WO2013029824A1 - Élément détecteur pour la détermination d'au moins une propriété d'un gaz dans une chambre de gaz de mesure - Google Patents

Élément détecteur pour la détermination d'au moins une propriété d'un gaz dans une chambre de gaz de mesure Download PDF

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Publication number
WO2013029824A1
WO2013029824A1 PCT/EP2012/061738 EP2012061738W WO2013029824A1 WO 2013029824 A1 WO2013029824 A1 WO 2013029824A1 EP 2012061738 W EP2012061738 W EP 2012061738W WO 2013029824 A1 WO2013029824 A1 WO 2013029824A1
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WIPO (PCT)
Prior art keywords
heating
sensor element
heating element
region
maximum
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PCT/EP2012/061738
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German (de)
English (en)
Inventor
Jens Schneider
Lothar Diehl
Sascha Klett
Gerhard Schneider
Original Assignee
Robert Bosch Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by Robert Bosch Gmbh filed Critical Robert Bosch Gmbh
Priority to CN201280041274.4A priority Critical patent/CN103748460A/zh
Publication of WO2013029824A1 publication Critical patent/WO2013029824A1/fr

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/403—Cells and electrode assemblies
    • G01N27/406—Cells and probes with solid electrolytes
    • G01N27/4067—Means for heating or controlling the temperature of the solid electrolyte

Definitions

  • Sensor element for detecting at least one property of a gas in a sample gas space
  • a large number of sensor elements and methods for detecting at least one property of a gas in a measuring gas space are known from the prior art.
  • these can be any physical and / or chemical properties of the gas, one or more properties being able to be detected.
  • the invention is described below in particular with reference to a qualitative and / or quantitative detection of a gas component of the gas, in particular with reference to a detection of an oxygen content in the gas.
  • the oxygen content can be detected, for example, in the form of a partial pressure and / or in the form of a percentage. Alternatively or additionally, however, other properties of the gas can be detected.
  • such sensor elements can be configured as so-called lambda probes, as they are known, for example, from Konrad Reif (ed.): Sensors in
  • broadband lambda probes in particular with planar broadband lambda probes, for example, the
  • the air ratio lambda describes this air-fuel ratio.
  • ceramic sensor elements are known from the prior art, which are based on the use of electrolytic properties of certain solids, that is to ion-conducting properties of these solids.
  • these solids can be ceramic solid electrolytes, such as
  • zirconia in particular yttrium-stabilized zirconia (YSZ) and / or scandium-doped zirconia (ScSZ), which may contain small amounts of aluminum oxide (Al 2 O 3 ) and / or silicon oxide (Si0 2 ).
  • the lambda probe Due to its measuring principle, the lambda probe usually has to be first heated to its operating temperature, since the solid electrolyte becomes conductive only at temperatures above 350 ° C. for oxygen ions.
  • the operating temperature is
  • DE 35 38 460 A1 discloses an oxygen sensor element for a motor vehicle with a sensor unit and a heating unit. Due to its use in a motor vehicle, the oxygen element has a length of 50 mm to 80 mm and a width of 4 mm to 7 mm.
  • the sensor unit comprises a solid electrolyte body with reference and measuring electrodes and conductors formed thereon.
  • the heating unit comprises a heating area arranged on a ceramic substrate in the form of a heating element
  • Resistance heating element and a pair of the resistance heating element outgoing conductor whose resistance is smaller than that of the resistance heating element.
  • Lambda sensors for motor vehicles, especially automobiles, and commercial vehicles have a comparatively large heating element with a high power consumption.
  • a low-impedance, high-performance heater, as used in such lambda probes would be too large for small motor vehicles and problematic due to the additional cost of a high-performance heater output stage and for heat-effective heat dissipation from the controller. Disclosure of the invention
  • the sensor element according to the invention for detecting at least one property of a gas in a gas space in particular for detecting a gas component in the gas or for detecting a temperature of the gas, can have at least one
  • Solid electrolyte, at least one arranged on or in the solid electrolyte electrode, and at least one heating element for heating the solid electrolyte include.
  • the heating element can have at least one supply area and a
  • Heating range wherein the supply line has a cold resistance, which is not more than 30%, preferably not more than 25% and particularly preferably not more than 16%, a total cold resistance of the heating element.
  • the heating element can have a total cold resistance of 6 ohms to 22 ohms,
  • the heating element may be an electrical heating element with a power consumption of a maximum of 5 W, preferably a maximum of 4 W and particularly preferably a maximum of 3.5 W, at an operating voltage of 13 V.
  • the sensor element may have a maximum length of 50 mm, preferably a maximum of 45 mm and particularly preferably a maximum of 35 mm, and a maximum width of 10 mm, preferably a maximum of 8 mm and particularly preferably a maximum of 4 mm, for example a length of 35 mm and a Width of 4 mm.
  • the heating element may comprise a heating conductor which has a smaller thickness and a smaller width in the heating region than in the supply region, for example a maximum thickness of 50% of the supply region thickness and / or a maximum width of 50% of the width of the supply region
  • the heat conductor may have a thickness of at most 16 ⁇ m, preferably not more than 12 ⁇ m and particularly preferably not more than 8 ⁇ m, and a maximum width of 300 ⁇ m, preferably not more than 250 ⁇ m and more preferably not more than 200 ⁇ m, for example a thickness of 8 ⁇ and a width of 200 ⁇ .
  • the heating conductor may be meander-shaped in the heating area and comprise at least five meander turns.
  • the heating conductor may be formed meandering in the heating area such that the conductor sections forming the meandering are arranged mirror-symmetrically to a center plane and the distance of those conductor sections to each other on each side of the median plane parallel to the
  • the heating element may be made of a metal cermet or metal alloy cermet, and the metal or at least one metal of the metal alloy may be selected from the group of platinum group metals.
  • the metal alloy cermet may comprise a metal alloy containing alumina.
  • the heating element may be configured such that a manufacturing tolerance of the resistor in the
  • Heating range and / or the supply range is less than 10%.
  • a solid electrolyte is to be understood as meaning a body or article having electrolytic properties, that is to say having ion-conducting properties.
  • it may be a ceramic solid electrolyte.
  • This also includes the raw material of a solid electrolyte and therefore the formation as a so-called green or brown, which only after a sintering to a
  • Solid electrolyte is.
  • the solid electrolyte may be formed as a solid electrolyte layer or of a plurality of solid electrolyte layers.
  • a layer is to be understood as meaning a uniform mass in a planar extent at a certain height, which lies above, below or between other elements.
  • an electrode in the context of the present invention is generally to be understood as meaning an element which is capable of contacting the solid electrolyte in such a way that a current can be maintained by the solid electrolyte and the electrode.
  • the electrode may comprise an element to which the ions can be incorporated in the solid electrolyte and / or removed from the solid electrolyte.
  • the electrodes comprise a noble metal electrode, which may, for example, be applied to the solid electrolyte as a metal-ceramic electrode or otherwise be in communication with the solid electrolyte.
  • Typical electrode materials are platinum cermet electrodes. However, other precious metals, such as gold and / or palladium, are in principle applicable. Together with a solid electrolyte, the electrode or the electrodes can form a measuring cell of a sensor element, such as a lambda probe.
  • a heating element is generally to be understood as meaning an element which is capable of heating the solid electrolyte and the electrodes to their functional temperature.
  • the heating element can a
  • a heating region of the heating element is to be understood as that region of the heating element which overlaps the electrode in the direction of this layer structure.
  • the heating region of a heating element is that region which overlaps with the actual measuring cell of the lambda probe.
  • a lateral supernatant, i. a protrusion in the width direction, the heating area via the electrode or the electrodes also belongs to the heating area. For example, in a planar structure of a lambda probe, the overlap in a direction perpendicular to the planar structure can be seen.
  • the heating area is usually located in an end region of the solid electrolyte.
  • a supply region is to be understood as that region of the heating element which serves to transport the energy for heating the solid electrolyte and the electrode into the heating region.
  • a cold resistance in the context of the present invention is to be understood as the electrical resistance measured at 20 ° C.
  • the total cold resistance is understood to mean the electrical resistance of the entire heating element, which is composed of the resistance of the heating region and the resistance of the supply region.
  • a manufacturing tolerance is to be understood as meaning the state of a system in which a deviation from the normal state caused by an interfering action, such as, for example, a production-related deviation, does not exist
  • manufacturing tolerance is the extent of deviation of a size of the standard state or standard size, which just does not endanger the function of a system. Therefore, manufacturing tolerance of the resistor is a production-related deviation of the resistance of the setpoint specified in the production, which does not lead to a significant and unacceptable change in function.
  • Resistors for one Inventive heating element within the manufacturing tolerance thus have an identical heating behavior or a similar heating behavior with a deviation that do not change the function of the sensor element during operation so that it comes to damage, unpredictable behavior or uselessness.
  • the deviation may be in adjacent sections or areas of the heat conductor or even at the molecular level of the components of the heat conductor from each other, such as within a cross-sectional surface section of the heat conductor.
  • a 10% fabrication tolerance means that there are areas or locations in the heat conductor that are above or below 10% of other areas or locations of the heat conductor. If 8 ohms are specified as the setpoint for the heating conductor, for example in the heating area, then there is no point in the heating area which has a resistance of less than 7.9 ohms or greater than 8.1 ohms.
  • the platinum metal group according to the general definition of chemistry is the elements of groups 8 to 10 of the 5th period, ie the light platinum metals ruthenium (Ru), rhodium (Rh), palladium (Pd), and 6. Period, ie the heavy platinum metals osmium (Os), iridium (Ir), platinum (Pt) to understand.
  • percolation describes the formation of contiguous regions (clusters) by randomly occupying structures (lattices).
  • lattice points become a particular
  • the occupation probability is defined as the value at which at least one cluster reaches a size that extends through the entire system, eg has an extension on a two-dimensional grid from the right to the left or from the upper to the lower side. It is said that the cluster percolates through the system. This value of
  • Occupancy probability is the so-called percolation threshold.
  • the invention is fundamentally suitable for any internal combustion engine which has at least one ceramic sensor element for detecting at least one parameter of an exhaust gas of an internal combustion engine, in particular at least one lambda sensor and / or at least one NOx sensor and / or at least one HC sensor the ceramic sensor element has at least one heating element for heating the ceramic sensor element.
  • the internal combustion engine may comprise a gasoline engine and / or a diesel engine.
  • the internal combustion engine may also comprise a hybrid drive, for example with at least one gasoline engine and / or at least one diesel engine and additionally at least one electric motor.
  • the ceramic sensor element may in particular be a lambda probe or comprise a lambda probe.
  • the lambda probe can be designed, for example, as a finger probe or as a planar lambda probe, that is to say for example as a lambda probe with a laminar structure.
  • jump probes and / or broadband lambda probes can be realized.
  • the ceramic substrate may in particular be a lambda probe or comprise a lambda probe.
  • the lambda probe can be designed, for example, as a finger probe or as a planar lambda probe, that is to say for example as a lambda probe with a laminar structure.
  • jump probes and / or broadband lambda probes can be realized.
  • Sensor element also comprise at least one other type of ceramic sensor element, for example, a NOx sensor.
  • the ceramic sensor element may comprise at least one electrochemical cell.
  • an electrochemical cell is to be understood as meaning an element which comprises at least two electrodes and at least one solid electrolyte which connects the electrodes.
  • a temperature of the ceramic sensor element can, for example, by means of a determination of a
  • Sensor element can be detected for example by means of a determination of the internal resistance of the Nernst cell.
  • Such an electrochemical cell can thus serve as a measuring cell for the sensor element.
  • the heating of the ceramic sensor element and / or the power supply of the heating element can be effected by means of an electrical energy source, such as the battery in a vehicle.
  • the heating element according to the invention differs fundamentally from a
  • Heating element for lambda probes for motor vehicles can basically be realized as a co-sintered or subsequently sintered platinum-metal group structure.
  • the heating element is a weak heating element for bridging cold operating conditions, such as during a
  • Idling with a maximum power consumption of 5 W, while lambda probes for motor vehicles more than 7 W are usual.
  • the inrush current does not exceed 2 A to minimize the requirement for a sensor element controller.
  • a light-emitting behavior of the probe of up to 30 seconds is unproblematic for exhaust gas probes for small motor vehicles, since the majority of the pollutant amount is not formed here in the starting phase, but within the corresponding driving cycle.
  • the use of metals of the platinum group metal for the structure of the heating element is due to the high thermal load of hot exhaust gases, which may be up to about 1000 ° C at full load required.
  • the heating element is formed in particular from platinum cermet and may correspond to the material composition of the prior art, but is designed with a high support framework share and thin meander and lead structures, for example, to a total cold resistance of 8 ohms to 20 ohms. It suffices in this case to design the heating power in such a way that, when heating in a cold ambient temperature, ie at temperatures from -20 ° C to -40 ° C, a sensor element temperature of at most 750 ° C is reached.
  • a sensor element with a maximum length of 35 mm and a maximum width of 4 mm which has an integrated heating element which has a minimum cold resistance at 20 ° C of 8 to 20 ohms and a
  • the heating element is designed so that the majority of the resistance lies in the meander.
  • the supply line is designed to be 1, 0 ohms and the meander to 8 ohms. This gives a
  • Meander resistance is realized by a small layer thickness of maximum 8 ⁇ m and a small track width of 200 ⁇ m.
  • the ratio is designed so that for meander thickness and meander width, the relative thickening fluctuation is equally small, i. below 10%.
  • the minimum layer thickness may be 10 ⁇ m, for a lateral variation in thickness of the heating element of 20 ⁇ m, the minimum width may not be less than 200 ⁇ m.
  • an additional Guranderpipee is installed and the entire length of the heating element is 15 mm.
  • the outer meander turns closer merged to achieve a high meandering hot resistance by the heating.
  • the meander paste can with a higher alumina scaffolding share of
  • Clumps of the scaffold should not be greater than 10%. Therefore, an extremely fine alumina powder in which at least 50% of the powder particles have a
  • Grain diameter of less than 500 nm have to use. This will
  • the meander paste is alloyed with 20% by volume of palladium or another metal of the platinum group metal.
  • the uniformity of the alloy through the use of intensive pre-grinding is so well designed that the local
  • Resistance fluctuation remains below 10%.
  • a small proportion of up to 3% of a sintering aid such as phosphorus, silicon, bismuth or a dense sintering ternary alloy is used, as used for example in DE 198 34 276 A1.
  • a sintering aid such as phosphorus, silicon, bismuth or a dense sintering ternary alloy.
  • the premilling of platinum, metals of the platinum group metal and the scaffold takes place in a common process step.
  • the heater insulation and the supply line can be tight sintered to prevent evaporation of the palladium and thus a short circuit of the insulation.
  • the supply line can also be designed with a higher resistance than 3 ohms in order to further reduce the use of the board and thus the cost of the heating element.
  • the corners of the layout are made round to reduce local resistance maxima that remain colder.
  • the heating element is produced in the 45 ° -shreshing process to the screen printing parameters and Paste dependence and thus reduce the resistance variations between transverse and longitudinal lying in the layout meandering.
  • Fig. 1 is a cross-sectional view of a sensor element
  • Fig. 2 is a plan view of a heating element of a sensor element of a first
  • Fig. 3 is a plan view of a heating element of a sensor element of a second
  • Fig. 4 is a plan view of a heating element of a sensor element of a third
  • Fig. 5 is a plan view of a heating element of a sensor element of a fourth
  • FIG. 6 is a schematic plan view of an exemplary heating element
  • Fig. 8 is an illustration of a voltage difference of a heating element with a
  • 9 shows a representation of the current density of the heating element with a cold resistance of 3 ohms in the heating area
  • 10 is an illustration of a voltage difference of a heating element with a cold resistance of 9 ohms in the heating area
  • Fig. 1 1 is a representation of the current density of the heating element with a cold resistance of 9 ohms in the heating area.
  • Figure 1 shows a cross-sectional view of a first embodiment of a
  • Sensor element 10 can be used for the detection of physical and / or chemical properties of a gas, wherein one or more properties can be detected.
  • the invention is described below in particular with reference to a qualitative and / or quantitative detection of a gas component of the gas, in particular with reference to a detection of an oxygen content in the gas.
  • the oxygen content can be detected, for example, in the form of a partial pressure and / or in the form of a percentage.
  • other types of gas components are detectable, such as nitrogen oxides, hydrocarbon and / or hydrogen.
  • other properties of the gas can be detected.
  • the invention can be used in particular in the field of vehicle technology, in particular in the field of small motor vehicles, such as
  • the sensor element 10 therefore has, for example, a length, i. a dimension in the viewing direction of Figure 1 of a maximum of 50 mm, preferably maximum
  • the sensor element 10 for example, a length of 35 mm and a width of 4 mm.
  • the sensor element 10 is described as an exemplary component of a planar lambda probe, but is not limited in this way to lambda probe, but may also be designed as a finger probe. Therefore, the cross-sectional view of FIG. 1 is a view seen in a longitudinal direction of the sensor element 10.
  • the sensor element 10 comprises a solid electrolyte 12 containing yttrium stabilized zirconia first electrode 14, a second electrode 16, a heating element 18 and a reference channel 20.
  • a pumped reference can be problematic for small motor vehicles, which is why in the example shown a
  • Probe design with air reference and corresponding effect on a low heating power demand is strongly preferred.
  • a high heating power is at the
  • the heating element 18 is arranged to heat the electrodes 14, 16 and the solid electrolyte.
  • the electrodes 14, 16 are connected to one another via the solid electrolyte 12 and can form a Nernst cell and / or electrochemical cell.
  • further functional layers for example further electrodes, a conductor track, a diffusion barrier, a diffusion gap, a further heating element and / or an oxygen pumping cell. These functional layers can be incorporated or integrated in the solid electrolyte.
  • the optional Nernst cell in the solid electrolyte layer is preferably provided to measure in a combustion exhaust gas the respective residual oxygen content in order to calculate the ratio of
  • FIG. 2 shows a plan view of a first embodiment of a sensor element 10 according to the invention, in particular its heating element 18.
  • the sensor element 10 of the lambda probe is, for example, a sensor element 10 of a planar lambda probe.
  • the heating element 18 has a
  • Heating conductor 22 with a supply line 24, which is located in the illustration in Figure 2 right in the image, and with a heating region 26, which is in the illustration of Figure 2 on the left in the image on.
  • the heating element 18 may in particular be insulated in the
  • the heating region 26 of the heating element 18 is meander-shaped and has three meander turns 28.
  • the corners of the meander turns 28 may be rounded.
  • the heating element 18 is designed such that the supply region 24 has a cold resistance which is not more than 30% of a total cold resistance of the heating element 18, preferably not more than 25% and especially preferably not more than 16%.
  • the cold resistance of the heating element 18 is not more than 30% of a total cold resistance of the heating element 18, preferably not more than 25% and especially preferably not more than 16%.
  • Lead area 24 does not exceed 12% of the total cold resistance of the
  • the total cold resistance of the heating element 18 may be, for example, 9 ohms for an application of the sensor element 10 in a motorcycle.
  • the feed line 22 in this example has a resistance of 1 ohm and the heating region 26 has a resistance of 8 ohms.
  • the heating element 18 is formed of an alloy containing at least one element of the platinum group metal.
  • the alloy for the heating element 18 may include platinum.
  • the use of elements of the platinum group of metals for the heating element 18 may be required because of high thermal stress from hot exhaust gases, which at full load may have a temperature of about 1000 ° C. To the board use and thus the manufacturing cost of
  • the supply region 24 also has a higher cold resistance, such as 3 ohms.
  • the total cold resistance of the heating element 18 can then be 1 1 ohms.
  • the use of a platinum cermet or a cermet with another element of the platinum group metal is also possible.
  • the heating element 18 is thus designed so that it has a power consumption of not more than 5 W, preferably not more than 4 W and particularly preferably not more than 3.5 W, for bridging cold operating states, for example during idling, at an operating voltage of 13 V.
  • the current to activate the heating element 18, i. the so-called inrush current does not exceed 2 A in order to meet the requirement for a control unit, not shown, with regard to the
  • the heating conductor 22 may have a smaller thickness and a smaller width in the heating region 26 than in the supply region 24, such as a thickness of at most 50% of the thickness of the supply region 24 and / or a maximum width of 50% of the width of the supply region 24.
  • the heating conductor 22 may in the heating region 26, for example, a thickness of at most 16 ⁇ , preferably at most 12 ⁇ and more preferably at most 8 ⁇ , and a maximum width of 300 ⁇ , preferably at most 250 ⁇ and more preferably at most 200 ⁇ have, for example one Thickness of 8 ⁇ and a width of 200 ⁇ .
  • FIG. 3 shows a plan view of a second embodiment of a sensor element 10 according to the invention, in particular its heating element 18 only the differences from the first embodiment described, wherein like components have the same reference numerals.
  • the sensor element 10 also has a heating element 18.
  • the heating element 18 has two additional meander turns 28 in the heating area 26 compared to the heating element 18 of the first embodiment.
  • the heating element 18 thus has in the
  • Heating area 26 a total of five meander 28 on.
  • the heating conductor 22 has a smaller thickness and width in the heating region 26 than in the first embodiment.
  • the heating conductor 22 may in the heating region 26, for example, a maximum thickness of 10 ⁇ , preferably at most 8 ⁇ , and a maximum width of 200 ⁇ , preferably at most 175 ⁇ , for example, have a thickness of 7 ⁇ and a width of 170 ⁇ .
  • the heating conductor 22 may be formed, for example 15 mm long. Thereby, a higher hot resistance than in the first embodiment, i. a resistance measured at a temperature of 750 ° C, can be achieved, for example, from a resistance of 2 ohms in the supply region 24 and from 32 ohms in the
  • FIG. 4 shows a plan view of a third embodiment of a sensor element 10 according to the invention, in particular on the heating element 18. Only the differences from the second embodiment will be described below, wherein like components have the same reference numerals.
  • the outer meander turns 28 are brought closer together in comparison with the second embodiment of FIG. 3 in order to achieve an even higher hot resistance by the heating.
  • the conductor sections which form the meander turns 28 are arranged mirror-symmetrically in the heating region 26 to an imaginary center plane in the longitudinal direction, wherein the distance between those conductor sections 30 which are parallel to each other on each side of the median plane
  • FIG. 5 shows a plan view of a fourth embodiment of a sensor element 10 according to the invention, in particular its heating element 18 only the differences from the second and third embodiments described, wherein like components have the same reference numerals.
  • the outer meander turns 28 are brought closer together in comparison with the second embodiment of FIG. 3 in order to achieve an even higher hot resistance by the heating.
  • the conductor sections which form the meander turns 28 are arranged mirror-symmetrically in the heating region 26 to an imaginary center plane in the longitudinal direction, wherein the distance between those conductor sections 30 which are parallel to each other on each side of the median plane
  • the distance between the respective two conductor portions 30 having the largest distance to the center plane on each side of the center plane is smaller.
  • the distance between the conductor portions 30 that are closest to each other across the center plane is larger.
  • FIG. 6 shows a schematic plan view of a sensor element 10 according to the invention with an integrated heating element 18, which has a supply region 24 and a
  • Heating area 26 has.
  • the representation of FIG. 6 serves to explain the
  • the heating element 18 has two connection contacts 32, which can be seen in the right-hand edge of the picture, and are provided for connection to an electrical energy source (not shown).
  • An operating voltage of 13 V can be applied to the connection contacts 32 in order to heat the solid electrolyte 12 and the electrodes 14, 16.
  • FIG. 6 also shows that the heating conductor 22 is made wider in the supply region 24 than in the supply region 24
  • FIG. 7 shows the temperature distribution of the heating element 18 of FIG. 6 in the region of the electrode 14 and its arrangement on the solid electrolyte 12 in the operating state, ie the heated state.
  • the electrode 14 has two connection contacts 34, which can be seen in the right-hand edge of the picture, and are provided for connection to an electrical energy source (not shown).
  • an electrode lead 36 of the electrode 14 may be arranged so that the electrode lead, projected into a plane of the heating element 18, is located between the conductor portions of the lead region 24.
  • the temperature in the heating region 26 which overlaps with the electrode 14 is significantly higher than in the supply region 24.
  • FIG. 8 shows an exemplary distribution of the voltage difference between the
  • Heating element 18 during operation As the illustration shows, one becomes
  • Terminal contact 32 is applied, in particular while the heating element 18 is designed such that it has a cold resistance of approximately 2.7 ohms in the heating area.
  • FIG. 9 shows an exemplary distribution of the current density between the
  • the area size for indicating the current density refers to a cross-sectional area of the heating conductor 22. As can be seen from the illustration of FIG. 9, the current density in the meandering heating area 26 is highest and increases the supply line 24 towards strongly. The values of the current density of this example are shown in the scale on the left in the image of FIG.
  • FIG. 10 shows another exemplary distribution of the voltage difference between the terminal contacts 32 of the heating element 18 in mV in a plan view of FIG
  • Heating element 18 during operation As the illustration shows, one becomes
  • Terminal contact 32 is applied, in particular while the heating element 18 is designed such that it has a cold resistance of approximately e ohms in the heating region.
  • the distribution of the voltage difference during operation of the heating element 18 is identical to the distribution of the example of FIG. 8 and thus does not change by a change in resistance.
  • Figure 1 1 shows an exemplary distribution of the current density between the
  • the area size for indicating the current density refers to a cross-sectional area of the heating element 22.
  • the current density in the meandering heating region 26 is highest and decreases toward the supply region 24 towards strongly.
  • the values of the current density of this example are shown in the scale on the left in the image of FIG. Compared with the current density of the heating element 18 of Figure 9, this is significantly lower in the example of Figure 1 1.
  • the heating area 26 of the heating element 18 of FIG. 11 will heat up more than the heating element 18 of FIG. 9.
  • a sensor element such as a planar
  • Lambda probe various manufacturing methods are known, such as the film, the thin-film or the thick-film technology. Therefore, these are not discussed in detail, but it will be the deviations from the conventional
  • the heating element 18 may in the known layer structure by, for example
  • a starting material such as a paste
  • the proportion of aluminum oxide in the paste may be, for example, 25% by volume. This provides a higher resistance.
  • the paste can be applied so that this higher resistance is provided in certain areas of the heating element 18, in particular in the heating area 26. Due to the higher resistance in the heating area 26, the Heating power can be concentrated on specific areas of the heating element 18, in this example, the heating area 26. Thus, for example, the heating power of the
  • Heating element 18 almost completely, such as 94% discharged in the heating region 26, while the supply region 24 is heated only slightly. It should be mentioned at this point that aluminum oxide has an electrically insulating effect, so that the resistance increases with increasing proportion of aluminum oxide.
  • a very fine alumina powder can be used. Under a very fine
  • aluminum oxide powder is a powder in which at least 50% of the particles have a diameter of less than 500 nm. This will be the
  • Alumina powder preferably before paste processing in one
  • Alumina powder comes.
  • the premilling of platinum, another metal of the platinum group metal and the scaffold, such as the alumina, can be done in a common process step to increase the mixing or distribution of these ingredients.
  • the heating element 18 is designed such that the local resistance variation, i. the manufacturing tolerance of the resistors, is reduced by the proportion of alumina in the paste is chosen so that it is 3 vol .-% below the percolation threshold, in which the dependence on the proportion of aluminum oxide is extremely large.
  • the percolation threshold describes the
  • Thickness direction is formed by the heating conductor continuously extending or connected alumina area or cluster or more such interconnected alumina areas or clusters are formed. Since, as already mentioned, the aluminum oxide has an electrically insulating effect, the achievement or exceeding of the percolation threshold would lead to an extremely large increase in the resistance. During the operation of the heating element 18, this could lead to an uneven distribution of the heating power and / or even to an at least partial overheating of the electrodes 14, 16 and / or the solid electrolyte 12. Without the use of such a fine alumina powder so local resistance centers could be caused to become the so-called hot spots during operation, so points with very high temperature, which are the starting point for the aging of the heating element 18.
  • the paste for the production of the heating element can be alloyed with 20% by volume of palladium or another metal of the platinum metal group. It is important to ensure a uniformity of the alloy, which can be achieved for example by using an intensive Vormahlung.
  • a further increase in the cold resistance can be achieved, for example, by a small proportion of not more than 3% by volume of a sintering aid, for example phosphorus (P), silicon (Si), bismuth (Bi) and / or a dense sintering ternary alloy, ie Alloy of three elements, as disclosed for example in DE 198 34 276 A1.
  • the cold resistance can be increased and lower an initial power consumption, ie with the same electrical power can achieve a higher heat output or with a lower electrical power can achieve the same heating power.
  • a density-internal design of the heating element insulation and of the heating conductor 22 in the supply region 24 evaporation of the palladium during the sintering process and thus short-circuiting of the insulation can be avoided.
  • the supply area of the heating element 18 can also be designed with a higher resistance, such as 3 ohms, instead of the above-mentioned 1 ohms in order to further reduce the use of the board and thus the costs of the heating element 18.
  • the heating element 18 may be fabricated in two separate printing steps, which may be performed sequentially or simultaneously, using two pastes with different proportions of alumina to achieve the different resistances of the lead region 24 and the heating region 26.
  • the heating region 26 and the supply region 24 can be printed separately by screen printing on the solid electrolyte 12, wherein the paste for the heating region 26 has a higher proportion of aluminum oxide than the paste for the supply region 24.
  • the heating element 18 in the so-called 45 ° In order to reduce the screen printing parameters and paste dependence, and thus the resistance variations between in the width direction of the sensor element 10 and longitudinal conductor portions of the meandering heating region 26 to be made.
  • the heating element 18 By designing the heating element 18 in which corners of the design, such as the meandering sweep 28, are made round, areas of the heat conductor 22 that remain colder during operation can be reduced.
  • a higher resistance in the heating region 26 than in the supply region 24 can be achieved, for example, by a smaller thickness and / or width of the heating conductor 22 in the heating region 26 than in the supply region 24. This applies, for example, to the increase of the total cold resistance of the example of FIG.
  • the thickness and the width of the heating element 22 are formed in the heating region 26 with a relative manufacturing tolerance or deviation of less than 10%.
  • a manufacturing tolerance in the thickness direction within the heating element 18 of a maximum of 1 ⁇ therefore the minimum thickness 10 ⁇ not fall below and for a manufacturing tolerance in the width direction within the heating element 18 of a maximum of 20 ⁇ the minimum width 200 ⁇ not fall below
  • the abovementioned absolute values for production tolerance are to be regarded as maximum values, since the thickness of the heating conductor 22 in the heating region 26 is preferably 10 ⁇ m and the width of the heating conductor 22 in the heating region 26 is preferably not more than 200 ⁇ m.
  • the sensor element 10 has a heating element 18 made of a cermet, in particular a platinum cermet, which can be sintered together with the solid electrolyte 12 and the other functional layers.
  • a heating element 18 made of a cermet, in particular a platinum cermet, which can be sintered together with the solid electrolyte 12 and the other functional layers.
  • Heating element 18 of known sensor elements for automobiles and commercial vehicles by at least one of the following details.
  • the cross-sectional area of the heating conductor in the heating area and / or the supply area is lower.
  • the ratio of the resistances of the heating region and the supply region to the total resistance of the heating element is different, since the supply region occupies a small proportion of the total resistance. More or thinner meander turns are planned.
  • the scaffold portion of alumina and / or zirconia in the cermet, especially the platinum cermet, is higher. There will be more metals of the
  • Platinum metal group in the cermet in particular the platinum cermet provided.

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Abstract

L'invention concerne un élément détecteur (10) pour la détermination d'au moins une propriété d'un gaz dans une chambre de gaz, en particulier pour établir la présence d'un composant gazeux dans le gaz ou pour déterminer une température du gaz. L'élément détecteur (10) comprend au moins un électrolyte solide (12), au moins une électrode (14, 16), disposée sur ou dans l'électrolyte solide (12) et au moins un élément chauffant (18) pour le chauffage de l'électrolyte solide (12). L'élément chauffant (18) comporte au moins une zone d'alimentation (24) et une zone chauffante (26), la zone d'alimentation (24) présentant une résistance à froid qui n'est pas supérieure à 30 %, de préférence non supérieure à 25 % et de manière particulièrement préférée non supérieure à 16 % d'une résistance à froid globale de l'élément chauffant.
PCT/EP2012/061738 2011-08-26 2012-06-19 Élément détecteur pour la détermination d'au moins une propriété d'un gaz dans une chambre de gaz de mesure WO2013029824A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201280041274.4A CN103748460A (zh) 2011-08-26 2012-06-19 用于获取测量气体空间中气体的至少一个性能的传感器元件

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DE102011081629.1 2011-08-26
DE102011081629 2011-08-26

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WO2013029824A1 true WO2013029824A1 (fr) 2013-03-07

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9494548B2 (en) 2012-08-09 2016-11-15 Ngk Spark Plug Co., Ltd. Gas sensor
CN115785462A (zh) * 2022-11-02 2023-03-14 常州大学 Zr-PTC发光体材料、电化学发光传感器及其制备方法和应用

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102013211796A1 (de) * 2013-06-21 2014-12-24 Robert Bosch Gmbh Sensorelement mit Leiterbahn und Durchführung
DE102013212370A1 (de) * 2013-06-27 2014-12-31 Robert Bosch Gmbh Sensorelement zur Erfassung mindestens einer Eigenschaft eines Messgases in einem Messgasraum
FR3026179B1 (fr) * 2014-09-19 2018-02-16 Sc2N Sonde de mesure comportant un element sensible
DE102015203050A1 (de) * 2015-02-20 2016-08-25 Robert Bosch Gmbh Mikroheizvorrichtung für einen Sensor und Sensor
JP6382162B2 (ja) * 2015-07-08 2018-08-29 株式会社Ｓｏｋｅｎ ガスセンサのポンプ電極及び基準電極
DE102018215322A1 (de) * 2018-09-10 2020-03-12 Robert Bosch Gmbh Verfahren zum Test der Integrität einer gedruckten Leiterbahn
CN109765263B (zh) * 2018-12-28 2021-06-15 青岛青缆科技有限责任公司 一种用于制作地热电缆的加热装置

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3538460A1 (de) 1984-11-01 1986-04-30 Ngk Insulators Ltd Keramischer heizkoerper und verfahren zu seiner herstellung
DE3802051A1 (de) * 1987-01-27 1988-08-04 Ngk Insulators Ltd Einrichtung zur sauerstoffkonzentrationsermittlung
JPH0821813A (ja) * 1994-07-06 1996-01-23 Ngk Spark Plug Co Ltd センサ用セラミックヒータ及び酸素センサ
EP0963137A2 (fr) * 1998-06-05 1999-12-08 NGK Spark Plug Co. Ltd. Elément de chauffage en céramique et détecteur d'oxygène l'utilisant
DE19834276A1 (de) 1998-07-30 2000-02-10 Bosch Gmbh Robert Abgassonde
WO2005059535A1 (fr) * 2003-12-18 2005-06-30 Robert Bosch Gmbh Materiau ceramique composite lamellaire muni d'une couche d'electrolyte solide pouvant etre chauffee
JP2006337384A (ja) * 2001-08-30 2006-12-14 Kyocera Corp 酸素センサ

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4240812A1 (de) * 1992-12-04 1994-06-09 Bosch Gmbh Robert Heizeranordnung für einen Meßfühler zur Bestimmung von Bestandteilen in Gasen
DE102006053808B4 (de) * 2006-11-15 2021-01-07 Robert Bosch Gmbh Verfahren zur Bestimmung der Temperatur eines Messfühlers
JP4996527B2 (ja) * 2008-04-14 2012-08-08 日本特殊陶業株式会社 積層型ガスセンサ素子及びガスセンサ
CN101655474B (zh) * 2009-06-02 2013-10-30 中国原子能科学研究院 氧传感器电极铂浆的制备及烧结方法
CN102103118A (zh) * 2009-12-18 2011-06-22 中国电子科技集团公司第四十九研究所 一体式分压型氧气传感器的制造方法

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3538460A1 (de) 1984-11-01 1986-04-30 Ngk Insulators Ltd Keramischer heizkoerper und verfahren zu seiner herstellung
DE3802051A1 (de) * 1987-01-27 1988-08-04 Ngk Insulators Ltd Einrichtung zur sauerstoffkonzentrationsermittlung
JPH0821813A (ja) * 1994-07-06 1996-01-23 Ngk Spark Plug Co Ltd センサ用セラミックヒータ及び酸素センサ
EP0963137A2 (fr) * 1998-06-05 1999-12-08 NGK Spark Plug Co. Ltd. Elément de chauffage en céramique et détecteur d'oxygène l'utilisant
DE19834276A1 (de) 1998-07-30 2000-02-10 Bosch Gmbh Robert Abgassonde
JP2006337384A (ja) * 2001-08-30 2006-12-14 Kyocera Corp 酸素センサ
WO2005059535A1 (fr) * 2003-12-18 2005-06-30 Robert Bosch Gmbh Materiau ceramique composite lamellaire muni d'une couche d'electrolyte solide pouvant etre chauffee

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"Sensoren im Kraftfahrzeug", 2010, pages: 160 - 165

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9494548B2 (en) 2012-08-09 2016-11-15 Ngk Spark Plug Co., Ltd. Gas sensor
CN115785462A (zh) * 2022-11-02 2023-03-14 常州大学 Zr-PTC发光体材料、电化学发光传感器及其制备方法和应用
CN115785462B (zh) * 2022-11-02 2023-08-22 常州大学 Zr-PTC发光体材料、电化学发光传感器及其制备方法和应用

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