阅读说明：本技术 用于测定气体参数的传感器 (Sensor for determining gas parameters ) 是由 M·穆齐奥尔 T·艾斯慕斯 S·迭蒂曼 于 2018-05-03 设计创作，主要内容包括：本发明涉及一种传感器,特别是高温传感器,其具有至少一个全陶瓷加热器(3,3’)；和至少一个至少局部地布置在所述全陶瓷加热器(3,3’)的第一侧上的第一传感器结构(9)。本发明还涉及一种制造传感器的方法(1000)。(The invention relates to a sensor, in particular a high-temperature sensor, comprising at least one all-ceramic heater (3, 3'); and at least one first sensor arrangement (9) arranged at least partially on a first side of the all-ceramic heater (3, 3'). The invention also relates to a method (1000) of manufacturing a sensor.)

1. A sensor, in particular a high-temperature sensor, having:

at least one all-ceramic heater (3, 3'); and

at least one first sensor structure (9) arranged at least partially on a first side of the all-ceramic heater (3, 3').

2. Sensor according to claim 1, characterized in that the all-ceramic heater (3, 3') has:

at least one electrically conductive ceramic, which is preferably in contact with the electrodes (5a, 5a ', 5b, 5b') in at least two mutually separated positions, and

at least one electrically insulating ceramic, wherein the electrically insulating ceramic at least partially surrounds, preferably completely surrounds, the electrically conductive ceramic.

3. A sensor according to claim 2, characterized in that the electrically conductive ceramic is formed from ceramic powder, including silicide, carbonate and/or nitride powder, and at least one element consisting of a tungsten, tantalum, niobium, titanium, molybdenum, zirconium, hafnium, vanadium and/or chromium group, and that the electrically insulating ceramic is formed from thermally conductive ceramic powder, including silicon nitrite and/or aluminum nitride.

4. Sensor according to any of the preceding claims, characterized in that the all-ceramic heater (3, 3') has a thickness of 0.3mm to 3mm, preferably 0.5mm to 1.5 mm.

5. A sensor according to any preceding claim, wherein the sensor has:

at least one first insulating layer (7) arranged at least partially on a first side of the all-ceramic heater (3, 3'), and/or

At least one second insulation layer (7') arranged at least partially on a second side of the all-ceramic heater (3, 3') arranged opposite to the first side.

6. Sensor according to claim 5, characterized in that the first insulating layer (7) and/or the second insulating layer (7') comprise an electrically insulating ceramic.

7. Sensor according to one of the preceding claims, characterized in that the first sensor structure (9) and/or the second sensor structure (9') arranged on the first side or on the second side of the all-ceramic heater (3, 3') comprises at least one resistance structure for temperature measurement, in particular a measuring resistance in the shape of a loop.

8. Sensor according to any of the preceding claims, characterized in that the first sensor structure (9) and/or the second sensor structure (9') arranged on the first side or on the second side of the all-ceramic heater (3, 3') comprises at least one comb structure for measuring the concentration of deposits of soot particles, an IDK structure.

9. Sensor according to any of the preceding claims, characterized in that the first sensor structure (9) and/or the second sensor structure (9') arranged on the first side or on the second side of the all-ceramic heater (3, 3') comprises at least one electric heating element and at least one temperature sensor for wind measurement.

10. A sensor according to any one of the preceding claims, characterized in that the first sensor structure (9) and/or the second sensor structure (9') comprise at least one platinum material.

11. The sensor of any one of the preceding claims,

the sensor has:

at least one first ceramic intermediate layer (11) arranged at least partially on the first sensor structure (9); and/or

At least one second ceramic intermediate layer (11') arranged at least partially on the second sensor structure (9'), wherein the first (11) and/or second (11') ceramic intermediate layer preferably comprises aluminum oxide and/or magnesium oxide.

12. The sensor of claim 11,

the sensor has:

at least one first cover layer (13) arranged at least partially on the first ceramic intermediate layer (11); and/or

At least one second cover layer (13') arranged at least partially on the second ceramic intermediate layer (11').

13. Use of a sensor according to one of the preceding claims, in particular in the exhaust system of a motor vehicle, as a temperature sensor, soot sensor, flow sensor and/or multisensor, which multisensor comprises a combination of a temperature sensor, soot sensor and/or flow sensor.

14. A method of manufacturing a sensor, in particular a high temperature sensor, comprising the steps of:

providing (1010) at least one all-ceramic heater (3, 3'); and

at least one first sensor structure (9) is arranged (1015) at least partially on a first side of the all-ceramic heater (3, 3').

15. The method of claim 14, wherein the providing (1010) comprises:

-manufacturing (1005) the all-ceramic heater (3, 3') by means of co-sintering of electrically conductive and electrically insulating ceramics; and/or

Wherein the setting (1015) comprises:

the first insulating layer (7) is printed, in particular in a thin-film technique, with a platinum material.

Technical Field

The invention relates to a sensor for determining a gas parameter according to independent claim 1. The invention also relates to a method of manufacturing a sensor.

Background

Disclosure of Invention

In view of the above, it is an object of the present invention to provide an improved sensor that overcomes the disadvantages of the prior art. In particular, a high temperature resistant sensor is provided, which is inexpensive to manufacture.

The solution of the invention to achieve the above object is a sensor according to the subject matter of claim 1.

To this end, the sensor (in particular, a high-temperature sensor) of the present invention includes:

at least one all-ceramic heater; and

at least one first sensor structure at least partially disposed on a first side of the all-ceramic heater.

The term "all-ceramic heater" may refer to a heater including a heat generating body made of conductive ceramics and a sheath made of electrically insulating ceramics. The electrically conductive ceramic and the electrically insulating ceramic may be sintered into a homogeneous body.

The region of electrically conductive ceramic and the region of electrically insulating ceramic are preferably combined to form a green body and the all-ceramic heater is produced by co-sintering, i.e. in a common sintering step. Thus, in examples of the invention, the all-ceramic heater is also referred to as a "co-fired all-ceramic heater".

Within the scope of the present invention, a "sensor configuration" may refer to any configuration suitable for detecting at least one gas parameter of a gas flowing through.

The invention is based on the following surprising recognition: sensors with reduced precious metal content can be manufactured because all-ceramic heaters are generally constructed without precious metal components. Only electrodes, for example feed lines possibly comprising noble metal components, may be applied in contact with the ceramic. In an example of the invention, the electrodes may further advantageously likewise be formed from an electrically conductive ceramic which does not substantially comprise any noble metal components.

The invention provides for the first time a sensor for high-temperature applications which is resistant to high temperatures of more than 1000 ℃ and rapid temperature changes without causing damage or drift in the process, i.e. without causing a change in the output signal of the sensor, without causing a change in the magnitude to be measured.

It is further advantageous that the sensor has a larger space for the sensor structure than the similarly sized sensors disclosed in the prior art, since in the sensor of the invention no heating means on the surface of the support element or substrate arranged around or in the sensor structure is necessary.

Likewise, the good ageing and wear resistance of the ceramic ensures a long service life of the heater. Temperatures of up to 1000 ℃ can be reliably detected with the aid of an all-ceramic heater constructed in the manner described above. Other advantages of all-ceramic heaters are shorter heating times, less waste heat, improved controllability, increased service life at high temperatures and higher mechanical strength.

Another advantage of the sensor on an all-ceramic heater is that it can be applied in an electrically conductive medium, such as a liquid or an ionized gas. Unlike bare heaters, there is no risk of short circuits based on the electrically insulating sheath of an all-ceramic heater.

In one example, the all-ceramic heater has at least one electrically conductive ceramic, which is preferably in contact with the electrodes at least two locations separated from one another. Furthermore, the all-ceramic heater has at least one electrically insulating ceramic, wherein the electrically insulating ceramic at least partially surrounds, preferably completely surrounds, the electrically conductive ceramic.

The conductive ceramics may also be referred to as a heat generator or a heat resistor. The task of the conductive ceramic is to convert electrical energy into thermal energy. For this purpose, the conductive ceramic preferably has a low specific resistance, for example in the region of 5 x 10^-3Omega cm to 5 x 10^-1Specific resistance in the range of omega cm, so that the ceramic is electrifiedThe temperature is raised under the condition. The resistance of the heat-generating body can be determined by the spatial layout of the electrodes on the ceramic, and is formed by the resistance path between the electrodes.

In this connection, the term "electrode" may be applied to denote an electrical conductor or a region of an electrical conductor, for example a connection pad, which is electrically connected to the electrically conductive ceramic.

According to the invention, the electrically conductive ceramic is at least partially surrounded by an electrically insulating ceramic. In one example, the electrically conductive ceramic is encapsulated in an electrically insulating ceramic, even hermetically encapsulated. Thus, the surface of the all-ceramic heater may be formed from an electrically insulating ceramic, and the first sensor structure is arranged on the electrically insulating ceramic.

The electrodes may be made through the electrically insulating ceramic so that electrical contact can be made with the all-ceramic heater, for example by connecting the all-ceramic heater to a power source via the electrodes. The electrodes may be, for example, metal wires.

The all-ceramic heater may be shaped into a so-called "green body", for example, by extruding at least one ceramic powder into a suitable shape. But other forming processes such as casting, extrusion, injection molding, pressure grouting, etc. may be equally applied to make the green body depending on the intended use. After the green compact is manufactured, the green compact may be sintered under a nitrogen atmosphere. One possible production method is described, for example, in EP 0384342 a 1.

Furthermore, the electrically insulating or conductive ceramic may comprise a mixture of two or more powders, in order to better determine, for example, the mechanical properties of the ceramic.

Advantageously, the ratio between the powders can be varied depending on the particular intended range of use of the resulting sensor, so that the ceramic can have different electrical and/or thermal properties depending on the powder content.

The powders may likewise be homogeneously mixed so that the material properties of the ceramic are substantially the same over the entire extension of the ceramic. Alternatively, the ceramic may also have an irregular mixing of powders in certain regions to have better/poorer electrical and/or thermal conductivity in these regions depending on the particular intended range of use of the resulting sensor.

In one example, the electrically conductive ceramic is formed from a ceramic powder, including a silicide, carbonate, and/or nitride powder, and at least one element consisting of a tungsten, tantalum, niobium, titanium, molybdenum, zirconium, hafnium, vanadium, and/or chromium group, and the electrically insulating ceramic is formed from a thermally conductive ceramic powder, including a silicon nitrite and/or aluminum nitride.

The elements of the ceramic powder of the electrically conductive ceramic advantageously act such that the electrically conductive ceramic has a low specific resistance. Furthermore, the elements of the ceramic powder of the electrically insulating ceramic advantageously act such that the electrically insulating ceramic has a greater strength value and greater oxidation resistance.

In another example, the all-ceramic heater has a thickness of 0.3mm to 3mm, and preferably the all-ceramic heater has a thickness of 0.5mm to 1.5 mm.

Advantageously, extremely thin all-ceramic heaters can be realized, on which the first sensor structure can be arranged and which are already capable of providing sufficient thermal power to heat the first sensor structure.

In another example, the sensor has:

at least one first insulating layer and/or at least one first insulating layer arranged at least partially on a first side of the all-ceramic heater

At least one second insulating layer at least partially disposed on a second side of the all-ceramic heater disposed opposite the first side.

Depending on the applied all-ceramic heater, the first and/or second insulating layer can either be arranged on the electrically conductive ceramic or already on the electrically insulating ceramic and serve as an electrical insulator between the electrically conductive ceramic and the sensor structure. Further advantageously, the first and/or second insulating layer may be used as an adhesion promoter for the sensor structure.

In another example, the first insulating layer and/or the second insulating layer comprise an electrically insulating ceramic.

The electrically insulating ceramic may have good thermal conductivity, and thus, the generated heat may be caused to pass through the electrically insulating ceramic. In one example, the second insulating layer may include the same material as the first insulating layer. The second insulating layer can likewise comprise an electrically insulating ceramic having different insulating and/or thermal conductivity properties than the first insulating layer.

In one example, the first sensor structure and/or the second sensor structure arranged on the first side or on the second side of the all-ceramic heater comprises at least one resistance structure for temperature measurement, in particular a measuring resistance in the shape of a loop.

The measuring resistor can be formed by a circuit having an arc-shaped course between the two electrodes. The circuit can be designed, for example, in a loop shape. Such a measuring resistor can be arranged only on one side of the all-ceramic heater, either on the first side or on the second side. In another example, a measuring resistor may also be arranged on both sides of the all-ceramic heater.

Advantageously, the sensor structure may extend over the entire surface of the all-ceramic heater, since there is no need to arrange any separate heating element on the surface of the all-ceramic heater.

In another example, the first sensor structure and/or the second sensor structure arranged on the first side or on the second side of the all-ceramic heater comprises at least one comb structure, an IDK structure, for measuring a concentration of deposits of soot (soot) particles.

The IDK structure may be generally used to determine soot particles in a soot sensor.

In one example, the first sensor structure and/or the second sensor structure arranged on the first side or on the second side of the all-ceramic heater comprises at least one electric heating element and at least one temperature sensor for wind measurement.

Such sensor arrangements can be used in through-flow sensors, which can also be referred to as flow sensors, in order to measure the flow in a channel, for example in an exhaust system.

Different sensor structures can also be arranged on both sides of the all-ceramic heater in order to determine different sizes. Such sensors may be referred to as multisensors.

In another example, the first sensor structure and/or the second sensor structure includes at least one platinum material.

The sensor structure can advantageously have a platinum resistance as the measuring resistance.

In another example, the sensor element has:

at least one first ceramic intermediate layer arranged at least partially on the first sensor structure; and/or at least one second ceramic intermediate layer arranged at least partially on the second sensor structure, wherein the first and/or the second ceramic intermediate layer preferably comprises aluminum oxide and/or magnesium oxide.

Such a ceramic intermediate layer can advantageously be used as a diffusion barrier, as described in DE 102007046900B 4.

In another example, the sensor has:

at least one first cover layer arranged at least partially on the first ceramic intermediate layer; and/or

At least one second cover layer arranged at least partially on the second ceramic intermediate layer.

As is also described in DE 102007046900B 4, such a cover layer can be arranged as a passivation layer on the ceramic intermediate layer, which passivation layer can comprise, for example, quartz glass and optionally ceramic.

The invention also proposes a sensor according to one of the preceding claims, which is embodied in particular in the exhaust system of a motor vehicle as a temperature sensor, soot sensor, flow sensor and/or as a multisensor, which comprises a combination of a temperature sensor, soot sensor and/or flow sensor.

Furthermore, the invention proposes a method for producing a sensor, in particular a high-temperature sensor, comprising the following steps:

providing at least one all-ceramic heater; and

at least one first sensor structure is arranged at least partially on a first side of the all-ceramic heater.

As described in EP 0763693B 1, a ceramic heater can advantageously be used as a substrate and a sensor structure can be arranged on the ceramic heater. This advantageously allows the sensor to be manufactured in a simple and cost-effective manner.

In one example, the method is characterized in that the providing comprises:

fabricating the all-ceramic heater by co-sintering of electrically conductive and electrically insulating ceramics; and/or

Wherein the setting comprises:

in particular, the first insulating layer is printed with platinum material in thin film technology.

But it is equally possible to arrange the platinum material on the substrate in thick film technology, for example. For this purpose, platinum powder may be mixed with an oxide and a binder and provided onto the substrate by screen printing. Subsequently, annealing may be performed.

Drawings

Further features and advantages of the invention reference is made to the following description of a preferred embodiment of the invention, taken in conjunction with the accompanying schematic drawings.

In the figure:

FIG. 1 is an exploded schematic view of a sensor according to an embodiment of the present invention;

FIG. 2 is a schematic view of the layering of an all ceramic heater according to an embodiment of the present invention;

FIGS. 3a, 3b are schematic views of an all-ceramic heater according to an embodiment of the invention, as exploded views, and views of the all-ceramic heater in a consolidated state; and

fig. 4 is a method of manufacturing a sensor according to an embodiment of the present invention.

Detailed Description

Fig. 1 shows an exploded schematic view of a sensor 1 according to an embodiment of the invention. The exemplary sensor 1 shown has an all-ceramic heater 3, which includes a heat generating body made of conductive ceramic and a sheath made of electrically insulating ceramic. In the illustrated embodiment, the electrically conductive ceramic and the electrically insulating ceramic are sintered into a homogeneous body.

Fig. 1 also shows two electrodes 5a, 5b arranged on the all-ceramic heater 3. In the embodiment shown, the electrodes 5a, 5b are designed as feed lines. The electrodes 5a, 5b are in contact with the conductive ceramic at two different locations, so that the region of the conductive ceramic between the electrodes 5a, 5b is designed as a heat generator or a thermal resistor. An energy source, for example a current source (not shown in fig. 1), can be connected to the electrodes 5a, 5b, so that the ceramic heats up when energized. The resistance of the heating body can be measured by arranging the electrodes 5a, 5b on the ceramic, and the resistance is formed by the resistance path between the electrodes 5a, 5 b. In the embodiment shown in fig. 1, the electrodes 5a, 5b are arranged side by side on one side of the all-ceramic heater 3. However, the person skilled in the art knows that in an embodiment not shown, the electrodes 5a, 5b can likewise be arranged at other locations of the all-ceramic heater 3, for example on opposite sides of the all-ceramic heater 3. Furthermore, in a not shown embodiment, also more than two electrodes can be arranged on the all-ceramic heater 3. For example, four electrodes can be arranged on the all-ceramic heater 3 and can be in electrical contact with the electrically conductive ceramic in order to connect two mutually independent circuits. In this way, in this embodiment, which is not shown, two independently switchable thermal resistors can be formed, which have different thermal powers in the all-ceramic heater.

Alternatively, the embodiment shown in fig. 1 shows a first insulating layer 7, which is arranged on a first side of the all-ceramic heater 3. The first insulating layer 7 can be produced, for example, by screen printing of an electrically insulating ceramic paste. Alternatively, the first insulating layer 7 can also be produced by coating a metal oxide by means of methods such as sputtering, thermal evaporation or aerosol deposition. The first insulating layer 7 may cover the entire surface of the all-ceramic heater 3, or may be arranged only on a section of the surface of the all-ceramic heater 3. In a not shown embodiment, a recess can also be introduced into the material of the first insulating layer, so that the electrode can be contacted via the first insulating layer.

A first sensor structure 9, which may be embodied, for example, as a platinum resistor structure, is arranged on the all-ceramic heater 3 or on the optionally provided first insulating layer 7. The illustrated first sensor arrangement 9 shows a meander-shaped resistance structure which may be applied for temperature measurement, for example. As shown in fig. 1, the meander-shaped resistive structure may have two connection contacts for connecting the resistive structure to an electronic analysis device (not shown in fig. 1). As an alternative or in addition to the resistive structure shown, in embodiments not shown, there may also be other sensor structures and/or heating elements arranged on the first surface of the all-ceramic heater 3.

For example, IDK structures can be arranged as an alternative or in addition to loop-shaped resistor structures for determining soot particles.

Furthermore, fig. 1 merely shows that, as an alternative, the first sensor structure 9 and the regions of the all-ceramic heater 3 which are not covered by the first sensor structure 9 can be at least partially covered by a ceramic intermediate layer 11. The intermediate layer 11 of ceramic may in turn only optionally be at least partially covered by a cover layer 13. However, the person skilled in the art knows that the intermediate layer 11 and/or the cover layer 13 are not necessary for the application of the sensor 1 shown in fig. 1 embodied as a temperature sensor, soot sensor, flow sensor and/or multisensor in the exhaust system of a motor vehicle.

In the embodiment shown in fig. 1, a second insulating layer 7', which may comprise the same material as the first insulating layer 7, is arranged on the second side of the all-ceramic heater 3.

In the embodiment shown, an IDK structure for determining soot particles is mounted on the all-ceramic heater 3, as an example, as a second sensor structure 9'. In alternative embodiments, not shown, the second sensor arrangement 9' may also comprise other/alternative arrangements adapted to detect one or several gas parameters of the gas flowing through.

As already described with respect to the first side of the all-ceramic heater 3, a ceramic intermediate layer 11' can also be arranged at least in regions on the second sensor structure 9', on which intermediate layer a cover layer 13' can in turn be arranged at least in regions.

The arrangement of these structures on the second side of the substrate 3 is not critical to the invention. The sensor 1 of the invention may likewise comprise only the all-ceramic heater 3, the first insulating layer 7 and the first sensor structure 9.

Fig. 2 shows a layered schematic of an all-ceramic heater 3' according to an embodiment of the invention. The layered diagram shown in fig. 2 may be a structural diagram of the all-ceramic heater 3 already shown in fig. 1.

The left column in fig. 2 shows several substantially identical layers 15-23 of compacted, electrically insulating ceramic powder for use as a so-called "green body". As shown in fig. 2, the layers 15-23 are designed substantially rectangular. In embodiments not shown, however, the layers may also have other geometric shapes, and the layers may be circular or oval, for example.

The middle column of fig. 2 shows three layers 17'-21', which may be the layers 17-21 shown in the left column, with grooves that may be introduced, for example, by stamping. The layers 17 'and 21' are formed with geometries for contacting the heating element with the electrodes. The layer 19' is formed with a geometry for the heating element. The shown geometries are only exemplary and it is also possible to design different geometries than those shown, depending on the intended use, the heat generating body for example being designed as a rod or a meander.

The right column of fig. 3 shows three layers 17 "-21", which may be layers 17'-21' shown in the middle column, with conductive ceramic powder introduced into the grooves.

Fig. 3a and 3b show a schematic view of an all-ceramic heater 3' according to an embodiment of the invention as an exploded view and a view in a merged state.

Figure 3a shows that the layers 15, 17 ", 19", 21 "and 23 shown in figure 2 are arranged on a palletized tier. On the contacts shown in fig. 2, electrodes 5a ', 5b' in the form of contact pins or connecting wires in the embodiment shown in fig. 3a are arranged to be in contact with the heating body.

Fig. 3b shows the palletized tier of fig. 3a in a consolidated state. The layers can be connected to each other, for example, by means of sintering. Sintering may be carried out, for example, at a temperature of 1600-2000 c under a nitrogen atmosphere.

Fig. 4 shows a method 1000 of manufacturing a sensor 1 according to an embodiment of the invention. The method 1000 has the steps of:

providing 1010 at least one all-ceramic heater 3; and

at least one first sensor structure 9 is arranged 1015 at least locally on a first side of the all-ceramic heater 3.

Furthermore, providing 1010 may also include fabricating 1005 the all-ceramic heater 3, 3' by co-sintering of electrically conductive and electrically insulating ceramics. The frame of this step is shown in dashed lines in fig. 4, as the fabrication 1005 of an all ceramic heater is only optional.

The features mentioned in the description, the claims and the drawings can be of significance both individually and in any combination in the different embodiments thereof.

List of reference numerals

1 sensor

3. 3' full ceramic heater

5a, 5a ', 5b' electrode

7. 7' insulating layer

9. 9' sensor structure

11. 11' ceramic intermediate layer

13. 13' coating layer

15 first layer

17. 17', 17' second layer

19. 19', 19' third layer

21. 21', 21' fourth layer

23 fifth layer

1000 method of manufacturing a sensor

1005 manufacture

1010 supply

1015 arrangement