode layer arranged between the substrate and the first electrode layer;   a first insulation layer disposed between the first electrode layer and the second electrode layer;   a first opening disposed in the first electrode layer and a second opening disposed in the first insulation layer;   wherein the first opening and the second opening are aligned to form a first passage to the second electrode layer.   
     
     
         45 . The sensor as claimed in  claim 44 ,
 further comprising
 a second insulation layer and a third electrode layer, the second insulation layer disposed between the first electrode layer and the third electrode layer, 
 a third opening disposed in the third electrode layer and a fourth opening disposed in the second insulation layer, and 
   wherein the third opening and the fourth opening are aligned to form a passage extension to the first passage to the second electrode layer.   
     
     
         46 . The sensor as claimed in  claim 44 ,
 wherein the first opening is distal from a peripheral region of the first electrode layer and the second opening is distal from a peripheral region of the first insulation layer, and   wherein the third opening is distal from a peripheral region of the third electrode layer and the fourth opening is distal from a peripheral region of the second insulation layer.   
     
     
         47 . The sensor as claimed in  claim 45 ,
 wherein the first electrode layer, the second electrode layer, or the third electrode layer comprises a metal, a metal alloy, a high-temperature-resistant metal, a high-temperature-resistant alloy, a platinum metal, or an alloy of a metal of the platinum metals.   
     
     
         48 . The sensor as claimed in  claim 45 ,
 wherein the first electrode layer comprises a first material selected from the group of a metal, a metal alloy, a high-temperature-resistant metal, a high-temperature-resistant alloy, a platinum metal, or an alloy of platinum metals,   wherein the second electrode comprises a second material selected from the group of a metal, a metal alloy, a high-temperature-resistant metal, a high-temperature-resistant alloy, a platinum metal, or an alloy of platinum metals,   wherein the third electrode comprises a third material selected from the group of a metal, a metal alloy, a high-temperature-resistant metal, a high-temperature-resistant alloy, a platinum metal, or an alloy of platinum metals, and   wherein the second material has a higher etching resistance than the first material or the third material.   
     
     
         49 . The sensor as claimed in  claim 44 , further comprising a covering layer disposed on a side of the first electrode layer, the side of the first electrode layer facing away from the first insulation layer, the covering layer comprising ceramic, a glass, a metal oxide, or a combination thereof. 
     
     
         50 . The sensor as claimed in  claim 45 ,
 further comprising a covering layer disposed on a side of the third electrode layer, the side of the third electrode layer facing away from the first insulation layer, the covering layer comprising ceramic, a glass, a metal oxide, or a combination thereof,   wherein the first passage is a blind hole,   wherein a portion of the second electrode layer is a bottom of the blind hole, and   wherein the blind hole extends through the first insulation layer, the first electrode layer, the second insulation layer, the third electrode layer, or the covering layer.   
     
     
         51 . The sensor as claimed in  claim 50 , wherein
 the blind hole has a square cross section with a surface area in a range of 3×3 μm 2 -150×150 μm 2 , a range of 10×10 μm 2 -100×100 μm 2 , a range of 15×15 μm 2 -50×50 μm 2 , or 20×20 μm 2 .   
     
     
         52 . The sensor as claimed in  claim 44 ,
 further comprising a fifth opening disposed in the first electrode layer and a sixth opening disposed in the first insulation layer,   wherein the fifth opening and the sixth opening are aligned to form a second passage to the second electrode layer,   wherein the first passage is a first blind hole having a first cross-sectional area,   wherein the second passage is a second blind hole having a second cross-sectional area, and   wherein the first cross-sectional area is larger than the second cross-sectional area.   
     
     
         53 . The sensor as claimed in  claim 45 , wherein the first passage, the passage extension, or a combination of the first passage and the passage extension comprises a meandering shape or a spiral shape. 
     
     
         54 . The sensor as claimed in  claim 53 ,
 further comprising a covering layer disposed on a side of the third electrode layer, the side of the third electrode layer facing away from the first insulation layer, the covering layer comprising ceramic, a glass, a metal oxide, or a combination thereof,   wherein the first passage is a blind hole,   wherein a portion of the second electrode layer is a bottom of the blind hole, and   wherein the blind hole extends through the first insulation layer, the first electrode layer, the second insulation layer, the third electrode layer, or the covering layer.   
     
     
         55 . The sensor as claimed in  claim 45 ,
 further comprising a covering layer disposed on a side of the third electrode layer, the side of the third electrode layer facing away from the first insulation layer, the covering layer comprising ceramic, a glass, a metal oxide, or a combination thereof,   wherein the first electrode layer comprises a first electrical contact area,   wherein the second electrode layer comprises a second electrical contact area,   wherein the third electrode layer comprises a third electrical contact area,   wherein the first electrical contact area is connected to the first electrode layer, the second electrical contact area is connected to the second electrode layer, the third electrical contact area is connected to the third electrode layer,   wherein the second electrical contact area is not overlayed by the first insulation layer and the first electrode layer,   wherein the first electrical contact area is not overlayed by the second insulation layer and the third electrode layer,   wherein the third electrical contact area is not overlayed by a covering layer, and   wherein each electrical contact area is connected to a terminal pad.   
     
     
         56 . The sensor as claimed in  claim 55 ,
 wherein the first electrode layer, the second electrode layer, or the third electrode layer comprises a strip conductor loop, strip conductor loop being a heating coil, a temperature-sensitive layer, a shielding electrode, or a combination thereof,   wherein the first electrode layer, the second electrode layer, or the third electrode layer comprising the strip conductor loop comprises further a fourth electrical contact area not overlayed by one of the insulation layers or an electrode layer, and   wherein the fourth electrical contact area is connected to the terminal pad.   
     
     
         57 . A sensor system comprising:
 the sensor of  claim 45 , and   a controller or a control circuit, the controller or the control circuit for operating the sensor in a measuring mode, in a cleaning mode, in a monitoring mode, or a combination thereof.   
     
     
         58 . A method for controlling the sensor as claimed in  claim 45 , the method comprising the step of:
 operating the sensor in a measuring mode, in a cleaning mode, in a monitoring mode, or a combination thereof.   
     
     
         59 . A method of making a sensor for detecting soot particles, the soot particles being electrically conductive or polarizable, the sensor comprising
 a substrate;   a first electrode layer and a second electrode layer, the second electrode layer arranged between the substrate and the first electrode layer;   a first insulation layer disposed between the first electrode layer and the second electrode layer;   a second insulation layer and a third electrode layer,   a third opening disposed in the third electrode layer and a fourth opening disposed in the second insulation layer, and   wherein the third opening and the fourth opening are aligned to form a passage extension to the first passage to the second electrode layer,   the method comprising the steps of:   laminating the first electrode layer, the second electrode layer, the third electrode, the first insulation layer, and the second insulation layer to form a laminate, the first insulation layer being disposed between the first electrode layer and the second electrode layer, the second insulation layer disposed between the first electrode layer and the third electrode layer,   subsequently forming a passage through the first electrode layer, the third electrode layer, the first insulation layer, and the second insulation layer,   ending the passage to have a bottom formed by a portion of the second electrode layer.   
     
     
         60 . The method as claimed in  claim 59 ,
 wherein the passage is formed as a blind hole by etching, plasma-ion etching, or successive etching adapted to each layer being etched.   
     
     
         61 . The method as claimed in  claim 60 ,
 wherein the passage is formed as a blind hole or as an elongate depression by etching, plasma-ion etching, or successive etching adapted to each layer being etched, and   wherein the first insulation layer or the second insulation layer is etching-resistant layer, the blind hole or a portion of the elongate depression being formed in the insulation layer by a conditioning process with phase conversion of the first insulation layer or the second insulation layer.   
     
     
         62 . The method as claimed in  claim 59 ,
 wherein the passage is formed as a blind hole, a subportion of the blind hole, an elongate depression, or a subportion of the elongate depression by irradiation,   wherein irradiation is performed with electromagnetic waves, charged particles, or electrons,   wherein a radiation source, a wavelength, a pulse frequency of a radiation, or energy of the charged particles being adapted individually to each layer being irradiated.   
     
     
         63 . A method of making a sensor for detecting soot particles, the soot particles being electrically conductive or polarizable, the sensor comprising
 a substrate;   a first electrode layer and a second electrode layer, the second electrode layer arranged between the substrate and the first electrode layer;   a first insulation layer disposed between the first electrode layer and the second electrode layer;   a second insulation layer and a third electrode layer,   a third opening disposed in the third electrode layer and a fourth opening disposed in the second insulation layer, and   wherein the third opening and the fourth opening are aligned to form a passage extension to the first passage to the second electrode layer, the method comprising the steps of:   laminating the first electrode layer, the second electrode layer, the third electrode, the first insulation layer, and the second insulation layer to form a laminate, the first insulation layer being disposed between the first electrode layer and the second electrode layer, the second insulation layer disposed between the first electrode layer and the third electrode layer,   wherein the first electrode layer, the second electrode layer, the third electrode, the first insulation layer, or the second insulation layer are structured by a lift-off process, an ink-jet process, a stamping process one over the other forming a passage to the second electrode layer.   
     
     
         64 . A method of using the sensor of  claim 45 , the method comprising the step of:
 directing a flow (a) of the soot particles to not impinge perpendicularly on a plane (x, y) of the third electrode.   
     
     
         65 . A method of using the sensor of  claim 56 , the method comprising the step of:
 detecting electrically conductive or polarizable particles, and   adjusting an angle α between a normal (z) to a plane (x, y) of the first electrode layer and a direction of a flow (a) of the particles is 1 degree or more, 10 degrees or more, or 30 degrees or more.